Fix debug info for anon union.

This is tested by anon-union.exp.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116372 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CGDebugInfo.cpp

@@ -144,7 +144,6 @@ CGDebugInfo::getClassName(RecordDecl *RD) {
   char *StrPtr = DebugInfoNames.Allocate<char>(Buffer.length());
   memcpy(StrPtr, Buffer.data(), Buffer.length());
   return llvm::StringRef(StrPtr, Buffer.length());
-
 }
 
 /// getOrCreateFile - Get the file debug info descriptor for the input location.
@@ -1793,20 +1792,54 @@ void CGDebugInfo::EmitDeclare(const VarDecl *VD, unsigned Tag,
   unsigned Flags = 0;
   if (VD->isImplicit())
     Flags |= llvm::DIDescriptor::FlagArtificial;
+  llvm::MDNode *Scope = RegionStack.back();
+    
+  llvm::StringRef Name = VD->getName();
+  if (!Name.empty()) {
     // Create the descriptor for the variable.
     llvm::DIVariable D =
-    DebugFactory.CreateVariable(Tag, llvm::DIDescriptor(RegionStack.back()),
-                                VD->getName(), Unit, Line, Ty, 
+      DebugFactory.CreateVariable(Tag, llvm::DIDescriptor(Scope),
+                                  Name, Unit, Line, Ty, 
                                   CGM.getLangOptions().Optimize, Flags);
     
     // Insert an llvm.dbg.declare into the current block.
     llvm::Instruction *Call =
       DebugFactory.InsertDeclare(Storage, D, Builder.GetInsertBlock());
     
-  llvm::MDNode *Scope = RegionStack.back();
     Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
   }
   
+  // If VD is an anonymous union then Storage represents value for
+  // all union fields.
+  if (const RecordType *RT = dyn_cast<RecordType>(VD->getType()))
+    if (const RecordDecl *RD = dyn_cast<RecordDecl>(RT->getDecl()))
+      if (RD->isUnion()) {
+        for (RecordDecl::field_iterator I = RD->field_begin(),
+               E = RD->field_end();
+             I != E; ++I) {
+          FieldDecl *Field = *I;
+          llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
+          llvm::StringRef FieldName = Field->getName();
+          
+          // Ignore unnamed fields. Do not ignore unnamed records.
+          if (FieldName.empty() && !isa<RecordType>(Field->getType()))
+            continue;
+          
+          // Use VarDecl's Tag, Scope and Line number.
+          llvm::DIVariable D =
+            DebugFactory.CreateVariable(Tag, llvm::DIDescriptor(Scope),
+                                        FieldName, Unit, Line, FieldTy, 
+                                        CGM.getLangOptions().Optimize, Flags);
+          
+          // Insert an llvm.dbg.declare into the current block.
+          llvm::Instruction *Call =
+            DebugFactory.InsertDeclare(Storage, D, Builder.GetInsertBlock());
+          
+          Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
+        }
+      }
+}
+
 /// EmitDeclare - Emit local variable declaration debug info.
 void CGDebugInfo::EmitDeclare(const BlockDeclRefExpr *BDRE, unsigned Tag,
                               llvm::Value *Storage, CGBuilderTy &Builder,

lib/CodeGen/CGDebugInfo.h

@@ -233,6 +233,7 @@ private:
   /// name is constructred on demand (e.g. C++ destructor) then the name
   /// is stored on the side.
   llvm::StringRef getFunctionName(const FunctionDecl *FD);
+
   /// getObjCMethodName - Returns the unmangled name of an Objective-C method.
   /// This is the display name for the debugging info.  
   llvm::StringRef getObjCMethodName(const ObjCMethodDecl *FD);