diff options
Diffstat (limited to 'clang/lib/Sema/TreeTransform.h')
| -rw-r--r-- | clang/lib/Sema/TreeTransform.h | 84 |
1 files changed, 77 insertions, 7 deletions
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h index e2bfb05088b..7eee4441740 100644 --- a/clang/lib/Sema/TreeTransform.h +++ b/clang/lib/Sema/TreeTransform.h @@ -89,6 +89,23 @@ using namespace sema; /// (\c getBaseLocation(), \c getBaseEntity()). template<typename Derived> class TreeTransform { + /// \brief Private RAII object that helps us forget and then re-remember + /// the template argument corresponding to a partially-substituted parameter + /// pack. + class ForgetPartiallySubstitutedPackRAII { + Derived &Self; + TemplateArgument Old; + + public: + ForgetPartiallySubstitutedPackRAII(Derived &Self) : Self(Self) { + Old = Self.ForgetPartiallySubstitutedPack(); + } + + ~ForgetPartiallySubstitutedPackRAII() { + Self.RememberPartiallySubstitutedPack(Old); + } + }; + protected: Sema &SemaRef; @@ -204,6 +221,11 @@ public: /// expand the corresponding pack expansions into separate arguments. When /// set, \c NumExpansions must also be set. /// + /// \param RetainExpansion Whether the caller should add an unexpanded + /// pack expansion after all of the expanded arguments. This is used + /// when extending explicitly-specified template argument packs per + /// C++0x [temp.arg.explicit]p9. + /// /// \param NumExpansions The number of separate arguments that will be in /// the expanded form of the corresponding pack expansion. Must be set when /// \c ShouldExpand is \c true. @@ -217,11 +239,28 @@ public: const UnexpandedParameterPack *Unexpanded, unsigned NumUnexpanded, bool &ShouldExpand, + bool &RetainExpansion, unsigned &NumExpansions) { ShouldExpand = false; return false; } + /// \brief "Forget" about the partially-substituted pack template argument, + /// when performing an instantiation that must preserve the parameter pack + /// use. + /// + /// This routine is meant to be overridden by the template instantiator. + TemplateArgument ForgetPartiallySubstitutedPack() { + return TemplateArgument(); + } + + /// \brief "Remember" the partially-substituted pack template argument + /// after performing an instantiation that must preserve the parameter pack + /// use. + /// + /// This routine is meant to be overridden by the template instantiator. + void RememberPartiallySubstitutedPack(TemplateArgument Arg) { } + /// \brief Note to the derived class when a function parameter pack is /// being expanded. void ExpandingFunctionParameterPack(ParmVarDecl *Pack) { } @@ -2250,12 +2289,14 @@ bool TreeTransform<Derived>::TransformExprs(Expr **Inputs, // Determine whether the set of unexpanded parameter packs can and should // be expanded. bool Expand = true; + bool RetainExpansion = false; unsigned NumExpansions = 0; if (getDerived().TryExpandParameterPacks(Expansion->getEllipsisLoc(), Pattern->getSourceRange(), Unexpanded.data(), Unexpanded.size(), - Expand, NumExpansions)) + Expand, RetainExpansion, + NumExpansions)) return true; if (!Expand) { @@ -2770,12 +2811,15 @@ bool TreeTransform<Derived>::TransformTemplateArguments(InputIterator First, // Determine whether the set of unexpanded parameter packs can and should // be expanded. bool Expand = true; + bool RetainExpansion = false; unsigned NumExpansions = 0; if (getDerived().TryExpandParameterPacks(Ellipsis, Pattern.getSourceRange(), Unexpanded.data(), Unexpanded.size(), - Expand, NumExpansions)) + Expand, + RetainExpansion, + NumExpansions)) return true; if (!Expand) { @@ -2806,6 +2850,8 @@ bool TreeTransform<Derived>::TransformTemplateArguments(InputIterator First, Outputs.addArgument(Out); } + // FIXME: Variadic templates retain expansion! + continue; } @@ -3415,12 +3461,15 @@ bool TreeTransform<Derived>:: // Determine whether we should expand the parameter packs. bool ShouldExpand = false; + bool RetainExpansion = false; unsigned NumExpansions = 0; if (getDerived().TryExpandParameterPacks(ExpansionTL.getEllipsisLoc(), Pattern.getSourceRange(), Unexpanded.data(), Unexpanded.size(), - ShouldExpand, NumExpansions)) { + ShouldExpand, + RetainExpansion, + NumExpansions)) { return true; } @@ -3439,7 +3488,21 @@ bool TreeTransform<Derived>:: if (PVars) PVars->push_back(NewParm); } - + + // If we're supposed to retain a pack expansion, do so by temporarily + // forgetting the partially-substituted parameter pack. + if (RetainExpansion) { + ForgetPartiallySubstitutedPackRAII Forget(getDerived()); + ParmVarDecl *NewParm + = getDerived().TransformFunctionTypeParam(OldParm); + if (!NewParm) + return true; + + OutParamTypes.push_back(NewParm->getType()); + if (PVars) + PVars->push_back(NewParm); + } + // We're done with the pack expansion. continue; } @@ -3472,11 +3535,14 @@ bool TreeTransform<Derived>:: // Determine whether we should expand the parameter packs. bool ShouldExpand = false; + bool RetainExpansion = false; unsigned NumExpansions = 0; if (getDerived().TryExpandParameterPacks(Loc, SourceRange(), Unexpanded.data(), Unexpanded.size(), - ShouldExpand, NumExpansions)) { + ShouldExpand, + RetainExpansion, + NumExpansions)) { return true; } @@ -3498,6 +3564,8 @@ bool TreeTransform<Derived>:: continue; } + // FIXME: Variadic templates retain pack expansion! + // We'll substitute the parameter now without expanding the pack // expansion. OldType = Expansion->getPattern(); @@ -6674,13 +6742,15 @@ TreeTransform<Derived>::TransformSizeOfPackExpr(SizeOfPackExpr *E) { // so UnexpandedParameterPack Unexpanded(E->getPack(), E->getPackLoc()); bool ShouldExpand = false; + bool RetainExpansion = false; unsigned NumExpansions = 0; if (getDerived().TryExpandParameterPacks(E->getOperatorLoc(), E->getPackLoc(), &Unexpanded, 1, - ShouldExpand, NumExpansions)) + ShouldExpand, RetainExpansion, + NumExpansions)) return ExprError(); - if (!ShouldExpand) + if (!ShouldExpand || RetainExpansion) return SemaRef.Owned(E); // We now know the length of the parameter pack, so build a new expression |
