[Sema] Actually map a variable template specialization from pattern to instantiation

We were previously just using a specialization in the class template instead of
creating a new specialization in the class instantiation.

Fixes llvm.org/PR42779.

Differential revision: https://reviews.llvm.org/D65359

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@367367 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 1174a11f6cebb492be59161b1f3a7b71b85ff460..92244cdf088233e118b9b628422a21fd804540ce 100644 (file)
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -8191,6 +8191,11 @@ public:
                              LocalInstantiationScope *StartingScope,
                              bool InstantiatingVarTemplate = false,
                              VarTemplateSpecializationDecl *PrevVTSD = nullptr);
+
+  VarDecl *getVarTemplateSpecialization(
+      VarTemplateDecl *VarTempl, const TemplateArgumentListInfo *TemplateArgs,
+      const DeclarationNameInfo &MemberNameInfo, SourceLocation TemplateKWLoc);
+
   void InstantiateVariableInitializer(
       VarDecl *Var, VarDecl *OldVar,
       const MultiLevelTemplateArgumentList &TemplateArgs);

diff --git a/lib/Sema/SemaExprMember.cpp b/lib/Sema/SemaExprMember.cpp
index c856e37e99e7a0ebb481d5ddfd24d6e0dd4b1000..3ba77f19a6b8a0503647a7310337ee9ec24b8f8d 100644 (file)
--- a/lib/Sema/SemaExprMember.cpp
+++ b/lib/Sema/SemaExprMember.cpp
@@ -934,19 +934,19 @@ static bool IsInFnTryBlockHandler(const Scope *S) {
   return false;
 }
 
-static VarDecl *
-getVarTemplateSpecialization(Sema &S, VarTemplateDecl *VarTempl,
+VarDecl *
+Sema::getVarTemplateSpecialization(VarTemplateDecl *VarTempl,
                       const TemplateArgumentListInfo *TemplateArgs,
                       const DeclarationNameInfo &MemberNameInfo,
                       SourceLocation TemplateKWLoc) {
   if (!TemplateArgs) {
-    S.diagnoseMissingTemplateArguments(TemplateName(VarTempl),
-                                       MemberNameInfo.getBeginLoc());
+    diagnoseMissingTemplateArguments(TemplateName(VarTempl),
+                                     MemberNameInfo.getBeginLoc());
     return nullptr;
   }
 
-  DeclResult VDecl = S.CheckVarTemplateId(
-      VarTempl, TemplateKWLoc, MemberNameInfo.getLoc(), *TemplateArgs);
+  DeclResult VDecl = CheckVarTemplateId(VarTempl, TemplateKWLoc,
+                                        MemberNameInfo.getLoc(), *TemplateArgs);
   if (VDecl.isInvalid())
     return nullptr;
   VarDecl *Var = cast<VarDecl>(VDecl.get());
@@ -1095,7 +1095,7 @@ Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType,
              "How did we get template arguments here sans a variable template");
       if (isa<VarTemplateDecl>(MemberDecl)) {
         MemberDecl = getVarTemplateSpecialization(
-            *this, cast<VarTemplateDecl>(MemberDecl), TemplateArgs,
+            cast<VarTemplateDecl>(MemberDecl), TemplateArgs,
             R.getLookupNameInfo(), TemplateKWLoc);
         if (!MemberDecl)
           return ExprError();
@@ -1160,7 +1160,7 @@ Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType,
   }
   if (VarTemplateDecl *VarTempl = dyn_cast<VarTemplateDecl>(MemberDecl)) {
     if (VarDecl *Var = getVarTemplateSpecialization(
-            *this, VarTempl, TemplateArgs, MemberNameInfo, TemplateKWLoc))
+            VarTempl, TemplateArgs, MemberNameInfo, TemplateKWLoc))
       return BuildMemberExpr(
           BaseExpr, IsArrow, OpLoc, &SS, TemplateKWLoc, Var, FoundDecl,
           /*HadMultipleCandidates=*/false, MemberNameInfo,

