3 Commits

Author	SHA1	Message	Date
David Blaikie	8da0c326fb	Use DILexicalBlockFile, rather than DILexicalBlock, to track discriminator changes to ensure discriminator changes don't introduce new DWARF DW_TAG_lexical_blocks. ... Somewhat unnoticed in the original implementation of discriminators, but it could cause instructions to end up in new, small, DW_TAG_lexical_blocks due to the use of DILexicalBlock to track discriminator changes. Instead, use DILexicalBlockFile which we already use to track file changes without introducing new scopes, so it works well to track discriminator changes in the same way. llvm-svn: 216239	2014-08-21 22:45:21 +00:00
Diego Novillo	45811c5ea3	Fix bug 19437 - Only add discriminators for DWARF 4 and above. ... Summary: This prevents the discriminator generation pass from triggering if the DWARF version being used in the module is prior to 4. Reviewers: echristo, dblaikie CC: llvm-commits Differential Revision: http://reviews.llvm.org/D3413 llvm-svn: 206507	2014-04-17 22:33:50 +00:00
Diego Novillo	2ccb22f509	Pass to emit DWARF path discriminators. ... DWARF discriminators are used to distinguish multiple control flow paths on the same source location. When this happens, instructions across basic block boundaries will share the same debug location. This pass detects this situation and creates a new lexical scope to one of the two instructions. This lexical scope is a child scope of the original and contains a new discriminator value. This discriminator is then picked up from MCObjectStreamer::EmitDwarfLocDirective to be written on the object file. This fixes http://llvm.org/bugs/show_bug.cgi?id=18270. llvm-svn: 202752	2014-03-03 20:06:11 +00:00