Teach TreeTransform how to transform a pack expansion type into
another pack expansion type. This can happen when rebuilding types in
the current instantiation.
Fixes <rdar://problem/8848837> (Clang crashing on libc++ <functional>).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123316 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateVariadic.cpp b/lib/Sema/SemaTemplateVariadic.cpp
index 63a8394..473dcb7 100644
--- a/lib/Sema/SemaTemplateVariadic.cpp
+++ b/lib/Sema/SemaTemplateVariadic.cpp
@@ -377,18 +377,13 @@
TypeSourceInfo *Sema::CheckPackExpansion(TypeSourceInfo *Pattern,
SourceLocation EllipsisLoc) {
- // C++0x [temp.variadic]p5:
- // The pattern of a pack expansion shall name one or more
- // parameter packs that are not expanded by a nested pack
- // expansion.
- if (!Pattern->getType()->containsUnexpandedParameterPack()) {
- Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
- << Pattern->getTypeLoc().getSourceRange();
- return 0;
- }
-
// Create the pack expansion type and source-location information.
- QualType Result = Context.getPackExpansionType(Pattern->getType());
+ QualType Result = CheckPackExpansion(Pattern->getType(),
+ Pattern->getTypeLoc().getSourceRange(),
+ EllipsisLoc);
+ if (Result.isNull())
+ return 0;
+
TypeSourceInfo *TSResult = Context.CreateTypeSourceInfo(Result);
PackExpansionTypeLoc TL = cast<PackExpansionTypeLoc>(TSResult->getTypeLoc());
TL.setEllipsisLoc(EllipsisLoc);
@@ -400,6 +395,22 @@
return TSResult;
}
+QualType Sema::CheckPackExpansion(QualType Pattern,
+ SourceRange PatternRange,
+ SourceLocation EllipsisLoc) {
+ // C++0x [temp.variadic]p5:
+ // The pattern of a pack expansion shall name one or more
+ // parameter packs that are not expanded by a nested pack
+ // expansion.
+ if (!Pattern->containsUnexpandedParameterPack()) {
+ Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
+ << PatternRange;
+ return QualType();
+ }
+
+ return Context.getPackExpansionType(Pattern);
+}
+
ExprResult Sema::ActOnPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc) {
if (!Pattern)
return ExprError();
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index e63cc7d..f601d5c 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -808,6 +808,16 @@
return SemaRef.Context.getElaboratedType(Keyword, NNS, T);
}
+ /// \brief Build a new pack expansion type.
+ ///
+ /// By default, builds a new PackExpansionType type from the given pattern.
+ /// Subclasses may override this routine to provide different behavior.
+ QualType RebuildPackExpansionType(QualType Pattern,
+ SourceRange PatternRange,
+ SourceLocation EllipsisLoc) {
+ return getSema().CheckPackExpansion(Pattern, PatternRange, EllipsisLoc);
+ }
+
/// \brief Build a new nested-name-specifier given the prefix and an
/// identifier that names the next step in the nested-name-specifier.
///
@@ -4232,8 +4242,24 @@
template<typename Derived>
QualType TreeTransform<Derived>::TransformPackExpansionType(TypeLocBuilder &TLB,
PackExpansionTypeLoc TL) {
- llvm_unreachable("Caller must expansion pack expansion types");
- return QualType();
+ QualType Pattern
+ = getDerived().TransformType(TLB, TL.getPatternLoc());
+ if (Pattern.isNull())
+ return QualType();
+
+ QualType Result = TL.getType();
+ if (getDerived().AlwaysRebuild() ||
+ Pattern != TL.getPatternLoc().getType()) {
+ Result = getDerived().RebuildPackExpansionType(Pattern,
+ TL.getPatternLoc().getSourceRange(),
+ TL.getEllipsisLoc());
+ if (Result.isNull())
+ return QualType();
+ }
+
+ PackExpansionTypeLoc NewT = TLB.push<PackExpansionTypeLoc>(Result);
+ NewT.setEllipsisLoc(TL.getEllipsisLoc());
+ return Result;
}
template<typename Derived>