DebugInfo: Include the decl_line/decl_file in subprogram definitions if they differ from those in the declaration

This is handy for some AutoFDO stuff, and seems like a minor improvement
to correctness (otherwise a debug info consumer might think the decl
line/file of the def was the same as that of the declaration - though
what a consumer might use that for, I'm not sure - maybe "list <func>"
would've misbehaved with the old behavior?) and at a minor cost (in my
experiment, with fission, without type units, without compression, 0.01%
growth in debug info in the executable/objects, 0.02% growth in the .dwo
files).

llvm-svn: 249487

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 3a89c809da3..c441a67a5d7 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1151,6 +1151,14 @@ bool DwarfUnit::applySubprogramDefinitionAttributes(const DISubprogram *SP,
                       "definition DIE was created in "
                       "getOrCreateSubprogramDIE");
     DeclLinkageName = SPDecl->getLinkageName();
+    unsigned DeclID =
+        getOrCreateSourceID(SPDecl->getFilename(), SPDecl->getDirectory());
+    unsigned DefID = getOrCreateSourceID(SP->getFilename(), SP->getDirectory());
+    if (DeclID != DefID)
+      addUInt(SPDie, dwarf::DW_AT_decl_file, None, DefID);
+
+    if (SP->getLine() != SPDecl->getLine())
+      addUInt(SPDie, dwarf::DW_AT_decl_line, None, SP->getLine());
   }
 
   // Add function template parameters.