From b0e33d499d97b69f795cb53f8934bcd134a56b5a Mon Sep 17 00:00:00 2001
From: Axel Naumann <Axel.Naumann@cern.ch>
Date: Mon, 1 Oct 2012 09:18:00 +0000
Subject: [PATCH] Also merge template redeclarations. Don't require
 specializations (of existing and read template) to be unique.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164931 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Serialization/ASTReaderDecl.cpp      | 20 +++++++++++++-------
 test/Modules/Inputs/redecl-merge-left.h  |  7 +++++++
 test/Modules/Inputs/redecl-merge-right.h |  7 +++++++
 test/Modules/redecl-merge.m              |  3 +++
 4 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 843893d90f..fb4192f86a 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1312,10 +1312,12 @@ ASTDeclReader::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
         D->setMemberSpecialization();
     }
   }
-     
+
   VisitTemplateDecl(D);
   D->IdentifierNamespace = Record[Idx++];
-  
+
+  mergeRedeclarable(D, Redecl);
+
   return Redecl;
 }
 
@@ -1402,9 +1404,9 @@ void ASTDeclReader::VisitClassTemplateSpecializationDecl(
     if (D->isCanonicalDecl()) { // It's kept in the folding set.
       if (ClassTemplatePartialSpecializationDecl *Partial
                         = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) {
-       CanonPattern->getCommonPtr()->PartialSpecializations.InsertNode(Partial);
+  CanonPattern->getCommonPtr()->PartialSpecializations.GetOrInsertNode(Partial);
       } else {
-        CanonPattern->getCommonPtr()->Specializations.InsertNode(D);
+        CanonPattern->getCommonPtr()->Specializations.GetOrInsertNode(D);
       }
     }
   }
@@ -1747,7 +1749,7 @@ static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
     return (FuncX->getLinkage() == FuncY->getLinkage()) &&
       FuncX->getASTContext().hasSameType(FuncX->getType(), FuncY->getType());
   }
-  
+
   // Variables with the same type and linkage match.
   if (VarDecl *VarX = dyn_cast<VarDecl>(X)) {
     VarDecl *VarY = cast<VarDecl>(Y);
@@ -1760,7 +1762,11 @@ static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
     NamespaceDecl *NamespaceY = cast<NamespaceDecl>(Y);
     return NamespaceX->isInline() == NamespaceY->isInline();
   }
-      
+
+  // Identical template names and kinds match.
+  if (isa<TemplateDecl>(X))
+    return true;
+
   // FIXME: Many other cases to implement.
   return false;
 }
@@ -2296,7 +2302,7 @@ void ASTReader::loadPendingDeclChain(serialization::GlobalDeclID ID) {
   }
   MergedDeclsMap::iterator MergedPos = combineStoredMergedDecls(CanonDecl, ID);
   if (MergedPos != MergedDecls.end())
-    SearchDecls.append(MergedPos->second.begin(), MergedPos->second.end());  
+    SearchDecls.append(MergedPos->second.begin(), MergedPos->second.end());
   
   // Build up the list of redeclarations.
   RedeclChainVisitor Visitor(*this, SearchDecls, RedeclsDeserialized, CanonID);
diff --git a/test/Modules/Inputs/redecl-merge-left.h b/test/Modules/Inputs/redecl-merge-left.h
index 4bdd01570f..a6ea6024c8 100644
--- a/test/Modules/Inputs/redecl-merge-left.h
+++ b/test/Modules/Inputs/redecl-merge-left.h
@@ -88,6 +88,13 @@ template<> class List<bool> {
 public:
   void push_back(int);
 };
+
+namespace N {
+template<typename T> class Set {
+public:
+  void insert(T);
+};
+}
 #endif
 
 // Make sure this doesn't introduce an ambiguity-creating 'id' at the
diff --git a/test/Modules/Inputs/redecl-merge-right.h b/test/Modules/Inputs/redecl-merge-right.h
index 695327674f..2e05c035c5 100644
--- a/test/Modules/Inputs/redecl-merge-right.h
+++ b/test/Modules/Inputs/redecl-merge-right.h
@@ -89,6 +89,13 @@ template<> class List<bool> {
 public:
   void push_back(int);
 };
+
+namespace N {
+  template<typename T> class Set {
+  public:
+    void insert(T);
+  };
+}
 #endif
 
 int ONE;
diff --git a/test/Modules/redecl-merge.m b/test/Modules/redecl-merge.m
index 0e5cd4ac37..96b0b47565 100644
--- a/test/Modules/redecl-merge.m
+++ b/test/Modules/redecl-merge.m
@@ -153,6 +153,9 @@ void testVector() {
 
   List<bool> list_bool;
   list_bool.push_back(false);
+
+  N::Set<char> set_char;
+  set_char.insert('A');
 }
 #endif
 
-- 
2.40.0