CbC/CbC_llvm: tools/clang/docs/LanguageExtensions.rst annotate

annotate tools/clang/docs/LanguageExtensions.rst @ 95:afa8332a0e37 LLVM3.8

LLVM 3.8

author	Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date	Tue, 13 Oct 2015 17:48:58 +0900
parents	60c9769439b8
children	7d135dc70f03

rev	line source
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1 =========================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2 Clang Language Extensions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	3 =========================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	4
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	5 .. contents::
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	6 :local:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	7 :depth: 1
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	8
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	9 .. toctree::
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	10 :hidden:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	11
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	12 ObjectiveCLiterals
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	13 BlockLanguageSpec
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	14 Block-ABI-Apple
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	15 AutomaticReferenceCounting
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	16
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	17 Introduction
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	18 ============
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	19
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	20 This document describes the language extensions provided by Clang. In addition
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	21 to the language extensions listed here, Clang aims to support a broad range of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	22 GCC extensions. Please see the `GCC manual
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	23 <http://gcc.gnu.org/onlinedocs/gcc/C-Extensions.html>`_ for more information on
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	24 these extensions.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	25
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	26 .. _langext-feature_check:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	27
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	28 Feature Checking Macros
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	29 =======================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	30
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	31 Language extensions can be very useful, but only if you know you can depend on
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	32 them. In order to allow fine-grain features checks, we support three builtin
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	33 function-like macros. This allows you to directly test for a feature in your
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	34 code without having to resort to something like autoconf or fragile "compiler
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	35 version checks".
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	36
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	37 ``__has_builtin``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	38 -----------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	39
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	40 This function-like macro takes a single identifier argument that is the name of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	41 a builtin function. It evaluates to 1 if the builtin is supported or 0 if not.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	42 It can be used like this:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	43
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	44 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	45
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	46 #ifndef __has_builtin // Optional of course.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	47 #define __has_builtin(x) 0 // Compatibility with non-clang compilers.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	48 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	49
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	50 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	51 #if __has_builtin(__builtin_trap)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	52 __builtin_trap();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	53 #else
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	54 abort();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	55 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	56 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	57
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	58 .. _langext-__has_feature-__has_extension:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	59
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	60 ``__has_feature`` and ``__has_extension``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	61 -----------------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	62
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	63 These function-like macros take a single identifier argument that is the name
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	64 of a feature. ``__has_feature`` evaluates to 1 if the feature is both
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	65 supported by Clang and standardized in the current language standard or 0 if
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	66 not (but see :ref:`below <langext-has-feature-back-compat>`), while
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	67 ``__has_extension`` evaluates to 1 if the feature is supported by Clang in the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	68 current language (either as a language extension or a standard language
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	69 feature) or 0 if not. They can be used like this:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	70
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	71 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	72
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	73 #ifndef __has_feature // Optional of course.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	74 #define __has_feature(x) 0 // Compatibility with non-clang compilers.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	75 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	76 #ifndef __has_extension
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	77 #define __has_extension __has_feature // Compatibility with pre-3.0 compilers.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	78 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	79
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	80 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	81 #if __has_feature(cxx_rvalue_references)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	82 // This code will only be compiled with the -std=c++11 and -std=gnu++11
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	83 // options, because rvalue references are only standardized in C++11.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	84 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	85
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	86 #if __has_extension(cxx_rvalue_references)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	87 // This code will be compiled with the -std=c++11, -std=gnu++11, -std=c++98
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	88 // and -std=gnu++98 options, because rvalue references are supported as a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	89 // language extension in C++98.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	90 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	91
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	92 .. _langext-has-feature-back-compat:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	93
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	94 For backward compatibility, ``__has_feature`` can also be used to test
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	95 for support for non-standardized features, i.e. features not prefixed ``c_``,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	96 ``cxx_`` or ``objc_``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	97
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	98 Another use of ``__has_feature`` is to check for compiler features not related
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	99 to the language standard, such as e.g. :doc:`AddressSanitizer
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	100 <AddressSanitizer>`.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	101
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	102 If the ``-pedantic-errors`` option is given, ``__has_extension`` is equivalent
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	103 to ``__has_feature``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	104
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	105 The feature tag is described along with the language feature below.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	106
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	107 The feature name or extension name can also be specified with a preceding and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	108 following ``__`` (double underscore) to avoid interference from a macro with
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	109 the same name. For instance, ``__cxx_rvalue_references__`` can be used instead
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	110 of ``cxx_rvalue_references``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	111
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	112 ``__has_cpp_attribute``
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	113 -----------------------
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	114
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	115 This function-like macro takes a single argument that is the name of a
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	116 C++11-style attribute. The argument can either be a single identifier, or a
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	117 scoped identifier. If the attribute is supported, a nonzero value is returned.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	118 If the attribute is a standards-based attribute, this macro returns a nonzero
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	119 value based on the year and month in which the attribute was voted into the
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	120 working draft. If the attribute is not supported by the current compliation
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	121 target, this macro evaluates to 0. It can be used like this:
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	122
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	123 .. code-block:: c++
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	124
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	125 #ifndef __has_cpp_attribute // Optional of course.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	126 #define __has_cpp_attribute(x) 0 // Compatibility with non-clang compilers.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	127 #endif
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	128
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	129 ...
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	130 #if __has_cpp_attribute(clang::fallthrough)
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	131 #define FALLTHROUGH [[clang::fallthrough]]
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	132 #else
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	133 #define FALLTHROUGH
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	134 #endif
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	135 ...
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	136
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	137 The attribute identifier (but not scope) can also be specified with a preceding
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	138 and following ``__`` (double underscore) to avoid interference from a macro with
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	139 the same name. For instance, ``gnu::__const__`` can be used instead of
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	140 ``gnu::const``.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	141
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	142 ``__has_attribute``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	143 -------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	144
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	145 This function-like macro takes a single identifier argument that is the name of
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	146 a GNU-style attribute. It evaluates to 1 if the attribute is supported by the
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	147 current compilation target, or 0 if not. It can be used like this:
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	148
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	149 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	150
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	151 #ifndef __has_attribute // Optional of course.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	152 #define __has_attribute(x) 0 // Compatibility with non-clang compilers.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	153 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	154
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	155 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	156 #if __has_attribute(always_inline)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	157 #define ALWAYS_INLINE __attribute__((always_inline))
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	158 #else
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	159 #define ALWAYS_INLINE
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	160 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	161 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	162
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	163 The attribute name can also be specified with a preceding and following ``__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	164 (double underscore) to avoid interference from a macro with the same name. For
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	165 instance, ``__always_inline__`` can be used instead of ``always_inline``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	166
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	167
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	168 ``__has_declspec_attribute``
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	169 ----------------------------
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	170
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	171 This function-like macro takes a single identifier argument that is the name of
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	172 an attribute implemented as a Microsoft-style ``__declspec`` attribute. It
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	173 evaluates to 1 if the attribute is supported by the current compilation target,
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	174 or 0 if not. It can be used like this:
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	175
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	176 .. code-block:: c++
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	177
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	178 #ifndef __has_declspec_attribute // Optional of course.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	179 #define __has_declspec_attribute(x) 0 // Compatibility with non-clang compilers.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	180 #endif
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	181
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	182 ...
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	183 #if __has_declspec_attribute(dllexport)
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	184 #define DLLEXPORT __declspec(dllexport)
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	185 #else
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	186 #define DLLEXPORT
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	187 #endif
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	188 ...
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	189
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	190 The attribute name can also be specified with a preceding and following ``__``
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	191 (double underscore) to avoid interference from a macro with the same name. For
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	192 instance, ``__dllexport__`` can be used instead of ``dllexport``.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	193
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	194 ``__is_identifier``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	195 -------------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	196
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	197 This function-like macro takes a single identifier argument that might be either
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	198 a reserved word or a regular identifier. It evaluates to 1 if the argument is just
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	199 a regular identifier and not a reserved word, in the sense that it can then be
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	200 used as the name of a user-defined function or variable. Otherwise it evaluates
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	201 to 0. It can be used like this:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	202
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	203 .. code-block:: c++
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	204
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	205 ...
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	206 #ifdef __is_identifier // Compatibility with non-clang compilers.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	207 #if __is_identifier(__wchar_t)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	208 typedef wchar_t __wchar_t;
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	209 #endif
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	210 #endif
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	211
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	212 __wchar_t WideCharacter;
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	213 ...
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	214
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	215 Include File Checking Macros
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	216 ============================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	217
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	218 Not all developments systems have the same include files. The
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	219 :ref:`langext-__has_include` and :ref:`langext-__has_include_next` macros allow
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	220 you to check for the existence of an include file before doing a possibly
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	221 failing ``#include`` directive. Include file checking macros must be used
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	222 as expressions in ``#if`` or ``#elif`` preprocessing directives.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	223
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	224 .. _langext-__has_include:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	225
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	226 ``__has_include``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	227 -----------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	228
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	229 This function-like macro takes a single file name string argument that is the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	230 name of an include file. It evaluates to 1 if the file can be found using the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	231 include paths, or 0 otherwise:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	232
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	233 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	234
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	235 // Note the two possible file name string formats.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	236 #if __has_include("myinclude.h") && __has_include(<stdint.h>)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	237 # include "myinclude.h"
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	238 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	239
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	240 To test for this feature, use ``#if defined(__has_include)``:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	241
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	242 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	243
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	244 // To avoid problem with non-clang compilers not having this macro.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	245 #if defined(__has_include)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	246 #if __has_include("myinclude.h")
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	247 # include "myinclude.h"
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	248 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	249 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	250
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	251 .. _langext-__has_include_next:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	252
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	253 ``__has_include_next``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	254 ----------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	255
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	256 This function-like macro takes a single file name string argument that is the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	257 name of an include file. It is like ``__has_include`` except that it looks for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	258 the second instance of the given file found in the include paths. It evaluates
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	259 to 1 if the second instance of the file can be found using the include paths,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	260 or 0 otherwise:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	261
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	262 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	263
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	264 // Note the two possible file name string formats.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	265 #if __has_include_next("myinclude.h") && __has_include_next(<stdint.h>)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	266 # include_next "myinclude.h"
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	267 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	268
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	269 // To avoid problem with non-clang compilers not having this macro.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	270 #if defined(__has_include_next)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	271 #if __has_include_next("myinclude.h")
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	272 # include_next "myinclude.h"
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	273 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	274 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	275
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	276 Note that ``__has_include_next``, like the GNU extension ``#include_next``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	277 directive, is intended for use in headers only, and will issue a warning if
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	278 used in the top-level compilation file. A warning will also be issued if an
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	279 absolute path is used in the file argument.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	280
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	281 ``__has_warning``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	282 -----------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	283
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	284 This function-like macro takes a string literal that represents a command line
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	285 option for a warning and returns true if that is a valid warning option.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	286
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	287 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	288
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	289 #if __has_warning("-Wformat")
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	290 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	291 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	292
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	293 Builtin Macros
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	294 ==============
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	295
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	296 ``__BASE_FILE__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	297 Defined to a string that contains the name of the main input file passed to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	298 Clang.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	299
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	300 ``__COUNTER__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	301 Defined to an integer value that starts at zero and is incremented each time
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	302 the ``__COUNTER__`` macro is expanded.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	303
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	304 ``__INCLUDE_LEVEL__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	305 Defined to an integral value that is the include depth of the file currently
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	306 being translated. For the main file, this value is zero.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	307
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	308 ``__TIMESTAMP__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	309 Defined to the date and time of the last modification of the current source
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	310 file.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	311
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	312 ``__clang__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	313 Defined when compiling with Clang
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	314
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	315 ``__clang_major__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	316 Defined to the major marketing version number of Clang (e.g., the 2 in
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	317 2.0.1). Note that marketing version numbers should not be used to check for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	318 language features, as different vendors use different numbering schemes.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	319 Instead, use the :ref:`langext-feature_check`.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	320
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	321 ``__clang_minor__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	322 Defined to the minor version number of Clang (e.g., the 0 in 2.0.1). Note
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	323 that marketing version numbers should not be used to check for language
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	324 features, as different vendors use different numbering schemes. Instead, use
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	325 the :ref:`langext-feature_check`.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	326
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	327 ``__clang_patchlevel__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	328 Defined to the marketing patch level of Clang (e.g., the 1 in 2.0.1).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	329
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	330 ``__clang_version__``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	331 Defined to a string that captures the Clang marketing version, including the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	332 Subversion tag or revision number, e.g., "``1.5 (trunk 102332)``".
