Rework when and how vtables are emitted, by tracking where vtables are
"used" (e.g., we will refer to the vtable in the generated code) and
when they are defined (i.e., because we've seen the key function
definition). Previously, we were effectively tracking "potential
definitions" rather than uses, so we were a bit too eager about emitting
vtables for classes without key functions.
The new scheme:
- For every use of a vtable, Sema calls MarkVTableUsed() to indicate
the use. For example, this occurs when calling a virtual member
function of the class, defining a constructor of that class type,
dynamic_cast'ing from that type to a derived class, casting
to/through a virtual base class, etc.
- For every definition of a vtable, Sema calls MarkVTableUsed() to
indicate the definition. This happens at the end of the translation
unit for classes whose key function has been defined (so we can
delay computation of the key function; see PR6564), and will also
occur with explicit template instantiation definitions.
- For every vtable defined/used, we mark all of the virtual member
functions of that vtable as defined/used, unless we know that the key
function is in another translation unit. This instantiates virtual
member functions when needed.
- At the end of the translation unit, Sema tells CodeGen (via the
ASTConsumer) which vtables must be defined (CodeGen will define
them) and which may be used (for which CodeGen will define the
vtables lazily).
From a language perspective, both the old and the new schemes are
permissible: we're allowed to instantiate virtual member functions
whenever we want per the standard. However, all other C++ compilers
were more lazy than we were, and our eagerness was both a performance
issue (we instantiated too much) and a portability problem (we broke
Boost test cases, which now pass).
Notes:
(1) There's a ton of churn in the tests, because the order in which
vtables get emitted to IR has changed. I've tried to isolate some of
the larger tests from these issues.
(2) Some diagnostics related to
implicitly-instantiated/implicitly-defined virtual member functions
have moved to the point of first use/definition. It's better this
way.
(3) I could use a review of the places where we MarkVTableUsed, to
see if I missed any place where the language effectively requires a
vtable.
Fixes PR7114 and PR6564.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103718 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 91effa4..569de32 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -164,6 +164,18 @@
}
}
+ // If this is a derived-to-base cast to a through a virtual base, we
+ // need a vtable.
+ if (Kind == CastExpr::CK_DerivedToBase &&
+ BasePathInvolvesVirtualBase(BasePath)) {
+ QualType T = Expr->getType();
+ if (const PointerType *Pointer = T->getAs<PointerType>())
+ T = Pointer->getPointeeType();
+ if (const RecordType *RecordTy = T->getAs<RecordType>())
+ MarkVTableUsed(Expr->getLocStart(),
+ cast<CXXRecordDecl>(RecordTy->getDecl()));
+ }
+
if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) {
if (ImpCast->getCastKind() == Kind && BasePath.empty()) {
ImpCast->setType(Ty);
@@ -199,10 +211,10 @@
// template instantiations earlier.
PerformPendingImplicitInstantiations();
- /// If ProcessPendingClassesWithUnmarkedVirtualMembers ends up marking
- /// any virtual member functions it might lead to more pending template
+ /// If DefinedUsedVTables ends up marking any virtual member
+ /// functions it might lead to more pending template
/// instantiations, which is why we need to loop here.
- if (!ProcessPendingClassesWithUnmarkedVirtualMembers())
+ if (!DefineUsedVTables())
break;
}
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 9d811a4..4ef5ebe 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -2560,27 +2560,38 @@
void MarkBaseAndMemberDestructorsReferenced(SourceLocation Loc,
CXXRecordDecl *Record);
- /// ClassesWithUnmarkedVirtualMembers - Contains record decls whose virtual
- /// members need to be marked as referenced at the end of the translation
- /// unit. It will contain polymorphic classes that do not have a key
- /// function or have a key function that has been defined.
- llvm::SmallVector<std::pair<CXXRecordDecl *, SourceLocation>, 4>
- ClassesWithUnmarkedVirtualMembers;
+ /// \brief The list of classes whose vtables have been used within
+ /// this translation unit, and the source locations at which the
+ /// first use occurred.
+ llvm::SmallVector<std::pair<CXXRecordDecl *, SourceLocation>, 16>
+ VTableUses;
- /// MaybeMarkVirtualMembersReferenced - If the passed in method is the
- /// key function of the record decl, will mark virtual member functions as
- /// referenced.
