137609 2014-10-10 05:27:15 -0700 webkitdirs::isCrossCompilation() cause Perl uninitialized warnings when using native GCC toolchain 2016-04-25 21:00:42 -0700 1 1 1 Unclassified WebKit New Bugs 528+ (Nightly build) Unspecified Unspecified NEW P2 Normal --- 1 pulkomandy webkit-unassigned commit-queue dbates oldest_to_newest 1040899 0 pulkomandy 2014-10-10 05:27:15 -0700 webkitdirs.pm fails when CC is set to native compiler 1040900 1 239621 pulkomandy 2014-10-10 05:32:51 -0700 Created attachment 239621 Patch 1187230 2 239621 dbates 2016-04-25 21:00:42 -0700 Comment on attachment 239621 Patch View in context: https://bugs.webkit.org/attachment.cgi?id=239621&action=review > Tools/ChangeLog:12 > + The perl regexp returns an empty array when there is no match (when > + the compiler in CC is not configured with --target or --host). Trying > + to test the first element of the array will trigger a warning > + "Use of uninitialized value $host[0] in string ne". Test that the > + array is not empty first. Maybe a better way to describe the issue is to say: Fixes an issue where webkitdirs::isCrossCompilation() causes Perl uninitialized warnings when the GCC compiler specified by the environment variable CC was not built for cross compilation. > Tools/Scripts/webkitdirs.pm:1079 > my @host = $compiler_options =~ m/--host=(.*?)\s/; > my @target = $compiler_options =~ m/--target=(.*?)\s/; > > - return ($host[0] ne "" && $target[0] ne "" && $host[0] ne $target[0]); > + return (@host && @target && $host[0] ne "" && $target[0] ne "" && $host[0] ne $target[0]); We are underutilizing the use of an array for holding the captured output of the regular expressions because the regular expression on lines 1076 and 1077 each have exactly one capture group. Using the fact that a captured group is always a string and the property that the empty string evaluates to false in a boolean context, I would write this code as: my $host = $1 if $compiler_options =~ /--host=(.*?)\s/; my $target = $1 if $compiler_options =~ /--target=(.*?)\s/; return ($host && $target && $host ne $target); 239621 2014-10-10 05:32:51 -0700 2016-04-25 21:00:42 -0700 Patch bug-137609-20141010143355.patch text/plain 1622 pulkomandy U3VidmVyc2lvbiBSZXZpc2lvbjogMTc0NTgyCmRpZmYgLS1naXQgYS9Ub29scy9DaGFuZ2VMb2cg Yi9Ub29scy9DaGFuZ2VMb2cKaW5kZXggN2NlZDkwZDFlMzNkZDQ1MjkyMTQ2YmM5YmVlYWRlODk1 MDYxMTk4Ny4uYTRhZWVhYjQ5Y2U2ZTYwODg0Mzc2NTE5M2NlZTEzNzFlZDM0M2QwZiAxMDA2NDQK LS0tIGEvVG9vbHMvQ2hhbmdlTG9nCisrKyBiL1Rvb2xzL0NoYW5nZUxvZwpAQCAtMSw1ICsxLDIx IEBACiAyMDE0LTEwLTEwICBBZHJpZW4gRGVzdHVndWVzICA8cHVsa29tYW5keUBnbWFpbC5jb20+ CiAKKyAgICAgICAgd2Via2l0ZGlycy5wbSB3YXJuaW5nIHdoZW4gQ0MgaXMgc2V0IHRvIG5hdGl2 ZSBjb21waWxlcgorICAgICAgICBodHRwczovL2J1Z3Mud2Via2l0Lm9yZy9zaG93X2J1Zy5jZ2k/ aWQ9MTM3NjA5CisKKyAgICAgICAgUmV2aWV3ZWQgYnkgTk9CT0RZIChPT1BTISkuCisKKyAgICAg ICAgVGhlIHBlcmwgcmVnZXhwIHJldHVybnMgYW4gZW1wdHkgYXJyYXkgd2hlbiB0aGVyZSBpcyBu byBtYXRjaCAod2hlbgorICAgICAgICB0aGUgY29tcGlsZXIgaW4gQ0MgaXMgbm90IGNvbmZpZ3Vy ZWQgd2l0aCAtLXRhcmdldCBvciAtLWhvc3QpLiBUcnlpbmcKKyAgICAgICAgdG8gdGVzdCB0aGUg Zmlyc3QgZWxlbWVudCBvZiB0aGUgYXJyYXkgd2lsbCB0cmlnZ2VyIGEgd2FybmluZworICAgICAg ICAiVXNlIG9mIHVuaW5pdGlhbGl6ZWQgdmFsdWUgJGhvc3RbMF0gaW4gc3RyaW5nIG5lIi4gVGVz dCB0aGF0IHRoZQorICAgICAgICBhcnJheSBpcyBub3QgZW1wdHkgZmlyc3QuCisKKyAgICAgICAg KiBTY3JpcHRzL3dlYmtpdGRpcnMucG06CisgICAgICAgIChpc0Nyb3NzQ29tcGlsYXRpb24pOgor CisyMDE0LTEwLTEwICBBZHJpZW4gRGVzdHVndWVzICA8cHVsa29tYW5keUBnbWFpbC5jb20+CisK ICAgICAgICAgRml4IHBlcmwgc2NyaXB0cyB0byBydW4gd2l0aCBlbnYgb24gTGludXgKICAgICAg ICAgaHR0cHM6Ly9idWdzLndlYmtpdC5vcmcvc2hvd19idWcuY2dpP2lkPTEzNzYwMQogCmRpZmYg LS1naXQgYS9Ub29scy9TY3JpcHRzL3dlYmtpdGRpcnMucG0gYi9Ub29scy9TY3JpcHRzL3dlYmtp dGRpcnMucG0KaW5kZXggNzcyZGNjNDIxNGVhYTJlNmQ3ZmExYjkxODdkMDI0YmQ4MDVjMTJmNS4u ZDIxMTMxMmYwNjkzYjQ1ZmI2ODYzY2YwNjhkMGJmYTU1ODE1ZTMxOCAxMDA3NTUKLS0tIGEvVG9v bHMvU2NyaXB0cy93ZWJraXRkaXJzLnBtCisrKyBiL1Rvb2xzL1NjcmlwdHMvd2Via2l0ZGlycy5w bQpAQCAtMTA3Niw3ICsxMDc2LDcgQEAgc3ViIGlzQ3Jvc3NDb21waWxhdGlvbigpCiAgICAgICBt eSBAaG9zdCA9ICRjb21waWxlcl9vcHRpb25zID1+IG0vLS1ob3N0PSguKj8pXHMvOwogICAgICAg bXkgQHRhcmdldCA9ICRjb21waWxlcl9vcHRpb25zID1+IG0vLS10YXJnZXQ9KC4qPylccy87CiAK LSAgICAgIHJldHVybiAoJGhvc3RbMF0gbmUgIiIgJiYgJHRhcmdldFswXSBuZSAiIiAmJiAkaG9z dFswXSBuZSAkdGFyZ2V0WzBdKTsKKyAgICAgIHJldHVybiAoQGhvc3QgJiYgQHRhcmdldCAmJiAk aG9zdFswXSBuZSAiIiAmJiAkdGFyZ2V0WzBdIG5lICIiICYmICRob3N0WzBdIG5lICR0YXJnZXRb MF0pOwogICB9CiAgIHJldHVybiAwOwogfQo=