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	333
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	334 .. _langext-vectors:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	335
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	336 Vectors and Extended Vectors
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	337 ============================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	338
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	339 Supports the GCC, OpenCL, AltiVec and NEON vector extensions.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	340
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	341 OpenCL vector types are created using ``ext_vector_type`` attribute. It
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	342 support for ``V.xyzw`` syntax and other tidbits as seen in OpenCL. An example
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	343 is:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	344
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	345 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	346
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	347 typedef float float4 __attribute__((ext_vector_type(4)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	348 typedef float float2 __attribute__((ext_vector_type(2)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	349
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	350 float4 foo(float2 a, float2 b) {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	351 float4 c;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	352 c.xz = a;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	353 c.yw = b;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	354 return c;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	355 }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	356
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	357 Query for this feature with ``__has_extension(attribute_ext_vector_type)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	358
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	359 Giving ``-faltivec`` option to clang enables support for AltiVec vector syntax
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	360 and functions. For example:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	361
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	362 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	363
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	364 vector float foo(vector int a) {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	365 vector int b;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	366 b = vec_add(a, a) + a;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	367 return (vector float)b;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	368 }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	369
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	370 NEON vector types are created using ``neon_vector_type`` and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	371 ``neon_polyvector_type`` attributes. For example:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	372
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	373 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	374
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	375 typedef __attribute__((neon_vector_type(8))) int8_t int8x8_t;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	376 typedef __attribute__((neon_polyvector_type(16))) poly8_t poly8x16_t;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	377
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	378 int8x8_t foo(int8x8_t a) {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	379 int8x8_t v;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	380 v = a;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	381 return v;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	382 }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	383
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	384 Vector Literals
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	385 ---------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	386
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	387 Vector literals can be used to create vectors from a set of scalars, or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	388 vectors. Either parentheses or braces form can be used. In the parentheses
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	389 form the number of literal values specified must be one, i.e. referring to a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	390 scalar value, or must match the size of the vector type being created. If a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	391 single scalar literal value is specified, the scalar literal value will be
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	392 replicated to all the components of the vector type. In the brackets form any
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	393 number of literals can be specified. For example:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	394
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	395 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	396
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	397 typedef int v4si __attribute__((__vector_size__(16)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	398 typedef float float4 __attribute__((ext_vector_type(4)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	399 typedef float float2 __attribute__((ext_vector_type(2)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	400
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	401 v4si vsi = (v4si){1, 2, 3, 4};
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	402 float4 vf = (float4)(1.0f, 2.0f, 3.0f, 4.0f);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	403 vector int vi1 = (vector int)(1); // vi1 will be (1, 1, 1, 1).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	404 vector int vi2 = (vector int){1}; // vi2 will be (1, 0, 0, 0).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	405 vector int vi3 = (vector int)(1, 2); // error
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	406 vector int vi4 = (vector int){1, 2}; // vi4 will be (1, 2, 0, 0).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	407 vector int vi5 = (vector int)(1, 2, 3, 4);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	408 float4 vf = (float4)((float2)(1.0f, 2.0f), (float2)(3.0f, 4.0f));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	409
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	410 Vector Operations
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	411 -----------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	412
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	413 The table below shows the support for each operation by vector extension. A
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	414 dash indicates that an operation is not accepted according to a corresponding
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	415 specification.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	416
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	417 ============================== ======= ======= ======= =======
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	418 Operator OpenCL AltiVec GCC NEON
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	419 ============================== ======= ======= ======= =======
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	420 [] yes yes yes --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	421 unary operators +, -- yes yes yes --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	422 ++, -- -- yes yes yes --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	423 +,--,*,/,% yes yes yes --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	424 bitwise operators &,\|,^,~ yes yes yes --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	425 >>,<< yes yes yes --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	426 !, &&, \|\| yes -- -- --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	427 ==, !=, >, <, >=, <= yes yes -- --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	428 = yes yes yes yes
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	429 :? yes -- -- --
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	430 sizeof yes yes yes yes
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	431 C-style cast yes yes yes no
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	432 reinterpret_cast yes no yes no
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	433 static_cast yes no yes no
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	434 const_cast no no no no
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	435 ============================== ======= ======= ======= =======
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	436
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	437 See also :ref:`langext-__builtin_shufflevector`, :ref:`langext-__builtin_convertvector`.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	438
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	439 Messages on ``deprecated`` and ``unavailable`` Attributes
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	440 =========================================================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	441
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	442 An optional string message can be added to the ``deprecated`` and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	443 ``unavailable`` attributes. For example:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	444
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	445 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	446
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	447 void explode(void) __attribute__((deprecated("extremely unsafe, use 'combust' instead!!!")));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	448
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	449 If the deprecated or unavailable declaration is used, the message will be
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	450 incorporated into the appropriate diagnostic:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	451
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	452 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	453
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	454 harmless.c:4:3: warning: 'explode' is deprecated: extremely unsafe, use 'combust' instead!!!
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	455 [-Wdeprecated-declarations]
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	456 explode();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	457 ^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	458
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	459 Query for this feature with
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	460 ``__has_extension(attribute_deprecated_with_message)`` and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	461 ``__has_extension(attribute_unavailable_with_message)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	462
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	463 Attributes on Enumerators
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	464 =========================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	465
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	466 Clang allows attributes to be written on individual enumerators. This allows
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	467 enumerators to be deprecated, made unavailable, etc. The attribute must appear
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	468 after the enumerator name and before any initializer, like so:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	469
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	470 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	471
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	472 enum OperationMode {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	473 OM_Invalid,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	474 OM_Normal,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	475 OM_Terrified __attribute__((deprecated)),
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	476 OM_AbortOnError __attribute__((deprecated)) = 4
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	477 };
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	478
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	479 Attributes on the ``enum`` declaration do not apply to individual enumerators.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	480
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	481 Query for this feature with ``__has_extension(enumerator_attributes)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	482
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	483 'User-Specified' System Frameworks
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	484 ==================================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	485
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	486 Clang provides a mechanism by which frameworks can be built in such a way that
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	487 they will always be treated as being "system frameworks", even if they are not
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	488 present in a system framework directory. This can be useful to system
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	489 framework developers who want to be able to test building other applications
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	490 with development builds of their framework, including the manner in which the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	491 compiler changes warning behavior for system headers.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	492
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	493 Framework developers can opt-in to this mechanism by creating a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	494 "``.system_framework``" file at the top-level of their framework. That is, the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	495 framework should have contents like:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	496
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	497 .. code-block:: none
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	498
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	499 .../TestFramework.framework
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	500 .../TestFramework.framework/.system_framework
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	501 .../TestFramework.framework/Headers
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	502 .../TestFramework.framework/Headers/TestFramework.h
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	503 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	504
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	505 Clang will treat the presence of this file as an indicator that the framework
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	506 should be treated as a system framework, regardless of how it was found in the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	507 framework search path. For consistency, we recommend that such files never be
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	508 included in installed versions of the framework.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	509
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	510 Checks for Standard Language Features
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	511 =====================================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	512
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	513 The ``__has_feature`` macro can be used to query if certain standard language
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	514 features are enabled. The ``__has_extension`` macro can be used to query if
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	515 language features are available as an extension when compiling for a standard
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	516 which does not provide them. The features which can be tested are listed here.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	517
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	518 Since Clang 3.4, the C++ SD-6 feature test macros are also supported.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	519 These are macros with names of the form ``__cpp_<feature_name>``, and are
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	520 intended to be a portable way to query the supported features of the compiler.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	521 See `the C++ status page <http://clang.llvm.org/cxx_status.html#ts>`_ for
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	522 information on the version of SD-6 supported by each Clang release, and the
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	523 macros provided by that revision of the recommendations.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	524
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	525 C++98
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	526 -----
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	527
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	528 The features listed below are part of the C++98 standard. These features are
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	529 enabled by default when compiling C++ code.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	530
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	531 C++ exceptions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	532 ^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	533
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	534 Use ``__has_feature(cxx_exceptions)`` to determine if C++ exceptions have been
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	535 enabled. For example, compiling code with ``-fno-exceptions`` disables C++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	536 exceptions.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	537
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	538 C++ RTTI
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	539 ^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	540
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	541 Use ``__has_feature(cxx_rtti)`` to determine if C++ RTTI has been enabled. For
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	542 example, compiling code with ``-fno-rtti`` disables the use of RTTI.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	543
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	544 C++11
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	545 -----
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	546
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	547 The features listed below are part of the C++11 standard. As a result, all
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	548 these features are enabled with the ``-std=c++11`` or ``-std=gnu++11`` option
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	549 when compiling C++ code.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	550
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	551 C++11 SFINAE includes access control
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	552 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	553
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	554 Use ``__has_feature(cxx_access_control_sfinae)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	555 ``__has_extension(cxx_access_control_sfinae)`` to determine whether
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	556 access-control errors (e.g., calling a private constructor) are considered to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	557 be template argument deduction errors (aka SFINAE errors), per `C++ DR1170
