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author	Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date	Sun, 31 Jan 2016 17:34:49 +0900
parents	7d135dc70f03
children	1172e4bd9c6f

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77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	1 .. role:: raw-html(raw)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	2 :format: html
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	3
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	4 =================================
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	5 LLVM Code Coverage Mapping Format
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	6 =================================
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	7
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	8 .. contents::
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	9 :local:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	10
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	11 Introduction
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	12 ============
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	13
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	14 LLVM's code coverage mapping format is used to provide code coverage
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	15 analysis using LLVM's and Clang's instrumenation based profiling
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	16 (Clang's ``-fprofile-instr-generate`` option).
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	17
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	18 This document is aimed at those who use LLVM's code coverage mapping to provide
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	19 code coverage analysis for their own programs, and for those who would like
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	20 to know how it works under the hood. A prior knowledge of how Clang's profile
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	21 guided optimization works is useful, but not required.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	22
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	23 We start by showing how to use LLVM and Clang for code coverage analysis,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	24 then we briefly desribe LLVM's code coverage mapping format and the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	25 way that Clang and LLVM's code coverage tool work with this format. After
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	26 the basics are down, more advanced features of the coverage mapping format
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	27 are discussed - such as the data structures, LLVM IR representation and
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	28 the binary encoding.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	29
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	30 Quick Start
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	31 ===========
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	32
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	33 Here's a short story that describes how to generate code coverage overview
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	34 for a sample source file called test.c.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	35
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	36 * First, compile an instrumented version of your program using Clang's
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	37 ``-fprofile-instr-generate`` option with the additional ``-fcoverage-mapping``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	38 option:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	39
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	40 ``clang -o test -fprofile-instr-generate -fcoverage-mapping test.c``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	41 * Then, run the instrumented binary. The runtime will produce a file called
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	42 default.profraw containing the raw profile instrumentation data:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	43
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	44 ``./test``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	45 * After that, merge the profile data using the llvm-profdata tool:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	46
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	47 ``llvm-profdata merge -o test.profdata default.profraw``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	48 * Finally, run LLVM's code coverage tool (llvm-cov) to produce the code
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	49 coverage overview for the sample source file:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	50
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	51 ``llvm-cov show ./test -instr-profile=test.profdata test.c``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	52
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	53 High Level Overview
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	54 ===================
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	55
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	56 LLVM's code coverage mapping format is designed to be a self contained
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	57 data format, that can be embedded into the LLVM IR and object files.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	58 It's described in this document as a mapping format because its goal is
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	59 to store the data that is required for a code coverage tool to map between
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	60 the specific source ranges in a file and the execution counts obtained
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	61 after running the instrumented version of the program.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	62
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	63 The mapping data is used in two places in the code coverage process:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	64
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	65 1. When clang compiles a source file with ``-fcoverage-mapping``, it
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	66 generates the mapping information that describes the mapping between the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	67 source ranges and the profiling instrumentation counters.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	68 This information gets embedded into the LLVM IR and conveniently
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	69 ends up in the final executable file when the program is linked.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	70
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	71 2. It is also used by llvm-cov - the mapping information is extracted from an
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	72 object file and is used to associate the execution counts (the values of the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	73 profile instrumentation counters), and the source ranges in a file.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	74 After that, the tool is able to generate various code coverage reports
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	75 for the program.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	76
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	77 The coverage mapping format aims to be a "universal format" that would be
