Implement the sizeof...(pack) expression to compute the length of a
parameter pack.

Note that we're missing proper libclang support for the new
SizeOfPackExpr expression node.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122813 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTWriterStmt.cpp b/lib/Serialization/ASTWriterStmt.cpp
index 27261db..af066bb 100644
--- a/lib/Serialization/ASTWriterStmt.cpp
+++ b/lib/Serialization/ASTWriterStmt.cpp
@@ -151,6 +151,7 @@
     void VisitBinaryTypeTraitExpr(BinaryTypeTraitExpr *E);
     void VisitCXXNoexceptExpr(CXXNoexceptExpr *E);
     void VisitPackExpansionExpr(PackExpansionExpr *E);
+    void VisitSizeOfPackExpr(SizeOfPackExpr *E);
     void VisitOpaqueValueExpr(OpaqueValueExpr *E);
   };
 }
@@ -1303,6 +1304,16 @@
   Code = serialization::EXPR_PACK_EXPANSION;
 }
 
+void ASTStmtWriter::VisitSizeOfPackExpr(SizeOfPackExpr *E) {
+  VisitExpr(E);
+  Writer.AddSourceLocation(E->OperatorLoc, Record);
+  Writer.AddSourceLocation(E->PackLoc, Record);
+  Writer.AddSourceLocation(E->RParenLoc, Record);
+  Record.push_back(E->Length);
+  Writer.AddDeclRef(E->Pack, Record);
+  Code = serialization::EXPR_SIZEOF_PACK;
+}
+
 void ASTStmtWriter::VisitOpaqueValueExpr(OpaqueValueExpr *E) {
   VisitExpr(E);
   Code = serialization::EXPR_OPAQUE_VALUE;