Author: Matheus Izvekov Date: 2025-01-28T17:25:05-03:00 New Revision: b1972689a43175451f27098b8fd6f58cf7275229
URL: https://github.com/llvm/llvm-project/commit/b1972689a43175451f27098b8fd6f58cf7275229 DIFF: https://github.com/llvm/llvm-project/commit/b1972689a43175451f27098b8fd6f58cf7275229.diff LOG: [clang] fix template argument conversion (#124386) Converted template arguments need to be converted again, if the corresponding template parameter changed, as different conversions might apply in that case. Added: Modified: clang/docs/ReleaseNotes.rst clang/include/clang/Sema/Sema.h clang/lib/Sema/SemaTemplate.cpp clang/lib/Sema/TreeTransform.h clang/test/SemaTemplate/cwg2398.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 6a11ed8513f811..c1bf2dc1c33aad 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -1034,6 +1034,9 @@ Bug Fixes to C++ Support - Fix immediate escalation not propagating through inherited constructors. (#GH112677) - Fixed assertions or false compiler diagnostics in the case of C++ modules for lambda functions or inline friend functions defined inside templates (#GH122493). +- Fix template argument checking so that converted template arguments are + converted again. This fixes some issues with partial ordering involving + template template parameters with non-type template parameters. - Clang now rejects declaring an alias template with the same name as its template parameter. (#GH123423) - Fixed the rejection of valid code when referencing an enumerator of an unscoped enum member with a prior declaration. (#GH124405) - Fixed immediate escalation of non-dependent expressions. (#GH123405) diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index 67fd7e396f1277..8a6dd4f6820bc7 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/include/clang/Sema/Sema.h @@ -11780,6 +11780,9 @@ class Sema final : public SemaBase { /// declaration and the type of its corresponding non-type template /// parameter, produce an expression that properly refers to that /// declaration. + /// FIXME: This is used in some contexts where the resulting expression + /// doesn't need to live too long. It would be useful if this function + /// could return a temporary expression. ExprResult BuildExpressionFromDeclTemplateArgument( const TemplateArgument &Arg, QualType ParamType, SourceLocation Loc, NamedDecl *TemplateParam = nullptr); diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 210df2836eeb07..cb9d78734e6bbf 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -5199,7 +5199,7 @@ convertTypeTemplateArgumentToTemplate(ASTContext &Context, TypeLoc TLoc) { } bool Sema::CheckTemplateArgument( - NamedDecl *Param, TemplateArgumentLoc &Arg, NamedDecl *Template, + NamedDecl *Param, TemplateArgumentLoc &ArgLoc, NamedDecl *Template, SourceLocation TemplateLoc, SourceLocation RAngleLoc, unsigned ArgumentPackIndex, SmallVectorImpl<TemplateArgument> &SugaredConverted, @@ -5208,9 +5208,10 @@ bool Sema::CheckTemplateArgument( bool PartialOrderingTTP, bool *MatchedPackOnParmToNonPackOnArg) { // Check template type parameters. if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) - return CheckTemplateTypeArgument(TTP, Arg, SugaredConverted, + return CheckTemplateTypeArgument(TTP, ArgLoc, SugaredConverted, CanonicalConverted); + const TemplateArgument &Arg = ArgLoc.getArgument(); // Check non-type template parameters. if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) { // Do substitution on the type of the non-type template parameter @@ -5252,63 +5253,73 @@ bool Sema::CheckTemplateArgument( return true; } - switch (Arg.getArgument().getKind()) { - case TemplateArgument::Null: - llvm_unreachable("Should never see a NULL template argument here"); - - case TemplateArgument::Expression: { - Expr *E = Arg.getArgument().getAsExpr(); + auto checkExpr = [&](Expr *E) -> Expr * { TemplateArgument SugaredResult, CanonicalResult; unsigned CurSFINAEErrors = NumSFINAEErrors; ExprResult Res = CheckTemplateArgument(NTTP, NTTPType, E, SugaredResult, CanonicalResult, PartialOrderingTTP, CTAK); - if (Res.isInvalid()) - return true; // If the current template argument causes an error, give up now. - if (CurSFINAEErrors < NumSFINAEErrors) - return true; + if (Res.isInvalid() || CurSFINAEErrors < NumSFINAEErrors) + return nullptr; + SugaredConverted.push_back(SugaredResult); + CanonicalConverted.push_back(CanonicalResult); + return