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	78 suitable for usage by any frontend, and not just by Clang. It also aims to
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	79 provide the frontend the possibility of generating the minimal coverage mapping
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	80 data in order to reduce the size of the IR and object files - for example,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	81 instead of emitting mapping information for each statement in a function, the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	82 frontend is allowed to group the statements with the same execution count into
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	83 regions of code, and emit the mapping information only for those regions.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	84
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	85 Advanced Concepts
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	86 =================
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	87
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	88 The remainder of this guide is meant to give you insight into the way the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	89 coverage mapping format works.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	90
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	91 The coverage mapping format operates on a per-function level as the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	92 profile instrumentation counters are associated with a specific function.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	93 For each function that requires code coverage, the frontend has to create
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	94 coverage mapping data that can map between the source code ranges and
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	95 the profile instrumentation counters for that function.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	96
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	97 Mapping Region
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	98 --------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	99
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	100 The function's coverage mapping data contains an array of mapping regions.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	101 A mapping region stores the `source code range`_ that is covered by this region,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	102 the `file id <coverage file id_>`_, the `coverage mapping counter`_ and
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	103 the region's kind.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	104 There are several kinds of mapping regions:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	105
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	106 * Code regions associate portions of source code and `coverage mapping
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	107 counters`_. They make up the majority of the mapping regions. They are used
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	108 by the code coverage tool to compute the execution counts for lines,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	109 highlight the regions of code that were never executed, and to obtain
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	110 the various code coverage statistics for a function.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	111 For example:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	112
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	113 :raw-html:`<pre class='highlight' style='line-height:initial;'><span>int main(int argc, const char *argv[]) </span><span style='background-color:#4A789C'>{ </span> <span class='c1'>// Code Region from 1:40 to 9:2</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	114 <span style='background-color:#4A789C'> </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	115 <span style='background-color:#4A789C'> if (argc > 1) </span><span style='background-color:#85C1F5'>{ </span> <span class='c1'>// Code Region from 3:17 to 5:4</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	116 <span style='background-color:#85C1F5'> printf("%s\n", argv[1]); </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	117 <span style='background-color:#85C1F5'> }</span><span style='background-color:#4A789C'> else </span><span style='background-color:#F6D55D'>{ </span> <span class='c1'>// Code Region from 5:10 to 7:4</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	118 <span style='background-color:#F6D55D'> printf("\n"); </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	119 <span style='background-color:#F6D55D'> }</span><span style='background-color:#4A789C'> </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	120 <span style='background-color:#4A789C'> return 0; </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	121 <span style='background-color:#4A789C'>}</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	122 </pre>`
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	123 * Skipped regions are used to represent source ranges that were skipped
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	124 by Clang's preprocessor. They don't associate with
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	125 `coverage mapping counters`_, as the frontend knows that they are never
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	126 executed. They are used by the code coverage tool to mark the skipped lines
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	127 inside a function as non-code lines that don't have execution counts.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	128 For example:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	129
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	130 :raw-html:`<pre class='highlight' style='line-height:initial;'><span>int main() </span><span style='background-color:#4A789C'>{ </span> <span class='c1'>// Code Region from 1:12 to 6:2</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	131 <span style='background-color:#85C1F5'>#ifdef DEBUG </span> <span class='c1'>// Skipped Region from 2:1 to 4:2</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	132 <span style='background-color:#85C1F5'> printf("Hello world"); </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	133 <span style='background-color:#85C1F5'>#</span><span style='background-color:#4A789C'>endif </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	134 <span style='background-color:#4A789C'> return 0; </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	135 <span style='background-color:#4A789C'>}</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	136 </pre>`
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	137 * Expansion regions are used to represent Clang's macro expansions. They
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	138 have an additional property - expanded file id. This property can be
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	139 used by the code coverage tool to find the mapping regions that are created
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	140 as a result of this macro expansion, by checking if their file id matches the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	141 expanded file id. They don't associate with `coverage mapping counters`_,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	142 as the code coverage tool can determine the execution count for this region
