cpython/Tools/scripts/ifdef.py at v3.6.15 · python/cpython · GitHub

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#! /usr/bin/env python3

# Selectively preprocess #ifdef / #ifndef statements.

# Usage:

# ifdef [-Dname] ... [-Uname] ... [file] ...

# This scans the file(s), looking for #ifdef and #ifndef preprocessor

# commands that test for one of the names mentioned in the -D and -U

# options. On standard output it writes a copy of the input file(s)

# minus those code sections that are suppressed by the selected

# combination of defined/undefined symbols. The #if(n)def/#else/#else

# lines themselves (if the #if(n)def tests for one of the mentioned

# names) are removed as well.

# Features: Arbitrary nesting of recognized and unrecognized

# preprocessor statements works correctly. Unrecognized #if* commands

# are left in place, so it will never remove too much, only too

# little. It does accept whitespace around the '#' character.

# Restrictions: There should be no comments or other symbols on the

# #if(n)def lines. The effect of #define/#undef commands in the input

# file or in included files is not taken into account. Tests using

# #if and the defined() pseudo function are not recognized. The #elif

# command is not recognized. Improperly nesting is not detected.

# Lines that look like preprocessor commands but which are actually

# part of comments or string literals will be mistaken for

# preprocessor commands.

import sys

import getopt

defs = []

undefs = []

def main():

opts, args = getopt.getopt(sys.argv[1:], 'D:U:')

for o, a in opts:

if o == '-D':

defs.append(a)

if o == '-U':

undefs.append(a)

if not args:

args = ['-']

for filename in args:

if filename == '-':

process(sys.stdin, sys.stdout)

else:

f = open(filename, 'r')

process(f, sys.stdout)

f.close()

def process(fpi, fpo):

keywords = ('if', 'ifdef', 'ifndef', 'else', 'endif')

ok = 1

stack = []

while 1:

line = fpi.readline()

if not line: break

while line[-2:] == '\\\n':

nextline = fpi.readline()

if not nextline: break

line = line + nextline

tmp = line.strip()

if tmp[:1] != '#':

if ok: fpo.write(line)

continue

tmp = tmp[1:].strip()

words = tmp.split()

keyword = words[0]

if keyword not in keywords:

if ok: fpo.write(line)

continue

if keyword in ('ifdef', 'ifndef') and len(words) == 2:

if keyword == 'ifdef':

ko = 1

else:

ko = 0

word = words[1]

if word in defs:

stack.append((ok, ko, word))

if not ko: ok = 0

elif word in undefs:

stack.append((ok, not ko, word))

if ko: ok = 0

else:

stack.append((ok, -1, word))

if ok: fpo.write(line)

elif keyword == 'if':

stack.append((ok, -1, ''))

if ok: fpo.write(line)

elif keyword == 'else' and stack:

s_ok, s_ko, s_word = stack[-1]

if s_ko < 0:

if ok: fpo.write(line)

else:

s_ko = not s_ko

ok = s_ok

if not s_ko: ok = 0

stack[-1] = s_ok, s_ko, s_word

elif keyword == 'endif' and stack:

s_ok, s_ko, s_word = stack[-1]

if s_ko < 0:

if ok: fpo.write(line)

del stack[-1]

ok = s_ok

else:

sys.stderr.write('Unknown keyword %s\n' % keyword)

if stack:

sys.stderr.write('stack: %s\n' % stack)

if __name__ == '__main__':

main()

cpython/Tools/scripts/ifdef.py at v3.6.15 · python/cpython · GitHub

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