- void MaybeMarkVirtualMembersReferenced(SourceLocation Loc, CXXMethodDecl *MD);
+ /// \brief The set of classes whose vtables have been used within
+ /// this translation unit, and a bit that will be true if the vtable is
+ /// required to be emitted (otherwise, it should be emitted only if needed
+ /// by code generation).
+ llvm::DenseMap<CXXRecordDecl *, bool> VTablesUsed;
+
+ /// \brief A list of all of the dynamic classes in this translation
+ /// unit.
+ llvm::SmallVector<CXXRecordDecl *, 16> DynamicClasses;
+
+ /// \brief Note that the vtable for the given class was used at the
+ /// given location.
+ void MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
+ bool DefinitionRequired = false);
/// MarkVirtualMembersReferenced - Will mark all virtual members of the given
/// CXXRecordDecl referenced.
void MarkVirtualMembersReferenced(SourceLocation Loc,
const CXXRecordDecl *RD);
- /// ProcessPendingClassesWithUnmarkedVirtualMembers - Will process classes
- /// that might need to have their virtual members marked as referenced.
- /// Returns false if no work was done.
- bool ProcessPendingClassesWithUnmarkedVirtualMembers();
+ /// \brief Define all of the vtables that have been used in this
+ /// translation unit and reference any virtual members used by those
+ /// vtables.
+ ///
+ /// \returns true if any work was done, false otherwise.
+ bool DefineUsedVTables();
void AddImplicitlyDeclaredMembersToClass(Scope *S, CXXRecordDecl *ClassDecl);
@@ -2664,6 +2675,8 @@
void BuildBasePathArray(const CXXBasePaths &Paths,
CXXBaseSpecifierArray &BasePath);
+ bool BasePathInvolvesVirtualBase(const CXXBaseSpecifierArray &BasePath);
+
bool CheckDerivedToBaseConversion(QualType Derived, QualType Base,
SourceLocation Loc, SourceRange Range,
CXXBaseSpecifierArray *BasePath = 0,
diff --git a/lib/Sema/SemaCXXCast.cpp b/lib/Sema/SemaCXXCast.cpp
index 9f8b344..1dbdd06 100644
--- a/lib/Sema/SemaCXXCast.cpp
+++ b/lib/Sema/SemaCXXCast.cpp
@@ -388,6 +388,12 @@
return;
Kind = CastExpr::CK_DerivedToBase;
+
+ // If we are casting to or through a virtual base class, we need a
+ // vtable.
+ if (Self.BasePathInvolvesVirtualBase(BasePath))
+ Self.MarkVTableUsed(OpRange.getBegin(),
+ cast<CXXRecordDecl>(SrcRecord->getDecl()));
return;
}
@@ -398,6 +404,8 @@
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_polymorphic)
<< SrcPointee.getUnqualifiedType() << SrcExpr->getSourceRange();
}
+ Self.MarkVTableUsed(OpRange.getBegin(),
+ cast<CXXRecordDecl>(SrcRecord->getDecl()));
// Done. Everything else is run-time checks.
Kind = CastExpr::CK_Dynamic;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index b4f5d13..76334e9 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -4575,12 +4575,14 @@
WP.disableCheckFallThrough();
}
- if (!FD->isInvalidDecl())
+ if (!FD->isInvalidDecl()) {
DiagnoseUnusedParameters(FD->param_begin(), FD->param_end());
-
- if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD))
- MaybeMarkVirtualMembersReferenced(Method->getLocation(), Method);
-
+
+ // If this is a constructor, we need a vtable.
+ if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(FD))
+ MarkVTableUsed(FD->getLocation(), Constructor->getParent());
+ }
+
assert(FD == getCurFunctionDecl() && "Function parsing confused");
} else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
assert(MD == getCurMethodDecl() && "Method parsing confused");
@@ -5447,37 +5449,6 @@
"Broken injected-class-name");
}
-// Traverses the class and any nested classes, making a note of any
-// dynamic classes that have no key function so that we can mark all of
-// their virtual member functions as "used" at the end of the translation
-// unit. This ensures that all functions needed by the vtable will get
-// instantiated/synthesized.
-static void
-RecordDynamicClassesWithNoKeyFunction(Sema &S, CXXRecordDecl *Record,
- SourceLocation Loc) {
- // We don't look at dependent or undefined classes.
