From f499b34d4911dda3b20ede1377ea29b83d3f149e Mon Sep 17 00:00:00 2001
From: Richard Trieu <rtrieu@google.com>
Date: Thu, 31 Jan 2013 02:47:46 +0000
Subject: [PATCH] When comparing two template template arguments in the
 template differ, consider them the same if they are actually the same; having
 the same name isn't enough.

Similar to r174013, template template arguments were also mistakenly considered
the same when they had the same name but were in different namespaces.
In addition, when printing template template arguments, use the qualified name
if the regular name is the same.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174029 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/AST/ASTDiagnostic.cpp           | 19 ++++++++++++++-----
 test/Misc/diag-template-diffing.cpp |  8 ++++++++
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/lib/AST/ASTDiagnostic.cpp b/lib/AST/ASTDiagnostic.cpp
index fb3544f03a..4f165132a6 100644
--- a/lib/AST/ASTDiagnostic.cpp
+++ b/lib/AST/ASTDiagnostic.cpp
@@ -894,8 +894,9 @@ class TemplateDiff {
         GetTemplateDecl(FromIter, DefaultTTPD, FromDecl);
         GetTemplateDecl(ToIter, DefaultTTPD, ToDecl);
         Tree.SetNode(FromDecl, ToDecl);
-        Tree.SetSame(FromDecl && ToDecl &&
-                     FromDecl->getIdentifier() == ToDecl->getIdentifier());
+        Tree.SetSame(
+            FromDecl && ToDecl &&
+            FromDecl->getCanonicalDecl() == ToDecl->getCanonicalDecl());
       }
 
       if (!FromIter.isEnd()) ++FromIter;
@@ -1278,21 +1279,29 @@ class TemplateDiff {
   void PrintTemplateTemplate(TemplateDecl *FromTD, TemplateDecl *ToTD,
                              bool FromDefault, bool ToDefault, bool Same) {
     assert((FromTD || ToTD) && "Only one template argument may be missing.");
+
+    std::string FromName = FromTD ? FromTD->getName() : "(no argument)";
+    std::string ToName = ToTD ? ToTD->getName() : "(no argument)";
+    if (FromTD && ToTD && FromName == ToName) {
+      FromName = FromTD->getQualifiedNameAsString();
+      ToName = ToTD->getQualifiedNameAsString();
+    }
+
     if (Same) {
       OS << "template " << FromTD->getNameAsString();
     } else if (!PrintTree) {
       OS << (FromDefault ? "(default) template " : "template ");
       Bold();
-      OS << (FromTD ? FromTD->getNameAsString() : "(no argument)");
+      OS << FromName;
       Unbold();
     } else {
       OS << (FromDefault ? "[(default) template " : "[template ");
       Bold();
-      OS << (FromTD ? FromTD->getNameAsString() : "(no argument)");
+      OS << FromName;
       Unbold();
       OS << " != " << (ToDefault ? "(default) template " : "template ");
       Bold();
-      OS << (ToTD ? ToTD->getNameAsString() : "(no argument)");
+      OS << ToName;
       Unbold();
       OS << ']';
     }
diff --git a/test/Misc/diag-template-diffing.cpp b/test/Misc/diag-template-diffing.cpp
index 7e9998c828..c6fc32d1b3 100644
--- a/test/Misc/diag-template-diffing.cpp
+++ b/test/Misc/diag-template-diffing.cpp
@@ -859,6 +859,14 @@ namespace rdar12931988 {
     // CHECK-ELIDE-NOTREE: no known conversion from 'B::X<int>' to 'const rdar12931988::A::X<int>'
     ax = bx;
   }
+
+  template<template<typename> class> class Y {};
+
+  void bar(Y<A::X> ya, Y<B::X> yb) {
+    // CHECK-ELIDE-NOTREE: no viable overloaded '='
+    // CHECK-ELIDE-NOTREE: no known conversion from 'Y<template rdar12931988::B::X>' to 'Y<template rdar12931988::A::X>'
+    ya = yb;
+  }
 }
 
 // CHECK-ELIDE-NOTREE: {{[0-9]*}} errors generated.
-- 
2.40.0