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	558 <http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#1170>`_.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	559
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	560 C++11 alias templates
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	561 ^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	562
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	563 Use ``__has_feature(cxx_alias_templates)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	564 ``__has_extension(cxx_alias_templates)`` to determine if support for C++11's
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	565 alias declarations and alias templates is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	566
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	567 C++11 alignment specifiers
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	568 ^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	569
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	570 Use ``__has_feature(cxx_alignas)`` or ``__has_extension(cxx_alignas)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	571 determine if support for alignment specifiers using ``alignas`` is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	572
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	573 Use ``__has_feature(cxx_alignof)`` or ``__has_extension(cxx_alignof)`` to
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	574 determine if support for the ``alignof`` keyword is enabled.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	575
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	576 C++11 attributes
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	577 ^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	578
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	579 Use ``__has_feature(cxx_attributes)`` or ``__has_extension(cxx_attributes)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	580 determine if support for attribute parsing with C++11's square bracket notation
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	581 is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	582
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	583 C++11 generalized constant expressions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	584 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	585
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	586 Use ``__has_feature(cxx_constexpr)`` to determine if support for generalized
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	587 constant expressions (e.g., ``constexpr``) is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	588
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	589 C++11 ``decltype()``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	590 ^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	591
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	592 Use ``__has_feature(cxx_decltype)`` or ``__has_extension(cxx_decltype)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	593 determine if support for the ``decltype()`` specifier is enabled. C++11's
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	594 ``decltype`` does not require type-completeness of a function call expression.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	595 Use ``__has_feature(cxx_decltype_incomplete_return_types)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	596 ``__has_extension(cxx_decltype_incomplete_return_types)`` to determine if
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	597 support for this feature is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	598
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	599 C++11 default template arguments in function templates
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	600 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	601
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	602 Use ``__has_feature(cxx_default_function_template_args)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	603 ``__has_extension(cxx_default_function_template_args)`` to determine if support
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	604 for default template arguments in function templates is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	605
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	606 C++11 ``default``\ ed functions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	607 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	608
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	609 Use ``__has_feature(cxx_defaulted_functions)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	610 ``__has_extension(cxx_defaulted_functions)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	611 defaulted function definitions (with ``= default``) is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	612
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	613 C++11 delegating constructors
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	614 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	615
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	616 Use ``__has_feature(cxx_delegating_constructors)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	617 delegating constructors is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	618
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	619 C++11 ``deleted`` functions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	620 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	621
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	622 Use ``__has_feature(cxx_deleted_functions)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	623 ``__has_extension(cxx_deleted_functions)`` to determine if support for deleted
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	624 function definitions (with ``= delete``) is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	625
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	626 C++11 explicit conversion functions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	627 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	628
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	629 Use ``__has_feature(cxx_explicit_conversions)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	630 ``explicit`` conversion functions is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	631
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	632 C++11 generalized initializers
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	633 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	634
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	635 Use ``__has_feature(cxx_generalized_initializers)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	636 generalized initializers (using braced lists and ``std::initializer_list``) is
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	637 enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	638
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	639 C++11 implicit move constructors/assignment operators
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	640 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	641
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	642 Use ``__has_feature(cxx_implicit_moves)`` to determine if Clang will implicitly
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	643 generate move constructors and move assignment operators where needed.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	644
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	645 C++11 inheriting constructors
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	646 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	647
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	648 Use ``__has_feature(cxx_inheriting_constructors)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	649 inheriting constructors is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	650
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	651 C++11 inline namespaces
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	652 ^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	653
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	654 Use ``__has_feature(cxx_inline_namespaces)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	655 ``__has_extension(cxx_inline_namespaces)`` to determine if support for inline
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	656 namespaces is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	657
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	658 C++11 lambdas
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	659 ^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	660
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	661 Use ``__has_feature(cxx_lambdas)`` or ``__has_extension(cxx_lambdas)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	662 determine if support for lambdas is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	663
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	664 C++11 local and unnamed types as template arguments
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	665 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	666
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	667 Use ``__has_feature(cxx_local_type_template_args)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	668 ``__has_extension(cxx_local_type_template_args)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	669 local and unnamed types as template arguments is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	670
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	671 C++11 noexcept
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	672 ^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	673
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	674 Use ``__has_feature(cxx_noexcept)`` or ``__has_extension(cxx_noexcept)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	675 determine if support for noexcept exception specifications is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	676
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	677 C++11 in-class non-static data member initialization
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	678 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	679
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	680 Use ``__has_feature(cxx_nonstatic_member_init)`` to determine whether in-class
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	681 initialization of non-static data members is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	682
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	683 C++11 ``nullptr``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	684 ^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	685
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	686 Use ``__has_feature(cxx_nullptr)`` or ``__has_extension(cxx_nullptr)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	687 determine if support for ``nullptr`` is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	688
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	689 C++11 ``override control``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	690 ^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	691
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	692 Use ``__has_feature(cxx_override_control)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	693 ``__has_extension(cxx_override_control)`` to determine if support for the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	694 override control keywords is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	695
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	696 C++11 reference-qualified functions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	697 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	698
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	699 Use ``__has_feature(cxx_reference_qualified_functions)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	700 ``__has_extension(cxx_reference_qualified_functions)`` to determine if support
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	701 for reference-qualified functions (e.g., member functions with ``&`` or ``&&``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	702 applied to ``*this``) is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	703
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	704 C++11 range-based ``for`` loop
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	705 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	706
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	707 Use ``__has_feature(cxx_range_for)`` or ``__has_extension(cxx_range_for)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	708 determine if support for the range-based for loop is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	709
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	710 C++11 raw string literals
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	711 ^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	712
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	713 Use ``__has_feature(cxx_raw_string_literals)`` to determine if support for raw
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	714 string literals (e.g., ``R"x(foo\bar)x"``) is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	715
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	716 C++11 rvalue references
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	717 ^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	718
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	719 Use ``__has_feature(cxx_rvalue_references)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	720 ``__has_extension(cxx_rvalue_references)`` to determine if support for rvalue
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	721 references is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	722
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	723 C++11 ``static_assert()``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	724 ^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	725
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	726 Use ``__has_feature(cxx_static_assert)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	727 ``__has_extension(cxx_static_assert)`` to determine if support for compile-time
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	728 assertions using ``static_assert`` is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	729
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	730 C++11 ``thread_local``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	731 ^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	732
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	733 Use ``__has_feature(cxx_thread_local)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	734 ``thread_local`` variables is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	735
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	736 C++11 type inference
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	737 ^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	738
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	739 Use ``__has_feature(cxx_auto_type)`` or ``__has_extension(cxx_auto_type)`` to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	740 determine C++11 type inference is supported using the ``auto`` specifier. If
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	741 this is disabled, ``auto`` will instead be a storage class specifier, as in C
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	742 or C++98.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	743
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	744 C++11 strongly typed enumerations
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	745 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	746
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	747 Use ``__has_feature(cxx_strong_enums)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	748 ``__has_extension(cxx_strong_enums)`` to determine if support for strongly
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	749 typed, scoped enumerations is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	750
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	751 C++11 trailing return type
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	752 ^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	753
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	754 Use ``__has_feature(cxx_trailing_return)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	755 ``__has_extension(cxx_trailing_return)`` to determine if support for the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	756 alternate function declaration syntax with trailing return type is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	757
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	758 C++11 Unicode string literals
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	759 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	760
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	761 Use ``__has_feature(cxx_unicode_literals)`` to determine if support for Unicode
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	762 string literals is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	763
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	764 C++11 unrestricted unions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	765 ^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	766
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	767 Use ``__has_feature(cxx_unrestricted_unions)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	768 unrestricted unions is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	769
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	770 C++11 user-defined literals
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	771 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	772
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	773 Use ``__has_feature(cxx_user_literals)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	774 user-defined literals is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	775
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	776 C++11 variadic templates
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	777 ^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	778
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	779 Use ``__has_feature(cxx_variadic_templates)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	780 ``__has_extension(cxx_variadic_templates)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	781 variadic templates is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	782
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	783 C++1y
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	784 -----
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	785
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	786 The features listed below are part of the committee draft for the C++1y
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	787 standard. As a result, all these features are enabled with the ``-std=c++1y``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	788 or ``-std=gnu++1y`` option when compiling C++ code.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	789
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	790 C++1y binary literals
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	791 ^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	792
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	793 Use ``__has_feature(cxx_binary_literals)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	794 ``__has_extension(cxx_binary_literals)`` to determine whether
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	795 binary literals (for instance, ``0b10010``) are recognized. Clang supports this
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	796 feature as an extension in all language modes.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	797
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	798 C++1y contextual conversions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	799 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	800
