1 files changed, 23 insertions, 1 deletions
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index c87d74657d7..bcd5338ac05 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3168,6 +3168,7 @@ llvm::DISubprogram *CGDebugInfo::getFunctionFwdDeclOrStub(GlobalDecl GD,
   QualType FnType = CGM.getContext().getFunctionType(
       FD->getReturnType(), ArgTypes, FunctionProtoType::ExtProtoInfo(CC));
   if (Stub) {
+    Flags |= getCallSiteRelatedAttrs();
     return DBuilder.createFunction(
         DContext, Name, LinkageName, Unit, Line,
         getOrCreateFunctionType(GD.getDecl(), FnType, Unit),
@@ -3407,6 +3408,8 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, SourceLocation Loc,
   if (CurFuncIsThunk)
     Flags |= llvm::DINode::FlagThunk;
 
+  llvm::DINode::DIFlags FlagsForDef = Flags | getCallSiteRelatedAttrs();
+
   unsigned LineNo = getLineNumber(Loc);
   unsigned ScopeLine = getLineNumber(ScopeLoc);
 
@@ -3418,7 +3421,7 @@ void CGDebugInfo::EmitFunctionStart(GlobalDecl GD, SourceLocation Loc,
   llvm::DISubprogram *SP = DBuilder.createFunction(
       FDContext, Name, LinkageName, Unit, LineNo,
       getOrCreateFunctionType(D, FnType, Unit), Fn->hasLocalLinkage(),
-      true /*definition*/, ScopeLine, Flags, CGM.getLangOpts().Optimize,
+      true /*definition*/, ScopeLine, FlagsForDef, CGM.getLangOpts().Optimize,
       TParamsArray.get(), getFunctionDeclaration(D));
   Fn->setSubprogram(SP);
   // We might get here with a VarDecl in the case we're generating
@@ -4422,3 +4425,22 @@ llvm::DebugLoc CGDebugInfo::SourceLocToDebugLoc(SourceLocation Loc) {
   llvm::MDNode *Scope = LexicalBlockStack.back();
   return llvm::DebugLoc::get(getLineNumber(Loc), getColumnNumber(Loc), Scope);
 }
+
+llvm::DINode::DIFlags CGDebugInfo::getCallSiteRelatedAttrs() const {
+  // Call site-related attributes are only useful in optimized programs, and
+  // when there's a possibility of debugging backtraces.
+  if (!CGM.getLangOpts().Optimize || DebugKind == codegenoptions::NoDebugInfo ||
+      DebugKind == codegenoptions::LocTrackingOnly)
+    return llvm::DINode::FlagZero;
+
+  // Call site-related attributes are available in DWARF v5. Some debuggers,
+  // while not fully DWARF v5-compliant, may accept these attributes as if they
+  // were part of DWARF v4.
+  bool SupportsDWARFv4Ext =
+      CGM.getCodeGenOpts().DwarfVersion == 4 &&
+      CGM.getCodeGenOpts().getDebuggerTuning() == llvm::DebuggerKind::LLDB;
+  if (!SupportsDWARFv4Ext && CGM.getCodeGenOpts().DwarfVersion < 5)
+    return llvm::DINode::FlagZero;
+
+  return llvm::DINode::FlagAllCallsDescribed;
+}