From 7b3b95a9485059b196896accc0144fd0bc31ff2c Mon Sep 17 00:00:00 2001
From: Axel Naumann <Axel.Naumann@cern.ch>
Date: Mon, 1 Oct 2012 07:34:47 +0000
Subject: [PATCH] Bring ASTReader and Writer into sync for the case where a
 canonical template specialization was written, which is non-canonical at the
 time of reading: force the reading of the ClassTemplateDecl if it was
 written. The easiest way out is to store whether the decl was canonical at
 the time of writing. Add test.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164927 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Serialization/ASTReaderDecl.cpp      | 17 ++++++++++-------
 lib/Serialization/ASTWriterDecl.cpp      |  1 +
 test/Modules/Inputs/redecl-merge-left.h  |  6 ++++++
 test/Modules/Inputs/redecl-merge-right.h |  6 ++++++
 test/Modules/Inputs/redecl-merge-top.h   |  5 +++++
 test/Modules/redecl-merge.m              |  3 +++
 6 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index c9788a3216..843893d90f 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1395,14 +1395,17 @@ void ASTDeclReader::VisitClassTemplateSpecializationDecl(
                                                      TemplArgs.size());
   D->PointOfInstantiation = ReadSourceLocation(Record, Idx);
   D->SpecializationKind = (TemplateSpecializationKind)Record[Idx++];
-  
-  if (D->isCanonicalDecl()) { // It's kept in the folding set.
+
+  bool writtenAsCanonicalDecl = Record[Idx++];
+  if (writtenAsCanonicalDecl) {
     ClassTemplateDecl *CanonPattern = ReadDeclAs<ClassTemplateDecl>(Record,Idx);
-    if (ClassTemplatePartialSpecializationDecl *Partial
-                       = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) {
-      CanonPattern->getCommonPtr()->PartialSpecializations.InsertNode(Partial);
-    } else {
-      CanonPattern->getCommonPtr()->Specializations.InsertNode(D);
+    if (D->isCanonicalDecl()) { // It's kept in the folding set.
+      if (ClassTemplatePartialSpecializationDecl *Partial
+                        = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) {
+       CanonPattern->getCommonPtr()->PartialSpecializations.InsertNode(Partial);
+      } else {
+        CanonPattern->getCommonPtr()->Specializations.InsertNode(D);
+      }
     }
   }
 }
diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index 7122bca969..0f9bb3824b 100644
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -1106,6 +1106,7 @@ void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
   Writer.AddTemplateArgumentList(&D->getTemplateArgs(), Record);
   Writer.AddSourceLocation(D->getPointOfInstantiation(), Record);
   Record.push_back(D->getSpecializationKind());
+  Record.push_back(D->isCanonicalDecl());
 
   if (D->isCanonicalDecl()) {
     // When reading, we'll add it to the folding set of the following template. 
diff --git a/test/Modules/Inputs/redecl-merge-left.h b/test/Modules/Inputs/redecl-merge-left.h
index b3a7ba83c1..4bdd01570f 100644
--- a/test/Modules/Inputs/redecl-merge-left.h
+++ b/test/Modules/Inputs/redecl-merge-left.h
@@ -82,6 +82,12 @@ extern double var3;
 template<typename T> class Vector;
 
 template<typename T> class Vector;
+
+template<typename T> class List;
+template<> class List<bool> {
+public:
+  void push_back(int);
+};
 #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 de7aa08cfb..695327674f 100644
--- a/test/Modules/Inputs/redecl-merge-right.h
+++ b/test/Modules/Inputs/redecl-merge-right.h
@@ -83,6 +83,12 @@ template<typename T> class Vector {
 public:
   void push_back(const T&);
 };
+
+template<typename T> class List;
+template<> class List<bool> {
+public:
+  void push_back(int);
+};
 #endif
 
 int ONE;
diff --git a/test/Modules/Inputs/redecl-merge-top.h b/test/Modules/Inputs/redecl-merge-top.h
index 519254ca22..7053936b2c 100644
--- a/test/Modules/Inputs/redecl-merge-top.h
+++ b/test/Modules/Inputs/redecl-merge-top.h
@@ -17,4 +17,9 @@ struct S2;
 
 #ifdef __cplusplus
 template<typename T> class Vector;
+
+template<typename T> class List {
+public:
+  void push_back(T);
+};
 #endif
diff --git a/test/Modules/redecl-merge.m b/test/Modules/redecl-merge.m
index d7930aca2e..0e5cd4ac37 100644
--- a/test/Modules/redecl-merge.m
+++ b/test/Modules/redecl-merge.m
@@ -150,6 +150,9 @@ id<P3> p3;
 void testVector() {
   Vector<int> vec_int;
   vec_int.push_back(0);
+
+  List<bool> list_bool;
+  list_bool.push_back(false);
 }
 #endif
 
-- 
2.40.0