Change 33337: Setting the f flag on length causes the op to be constant folded.

Change 33337 by nicholas@nicholas-bouvard on 2008/02/20 09:21:53

	Setting the f flag on length causes the op to be constant folded.

Affected files ...

... //depot/perl/opcode.h#149 edit
... //depot/perl/opcode.pl#172 edit
... //depot/perl/t/lib/warnings/7fatal#6 edit

Differences ...

==== //depot/perl/opcode.h#149 (text+w) ====
Index: perl/opcode.h
--- perl/opcode.h#148~33267~	2008-02-09 23:35:45.000000000 -0800
+++ perl/opcode.h	2008-02-20 01:21:53.000000000 -0800
@@ -1658,7 +1658,7 @@
 	0x0001378e,	/* hex */
 	0x0001378e,	/* oct */
 	0x0001378e,	/* abs */
-	0x0001379c,	/* length */
+	0x0001379e,	/* length */
 	0x1322280c,	/* substr */
 	0x0022281c,	/* vec */
 	0x0122291c,	/* index */

==== //depot/perl/opcode.pl#172 (xtext) ====
Index: perl/opcode.pl
--- perl/opcode.pl#171~33267~	2008-02-09 23:35:45.000000000 -0800
+++ perl/opcode.pl	2008-02-20 01:21:53.000000000 -0800
@@ -760,7 +760,7 @@
 
 # String stuff.
 
-length		length			ck_lengthconst	isTu%	S?
+length		length			ck_lengthconst	ifsTu%	S?
 substr		substr			ck_substr	st@	S S S? S?
 vec		vec			ck_fun		ist@	S S S
 

==== //depot/perl/t/lib/warnings/7fatal#6 (text) ====
Index: perl/t/lib/warnings/7fatal
--- perl/t/lib/warnings/7fatal#5~30124~	2007-02-04 16:13:08.000000000 -0800
+++ perl/t/lib/warnings/7fatal	2008-02-20 01:21:53.000000000 -0800
@@ -285,7 +285,8 @@
 
 {
     use warnings FATAL => qw(void) ;
-    length "abc" ;
+    $a = "abc";
+    length $a ;
 }
 
 join "", 1,2,3 ;
@@ -293,7 +294,7 @@
 print "done\n" ;
 EXPECT
 Useless use of time in void context at - line 4.
-Useless use of length in void context at - line 8.
+Useless use of length in void context at - line 9.
 ########
 # TODO ? !$Config{usethreads} && $::UTF8 && ($ENV{PERL_DESTRUCT_LEVEL} || 0) > 1 ? "Parser leaks OPs, which leak shared hash keys" : ''
 
@@ -303,7 +304,8 @@
 
 {
     use warnings FATAL => qw(void) ;
-    length "abc" ;
+    $a = "abc";
+    length $a ;
 }
 
 join "", 1,2,3 ;
@@ -311,7 +313,7 @@
 print "done\n" ;
 EXPECT
 Useless use of time in void context at - line 4.
-Useless use of length in void context at - line 8.
+Useless use of length in void context at - line 9.
 ########
 
 use warnings FATAL => 'all';
@@ -362,35 +364,39 @@
 
 use warnings FATAL => 'syntax', NONFATAL => 'void' ;
 
-length "abc";
+$a = "abc";
+length $a;
 print STDERR "The End.\n" ;
 EXPECT
-Useless use of length in void context at - line 4.
+Useless use of length in void context at - line 5.
 The End.
 ########
 
 use warnings FATAL => 'all', NONFATAL => 'void' ;
 
-length "abc";
+$a = "abc";
+length $a;
 print STDERR "The End.\n" ;
 EXPECT
-Useless use of length in void context at - line 4.
+Useless use of length in void context at - line 5.
 The End.
 ########
 
 use warnings FATAL => 'all', NONFATAL => 'void' ;
 
 my $a ; chomp $a;
-length "abc";
+
+$b = "abc" ;
+length $b;
 print STDERR "The End.\n" ;
 EXPECT
-Useless use of length in void context at - line 5.
+Useless use of length in void context at - line 7.
 Use of uninitialized value $a in scalar chomp at - line 4.
 ########
 
 use warnings FATAL => 'void', NONFATAL => 'void' ;
-
-length "abc";
+$a = "abc";
+length $a;
 print STDERR "The End.\n" ;
 EXPECT
 Useless use of length in void context at - line 4.
@@ -399,8 +405,8 @@
 # TODO ? !$Config{usethreads} && $::UTF8 && ($ENV{PERL_DESTRUCT_LEVEL} || 0) > 1 ? "Parser leaks OPs, which leak shared hash keys" : ''
 
 use warnings NONFATAL => 'void', FATAL => 'void' ;
-
-length "abc";
+$a = "abc";
+length $a;
 print STDERR "The End.\n" ;
 EXPECT
 Useless use of length in void context at - line 4.
End of Patch.

• Change 33337: Setting the f flag on length causes the op to be constant folded. by Nicholas Clark