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	143 by looking up the execution count of the first region with a corresponding
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	144 file id.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	145 For example:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	146
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	147 :raw-html:`<pre class='highlight' style='line-height:initial;'><span>int func(int x) </span><span style='background-color:#4A789C'>{ </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	148 <span style='background-color:#4A789C'> #define MAX(x,y) </span><span style='background-color:#85C1F5'>((x) > (y)? </span><span style='background-color:#F6D55D'>(x)</span><span style='background-color:#85C1F5'> : </span><span style='background-color:#F4BA70'>(y)</span><span style='background-color:#85C1F5'>)</span><span style='background-color:#4A789C'> </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	149 <span style='background-color:#4A789C'> return </span><span style='background-color:#7FCA9F'>MAX</span><span style='background-color:#4A789C'>(x, 42); </span> <span class='c1'>// Expansion Region from 3:10 to 3:13</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	150 <span style='background-color:#4A789C'>}</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	151 </pre>`
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	152
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	153 .. _source code range:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	154
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	155 Source Range:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	156 ^^^^^^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	157
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	158 The source range record contains the starting and ending location of a certain
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	159 mapping region. Both locations include the line and the column numbers.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	160
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	161 .. _coverage file id:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	162
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	163 File ID:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	164 ^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	165
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	166 The file id an integer value that tells us
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	167 in which source file or macro expansion is this region located.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	168 It enables Clang to produce mapping information for the code
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	169 defined inside macros, like this example demonstrates:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	170
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	171 :raw-html:`<pre class='highlight' style='line-height:initial;'><span>void func(const char *str) </span><span style='background-color:#4A789C'>{ </span> <span class='c1'>// Code Region from 1:28 to 6:2 with file id 0</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	172 <span style='background-color:#4A789C'> #define PUT </span><span style='background-color:#85C1F5'>printf("%s\n", str)</span><span style='background-color:#4A789C'> </span> <span class='c1'>// 2 Code Regions from 2:15 to 2:34 with file ids 1 and 2</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	173 <span style='background-color:#4A789C'> if(*str) </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	174 <span style='background-color:#4A789C'> </span><span style='background-color:#F6D55D'>PUT</span><span style='background-color:#4A789C'>; </span> <span class='c1'>// Expansion Region from 4:5 to 4:8 with file id 0 that expands a macro with file id 1</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	175 <span style='background-color:#4A789C'> </span><span style='background-color:#F6D55D'>PUT</span><span style='background-color:#4A789C'>; </span> <span class='c1'>// Expansion Region from 5:3 to 5:6 with file id 0 that expands a macro with file id 2</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	176 <span style='background-color:#4A789C'>}</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	177 </pre>`
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	178
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	179 .. _coverage mapping counter:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	180 .. _coverage mapping counters:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	181
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	182 Counter:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	183 ^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	184
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	185 A coverage mapping counter can represents a reference to the profile
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	186 instrumentation counter. The execution count for a region with such counter
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	187 is determined by looking up the value of the corresponding profile
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	188 instrumentation counter.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	189
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	190 It can also represent a binary arithmetical expression that operates on
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	191 coverage mapping counters or other expressions.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	192 The execution count for a region with an expression counter is determined by
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	193 evaluating the expression's arguments and then adding them together or
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	194 subtracting them from one another.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	195 In the example below, a subtraction expression is used to compute the execution
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	196 count for the compound statement that follows the else keyword:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	197
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	198 :raw-html:`<pre class='highlight' style='line-height:initial;'><span>int main(int argc, const char *argv[]) </span><span style='background-color:#4A789C'>{ </span> <span class='c1'>// Region's counter is a reference to the profile counter #0</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	199 <span style='background-color:#4A789C'> </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	200 <span style='background-color:#4A789C'> if (argc > 1) </span><span style='background-color:#85C1F5'>{ </span> <span class='c1'>// Region's counter is a reference to the profile counter #1</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	201 <span style='background-color:#85C1F5'> printf("%s\n", argv[1]); </span><span> </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	202 <span style='background-color:#85C1F5'> }</span><span style='background-color:#4A789C'> else </span><span style='background-color:#F6D55D'>{ </span> <span class='c1'>// Region's counter is an expression (reference to the profile counter #0 - reference to the profile counter #1)</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	203 <span style='background-color:#F6D55D'> printf("\n"); </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	204 <span style='background-color:#F6D55D'> }</span><span style='background-color:#4A789C'> </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	205 <span style='background-color:#4A789C'> return 0; </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	206 <span style='background-color:#4A789C'>}</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	207 </pre>`
