r212788 - [modules] Don't try to merge template specializations by performing name lookup

[Richard Smith]

Author: rsmith
Date: Thu Jul 10 19:20:06 2014
New Revision: 212788

URL: http://llvm.org/viewvc/llvm-project?rev=212788&view=rev
Log:
[modules] Don't try to merge template specializations by performing name lookup
into their container; we won't find them there. These things are already being
merged when they're added to their primary template's folding set, so this
merging is redundant (and causes us to reject-valid because we think we've
found an odr violation).

Modified:
    cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
    cfe/trunk/test/Modules/Inputs/cxx-templates-a.h
    cfe/trunk/test/Modules/Inputs/cxx-templates-b.h
    cfe/trunk/test/Modules/Inputs/cxx-templates-common.h
    cfe/trunk/test/Modules/cxx-templates.cpp

Modified: cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=212788&r1=212787&r2=212788&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTReaderDecl.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTReaderDecl.cpp Thu Jul 10 19:20:06 2014
@@ -1017,7 +1017,8 @@ ASTDeclReader::RedeclarableResult ASTDec
   switch ((VarKind)Record[Idx++]) {
   case VarNotTemplate:
     // Only true variables (not parameters or implicit parameters) can be merged
-    if (VD->getKind() != Decl::ParmVar && VD->getKind() != Decl::ImplicitParam)
+    if (VD->getKind() != Decl::ParmVar && VD->getKind() != Decl::ImplicitParam &&
+        !isa<VarTemplateSpecializationDecl>(VD))
       mergeRedeclarable(VD, Redecl);
     break;
   case VarTemplate:
@@ -1438,7 +1439,9 @@ ASTDeclReader::VisitCXXRecordDeclImpl(CX
   };
   switch ((CXXRecKind)Record[Idx++]) {
   case CXXRecNotTemplate:
-    mergeRedeclarable(D, Redecl);
+    // Merged when we merge the folding set entry in the primary template.
+    if (!isa<ClassTemplateSpecializationDecl>(D))
+      mergeRedeclarable(D, Redecl);
     break;
   case CXXRecTemplate: {
     // Merged when we merge the template.

Modified: cfe/trunk/test/Modules/Inputs/cxx-templates-a.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/cxx-templates-a.h?rev=212788&r1=212787&r2=212788&view=diff
==============================================================================
--- cfe/trunk/test/Modules/Inputs/cxx-templates-a.h (original)
+++ cfe/trunk/test/Modules/Inputs/cxx-templates-a.h Thu Jul 10 19:20:06 2014
@@ -63,3 +63,7 @@ template<> struct WithExplicitSpecializa
     return n;
   }
 };
+
+template<typename T> template<typename U>
+constexpr int Outer<T>::Inner<U>::f() { return 1; }
+static_assert(Outer<int>::Inner<int>::f() == 1, "");

Modified: cfe/trunk/test/Modules/Inputs/cxx-templates-b.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/cxx-templates-b.h?rev=212788&r1=212787&r2=212788&view=diff
==============================================================================
--- cfe/trunk/test/Modules/Inputs/cxx-templates-b.h (original)
+++ cfe/trunk/test/Modules/Inputs/cxx-templates-b.h Thu Jul 10 19:20:06 2014
@@ -20,6 +20,10 @@ extern DefinedInCommon &defined_in_commo
 template<int> struct MergeTemplates;
 MergeTemplates<0> *merge_templates_b;
 
+template<typename T> template<typename U>
+constexpr int Outer<T>::Inner<U>::g() { return 2; }
+static_assert(Outer<int>::Inner<int>::g() == 2, "");
+
 @import cxx_templates_b_impl;
 
 template<typename T, typename> struct Identity { typedef T type; };

Modified: cfe/trunk/test/Modules/Inputs/cxx-templates-common.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/cxx-templates-common.h?rev=212788&r1=212787&r2=212788&view=diff
==============================================================================
--- cfe/trunk/test/Modules/Inputs/cxx-templates-common.h (original)
+++ cfe/trunk/test/Modules/Inputs/cxx-templates-common.h Thu Jul 10 19:20:06 2014
@@ -26,8 +26,8 @@ template<typename T> struct TemplateInst
 
 template<typename T> struct Outer {
   template<typename U> struct Inner {
-    void f();
-    void g();
+    static constexpr int f();
+    static constexpr int g();
   };
 };
 

Modified: cfe/trunk/test/Modules/cxx-templates.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/cxx-templates.cpp?rev=212788&r1=212787&r2=212788&view=diff
==============================================================================
--- cfe/trunk/test/Modules/cxx-templates.cpp (original)
+++ cfe/trunk/test/Modules/cxx-templates.cpp Thu Jul 10 19:20:06 2014
@@ -107,6 +107,9 @@ void g() {
   int &q = WithExplicitSpecializationUse().inner_template<int>();
 }
 
+static_assert(Outer<int>::Inner<int>::f() == 1, "");
+static_assert(Outer<int>::Inner<int>::g() == 2, "");
+
 RedeclaredAsFriend<int> raf1;
 RedeclareTemplateAsFriend<double> rtaf;
 RedeclaredAsFriend<double> raf2;