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 67343d11d33305a5b8a717ae25d8c825678c5781..25d0db803983880945b07bf1ff6507e46edd7bff 100644 (file)
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -5217,11 +5217,11 @@ DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC,
 /// template struct X<int>;
 /// \endcode
 ///
-/// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
-/// \p EnumConstantDecl for \p KnownValue (which refers to
-/// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
-/// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
-/// this mapping from within the instantiation of <tt>X<int></tt>.
+/// In the instantiation of X<int>::getKind(), we need to map the \p
+/// EnumConstantDecl for \p KnownValue (which refers to
+/// X<T>::<Kind>::KnownValue) to its instantiation (X<int>::<Kind>::KnownValue).
+/// \p FindInstantiatedDecl performs this mapping from within the instantiation
+/// of X<int>.
 NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
                           const MultiLevelTemplateArgumentList &TemplateArgs,
                           bool FindingInstantiatedContext) {
@@ -5312,20 +5312,6 @@ NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
     return cast<LabelDecl>(Inst);
   }
 
-  // For variable template specializations, update those that are still
-  // type-dependent.
-  if (VarTemplateSpecializationDecl *VarSpec =
-          dyn_cast<VarTemplateSpecializationDecl>(D)) {
-    bool InstantiationDependent = false;
-    const TemplateArgumentListInfo &VarTemplateArgs =
-        VarSpec->getTemplateArgsInfo();
-    if (TemplateSpecializationType::anyDependentTemplateArguments(
-            VarTemplateArgs, InstantiationDependent))
-      D = cast<NamedDecl>(
-          SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
-    return D;
-  }
-
   if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
     if (!Record->isDependentContext())
       return D;
@@ -5450,11 +5436,23 @@ NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
     // find it. Does that ever matter?
     if (auto Name = D->getDeclName()) {
       DeclarationNameInfo NameInfo(Name, D->getLocation());
-      Name = SubstDeclarationNameInfo(NameInfo, TemplateArgs).getName();
+      DeclarationNameInfo NewNameInfo =
+          SubstDeclarationNameInfo(NameInfo, TemplateArgs);
+      Name = NewNameInfo.getName();
       if (!Name)
         return nullptr;
       DeclContext::lookup_result Found = ParentDC->lookup(Name);
-      Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
+
+      if (auto *VTSD = dyn_cast<VarTemplateSpecializationDecl>(D)) {
+        VarTemplateDecl *Templ = cast_or_null<VarTemplateDecl>(
+            findInstantiationOf(Context, VTSD->getSpecializedTemplate(),
+                                Found.begin(), Found.end()));
+        if (!Templ)
+          return nullptr;
+        Result = getVarTemplateSpecialization(
+            Templ, &VTSD->getTemplateArgsInfo(), NewNameInfo, SourceLocation());
+      } else
+        Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
     } else {
       // Since we don't have a name for the entity we're looking for,
       // our only option is to walk through all of the declarations to

diff --git a/test/SemaCXX/cxx1y-variable-templates_in_class.cpp b/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
index b09305d7a0c15558ba6fed7271899ff4d206ebf2..ecdd54f35fc3278ba43119d00e4cbdb10a9ff373 100644 (file)
--- a/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
+++ b/test/SemaCXX/cxx1y-variable-templates_in_class.cpp
@@ -395,3 +395,32 @@ namespace dependent_static_var_template {
   }
   int &t = B::template n; // expected-error {{use of variable template 'n' requires template arguments}}
 }
+
+#ifndef PRECXX11
+namespace template_vars_in_template {
+template <int> struct TakesInt {};
+
+template <class T2>
+struct S {
+  template <class T1>
+  static constexpr int v = 42;
+
+  template <class T>
+  void mf() {
+    constexpr int val = v<T>;
+  }
+
+  void mf2() {
+    constexpr int val = v<char>;
+    TakesInt<val> ti;
+    (void)ti.x; // expected-error{{no member named 'x' in 'template_vars_in_template::TakesInt<42>'}}
+  }
+};
+
+void useit() {
+  S<int> x;
+  x.mf<double>();
+  x.mf2(); // expected-note{{in instantiation of member function 'template_vars_in_template::S<int>::mf2' requested here}}
+}
+}
+#endif