regexec.c: Add to comment

[perl5.git] / regen_perly.pl

diff --git a/regen_perly.pl b/regen_perly.pl
index 859495f..e4de1a0 100644 (file)
--- a/regen_perly.pl
+++ b/regen_perly.pl
@@ -34,6 +34,8 @@ sub usage { die "usage: $0 [ -b bison_executable ] [ file.y ]\n" }
 use warnings;
 use strict;
 
+BEGIN { require 'regen/regen_lib.pl'; }
+
 my $bison = 'bison';
 
 if (@ARGV >= 2 and $ARGV[0] eq '-b') {
@@ -50,6 +52,9 @@ usage unless @ARGV==0 && $y_file =~ /\.y$/;
 (my $tab_file  = $y_file) =~ s/\.y$/.tab/;
 (my $tmpc_file = $y_file) =~ s/\.y$/tmp.c/;
 (my $tmph_file = $y_file) =~ s/\.y$/tmp.h/;
+my $new_h_file = "$h_file-new";
+my $new_act_file = "$act_file-new";
+my $new_tab_file = "$tab_file-new";
 
 # the yytranslate[] table generated by bison is ASCII/EBCDIC sensitive
 
@@ -61,11 +66,15 @@ die "$0: must be run on an ASCII system\n" unless ord 'A' == 65;
 #    this; 1.35+ does
 #  * Must produce output which is extractable by the regexes below
 #  * Must produce the right values.
-# These last two contstraints  may well be met by earlier versions, but
+# These last two constraints  may well be met by earlier versions, but
 # I simply haven't tested them yet. If it works for you, then modify
 # the test below to allow that version too. DAPM Feb 04.
 
 my $version = `$bison -V`;
+unless ($version) { die <<EOF; }
+Could not find a version of bison in your path. Please install bison.
+EOF
+
 unless ($version =~ /\b(1\.875[a-z]?|2\.[0134])\b/) { die <<EOF; }
 
 You have the wrong version of bison in your path; currently 1.875
@@ -90,17 +99,17 @@ my ($actlines, $tablines) = extract($clines);
 
 $tablines .= make_type_tab($y_file, $tablines);
 
-chmod 0644, $act_file;
-open ACTFILE, ">$act_file" or die "can't open $act_file: $!\n";
+chmod 0644, $new_act_file;
+open ACTFILE, ">$new_act_file" or die "can't open $new_act_file: $!\n";
 print ACTFILE $actlines;
 close ACTFILE;
-chmod 0444, $act_file;
+chmod 0444, $new_act_file;
 
-chmod 0644, $tab_file;
-open TABFILE, ">$tab_file" or die "can't open $tab_file: $!\n";
+chmod 0644, $new_tab_file;
+open TABFILE, ">$new_tab_file" or die "can't open $new_tab_file: $!\n";
 print TABFILE $tablines;
 close TABFILE;
-chmod 0444, $tab_file;
+chmod 0444, $new_tab_file;
 
 unlink $tmpc_file;
 
@@ -109,8 +118,8 @@ unlink $tmpc_file;
 # C<#line 188 "perlytmp.h"> gets picked up by make depend, so remove them.
 
 open TMPH_FILE, $tmph_file or die "Can't open $tmph_file: $!\n";
-chmod 0644, $h_file;
-open H_FILE, ">$h_file" or die "Can't open $h_file: $!\n";
+chmod 0644, $new_h_file;
+open H_FILE, ">$new_h_file" or die "Can't open $new_h_file: $!\n";
 my $endcore_done = 0;
 # Token macros need to be generated manually on bison 2.4
 my $gather_tokens = ($version =~ /\b2\.4\b/ ? undef : 0);
@@ -139,10 +148,12 @@ while (<TMPH_FILE>) {
 }
 close TMPH_FILE;
 close H_FILE;
-chmod 0444, $h_file;
+chmod 0444, $new_h_file;
 unlink $tmph_file;
 
-print "rebuilt:  $h_file $tab_file $act_file\n";
+rename_if_different($new_h_file, $h_file);
+rename_if_different($new_tab_file, $tab_file);
+rename_if_different($new_act_file, $act_file);
 
 exit 0;