Started implementing variable templates. Top level declarations should be fully supported, up to some limitations documented as FIXMEs or TODO. Static data member templates work very partially. Static data member templates of class templates need particular attention...
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187762 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 8d6aaa0..e873546 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -2246,7 +2246,7 @@
}
/// \brief Perform template argument deduction to determine whether
-/// the given template arguments match the given class template
+/// the given template arguments match the given variable template
/// partial specialization per C++ [temp.class.spec.match].
Sema::TemplateDeductionResult
Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
@@ -2287,6 +2287,160 @@
Deduced, Info);
}
+/// Complete template argument deduction for a variable template partial
+/// specialization.
+/// TODO: Unify with ClassTemplatePartialSpecializationDecl version.
+static Sema::TemplateDeductionResult FinishTemplateArgumentDeduction(
+ Sema &S, VarTemplatePartialSpecializationDecl *Partial,
+ const TemplateArgumentList &TemplateArgs,
+ SmallVectorImpl<DeducedTemplateArgument> &Deduced,
+ TemplateDeductionInfo &Info) {
+ // Unevaluated SFINAE context.
+ EnterExpressionEvaluationContext Unevaluated(S, Sema::Unevaluated);
+ Sema::SFINAETrap Trap(S);
+
+ // C++ [temp.deduct.type]p2:
+ // [...] or if any template argument remains neither deduced nor
+ // explicitly specified, template argument deduction fails.
+ SmallVector<TemplateArgument, 4> Builder;
+ TemplateParameterList *PartialParams = Partial->getTemplateParameters();
+ for (unsigned I = 0, N = PartialParams->size(); I != N; ++I) {
+ NamedDecl *Param = PartialParams->getParam(I);
+ if (Deduced[I].isNull()) {
+ Info.Param = makeTemplateParameter(Param);
+ return Sema::TDK_Incomplete;
+ }
+
+ // We have deduced this argument, so it still needs to be
+ // checked and converted.
+
+ // First, for a non-type template parameter type that is
+ // initialized by a declaration, we need the type of the
+ // corresponding non-type template parameter.
+ QualType NTTPType;
+ if (NonTypeTemplateParmDecl *NTTP =
+ dyn_cast<NonTypeTemplateParmDecl>(Param)) {
+ NTTPType = NTTP->getType();
+ if (NTTPType->isDependentType()) {
+ TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+ Builder.data(), Builder.size());
+ NTTPType =
+ S.SubstType(NTTPType, MultiLevelTemplateArgumentList(TemplateArgs),
+ NTTP->getLocation(), NTTP->getDeclName());
+ if (NTTPType.isNull()) {
+ Info.Param = makeTemplateParameter(Param);
+ // FIXME: These template arguments are temporary. Free them!
+ Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder.data(),
+ Builder.size()));
+ return Sema::TDK_SubstitutionFailure;
+ }
+ }
+ }
+
+ if (ConvertDeducedTemplateArgument(S, Param, Deduced[I], Partial, NTTPType,
+ 0, Info, false, Builder)) {
+ Info.Param = makeTemplateParameter(Param);
+ // FIXME: These template arguments are temporary. Free them!
+ Info.reset(TemplateArgumentList::CreateCopy(S.Context, Builder.data(),
+ Builder.size()));
+ return Sema::TDK_SubstitutionFailure;
+ }
+ }
+
+ // Form the template argument list from the deduced template arguments.
+ TemplateArgumentList *DeducedArgumentList = TemplateArgumentList::CreateCopy(
+ S.Context, Builder.data(), Builder.size());
+
+ Info.reset(DeducedArgumentList);
+
+ // Substitute the deduced template arguments into the template
+ // arguments of the class template partial specialization, and
+ // verify that the instantiated template arguments are both valid
+ // and are equivalent to the template arguments originally provided
+ // to the class template.
+ LocalInstantiationScope InstScope(S);
+ VarTemplateDecl *VarTemplate = Partial->getSpecializedTemplate();
+ const TemplateArgumentLoc *PartialTemplateArgs =
+ Partial->getTemplateArgsAsWritten();
+
+ // Note that we don't provide the langle and rangle locations.
+ TemplateArgumentListInfo InstArgs;
+
+ if (S.Subst(PartialTemplateArgs, Partial->getNumTemplateArgsAsWritten(),
+ InstArgs, MultiLevelTemplateArgumentList(*DeducedArgumentList))) {
+ unsigned ArgIdx = InstArgs.size(), ParamIdx = ArgIdx;
+ if (ParamIdx >= Partial->getTemplateParameters()->size())
+ ParamIdx = Partial->getTemplateParameters()->size() - 1;
+
+ Decl *Param = const_cast<NamedDecl *>(
+ Partial->getTemplateParameters()->getParam(ParamIdx));
+ Info.Param = makeTemplateParameter(Param);
+ Info.FirstArg = PartialTemplateArgs[ArgIdx].getArgument();
+ return Sema::TDK_SubstitutionFailure;
+ }
+ SmallVector<TemplateArgument, 4> ConvertedInstArgs;
+ if (S.CheckTemplateArgumentList(VarTemplate, Partial->getLocation(), InstArgs,
+ false, ConvertedInstArgs))
+ return Sema::TDK_SubstitutionFailure;
+
+ TemplateParameterList *TemplateParams = VarTemplate->getTemplateParameters();
+ for (unsigned I = 0, E = TemplateParams->size(); I != E; ++I) {
+ TemplateArgument InstArg = ConvertedInstArgs.data()[I];
+ if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg)) {
+ Info.Param = makeTemplateParameter(TemplateParams->getParam(I));
+ Info.FirstArg = TemplateArgs[I];
+ Info.SecondArg = InstArg;
+ return Sema::TDK_NonDeducedMismatch;
+ }
+ }
+
+ if (Trap.hasErrorOccurred())
+ return Sema::TDK_SubstitutionFailure;
+
+ return Sema::TDK_Success;
+}
+
+/// \brief Perform template argument deduction to determine whether
+/// the given template arguments match the given variable template
+/// partial specialization per C++ [temp.class.spec.match].