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	801 Use ``__has_feature(cxx_contextual_conversions)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	802 ``__has_extension(cxx_contextual_conversions)`` to determine if the C++1y rules
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	803 are used when performing an implicit conversion for an array bound in a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	804 new-expression, the operand of a delete-expression, an integral constant
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	805 expression, or a condition in a ``switch`` statement.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	806
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	807 C++1y decltype(auto)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	808 ^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	809
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	810 Use ``__has_feature(cxx_decltype_auto)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	811 ``__has_extension(cxx_decltype_auto)`` to determine if support
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	812 for the ``decltype(auto)`` placeholder type is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	813
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	814 C++1y default initializers for aggregates
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	815 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	816
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	817 Use ``__has_feature(cxx_aggregate_nsdmi)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	818 ``__has_extension(cxx_aggregate_nsdmi)`` to determine if support
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	819 for default initializers in aggregate members is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	820
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	821 C++1y digit separators
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	822 ^^^^^^^^^^^^^^^^^^^^^^
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	823
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	824 Use ``__cpp_digit_separators`` to determine if support for digit separators
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	825 using single quotes (for instance, ``10'000``) is enabled. At this time, there
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	826 is no corresponding ``__has_feature`` name
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	827
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	828 C++1y generalized lambda capture
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	829 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	830
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	831 Use ``__has_feature(cxx_init_captures)`` or
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	832 ``__has_extension(cxx_init_captures)`` to determine if support for
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	833 lambda captures with explicit initializers is enabled
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	834 (for instance, ``[n(0)] { return ++n; }``).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	835
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	836 C++1y generic lambdas
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	837 ^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	838
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	839 Use ``__has_feature(cxx_generic_lambdas)`` or
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	840 ``__has_extension(cxx_generic_lambdas)`` to determine if support for generic
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	841 (polymorphic) lambdas is enabled
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	842 (for instance, ``[] (auto x) { return x + 1; }``).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	843
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	844 C++1y relaxed constexpr
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	845 ^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	846
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	847 Use ``__has_feature(cxx_relaxed_constexpr)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	848 ``__has_extension(cxx_relaxed_constexpr)`` to determine if variable
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	849 declarations, local variable modification, and control flow constructs
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	850 are permitted in ``constexpr`` functions.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	851
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	852 C++1y return type deduction
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	853 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	854
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	855 Use ``__has_feature(cxx_return_type_deduction)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	856 ``__has_extension(cxx_return_type_deduction)`` to determine if support
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	857 for return type deduction for functions (using ``auto`` as a return type)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	858 is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	859
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	860 C++1y runtime-sized arrays
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	861 ^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	862
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	863 Use ``__has_feature(cxx_runtime_array)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	864 ``__has_extension(cxx_runtime_array)`` to determine if support
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	865 for arrays of runtime bound (a restricted form of variable-length arrays)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	866 is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	867 Clang's implementation of this feature is incomplete.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	868
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	869 C++1y variable templates
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	870 ^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	871
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	872 Use ``__has_feature(cxx_variable_templates)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	873 ``__has_extension(cxx_variable_templates)`` to determine if support for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	874 templated variable declarations is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	875
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	876 C11
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	877 ---
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	878
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	879 The features listed below are part of the C11 standard. As a result, all these
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	880 features are enabled with the ``-std=c11`` or ``-std=gnu11`` option when
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	881 compiling C code. Additionally, because these features are all
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	882 backward-compatible, they are available as extensions in all language modes.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	883
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	884 C11 alignment specifiers
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	885 ^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	886
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	887 Use ``__has_feature(c_alignas)`` or ``__has_extension(c_alignas)`` to determine
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	888 if support for alignment specifiers using ``_Alignas`` is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	889
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	890 Use ``__has_feature(c_alignof)`` or ``__has_extension(c_alignof)`` to determine
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	891 if support for the ``_Alignof`` keyword is enabled.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	892
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	893 C11 atomic operations
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	894 ^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	895
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	896 Use ``__has_feature(c_atomic)`` or ``__has_extension(c_atomic)`` to determine
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	897 if support for atomic types using ``_Atomic`` is enabled. Clang also provides
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	898 :ref:`a set of builtins <langext-__c11_atomic>` which can be used to implement
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	899 the ``<stdatomic.h>`` operations on ``_Atomic`` types. Use
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	900 ``__has_include(<stdatomic.h>)`` to determine if C11's ``<stdatomic.h>`` header
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	901 is available.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	902
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	903 Clang will use the system's ``<stdatomic.h>`` header when one is available, and
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	904 will otherwise use its own. When using its own, implementations of the atomic
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	905 operations are provided as macros. In the cases where C11 also requires a real
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	906 function, this header provides only the declaration of that function (along
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	907 with a shadowing macro implementation), and you must link to a library which
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	908 provides a definition of the function if you use it instead of the macro.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	909
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	910 C11 generic selections
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	911 ^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	912
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	913 Use ``__has_feature(c_generic_selections)`` or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	914 ``__has_extension(c_generic_selections)`` to determine if support for generic
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	915 selections is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	916
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	917 As an extension, the C11 generic selection expression is available in all
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	918 languages supported by Clang. The syntax is the same as that given in the C11
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	919 standard.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	920
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	921 In C, type compatibility is decided according to the rules given in the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	922 appropriate standard, but in C++, which lacks the type compatibility rules used
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	923 in C, types are considered compatible only if they are equivalent.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	924
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	925 C11 ``_Static_assert()``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	926 ^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	927
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	928 Use ``__has_feature(c_static_assert)`` or ``__has_extension(c_static_assert)``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	929 to determine if support for compile-time assertions using ``_Static_assert`` is
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	930 enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	931
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	932 C11 ``_Thread_local``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	933 ^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	934
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	935 Use ``__has_feature(c_thread_local)`` or ``__has_extension(c_thread_local)``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	936 to determine if support for ``_Thread_local`` variables is enabled.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	937
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	938 Modules
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	939 -------
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	940
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	941 Use ``__has_feature(modules)`` to determine if Modules have been enabled.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	942 For example, compiling code with ``-fmodules`` enables the use of Modules.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	943
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	944 More information could be found `here <http://clang.llvm.org/docs/Modules.html>`_.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	945
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	946 Checks for Type Trait Primitives
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	947 ================================
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	948
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	949 Type trait primitives are special builtin constant expressions that can be used
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	950 by the standard C++ library to facilitate or simplify the implementation of
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	951 user-facing type traits in the <type_traits> header.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	952
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	953 They are not intended to be used directly by user code because they are
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	954 implementation-defined and subject to change -- as such they're tied closely to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	955 the supported set of system headers, currently:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	956
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	957 * LLVM's own libc++
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	958 * GNU libstdc++
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	959 * The Microsoft standard C++ library
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	960
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	961 Clang supports the `GNU C++ type traits
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	962 <http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html>`_ and a subset of the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	963 `Microsoft Visual C++ Type traits
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	964 <http://msdn.microsoft.com/en-us/library/ms177194(v=VS.100).aspx>`_.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	965
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	966 Feature detection is supported only for some of the primitives at present. User
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	967 code should not use these checks because they bear no direct relation to the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	968 actual set of type traits supported by the C++ standard library.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	969
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	970 For type trait ``__X``, ``__has_extension(X)`` indicates the presence of the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	971 type trait primitive in the compiler. A simplistic usage example as might be
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	972 seen in standard C++ headers follows:
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	973
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	974 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	975
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	976 #if __has_extension(is_convertible_to)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	977 template<typename From, typename To>
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	978 struct is_convertible_to {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	979 static const bool value = __is_convertible_to(From, To);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	980 };
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	981 #else
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	982 // Emulate type trait for compatibility with other compilers.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	983 #endif
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	984
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	985 The following type trait primitives are supported by Clang:
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	986
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	987 * ``__has_nothrow_assign`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	988 * ``__has_nothrow_copy`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	989 * ``__has_nothrow_constructor`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	990 * ``__has_trivial_assign`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	991 * ``__has_trivial_copy`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	992 * ``__has_trivial_constructor`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	993 * ``__has_trivial_destructor`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	994 * ``__has_virtual_destructor`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	995 * ``__is_abstract`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	996 * ``__is_base_of`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	997 * ``__is_class`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	998 * ``__is_convertible_to`` (Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	999 * ``__is_empty`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1000 * ``__is_enum`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1001 * ``__is_interface_class`` (Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1002 * ``__is_pod`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1003 * ``__is_polymorphic`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1004 * ``__is_union`` (GNU, Microsoft)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1005 * ``__is_literal(type)``: Determines whether the given type is a literal type
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1006 * ``__is_final``: Determines whether the given type is declared with a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1007 ``final`` class-virt-specifier.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1008 * ``__underlying_type(type)``: Retrieves the underlying type for a given
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1009 ``enum`` type. This trait is required to implement the C++11 standard
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1010 library.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1011 * ``__is_trivially_assignable(totype, fromtype)``: Determines whether a value
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1012 of type ``totype`` can be assigned to from a value of type ``fromtype`` such
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1013 that no non-trivial functions are called as part of that assignment. This
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1014 trait is required to implement the C++11 standard library.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1015 * ``__is_trivially_constructible(type, argtypes...)``: Determines whether a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1016 value of type ``type`` can be direct-initialized with arguments of types
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1017 ``argtypes...`` such that no non-trivial functions are called as part of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1018 that initialization. This trait is required to implement the C++11 standard
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1019 library.
