Improve our handling of local instantiation scopes in two related ways:

  - When substituting template arguments as part of template argument
    deduction, introduce a new local instantiation scope.
  - When substituting into a function prototype type, introduce a new
    "temporary" local instantiation scope that merges with its outer
    scope but also keeps track of any additions it makes, removing
    them when we exit that scope.

Fixes PR6700, where we were getting too much mixing of local
instantiation scopes due to template argument deduction that
substituted results into function types.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@99509 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index ba6d38f849a5751431299a926d550233bad22337..7e2e6143965c34e9d6cd830adf140433b3f39fe3 100644 (file)
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -3487,15 +3487,27 @@ public:
     /// \brief Whether we have already exited this scope.
     bool Exited;
 
+    /// \brief Whether this scope is temporary, meaning that we should
+    /// remove any additions we make once we exit this
+    /// scope. Temporary scopes are always combined with their outer
+    /// scopes.
+    bool Temporary;
+
+    /// \brief List of the declarations that we have added into this
+    /// temporary scope. They will be removed when we exit the
+    /// temporary scope.
+    llvm::SmallVector<const Decl *, 4> AddedTemporaryDecls;
+
     // This class is non-copyable
     LocalInstantiationScope(const LocalInstantiationScope &);
     LocalInstantiationScope &operator=(const LocalInstantiationScope &);
 
   public:
-    LocalInstantiationScope(Sema &SemaRef, bool CombineWithOuterScope = false)
+    LocalInstantiationScope(Sema &SemaRef, bool CombineWithOuterScope = false,
+                            bool Temporary = false)
       : SemaRef(SemaRef), Outer(SemaRef.CurrentInstantiationScope), 
-        Exited(false) {
-      if (!CombineWithOuterScope)
+        Exited(false), Temporary(Temporary) {
+      if (!CombineWithOuterScope && !Temporary)
         SemaRef.CurrentInstantiationScope = this;
       else
         assert(SemaRef.CurrentInstantiationScope && 
@@ -3503,8 +3515,11 @@ public:
     }
 
     ~LocalInstantiationScope() {
-      if (!Exited)
+      if (!Exited) {
         SemaRef.CurrentInstantiationScope = Outer;
+        for (unsigned I = 0, N = AddedTemporaryDecls.size(); I != N; ++I)
+          LocalDecls.erase(AddedTemporaryDecls[I]);
+      }
     }
 
     /// \brief Exit this local instantiation scope early.
@@ -3537,6 +3552,10 @@ public:
     void InstantiatedLocal(const Decl *D, Decl *Inst) {
       Decl *&Stored = LocalDecls[D];
       assert((!Stored || Stored == Inst) && "Already instantiated this local");
+
+      if (Temporary && !Stored)
+        AddedTemporaryDecls.push_back(D);
+
       Stored = Inst;
     }
   };

diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 326519d3a3781e3f338506542b65d3f3839cff7b..3a8ed5089426f4542269a21e8718dd6824217e9c 100644 (file)
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -987,13 +987,7 @@ Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
       Decl *Param
         = const_cast<NamedDecl *>(
                                 Partial->getTemplateParameters()->getParam(I));
-      if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
-        Info.Param = TTP;
-      else if (NonTypeTemplateParmDecl *NTTP
-                 = dyn_cast<NonTypeTemplateParmDecl>(Param))
-        Info.Param = NTTP;
-      else
-        Info.Param = cast<TemplateTemplateParmDecl>(Param);
+      Info.Param = makeTemplateParameter(Param);
       return TDK_Incomplete;
     }
 
@@ -1010,6 +1004,7 @@ Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
   // verify that the instantiated template arguments are both valid
   // and are equivalent to the template arguments originally provided
   // to the class template.
+  Sema::LocalInstantiationScope InstScope(*this);
   ClassTemplateDecl *ClassTemplate = Partial->getSpecializedTemplate();
   const TemplateArgumentLoc *PartialTemplateArgs
     = Partial->getTemplateArgsAsWritten();
@@ -1458,6 +1453,7 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
 
   // The types of the parameters from which we will perform template argument
   // deduction.
+  Sema::LocalInstantiationScope InstScope(*this);
   TemplateParameterList *TemplateParams
     = FunctionTemplate->getTemplateParameters();
   llvm::SmallVector<TemplateArgument, 4> Deduced;
@@ -1612,6 +1608,7 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
   QualType FunctionType = Function->getType();
 
   // Substitute any explicit template arguments.
+  Sema::LocalInstantiationScope InstScope(*this);
   llvm::SmallVector<TemplateArgument, 4> Deduced;
   llvm::SmallVector<QualType, 4> ParamTypes;
   if (ExplicitTemplateArgs) {
@@ -1739,6 +1736,7 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
   // modulo the various allowed differences.
 
   // Finish template argument deduction.
+  Sema::LocalInstantiationScope InstScope(*this);
   FunctionDecl *Spec = 0;
   TemplateDeductionResult Result
     = FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, Spec, Info);

diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index ac1bf7219c555224da05f1d97846341f01c8bd35..89a660c79f9d0a644999e86e181d192c5aabebee 100644 (file)
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -873,8 +873,11 @@ TemplateInstantiator::TransformFunctionTypeParams(FunctionProtoTypeLoc TL,
                                   llvm::SmallVectorImpl<QualType> &PTypes,
                                llvm::SmallVectorImpl<ParmVarDecl*> &PVars) {
   // Create a local instantiation scope for the parameters.
-  Sema::LocalInstantiationScope
-    Scope(SemaRef, SemaRef.CurrentInstantiationScope != 0);
+  // FIXME: When we implement the C++0x late-specified return type, 
+  // we will need to move this scope out to the function type itself.
+  bool IsTemporaryScope = (SemaRef.CurrentInstantiationScope != 0);
+  Sema::LocalInstantiationScope Scope(SemaRef, IsTemporaryScope, 
+                                      IsTemporaryScope);
 
   if (TreeTransform<TemplateInstantiator>::
         TransformFunctionTypeParams(TL, PTypes, PVars))

diff --git a/test/SemaTemplate/instantiate-function-params.cpp b/test/SemaTemplate/instantiate-function-params.cpp
index a574dbb787ef83dc09795a314e729217156e33ef..dfba14a97c8cb79b890e401cdedb146a7ca10d64 100644 (file)
--- a/test/SemaTemplate/instantiate-function-params.cpp
+++ b/test/SemaTemplate/instantiate-function-params.cpp
@@ -31,3 +31,14 @@ template < typename TT > struct ForwardIterator                              : I
 };
 typedef instantiate< &requirement_<void(*)(ForwardIterator<char*> x)>::failed> boost_concept_checkX; // expected-error{{no member named}} \
 // expected-note 6{{in instantiation}}
+
+template<typename T> struct X0 { };
+template<typename R, typename A1> struct X0<R(A1 param)> { };
+
+template<typename T, typename A1, typename A2>
+void instF0(X0<T(A1)> x0a, X0<T(A2)> x0b) {
+  X0<T(A1)> x0c;
+  X0<T(A2)> x0d;
+}
+
+template void instF0<int, int, float>(X0<int(int)>, X0<int(float)>);