[modules] Track the described template in an alias declaration that is the

pattern of an alias template declaration. Use this to merge alias templates
properly when they're members of class template specializations.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216437 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index c8c118cbcfd19ecf0293fb6c4ead28ec604d6e64..083183525c69b5211f3cb711a17ca56d02da6bee 100644 (file)
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -43,6 +43,7 @@ class Stmt;
 class StringLiteral;
 class TemplateArgumentList;
 class TemplateParameterList;
+class TypeAliasTemplateDecl;
 class TypeLoc;
 class UnresolvedSetImpl;
 class VarTemplateDecl;
@@ -2492,9 +2493,13 @@ public:
 /// TypeAliasDecl - Represents the declaration of a typedef-name via a C++0x
 /// alias-declaration.
 class TypeAliasDecl : public TypedefNameDecl {
+  /// The template for which this is the pattern, if any.
+  TypeAliasTemplateDecl *Template;
+
   TypeAliasDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
                 SourceLocation IdLoc, IdentifierInfo *Id, TypeSourceInfo *TInfo)
-      : TypedefNameDecl(TypeAlias, C, DC, StartLoc, IdLoc, Id, TInfo) {}
+      : TypedefNameDecl(TypeAlias, C, DC, StartLoc, IdLoc, Id, TInfo),
+        Template(nullptr) {}
 
 public:
   static TypeAliasDecl *Create(ASTContext &C, DeclContext *DC,
@@ -2504,6 +2509,9 @@ public:
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
+  TypeAliasTemplateDecl *getDescribedAliasTemplate() const { return Template; }
+  void setDescribedAliasTemplate(TypeAliasTemplateDecl *TAT) { Template = TAT; }
+
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K == TypeAlias; }

diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 6a48162502cb670bb0f41a6270142d0bd1ebe634..82d06d126b2b45cf29fa0b96f5d4d684348ca38d 100644 (file)
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -8207,6 +8207,7 @@ Decl *Sema::ActOnAliasDeclaration(Scope *S,
       TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
                                     Name.Identifier, TemplateParams,
                                     NewTD);
+    NewTD->setDescribedAliasTemplate(NewDecl);
 
     NewDecl->setAccess(AS);
 

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index c27a2430415314290969ac2b21ddbc6a6cc1db9f..e9d95f2b2925ed0e1309b98c5ac1d5191beb609a 100644 (file)
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -363,6 +363,7 @@ TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
   TypeAliasTemplateDecl *Inst
     = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
                                     D->getDeclName(), InstParams, AliasInst);
+  AliasInst->setDescribedAliasTemplate(Inst);
   if (PrevAliasTemplate)
     Inst->setPreviousDecl(PrevAliasTemplate);
 

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 2503500dcd47a1d7f5e30d7ab76e756987fef2a9..5f7a93f13202692c9f1b582a3c5530a867a2342a 100644 (file)
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -234,7 +234,7 @@ namespace clang {
     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
     void VisitTypeDecl(TypeDecl *TD);
-    void VisitTypedefNameDecl(TypedefNameDecl *TD);
+    RedeclarableResult VisitTypedefNameDecl(TypedefNameDecl *TD);
     void VisitTypedefDecl(TypedefDecl *TD);
     void VisitTypeAliasDecl(TypeAliasDecl *TD);
     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
@@ -456,7 +456,8 @@ void ASTDeclReader::VisitTypeDecl(TypeDecl *TD) {
   TypeIDForTypeDecl = Reader.getGlobalTypeID(F, Record[Idx++]);
 }
 
-void ASTDeclReader::VisitTypedefNameDecl(TypedefNameDecl *TD) {
+ASTDeclReader::RedeclarableResult
+ASTDeclReader::VisitTypedefNameDecl(TypedefNameDecl *TD) {
   RedeclarableResult Redecl = VisitRedeclarable(TD);
   VisitTypeDecl(TD);
   TypeSourceInfo *TInfo = GetTypeSourceInfo(Record, Idx);
@@ -465,15 +466,21 @@ void ASTDeclReader::VisitTypedefNameDecl(TypedefNameDecl *TD) {
     TD->setModedTypeSourceInfo(TInfo, modedT);
   } else
     TD->setTypeSourceInfo(TInfo);
-  mergeRedeclarable(TD, Redecl);
+  return Redecl;
 }
 
