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

1 files changed, 2 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Utils/AddDiscriminators.cpp b/llvm/lib/Transforms/Utils/AddDiscriminators.cpp
index 196ac79aaf2..f8e5af5c768 100644
--- a/llvm/lib/Transforms/Utils/AddDiscriminators.cpp
+++ b/llvm/lib/Transforms/Utils/AddDiscriminators.cpp
@@ -193,13 +193,11 @@ bool AddDiscriminators::runOnFunction(Function &F) {
         // Create a new lexical scope and compute a new discriminator
         // number for it.
         StringRef Filename = FirstDIL.getFilename();
-        unsigned LineNumber = FirstDIL.getLineNumber();
-        unsigned ColumnNumber = FirstDIL.getColumnNumber();
         DIScope Scope = FirstDIL.getScope();
         DIFile File = Builder.createFile(Filename, Scope.getDirectory());
         unsigned Discriminator = FirstDIL.computeNewDiscriminator(Ctx);
-        DILexicalBlock NewScope = Builder.createLexicalBlock(
-            Scope, File, LineNumber, ColumnNumber, Discriminator);
+        DILexicalBlockFile NewScope =
+            Builder.createLexicalBlockFile(Scope, File, Discriminator);
         DILocation NewDIL = FirstDIL.copyWithNewScope(Ctx, NewScope);
         DebugLoc newDebugLoc = DebugLoc::getFromDILocation(NewDIL);