Debug Info: move DIScope::getContext back from DwarfDebug.

This partially reverts r190330. DIScope::getContext now returns DIScopeRef
instead of DIScope. We construct a DIScopeRef from DIScope when we are
dealing with subprogram, lexical block or name space.

llvm-svn: 190362

llvm/include/llvm/DebugInfo.h

@@ -200,6 +200,9 @@ namespace llvm {
   public:
     explicit DIScope(const MDNode *N = 0) : DIDescriptor (N) {}
 
+    /// Gets the parent scope for this scope node or returns a
+    /// default constructed scope.
+    DIScopeRef getContext() const;
     StringRef getFilename() const;
     StringRef getDirectory() const;
 
@@ -213,6 +216,7 @@ namespace llvm {
   class DIScopeRef {
     template <typename DescTy>
     friend DescTy DIDescriptor::getFieldAs(unsigned Elt) const;
+    friend DIScopeRef DIScope::getContext() const;
 
     /// Val can be either a MDNode or a MDString, in the latter,
     /// MDString specifies the type identifier.

llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

@@ -919,7 +919,7 @@ static bool isTypeUnitScoped(DIType Ty, const DwarfDebug *DD) {
     // Don't generate a hash for anything scoped inside a function.
     if (Parent.isSubprogram())
       return false;
-    Parent = DD->getScopeContext(Parent);
+    Parent = DD->resolve(Parent.getContext());
   }
   return true;
 }

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -2649,26 +2649,3 @@ void DwarfDebug::emitDebugStrDWO() {
 DIScope DwarfDebug::resolve(DIScopeRef SRef) const {
   return SRef.resolve(TypeIdentifierMap);
 }
-
-// If the current node has a parent scope then return that,
-// else return an empty scope.
-DIScope DwarfDebug::getScopeContext(DIScope S) const {
-
-  if (S.isType())
-    return resolve(DIType(S).getContext());
-
-  if (S.isSubprogram())
-    return DISubprogram(S).getContext();
-
-  if (S.isLexicalBlock())
-    return DILexicalBlock(S).getContext();
-
-  if (S.isLexicalBlockFile())
-    return DILexicalBlockFile(S).getContext();
-
-  if (S.isNameSpace())
-    return DINameSpace(S).getContext();
-
-  assert((S.isFile() || S.isCompileUnit()) && "Unhandled type of scope.");
-  return DIScope();
-}

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -690,9 +690,6 @@ public:
   /// or another context nested inside a subprogram.
   bool isSubprogramContext(const MDNode *Context);
 
-  /// Gets the parent scope for this scope node or returns a
-  /// default constructed scope.
-  DIScope getScopeContext(DIScope S) const;
 };
 } // End of namespace llvm
 

llvm/lib/IR/DebugInfo.cpp

@@ -785,6 +785,29 @@ Value *DITemplateValueParameter::getValue() const {
   return getField(DbgNode, 4);
 }
 
+// If the current node has a parent scope then return that,
+// else return an empty scope.
+DIScopeRef DIScope::getContext() const {
+
+  if (isType())
+    return DIType(DbgNode).getContext();
+
+  if (isSubprogram())
+    return DIScopeRef(DISubprogram(DbgNode).getContext());
+
+  if (isLexicalBlock())
+    return DIScopeRef(DILexicalBlock(DbgNode).getContext());
+
+  if (isLexicalBlockFile())
+    return DIScopeRef(DILexicalBlockFile(DbgNode).getContext());
+
+  if (isNameSpace())
+    return DIScopeRef(DINameSpace(DbgNode).getContext());
+
+  assert((isFile() || isCompileUnit()) && "Unhandled type of scope.");
+  return DIScopeRef(NULL);
+}
+
 StringRef DIScope::getFilename() const {
   if (!DbgNode)
     return StringRef();