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1020 * ``__is_destructible`` (MSVC 2013): partially implemented
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1021 * ``__is_nothrow_destructible`` (MSVC 2013): partially implemented
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1022 * ``__is_nothrow_assignable`` (MSVC 2013, clang)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1023 * ``__is_constructible`` (MSVC 2013, clang)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1024 * ``__is_nothrow_constructible`` (MSVC 2013, clang)
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1025
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1026 Blocks
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1027 ======
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1028
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1029 The syntax and high level language feature description is in
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1030 :doc:`BlockLanguageSpec<BlockLanguageSpec>`. Implementation and ABI details for
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1031 the clang implementation are in :doc:`Block-ABI-Apple<Block-ABI-Apple>`.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1032
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1033 Query for this feature with ``__has_extension(blocks)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1034
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1035 Objective-C Features
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1036 ====================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1037
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1038 Related result types
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1039 --------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1040
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1041 According to Cocoa conventions, Objective-C methods with certain names
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1042 ("``init``", "``alloc``", etc.) always return objects that are an instance of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1043 the receiving class's type. Such methods are said to have a "related result
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1044 type", meaning that a message send to one of these methods will have the same
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1045 static type as an instance of the receiver class. For example, given the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1046 following classes:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1047
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1048 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1049
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1050 @interface NSObject
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1051 + (id)alloc;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1052 - (id)init;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1053 @end
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1054
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1055 @interface NSArray : NSObject
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1056 @end
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1057
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1058 and this common initialization pattern
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1059
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1060 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1061
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1062 NSArray *array = [[NSArray alloc] init];
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1063
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1064 the type of the expression ``[NSArray alloc]`` is ``NSArray*`` because
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1065 ``alloc`` implicitly has a related result type. Similarly, the type of the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1066 expression ``[[NSArray alloc] init]`` is ``NSArray*``, since ``init`` has a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1067 related result type and its receiver is known to have the type ``NSArray *``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1068 If neither ``alloc`` nor ``init`` had a related result type, the expressions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1069 would have had type ``id``, as declared in the method signature.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1070
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1071 A method with a related result type can be declared by using the type
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1072 ``instancetype`` as its result type. ``instancetype`` is a contextual keyword
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1073 that is only permitted in the result type of an Objective-C method, e.g.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1074
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1075 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1076
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1077 @interface A
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1078 + (instancetype)constructAnA;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1079 @end
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1080
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1081 The related result type can also be inferred for some methods. To determine
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1082 whether a method has an inferred related result type, the first word in the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1083 camel-case selector (e.g., "``init``" in "``initWithObjects``") is considered,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1084 and the method will have a related result type if its return type is compatible
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1085 with the type of its class and if:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1086
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1087 * the first word is "``alloc``" or "``new``", and the method is a class method,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1088 or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1089
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1090 * the first word is "``autorelease``", "``init``", "``retain``", or "``self``",
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1091 and the method is an instance method.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1092
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1093 If a method with a related result type is overridden by a subclass method, the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1094 subclass method must also return a type that is compatible with the subclass
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1095 type. For example:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1096
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1097 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1098
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1099 @interface NSString : NSObject
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1100 - (NSUnrelated *)init; // incorrect usage: NSUnrelated is not NSString or a superclass of NSString
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1101 @end
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1102
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1103 Related result types only affect the type of a message send or property access
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1104 via the given method. In all other respects, a method with a related result
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1105 type is treated the same way as method that returns ``id``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1106
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1107 Use ``__has_feature(objc_instancetype)`` to determine whether the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1108 ``instancetype`` contextual keyword is available.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1109
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1110 Automatic reference counting
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1111 ----------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1112
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1113 Clang provides support for :doc:`automated reference counting
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1114 <AutomaticReferenceCounting>` in Objective-C, which eliminates the need
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1115 for manual ``retain``/``release``/``autorelease`` message sends. There are two
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1116 feature macros associated with automatic reference counting:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1117 ``__has_feature(objc_arc)`` indicates the availability of automated reference
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1118 counting in general, while ``__has_feature(objc_arc_weak)`` indicates that
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1119 automated reference counting also includes support for ``__weak`` pointers to
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1120 Objective-C objects.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1121
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1122 .. _objc-fixed-enum:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1123
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1124 Enumerations with a fixed underlying type
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1125 -----------------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1126
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1127 Clang provides support for C++11 enumerations with a fixed underlying type
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1128 within Objective-C. For example, one can write an enumeration type as:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1129
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1130 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1131
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1132 typedef enum : unsigned char { Red, Green, Blue } Color;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1133
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1134 This specifies that the underlying type, which is used to store the enumeration
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1135 value, is ``unsigned char``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1136
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1137 Use ``__has_feature(objc_fixed_enum)`` to determine whether support for fixed
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1138 underlying types is available in Objective-C.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1139
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1140 Interoperability with C++11 lambdas
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1141 -----------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1142
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1143 Clang provides interoperability between C++11 lambdas and blocks-based APIs, by
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1144 permitting a lambda to be implicitly converted to a block pointer with the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1145 corresponding signature. For example, consider an API such as ``NSArray``'s
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1146 array-sorting method:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1147
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1148 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1149
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1150 - (NSArray *)sortedArrayUsingComparator:(NSComparator)cmptr;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1151
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1152 ``NSComparator`` is simply a typedef for the block pointer ``NSComparisonResult
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1153 (^)(id, id)``, and parameters of this type are generally provided with block
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1154 literals as arguments. However, one can also use a C++11 lambda so long as it
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1155 provides the same signature (in this case, accepting two parameters of type
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1156 ``id`` and returning an ``NSComparisonResult``):
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1157
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1158 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1159
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1160 NSArray *array = @[@"string 1", @"string 21", @"string 12", @"String 11",
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1161 @"String 02"];
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1162 const NSStringCompareOptions comparisonOptions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1163 = NSCaseInsensitiveSearch \| NSNumericSearch \|
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1164 NSWidthInsensitiveSearch \| NSForcedOrderingSearch;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1165 NSLocale *currentLocale = [NSLocale currentLocale];
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1166 NSArray *sorted
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1167 = [array sortedArrayUsingComparator:[=](id s1, id s2) -> NSComparisonResult {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1168 NSRange string1Range = NSMakeRange(0, [s1 length]);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1169 return [s1 compare:s2 options:comparisonOptions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1170 range:string1Range locale:currentLocale];
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1171 }];
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1172 NSLog(@"sorted: %@", sorted);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1173
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1174 This code relies on an implicit conversion from the type of the lambda
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1175 expression (an unnamed, local class type called the closure type) to the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1176 corresponding block pointer type. The conversion itself is expressed by a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1177 conversion operator in that closure type that produces a block pointer with the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1178 same signature as the lambda itself, e.g.,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1179
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1180 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1181
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1182 operator NSComparisonResult (^)(id, id)() const;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1183
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1184 This conversion function returns a new block that simply forwards the two
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1185 parameters to the lambda object (which it captures by copy), then returns the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1186 result. The returned block is first copied (with ``Block_copy``) and then
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1187 autoreleased. As an optimization, if a lambda expression is immediately
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1188 converted to a block pointer (as in the first example, above), then the block
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1189 is not copied and autoreleased: rather, it is given the same lifetime as a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1190 block literal written at that point in the program, which avoids the overhead
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1191 of copying a block to the heap in the common case.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1192
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1193 The conversion from a lambda to a block pointer is only available in
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1194 Objective-C++, and not in C++ with blocks, due to its use of Objective-C memory
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1195 management (autorelease).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1196
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1197 Object Literals and Subscripting
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1198 --------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1199
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1200 Clang provides support for :doc:`Object Literals and Subscripting
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1201 <ObjectiveCLiterals>` in Objective-C, which simplifies common Objective-C
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1202 programming patterns, makes programs more concise, and improves the safety of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1203 container creation. There are several feature macros associated with object
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1204 literals and subscripting: ``__has_feature(objc_array_literals)`` tests the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1205 availability of array literals; ``__has_feature(objc_dictionary_literals)``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1206 tests the availability of dictionary literals;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1207 ``__has_feature(objc_subscripting)`` tests the availability of object
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1208 subscripting.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1209
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1210 Objective-C Autosynthesis of Properties
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1211 ---------------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1212
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1213 Clang provides support for autosynthesis of declared properties. Using this
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1214 feature, clang provides default synthesis of those properties not declared
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1215 @dynamic and not having user provided backing getter and setter methods.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1216 ``__has_feature(objc_default_synthesize_properties)`` checks for availability
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1217 of this feature in version of clang being used.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1218
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1219 .. _langext-objc-retain-release:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1220
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1221 Objective-C retaining behavior attributes
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1222 -----------------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1223
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1224 In Objective-C, functions and methods are generally assumed to follow the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1225 `Cocoa Memory Management
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1226 <http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/MemoryMgmt/Articles/mmRules.html>`_
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1227 conventions for ownership of object arguments and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1228 return values. However, there are exceptions, and so Clang provides attributes
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1229 to allow these exceptions to be documented. This are used by ARC and the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1230 `static analyzer <http://clang-analyzer.llvm.org>`_ Some exceptions may be
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1231 better described using the ``objc_method_family`` attribute instead.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1232
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1233 Usage: The ``ns_returns_retained``, ``ns_returns_not_retained``,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1234 ``ns_returns_autoreleased``, ``cf_returns_retained``, and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1235 ``cf_returns_not_retained`` attributes can be placed on methods and functions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1236 that return Objective-C or CoreFoundation objects. They are commonly placed at
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1237 the end of a function prototype or method declaration:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1238
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1239 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1240
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1241 id foo() __attribute__((ns_returns_retained));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1242
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1243 - (NSString *)bar:(int)x __attribute__((ns_returns_retained));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1244
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1245 The ``*_returns_retained`` attributes specify that the returned object has a +1
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1246 retain count. The ``*_returns_not_retained`` attributes specify that the return
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1247 object has a +0 retain count, even if the normal convention for its selector
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1248 would be +1. ``ns_returns_autoreleased`` specifies that the returned object is
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1249 +0, but is guaranteed to live at least as long as the next flush of an
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1250 autorelease pool.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1251
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1252 Usage: The ``ns_consumed`` and ``cf_consumed`` attributes can be placed on
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1253 an parameter declaration; they specify that the argument is expected to have a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1254 +1 retain count, which will be balanced in some way by the function or method.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1255 The ``ns_consumes_self`` attribute can only be placed on an Objective-C
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1256 method; it specifies that the method expects its ``self`` parameter to have a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1257 +1 retain count, which it will balance in some way.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1258
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1259 .. code-block:: objc
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1260
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1261 void foo(__attribute__((ns_consumed)) NSString *string);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1262
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1263 - (void) bar __attribute__((ns_consumes_self));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1264 - (void) baz:(id) __attribute__((ns_consumed)) x;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1265
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1266 Further examples of these attributes are available in the static analyzer's `list of annotations for analysis
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1267 <http://clang-analyzer.llvm.org/annotations.html#cocoa_mem>`_.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1268
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1269 Query for these features with ``__has_attribute(ns_consumed)``,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1270 ``__has_attribute(ns_returns_retained)``, etc.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1271
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1272
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1273 Objective-C++ ABI: protocol-qualifier mangling of parameters
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1274 ------------------------------------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1275
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1276 Starting with LLVM 3.4, Clang produces a new mangling for parameters whose
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1277 type is a qualified-``id`` (e.g., ``id<Foo>``). This mangling allows such
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1278 parameters to be differentiated from those with the regular unqualified ``id``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1279 type.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1280
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1281 This was a non-backward compatible mangling change to the ABI. This change
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1282 allows proper overloading, and also prevents mangling conflicts with template
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1283 parameters of protocol-qualified type.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1284
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1285 Query the presence of this new mangling with
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1286 ``__has_feature(objc_protocol_qualifier_mangling)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1287
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1288 .. _langext-overloading:
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1289
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1290 Initializer lists for complex numbers in C
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1291 ==========================================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1292
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1293 clang supports an extension which allows the following in C:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1294
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1295 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1296
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1297 #include <math.h>
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1298 #include <complex.h>
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1299 complex float x = { 1.0f, INFINITY }; // Init to (1, Inf)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1300
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1301 This construct is useful because there is no way to separately initialize the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1302 real and imaginary parts of a complex variable in standard C, given that clang
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1303 does not support ``_Imaginary``. (Clang also supports the ``__real__`` and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1304 ``__imag__`` extensions from gcc, which help in some cases, but are not usable
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1305 in static initializers.)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1306