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	208
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	209 Finally, a coverage mapping counter can also represent an execution count of
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	210 of zero. The zero counter is used to provide coverage mapping for
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	211 unreachable statements and expressions, like in the example below:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	212
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	213 :raw-html:`<pre class='highlight' style='line-height:initial;'><span>int main() </span><span style='background-color:#4A789C'>{ </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	214 <span style='background-color:#4A789C'> return 0; </span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	215 <span style='background-color:#4A789C'> </span><span style='background-color:#85C1F5'>printf("Hello world!\n")</span><span style='background-color:#4A789C'>; </span> <span class='c1'>// Unreachable region's counter is zero</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	216 <span style='background-color:#4A789C'>}</span>
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	217 </pre>`
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	218
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	219 The zero counters allow the code coverage tool to display proper line execution
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	220 counts for the unreachable lines and highlight the unreachable code.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	221 Without them, the tool would think that those lines and regions were still
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	222 executed, as it doesn't possess the frontend's knowledge.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	223
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	224 LLVM IR Representation
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	225 ======================
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	226
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	227 The coverage mapping data is stored in the LLVM IR using a single global
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	228 constant structure variable called __llvm_coverage_mapping
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	229 with the __llvm_covmap section specifier.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	230
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	231 For example, let’s consider a C file and how it gets compiled to LLVM:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	232
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	233 .. _coverage mapping sample:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	234
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	235 .. code-block:: c
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	236
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	237 int foo() {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	238 return 42;
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	239 }
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	240 int bar() {
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	241 return 13;
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	242 }
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	243
100 7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	244 The coverage mapping variable generated by Clang has 3 fields:
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	245
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	246 * Coverage mapping header.
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	247
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	248 * An array of function records.
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	249
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	250 * Coverage mapping data which is an array of bytes. Zero paddings are added at the end to force 8 byte alignment.
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	251
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	252 .. code-block:: llvm
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	253
100 7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	254 @__llvm_coverage_mapping = internal constant { { i32, i32, i32, i32 }, [2 x { i8*, i32, i32 }], [40 x i8] }
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	255 {
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	256 { i32, i32, i32, i32 } ; Coverage map header
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	257 {
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	258 i32 2, ; The number of function records
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	259 i32 20, ; The length of the string that contains the encoded translation unit filenames
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	260 i32 20, ; The length of the string that contains the encoded coverage mapping data
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	261 i32 0, ; Coverage mapping format version
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	262 },
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	263 [2 x { i8*, i32, i32 }] [ ; Function records
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	264 { i8, i32, i32 } { i8 getelementptr inbounds ([3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), ; Function's name
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	265 i32 3, ; Function's name length
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	266 i32 9 ; Function's encoded coverage mapping data string length
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	267 },
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	268 { i8, i32, i32 } { i8 getelementptr inbounds ([3 x i8]* @__llvm_profile_name_bar, i32 0, i32 0), ; Function's name
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	269 i32 3, ; Function's name length
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	270 i32 9 ; Function's encoded coverage mapping data string length
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	271 }],
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	272 [40 x i8] c"..." ; Encoded data (dissected later)
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	273 }, section "__llvm_covmap", align 8
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	274
100 7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	275 Coverage Mapping Header:
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	276 ------------------------
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	277
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	278 The coverage mapping header has the following fields:
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	279
100 7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	280 * The number of function records.
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	281
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	282 * The length of the string in the third field of __llvm_coverage_mapping that contains the encoded translation unit filenames.
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	283
100 7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	284 * The length of the string in the third field of __llvm_coverage_mapping that contains the encoded coverage mapping data.
