regen_headers tiny tidying:

- regen.pl renamed as regen_lib.pl
- regen_headers.pl renamed as regen.pl
- added make target 'regen' (kept target 'regen_headers'
  for porters' brains' backward compatibility)
- regen.pl fancified a bit to display the names
  of the files that got changed by running the scripts

p4raw-id: //depot/perl@18851

11 files changed, 118 insertions, 77 deletions

diff --git a/MANIFEST b/MANIFEST
index 767b6dc20e..6fec033605 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -2369,8 +2369,8 @@ regcomp.c			Regular expression compiler
 regcomp.h			Private declarations for above
 regcomp.pl			Builder of regnodes.h
 regcomp.sym			Data for regnodes.h
-regen.pl			Common file routines for generator scripts
-regen_headers.pl		Run all scripts that (re)generate files
+regen.pl			Run all scripts that (re)generate files
+regen_lib.pl			Common file routines for generator scripts
 regexec.c			Regular expression evaluator
 regexp.h			Public declarations for the above
 regnodes.h			Description of nodes of RE engine
diff --git a/Makefile.SH b/Makefile.SH
index cd18ffb49f..23ebd77fa4 100644
--- a/Makefile.SH
+++ b/Makefile.SH
@@ -812,20 +812,20 @@ SYMH = perlvars.h intrpvar.h thrdvar.h
 CHMOD_W = chmod +w
 
 # The following files are generated automatically
-#	keywords.pl:	keywords.h
-#	opcode.pl:	opcode.h opnames.h pp_proto.h pp.sym
-# [* embed.pl needs pp.sym generated by opcode.pl! *]
-#	embed.pl:	proto.h embed.h embedvar.h global.sym
-#			perlapi.h perlapi.c pod/perlintern.pod
-#			pod/perlapi.pod
+#	autodoc.pl:	pod/perlapi.pod pod/perlintern.pod
 #	bytecode.pl:	ext/ByteLoader/byterun.h ext/ByteLoader/byterun.c
 #			ext/B/B/Asmdata.pm
+#	embed.pl:	proto.h embed.h embedvar.h global.sym
+#			perlapi.h perlapi.c 
+# [* embed.pl needs pp.sym generated by opcode.pl! *]
+#	keywords.pl:	keywords.h
+#	opcode.pl:	opcode.h opnames.h pp_proto.h pp.sym
 #	regcomp.pl:	regnodes.h
 #	warnings.pl:	warnings.h lib/warnings.pm
 # The correct versions should be already supplied with the perl kit,
 # in case you don't have perl available.
 # To force them to be regenerated, run
-#       perl regen_headers.pl
+#       perl regen.pl
 # with your existing copy of perl
 # (make regen_headers is kept for backwards compatibility)
 
@@ -838,13 +838,13 @@ AUTOGEN_FILES = keywords.h opcode.h opnames.h pp_proto.h pp.sym proto.h \
 
 .PHONY: regen_headers regen_pods regen_all
 
-regen_headers:	FORCE
-	-perl regen_headers.pl
+regen regen_headers:	FORCE
+	-perl regen.pl
 
 regen_pods:	FORCE
 	-cd pod; $(LDLIBPTH) $(MAKE) regen_pods
 
-regen_all: $(PERLYVMS) regen_headers regen_pods
+regen_all: $(PERLYVMS) regen regen_pods
 
 # Extensions:
 # Names added to $(dynamic_ext) or $(static_ext) or $(nonxs_ext) will
diff --git a/autodoc.pl b/autodoc.pl
index 2044dab5c1..503fc5e104 100644
--- a/autodoc.pl
+++ b/autodoc.pl
@@ -5,7 +5,7 @@ require 5.003;	# keep this compatible, an old perl is all we may have before
 
 BEGIN {
   push @INC, 'lib';
-  require 'regen.pl';
+  require 'regen_lib.pl';
 }	# glob() below requires File::Glob
 
 
diff --git a/bytecode.pl b/bytecode.pl
index 0c921d4d1a..569d28e9fc 100644
--- a/bytecode.pl
+++ b/bytecode.pl
@@ -1,6 +1,6 @@
 BEGIN {
   push @INC, './lib';
-  require 'regen.pl';
+  require 'regen_lib.pl';
 }
 use strict;
 my %alias_to = (
diff --git a/embed.pl b/embed.pl
index 8a1f2a0268..a8a2da727e 100755
--- a/embed.pl
+++ b/embed.pl
@@ -5,7 +5,7 @@ require 5.003;	# keep this compatible, an old perl is all we may have before
 