Res.get(); + }; + + switch (Arg.getKind()) { + case TemplateArgument::Null: + llvm_unreachable("Should never see a NULL template argument here"); + case TemplateArgument::Expression: { + Expr *E = Arg.getAsExpr(); + Expr *R = checkExpr(E); + if (!R) + return true; // If the resulting expression is new, then use it in place of the // old expression in the template argument. - if (Res.get() != E) { - TemplateArgument TA(Res.get()); - Arg = TemplateArgumentLoc(TA, Res.get()); + if (R != E) { + TemplateArgument TA(R); + ArgLoc = TemplateArgumentLoc(TA, R); } - - SugaredConverted.push_back(SugaredResult); - CanonicalConverted.push_back(CanonicalResult); break; } - case TemplateArgument::Declaration: + // As for the converted NTTP kinds, they still might need another + // conversion, as the new corresponding parameter might be diff erent. + // Ideally, we would always perform substitution starting with sugared types + // and never need these, as we would still have expressions. Since these are + // needed so rarely, it's probably a better tradeoff to just convert them + // back to expressions. case TemplateArgument::Integral: - case TemplateArgument::StructuralValue: + case TemplateArgument::Declaration: case TemplateArgument::NullPtr: - // We've already checked this template argument, so just copy - // it to the list of converted arguments. - SugaredConverted.push_back(Arg.getArgument()); - CanonicalConverted.push_back( - Context.getCanonicalTemplateArgument(Arg.getArgument())); + case TemplateArgument::StructuralValue: { + // FIXME: StructuralValue is untested here. + ExprResult R = + BuildExpressionFromNonTypeTemplateArgument(Arg, SourceLocation()); + assert(R.isUsable()); + if (!checkExpr(R.get())) + return true; break; + } case TemplateArgument::Template: case TemplateArgument::TemplateExpansion: // We were given a template template argument. It may not be ill-formed; // see below. - if (DependentTemplateName *DTN - = Arg.getArgument().getAsTemplateOrTemplatePattern() - .getAsDependentTemplateName()) { + if (DependentTemplateName *DTN = Arg.getAsTemplateOrTemplatePattern() + .getAsDependentTemplateName()) { // We have a template argument such as \c T::template X, which we // parsed as a template template argument. However, since we now // know that we need a non-type template argument, convert this // template name into an expression. DeclarationNameInfo NameInfo(DTN->getIdentifier(), - Arg.getTemplateNameLoc()); + ArgLoc.getTemplateNameLoc()); CXXScopeSpec SS; - SS.Adopt(Arg.getTemplateQualifierLoc()); + SS.Adopt(ArgLoc.getTemplateQualifierLoc()); // FIXME: the template-template arg was a DependentTemplateName, // so it was provided with a template keyword. However, its source // location is not stored in the template argument structure. @@ -5319,8 +5330,8 @@ bool Sema::CheckTemplateArgument( // If we parsed the template argument as a pack expansion, create a // pack expansion expression. - if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){ - E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc()); + if (Arg.getKind() == TemplateArgument::TemplateExpansion) { + E = ActOnPackExpansion(E.get(), ArgLoc.getTemplateEllipsisLoc()); if (E.isInvalid()) return true; } @@ -5340,8 +5351,8 @@ bool Sema::CheckTemplateArgument( // We have a template argument that actually does refer to a class // template, alias template, or template template parameter, and // therefore cannot be a non-type template argument. - Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr) - << Arg.getSourceRange(); + Diag(ArgLoc.getLocation(), diag::err_template_arg_must_be_expr) + << ArgLoc.getSourceRange(); NoteTemplateParameterLocation(*Param); return true; @@ -5357,8 +5368,8 @@ bool Sema::CheckTemplateArgument( // // We warn specifically about this case, since it can be rather // confusing for users. - QualType T = Arg.getArgument().getAsType(); - SourceRange SR = Arg.getSourceRange(); + QualType T = Arg.getAsType(); + SourceRange SR = ArgLoc.getSourceRange(); if (T->isFunctionType()) Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T; else @@ -5409,34 +5420,33 @@ bool Sema::CheckTemplateArgument( // When [the injected-class-name] is used [...] as a template-argument for // a template template-parameter [...] it refers to the class template // itself. - if (Arg.getArgument().getKind() == TemplateArgument::Type) { + if (Arg.getKind() == TemplateArgument::Type) { TemplateArgumentLoc ConvertedArg = convertTypeTemplateArgumentToTemplate( - Context, Arg.getTypeSourceInfo()->getTypeLoc()); + Context, ArgLoc.getTypeSourceInfo()->getTypeLoc()); if (!ConvertedArg.getArgument().isNull()) - Arg = ConvertedArg; + ArgLoc = ConvertedArg; } - switch (Arg.getArgument().getKind()) { + switch (Arg.getKind()) { case TemplateArgument::Null: llvm_unreachable("Should never see a NULL template argument here"); case TemplateArgument::Template: case TemplateArgument::TemplateExpansion: - if (CheckTemplateTemplateArgument(TempParm, Params, Arg, PartialOrdering, + if (CheckTemplateTemplateArgument(TempParm, Params, ArgLoc, PartialOrdering, MatchedPackOnParmToNonPackOnArg)) return true; - SugaredConverted.push_back(Arg.getArgument()); - CanonicalConverted.push_back( - Context.getCanonicalTemplateArgument(Arg.getArgument())); + SugaredConverted.push_back(Arg); + CanonicalConverted.push_back(Context.getCanonicalTemplateArgument(Arg)); break; case TemplateArgument::Expression: case TemplateArgument::Type: // We have a template template parameter but the template // argument does not refer to a template. - Diag(Arg.getLocation(), diag::err_template_arg_must_be_template) - << getLangOpts().CPlusPlus11; + Diag(ArgLoc.getLocation(), diag::err_template_arg_must_be_template) + << getLangOpts().CPlusPlus11; return true; case TemplateArgument::Declaration: diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index 15d199e7f63fec..2a5e354ff716a5 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -7335,8 +7335,10 @@ QualType TreeTransform<Derived>::TransformTemplateSpecializationType( NewTemplateArgs)) return QualType(); - // FIXME: maybe don't rebuild if all the template arguments are the same. - + // This needs to be rebuilt if either the arguments changed, or if the + // original template changed. If the template changed, and even if the + // arguments didn't change, these arguments might not correspond to their + // respective parameters, therefore needing conversions. QualType Result = getDerived().RebuildTemplateSpecializationType(Template, TL.getTemplateNameLoc(), diff --git a/clang/test/SemaTemplate/cwg2398.cpp b/clang/test/SemaTemplate/cwg2398.cpp index 1d35b574176a7e..137b94ba2641de 100644 --- a/clang/test/SemaTemplate/cwg2398.cpp +++ b/clang/test/SemaTemplate/cwg2398.cpp @@ -663,58 +663,38 @@ namespace nttp_auto { namespace nttp_partial_order { namespace t1 { - // FIXME: This should pick the second overload. template<template<short> class TT1> void f(TT1<0>); - // new-note@-1 {{here}} template<template<int> class TT2> void f(TT2<0>) {} - // new-note@-1 {{here}} template<int> struct B {}; template void f<B>(B<0>); - // new-error@-1 {{ambiguous}} } // namespace t1 namespace t2 { - // FIXME: This should pick the second overload. struct A {} a; template<template<A&> class TT1> void f(TT1<a>); - // new-note@-1 {{here}} template<template<const A&> class TT2> void f(TT2<a>) {} - // new-note@-1 {{here}} template<const A&> struct B {}; template void f<B>(B<a>); - // new-error@-1 {{ambiguous}} } // namespace t2 namespace t3 { - // FIXME: This should pick the second overload. enum A {}; template<template<A> class TT1> void f(TT1<{}>); - // new-note@-1 {{here}} template<template<int> class TT2> void f(TT2<{}>) {} - // new-note@-1 {{here}} template<int> struct B {}; template void f<B>(B<{}>); - // new-error@-1 {{ambiguous}} } // namespace t3 namespace t4 { - // FIXME: This should pick the second overload. struct A {} a; template<template<A*> class TT1> void f(TT1<&a>); - // new-note@-1 {{here}} template<template<const A*> class TT2> void f(TT2<&a>) {} - // new-note@-1 {{here}} template<const A*> struct B {}; template void f<B>(B<&a>); - // new-error@-1 {{ambiguous}} } // namespace t4 namespace t5 { - // FIXME: This should pick the second overload. struct A { int m; }; template<template<int A::*> class TT1> void f(TT1<&A::m>); - // new-note@-1 {{here}} template<template<const int A::*> class TT2> void f(TT2<&A::m>) {} - // new-note@-1 {{here}} template<const int A::*> struct B {}; template void f<B>(B<&A::m>); - // new-error@-1 {{ambiguous}} } // namespace t5 namespace t6 { // FIXME: This should pick the second overload. _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