+/// TODO: Unify with ClassTemplatePartialSpecializationDecl version.
+Sema::TemplateDeductionResult
+Sema::DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial,
+ const TemplateArgumentList &TemplateArgs,
+ TemplateDeductionInfo &Info) {
+ if (Partial->isInvalidDecl())
+ return TDK_Invalid;
+
+ // C++ [temp.class.spec.match]p2:
+ // A partial specialization matches a given actual template
+ // argument list if the template arguments of the partial
+ // specialization can be deduced from the actual template argument
+ // list (14.8.2).
+
+ // Unevaluated SFINAE context.
+ EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
+ SFINAETrap Trap(*this);
+
+ SmallVector<DeducedTemplateArgument, 4> Deduced;
+ Deduced.resize(Partial->getTemplateParameters()->size());
+ if (TemplateDeductionResult Result = ::DeduceTemplateArguments(
+ *this, Partial->getTemplateParameters(), Partial->getTemplateArgs(),
+ TemplateArgs, Info, Deduced))
+ return Result;
+
+ SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(), Deduced.end());
+ InstantiatingTemplate Inst(*this, Partial->getLocation(), Partial,
+ DeducedArgs, Info);
+ if (Inst)
+ return TDK_InstantiationDepth;
+
+ if (Trap.hasErrorOccurred())
+ return Sema::TDK_SubstitutionFailure;
+
+ return ::FinishTemplateArgumentDeduction(*this, Partial, TemplateArgs,
+ Deduced, Info);
+}
+
/// \brief Determine whether the given type T is a simple-template-id type.
static bool isSimpleTemplateIdType(QualType T) {
if (const TemplateSpecializationType *Spec
@@ -4278,6 +4432,63 @@
/*RefParamComparisons=*/0);
if (Better1) {
SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(),Deduced.end());
+ InstantiatingTemplate Inst(*this, PS2->getLocation(), PS2, DeducedArgs,
+ Info);
+ Better1 = !::FinishTemplateArgumentDeduction(
+ *this, PS2, PS1->getTemplateArgs(), Deduced, Info);
+ }
+
+ // Determine whether PS2 is at least as specialized as PS1
+ Deduced.clear();
+ Deduced.resize(PS1->getTemplateParameters()->size());
+ bool Better2 = !DeduceTemplateArgumentsByTypeMatch(
+ *this, PS1->getTemplateParameters(), PT1, PT2, Info, Deduced, TDF_None,
+ /*PartialOrdering=*/true,
+ /*RefParamComparisons=*/0);
+ if (Better2) {
+ SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(),
+ Deduced.end());
+ InstantiatingTemplate Inst(*this, PS1->getLocation(), PS1, DeducedArgs,
+ Info);
+ Better2 = !::FinishTemplateArgumentDeduction(
+ *this, PS1, PS2->getTemplateArgs(), Deduced, Info);
+ }
+
+ if (Better1 == Better2)
+ return 0;
+
+ return Better1 ? PS1 : PS2;
+}
+
+/// TODO: Unify with ClassTemplatePartialSpecializationDecl version.
+VarTemplatePartialSpecializationDecl *
+Sema::getMoreSpecializedPartialSpecialization(
+ VarTemplatePartialSpecializationDecl *PS1,
+ VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc) {
+ SmallVector<DeducedTemplateArgument, 4> Deduced;
+ TemplateDeductionInfo Info(Loc);
+
+ assert(PS1->getSpecializedTemplate() == PS1->getSpecializedTemplate() &&
+ "the partial specializations being compared should specialize"
+ " the same template.");
+ TemplateName Name(PS1->getSpecializedTemplate());
+ TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
+ QualType PT1 = Context.getTemplateSpecializationType(
+ CanonTemplate, PS1->getTemplateArgs().data(),
+ PS1->getTemplateArgs().size());
+ QualType PT2 = Context.getTemplateSpecializationType(
+ CanonTemplate, PS2->getTemplateArgs().data(),
+ PS2->getTemplateArgs().size());
+
+ // Determine whether PS1 is at least as specialized as PS2
+ Deduced.resize(PS2->getTemplateParameters()->size());
+ bool Better1 = !DeduceTemplateArgumentsByTypeMatch(
+ *this, PS2->getTemplateParameters(), PT2, PT1, Info, Deduced, TDF_None,
+ /*PartialOrdering=*/true,
+ /*RefParamComparisons=*/0);
+ if (Better1) {
+ SmallVector<TemplateArgument, 4> DeducedArgs(Deduced.begin(),
+ Deduced.end());
InstantiatingTemplate Inst(*this, PS2->getLocation(), PS2,
DeducedArgs, Info);
Better1 = !::FinishTemplateArgumentDeduction(*this, PS2,