README.skia
1# Copyright (c) 2012 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5These platform specific Makefiles are necesary to build yasm on different platforms. The rest of
6the yasm code is pulled into externals via the DEPS file.
7
8Chromium builds yasm using the below procedure. We take a few shortcuts. We mirror Chromium's
9yasm repositories in our DEPS file, and we copy these config files directly from Chromium.
10
11Excerpt from [chromium] //src/third_party/yasm/README.chromium:
12
13Instructions for recreating the yasm.gyp file.
14 1) Get a clean version of the yasm source tree. The clean tree can be found
15 at:
16
17 src/third_party/yasm/source/yasm
18
19 2) Run configure on the pristine source from a different directory (eg.,
20 /tmp/yasm_build). Running configure from another directory will keep
21 the source tree clean.
22
23 3) Next, capture all the output from a build of yasm. We will use the build
24 log as a reference for making the yasm.gyp file.
25
26 make yasm > yasm_build_log 2> yasm_build_err
27
28 4) Check yasm_build_err to see if there are any anomalies beyond yasm's
29 compiler warnings.
30
31 5) Grab the generated Makefile, libyasm-stdint.h, config.h, and put into
32 the correct platform location. For android platform, copy the files
33 generated for linux, but make sure that ENABLE_NLS is not defined to
34 allow mac host compiles to work. For ios, copy the files from mac.
35
36 src/third_party/yasm/source/config/[platform]
37
38 While we do not directly use the "Makefile" to build, it is needed by
39 the "genmodule" subprogram as input for creating the available modules
40 list.
41
42 6) Make sure all the subprograms are represented in yasm.gyp.
43
44 grep '^gcc' yasm_build_log |
45 grep -v ' -DHAVE_CONFIG_H '
46
47 The yasm build creates a bunch of subprograms that in-turn generate
48 more .c files in the build. Luckily the commands to generate the
49 subprogram do not have -DHAVE_CONFIG_H as a cflag.
50
51 From this list, make sure all the subprograms that are build have
52 appropriate targets in the yasm.gyp.
53
54 You will notice, when you get to the next step, that there are some
55 .c source files that are compiled both for yasm, and for genperf.
56
57 Those should go into the genperf_libs target so that they can be
58 shared by the genperf and yasm targets. Find those files by appending
59
60 | grep 'gp-'
61
62 to the command above.
63
64 7) Find all the source files used to build yasm proper.
65
66 grep -E '^gcc' yasm_build_log |
67 grep ' -DHAVE_CONFIG_H ' |
68 awk '{print $NF }' |
69 sed -e "s/'\.\/'\`//" | # Removes some garbage from the build line.
70 sort -u |
71 sed -e "s/\(.*\)/'\1',/" # Add quotes to each line.
72
73 Reversing the -DHAVE_CONFIG_H filter from the command above should
74 list the compile lines for yasm proper.
75
76 This should get you close, but you will need to manually examine this
77 list. However, some of the built products are still included in the
78 command above. Generally, if the source file is in the root directory,
79 it's a generated file.
80
81 Inspect the current yasm.gyp for a list of the subprograms and their
82 outputs.
83
84 Update the sources list in the yasm target accordingly. Read step #9
85 as well if you update the source list to avoid problems.
86
87 8) Update the actions for each of the subprograms.
88
89 Here is the real fun. For each subprogram created, you will need to
90 update the actions and rules in yasm.gyp that invoke the subprogram to
91 generate the files needed by the rest of the build.
92
93 I don't have any good succinct instructions for this. Grep the build
94 log for each subprogram invocation (eg., "./genversion"), look at
95 its command inputs and output, then verify our yasm.gyp does something
96 similar.
97
98 The good news is things likely only link or compile if this is done
99 right so you'll know if there is a problem.
100
101 Again, refer to the existing yasm.gyp for a guide to how the generated
102 files are used.
103
104 Here are a few gotchas:
105 1) genmodule, by default, writes module.c into the current
106 directory. This does not play nicely with gyp. We patch the
107 source during build to allow specifying a specific output file.
108
109 2) Most of the generated files, even though they are .c files, are
110 #included by other files in the build. Make sure they end up
111 in a directory that is in the include path for the build.
112 One of <(shared_generated_dir) or <(generated_dir) should work.
113
114 3) Some of the genperf output is #included while others need to be
115 compiled directly. That is why there are 2 different rules for
116 .gperf files in two targets.
117
118 9) Check for python scripts that are run.
119
120 grep python yasm_build_log
121
122 Yasm uses python scripts to generate the assembly code description
123 files in C++. Make sure to get these put into the gyp file properly as
124 well. An example is gen_x86_insn.py for x86 assembly.
125
126 Note that at least the gen_x86_insn.py script suffers from the same
127 problem as genmacro in that it outputs to the current directory by
128 default. The yasm.gyp build patches this file before invoking it to
129 allow specifying an output directory.
130
131 10) Recreate the 'AdditionalOptions!': [ '/analyze' ] block so that VC++
132 /analyze builds won't fail.
133
134 11) If all that's is finished, attempt to build....and cross your fingers.
135