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1307 Note that this extension does not allow eliding the braces; the meaning of the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1308 following two lines is different:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1309
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1310 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1311
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1312 complex float x[] = { { 1.0f, 1.0f } }; // [0] = (1, 1)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1313 complex float x[] = { 1.0f, 1.0f }; // [0] = (1, 0), [1] = (1, 0)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1314
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1315 This extension also works in C++ mode, as far as that goes, but does not apply
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1316 to the C++ ``std::complex``. (In C++11, list initialization allows the same
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1317 syntax to be used with ``std::complex`` with the same meaning.)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1318
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1319 Builtin Functions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1320 =================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1321
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1322 Clang supports a number of builtin library functions with the same syntax as
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1323 GCC, including things like ``__builtin_nan``, ``__builtin_constant_p``,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1324 ``__builtin_choose_expr``, ``__builtin_types_compatible_p``,
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1325 ``__builtin_assume_aligned``, ``__sync_fetch_and_add``, etc. In addition to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1326 the GCC builtins, Clang supports a number of builtins that GCC does not, which
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1327 are listed here.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1328
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1329 Please note that Clang does not and will not support all of the GCC builtins
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1330 for vector operations. Instead of using builtins, you should use the functions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1331 defined in target-specific header files like ``<xmmintrin.h>``, which define
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1332 portable wrappers for these. Many of the Clang versions of these functions are
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1333 implemented directly in terms of :ref:`extended vector support
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1334 <langext-vectors>` instead of builtins, in order to reduce the number of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1335 builtins that we need to implement.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1336
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1337 ``__builtin_assume``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1338 ------------------------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1339
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1340 ``__builtin_assume`` is used to provide the optimizer with a boolean
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1341 invariant that is defined to be true.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1342
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1343 Syntax:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1344
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1345 .. code-block:: c++
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1346
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1347 __builtin_assume(bool)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1348
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1349 Example of Use:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1350
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1351 .. code-block:: c++
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1352
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1353 int foo(int x) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1354 __builtin_assume(x != 0);
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1355
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1356 // The optimizer may short-circuit this check using the invariant.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1357 if (x == 0)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1358 return do_something();
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1359
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1360 return do_something_else();
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1361 }
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1362
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1363 Description:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1364
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1365 The boolean argument to this function is defined to be true. The optimizer may
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1366 analyze the form of the expression provided as the argument and deduce from
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1367 that information used to optimize the program. If the condition is violated
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1368 during execution, the behavior is undefined. The argument itself is never
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1369 evaluated, so any side effects of the expression will be discarded.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1370
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1371 Query for this feature with ``__has_builtin(__builtin_assume)``.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1372
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1373 ``__builtin_readcyclecounter``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1374 ------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1375
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1376 ``__builtin_readcyclecounter`` is used to access the cycle counter register (or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1377 a similar low-latency, high-accuracy clock) on those targets that support it.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1378
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1379 Syntax:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1380
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1381 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1382
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1383 __builtin_readcyclecounter()
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1384
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1385 Example of Use:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1386
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1387 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1388
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1389 unsigned long long t0 = __builtin_readcyclecounter();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1390 do_something();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1391 unsigned long long t1 = __builtin_readcyclecounter();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1392 unsigned long long cycles_to_do_something = t1 - t0; // assuming no overflow
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1393
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1394 Description:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1395
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1396 The ``__builtin_readcyclecounter()`` builtin returns the cycle counter value,
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1397 which may be either global or process/thread-specific depending on the target.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1398 As the backing counters often overflow quickly (on the order of seconds) this
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1399 should only be used for timing small intervals. When not supported by the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1400 target, the return value is always zero. This builtin takes no arguments and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1401 produces an unsigned long long result.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1402
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1403 Query for this feature with ``__has_builtin(__builtin_readcyclecounter)``. Note
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1404 that even if present, its use may depend on run-time privilege or other OS
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1405 controlled state.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1406
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1407 .. _langext-__builtin_shufflevector:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1408
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1409 ``__builtin_shufflevector``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1410 ---------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1411
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1412 ``__builtin_shufflevector`` is used to express generic vector
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1413 permutation/shuffle/swizzle operations. This builtin is also very important
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1414 for the implementation of various target-specific header files like
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1415 ``<xmmintrin.h>``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1416
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1417 Syntax:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1418
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1419 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1420
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1421 __builtin_shufflevector(vec1, vec2, index1, index2, ...)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1422
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1423 Examples:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1424
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1425 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1426
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1427 // identity operation - return 4-element vector v1.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1428 __builtin_shufflevector(v1, v1, 0, 1, 2, 3)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1429
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1430 // "Splat" element 0 of V1 into a 4-element result.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1431 __builtin_shufflevector(V1, V1, 0, 0, 0, 0)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1432
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1433 // Reverse 4-element vector V1.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1434 __builtin_shufflevector(V1, V1, 3, 2, 1, 0)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1435
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1436 // Concatenate every other element of 4-element vectors V1 and V2.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1437 __builtin_shufflevector(V1, V2, 0, 2, 4, 6)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1438
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1439 // Concatenate every other element of 8-element vectors V1 and V2.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1440 __builtin_shufflevector(V1, V2, 0, 2, 4, 6, 8, 10, 12, 14)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1441
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1442 // Shuffle v1 with some elements being undefined
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1443 __builtin_shufflevector(v1, v1, 3, -1, 1, -1)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1444
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1445 Description:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1446
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1447 The first two arguments to ``__builtin_shufflevector`` are vectors that have
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1448 the same element type. The remaining arguments are a list of integers that
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1449 specify the elements indices of the first two vectors that should be extracted
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1450 and returned in a new vector. These element indices are numbered sequentially
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1451 starting with the first vector, continuing into the second vector. Thus, if
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1452 ``vec1`` is a 4-element vector, index 5 would refer to the second element of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1453 ``vec2``. An index of -1 can be used to indicate that the corresponding element
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1454 in the returned vector is a don't care and can be optimized by the backend.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1455
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1456 The result of ``__builtin_shufflevector`` is a vector with the same element
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1457 type as ``vec1``/``vec2`` but that has an element count equal to the number of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1458 indices specified.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1459
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1460 Query for this feature with ``__has_builtin(__builtin_shufflevector)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1461
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1462 .. _langext-__builtin_convertvector:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1463
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1464 ``__builtin_convertvector``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1465 ---------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1466
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1467 ``__builtin_convertvector`` is used to express generic vector
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1468 type-conversion operations. The input vector and the output vector
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1469 type must have the same number of elements.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1470
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1471 Syntax:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1472
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1473 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1474
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1475 __builtin_convertvector(src_vec, dst_vec_type)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1476
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1477 Examples:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1478
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1479 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1480
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1481 typedef double vector4double __attribute__((__vector_size__(32)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1482 typedef float vector4float __attribute__((__vector_size__(16)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1483 typedef short vector4short __attribute__((__vector_size__(8)));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1484 vector4float vf; vector4short vs;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1485
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1486 // convert from a vector of 4 floats to a vector of 4 doubles.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1487 __builtin_convertvector(vf, vector4double)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1488 // equivalent to:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1489 (vector4double) { (double) vf[0], (double) vf[1], (double) vf[2], (double) vf[3] }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1490
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1491 // convert from a vector of 4 shorts to a vector of 4 floats.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1492 __builtin_convertvector(vs, vector4float)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1493 // equivalent to:
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1494 (vector4float) { (float) vs[0], (float) vs[1], (float) vs[2], (float) vs[3] }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1495
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1496 Description:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1497
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1498 The first argument to ``__builtin_convertvector`` is a vector, and the second
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1499 argument is a vector type with the same number of elements as the first
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1500 argument.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1501
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1502 The result of ``__builtin_convertvector`` is a vector with the same element
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1503 type as the second argument, with a value defined in terms of the action of a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1504 C-style cast applied to each element of the first argument.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1505
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1506 Query for this feature with ``__has_builtin(__builtin_convertvector)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1507
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1508 ``__builtin_unreachable``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1509 -------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1510
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1511 ``__builtin_unreachable`` is used to indicate that a specific point in the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1512 program cannot be reached, even if the compiler might otherwise think it can.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1513 This is useful to improve optimization and eliminates certain warnings. For
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1514 example, without the ``__builtin_unreachable`` in the example below, the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1515 compiler assumes that the inline asm can fall through and prints a "function
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1516 declared '``noreturn``' should not return" warning.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1517
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1518 Syntax:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1519
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1520 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1521
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1522 __builtin_unreachable()
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1523
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1524 Example of use:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1525
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1526 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1527
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1528 void myabort(void) __attribute__((noreturn));
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1529 void myabort(void) {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1530 asm("int3");
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1531 __builtin_unreachable();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1532 }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1533
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1534 Description:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1535
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1536 The ``__builtin_unreachable()`` builtin has completely undefined behavior.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1537 Since it has undefined behavior, it is a statement that it is never reached and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1538 the optimizer can take advantage of this to produce better code. This builtin
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1539 takes no arguments and produces a void result.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1540
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1541 Query for this feature with ``__has_builtin(__builtin_unreachable)``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1542
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1543 ``__builtin_unpredictable``
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1544 ---------------------------
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1545
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1546 ``__builtin_unpredictable`` is used to indicate that a branch condition is
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1547 unpredictable by hardware mechanisms such as branch prediction logic.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1548
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1549 Syntax:
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1550
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1551 .. code-block:: c++
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1552
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1553 __builtin_unpredictable(long long)
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1554
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1555 Example of use:
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1556
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1557 .. code-block:: c++
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1558
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1559 if (__builtin_unpredictable(x > 0)) {
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1560 foo();
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1561 }
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1562
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1563 Description:
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1564
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1565 The ``__builtin_unpredictable()`` builtin is expected to be used with control
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1566 flow conditions such as in ``if`` and ``switch`` statements.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1567
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1568 Query for this feature with ``__has_builtin(__builtin_unpredictable)``.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1569
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1570 ``__sync_swap``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1571 ---------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1572
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1573 ``__sync_swap`` is used to atomically swap integers or pointers in memory.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1574
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1575 Syntax:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1576
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1577 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1578
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1579 type __sync_swap(type *ptr, type value, ...)
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1580
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1581 Example of Use:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1582
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1583 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1584
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1585 int old_value = __sync_swap(&value, new_value);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1586
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1587 Description:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1588
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1589 The ``__sync_swap()`` builtin extends the existing ``__sync_*()`` family of
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1590 atomic intrinsics to allow code to atomically swap the current value with the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1591 new value. More importantly, it helps developers write more efficient and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1592 correct code by avoiding expensive loops around
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1593 ``__sync_bool_compare_and_swap()`` or relying on the platform specific
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1594 implementation details of ``__sync_lock_test_and_set()``. The
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1595 ``__sync_swap()`` builtin is a full barrier.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1596
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1597 ``__builtin_addressof``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1598 -----------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1599
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1600 ``__builtin_addressof`` performs the functionality of the built-in ``&``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1601 operator, ignoring any ``operator&`` overload. This is useful in constant
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1602 expressions in C++11, where there is no other way to take the address of an
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1603 object that overloads ``operator&``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1604
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1605 Example of use:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1606
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1607 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1608
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1609 template<typename T> constexpr T *addressof(T &value) {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1610 return __builtin_addressof(value);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1611 }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1612
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1613 ``__builtin_operator_new`` and ``__builtin_operator_delete``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1614 ------------------------------------------------------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1615
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1616 ``__builtin_operator_new`` allocates memory just like a non-placement non-class
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1617 new-expression. This is exactly like directly calling the normal
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1618 non-placement ``::operator new``, except that it allows certain optimizations
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1619 that the C++ standard does not permit for a direct function call to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1620 ``::operator new`` (in particular, removing ``new`` / ``delete`` pairs and
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1621 merging allocations).
