[DebugInfo] Generate debug information for labels. (Fix PR37395)

Generate DILabel metadata and call llvm.dbg.label after label
statement to associate the metadata with the label.

After fixing PR37395.
After fixing problems in LiveDebugVariables.

Differential Revision: https://reviews.llvm.org/D45045

llvm-svn: 341519

1 files changed, 26 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index ac22dde9f96..17a24258548 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3769,6 +3769,32 @@ CGDebugInfo::EmitDeclareOfAutoVariable(const VarDecl *VD, llvm::Value *Storage,
   return EmitDeclare(VD, Storage, llvm::None, Builder);
 }
 
+void CGDebugInfo::EmitLabel(const LabelDecl *D, CGBuilderTy &Builder) {
+  assert(DebugKind >= codegenoptions::LimitedDebugInfo);
+  assert(!LexicalBlockStack.empty() && "Region stack mismatch, stack empty!");
+
+  if (D->hasAttr<NoDebugAttr>())
+    return;
+
+  auto *Scope = cast<llvm::DIScope>(LexicalBlockStack.back());
+  llvm::DIFile *Unit = getOrCreateFile(D->getLocation());
+
+  // Get location information.
+  unsigned Line = getLineNumber(D->getLocation());
+  unsigned Column = getColumnNumber(D->getLocation());
+
+  StringRef Name = D->getName();
+
+  // Create the descriptor for the label.
+  auto *L =
+      DBuilder.createLabel(Scope, Name, Unit, Line, CGM.getLangOpts().Optimize);
+
+  // Insert an llvm.dbg.label into the current block.
+  DBuilder.insertLabel(L,
+                       llvm::DebugLoc::get(Line, Column, Scope, CurInlinedAt),
+                       Builder.GetInsertBlock());
+}
+
 llvm::DIType *CGDebugInfo::CreateSelfType(const QualType &QualTy,
                                           llvm::DIType *Ty) {
   llvm::DIType *CachedTy = getTypeOrNull(QualTy);