1#!perl -w
2use strict;
3
4use Pod::Usage;
5use Getopt::Std;
6$Getopt::Std::STANDARD_HELP_VERSION = 1;
7
8my $trysource = "try.c";
9my $tryout = "try.i";
10
11getopts('fF:ekvI:', \my %opt) or pod2usage();
12
13my($expr, @headers) = @ARGV ? splice @ARGV : "-";
14
15pod2usage "-f and -F <tool> are exclusive\n" if $opt{f} and $opt{F};
16
17foreach($trysource, $tryout) {
18    unlink $_ if $opt{e};
19    die "You already have a $_" if -e $_;
20}
21
22if ($expr eq '-') {
23    warn "reading from stdin...\n";
24    $expr = do { local $/; <> };
25}
26
27my($macro, $args) = $expr =~ /^\s*(\w+)((?:\s*\(.*\))?)\s*;?\s*$/s
28    or pod2usage "$expr doesn't look like a macro-name or macro-expression to me";
29
30if (!(@ARGV = @headers)) {
31    open my $fh, '<', 'MANIFEST' or die "Can't open MANIFEST: $!";
32    while (<$fh>) {
33	push @ARGV, $1 if m!^([^/]+\.h)\t!;
34    }
35    push @ARGV, 'config.h' if -f 'config.h';
36}
37
38my $header;
39while (<>) {
40    next unless /^#\s*define\s+$macro\b/;
41    my ($def_args) = /^#\s*define\s+$macro\(([^)]*)\)/;
42    if (defined $def_args && !$args) {
43	my @args = split ',', $def_args;
44	print "# macro: $macro args: @args in $_\n" if $opt{v};
45	my $argname = "A0";
46	$args = '(' . join (', ', map {$argname++} 1..@args) . ')';
47    }
48    $header = $ARGV;
49    last;
50}
51die "$macro not found\n" unless defined $header;
52
53open my $out, '>', $trysource or die "Can't open $trysource: $!";
54
55my $sentinel = "$macro expands to";
56
57print $out <<"EOF";
58#include "EXTERN.h"
59#include "perl.h"
60EOF
61
62print $out qq{#include "$header"\n}
63    unless $header eq 'perl.h' or $header eq 'EXTERN.h';
64
65print $out <<"EOF";
66#line 4 "$sentinel"
67$macro$args
68EOF
69
70close $out or die "Can't close $trysource: $!";
71
72print "doing: make $tryout\n" if $opt{v};
73system "make $tryout" and die;
74
75# if user wants 'indent' formatting ..
76my $out_fh;
77
78if ($opt{f} || $opt{F}) {
79    # a: indent is a well behaved filter when given 0 arguments, reading from
80    #    stdin and writing to stdout
81    # b: all our braces should be balanced, indented back to column 0, in the
82    #    headers, hence everything before our #line directive can be ignored
83    #
84    # We can take advantage of this to reduce the work to indent.
85
86    my $indent_command = $opt{f} ? 'indent' : $opt{F};
87
88    if (defined $opt{I}) {
89	$indent_command .= " $opt{I}";
90    }
91    open $out_fh, '|-', $indent_command or die $?;
92} else {
93    $out_fh = \*STDOUT;
94}
95
96open my $fh, '<', $tryout or die "Can't open $tryout: $!";
97
98while (<$fh>) {
99    print $out_fh $_ if /$sentinel/o .. 1;
100}
101
102unless ($opt{k}) {
103    foreach($trysource, $tryout) {
104	die "Can't unlink $_" unless unlink $_;
105    }
106}
107
108__END__
109
110=head1 NAME
111
112expand-macro.pl - expand C macros using the C preprocessor
113
114=head1 SYNOPSIS
115
116  expand-macro.pl [options] [ < macro-name | macro-expression | - > [headers] ]
117
118  options:
119    -f		use 'indent' to format output
120    -F	<tool>	use <tool> to format output  (instead of -f)
121    -e		erase try.[ic] instead of failing when they're present (errdetect)
122    -k		keep them after generating (for handy inspection)
123    -v		verbose
124    -I <indent-opts>	passed into indent
125
126=cut
127