Remove vtables from the Stmt hierarchy; this was pretty easy as

there were only three virtual methods of any significance.

The primary way to grab child iterators now is with
  Stmt::child_range children();
  Stmt::const_child_range children() const;
where a child_range is just a std::pair of iterators suitable for
being llvm::tie'd to some locals.  I've left the old child_begin()
and child_end() accessors in place, but it's probably a substantial
penalty to grab the iterators individually now, since the
switch-based dispatch is kindof inherently slower than vtable
dispatch.  Grabbing them together is probably a slight win over the
status quo, although of course we could've achieved that with vtables, too.

I also reclassified SwitchCase (correctly) as an abstract Stmt
class, which (as the first such class that wasn't an Expr subclass)
required some fiddling in a few places.

There are somewhat gross metaprogramming hooks in place to ensure
that new statements/expressions continue to implement
getSourceRange() and children().  I had to work around a recent clang
bug;  dgregor actually fixed it already, but I didn't want to
introduce a selfhosting dependency on ToT.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125183 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 7 deletions

diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index 2a82869786..bd110bd1f6 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -2280,6 +2280,7 @@ StmtResult TreeTransform<Derived>::TransformStmt(Stmt *S) {
   // Transform individual statement nodes
 #define STMT(Node, Parent)                                              \
   case Stmt::Node##Class: return getDerived().Transform##Node(cast<Node>(S));
+#define ABSTRACT_STMT(Node)
 #define EXPR(Node, Parent)
 #include "clang/AST/StmtNodes.inc"
 
@@ -4831,13 +4832,6 @@ TreeTransform<Derived>::TransformDeclStmt(DeclStmt *S) {
 
 template<typename Derived>
 StmtResult
-TreeTransform<Derived>::TransformSwitchCase(SwitchCase *S) {
-  assert(false && "SwitchCase is abstract and cannot be transformed");
-  return SemaRef.Owned(S);
-}
-
-template<typename Derived>
-StmtResult
 TreeTransform<Derived>::TransformAsmStmt(AsmStmt *S) {
   
   ASTOwningVector<Expr*> Constraints(getSema());