Start implementing support for substitution into pack expansions that
involve template parameter packs at multiple template levels that
occur within the signatures members of class templates (and partial
specializations thereof). This is a work-in-progress that is deficient
in several ways, notably:
- It only works for template type parameter packs, but we need to
also support non-type template parameter packs and template template
parameter packs.
- It doesn't keep track of the lengths of the substituted argument
packs in the expansion, so it can't properly diagnose length
mismatches.
However, this is a concrete step in the right direction.
llvm-svn: 123425
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 3abfe22..35d4b7a 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1932,6 +1932,42 @@
return QualType(SubstParm, 0);
}
+/// \brief Retrieve a
+QualType ASTContext::getSubstTemplateTypeParmPackType(
+ const TemplateTypeParmType *Parm,
+ const TemplateArgument &ArgPack) {
+#ifndef NDEBUG
+ for (TemplateArgument::pack_iterator P = ArgPack.pack_begin(),
+ PEnd = ArgPack.pack_end();
+ P != PEnd; ++P) {
+ assert(P->getKind() == TemplateArgument::Type &&"Pack contains a non-type");
+ assert(P->getAsType().isCanonical() && "Pack contains non-canonical type");
+ }
+#endif
+
+ llvm::FoldingSetNodeID ID;
+ SubstTemplateTypeParmPackType::Profile(ID, Parm, ArgPack);
+ void *InsertPos = 0;
+ if (SubstTemplateTypeParmPackType *SubstParm
+ = SubstTemplateTypeParmPackTypes.FindNodeOrInsertPos(ID, InsertPos))
+ return QualType(SubstParm, 0);
+
+ QualType Canon;
+ if (!Parm->isCanonicalUnqualified()) {
+ Canon = getCanonicalType(QualType(Parm, 0));
+ Canon = getSubstTemplateTypeParmPackType(cast<TemplateTypeParmType>(Canon),
+ ArgPack);
+ SubstTemplateTypeParmPackTypes.FindNodeOrInsertPos(ID, InsertPos);
+ }
+
+ SubstTemplateTypeParmPackType *SubstParm
+ = new (*this, TypeAlignment) SubstTemplateTypeParmPackType(Parm, Canon,
+ ArgPack);
+ Types.push_back(SubstParm);
+ SubstTemplateTypeParmTypes.InsertNode(SubstParm, InsertPos);
+ return QualType(SubstParm, 0);
+}
+
/// \brief Retrieve the template type parameter type for a template
/// parameter or parameter pack with the given depth, index, and (optionally)
/// name.