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	285
7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	286 * The format version. 0 is the first (current) version of the coverage mapping format.
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	287
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	288 .. _function records:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	289
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	290 Function record:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	291 ----------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	292
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	293 A function record is a structure of the following type:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	294
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	295 .. code-block:: llvm
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	296
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	297 { i8*, i32, i32 }
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	298
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	299 It contains the pointer to the function's name, function's name length,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	300 and the length of the encoded mapping data for that function.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	301
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	302 Encoded data:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	303 -------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	304
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	305 The encoded data is stored in a single string that contains
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	306 the encoded filenames used by this translation unit and the encoded coverage
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	307 mapping data for each function in this translation unit.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	308
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	309 The encoded data has the following structure:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	310
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	311 ``[filenames, coverageMappingDataForFunctionRecord0, coverageMappingDataForFunctionRecord1, ..., padding]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	312
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	313 If necessary, the encoded data is padded with zeroes so that the size
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	314 of the data string is rounded up to the nearest multiple of 8 bytes.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	315
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	316 Dissecting the sample:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	317 ^^^^^^^^^^^^^^^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	318
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	319 Here's an overview of the encoded data that was stored in the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	320 IR for the `coverage mapping sample`_ that was shown earlier:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	321
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	322 * The IR contains the following string constant that represents the encoded
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	323 coverage mapping data for the sample translation unit:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	324
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	325 .. code-block:: llvm
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	326
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	327 c"\01\12/Users/alex/test.c\01\00\00\01\01\01\0C\02\02\01\00\00\01\01\04\0C\02\02\00\00"
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	328
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	329 * The string contains values that are encoded in the LEB128 format, which is
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	330 used throughout for storing integers. It also contains a string value.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	331
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	332 * The length of the substring that contains the encoded translation unit
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	333 filenames is the value of the second field in the __llvm_coverage_mapping
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	334 structure, which is 20, thus the filenames are encoded in this string:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	335
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	336 .. code-block:: llvm
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	337
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	338 c"\01\12/Users/alex/test.c"
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	339
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	340 This string contains the following data:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	341
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	342 * Its first byte has a value of ``0x01``. It stores the number of filenames
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	343 contained in this string.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	344 * Its second byte stores the length of the first filename in this string.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	345 * The remaining 18 bytes are used to store the first filename.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	346
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	347 * The length of the substring that contains the encoded coverage mapping data
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	348 for the first function is the value of the third field in the first
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	349 structure in an array of `function records`_ stored in the
100 7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	350 third field of the __llvm_coverage_mapping structure, which is the 9.
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	351 Therefore, the coverage mapping for the first function record is encoded
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	352 in this string:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	353
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	354 .. code-block:: llvm
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	355
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	356 c"\01\00\00\01\01\01\0C\02\02"
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	357
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	358 This string consists of the following bytes:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	359
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	360 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	361 \| ``0x01`` \| The number of file ids used by this function. There is only one file id used by the mapping data in this function. \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	362 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	363 \| ``0x00`` \| An index into the filenames array which corresponds to the file "/Users/alex/test.c". \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	364 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	365 \| ``0x00`` \| The number of counter expressions used by this function. This function doesn't use any expressions. \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	366 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	367 \| ``0x01`` \| The number of mapping regions that are stored in an array for the function's file id #0. \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	368 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	369 \| ``0x01`` \| The coverage mapping counter for the first region in this function. The value of 1 tells us that it's a coverage \|
100 7d135dc70f03 LLVM 3.9 Miyagi Mitsuki <e135756@ie.u-ryukyu.ac.jp> parents: 95 diff changeset	370 \| \| mapping counter that is a reference to the profile instrumentation counter with an index of 0. \|
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	371 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	372 \| ``0x01`` \| The starting line of the first mapping region in this function. \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	373 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	374 \| ``0x0C`` \| The starting column of the first mapping region in this function. \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	375 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	376 \| ``0x02`` \| The ending line of the first mapping region in this function. \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	377 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	378 \| ``0x02`` \| The ending column of the first mapping region in this function. \|
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	379 +----------+-------------------------------------------------------------------------------------------------------------------------+
