From 36c5702d56bc124a088b37fd8d1308f9c2cbe17a Mon Sep 17 00:00:00 2001
From: Alexandre Duret-Lutz <adl@gnu.org>
Date: Thu, 5 Aug 2004 22:30:41 +0000
Subject: [PATCH] Speed up make_paragraphs. * automake.in (handle_languages):
 Always define SUBDIROBJ, DERIVED-EXT, and DIST_SOURCE, because the new
 transform() will abort on unknown tokens. (transform): Rewrite with different
 semantics. (make_paragraphs): Make a single pass over the paragraph to
 transform all template tokens instead of doing as much passes as possible
 token.

---
 ChangeLog   |  9 +++++
 automake.in | 99 +++++++++++++++++++++++++++++------------------------
 2 files changed, 63 insertions(+), 45 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a72aa0670..41b19db01 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2004-08-05  Alexandre Duret-Lutz  <adl@gnu.org>
 
+	Speed up make_paragraphs.
+	* automake.in (handle_languages): Always define SUBDIROBJ,
+	DERIVED-EXT, and DIST_SOURCE, because the new transform() will
+	abort on unknown tokens.
+	(transform): Rewrite with different semantics.
+	(make_paragraphs): Make a single pass over the paragraph to
+	transform all template tokens instead of doing as much passes as
+	possible token.
+
 	* automake.in ($libtool_new_api): New variable.
 	(handle_libtool): Do not libtool's aux files if $libtool_new_api.
 	(scan_autoconf_traces) <LT_SUPPORTED_TAG>: Set $libtool_new_api.
diff --git a/automake.in b/automake.in
index 30f997996..0d8a52f37 100755
--- a/automake.in
+++ b/automake.in
@@ -1143,7 +1143,13 @@ sub handle_languages
 			 'FASTDEP' => $FASTDEP,
 			 '-c'      => $lang->compile_flag || '',
 			 'MORE-THAN-ONE'
-			           => (count_files_for_language ($lang->name) > 1));
+			           => (count_files_for_language ($lang->name) > 1),
+			 # These are not used, but they need to be defined
+			 # so &transform do not complain.
+			 SUBDIROBJ     => 0,
+			 'DERIVED-EXT' => 'BUG',
+			 DIST_SOURCE   => 1,
+			);
 
 	# Generate the appropriate rules for this extension.
 	if (((! option 'no-dependencies') && $lang->autodep ne 'no')
@@ -6101,6 +6107,38 @@ sub flatten
   return $_;
 }
 
+# transform($TOKEN, \%PAIRS)
+# ==========================
+# If ($TOKEN, $VAL) is in %PAIRS:
+#   - replaces %$TOKEN% with $VAL,
+#   - enables/disables ?$TOKEN? and ?!$TOKEN?,
+#   - replaces %?$TOKEN% with TRUE or FALSE.
+sub transform($$)
+{
+  my ($token, $transform) = @_;
+
+  if (substr ($token, 0, 1) eq '%')
+    {
+      my $cond = (substr ($token, 1, 1) eq '?') ? 1 : 0;
+      $token = substr ($token, 1 + $cond, -1);
+      my $val = $transform->{$token};
+      prog_error "Unknown %token% `$token'" unless defined $val;
+      if ($cond)
+	{
+	  return $val ? 'TRUE' : 'FALSE';
+	}
+      else
+	{
+	  return $val;
+	}
+    }
+  # Now $token is '?xxx?' or '?!xxx?'.
+  my $neg = (substr ($token, 1, 1) eq '!') ? 1 : 0;
+  $token = substr ($token, 1 + $neg, -1);
+  my $val = $transform->{$token};
+  prog_error "Unknown ?token? `$token' (neg = $neg)" unless defined $val;
+  return (!!$val == $neg) ? '##%' : '';
+}
 
 # @PARAGRAPHS
 # &make_paragraphs ($MAKEFILE, [%TRANSFORM])
@@ -6111,11 +6149,9 @@ sub make_paragraphs ($%)
 {
   my ($file, %transform) = @_;
 
