From 5e4e50c2808aa9fca667f8ba50eb4b459b51c935 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Sun, 10 May 2009 22:59:12 +0000
Subject: [PATCH] The canonical declaration of a NULL declaration is NULL

llvm-svn: 71409
---
 clang/lib/AST/ASTContext.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index f9d648b816b3..52eadef75ab9 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1704,6 +1704,9 @@ QualType ASTContext::getCanonicalType(QualType T) {
 }
 
 Decl *ASTContext::getCanonicalDecl(Decl *D) {
+  if (!D)
+    return 0;
+
   if (TagDecl *Tag = dyn_cast<TagDecl>(D)) {
     QualType T = getTagDeclType(Tag);
     return cast<TagDecl>(cast<TagType>(T.getTypePtr()->CanonicalType)