From 956e5aa3bd32212c6902a585a367dbf58d685340 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@gmail.com>
Date: Fri, 26 Jul 2013 17:02:36 +0000
Subject: [PATCH] Add a way to get the context of any particular scope.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187212 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/DebugInfo.h |  3 +++
 lib/IR/DebugInfo.cpp     | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/llvm/DebugInfo.h b/include/llvm/DebugInfo.h
index ae7bf049444..9fb12f8feb0 100644
--- a/include/llvm/DebugInfo.h
+++ b/include/llvm/DebugInfo.h
@@ -187,6 +187,9 @@ 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.
+    DIScope getContext() const;
     StringRef getFilename() const;
     StringRef getDirectory() const;
   };
diff --git a/lib/IR/DebugInfo.cpp b/lib/IR/DebugInfo.cpp
index 750231658f1..369895ce568 100644
--- a/lib/IR/DebugInfo.cpp
+++ b/lib/IR/DebugInfo.cpp
@@ -692,6 +692,31 @@ Value *DITemplateValueParameter::getValue() const {
   return getField(DbgNode, 4);
 }
 
+// If the current node has a parent scope then return that,
+// else return an empty scope.
+DIScope DIScope::getContext() const {
+
+  if (isType())
+    return DIType(DbgNode).getContext();
+
+  if (isSubprogram())
+    return DISubprogram(DbgNode).getContext();
+
+  if (isLexicalBlock())
+    return DILexicalBlock(DbgNode).getContext();
+
+  if (isLexicalBlockFile())
+    return DILexicalBlockFile(DbgNode).getContext();
+
+  if (isNameSpace())
+    return DINameSpace(DbgNode).getContext();
+
+  if (isFile() || isCompileUnit())
+    return DIScope();
+
+  return DIScope();
+}
+
 StringRef DIScope::getFilename() const {
   if (!DbgNode)
     return StringRef();