projects/linux·blob master · refs

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1# SPDX-License-Identifier: GPL-2.0
2"""Setup script for perf python extension.
3
4This script is used to build and install the perf python binding.
5It handles compiler-specific flags, especially for clang, and configures
6the setuptools Extension.
7"""
8
9import os
10import shlex
11import shutil
12import subprocess
13import sysconfig
14
15from setuptools import setup, Extension
16from setuptools.command.build_ext import build_ext as _build_ext
17from setuptools.command.install_lib import install_lib as _install_lib
18
19
20def clang_has_option(cc: str, cc_args: list[str], src_feature_tests: str, option: str) -> bool:
21 """Check if clang supports a specific option.
22
23 Args:
24 cc: The compiler executable.
25 cc_args: Compiler arguments from CC environment variable.
26 src_feature_tests: Path to the feature tests directory.
27 option: The compiler option to check (e.g., "-mcet").
28
29 Returns:
30 True if the option is supported, False otherwise.
31 """
32 error_substrings = (
33 b"unknown argument",
34 b"is not supported",
35 b"unknown warning option"
36 )
37 cmd = [cc] + cc_args + [
38 option,
39 "-o", "/dev/null",
40 os.path.join(src_feature_tests, "test-hello.c")
41 ]
42 try:
43 res = subprocess.run(cmd, stderr=subprocess.PIPE, stdout=subprocess.DEVNULL, check=False)
44 cc_output = res.stderr.splitlines()
45 except OSError:
46 return False
47 return not any(any(error in line for error in error_substrings) for line in cc_output)
48
49
50def filter_clang_options(cc: str, cc_args: list[str], src_feature_tests: str) -> None:
51 """Filter out unsupported clang options from sysconfig CFLAGS and OPT.
52
53 Args:
54 cc: The compiler executable.
55 cc_args: Compiler arguments from CC environment variable.
56 src_feature_tests: Path to the feature tests directory.
57 """
58 config_vars = sysconfig.get_config_vars()
59 for var in ('CFLAGS', 'OPT'):
60 if var not in config_vars:
61 continue
62
63 # Split into individual flags using shlex to preserve quoted arguments
64 flags = shlex.split(config_vars[var])
65
66 # Remove -specs=...
67 flags = [f for f in flags if not f.startswith("-specs=")]
68
69 options = (
70 "-mcet",
71 "-fcf-protection",
72 "-fstack-clash-protection",
73 "-fstack-protector-strong",
74 "-fno-semantic-interposition",
75 "-ffat-lto-objects",
76 "-ftree-loop-distribute-patterns",
77 "-gno-variable-location-views"
78 )
79 for option in options:
80 if not clang_has_option(cc, cc_args, src_feature_tests, option):
81 # Remove the option and any variant (e.g. -option=...)
82 flags = [f for f in flags if not f.startswith(option)]
83
84 # Re-join flags preserving quoting
85 config_vars[var] = shlex.join(flags)
86
87
88class BuildExt(_build_ext):
89 """Custom build_ext command to set output directories."""
90
91 def __init__(self, *args, **kwargs):
92 self.build_lib = None
93 self.build_temp = None
94 super().__init__(*args, **kwargs)
95
96 def finalize_options(self) -> None:
97 _build_ext.finalize_options(self)
98 build_lib = os.getenv('PYTHON_EXTBUILD_LIB')
99 build_tmp = os.getenv('PYTHON_EXTBUILD_TMP')
100 if build_lib:
101 self.build_lib = build_lib
102 if build_tmp:
103 self.build_temp = build_tmp
104
105
106class InstallLib(_install_lib):
107 """Custom install_lib command to set output directory."""
108
109 def __init__(self, *args, **kwargs):
110 self.build_dir = None
111 super().__init__(*args, **kwargs)
112
113 def finalize_options(self) -> None:
114 _install_lib.finalize_options(self)
115 build_lib = os.getenv('PYTHON_EXTBUILD_LIB')
116 if build_lib:
117 self.build_dir = build_lib
118
119 def run(self):
120 _install_lib.run(self)
121 srctree = os.getenv('srctree', '.')
122 src_perf = os.path.join(srctree, 'tools/perf')
123 shutil.copy2(os.path.join(src_perf, 'python/perf.pyi'), self.install_dir)
124
125
126def main() -> None:
127 """Main entry point for the setup script."""
128 cc_env = os.getenv("CC")
129 assert cc_env, "Environment variable CC not set"
130
131 # Safe parsing of CC environment variable which might contain options/quotes
132 cc_tokens = shlex.split(cc_env)
133 cc = cc_tokens[0]
134 cc_args = cc_tokens[1:]
135
136 # Run CC -v to check if it is clang.
137 try:
138 cc_info = subprocess.run(
139 [cc, "-v"], stderr=subprocess.PIPE, stdout=subprocess.DEVNULL, check=False
140 )
141 cc_is_clang = b"clang version" in cc_info.stderr
142 except OSError as e:
143 raise RuntimeError(f"Failed to execute compiler '{cc}': {e}") from e
144
145 srctree = os.getenv('srctree')
146 assert srctree, "Environment variable srctree, for the Linux sources, not set"
147 src_feature_tests = f'{srctree}/tools/build/feature'
148
149 if cc_is_clang:
150 filter_clang_options(cc, cc_args, src_feature_tests)
151
152 # switch off several checks (need to be at the end of cflags list)
153 cflags = [
154 '-fno-strict-aliasing',
155 '-Wno-write-strings',
156 '-Wno-unused-parameter',
157 '-Wno-redundant-decls'
158 ]
159 if cc_is_clang:
160 cflags += ["-Wno-unused-command-line-argument"]
161 if clang_has_option(
162 cc, cc_args, src_feature_tests, "-Wno-cast-function-type-mismatch"
163 ):
164 cflags += ["-Wno-cast-function-type-mismatch"]
165 else:
166 cflags += ['-Wno-cast-function-type']
167
168 # The python headers have mixed code with declarations (decls after asserts, for instance)
169 cflags += ["-Wno-declaration-after-statement"]
170
171 src_perf = f'{srctree}/tools/perf'
172
173 perf = Extension(
174 'perf',
175 sources=[os.path.join(src_perf, 'util/python.c')],
176 include_dirs=['util/include'],
177 extra_compile_args=cflags,
178 )
179
180 setup(
181 name='perf',
182 version='0.1',
183 description='Interface with the Linux profiling infrastructure',
184 author='Arnaldo Carvalho de Melo',
185 author_email='[email protected]',
186 license='GPLv2',
187 url='http://perf.wiki.kernel.org',
188 ext_modules=[perf],
189 cmdclass={'build_ext': BuildExt, 'install_lib': InstallLib},
190 )
191
192
193if __name__ == '__main__':
194 main()