 BEGIN {
     # Get function prototypes
-    require 'regen.pl';
+    require 'regen_lib.pl';
 }
 
 #
diff --git a/keywords.pl b/keywords.pl
index c804620cf8..09e8debb97 100755
--- a/keywords.pl
+++ b/keywords.pl
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 
-require 'regen.pl';
+require 'regen_lib.pl';
 safer_unlink ("keywords.h");
 open(KW, ">keywords.h") || die "Can't create keywords.h: $!\n";
 select KW;
diff --git a/opcode.pl b/opcode.pl
index 09c20b1392..4035cc6002 100755
--- a/opcode.pl
+++ b/opcode.pl
@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 BEGIN {
     # Get function prototypes
-    require 'regen.pl';
+    require 'regen_lib.pl';
 }
 
 $opcode_new = 'opcode.h-new';
diff --git a/regcomp.pl b/regcomp.pl
index 225882a576..1809da3b25 100644
--- a/regcomp.pl
+++ b/regcomp.pl
@@ -1,6 +1,6 @@
 BEGIN {
     # Get function prototypes
-    require 'regen.pl';
+    require 'regen_lib.pl';
 }
 #use Fatal qw(open close rename chmod unlink);
 open DESC, 'regcomp.sym';
diff --git a/regen.pl b/regen.pl
index 1c830a2cdc..5d4c1df2b3 100644
--- a/regen.pl
+++ b/regen.pl
@@ -1,45 +1,64 @@
 #!/usr/bin/perl -w
-use strict;
-use vars qw($Is_W32 $Is_OS2 $Is_Cygwin $Is_NetWare $Needs_Write);
-use Config; # Remember, this is running using an existing perl
-
-# Common functions needed by the regen scripts
-
-$Is_W32 = $^O eq 'MSWin32';
-$Is_OS2 = $^O eq 'os2';
-$Is_Cygwin = $^O eq 'cygwin';
-$Is_NetWare = $Config{osname} eq 'NetWare';
-if ($Is_NetWare) {
-  $Is_W32 = 0;
-}
+require 5.003;	# keep this compatible, an old perl is all we may have before
+                # we build the new one
 
-$Needs_Write = $Is_OS2 || $Is_W32 || $Is_Cygwin || $Is_NetWare;
+# The idea is to move the regen_headers target out of the Makefile so that
+# it is possible to rebuild the headers before the Makefile is available.
+# (and the Makefile is unavailable until after Configure is run, and we may
+# wish to make a clean source tree but with current headers without running
+# anything else.
 
-sub safer_unlink {
-  my @names = @_;
-  my $cnt = 0;
+use strict;
+my $perl = $^X;
 
-  my $name;
-  foreach $name (@names) {
-    next unless -e $name;
-    chmod 0777, $name if $Needs_Write;
-    ( CORE::unlink($name) and ++$cnt
-      or warn "Couldn't unlink $name: $!\n" );
-  }
-  return $cnt;
-}
+require 'regen_lib.pl';
+# keep warnings.pl in sync with the CPAN distribution by not requiring core
+# changes
+safer_unlink ("warnings.h", "lib/warnings.pm");
 
-sub safer_rename_silent {
-  my ($from, $to) = @_;
+my %gen = (
+	   'autodoc.pl'  => [qw[pod/perlapi.pod pod/perlintern.pod]],
+	   'bytecode.pl' => [qw[ext/ByteLoader/byterun.h
+				ext/ByteLoader/byterun.c
+				ext/B/B/Asmdata.pm]],
+	   'embed.pl'    => [qw[proto.h embed.h embedvar.h global.sym
+				perlapi.h perlapi.c]],
+	   'keywords.pl' => [qw[keywords.h]],
+	   'opcode.pl'   => [qw[opcode.h opnames.h pp_proto.h pp.sym]],
+	   'regcomp.pl'  => [qw[regnodes.h]],
+	   'warnings.pl' => [qw[warnings.h lib/warnings.pm]]
+	   );
 