- if (Record->isDependentContext() || !Record->isDefinition())
- return;
-
- if (Record->isDynamicClass()) {
- const CXXMethodDecl *KeyFunction = S.Context.getKeyFunction(Record);
-
- if (!KeyFunction)
- S.ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(Record,
- Loc));
-
- if ((!KeyFunction || (KeyFunction->getBody() && KeyFunction->isInlined()))
- && Record->getLinkage() == ExternalLinkage)
- S.Diag(Record->getLocation(), diag::warn_weak_vtable) << Record;
- }
- for (DeclContext::decl_iterator D = Record->decls_begin(),
- DEnd = Record->decls_end();
- D != DEnd; ++D) {
- if (CXXRecordDecl *Nested = dyn_cast<CXXRecordDecl>(*D))
- RecordDynamicClassesWithNoKeyFunction(S, Nested, Loc);
- }
-}
-
void Sema::ActOnTagFinishDefinition(Scope *S, DeclPtrTy TagD,
SourceLocation RBraceLoc) {
AdjustDeclIfTemplate(TagD);
@@ -5489,10 +5460,6 @@
// Exit this scope of this tag's definition.
PopDeclContext();
-
- if (isa<CXXRecordDecl>(Tag) && !Tag->getLexicalDeclContext()->isRecord())
- RecordDynamicClassesWithNoKeyFunction(*this, cast<CXXRecordDecl>(Tag),
- RBraceLoc);
// Notify the consumer that we've defined a tag.
Consumer.HandleTagDeclDefinition(Tag);
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 7f8d245..558746b 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -735,6 +735,18 @@
BasePathArray.push_back(Path[I].Base);
}
+/// \brief Determine whether the given base path includes a virtual
+/// base class.
+bool Sema::BasePathInvolvesVirtualBase(const CXXBaseSpecifierArray &BasePath) {
+ for (CXXBaseSpecifierArray::iterator B = BasePath.begin(),
+ BEnd = BasePath.end();
+ B != BEnd; ++B)
+ if ((*B)->isVirtual())
+ return true;
+
+ return false;
+}
+
/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
/// conversion (where Derived and Base are class types) is
/// well-formed, meaning that the conversion is unambiguous (and
@@ -2466,6 +2478,9 @@
}
}
}
+
+ if (Record->isDynamicClass())
+ DynamicClasses.push_back(Record);
}
void Sema::ActOnFinishCXXMemberSpecification(Scope* S, SourceLocation RLoc,
@@ -4154,7 +4169,7 @@
Constructor->setInvalidDecl();
} else {
Constructor->setUsed();
- MaybeMarkVirtualMembersReferenced(CurrentLocation, Constructor);
+ MarkVTableUsed(CurrentLocation, ClassDecl);
}
}
@@ -4183,7 +4198,7 @@
}
Destructor->setUsed();
- MaybeMarkVirtualMembersReferenced(CurrentLocation, Destructor);
+ MarkVTableUsed(CurrentLocation, ClassDecl);
}
/// \brief Builds a statement that copies the given entity from \p From to
@@ -4641,8 +4656,6 @@
/*isStmtExpr=*/false);
assert(!Body.isInvalid() && "Compound statement creation cannot fail");
CopyAssignOperator->setBody(Body.takeAs<Stmt>());
-
- MaybeMarkVirtualMembersReferenced(CurrentLocation, CopyAssignOperator);
}
void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
@@ -4670,7 +4683,6 @@
MultiStmtArg(*this, 0, 0),
/*isStmtExpr=*/false)
.takeAs<Stmt>());
- MaybeMarkVirtualMembersReferenced(CurrentLocation, CopyConstructor);
}
CopyConstructor->setUsed();
@@ -6019,90 +6031,120 @@
return Dcl;
}
-static bool needsVTable(CXXMethodDecl *MD, ASTContext &Context) {
- // Ignore dependent types.
- if (MD->isDependentContext())
- return false;
-
- // Ignore declarations that are not definitions.
- if (!MD->isThisDeclarationADefinition())
- return false;
-
- CXXRecordDecl *RD = MD->getParent();
-
- // Ignore classes without a vtable.
- if (!RD->isDynamicClass())
- return false;
-
- switch (MD->getParent()->getTemplateSpecializationKind()) {
- case TSK_Undeclared:
- case TSK_ExplicitSpecialization:
- // Classes that aren't instantiations of templates don't need their
- // virtual methods marked until we see the definition of the key
- // function.
- break;
-
- case TSK_ImplicitInstantiation:
- // This is a constructor of a class template; mark all of the virtual
- // members as referenced to ensure that they get instantiatied.