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1622
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1623 Likewise, ``__builtin_operator_delete`` deallocates memory just like a
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1624 non-class delete-expression, and is exactly like directly calling the normal
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1625 ``::operator delete``, except that it permits optimizations. Only the unsized
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1626 form of ``__builtin_operator_delete`` is currently available.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1627
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1628 These builtins are intended for use in the implementation of ``std::allocator``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1629 and other similar allocation libraries, and are only available in C++.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1630
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1631 Multiprecision Arithmetic Builtins
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1632 ----------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1633
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1634 Clang provides a set of builtins which expose multiprecision arithmetic in a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1635 manner amenable to C. They all have the following form:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1636
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1637 .. code-block:: c
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1638
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1639 unsigned x = ..., y = ..., carryin = ..., carryout;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1640 unsigned sum = __builtin_addc(x, y, carryin, &carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1641
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1642 Thus one can form a multiprecision addition chain in the following manner:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1643
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1644 .. code-block:: c
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1645
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1646 unsigned x, y, *z, carryin=0, carryout;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1647 z[0] = __builtin_addc(x[0], y[0], carryin, &carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1648 carryin = carryout;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1649 z[1] = __builtin_addc(x[1], y[1], carryin, &carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1650 carryin = carryout;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1651 z[2] = __builtin_addc(x[2], y[2], carryin, &carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1652 carryin = carryout;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1653 z[3] = __builtin_addc(x[3], y[3], carryin, &carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1654
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1655 The complete list of builtins are:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1656
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1657 .. code-block:: c
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1658
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1659 unsigned char __builtin_addcb (unsigned char x, unsigned char y, unsigned char carryin, unsigned char *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1660 unsigned short __builtin_addcs (unsigned short x, unsigned short y, unsigned short carryin, unsigned short *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1661 unsigned __builtin_addc (unsigned x, unsigned y, unsigned carryin, unsigned *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1662 unsigned long __builtin_addcl (unsigned long x, unsigned long y, unsigned long carryin, unsigned long *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1663 unsigned long long __builtin_addcll(unsigned long long x, unsigned long long y, unsigned long long carryin, unsigned long long *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1664 unsigned char __builtin_subcb (unsigned char x, unsigned char y, unsigned char carryin, unsigned char *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1665 unsigned short __builtin_subcs (unsigned short x, unsigned short y, unsigned short carryin, unsigned short *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1666 unsigned __builtin_subc (unsigned x, unsigned y, unsigned carryin, unsigned *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1667 unsigned long __builtin_subcl (unsigned long x, unsigned long y, unsigned long carryin, unsigned long *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1668 unsigned long long __builtin_subcll(unsigned long long x, unsigned long long y, unsigned long long carryin, unsigned long long *carryout);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1669
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1670 Checked Arithmetic Builtins
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1671 ---------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1672
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1673 Clang provides a set of builtins that implement checked arithmetic for security
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1674 critical applications in a manner that is fast and easily expressable in C. As
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1675 an example of their usage:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1676
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1677 .. code-block:: c
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1678
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1679 errorcode_t security_critical_application(...) {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1680 unsigned x, y, result;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1681 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1682 if (__builtin_umul_overflow(x, y, &result))
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1683 return kErrorCodeHackers;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1684 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1685 use_multiply(result);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1686 ...
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1687 }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1688
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1689 A complete enumeration of the builtins are:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1690
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1691 .. code-block:: c
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1692
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1693 bool __builtin_uadd_overflow (unsigned x, unsigned y, unsigned *sum);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1694 bool __builtin_uaddl_overflow (unsigned long x, unsigned long y, unsigned long *sum);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1695 bool __builtin_uaddll_overflow(unsigned long long x, unsigned long long y, unsigned long long *sum);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1696 bool __builtin_usub_overflow (unsigned x, unsigned y, unsigned *diff);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1697 bool __builtin_usubl_overflow (unsigned long x, unsigned long y, unsigned long *diff);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1698 bool __builtin_usubll_overflow(unsigned long long x, unsigned long long y, unsigned long long *diff);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1699 bool __builtin_umul_overflow (unsigned x, unsigned y, unsigned *prod);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1700 bool __builtin_umull_overflow (unsigned long x, unsigned long y, unsigned long *prod);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1701 bool __builtin_umulll_overflow(unsigned long long x, unsigned long long y, unsigned long long *prod);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1702 bool __builtin_sadd_overflow (int x, int y, int *sum);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1703 bool __builtin_saddl_overflow (long x, long y, long *sum);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1704 bool __builtin_saddll_overflow(long long x, long long y, long long *sum);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1705 bool __builtin_ssub_overflow (int x, int y, int *diff);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1706 bool __builtin_ssubl_overflow (long x, long y, long *diff);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1707 bool __builtin_ssubll_overflow(long long x, long long y, long long *diff);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1708 bool __builtin_smul_overflow (int x, int y, int *prod);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1709 bool __builtin_smull_overflow (long x, long y, long *prod);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1710 bool __builtin_smulll_overflow(long long x, long long y, long long *prod);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1711
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1712
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1713 .. _langext-__c11_atomic:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1714
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1715 __c11_atomic builtins
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1716 ---------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1717
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1718 Clang provides a set of builtins which are intended to be used to implement
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1719 C11's ``<stdatomic.h>`` header. These builtins provide the semantics of the
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1720 ``_explicit`` form of the corresponding C11 operation, and are named with a
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1721 ``__c11_`` prefix. The supported operations, and the differences from
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1722 the corresponding C11 operations, are:
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1723
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1724 * ``__c11_atomic_init``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1725 * ``__c11_atomic_thread_fence``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1726 * ``__c11_atomic_signal_fence``
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1727 * ``__c11_atomic_is_lock_free`` (The argument is the size of the
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1728 ``_Atomic(...)`` object, instead of its address)
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1729 * ``__c11_atomic_store``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1730 * ``__c11_atomic_load``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1731 * ``__c11_atomic_exchange``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1732 * ``__c11_atomic_compare_exchange_strong``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1733 * ``__c11_atomic_compare_exchange_weak``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1734 * ``__c11_atomic_fetch_add``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1735 * ``__c11_atomic_fetch_sub``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1736 * ``__c11_atomic_fetch_and``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1737 * ``__c11_atomic_fetch_or``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1738 * ``__c11_atomic_fetch_xor``
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1739
83 60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1740 The macros ``__ATOMIC_RELAXED``, ``__ATOMIC_CONSUME``, ``__ATOMIC_ACQUIRE``,
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1741 ``__ATOMIC_RELEASE``, ``__ATOMIC_ACQ_REL``, and ``__ATOMIC_SEQ_CST`` are
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1742 provided, with values corresponding to the enumerators of C11's
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1743 ``memory_order`` enumeration.
60c9769439b8 LLVM 3.7 Tatsuki IHA <e125716@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	1744
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1745 (Note that Clang additionally provides GCC-compatible ``__atomic_*``
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1746 builtins)
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1747
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1748 Low-level ARM exclusive memory builtins
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1749 ---------------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1750
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1751 Clang provides overloaded builtins giving direct access to the three key ARM
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1752 instructions for implementing atomic operations.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1753
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1754 .. code-block:: c
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1755
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1756 T __builtin_arm_ldrex(const volatile T *addr);
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1757 T __builtin_arm_ldaex(const volatile T *addr);
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1758 int __builtin_arm_strex(T val, volatile T *addr);
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1759 int __builtin_arm_stlex(T val, volatile T *addr);
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1760 void __builtin_arm_clrex(void);
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1761
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1762 The types ``T`` currently supported are:
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1763
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1764 * Integer types with width at most 64 bits (or 128 bits on AArch64).
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1765 * Floating-point types
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1766 * Pointer types.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1767
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1768 Note that the compiler does not guarantee it will not insert stores which clear
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1769 the exclusive monitor in between an ``ldrex`` type operation and its paired
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1770 ``strex``. In practice this is only usually a risk when the extra store is on
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1771 the same cache line as the variable being modified and Clang will only insert
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1772 stack stores on its own, so it is best not to use these operations on variables
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1773 with automatic storage duration.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1774
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1775 Also, loads and stores may be implicit in code written between the ``ldrex`` and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1776 ``strex``. Clang will not necessarily mitigate the effects of these either, so
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1777 care should be exercised.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1778
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1779 For these reasons the higher level atomic primitives should be preferred where
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1780 possible.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1781
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1782 Non-temporal load/store builtins
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1783 --------------------------------
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1784
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1785 Clang provides overloaded builtins allowing generation of non-temporal memory
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1786 accesses.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1787
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1788 .. code-block:: c
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1789
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1790 T __builtin_nontemporal_load(T *addr);
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1791 void __builtin_nontemporal_store(T value, T *addr);
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1792
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1793 The types ``T`` currently supported are:
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1794
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1795 * Integer types.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1796 * Floating-point types.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1797 * Vector types.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1798
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1799 Note that the compiler does not guarantee that non-temporal loads or stores
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1800 will be used.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1801
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1802 Non-standard C++11 Attributes
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1803 =============================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1804
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1805 Clang's non-standard C++11 attributes live in the ``clang`` attribute
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1806 namespace.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1807
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1808 Clang supports GCC's ``gnu`` attribute namespace. All GCC attributes which
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1809 are accepted with the ``__attribute__((foo))`` syntax are also accepted as
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1810 ``[[gnu::foo]]``. This only extends to attributes which are specified by GCC
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1811 (see the list of `GCC function attributes
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1812 <http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>`_, `GCC variable
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1813 attributes <http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html>`_, and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1814 `GCC type attributes
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1815 <http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html>`_). As with the GCC
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1816 implementation, these attributes must appertain to the declarator-id in a
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1817 declaration, which means they must go either at the start of the declaration or
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1818 immediately after the name being declared.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1819
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1820 For example, this applies the GNU ``unused`` attribute to ``a`` and ``f``, and
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1821 also applies the GNU ``noreturn`` attribute to ``f``.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1822
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1823 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1824
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1825 [[gnu::unused]] int a, f [[gnu::noreturn]] ();
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1826
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1827 Target-Specific Extensions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1828 ==========================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1829
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1830 Clang supports some language features conditionally on some targets.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1831
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1832 ARM/AArch64 Language Extensions
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1833 -------------------------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1834
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1835 Memory Barrier Intrinsics
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1836 ^^^^^^^^^^^^^^^^^^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1837 Clang implements the ``__dmb``, ``__dsb`` and ``__isb`` intrinsics as defined
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1838 in the `ARM C Language Extensions Release 2.0
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1839 <http://infocenter.arm.com/help/topic/com.arm.doc.ihi0053c/IHI0053C_acle_2_0.pdf>`_.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1840 Note that these intrinsics are implemented as motion barriers that block
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1841 reordering of memory accesses and side effect instructions. Other instructions
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1842 like simple arithmatic may be reordered around the intrinsic. If you expect to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1843 have no reordering at all, use inline assembly instead.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1844
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1845 X86/X86-64 Language Extensions
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1846 ------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1847
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1848 The X86 backend has these language extensions:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1849
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1850 Memory references off the GS segment
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1851 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1852
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1853 Annotating a pointer with address space #256 causes it to be code generated
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1854 relative to the X86 GS segment register, and address space #257 causes it to be
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1855 relative to the X86 FS segment. Note that this is a very very low-level
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1856 feature that should only be used if you know what you're doing (for example in
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1857 an OS kernel).
