1#!perl -w
2use strict;
3
4use Pod::Usage;
5use Getopt::Std;
6use Config;
7$Getopt::Std::STANDARD_HELP_VERSION = 1;
8
9my $trysource = "try.c";
10my $tryout = "try.i";
11
12getopts('fF:ekvI:X', \my %opt) or pod2usage();
13
14my($expr, @headers) = @ARGV ? splice @ARGV : "-";
15
16pod2usage "-f and -F <tool> are exclusive\n" if $opt{f} and $opt{F};
17
18foreach($trysource, $tryout) {
19    unlink $_ if $opt{e};
20    die "You already have a $_" if -e $_;
21}
22
23if ($expr eq '-') {
24    warn "reading from stdin...\n";
25    $expr = do { local $/; <> };
26}
27
28my($macro, $args) = $expr =~ /^\s*(\w+)((?:\s*\(.*\))?)\s*;?\s*$/s
29    or pod2usage "$expr doesn't look like a macro-name or macro-expression to me";
30
31if (!(@ARGV = @headers)) {
32    open my $fh, '<', 'MANIFEST' or die "Can't open MANIFEST: $!";
33    while (<$fh>) {
34	push @ARGV, $1 if m!^([^/]+\.h)\t!;
35    }
36    push @ARGV, 'config.h' if -f 'config.h';
37}
38
39my $header;
40while (<>) {
41    next unless /^#\s*define\s+$macro\b/;
42    my ($def_args) = /^#\s*define\s+$macro\(([^)]*)\)/;
43    if (defined $def_args && !$args) {
44	my @args = split ',', $def_args;
45	print "# macro: $macro args: @args in $_\n" if $opt{v};
46	my $argname = "A0";
47	$args = '(' . join (', ', map {$argname++} 1..@args) . ')';
48    }
49    $header = $ARGV;
50    last;
51}
52die "$macro not found\n" unless defined $header;
53
54if ($^O =~ /MSWin(32|64)/) {
55    # The Win32 (and Win64) build process expects to be run from
56    # bleadperl/Win32
57    chdir "Win32"
58	or die "Couldn't chdir to win32: $!";
59};
60
61open my $out, '>', $trysource or die "Can't open $trysource: $!";
62
63my $sentinel = "$macro expands to";
64
65# These two are included from perl.h, and perl.h sometimes redefines their
66# macros. So no need to include them.
67my %done_header = ('embed.h' => 1, 'embedvar.h' => 1);
68
69sub do_header {
70    my $header = shift;
71    return if $done_header{$header}++;
72    print $out qq{#include "$header"\n};
73}
74
75print $out <<'EOF' if $opt{X};
76/* Need to do this like this, as cflags.sh sets it for us come what may.  */
77#undef PERL_CORE
78
79EOF
80
81do_header('EXTERN.h');
82do_header('perl.h');
83do_header($header);
84do_header('XSUB.h') if $opt{X};
85
86print $out <<"EOF";
87#line 4 "$sentinel"
88$macro$args
89EOF
90
91close $out or die "Can't close $trysource: $!";
92
93print "doing: $Config{make} $tryout\n" if $opt{v};
94my $cmd = "$Config{make} $tryout";
95system( $cmd ) == 0
96    or die "Couldn't launch [$cmd]: $! / $?";
97
98# if user wants 'indent' formatting ..
99my $out_fh;
100
101if ($opt{f} || $opt{F}) {
102    # a: indent is a well behaved filter when given 0 arguments, reading from
103    #    stdin and writing to stdout
104    # b: all our braces should be balanced, indented back to column 0, in the
105    #    headers, hence everything before our #line directive can be ignored
106    #
107    # We can take advantage of this to reduce the work to indent.
108
109    my $indent_command = $opt{f} ? 'indent' : $opt{F};
110
111    if (defined $opt{I}) {
112	$indent_command .= " $opt{I}";
113    }
114    open $out_fh, '|-', $indent_command or die $?;
115} else {
116    $out_fh = \*STDOUT;
117}
118
119{
120    open my $fh, '<', $tryout or die "Can't open $tryout: $!";
121
122    while (<$fh>) {
123	print $out_fh $_ if /$sentinel/o .. 1;
124    }
125};
126
127unless ($opt{k}) {
128    foreach($trysource, $tryout) {
129	die "Can't unlink $_: $!" unless unlink $_;
130    }
131}
132
133__END__
134
135=head1 NAME
136
137expand-macro.pl - expand C macros using the C preprocessor
138
139=head1 SYNOPSIS
140
141  expand-macro.pl [options] [ < macro-name | macro-expression | - > [headers] ]
142
143  options:
144    -f		use 'indent' to format output
145    -F	<tool>	use <tool> to format output  (instead of -f)
146    -e		erase try.[ic] instead of failing when they're present (errdetect)
147    -k		keep them after generating (for handy inspection)
148    -v		verbose
149    -I <indent-opts>	passed into indent
150    -X		include "XSUB.h" (and undefine PERL_CORE)
151
152=cut
153