- if (isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD))
- return true;
- break;
-
- case TSK_ExplicitInstantiationDeclaration:
- return false;
-
- case TSK_ExplicitInstantiationDefinition:
- // This is method of a explicit instantiation; mark all of the virtual
- // members as referenced to ensure that they get instantiatied.
- return true;
- }
-
- // Consider only out-of-line definitions of member functions. When we see
- // an inline definition, it's too early to compute the key function.
- if (!MD->isOutOfLine())
- return false;
-
- const CXXMethodDecl *KeyFunction = Context.getKeyFunction(RD);
-
- // If there is no key function, we will need a copy of the vtable.
- if (!KeyFunction)
- return true;
-
- // If this is the key function, we need to mark virtual members.
- if (KeyFunction->getCanonicalDecl() == MD->getCanonicalDecl())
- return true;
-
- return false;
-}
-
-void Sema::MaybeMarkVirtualMembersReferenced(SourceLocation Loc,
- CXXMethodDecl *MD) {
- CXXRecordDecl *RD = MD->getParent();
-
- // We will need to mark all of the virtual members as referenced to build the
- // vtable.
- if (!needsVTable(MD, Context))
+void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
+ bool DefinitionRequired) {
+ // Ignore any vtable uses in unevaluated operands or for classes that do
+ // not have a vtable.
+ if (!Class->isDynamicClass() || Class->isDependentContext() ||
+ CurContext->isDependentContext() ||
+ ExprEvalContexts.back().Context == Unevaluated)
return;
- TemplateSpecializationKind kind = RD->getTemplateSpecializationKind();
- if (kind == TSK_ImplicitInstantiation)
- ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(RD, Loc));
+ // Try to insert this class into the map.
+ Class = cast<CXXRecordDecl>(Class->getCanonicalDecl());
+ std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
+ Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
+ if (!Pos.second) {
+ Pos.first->second = Pos.first->second || DefinitionRequired;
+ return;
+ }
+
+ // Local classes need to have their virtual members marked
+ // immediately. For all other classes, we mark their virtual members
+ // at the end of the translation unit.
+ if (Class->isLocalClass())
+ MarkVirtualMembersReferenced(Loc, Class);
else
- MarkVirtualMembersReferenced(Loc, RD);
+ VTableUses.push_back(std::make_pair(Class, Loc));
}
-bool Sema::ProcessPendingClassesWithUnmarkedVirtualMembers() {
- if (ClassesWithUnmarkedVirtualMembers.empty())
+bool Sema::DefineUsedVTables() {
+ // If any dynamic classes have their key function defined within
+ // this translation unit, then those vtables are considered "used" and must
+ // be emitted.
+ for (unsigned I = 0, N = DynamicClasses.size(); I != N; ++I) {
+ if (const CXXMethodDecl *KeyFunction
+ = Context.getKeyFunction(DynamicClasses[I])) {
+ const FunctionDecl *Definition = 0;
+ if (KeyFunction->getBody(Definition) && !Definition->isInlined() &&
+ !Definition->isImplicit())
+ MarkVTableUsed(Definition->getLocation(), DynamicClasses[I], true);
+ }
+ }
+
+ if (VTableUses.empty())
return false;
- while (!ClassesWithUnmarkedVirtualMembers.empty()) {
- CXXRecordDecl *RD = ClassesWithUnmarkedVirtualMembers.back().first;
- SourceLocation Loc = ClassesWithUnmarkedVirtualMembers.back().second;
- ClassesWithUnmarkedVirtualMembers.pop_back();
- MarkVirtualMembersReferenced(Loc, RD);
+ // Note: The VTableUses vector could grow as a result of marking
+ // the members of a class as "used", so we check the size each
+ // time through the loop and prefer indices (with are stable) to
+ // iterators (which are not).
+ for (unsigned I = 0; I != VTableUses.size(); ++I) {
+ CXXRecordDecl *Class
+ = cast_or_null<CXXRecordDecl>(VTableUses[I].first)->getDefinition();
+ if (!Class)
+ continue;
+
+ SourceLocation Loc = VTableUses[I].second;
+
+ // If this class has a key function, but that key function is
+ // defined in another translation unit, we don't need to emit the
+ // vtable even though we're using it.
