From b31cfda0f8a53fa9ddf15ec454fb65c69e977dc7 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Mon, 31 Aug 2009 20:44:45 +0000
Subject: [PATCH] Introduce DIScope.

llvm-svn: 80620
---
 include/llvm/Analysis/DebugInfo.h | 10 ++++++++++
 lib/Analysis/DebugInfo.cpp        | 16 ++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/llvm/Analysis/DebugInfo.h b/include/llvm/Analysis/DebugInfo.h
index 01c1decb83d..b8a6ce3cd54 100644
--- a/include/llvm/Analysis/DebugInfo.h
+++ b/include/llvm/Analysis/DebugInfo.h
@@ -94,6 +94,7 @@ namespace llvm {
     bool isVariable() const;
     bool isSubprogram() const;
     bool isGlobalVariable() const;
+    bool isScope() const;
   };
 
   /// DISubrange - This is used to represent ranges, for array bounds.
@@ -118,6 +119,15 @@ namespace llvm {
     }
   };
 
+  /// DIScope - A base class for various scopes.
+  class DIScope : public DIDescriptor {
+  public:
+    explicit DIScope(MDNode *N = 0) : DIDescriptor (N) {
+      if (DbgNode && !isScope())
+        DbgNode = 0;
+    }
+  };
+
   /// DICompileUnit - A wrapper for a compile unit.
   class DICompileUnit : public DIDescriptor {
   public:
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index a67539c1a07..e815931e611 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -210,6 +210,22 @@ bool DIDescriptor::isGlobalVariable() const {
   return Tag == dwarf::DW_TAG_variable;
 }
 
+/// isScope - Return true if the specified tag is one of the scope 
+/// related tag.
+bool DIDescriptor::isScope() const {
+  assert (!isNull() && "Invalid descriptor!");
+  unsigned Tag = getTag();
+
+  switch (Tag) {
+    case dwarf::DW_TAG_compile_unit:
+    case dwarf::DW_TAG_lexical_block:
+    case dwarf::DW_TAG_subprogram:
+      return true;
+    default:
+      break;
+  }
+  return false;
+}
 
 //===----------------------------------------------------------------------===//
 // Simple Descriptor Constructors and other Methods