-  # Some dosish systems can't rename over an existing file:
-  safer_unlink $to;
-  chmod 0600, $from if $Needs_Write;
-  rename $from, $to;
+sub do_cksum {
+    my $pl = shift;
+    my %cksum;
+    for my $f (@{ $gen{$pl} }) {
+	local *FH;
+	if (open(FH, $f)) {
+	    local $/;
+	    $cksum{$f} = unpack("%32C*", <FH>);
+	    close FH;
+	} else {
+	    warn "$0: $f: $!\n";
+	}
+    }
+    return %cksum;
 }
 
-sub safer_rename {
-  my ($from, $to) = @_;
-  safer_rename_silent($from, $to) or die "renaming $from to $to: $!";
+foreach my $pl (qw (keywords.pl opcode.pl embed.pl bytecode.pl
+		    regcomp.pl warnings.pl autodoc.pl)) {
+  print "$^X $pl\n";
+  my %cksum0;
+  %cksum0 = do_cksum($pl) unless $pl eq 'warnings.pl'; # the files were removed
+  system "$^X $pl";
+  next if $pl eq 'warnings.pl'; # the files were removed
+  my %cksum1 = do_cksum($pl);
+  my @chg;
+  for my $f (@{ $gen{$pl} }) {
+      push(@chg, $f)
+	  if !defined($cksum0{$f}) ||
+	     !defined($cksum1{$f}) ||
+	     $cksum0{$f} ne $cksum1{$f};
+  }
+  print "Changed: @chg\n" if @chg;
 }
-1;
diff --git a/regen_headers.pl b/regen_headers.pl
deleted file mode 100644
index 2f405bb7ce..0000000000
--- a/regen_headers.pl
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/usr/bin/perl -w
-require 5.003;	# keep this compatible, an old perl is all we may have before
-                # we build the new one
-
-# The idea is to move the regen_headers target out of the Makefile so that
-# it is possible to rebuild the headers before the Makefile is available.
-# (and the Makefile is unavailable until after Configure is run, and we may
-# wish to make a clean source tree but with current headers without running
-# anything else.
-
-use strict;
-my $perl = $^X;
-
-require 'regen.pl';
-# keep warnings.pl in sync with the CPAN distribution by not requiring core
-# changes
-safer_unlink ("warnings.h", "lib/warnings.pm");
-
-foreach (qw (keywords.pl opcode.pl embed.pl bytecode.pl regcomp.pl
-	     warnings.pl autodoc.pl)) {
-  print "$^X $_\n";
-  system "$^X $_";
-}
diff --git a/regen_lib.pl b/regen_lib.pl
new file mode 100644
index 0000000000..1c830a2cdc
--- /dev/null
+++ b/regen_lib.pl
@@ -0,0 +1,45 @@
+#!/usr/bin/perl -w
+use strict;
+use vars qw($Is_W32 $Is_OS2 $Is_Cygwin $Is_NetWare $Needs_Write);
+use Config; # Remember, this is running using an existing perl
+
+# Common functions needed by the regen scripts
+
+$Is_W32 = $^O eq 'MSWin32';
+$Is_OS2 = $^O eq 'os2';
+$Is_Cygwin = $^O eq 'cygwin';
+$Is_NetWare = $Config{osname} eq 'NetWare';
+if ($Is_NetWare) {
+  $Is_W32 = 0;
+}
+
+$Needs_Write = $Is_OS2 || $Is_W32 || $Is_Cygwin || $Is_NetWare;
+
+sub safer_unlink {
+  my @names = @_;
+  my $cnt = 0;
+
+  my $name;
+  foreach $name (@names) {
+    next unless -e $name;
+    chmod 0777, $name if $Needs_Write;
+    ( CORE::unlink($name) and ++$cnt
+      or warn "Couldn't unlink $name: $!\n" );
+  }
+  return $cnt;
+}
+
+sub safer_rename_silent {
+  my ($from, $to) = @_;
+
+  # Some dosish systems can't rename over an existing file:
+  safer_unlink $to;
+  chmod 0600, $from if $Needs_Write;
+  rename $from, $to;
+}
+
+sub safer_rename {
+  my ($from, $to) = @_;
+  safer_rename_silent($from, $to) or die "renaming $from to $to: $!";
+}
+1;