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	380
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	381 * The length of the substring that contains the encoded coverage mapping data
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	382 for the second function record is also 9. It's structured like the mapping data
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	383 for the first function record.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	384
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	385 * The two trailing bytes are zeroes and are used to pad the coverage mapping
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	386 data to give it the 8 byte alignment.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	387
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	388 Encoding
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	389 ========
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	390
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	391 The per-function coverage mapping data is encoded as a stream of bytes,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	392 with a simple structure. The structure consists of the encoding
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	393 `types <cvmtypes_>`_ like variable-length unsigned integers, that
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	394 are used to encode `File ID Mapping`_, `Counter Expressions`_ and
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	395 the `Mapping Regions`_.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	396
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	397 The format of the structure follows:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	398
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	399 ``[file id mapping, counter expressions, mapping regions]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	400
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	401 The translation unit filenames are encoded using the same encoding
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	402 `types <cvmtypes_>`_ as the per-function coverage mapping data, with the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	403 following structure:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	404
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	405 ``[numFilenames : LEB128, filename0 : string, filename1 : string, ...]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	406
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	407 .. _cvmtypes:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	408
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	409 Types
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	410 -----
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	411
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	412 This section describes the basic types that are used by the encoding format
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	413 and can appear after ``:`` in the ``[foo : type]`` description.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	414
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	415 .. _LEB128:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	416
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	417 LEB128
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	418 ^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	419
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	420 LEB128 is an unsigned interger value that is encoded using DWARF's LEB128
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	421 encoding, optimizing for the case where values are small
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	422 (1 byte for values less than 128).
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	423
95 afa8332a0e37 LLVM 3.8 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: 77 diff changeset	424 .. _Strings:
77 54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	425
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	426 Strings
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	427 ^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	428
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	429 ``[length : LEB128, characters...]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	430
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	431 String values are encoded with a `LEB value <LEB128_>`_ for the length
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	432 of the string and a sequence of bytes for its characters.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	433
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	434 .. _file id mapping:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	435
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	436 File ID Mapping
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	437 ---------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	438
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	439 ``[numIndices : LEB128, filenameIndex0 : LEB128, filenameIndex1 : LEB128, ...]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	440
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	441 File id mapping in a function's coverage mapping stream
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	442 contains the indices into the translation unit's filenames array.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	443
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	444 Counter
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	445 -------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	446
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	447 ``[value : LEB128]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	448
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	449 A `coverage mapping counter`_ is stored in a single `LEB value <LEB128_>`_.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	450 It is composed of two things --- the `tag <counter-tag_>`_
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	451 which is stored in the lowest 2 bits, and the `counter data`_ which is stored
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	452 in the remaining bits.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	453
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	454 .. _counter-tag:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	455
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	456 Tag:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	457 ^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	458
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	459 The counter's tag encodes the counter's kind
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	460 and, if the counter is an expression, the expression's kind.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	461 The possible tag values are:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	462
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	463 * 0 - The counter is zero.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	464
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	465 * 1 - The counter is a reference to the profile instrumentation counter.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	466
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	467 * 2 - The counter is a subtraction expression.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	468
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	469 * 3 - The counter is an addition expression.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	470
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	471 .. _counter data:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	472
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	473 Data:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	474 ^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	475
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	476 The counter's data is interpreted in the following manner:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	477
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	478 * When the counter is a reference to the profile instrumentation counter,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	479 then the counter's data is the id of the profile counter.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	480 * When the counter is an expression, then the counter's data
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	481 is the index into the array of counter expressions.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	482
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	483 .. _Counter Expressions:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	484
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	485 Counter Expressions
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	486 -------------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	487
