Vendor import of clang trunk r161861:

http://llvm.org/svn/llvm-project/cfe/trunk@161861

1 files changed, 190 insertions, 48 deletions

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 51ce2a1..c8e4501 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -354,12 +354,14 @@ void Sema::LookupTemplateName(LookupResult &Found,
     return;
   }
 
-  if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope) {
-    // C++ [basic.lookup.classref]p1:
+  if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope &&
+      !(getLangOpts().CPlusPlus0x && !Found.empty())) {
+    // C++03 [basic.lookup.classref]p1:
     //   [...] If the lookup in the class of the object expression finds a
     //   template, the name is also looked up in the context of the entire
     //   postfix-expression and [...]
     //
+    // Note: C++11 does not perform this second lookup.
     LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(),
                             LookupOrdinaryName);
     LookupName(FoundOuter, S);
@@ -743,7 +745,7 @@ Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
 }
 
 /// ActOnTemplateTemplateParameter - Called when a C++ template template
-/// parameter (e.g. T in template <template <typename> class T> class array)
+/// parameter (e.g. T in template <template \<typename> class T> class array)
 /// has been parsed. S is the current scope.
 Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
                                            SourceLocation TmpLoc,
@@ -865,9 +867,13 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
     return true;
   }
 
-  // Find any previous declaration with this name.
+  // Find any previous declaration with this name. For a friend with no
+  // scope explicitly specified, we only look for tag declarations (per
+  // C++11 [basic.lookup.elab]p2).
   DeclContext *SemanticContext;
-  LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName,
+  LookupResult Previous(*this, Name, NameLoc,
+                        (SS.isEmpty() && TUK == TUK_Friend)
+                          ? LookupTagName : LookupOrdinaryName,
                         ForRedeclaration);
   if (SS.isNotEmpty() && !SS.isInvalid()) {
     SemanticContext = computeDeclContext(SS, true);
@@ -893,7 +899,7 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
         Invalid = true;
     } else if (TUK != TUK_Friend && TUK != TUK_Reference)
       diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc);
-        
+
     LookupQualifiedName(Previous, SemanticContext);
   } else {
     SemanticContext = CurContext;
@@ -948,22 +954,32 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
         // declaration.
         PrevDecl = PrevClassTemplate = 0;
         SemanticContext = OutermostContext;
-      }
-    }
 
-    if (CurContext->isDependentContext()) {
-      // If this is a dependent context, we don't want to link the friend
-      // class template to the template in scope, because that would perform
-      // checking of the template parameter lists that can't be performed
-      // until the outer context is instantiated.
-      PrevDecl = PrevClassTemplate = 0;
+        // Check that the chosen semantic context doesn't already contain a
+        // declaration of this name as a non-tag type.
+        LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName,
+                              ForRedeclaration);
+        DeclContext *LookupContext = SemanticContext;
+        while (LookupContext->isTransparentContext())
+          LookupContext = LookupContext->getLookupParent();
+        LookupQualifiedName(Previous, LookupContext);
+
+        if (Previous.isAmbiguous())
+          return true;
+
+        if (Previous.begin() != Previous.end())
+          PrevDecl = (*Previous.begin())->getUnderlyingDecl();
+      }
     }
   } else if (PrevDecl && !isDeclInScope(PrevDecl, SemanticContext, S))
     PrevDecl = PrevClassTemplate = 0;
 
   if (PrevClassTemplate) {
-    // Ensure that the template parameter lists are compatible.
-    if (!TemplateParameterListsAreEqual(TemplateParams,
+    // Ensure that the template parameter lists are compatible. Skip this check
+    // for a friend in a dependent context: the template parameter list itself
+    // could be dependent.
+    if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
+        !TemplateParameterListsAreEqual(TemplateParams,
                                    PrevClassTemplate->getTemplateParameters(),
                                         /*Complain=*/true,
                                         TPL_TemplateMatch))
@@ -1012,8 +1028,10 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
 
   // Check the template parameter list of this declaration, possibly
   // merging in the template parameter list from the previous class
-  // template declaration.
-  if (CheckTemplateParameterList(TemplateParams,
+  // template declaration. Skip this check for a friend in a dependent
+  // context, because the template parameter list might be dependent.
+  if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
+      CheckTemplateParameterList(TemplateParams,
             PrevClassTemplate? PrevClassTemplate->getTemplateParameters() : 0,
                                  (SS.isSet() && SemanticContext &&
                                   SemanticContext->isRecord() &&
@@ -1025,9 +1043,9 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
   if (SS.isSet()) {
     // If the name of the template was qualified, we must be defining the
     // template out-of-line.
-    if (!SS.isInvalid() && !Invalid && !PrevClassTemplate &&
-        !(TUK == TUK_Friend && CurContext->isDependentContext())) {
-      Diag(NameLoc, diag::err_member_def_does_not_match)
+    if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
+      Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
+                                      : diag::err_member_def_does_not_match)
         << Name << SemanticContext << SS.getRange();
       Invalid = true;
     }
@@ -1046,8 +1064,10 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
 
