[m-dev.] diff: fix infinite loop in mtags

[Fergus Henderson]

Estimated hours taken: 0.5

scripts/mtags:
	Fix a bug: take care to avoid infinite loops when processing
	typeclass and instance declarations.

Workspace: /d-drive/home/hg/fjh/mercury
Index: scripts/mtags
===================================================================
RCS file: /home/mercury1/repository/mercury/scripts/mtags,v
retrieving revision 1.18
diff -u -r1.18 mtags
--- scripts/mtags	1998/08/10 06:54:59	1.18
+++ scripts/mtags	1999/10/07 11:49:55
@@ -294,12 +294,10 @@
 
 	# skip declarations which are not definitions
 	next unless (
-	    # pred, func, typeclass and instance declarations are always
-	    # definitions
+	    # pred, func, and typeclass declarations are always definitions
 	    $decl eq "pred" ||
 	    $decl eq "func" ||
 	    $decl eq "typeclass" ||
-	    $decl eq "instance"  ||
 
 	    # if it doesn't end in a `.' (i.e if it doesn't fit on one line),
 	    # then it's probably a definition
@@ -347,7 +345,7 @@
 		    $body =~ s/[^;]*;[ \t]*//;
 
 		    if ($body =~ /^[ \t]*$/) {
-			$_ = <srcfile>;
+			$_ = <srcfile> || last;
 			chop;
 			$body = $_;
 		    }
@@ -366,7 +364,7 @@
 		}
 		    
 		last if $_ =~ /\.[ \t]*$/ || $_ =~ /\.[ \t]*%.*$/;
-		$_ = <srcfile>;
+		$_ = <srcfile> || last;
 		chop;
 		$body = $_;
 	    }
@@ -379,7 +377,7 @@
 		    $body =~ s/^.*\b(pred|func)[ \t]*//;
 
 		    if ($body =~ /^[ \t]*$/) {
-		    	$_ = <srcfile>;
+		    	$_ = <srcfile> || last;
 		    	chop;
 		    	$body = $_;
 		    }
@@ -390,9 +388,9 @@
 		    do output_name();
 		}
 
-		last if $_ =~ /\]/;
+		last if $_ =~ /\.[ \t]*$/ || $_ =~ /\]/;
 
-		$_ = <srcfile>;
+		$_ = <srcfile> || last;
 		chop;
 		$body = $_;
 	    }
@@ -404,7 +402,7 @@
 		    $body =~ s/.*\b(pred\(|func\()//;
 
 		    if ($body =~ /^[ \t]*$/) {
-		    	$_ = <srcfile>;
+		    	$_ = <srcfile> || last;
 		    	chop;
 		    	$body = $_;
 		    }
@@ -415,9 +413,9 @@
 		    do output_name();
 		}
 
-		last if $_ =~ /\]/;
+		last if $_ =~ /\.[ \t]*$/ || $_ =~ /\]/;
 
-		$_ = <srcfile>;
+		$_ = <srcfile> || last;
 		chop;
 		$body = $_;
 	    }

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>  |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3        |     -- the last words of T. S. Garp.
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