зеркало из https://github.com/microsoft/clang-1.git
For template argument deduction from class template partial
specializations, separate out the deduction part from the checking and substitution of the deduced arguments. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102600 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Douglas Gregor
Родитель
fc39dc4c78
Коммит
31dce8f606
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@ -961,6 +961,115 @@ static TemplateParameter makeTemplateParameter(Decl *D) {
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return TemplateParameter(cast<TemplateTemplateParmDecl>(D));
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}
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/// Complete template argument deduction for a class template partial
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/// specialization.
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static Sema::TemplateDeductionResult
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FinishTemplateArgumentDeduction(Sema &S,
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ClassTemplatePartialSpecializationDecl *Partial,
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const TemplateArgumentList &TemplateArgs,
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llvm::SmallVectorImpl<DeducedTemplateArgument> &Deduced,
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Sema::TemplateDeductionInfo &Info) {
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// Trap errors.
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Sema::SFINAETrap Trap(S);
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Sema::ContextRAII SavedContext(S, Partial);
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// C++ [temp.deduct.type]p2:
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// [...] or if any template argument remains neither deduced nor
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// explicitly specified, template argument deduction fails.
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TemplateArgumentListBuilder Builder(Partial->getTemplateParameters(),
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Deduced.size());
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for (unsigned I = 0, N = Deduced.size(); I != N; ++I) {
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if (Deduced[I].isNull()) {
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Decl *Param
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= const_cast<NamedDecl *>(
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Partial->getTemplateParameters()->getParam(I));
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Info.Param = makeTemplateParameter(Param);
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return Sema::TDK_Incomplete;
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}
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Builder.Append(Deduced[I]);
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}
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// Form the template argument list from the deduced template arguments.
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TemplateArgumentList *DeducedArgumentList
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= new (S.Context) TemplateArgumentList(S.Context, Builder,
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/*TakeArgs=*/true);
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Info.reset(DeducedArgumentList);
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// Substitute the deduced template arguments into the template
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// arguments of the class template partial specialization, and
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// verify that the instantiated template arguments are both valid
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// and are equivalent to the template arguments originally provided
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// to the class template.
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// FIXME: Do we have to correct the types of deduced non-type template
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// arguments (in particular, integral non-type template arguments?).
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Sema::LocalInstantiationScope InstScope(S);
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ClassTemplateDecl *ClassTemplate = Partial->getSpecializedTemplate();
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const TemplateArgumentLoc *PartialTemplateArgs
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= Partial->getTemplateArgsAsWritten();
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unsigned N = Partial->getNumTemplateArgsAsWritten();
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// Note that we don't provide the langle and rangle locations.
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TemplateArgumentListInfo InstArgs;
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for (unsigned I = 0; I != N; ++I) {
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Decl *Param = const_cast<NamedDecl *>(
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ClassTemplate->getTemplateParameters()->getParam(I));
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TemplateArgumentLoc InstArg;
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if (S.Subst(PartialTemplateArgs[I], InstArg,
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MultiLevelTemplateArgumentList(*DeducedArgumentList))) {
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Info.Param = makeTemplateParameter(Param);
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Info.FirstArg = PartialTemplateArgs[I].getArgument();
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return Sema::TDK_SubstitutionFailure;
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}
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InstArgs.addArgument(InstArg);
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}
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TemplateArgumentListBuilder ConvertedInstArgs(
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ClassTemplate->getTemplateParameters(), N);
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if (S.CheckTemplateArgumentList(ClassTemplate, Partial->getLocation(),
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InstArgs, false, ConvertedInstArgs)) {
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// FIXME: fail with more useful information?
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return Sema::TDK_SubstitutionFailure;
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}
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for (unsigned I = 0, E = ConvertedInstArgs.flatSize(); I != E; ++I) {
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TemplateArgument InstArg = ConvertedInstArgs.getFlatArguments()[I];
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Decl *Param = const_cast<NamedDecl *>(
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ClassTemplate->getTemplateParameters()->getParam(I));
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if (InstArg.getKind() == TemplateArgument::Expression) {
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// When the argument is an expression, check the expression result
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// against the actual template parameter to get down to the canonical
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// template argument.
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Expr *InstExpr = InstArg.getAsExpr();
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if (NonTypeTemplateParmDecl *NTTP
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= dyn_cast<NonTypeTemplateParmDecl>(Param)) {
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if (S.CheckTemplateArgument(NTTP, NTTP->getType(), InstExpr, InstArg)) {
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Info.Param = makeTemplateParameter(Param);
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Info.FirstArg = Partial->getTemplateArgs()[I];
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return Sema::TDK_SubstitutionFailure;
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}
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}
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}
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if (!isSameTemplateArg(S.Context, TemplateArgs[I], InstArg)) {
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Info.Param = makeTemplateParameter(Param);
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Info.FirstArg = TemplateArgs[I];
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Info.SecondArg = InstArg;
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return Sema::TDK_NonDeducedMismatch;
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}
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}
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if (Trap.hasErrorOccurred())
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return Sema::TDK_SubstitutionFailure;
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return Sema::TDK_Success;
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}
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/// \brief Perform template argument deduction to determine whether
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/// the given template arguments match the given class template
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/// partial specialization per C++ [temp.class.spec.match].