   // Add alignment attributes if necessary; these attributes are checked when
   // the ASTContext lays out the structure.
-  AddAlignmentAttributesForRecord(NewClass);
-  AddMsStructLayoutForRecord(NewClass);
+  if (TUK == TUK_Definition) {
+    AddAlignmentAttributesForRecord(NewClass);
+    AddMsStructLayoutForRecord(NewClass);
+  }
 
   ClassTemplateDecl *NewTemplate
     = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
@@ -1084,6 +1104,8 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
   if (Attr)
     ProcessDeclAttributeList(S, NewClass, Attr);
 
+  AddPushedVisibilityAttribute(NewClass);
+
   if (TUK != TUK_Friend)
     PushOnScopeChains(NewTemplate, S);
   else {
@@ -1116,6 +1138,11 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
     NewTemplate->setInvalidDecl();
     NewClass->setInvalidDecl();
   }
+  if (PrevClassTemplate)
+    mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
+
+  ActOnDocumentableDecl(NewTemplate);
+
   return NewTemplate;
 }
 
@@ -1972,6 +1999,8 @@ QualType Sema::CheckTemplateIdType(TemplateName Name,
       TemplateArgLists.addOuterTemplateArguments(0, 0);
 
     InstantiatingTemplate Inst(*this, TemplateLoc, Template);
+    if (Inst)
+      return QualType();
     CanonType = SubstType(Pattern->getUnderlyingType(),
                           TemplateArgLists, AliasTemplate->getLocation(),
                           AliasTemplate->getDeclName());
@@ -2420,6 +2449,43 @@ bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
 
     return true;
   }
+  case TemplateArgument::Expression: {
+    // We have a template type parameter but the template argument is an
+    // expression; see if maybe it is missing the "typename" keyword.
+    CXXScopeSpec SS;
+    DeclarationNameInfo NameInfo;
+
+    if (DeclRefExpr *ArgExpr = dyn_cast<DeclRefExpr>(Arg.getAsExpr())) {
+      SS.Adopt(ArgExpr->getQualifierLoc());
+      NameInfo = ArgExpr->getNameInfo();
+    } else if (DependentScopeDeclRefExpr *ArgExpr =
+               dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
+      SS.Adopt(ArgExpr->getQualifierLoc());
+      NameInfo = ArgExpr->getNameInfo();
+    } else if (CXXDependentScopeMemberExpr *ArgExpr =
+               dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
+      if (ArgExpr->isImplicitAccess()) {
+        SS.Adopt(ArgExpr->getQualifierLoc());
+        NameInfo = ArgExpr->getMemberNameInfo();
+      }
+    }
+
+    if (NameInfo.getName().isIdentifier()) {
+      LookupResult Result(*this, NameInfo, LookupOrdinaryName);
+      LookupParsedName(Result, CurScope, &SS);
+
+      if (Result.getAsSingle<TypeDecl>() ||
+          Result.getResultKind() ==
+            LookupResult::NotFoundInCurrentInstantiation) {
+        // FIXME: Add a FixIt and fix up the template argument for recovery.
+        SourceLocation Loc = AL.getSourceRange().getBegin();
+        Diag(Loc, diag::err_template_arg_must_be_type_suggest);
+        Diag(Param->getLocation(), diag::note_template_param_here);
+        return true;
+      }
+    }
+    // fallthrough
+  }
   default: {
     // We have a template type parameter but the template argument
     // is not a type.
@@ -2492,9 +2558,10 @@ SubstDefaultTemplateArgument(Sema &SemaRef,
       = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
 
     Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
-                                     Template, Converted.data(),
-                                     Converted.size(),
+                                     Template, Converted,
                                      SourceRange(TemplateLoc, RAngleLoc));
+    if (Inst)
+      return 0;
 
     Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
     ArgType = SemaRef.SubstType(ArgType, AllTemplateArgs,
@@ -2541,9 +2608,10 @@ SubstDefaultTemplateArgument(Sema &SemaRef,
     = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
 
   Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
-                                   Template, Converted.data(),
-                                   Converted.size(),
+                                   Template, Converted,
                                    SourceRange(TemplateLoc, RAngleLoc));
+  if (Inst)
+    return ExprError();
 
   Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
   EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
@@ -2590,9 +2658,10 @@ SubstDefaultTemplateArgument(Sema &SemaRef,
     = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
 
   Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
-                                   Template, Converted.data(),
-                                   Converted.size(),
+                                   Template, Converted,
                                    SourceRange(TemplateLoc, RAngleLoc));
+  if (Inst)
+    return TemplateName();
 
   Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
   // Substitute into the nested-name-specifier first, 
@@ -2724,8 +2793,10 @@ bool Sema::CheckTemplateArgument(NamedDecl *Param,
         !Template->getDeclContext()->isDependentContext()) {
       // Do substitution on the type of the non-type template parameter.
       InstantiatingTemplate Inst(*this, TemplateLoc, Template,
-                                 NTTP, Converted.data(), Converted.size(),
+                                 NTTP, Converted,
                                  SourceRange(TemplateLoc, RAngleLoc));
+      if (Inst)
+        return true;
 
       TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
                                         Converted.data(), Converted.size());
@@ -2856,8 +2927,10 @@ bool Sema::CheckTemplateArgument(NamedDecl *Param,
     // Set up a template instantiation context.
     LocalInstantiationScope Scope(*this);
     InstantiatingTemplate Inst(*this, TemplateLoc, Template,
-                               TempParm, Converted.data(), Converted.size(),
+                               TempParm, Converted,
                                SourceRange(TemplateLoc, RAngleLoc));
+    if (Inst)
+      return true;
 
     TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
                                       Converted.data(), Converted.size());
@@ -3086,9 +3159,11 @@ bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
 
     // Introduce an instantiation record that describes where we are using
     // the default template argument.
-    InstantiatingTemplate Instantiating(*this, RAngleLoc, Template, *Param,
-                                        Converted.data(), Converted.size(),
+    InstantiatingTemplate Instantiating(*this, RAngleLoc, Template,
+                                        *Param, Converted,
                                         SourceRange(TemplateLoc, RAngleLoc));
+    if (Instantiating)
+      return true;
 
     // Check the default template argument.
     if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
@@ -3574,6 +3649,7 @@ CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
   if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
     switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
     case NPV_NullPointer:
+      S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
       Converted = TemplateArgument((Decl *)0);
       return false;
 
@@ -3870,6 +3946,7 @@ static bool CheckTemplateArgumentPointerToMember(Sema &S,
   case NPV_Error:
     return true;
   case NPV_NullPointer:
+    S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
     Converted = TemplateArgument((Decl *)0);
     return false;
   case NPV_NotNullPointer:
@@ -4066,7 +4143,8 @@ ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
         IntegerType = Enum->getDecl()->getIntegerType();
       Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
 
-      Converted = TemplateArgument(Value, Context.getCanonicalType(ParamType));
+      Converted = TemplateArgument(Context, Value,
+                                   Context.getCanonicalType(ParamType));
       return ArgResult;
     }
 
@@ -4093,8 +4171,20 @@ ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
       Diag(Param->getLocation(), diag::note_template_param_here);
       return ExprError();
     } else if (!Arg->isValueDependent()) {
-      Arg = VerifyIntegerConstantExpression(Arg, &Value,
-        PDiag(diag::err_template_arg_not_ice) << ArgType, false).take();
+      class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
+        QualType T;
+        
+      public:
+        TmplArgICEDiagnoser(QualType T) : T(T) { }
+        
+        virtual void diagnoseNotICE(Sema &S, SourceLocation Loc,
+                                    SourceRange SR) {
+          S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR;
+        }
+      } Diagnoser(ArgType);
+
+      Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser,
+                                            false).take();
       if (!Arg)
         return ExprError();
     }
@@ -4180,7 +4270,7 @@ ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
       }
     }
 
-    Converted = TemplateArgument(Value,
+    Converted = TemplateArgument(Context, Value,
                                  ParamType->isEnumeralType() 
                                    ? Context.getCanonicalType(ParamType)
                                    : IntegerType);
@@ -4305,6 +4395,7 @@ ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
       return ExprError();
       
     case NPV_NullPointer:
+      Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
       Converted = TemplateArgument((Decl *)0);
       return Owned(Arg);;
     }
@@ -4497,13 +4588,13 @@ Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
       Kind = CharacterLiteral::Ascii;
 
     return Owned(new (Context) CharacterLiteral(
-                                            Arg.getAsIntegral()->getZExtValue(),
+                                            Arg.getAsIntegral().getZExtValue(),
                                             Kind, T, Loc));
   }
 
   if (T->isBooleanType())
     return Owned(new (Context) CXXBoolLiteralExpr(
-                                            Arg.getAsIntegral()->getBoolValue(),
+                                            Arg.getAsIntegral().getBoolValue(),
                                             T, Loc));
 
   if (T->isNullPtrType())
@@ -4518,7 +4609,7 @@ Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
   else
     BT = T;
 
