Variadic templates: extend Type, NestedNameSpecifier, TemplateName,

and TemplateArgument with an operation that determines whether there
are any unexpanded parameter packs within that construct. Use this
information to diagnose the appearance of the names of parameter packs
that have not been expanded (C++ [temp.variadic]p5). Since this
property is checked often (every declaration, ever expression
statement, etc.), we extend Type and Expr with a bit storing the
result of this computation, rather than walking the AST each time to
determine whether any unexpanded parameter packs occur.

This commit is deficient in several ways, which will be remedied with
future commits:
  - Expr has a bit to store the presence of an unexpanded parameter
  pack, but it is never set.
  - The error messages don't point out where the unexpanded parameter
  packs were named in the type/expression, but they should. 
  - We don't check for unexpanded parameter packs in all of the places
  where we should.
  - Testing is sparse, pending the resolution of the above three
  issues.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@121724 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/Serialization/ASTReaderStmt.cpp b/lib/Serialization/ASTReaderStmt.cpp
index 353477d963..aa669b34b3 100644
--- a/lib/Serialization/ASTReaderStmt.cpp
+++ b/lib/Serialization/ASTReaderStmt.cpp
@@ -59,7 +59,7 @@ namespace clang {
 
     /// \brief The number of record fields required for the Expr class
     /// itself.
-    static const unsigned NumExprFields = NumStmtFields + 5;
+    static const unsigned NumExprFields = NumStmtFields + 6;
     
     /// \brief Read and initialize a ExplicitTemplateArgumentList structure.
     void ReadExplicitTemplateArgumentList(ExplicitTemplateArgumentList &ArgList,
@@ -399,6 +399,7 @@ void ASTStmtReader::VisitExpr(Expr *E) {
   E->setType(Reader.GetType(Record[Idx++]));
   E->setTypeDependent(Record[Idx++]);
   E->setValueDependent(Record[Idx++]);
+  E->ExprBits.ContainsUnexpandedParameterPack = Record[Idx++];
   E->setValueKind(static_cast<ExprValueKind>(Record[Idx++]));
   E->setObjectKind(static_cast<ExprObjectKind>(Record[Idx++]));
   assert(Idx == NumExprFields && "Incorrect expression field count");