mirror of
https://github.com/freebsd/freebsd-src
synced 2024-07-22 02:37:15 +00:00
fb3ef04d20
git-subtree-dir: contrib/unifdef git-subtree-mainline:3b7ffacdeegit-subtree-split:0da4488583
43 lines
899 B
Perl
Executable file
43 lines
899 B
Perl
Executable file
#!/usr/bin/perl
|
|
|
|
use warnings;
|
|
use strict;
|
|
|
|
if (@ARGV != 2) {
|
|
die <<END;
|
|
usage: ifdef-how <file> <line>
|
|
|
|
Print the sequence of preprocessor conditionals which lead to the
|
|
given line being retained after preprocessing. There is no output
|
|
if the line is always retained. Conditionals that must be true are
|
|
printed verbatim; conditionals that musy be false have their
|
|
preprocessor keyword prefixed with NOT.
|
|
|
|
Warning: this program does not parse comments or strings, so it will
|
|
not handle tricky code correctly.
|
|
END
|
|
}
|
|
|
|
my $file = shift;
|
|
my $line = shift;
|
|
|
|
open my $fh, '<', $file
|
|
or die "ifdef-how: open $file: $!\n";
|
|
|
|
my @stack;
|
|
while (<$fh>) {
|
|
last if $. == $line;
|
|
if (m{^\s*#\s*(if|ifdef|ifndef)\b}) {
|
|
push @stack, $_;
|
|
}
|
|
if (m{^\s*#\s*(elif|else)\b}) {
|
|
$stack[-1] =~ s{^(\s*#\s*)(?!NOT)\b}{${1}NOT}gm;
|
|
$stack[-1] .= $_;
|
|
}
|
|
if (m{^\s*#\s*endif\b}) {
|
|
pop @stack;
|
|
}
|
|
}
|
|
|
|
print @stack;
|