-  Expr *E = IntegerLiteral::Create(Context, *Arg.getAsIntegral(), BT, Loc);
+  Expr *E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), BT, Loc);
   if (T->isEnumeralType()) {
     // FIXME: This is a hack. We need a better way to handle substituted
     // non-type template parameters.
@@ -5041,7 +5132,7 @@ static bool CheckNonTypeClassTemplatePartialSpecializationArgs(Sema &S,
 /// \param TemplateParams the template parameters of the primary class
 /// template.
 ///
-/// \param TemplateArg the template arguments of the class template
+/// \param TemplateArgs the template arguments of the class template
 /// partial specialization.
 ///
 /// \returns true if there was an error, false otherwise.
@@ -5481,7 +5572,9 @@ Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
 Decl *Sema::ActOnTemplateDeclarator(Scope *S,
                               MultiTemplateParamsArg TemplateParameterLists,
                                     Declarator &D) {
-  return HandleDeclarator(S, D, move(TemplateParameterLists));
+  Decl *NewDecl = HandleDeclarator(S, D, move(TemplateParameterLists));
+  ActOnDocumentableDecl(NewDecl);
+  return NewDecl;
 }
 
 Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope,
@@ -5719,14 +5812,17 @@ Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
 }
 
 /// \brief Perform semantic analysis for the given dependent function
-/// template specialization.  The only possible way to get a dependent
-/// function template specialization is with a friend declaration,
-/// like so:
+/// template specialization.
+///
+/// The only possible way to get a dependent function template specialization
+/// is with a friend declaration, like so:
 ///
-///   template <class T> void foo(T);
-///   template <class T> class A {
+/// \code
+///   template \<class T> void foo(T);
+///   template \<class T> class A {
 ///     friend void foo<>(T);
 ///   };
+/// \endcode
 ///
 /// There really isn't any useful analysis we can do here, so we
 /// just store the information.
@@ -6890,6 +6986,42 @@ Sema::ActOnTypenameType(Scope *S,
 }
 
 
+/// Determine whether this failed name lookup should be treated as being
+/// disabled by a usage of std::enable_if.
+static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
+                       SourceRange &CondRange) {
+  // We must be looking for a ::type...
+  if (!II.isStr("type"))
+    return false;
+
+  // ... within an explicitly-written template specialization...
+  if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
+    return false;
+  TypeLoc EnableIfTy = NNS.getTypeLoc();
+  TemplateSpecializationTypeLoc *EnableIfTSTLoc =
+    dyn_cast<TemplateSpecializationTypeLoc>(&EnableIfTy);
+  if (!EnableIfTSTLoc || EnableIfTSTLoc->getNumArgs() == 0)
+    return false;
+  const TemplateSpecializationType *EnableIfTST =
+    cast<TemplateSpecializationType>(EnableIfTSTLoc->getTypePtr());
+
+  // ... which names a complete class template declaration...
+  const TemplateDecl *EnableIfDecl =
+    EnableIfTST->getTemplateName().getAsTemplateDecl();
+  if (!EnableIfDecl || EnableIfTST->isIncompleteType())
+    return false;
+
+  // ... called "enable_if".
+  const IdentifierInfo *EnableIfII =
+    EnableIfDecl->getDeclName().getAsIdentifierInfo();
+  if (!EnableIfII || !EnableIfII->isStr("enable_if"))
+    return false;
+
+  // Assume the first template argument is the condition.
+  CondRange = EnableIfTSTLoc->getArgLoc(0).getSourceRange();
+  return true;
+}
+
 /// \brief Build the type that describes a C++ typename specifier,
 /// e.g., "typename T::type".
 QualType
@@ -6926,9 +7058,19 @@ Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
   unsigned DiagID = 0;
   Decl *Referenced = 0;
   switch (Result.getResultKind()) {
-  case LookupResult::NotFound:
+  case LookupResult::NotFound: {
+    // If we're looking up 'type' within a template named 'enable_if', produce
+    // a more specific diagnostic.
+    SourceRange CondRange;
+    if (isEnableIf(QualifierLoc, II, CondRange)) {
+      Diag(CondRange.getBegin(), diag::err_typename_nested_not_found_enable_if)
+        << Ctx << CondRange;
+      return QualType();
+    }
+
     DiagID = diag::err_typename_nested_not_found;
     break;
+  }
 
   case LookupResult::FoundUnresolvedValue: {
     // We found a using declaration that is a value. Most likely, the using