-  # Complete %transform with global options and make it a Perl $command.
+  # Complete %transform with global options.
   # Note that %transform goes last, so it overrides global options.
-  my $command =
-    "s/$IGNORE_PATTERN//gm;"
-    . transform ('CYGNUS'      => !! option 'cygnus',
+  %transform = ('CYGNUS'      => !! option 'cygnus',
 		 'MAINTAINER-MODE'
 		 => $seen_maint_mode ? subst ('MAINTAINER_MODE_TRUE') : '',
 
@@ -6140,9 +6176,7 @@ sub make_paragraphs ($%)
 		 'LIBTOOL'      => !! var ('LIBTOOL'),
 		 'NONLIBTOOL'   => 1,
 		 'FIRST'        => ! $transformed_files{$file},
-		 %transform)
-    # We don't need more than two consecutive new-lines.
-    . 's/\n{3,}/\n\n/g';
+		%transform);
 
   $transformed_files{$file} = 1;
 
@@ -6154,17 +6188,25 @@ sub make_paragraphs ($%)
   undef $/;
   $_ = $fc_file->getline;
   $/ = $saved_dollar_slash;
-  eval $command;
   $fc_file->close;
-  my $content = $_;
+
+  # Remove ##-comments.
+  # Besides we don't need more than two consecutive new-lines.
+  s/(?:$IGNORE_PATTERN|(?<=\n\n)\n+)//gom;
+  # Substitute Automake template tokens.
+  s/(?:%\??[\w\-]+%|\?!?[\w\-]+\?)/transform($&, \%transform)/ge;
+  # transform() may have added some ##%-comments to strip.
+  # (we use `##%' instead of `##' so we can distinguish ##%##%##% from
+  # ####### and do not remove the latter.)
+  s/^[ \t]*(?:##%)+.*\n//gm;
 
   # Split at unescaped new lines.
-  my @lines = split (/(?<!\\)\n/, $content);
+  my @lines = split (/(?<!\\)\n/, $_);
   my @res;
 
   while (defined ($_ = shift @lines))
     {
-      my $paragraph = "$_";
+      my $paragraph = $_;
       # If we are a rule, eat as long as we start with a tab.
       if (/$RULE_PATTERN/smo)
 	{
@@ -6187,7 +6229,6 @@ sub make_paragraphs ($%)
 	}
 
       push @res, $paragraph;
-      $paragraph = '';
     }
 
   return @res;
@@ -6410,38 +6451,6 @@ sub file_contents ($$%)
 }
 
 
-# $REGEXP
-# &transform (%PAIRS)
-# -------------------
-# For each ($TOKEN, $VAL) in %PAIRS produce a replacement expression
-# suitable for file_contents which:
-#   - replaces %$TOKEN% with $VAL,
-#   - enables/disables ?$TOKEN? and ?!$TOKEN?,
-#   - replaces %?$TOKEN% with TRUE or FALSE.
-sub transform (%)
-{
-  my (%pairs) = @_;
-  my $result = '';
-
-  while (my ($token, $val) = each %pairs)
-    {
-      $result .= "s/\Q%$token%\E/\Q$val\E/gm;";
-      if ($val)
-	{
-	  $result .= "s/\Q?$token?\E//gm;s/^.*\Q?!$token?\E.*\\n//gm;";
-	  $result .= "s/\Q%?$token%\E/TRUE/gm;";
-	}
-      else
-	{
-	  $result .= "s/\Q?!$token?\E//gm;s/^.*\Q?$token?\E.*\\n//gm;";
-	  $result .= "s/\Q%?$token%\E/FALSE/gm;";
-	}
-    }
-
-  return $result;
-}
-
-
 # &append_exeext ($MACRO)
 # -----------------------
 # Macro is an Automake magic macro which primary is PROGRAMS, e.g.
-- 
2.47.2