From 29c42f2a25d6ce7008b9164be2cfc8f30e678ab9 Mon Sep 17 00:00:00 2001 From: Douglas Gregor Date: Fri, 24 Feb 2012 07:38:34 +0000 Subject: Implement a new type trait __is_trivially_constructible(T, Args...) that provides the behavior of the C++11 library trait std::is_trivially_constructible, which can't be implemented purely as a library. Since __is_trivially_constructible can have zero or more arguments, I needed to add Yet Another Type Trait Expression Class, this one handling arbitrary arguments. The next step will be to migrate UnaryTypeTrait and BinaryTypeTrait over to this new, more general TypeTrait class. Fixes the Clang side of / PR12038. llvm-svn: 151352 --- clang/lib/Sema/TreeTransform.h | 133 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) (limited to 'clang/lib/Sema/TreeTransform.h') diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index 58d6a22a288..f0b5f4e2419 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -2022,6 +2022,17 @@ public: return getSema().BuildBinaryTypeTrait(Trait, StartLoc, LhsT, RhsT, RParenLoc); } + /// \brief Build a new type trait expression. + /// + /// By default, performs semantic analysis to build the new expression. + /// Subclasses may override this routine to provide different behavior. + ExprResult RebuildTypeTrait(TypeTrait Trait, + SourceLocation StartLoc, + ArrayRef Args, + SourceLocation RParenLoc) { + return getSema().BuildTypeTrait(Trait, StartLoc, Args, RParenLoc); + } + /// \brief Build a new array type trait expression. /// /// By default, performs semantic analysis to build the new expression. @@ -7434,6 +7445,128 @@ TreeTransform::TransformBinaryTypeTraitExpr(BinaryTypeTraitExpr *E) { E->getLocEnd()); } +template +ExprResult +TreeTransform::TransformTypeTraitExpr(TypeTraitExpr *E) { + bool ArgChanged = false; + llvm::SmallVector Args; + for (unsigned I = 0, N = E->getNumArgs(); I != N; ++I) { + TypeSourceInfo *From = E->getArg(I); + TypeLoc FromTL = From->getTypeLoc(); + if (!isa(FromTL)) { + TypeLocBuilder TLB; + TLB.reserve(FromTL.getFullDataSize()); + QualType To = getDerived().TransformType(TLB, FromTL); + if (To.isNull()) + return ExprError(); + + if (To == From->getType()) + Args.push_back(From); + else { + Args.push_back(TLB.getTypeSourceInfo(SemaRef.Context, To)); + ArgChanged = true; + } + continue; + } + + ArgChanged = true; + + // We have a pack expansion. Instantiate it. + PackExpansionTypeLoc ExpansionTL = cast(FromTL); + TypeLoc PatternTL = ExpansionTL.getPatternLoc(); + SmallVector Unexpanded; + SemaRef.collectUnexpandedParameterPacks(PatternTL, Unexpanded); + + // Determine whether the set of unexpanded parameter packs can and should + // be expanded. + bool Expand = true; + bool RetainExpansion = false; + llvm::Optional OrigNumExpansions + = ExpansionTL.getTypePtr()->getNumExpansions(); + llvm::Optional NumExpansions = OrigNumExpansions; + if (getDerived().TryExpandParameterPacks(ExpansionTL.getEllipsisLoc(), + PatternTL.getSourceRange(), + Unexpanded, + Expand, RetainExpansion, + NumExpansions)) + return ExprError(); + + if (!Expand) { + // The transform has determined that we should perform a simple + // transformation on the pack expansion, producing another pack + // expansion. + Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(getSema(), -1); + + TypeLocBuilder TLB; + TLB.reserve(From->getTypeLoc().getFullDataSize()); + + QualType To = getDerived().TransformType(TLB, PatternTL); + if (To.isNull()) + return ExprError(); + + To = getDerived().RebuildPackExpansionType(To, + PatternTL.getSourceRange(), + ExpansionTL.getEllipsisLoc(), + NumExpansions); + if (To.isNull()) + return ExprError(); + + PackExpansionTypeLoc ToExpansionTL + = TLB.push(To); + ToExpansionTL.setEllipsisLoc(ExpansionTL.getEllipsisLoc()); + Args.push_back(TLB.getTypeSourceInfo(SemaRef.Context, To)); + continue; + } + + // Expand the pack expansion by substituting for each argument in the + // pack(s). + for (unsigned I = 0; I != *NumExpansions; ++I) { + Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I); + TypeLocBuilder TLB; + TLB.reserve(PatternTL.getFullDataSize()); + QualType To = getDerived().TransformType(TLB, PatternTL); + if (To.isNull()) + return ExprError(); + + Args.push_back(TLB.getTypeSourceInfo(SemaRef.Context, To)); + } + + if (!RetainExpansion) + continue; + + // If we're supposed to retain a pack expansion, do so by temporarily + // forgetting the partially-substituted parameter pack. + ForgetPartiallySubstitutedPackRAII Forget(getDerived()); + + TypeLocBuilder TLB; + TLB.reserve(From->getTypeLoc().getFullDataSize()); + + QualType To = getDerived().TransformType(TLB, PatternTL); + if (To.isNull()) + return ExprError(); + + To = getDerived().RebuildPackExpansionType(To, + PatternTL.getSourceRange(), + ExpansionTL.getEllipsisLoc(), + NumExpansions); + if (To.isNull()) + return ExprError(); + + PackExpansionTypeLoc ToExpansionTL + = TLB.push(To); + ToExpansionTL.setEllipsisLoc(ExpansionTL.getEllipsisLoc()); + Args.push_back(TLB.getTypeSourceInfo(SemaRef.Context, To)); + } + + if (!getDerived().AlwaysRebuild() && !ArgChanged) + return SemaRef.Owned(E); + + return getDerived().RebuildTypeTrait(E->getTrait(), + E->getLocStart(), + Args, + E->getLocEnd()); +} + template ExprResult TreeTransform::TransformArrayTypeTraitExpr(ArrayTypeTraitExpr *E) { -- cgit v1.2.3