From: Douglas Gregor Date: Thu, 14 Jan 2010 17:47:39 +0000 (+0000) Subject: When qualified lookup into the current instantiation fails (because it X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9edad9b6184c730a73dc9241c043ea3bae54189f;p=clang When qualified lookup into the current instantiation fails (because it finds nothing), and the current instantiation has dependent base classes, treat the qualified lookup as if it referred to an unknown specialization. Fixes PR6031. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@93433 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/AST/DeclCXX.h b/include/clang/AST/DeclCXX.h index 02581c1241..336a895de8 100644 --- a/include/clang/AST/DeclCXX.h +++ b/include/clang/AST/DeclCXX.h @@ -393,6 +393,9 @@ public: return reverse_base_class_const_iterator(vbases_begin()); } + /// \brief Determine whether this class has any dependent base classes. + bool hasAnyDependentBases() const; + /// Iterator access to method members. The method iterator visits /// all method members of the class, including non-instance methods, /// special methods, etc. diff --git a/lib/AST/DeclCXX.cpp b/lib/AST/DeclCXX.cpp index b30d335918..1cce35c0b3 100644 --- a/lib/AST/DeclCXX.cpp +++ b/lib/AST/DeclCXX.cpp @@ -144,6 +144,19 @@ CXXRecordDecl::setBases(ASTContext &C, } } +/// Callback function for CXXRecordDecl::forallBases that acknowledges +/// that it saw a base class. +static bool SawBase(const CXXRecordDecl *, void *) { + return true; +} + +bool CXXRecordDecl::hasAnyDependentBases() const { + if (!isDependentContext()) + return false; + + return !forallBases(SawBase, 0); +} + bool CXXRecordDecl::hasConstCopyConstructor(ASTContext &Context) const { return getCopyConstructor(Context, Qualifiers::Const) != 0; } diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h index 8fc34880c1..44bf48915e 100644 --- a/lib/Sema/Sema.h +++ b/lib/Sema/Sema.h @@ -2032,6 +2032,7 @@ public: bool isDependentScopeSpecifier(const CXXScopeSpec &SS); CXXRecordDecl *getCurrentInstantiationOf(NestedNameSpecifier *NNS); bool isUnknownSpecialization(const CXXScopeSpec &SS); + bool isCurrentInstantiationWithDependentBases(const CXXScopeSpec &SS); /// ActOnCXXGlobalScopeSpecifier - Return the object that represents the /// global scope ('::'). diff --git a/lib/Sema/SemaCXXScopeSpec.cpp b/lib/Sema/SemaCXXScopeSpec.cpp index a8f118ebdd..8594583ec3 100644 --- a/lib/Sema/SemaCXXScopeSpec.cpp +++ b/lib/Sema/SemaCXXScopeSpec.cpp @@ -210,6 +210,28 @@ bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) { return getCurrentInstantiationOf(NNS) == 0; } +/// \brief Determine whether the given scope specifier refers to a +/// current instantiation that has any dependent base clases. +/// +/// This check is typically used when we've performed lookup into the +/// current instantiation of a template, but that lookup failed. When +/// there are dependent bases present, however, the lookup needs to be +/// delayed until template instantiation time. +bool Sema::isCurrentInstantiationWithDependentBases(const CXXScopeSpec &SS) { + if (!SS.isSet()) + return false; + + NestedNameSpecifier *NNS = (NestedNameSpecifier*)SS.getScopeRep(); + if (!NNS->isDependent()) + return false; + + CXXRecordDecl *CurrentInstantiation = getCurrentInstantiationOf(NNS); + if (!CurrentInstantiation) + return false; + + return CurrentInstantiation->hasAnyDependentBases(); +} + /// \brief If the given nested name specifier refers to the current /// instantiation, return the declaration that corresponds to that /// current instantiation (C++0x [temp.dep.type]p1). diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index 75fe7fd00f..c54745f552 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -4785,8 +4785,18 @@ Sema::DeclPtrTy Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, if (Previous.isAmbiguous()) return DeclPtrTy(); - // A tag 'foo::bar' must already exist. if (Previous.empty()) { + // Name lookup did not find anything. However, if the + // nested-name-specifier refers to the current instantiation, + // and that current instantiation has any dependent base + // classes, we might find something at instantiation time: treat + // this as a dependent elaborated-type-specifier. + if (isCurrentInstantiationWithDependentBases(SS)) { + IsDependent = true; + return DeclPtrTy(); + } + + // A tag 'foo::bar' must already exist. Diag(NameLoc, diag::err_not_tag_in_scope) << Name << SS.getRange(); Name = 0; Invalid = true; diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp index e75277e823..d2e70cf9ad 100644 --- a/lib/Sema/SemaTemplate.cpp +++ b/lib/Sema/SemaTemplate.cpp @@ -1608,15 +1608,19 @@ Sema::ActOnDependentTemplateName(SourceLocation TemplateKWLoc, TemplateTy Template; TemplateNameKind TNK = isTemplateName(0, SS, Name, ObjectType, EnteringContext, Template); - if (TNK == TNK_Non_template) { + if (TNK == TNK_Non_template && + isCurrentInstantiationWithDependentBases(SS)) { + // This is a dependent template. + } else if (TNK == TNK_Non_template) { Diag(Name.getSourceRange().getBegin(), diag::err_template_kw_refers_to_non_template) << GetNameFromUnqualifiedId(Name) << Name.getSourceRange(); return TemplateTy(); + } else { + // We found something; return it. + return Template; } - - return Template; } NestedNameSpecifier *Qualifier @@ -4765,6 +4769,14 @@ Sema::CheckTypenameType(NestedNameSpecifier *NNS, const IdentifierInfo &II, Decl *Referenced = 0; switch (Result.getResultKind()) { case LookupResult::NotFound: + if (CurrentInstantiation && CurrentInstantiation->hasAnyDependentBases()) { + // We performed a lookup in the current instantiation and didn't + // find anything. However, this current instantiation has + // dependent bases, so we might be able to find something at + // instantiation time: just build a TypenameType and move on. + return Context.getTypenameType(NNS, &II); + } + DiagID = diag::err_typename_nested_not_found; break; diff --git a/test/SemaTemplate/dependent-base-classes.cpp b/test/SemaTemplate/dependent-base-classes.cpp index 242765894f..b9666dba61 100644 --- a/test/SemaTemplate/dependent-base-classes.cpp +++ b/test/SemaTemplate/dependent-base-classes.cpp @@ -10,3 +10,56 @@ struct X1 : T::apply { }; // expected-error{{missing 'template' keyword prior template struct X2 : vector { }; // expected-error{{unknown template name 'vector'}} + +namespace PR6031 { + template + struct A; + + template + struct C { }; + + template + struct II { + typedef typename A::type type; + }; + + template + struct FI : II + { + C a; + }; + + template + struct FI2 + { + C a; // expected-error{{no type named 'type' in 'struct PR6031::FI2'}} \ + // expected-error{{C++ requires a type specifier for all declarations}} + }; + + template + struct Base { + class Nested { }; + template struct MemberTemplate { }; + int a; + }; + + template + struct HasDepBase : Base { + int foo() { + class HasDepBase::Nested nested; + typedef typename HasDepBase::template MemberTemplate::type type; + return HasDepBase::a; + } + }; + + template + struct NoDepBase { + int foo() { + class NoDepBase::Nested nested; // expected-error{{'Nested' does not name a tag member in the specified scope}} + typedef typename NoDepBase::template MemberTemplate::type type; // expected-error{{'MemberTemplate' following the 'template' keyword does not refer to a template}} \ + // FIXME: expected-error{{expected an identifier or template-id after '::'}} \ + // FIXME: expected-error{{unqualified-id}} + return NoDepBase::a; // expected-error{{no member named 'a' in 'struct PR6031::NoDepBase'}} + } + }; +}