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1858
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1859 Here is an example:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1860
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1861 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1862
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1863 #define GS_RELATIVE __attribute__((address_space(256)))
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1864 int foo(int GS_RELATIVE *P) {
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1865 return *P;
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1866 }
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1867
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1868 Which compiles to (on X86-32):
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1869
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1870 .. code-block:: gas
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1871
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1872 _foo:
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1873 movl 4(%esp), %eax
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1874 movl %gs:(%eax), %eax
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1875 ret
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1876
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1877 Extensions for Static Analysis
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1878 ==============================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1879
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1880 Clang supports additional attributes that are useful for documenting program
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1881 invariants and rules for static analysis tools, such as the `Clang Static
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1882 Analyzer <http://clang-analyzer.llvm.org/>`_. These attributes are documented
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1883 in the analyzer's `list of source-level annotations
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1884 <http://clang-analyzer.llvm.org/annotations.html>`_.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1885
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1886
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1887 Extensions for Dynamic Analysis
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1888 ===============================
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1889
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1890 Use ``__has_feature(address_sanitizer)`` to check if the code is being built
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1891 with :doc:`AddressSanitizer`.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1892
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1893 Use ``__has_feature(thread_sanitizer)`` to check if the code is being built
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1894 with :doc:`ThreadSanitizer`.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1895
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1896 Use ``__has_feature(memory_sanitizer)`` to check if the code is being built
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1897 with :doc:`MemorySanitizer`.
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1898
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1899 Use ``__has_feature(safe_stack)`` to check if the code is being built
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1900 with :doc:`SafeStack`.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	1901
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1902
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1903 Extensions for selectively disabling optimization
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1904 =================================================
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1905
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1906 Clang provides a mechanism for selectively disabling optimizations in functions
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1907 and methods.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1908
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1909 To disable optimizations in a single function definition, the GNU-style or C++11
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1910 non-standard attribute ``optnone`` can be used.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1911
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1912 .. code-block:: c++
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1913
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1914 // The following functions will not be optimized.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1915 // GNU-style attribute
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1916 __attribute__((optnone)) int foo() {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1917 // ... code
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1918 }
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1919 // C++11 attribute
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1920 [[clang::optnone]] int bar() {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1921 // ... code
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1922 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1923
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1924 To facilitate disabling optimization for a range of function definitions, a
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1925 range-based pragma is provided. Its syntax is ``#pragma clang optimize``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1926 followed by ``off`` or ``on``.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1927
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1928 All function definitions in the region between an ``off`` and the following
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1929 ``on`` will be decorated with the ``optnone`` attribute unless doing so would
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1930 conflict with explicit attributes already present on the function (e.g. the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1931 ones that control inlining).
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1932
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1933 .. code-block:: c++
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1934
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1935 #pragma clang optimize off
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1936 // This function will be decorated with optnone.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1937 int foo() {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1938 // ... code
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1939 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1940
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1941 // optnone conflicts with always_inline, so bar() will not be decorated.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1942 __attribute__((always_inline)) int bar() {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1943 // ... code
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1944 }
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1945 #pragma clang optimize on
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1946
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1947 If no ``on`` is found to close an ``off`` region, the end of the region is the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1948 end of the compilation unit.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1949
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1950 Note that a stray ``#pragma clang optimize on`` does not selectively enable
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1951 additional optimizations when compiling at low optimization levels. This feature
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1952 can only be used to selectively disable optimizations.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1953
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1954 The pragma has an effect on functions only at the point of their definition; for
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1955 function templates, this means that the state of the pragma at the point of an
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1956 instantiation is not necessarily relevant. Consider the following example:
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1957
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1958 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1959
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1960 template<typename T> T twice(T t) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1961 return 2 * t;
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1962 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1963
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1964 #pragma clang optimize off
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1965 template<typename T> T thrice(T t) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1966 return 3 * t;
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1967 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1968
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1969 int container(int a, int b) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1970 return twice(a) + thrice(b);
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1971 }
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1972 #pragma clang optimize on
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1973
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1974 In this example, the definition of the template function ``twice`` is outside
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1975 the pragma region, whereas the definition of ``thrice`` is inside the region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1976 The ``container`` function is also in the region and will not be optimized, but
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1977 it causes the instantiation of ``twice`` and ``thrice`` with an ``int`` type; of
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1978 these two instantiations, ``twice`` will be optimized (because its definition
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1979 was outside the region) and ``thrice`` will not be optimized.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1980
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1981 Extensions for loop hint optimizations
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1982 ======================================
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1983
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1984 The ``#pragma clang loop`` directive is used to specify hints for optimizing the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1985 subsequent for, while, do-while, or c++11 range-based for loop. The directive
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1986 provides options for vectorization, interleaving, and unrolling. Loop hints can
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1987 be specified before any loop and will be ignored if the optimization is not safe
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1988 to apply.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1989
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1990 Vectorization and Interleaving
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1991 ------------------------------
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1992
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1993 A vectorized loop performs multiple iterations of the original loop
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1994 in parallel using vector instructions. The instruction set of the target
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1995 processor determines which vector instructions are available and their vector
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1996 widths. This restricts the types of loops that can be vectorized. The vectorizer
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1997 automatically determines if the loop is safe and profitable to vectorize. A
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	1998 vector instruction cost model is used to select the vector width.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1999
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2000 Interleaving multiple loop iterations allows modern processors to further
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2001 improve instruction-level parallelism (ILP) using advanced hardware features,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2002 such as multiple execution units and out-of-order execution. The vectorizer uses
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2003 a cost model that depends on the register pressure and generated code size to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2004 select the interleaving count.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2005
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2006 Vectorization is enabled by ``vectorize(enable)`` and interleaving is enabled
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2007 by ``interleave(enable)``. This is useful when compiling with ``-Os`` to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2008 manually enable vectorization or interleaving.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2009
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2010 .. code-block:: c++
95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2011
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2012 #pragma clang loop vectorize(enable)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2013 #pragma clang loop interleave(enable)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2014 for(...) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2015 ...
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2016 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2017
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2018 The vector width is specified by ``vectorize_width(_value_)`` and the interleave
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2019 count is specified by ``interleave_count(_value_)``, where
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2020 _value_ is a positive integer. This is useful for specifying the optimal
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2021 width/count of the set of target architectures supported by your application.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2022
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2023 .. code-block:: c++
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2024
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2025 #pragma clang loop vectorize_width(2)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2026 #pragma clang loop interleave_count(2)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2027 for(...) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2028 ...
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2029 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2030
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2031 Specifying a width/count of 1 disables the optimization, and is equivalent to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2032 ``vectorize(disable)`` or ``interleave(disable)``.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2033
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2034 Loop Unrolling
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2035 --------------
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2036
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2037 Unrolling a loop reduces the loop control overhead and exposes more
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2038 opportunities for ILP. Loops can be fully or partially unrolled. Full unrolling
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2039 eliminates the loop and replaces it with an enumerated sequence of loop
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2040 iterations. Full unrolling is only possible if the loop trip count is known at
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2041 compile time. Partial unrolling replicates the loop body within the loop and
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2042 reduces the trip count.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2043
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2044 If ``unroll(enable)`` is specified the unroller will attempt to fully unroll the
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2045 loop if the trip count is known at compile time. If the fully unrolled code size
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2046 is greater than an internal limit the loop will be partially unrolled up to this
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2047 limit. If the trip count is not known at compile time the loop will be partially
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2048 unrolled with a heuristically chosen unroll factor.
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2049
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2050 .. code-block:: c++
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2051
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2052 #pragma clang loop unroll(enable)
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2053 for(...) {
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2054 ...
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2055 }
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2056
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2057 If ``unroll(full)`` is specified the unroller will attempt to fully unroll the
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2058 loop if the trip count is known at compile time identically to
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2059 ``unroll(enable)``. However, with ``unroll(full)`` the loop will not be unrolled
afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2060 if the loop count is not known at compile time.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2061
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2062 .. code-block:: c++
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2063
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2064 #pragma clang loop unroll(full)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2065 for(...) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2066 ...
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2067 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2068
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2069 The unroll count can be specified explicitly with ``unroll_count(_value_)`` where
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2070 _value_ is a positive integer. If this value is greater than the trip count the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2071 loop will be fully unrolled. Otherwise the loop is partially unrolled subject
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 83 diff changeset	2072 to the same code size limit as with ``unroll(enable)``.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2073
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2074 .. code-block:: c++
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2075
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2076 #pragma clang loop unroll_count(8)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2077 for(...) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2078 ...
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2079 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2080
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2081 Unrolling of a loop can be prevented by specifying ``unroll(disable)``.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2082
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2083 Additional Information
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2084 ----------------------
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2085
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2086 For convenience multiple loop hints can be specified on a single line.
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2087
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2088 .. code-block:: c++
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2089
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2090 #pragma clang loop vectorize_width(4) interleave_count(8)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2091 for(...) {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2092 ...
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2093 }
0 95c75e76d11b LLVM 3.4 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2094
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2095 If an optimization cannot be applied any hints that apply to it will be ignored.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2096 For example, the hint ``vectorize_width(4)`` is ignored if the loop is not
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2097 proven safe to vectorize. To identify and diagnose optimization issues use
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2098 `-Rpass`, `-Rpass-missed`, and `-Rpass-analysis` command line options. See the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 0 diff changeset	2099 user guide for details.

Mercurial > hg > CbC > CbC_llvm

annotate tools/clang/docs/LanguageExtensions.rst @ 95:afa8332a0e37 LLVM3.8