 void ASTDeclReader::VisitTypedefDecl(TypedefDecl *TD) {
-  VisitTypedefNameDecl(TD);
+  RedeclarableResult Redecl = VisitTypedefNameDecl(TD);
+  mergeRedeclarable(TD, Redecl);
 }
 
 void ASTDeclReader::VisitTypeAliasDecl(TypeAliasDecl *TD) {
-  VisitTypedefNameDecl(TD);
+  RedeclarableResult Redecl = VisitTypedefNameDecl(TD);
+  if (auto *Template = ReadDeclAs<TypeAliasTemplateDecl>(Record, Idx))
+    // Merged when we merge the template.
+    TD->setDescribedAliasTemplate(Template);
+  else
+    mergeRedeclarable(TD, Redecl);
 }
 
 ASTDeclReader::RedeclarableResult ASTDeclReader::VisitTagDecl(TagDecl *TD) {

diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index dca7796c029a0255c619f31b72d3a26b28a57d72..cd8f7ddf599a701138ae5e8c3fdee9e824d1a991 100644 (file)
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -236,6 +236,7 @@ void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
 
 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
   VisitTypedefNameDecl(D);
+  Writer.AddDeclRef(D->getDescribedAliasTemplate(), Record);
   Code = serialization::DECL_TYPEALIAS;
 }
 

diff --git a/test/Modules/Inputs/cxx-templates-a.h b/test/Modules/Inputs/cxx-templates-a.h
index f3150398e7a988ebb651fb1ae9ea030972a4255b..928a544fc4dc8dc64b32d35bfe3f02cd3e33e4e1 100644 (file)
--- a/test/Modules/Inputs/cxx-templates-a.h
+++ b/test/Modules/Inputs/cxx-templates-a.h
@@ -85,3 +85,5 @@ template<typename T> struct PartiallyInstantiatePartialSpec<T*> {
   static T *bar() { return reinterpret_cast<T*>(0); }
 };
 typedef PartiallyInstantiatePartialSpec<int*> PartiallyInstantiatePartialSpecHelper;
+
+void InstantiateWithAliasTemplate(WithAliasTemplate<int>::X<char>);

diff --git a/test/Modules/Inputs/cxx-templates-b.h b/test/Modules/Inputs/cxx-templates-b.h
index 8b97d22a370cd110115fc1099d80510144aaccc3..cfaea282df03a6ac9ed714f7ca3d741857ed2220 100644 (file)
--- a/test/Modules/Inputs/cxx-templates-b.h
+++ b/test/Modules/Inputs/cxx-templates-b.h
@@ -69,6 +69,8 @@ template<> struct MergeSpecializations<double> {
 
 template<typename U> using AliasTemplate = U;
 
+void InstantiateWithAliasTemplate(WithAliasTemplate<int>::X<char>);
+
 @import cxx_templates_a;
 template<typename T> void UseDefinedInBImplIndirectly(T &v) {
   PerformDelayedLookup(v);

diff --git a/test/Modules/Inputs/cxx-templates-common.h b/test/Modules/Inputs/cxx-templates-common.h
index f3c9022309110ee7cf51d92cecf2ac2c32d80ab7..d729c6edf4c1cbac0b070a16bc9ce9824497e1e0 100644 (file)
--- a/test/Modules/Inputs/cxx-templates-common.h
+++ b/test/Modules/Inputs/cxx-templates-common.h
@@ -41,4 +41,8 @@ typedef WithExplicitSpecialization<int> WithExplicitSpecializationUse;
 
 template<typename T> struct WithImplicitSpecialMembers { int n; };
 
+template<typename T> struct WithAliasTemplate {
+  template<typename> using X = T;
+};
+
 #include "cxx-templates-textual.h"

diff --git a/test/Modules/cxx-templates.cpp b/test/Modules/cxx-templates.cpp
index fedaa03ef4fc5426c7738a825c5a29017de0b27b..d0a6c0f9e5d855f9ef3eeefe13ad25d8a9776591 100644 (file)
--- a/test/Modules/cxx-templates.cpp
+++ b/test/Modules/cxx-templates.cpp
@@ -143,6 +143,8 @@ MergeSpecializations<double>::explicitly_specialized_in_b spec_in_b_2;
 MergeSpecializations<bool>::explicitly_specialized_in_c spec_in_c_2;
 #endif
 
+using AliasTemplateMergingTest = WithAliasTemplate<int>::X<char>;
+
 @import cxx_templates_common;
 
 typedef SomeTemplate<int*> SomeTemplateIntPtr;