+ const CXXMethodDecl *KeyFunction = Context.getKeyFunction(Class);
+ if (KeyFunction && !KeyFunction->getBody()) {
+ switch (KeyFunction->getTemplateSpecializationKind()) {
+ case TSK_Undeclared:
+ case TSK_ExplicitSpecialization:
+ case TSK_ExplicitInstantiationDeclaration:
+ // The key function is in another translation unit.
+ continue;
+
+ case TSK_ExplicitInstantiationDefinition:
+ case TSK_ImplicitInstantiation:
+ // We will be instantiating the key function.
+ break;
+ }
+ } else if (!KeyFunction) {
+ // If we have a class with no key function that is the subject
+ // of an explicit instantiation declaration, suppress the
+ // vtable; it will live with the explicit instantiation
+ // definition.
+ bool IsExplicitInstantiationDeclaration
+ = Class->getTemplateSpecializationKind()
+ == TSK_ExplicitInstantiationDeclaration;
+ for (TagDecl::redecl_iterator R = Class->redecls_begin(),
+ REnd = Class->redecls_end();
+ R != REnd; ++R) {
+ TemplateSpecializationKind TSK
+ = cast<CXXRecordDecl>(*R)->getTemplateSpecializationKind();
+ if (TSK == TSK_ExplicitInstantiationDeclaration)
+ IsExplicitInstantiationDeclaration = true;
+ else if (TSK == TSK_ExplicitInstantiationDefinition) {
+ IsExplicitInstantiationDeclaration = false;
+ break;
+ }
+ }
+
+ if (IsExplicitInstantiationDeclaration)
+ continue;
+ }
+
+ // Mark all of the virtual members of this class as referenced, so
+ // that we can build a vtable. Then, tell the AST consumer that a
+ // vtable for this class is required.
+ MarkVirtualMembersReferenced(Loc, Class);
+ CXXRecordDecl *Canonical = cast<CXXRecordDecl>(Class->getCanonicalDecl());
+ Consumer.HandleVTable(Class, VTablesUsed[Canonical]);
+
+ // Optionally warn if we're emitting a weak vtable.
+ if (Class->getLinkage() == ExternalLinkage &&
+ Class->getTemplateSpecializationKind() != TSK_ImplicitInstantiation) {
+ if (!KeyFunction || (KeyFunction->getBody() && KeyFunction->isInlined()))
+ Diag(Class->getLocation(), diag::warn_weak_vtable) << Class;
+ }
}
-
+ VTableUses.clear();
+
return true;
}
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 73493b6..13f44b9 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -7503,17 +7503,19 @@
DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals);
}
- MaybeMarkVirtualMembersReferenced(Loc, Constructor);
+ MarkVTableUsed(Loc, Constructor->getParent());
} else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
if (Destructor->isImplicit() && !Destructor->isUsed())
DefineImplicitDestructor(Loc, Destructor);
-
+ if (Destructor->isVirtual())
+ MarkVTableUsed(Loc, Destructor->getParent());
} else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) {
if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() &&
MethodDecl->getOverloadedOperator() == OO_Equal) {
if (!MethodDecl->isUsed())
DefineImplicitCopyAssignment(Loc, MethodDecl);
- }
+ } else if (MethodDecl->isVirtual())
+ MarkVTableUsed(Loc, MethodDecl->getParent());
}
if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
// Implicit instantiation of function templates and member functions of
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 8b17f84..15c2100 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -314,8 +314,12 @@
// When typeid is applied to an expression other than an lvalue of a
// polymorphic class type [...] [the] expression is an unevaluated
// operand. [...]
- if (RecordD->isPolymorphic() && E->isLvalue(Context) == Expr::LV_Valid)
+ if (RecordD->isPolymorphic() && E->isLvalue(Context) == Expr::LV_Valid) {
isUnevaluatedOperand = false;
+
+ // We require a vtable to query the type at run time.
+ MarkVTableUsed(TypeidLoc, RecordD);
+ }
}
// C++ [expr.typeid]p4:
@@ -445,6 +449,12 @@
if (Res.isInvalid())
return true;
E = Res.takeAs<Expr>();
+
+ // If we are throwing a polymorphic class type or pointer thereof,
+ // exception handling will make use of the vtable.
