3 # Selectively preprocess #ifdef / #ifndef statements.
5 # ifdef [-Dname] ... [-Uname] ... [file] ...
7 # This scans the file(s), looking for #ifdef and #ifndef preprocessor
8 # commands that test for one of the names mentioned in the -D and -U
9 # options. On standard output it writes a copy of the input file(s)
10 # minus those code sections that are suppressed by the selected
11 # combination of defined/undefined symbols. The #if(n)def/#else/#else
12 # lines themselfs (if the #if(n)def tests for one of the mentioned
13 # names) are removed as well.
15 # Features: Arbitrary nesting of recognized and unrecognized
16 # preprocesor statements works correctly. Unrecognized #if* commands
17 # are left in place, so it will never remove too much, only too
18 # little. It does accept whitespace around the '#' character.
20 # Restrictions: There should be no comments or other symbols on the
21 # #if(n)def lines. The effect of #define/#undef commands in the input
22 # file or in included files is not taken into account. Tests using
23 # #if and the defined() pseudo function are not recognized. The #elif
24 # command is not recognized. Improperly nesting is not detected.
25 # Lines that look like preprocessor commands but which are actually
26 # part of comments or string literals will be mistaken for
27 # preprocessor commands.
36 opts, args = getopt.getopt(sys.argv[1:], 'D:U:')
46 process(sys.stdin, sys.stdout)
48 f = open(filename, 'r')
49 process(f, sys.stdout)
52 def process(fpi, fpo):
53 keywords = ('if', 'ifdef', 'ifndef', 'else', 'endif')
59 while line[-2:] == '\\\n':
60 nextline = fpi.readline()
61 if not nextline: break
62 line = line + nextline
65 if ok: fpo.write(line)
70 if keyword not in keywords:
71 if ok: fpo.write(line)
73 if keyword in ('ifdef', 'ifndef') and len(words) == 2:
74 if keyword == 'ifdef':
80 stack.append((ok, ko, word))
83 stack.append((ok, not ko, word))
86 stack.append((ok, -1, word))
87 if ok: fpo.write(line)
89 stack.append((ok, -1, ''))
90 if ok: fpo.write(line)
91 elif keyword == 'else' and stack:
92 s_ok, s_ko, s_word = stack[-1]
94 if ok: fpo.write(line)
99 stack[-1] = s_ok, s_ko, s_word
100 elif keyword == 'endif' and stack:
101 s_ok, s_ko, s_word = stack[-1]
103 if ok: fpo.write(line)
107 sys.stderr.write('Unknown keyword %s\n' % keyword)
109 sys.stderr.write('stack: %s\n' % stack)
111 if __name__ == '__main__':