DebugInfo: Don't create duplicate forward declaration metadata unnecessarily.

No functionality change, at best a slight (questionable) optimization,
but necessary for correctness of future work.

llvm-svn: 188474

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 1d3bad9f6dd128d2d092c808313121e848fabdce..8eb89871c559eb1c28821ed2e6c77e5019892c8f 100644 (file)
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -602,8 +602,12 @@ llvm::DIType CGDebugInfo::CreateType(const PointerType *Ty,
 }
 
 // Creates a forward declaration for a RecordDecl in the given context.
-llvm::DIType CGDebugInfo::createRecordFwdDecl(const RecordDecl *RD,
-                                              llvm::DIDescriptor Ctx) {
+llvm::DICompositeType
+CGDebugInfo::getOrCreateRecordFwdDecl(const RecordDecl *RD,
+                                      llvm::DIDescriptor Ctx) {
+  llvm::DICompositeType T(getTypeOrNull(CGM.getContext().getRecordType(RD)));
+  if (T)
+    return T;
   llvm::DIFile DefUnit = getOrCreateFile(RD->getLocation());
   unsigned Line = getLineNumber(RD->getLocation());
   StringRef RDName = getClassName(RD);
@@ -1413,7 +1417,7 @@ llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty, bool Declaration) {
     // test/CodeGen/debug-info-records.c .
     llvm::DIDescriptor FDContext =
       getContextDescriptor(cast<Decl>(RD->getDeclContext()));
-    llvm::DIType RetTy = createRecordFwdDecl(RD, FDContext);
+    llvm::DIType RetTy = getOrCreateRecordFwdDecl(RD, FDContext);
     TypeCache[QualType(Ty, 0).getAsOpaquePtr()] = RetTy;
     return RetTy;
   }
@@ -2175,7 +2179,7 @@ llvm::DIType CGDebugInfo::CreateLimitedType(const RecordType *Ty) {
   // If this is just a forward declaration, construct an appropriately
   // marked node and just return it.
   if (!RD->getDefinition())
-    return createRecordFwdDecl(RD, RDContext);
+    return getOrCreateRecordFwdDecl(RD, RDContext);
 
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
   uint64_t Align = CGM.getContext().getTypeAlign(Ty);

diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 68cc690216b653d835745671732b5a57d9fe3dbf..3a0d07f2a8c4ce88c02136b2930d6e12f0878070 100644 (file)
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -305,9 +305,9 @@ private:
 
   llvm::DIScope getCurrentContextDescriptor(const Decl *Decl);
 
-  /// createRecordFwdDecl - Create a forward decl for a RecordType in a given
-  /// context.
-  llvm::DIType createRecordFwdDecl(const RecordDecl *, llvm::DIDescriptor);
+  /// \brief Create a forward decl for a RecordType in a given context.
+  llvm::DICompositeType getOrCreateRecordFwdDecl(const RecordDecl *,
+                                                 llvm::DIDescriptor);
 
   /// createContextChain - Create a set of decls for the context chain.
   llvm::DIDescriptor createContextChain(const Decl *Decl);