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	488 ``[numExpressions : LEB128, expr0LHS : LEB128, expr0RHS : LEB128, expr1LHS : LEB128, expr1RHS : LEB128, ...]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	489
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	490 Counter expressions consist of two counters as they
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	491 represent binary arithmetic operations.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	492 The expression's kind is determined from the `tag <counter-tag_>`_ of the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	493 counter that references this expression.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	494
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	495 .. _Mapping Regions:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	496
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	497 Mapping Regions
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	498 ---------------
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	499
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	500 ``[numRegionArrays : LEB128, regionsForFile0, regionsForFile1, ...]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	501
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	502 The mapping regions are stored in an array of sub-arrays where every
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	503 region in a particular sub-array has the same file id.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	504
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	505 The file id for a sub-array of regions is the index of that
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	506 sub-array in the main array e.g. The first sub-array will have the file id
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	507 of 0.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	508
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	509 Sub-Array of Regions
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	510 ^^^^^^^^^^^^^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	511
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	512 ``[numRegions : LEB128, region0, region1, ...]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	513
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	514 The mapping regions for a specific file id are stored in an array that is
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	515 sorted in an ascending order by the region's starting location.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	516
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	517 Mapping Region
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	518 ^^^^^^^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	519
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	520 ``[header, source range]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	521
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	522 The mapping region record contains two sub-records ---
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	523 the `header`_, which stores the counter and/or the region's kind,
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	524 and the `source range`_ that contains the starting and ending
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	525 location of this region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	526
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	527 .. _header:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	528
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	529 Header
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	530 ^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	531
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	532 ``[counter]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	533
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	534 or
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	535
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	536 ``[pseudo-counter]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	537
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	538 The header encodes the region's counter and the region's kind.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	539
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	540 The value of the counter's tag distinguishes between the counters and
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	541 pseudo-counters --- if the tag is zero, than this header contains a
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	542 pseudo-counter, otherwise this header contains an ordinary counter.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	543
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	544 Counter:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	545 """"""""
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	546
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	547 A mapping region whose header has a counter with a non-zero tag is
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	548 a code region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	549
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	550 Pseudo-Counter:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	551 """""""""""""""
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	552
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	553 ``[value : LEB128]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	554
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	555 A pseudo-counter is stored in a single `LEB value <LEB128_>`_, just like
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	556 the ordinary counter. It has the following interpretation:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	557
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	558 * bits 0-1: tag, which is always 0.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	559
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	560 * bit 2: expansionRegionTag. If this bit is set, then this mapping region
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	561 is an expansion region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	562
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	563 * remaining bits: data. If this region is an expansion region, then the data
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	564 contains the expanded file id of that region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	565
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	566 Otherwise, the data contains the region's kind. The possible region
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	567 kind values are:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	568
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	569 * 0 - This mapping region is a code region with a counter of zero.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	570 * 2 - This mapping region is a skipped region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	571
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	572 .. _source range:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	573
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	574 Source Range
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	575 ^^^^^^^^^^^^
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	576
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	577 ``[deltaLineStart : LEB128, columnStart : LEB128, numLines : LEB128, columnEnd : LEB128]``
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	578
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	579 The source range record contains the following fields:
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	580
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	581 * deltaLineStart: The difference between the starting line of the
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	582 current mapping region and the starting line of the previous mapping region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	583
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	584 If the current mapping region is the first region in the current
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	585 sub-array, then it stores the starting line of that region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	586
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	587 * columnStart: The starting column of the mapping region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	588
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	589 * numLines: The difference between the ending line and the starting line
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	590 of the current mapping region.
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	591
54457678186b LLVM 3.6 Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp> parents: diff changeset	592 * columnEnd: The ending column of the mapping region.

Mercurial > hg > Members > tobaru > cbc > CbC_llvm

annotate docs/CoverageMappingFormat.rst @ 107:a03ddd01be7e