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@ -988,101 +1097,11 @@ Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
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if (Inst)
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return TDK_InstantiationDepth;
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ContextRAII SavedContext(*this, Partial);
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// C++ [temp.deduct.type]p2:
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// [...] or if any template argument remains neither deduced nor
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// explicitly specified, template argument deduction fails.
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TemplateArgumentListBuilder Builder(Partial->getTemplateParameters(),
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Deduced.size());
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for (unsigned I = 0, N = Deduced.size(); I != N; ++I) {
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if (Deduced[I].isNull()) {
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Decl *Param
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= const_cast<NamedDecl *>(
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Partial->getTemplateParameters()->getParam(I));
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Info.Param = makeTemplateParameter(Param);
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return TDK_Incomplete;
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}
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Builder.Append(Deduced[I]);
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}
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// Form the template argument list from the deduced template arguments.
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TemplateArgumentList *DeducedArgumentList
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= new (Context) TemplateArgumentList(Context, Builder, /*TakeArgs=*/true);
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Info.reset(DeducedArgumentList);
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// Substitute the deduced template arguments into the template
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// arguments of the class template partial specialization, and
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// verify that the instantiated template arguments are both valid
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// and are equivalent to the template arguments originally provided
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// to the class template.
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// FIXME: Do we have to correct the types of deduced non-type template
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// arguments (in particular, integral non-type template arguments?).
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Sema::LocalInstantiationScope InstScope(*this);
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ClassTemplateDecl *ClassTemplate = Partial->getSpecializedTemplate();
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const TemplateArgumentLoc *PartialTemplateArgs
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= Partial->getTemplateArgsAsWritten();
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unsigned N = Partial->getNumTemplateArgsAsWritten();
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// Note that we don't provide the langle and rangle locations.
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TemplateArgumentListInfo InstArgs;
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for (unsigned I = 0; I != N; ++I) {
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Decl *Param = const_cast<NamedDecl *>(
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ClassTemplate->getTemplateParameters()->getParam(I));
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TemplateArgumentLoc InstArg;
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if (Subst(PartialTemplateArgs[I], InstArg,
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MultiLevelTemplateArgumentList(*DeducedArgumentList))) {
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Info.Param = makeTemplateParameter(Param);
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Info.FirstArg = PartialTemplateArgs[I].getArgument();
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return TDK_SubstitutionFailure;
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}
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InstArgs.addArgument(InstArg);
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}
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TemplateArgumentListBuilder ConvertedInstArgs(
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ClassTemplate->getTemplateParameters(), N);
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if (CheckTemplateArgumentList(ClassTemplate, Partial->getLocation(),
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InstArgs, false, ConvertedInstArgs)) {
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// FIXME: fail with more useful information?
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return TDK_SubstitutionFailure;
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}
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for (unsigned I = 0, E = ConvertedInstArgs.flatSize(); I != E; ++I) {
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TemplateArgument InstArg = ConvertedInstArgs.getFlatArguments()[I];
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Decl *Param = const_cast<NamedDecl *>(
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ClassTemplate->getTemplateParameters()->getParam(I));
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if (InstArg.getKind() == TemplateArgument::Expression) {
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// When the argument is an expression, check the expression result
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// against the actual template parameter to get down to the canonical
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// template argument.
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Expr *InstExpr = InstArg.getAsExpr();
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if (NonTypeTemplateParmDecl *NTTP
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= dyn_cast<NonTypeTemplateParmDecl>(Param)) {
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if (CheckTemplateArgument(NTTP, NTTP->getType(), InstExpr, InstArg)) {
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Info.Param = makeTemplateParameter(Param);
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Info.FirstArg = Partial->getTemplateArgs()[I];
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return TDK_SubstitutionFailure;
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}
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}
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}
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if (!isSameTemplateArg(Context, TemplateArgs[I], InstArg)) {
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Info.Param = makeTemplateParameter(Param);
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Info.FirstArg = TemplateArgs[I];
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Info.SecondArg = InstArg;
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return TDK_NonDeducedMismatch;
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}
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}
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if (Trap.hasErrorOccurred())
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return TDK_SubstitutionFailure;
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return TDK_Success;
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return Sema::TDK_SubstitutionFailure;
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return ::FinishTemplateArgumentDeduction(*this, Partial, TemplateArgs,
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Deduced, Info);
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}
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/// \brief Determine whether the given type T is a simple-template-id type.
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@ -2341,12 +2360,15 @@ Sema::getMoreSpecializedPartialSpecialization(
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// whose type is a class template specialization with the template
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// arguments of the second partial specialization.
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//
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// Rather than synthesize function templates, we merely perform the
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// equivalent partial ordering by performing deduction directly on the
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// template arguments of the class template partial specializations. This
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// computation is slightly simpler than the general problem of function
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// template partial ordering, because class template partial specializations
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// are more constrained. We know that every template parameter is deduc
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// Rather than synthesize function templates, we merely perform the
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// equivalent partial ordering by performing deduction directly on
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// the template arguments of the class template partial
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// specializations. This computation is slightly simpler than the
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// general problem of function template partial ordering, because
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// class template partial specializations are more constrained. We
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// know that every template parameter is deducible from the class
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// template partial specialization's template arguments, for
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// example.
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llvm::SmallVector<DeducedTemplateArgument, 4> Deduced;
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Sema::TemplateDeductionInfo Info(Context, Loc);
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