From: Eli Friedman <eli.friedman@gmail.com>
Date: Sat, 3 Mar 2012 04:09:56 +0000 (+0000)
Subject: Avoid an unnecessary recursive loop between type canonicalization and NNS canonicaliz... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=16412ef25a2203b7066d0db2b41f944631e5cf79;p=clang

Avoid an unnecessary recursive loop between type canonicalization and NNS canonicalization which would (rarely) lead to memory corruption.  While I'm here, simplify.  Fixes PR12166.  Not committing a testcase because it's impossible to reduce it.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151967 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index e0056da60b..9424bc3006 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -3376,26 +3376,13 @@ ASTContext::getCanonicalNestedNameSpecifier(NestedNameSpecifier *NNS) const {
     // types, e.g.,
     //   typedef typename T::type T1;
     //   typedef typename T1::type T2;
-    if (const DependentNameType *DNT = T->getAs<DependentNameType>()) {
-      NestedNameSpecifier *Prefix
-        = getCanonicalNestedNameSpecifier(DNT->getQualifier());
-      return NestedNameSpecifier::Create(*this, Prefix, 
+    if (const DependentNameType *DNT = T->getAs<DependentNameType>())
+      return NestedNameSpecifier::Create(*this, DNT->getQualifier(), 
                            const_cast<IdentifierInfo *>(DNT->getIdentifier()));
-    }    
 
-    // Do the same thing as above, but with dependent-named specializations.
-    if (const DependentTemplateSpecializationType *DTST
-          = T->getAs<DependentTemplateSpecializationType>()) {
-      NestedNameSpecifier *Prefix
-        = getCanonicalNestedNameSpecifier(DTST->getQualifier());
-      
-      T = getDependentTemplateSpecializationType(DTST->getKeyword(),
-                                                 Prefix, DTST->getIdentifier(),
-                                                 DTST->getNumArgs(),
-                                                 DTST->getArgs());
-      T = getCanonicalType(T);
-    }
-    
+    // Otherwise, just canonicalize the type, and force it to be a TypeSpec.
+    // FIXME: Why are TypeSpec and TypeSpecWithTemplate distinct in the
+    // first place?
     return NestedNameSpecifier::Create(*this, 0, false,
                                        const_cast<Type*>(T.getTypePtr()));
   }