Mercurial > hg > Members > tobaru > cbc > CbC_llvm

annotate docs/HowToSubmitABug.rst @ 3:9ad51c7bc036

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
1st commit. remove git dir and add all files.
author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Wed, 15 May 2013 06:43:32 +0900
parents
children 54457678186b
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
3
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
1 ================================
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
2 How to submit an LLVM bug report
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
3 ================================
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
4
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
5 Introduction - Got bugs?
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
6 ========================
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
7
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
8
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
9 If you're working with LLVM and run into a bug, we definitely want to know
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
10 about it. This document describes what you can do to increase the odds of
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
11 getting it fixed quickly.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
12
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
13 Basically you have to do two things at a minimum. First, decide whether
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
14 the bug `crashes the compiler`_ (or an LLVM pass), or if the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
15 compiler is `miscompiling`_ the program (i.e., the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
16 compiler successfully produces an executable, but it doesn't run right).
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
17 Based on what type of bug it is, follow the instructions in the linked
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
18 section to narrow down the bug so that the person who fixes it will be able
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
19 to find the problem more easily.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
20
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
21 Once you have a reduced test-case, go to `the LLVM Bug Tracking System
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
22 <http://llvm.org/bugs/enter_bug.cgi>`_ and fill out the form with the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
23 necessary details (note that you don't need to pick a category, just use
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
24 the "new-bugs" category if you're not sure). The bug description should
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
25 contain the following information:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
26
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
27 * All information necessary to reproduce the problem.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
28 * The reduced test-case that triggers the bug.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
29 * The location where you obtained LLVM (if not from our Subversion
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
30 repository).
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
31
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
32 Thanks for helping us make LLVM better!
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
33
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
34 .. _crashes the compiler:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
35
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
36 Crashing Bugs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
37 =============
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
38
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
39 More often than not, bugs in the compiler cause it to crash---often due to
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
40 an assertion failure of some sort. The most important piece of the puzzle
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
41 is to figure out if it is crashing in the GCC front-end or if it is one of
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
42 the LLVM libraries (e.g. the optimizer or code generator) that has
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
43 problems.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
44
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
45 To figure out which component is crashing (the front-end, optimizer or code
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
46 generator), run the ``llvm-gcc`` command line as you were when the crash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
47 occurred, but with the following extra command line options:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
48
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
49 * ``-O0 -emit-llvm``: If ``llvm-gcc`` still crashes when passed these
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
50 options (which disable the optimizer and code generator), then the crash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
51 is in the front-end. Jump ahead to the section on :ref:`front-end bugs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
52 <front-end>`.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
53
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
54 * ``-emit-llvm``: If ``llvm-gcc`` crashes with this option (which disables
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
55 the code generator), you found an optimizer bug. Jump ahead to
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
56 `compile-time optimization bugs`_.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
57
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
58 * Otherwise, you have a code generator crash. Jump ahead to `code
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
59 generator bugs`_.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
60
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
61 .. _front-end bug:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
62 .. _front-end:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
63
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
64 Front-end bugs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
65 --------------
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
66
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
67 If the problem is in the front-end, you should re-run the same ``llvm-gcc``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
68 command that resulted in the crash, but add the ``-save-temps`` option.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
69 The compiler will crash again, but it will leave behind a ``foo.i`` file
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
70 (containing preprocessed C source code) and possibly ``foo.s`` for each
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
71 compiled ``foo.c`` file. Send us the ``foo.i`` file, along with the options
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
72 you passed to ``llvm-gcc``, and a brief description of the error it caused.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
73
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
74 The `delta <http://delta.tigris.org/>`_ tool helps to reduce the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
75 preprocessed file down to the smallest amount of code that still replicates
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
76 the problem. You're encouraged to use delta to reduce the code to make the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
77 developers' lives easier. `This website
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
78 <http://gcc.gnu.org/wiki/A_guide_to_testcase_reduction>`_ has instructions
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
79 on the best way to use delta.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
80
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
81 .. _compile-time optimization bugs:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
82
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
83 Compile-time optimization bugs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
84 ------------------------------
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
85
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
86 If you find that a bug crashes in the optimizer, compile your test-case to a
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
87 ``.bc`` file by passing "``-emit-llvm -O0 -c -o foo.bc``".
