glibc/scripts/gen-as-const.py

121 lines
4.5 KiB
Python

#!/usr/bin/python3
# Produce headers of assembly constants from C expressions.
# Copyright (C) 2018-2022 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
#
# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# The GNU C Library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <https://www.gnu.org/licenses/>.
# The input to this script looks like:
# #cpp-directive ...
# NAME1
# NAME2 expression ...
# A line giving just a name implies an expression consisting of just that name.
import argparse
import glibcextract
def gen_test(sym_data):
"""Generate a test for the values of some C constants.
The first argument is as for glibcextract.compute_c_consts.
"""
out_lines = []
for arg in sym_data:
if isinstance(arg, str):
if arg == 'START':
out_lines.append('#include <stdint.h>\n'
'#include <stdio.h>\n'
'#include <bits/wordsize.h>\n'
'#if __WORDSIZE == 64\n'
'typedef uint64_t c_t;\n'
'# define U(n) UINT64_C (n)\n'
'#else\n'
'typedef uint32_t c_t;\n'
'# define U(n) UINT32_C (n)\n'
'#endif\n'
'static int\n'
'do_test (void)\n'
'{\n'
# Compilation test only, using static
# assertions.
' return 0;\n'
'}\n'
'#include <support/test-driver.c>')
else:
out_lines.append(arg)
continue
name = arg[0]
value = arg[1]
out_lines.append('_Static_assert (U (asconst_%s) == (c_t) (%s), '
'"value of %s");'
% (name, value, name))
return '\n'.join(out_lines)
def main():
"""The main entry point."""
parser = argparse.ArgumentParser(
description='Produce headers of assembly constants.')
parser.add_argument('--cc', metavar='CC',
help='C compiler (including options) to use')
parser.add_argument('--test', action='store_true',
help='Generate test case instead of header')
parser.add_argument('--python', action='store_true',
help='Generate Python file instead of header')
parser.add_argument('sym_file',
help='.sym file to process')
args = parser.parse_args()
sym_data = []
with open(args.sym_file, 'r') as sym_file:
started = False
for line in sym_file:
line = line.strip()
if line == '':
continue
# Pass preprocessor directives through.
if line.startswith('#'):
sym_data.append(line)
continue
words = line.split(maxsplit=1)
if not started:
sym_data.append('START')
started = True
# Separator.
if words[0] == '--':
continue
name = words[0]
value = words[1] if len(words) > 1 else words[0]
sym_data.append((name, value))
if not started:
sym_data.append('START')
if args.test:
print(gen_test(sym_data))
elif args.python:
consts = glibcextract.compute_c_consts(sym_data, args.cc)
print('# GENERATED FILE\n'
'\n'
'# Constant definitions.\n'
'# See gen-as-const.py for details.\n')
print(''.join('%s = %s\n' % c for c in sorted(consts.items())), end='')
else:
consts = glibcextract.compute_c_consts(sym_data, args.cc)
print(''.join('#define %s %s\n' % c for c in sorted(consts.items())), end='')
if __name__ == '__main__':
main()