+ if (const RecordType *RecordTy = Ty->getAs<RecordType>())
+ MarkVTableUsed(ThrowLoc, cast<CXXRecordDecl>(RecordTy->getDecl()));
+
return false;
}
@@ -1802,17 +1812,24 @@
break;
}
- case ICK_Derived_To_Base:
+ case ICK_Derived_To_Base: {
+ CXXBaseSpecifierArray BasePath;
if (CheckDerivedToBaseConversion(From->getType(),
ToType.getNonReferenceType(),
From->getLocStart(),
- From->getSourceRange(), 0,
+ From->getSourceRange(),
+ &BasePath,
IgnoreBaseAccess))
return true;
+
ImpCastExprToType(From, ToType.getNonReferenceType(),
- CastExpr::CK_DerivedToBase);
+ CastExpr::CK_DerivedToBase,
+ /*isLvalue=*/(From->getType()->isRecordType() &&
+ From->isLvalue(Context) == Expr::LV_Valid),
+ BasePath);
break;
-
+ }
+
default:
assert(false && "Improper second standard conversion");
break;
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index fea7e61..851fb9e 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -3540,6 +3540,15 @@
&BasePath, IgnoreBaseAccess))
return S.ExprError();
+ if (S.BasePathInvolvesVirtualBase(BasePath)) {
+ QualType T = SourceType;
+ if (const PointerType *Pointer = T->getAs<PointerType>())
+ T = Pointer->getPointeeType();
+ if (const RecordType *RecordTy = T->getAs<RecordType>())
+ S.MarkVTableUsed(CurInitExpr->getLocStart(),
+ cast<CXXRecordDecl>(RecordTy->getDecl()));
+ }
+
CurInit = S.Owned(new (S.Context) ImplicitCastExpr(Step->Type,
CastExpr::CK_DerivedToBase,
(Expr*)CurInit.release(),
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 0f3f86d..9009b4d 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -4597,7 +4597,6 @@
}
// Explicit instantiation of a class template specialization
-// FIXME: Implement extern template semantics
Sema::DeclResult
Sema::ActOnExplicitInstantiation(Scope *S,
SourceLocation ExternLoc,
@@ -4760,7 +4759,9 @@
Specialization->getDefinition());
if (!Def)
InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
-
+ else if (TSK == TSK_ExplicitInstantiationDefinition)
+ MarkVTableUsed(TemplateNameLoc, Specialization, true);
+
// Instantiate the members of this class template specialization.
Def = cast_or_null<ClassTemplateSpecializationDecl>(
Specialization->getDefinition());
@@ -4895,6 +4896,9 @@
InstantiateClassMembers(NameLoc, RecordDef,
getTemplateInstantiationArgs(Record), TSK);
+ if (TSK == TSK_ExplicitInstantiationDefinition)
+ MarkVTableUsed(NameLoc, RecordDef, true);
+
// FIXME: We don't have any representation for explicit instantiations of
// member classes. Such a representation is not needed for compilation, but it
// should be available for clients that want to see all of the declarations in
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 589b995..0e4dfcb 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -1221,25 +1221,15 @@
// Exit the scope of this instantiation.
SavedContext.pop();
- // If this is a polymorphic C++ class without a key function, we'll
- // have to mark all of the virtual members to allow emission of a vtable
- // in this translation unit.
- if (Instantiation->isDynamicClass() &&
- !Context.getKeyFunction(Instantiation)) {
- // Local classes need to have their methods instantiated immediately in
- // order to have the correct instantiation scope.
- if (Instantiation->isLocalClass()) {
- MarkVirtualMembersReferenced(PointOfInstantiation,
- Instantiation);
- } else {
- ClassesWithUnmarkedVirtualMembers.push_back(std::make_pair(Instantiation,
- PointOfInstantiation));
- }
- }
-
- if (!Invalid)
+ if (!Invalid) {
Consumer.HandleTagDeclDefinition(Instantiation);
+ // Always emit the vtable for an explicit instantiation definition
+ // of a polymorphic class template specialization.
+ if (TSK == TSK_ExplicitInstantiationDefinition)
+ MarkVTableUsed(PointOfInstantiation, Instantiation, true);
+ }
+
return Invalid;
}
@@ -1263,6 +1253,12 @@
// declaration (C++0x [temp.explicit]p10); go ahead and perform the
// explicit instantiation.
ClassTemplateSpec->setSpecializationKind(TSK);
+
+ // If this is an explicit instantiation definition, mark the
+ // vtable as used.
+ if (TSK == TSK_ExplicitInstantiationDefinition)
+ MarkVTableUsed(PointOfInstantiation, ClassTemplateSpec, true);
+
return false;
}