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
88 Then run:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
89
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
90 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
91
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
92 opt -std-compile-opts -debug-pass=Arguments foo.bc -disable-output
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
93
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
94 This command should do two things: it should print out a list of passes, and
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
95 then it should crash in the same way as llvm-gcc. If it doesn't crash, please
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
96 follow the instructions for a `front-end bug`_.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
97
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
98 If this does crash, then you should be able to debug this with the following
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
99 bugpoint command:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
100
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
101 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
102
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
103 bugpoint foo.bc <list of passes printed by opt>
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
104
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
105 Please run this, then file a bug with the instructions and reduced .bc
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
106 files that bugpoint emits. If something goes wrong with bugpoint, please
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
107 submit the "foo.bc" file and the list of passes printed by ``opt``.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
108
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
109 .. _code generator bugs:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
110
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
111 Code generator bugs
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
112 -------------------
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
113
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
114 If you find a bug that crashes llvm-gcc in the code generator, compile your
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
115 source file to a .bc file by passing "``-emit-llvm -c -o foo.bc``" to
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
116 llvm-gcc (in addition to the options you already pass). Once your have
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
117 foo.bc, one of the following commands should fail:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
118
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
119 #. ``llc foo.bc``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
120 #. ``llc foo.bc -relocation-model=pic``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
121 #. ``llc foo.bc -relocation-model=static``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
122
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
123 If none of these crash, please follow the instructions for a `front-end
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
124 bug`_. If one of these do crash, you should be able to reduce this with
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
125 one of the following bugpoint command lines (use the one corresponding to
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
126 the command above that failed):
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
127
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
128 #. ``bugpoint -run-llc foo.bc``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
129 #. ``bugpoint -run-llc foo.bc --tool-args -relocation-model=pic``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
130 #. ``bugpoint -run-llc foo.bc --tool-args -relocation-model=static``
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
131
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
132 Please run this, then file a bug with the instructions and reduced .bc file
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
133 that bugpoint emits. If something goes wrong with bugpoint, please submit
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
134 the "foo.bc" file and the option that llc crashes with.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
135
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
136 .. _miscompiling:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
137
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
138 Miscompilations
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
139 ===============
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
140
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
141 If llvm-gcc successfully produces an executable, but that executable
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
142 doesn't run right, this is either a bug in the code or a bug in the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
143 compiler. The first thing to check is to make sure it is not using
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
144 undefined behavior (e.g. reading a variable before it is defined). In
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
145 particular, check to see if the program `valgrind
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
146 <http://valgrind.org/>`_'s clean, passes purify, or some other memory
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
147 checker tool. Many of the "LLVM bugs" that we have chased down ended up
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
148 being bugs in the program being compiled, not LLVM.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
149
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
150 Once you determine that the program itself is not buggy, you should choose
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
151 which code generator you wish to compile the program with (e.g. LLC or the JIT)
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
152 and optionally a series of LLVM passes to run. For example:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
153
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
154 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
155
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
156 bugpoint -run-llc [... optzn passes ...] file-to-test.bc --args -- [program arguments]
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
157
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
158 bugpoint will try to narrow down your list of passes to the one pass that
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
159 causes an error, and simplify the bitcode file as much as it can to assist
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
160 you. It will print a message letting you know how to reproduce the
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
161 resulting error.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
162
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
163 Incorrect code generation
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
164 =========================
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
165
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
166 Similarly to debugging incorrect compilation by mis-behaving passes, you
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
167 can debug incorrect code generation by either LLC or the JIT, using
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
168 ``bugpoint``. The process ``bugpoint`` follows in this case is to try to
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
169 narrow the code down to a function that is miscompiled by one or the other
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
170 method, but since for correctness, the entire program must be run,
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
171 ``bugpoint`` will compile the code it deems to not be affected with the C
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
172 Backend, and then link in the shared object it generates.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
173
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
174 To debug the JIT:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
175
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
176 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
177
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
178 bugpoint -run-jit -output=[correct output file] [bitcode file] \
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
179 --tool-args -- [arguments to pass to lli] \
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
180 --args -- [program arguments]
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
181
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
182 Similarly, to debug the LLC, one would run:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
183
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
184 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
185
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
186 bugpoint -run-llc -output=[correct output file] [bitcode file] \
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
187 --tool-args -- [arguments to pass to llc] \
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
188 --args -- [program arguments]
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
189
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
190 **Special note:** if you are debugging MultiSource or SPEC tests that
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
191 already exist in the ``llvm/test`` hierarchy, there is an easier way to
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
192 debug the JIT, LLC, and CBE, using the pre-written Makefile targets, which
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
193 will pass the program options specified in the Makefiles:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
194
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
195 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
196
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
197 cd llvm/test/../../program
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
198 make bugpoint-jit
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
199
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
200 At the end of a successful ``bugpoint`` run, you will be presented
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
201 with two bitcode files: a *safe* file which can be compiled with the C
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
202 backend and the *test* file which either LLC or the JIT
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
203 mis-codegenerates, and thus causes the error.
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
204
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
205 To reproduce the error that ``bugpoint`` found, it is sufficient to do
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
206 the following:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
207
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
208 #. Regenerate the shared object from the safe bitcode file:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
209
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
210 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
211
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
212 llc -march=c safe.bc -o safe.c
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
213 gcc -shared safe.c -o safe.so
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
214
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
215 #. If debugging LLC, compile test bitcode native and link with the shared
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
216 object:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
217
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
218 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
219
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
220 llc test.bc -o test.s
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
221 gcc test.s safe.so -o test.llc
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
222 ./test.llc [program options]
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
223
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
224 #. If debugging the JIT, load the shared object and supply the test
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
225 bitcode:
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
226
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
227 .. code-block:: bash
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
228
9ad51c7bc036 1st commit. remove git dir and add all files.
Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
parents:
diff changeset
229 lli -load=safe.so test.bc [program options]