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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,107 @@ | ||
| """ | ||
| Utility functions for building the FFI. | ||
| """ | ||
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| import subprocess | ||
| import os | ||
| import re | ||
| import tempfile | ||
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| class FFIBuildException(Exception): | ||
| """Generic exception for errors occuring during the CFFI build.""" | ||
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| def get_include_flags(): | ||
| """ | ||
| Obtains libcpuid include flags via pkg-config. | ||
| """ | ||
| try: | ||
| cflags = ( | ||
| subprocess.check_output(["pkg-config", "libcpuid", "--cflags-only-I"]) | ||
| .decode() | ||
| .strip() | ||
| .split() | ||
| ) | ||
| return cflags | ||
| except subprocess.CalledProcessError as e: | ||
| if e.returncode == 127: | ||
| raise FFIBuildException( | ||
| "The pkg-config command is necessary to build python-libcpuid." | ||
| ) from e | ||
| if e.returncode == 1: | ||
| raise FFIBuildException( | ||
| "The libcpuid C library (devel) was not found." | ||
| ) from e | ||
| raise FFIBuildException("Error looking for the libcpuid library") from e | ||
|
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| def find_header_file(include_flags): | ||
| """ | ||
| Obtains main libcpuid header file location from include flags. | ||
| """ | ||
| header_path = None # pylint: disable=invalid-name | ||
| for cflag in include_flags: | ||
| header_candidate = os.path.join(cflag[2:], "libcpuid.h") | ||
| if os.path.isfile(header_candidate): | ||
| header_path = header_candidate | ||
| break | ||
| if header_path is None: | ||
| raise FFIBuildException("Could not find header file of the libcpuid library.") | ||
| return header_path | ||
|
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| def preprocess_header(header_path): | ||
| """ | ||
| Preprocesses the header file (python-cffi only accepts preprocessed C definitions) | ||
| at the given path and returns it as a string. | ||
| """ | ||
| try: | ||
| return subprocess.check_output( | ||
| ["gcc", "-U __GNUC__", "-E", header_path] | ||
| ).decode() | ||
| except subprocess.CalledProcessError as e: | ||
| if e.returncode == 127: | ||
| raise FFIBuildException( | ||
| "The gcc compiler is necessary to build python-libcpuid." | ||
| ) from e | ||
| raise FFIBuildException( | ||
| f"Error preprocessing the libcpuid header file: {e.stderr}" | ||
| ) from e | ||
|
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|
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| def _get_sizeof_eval_source(sizeof): | ||
| return f""" | ||
| #include <libcpuid.h> | ||
| #include <stdio.h> | ||
| int main() {{ | ||
| printf("%d", {sizeof}); | ||
| return 0; | ||
| }} | ||
| """ | ||
|
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| def eval_sizeofs(header, cflags): | ||
| """ | ||
| Evaluates each sizeof found in the given C header and replaces all | ||
| occurences of the sizeof with its computed value. | ||
| """ | ||
| sizeofs = set(re.findall(r"sizeof\([^\)]*\)", header)) | ||
| tmp_dir = tempfile.mkdtemp() | ||
| c_program_path = os.path.join(tmp_dir, "sizeof.c") | ||
| executable_path = os.path.join(tmp_dir, "sizeof") | ||
|
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||
| for sizeof in sizeofs: | ||
| with open(c_program_path, "w", encoding="UTF-8") as c_program_file: | ||
| c_program_file.write(_get_sizeof_eval_source(sizeof)) | ||
| subprocess.check_call( | ||
| ["gcc", c_program_path, *cflags, "-o", executable_path] | ||
| ) | ||
| size = subprocess.check_output([executable_path]).decode() | ||
| header = header.replace(sizeof, size) | ||
|
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| os.remove(c_program_path) | ||
| os.remove(executable_path) | ||
| os.rmdir(tmp_dir) | ||
| return header |