forked from anrieff/libcpuid
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
3 changed files
with
119 additions
and
63 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,107 @@ | ||
| """ | ||
| Utility functions for building the FFI. | ||
| """ | ||
|
|
||
| import subprocess | ||
| import os | ||
| import re | ||
| import tempfile | ||
|
|
||
|
|
||
| class FFIBuildException(Exception): | ||
| """Generic exception for errors occuring during the CFFI build.""" | ||
|
|
||
|
|
||
| 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 | ||
|
|
||
|
|
||
| def find_header_file(): | ||
| """ | ||
| Obtains libcpuid header file location via pkg-config. | ||
| """ | ||
| header_path = None # pylint: disable=invalid-name | ||
| for cflag in _get_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 | ||
|
|
||
|
|
||
| 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 | ||
|
|
||
|
|
||
| def _get_sizeof_eval_source(sizeof): | ||
| return f""" | ||
| #include <libcpuid.h> | ||
| #include <stdio.h> | ||
| int main() {{ | ||
| printf("%d", {sizeof}); | ||
| return 0; | ||
| }} | ||
| """ | ||
|
|
||
|
|
||
| def eval_sizeofs(header): | ||
| """ | ||
| 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") | ||
|
|
||
| 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, *_get_include_flags(), "-o", executable_path] | ||
| ) | ||
| size = subprocess.check_output([executable_path]).decode() | ||
| header = header.replace(sizeof, size) | ||
|
|
||
| os.remove(c_program_path) | ||
| os.remove(executable_path) | ||
| os.rmdir(tmp_dir) | ||
| return header |