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, 21 insertions, 18 deletions

diff --git a/include/clang/AST/StmtObjC.h b/include/clang/AST/StmtObjC.h
index 269aa4c6da..1800a71f91 100644
--- a/include/clang/AST/StmtObjC.h
+++ b/include/clang/AST/StmtObjC.h
@@ -55,7 +55,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation Loc) { RParenLoc = Loc; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(ForLoc, SubExprs[BODY]->getLocEnd());
   }
   static bool classof(const Stmt *T) {
@@ -64,8 +64,9 @@ public:
   static bool classof(const ObjCForCollectionStmt *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubExprs[0], &SubExprs[END_EXPR]);
+  }
 };
 
 /// ObjCAtCatchStmt - This represents objective-c's @catch statement.
@@ -102,7 +103,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation Loc) { RParenLoc = Loc; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(AtCatchLoc, Body->getLocEnd());
   }
 
@@ -113,8 +114,7 @@ public:
   }
   static bool classof(const ObjCAtCatchStmt *) { return true; }
 
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Body, &Body + 1); }
 };
 
 /// ObjCAtFinallyStmt - This represent objective-c's @finally Statement
@@ -133,7 +133,7 @@ public:
   Stmt *getFinallyBody() { return AtFinallyStmt; }
   void setFinallyBody(Stmt *S) { AtFinallyStmt = S; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(AtFinallyLoc, AtFinallyStmt->getLocEnd());
   }
 
@@ -145,8 +145,9 @@ public:
   }
   static bool classof(const ObjCAtFinallyStmt *) { return true; }
 
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&AtFinallyStmt, &AtFinallyStmt+1);
+  }
 };
 
 /// ObjCAtTryStmt - This represent objective-c's over-all
@@ -239,15 +240,17 @@ public:
     getStmts()[1 + NumCatchStmts] = S; 
   }
 
-  virtual SourceRange getSourceRange() const;
+  SourceRange getSourceRange() const;
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == ObjCAtTryStmtClass;
   }
   static bool classof(const ObjCAtTryStmt *) { return true; }
 
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(getStmts(),
+                       getStmts() + 1 + NumCatchStmts + HasFinally);
+  }
 };
 
 /// ObjCAtSynchronizedStmt - This is for objective-c's @synchronized statement.
@@ -291,7 +294,7 @@ public:
   }
   void setSynchExpr(Stmt *S) { SubStmts[SYNC_EXPR] = S; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(AtSynchronizedLoc, getSynchBody()->getLocEnd());
   }
 
@@ -300,8 +303,9 @@ public:
   }
   static bool classof(const ObjCAtSynchronizedStmt *) { return true; }
 
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubStmts[0], &SubStmts[0]+END_EXPR);
+  }
 };
 
 /// ObjCAtThrowStmt - This represents objective-c's @throw statement.
@@ -323,7 +327,7 @@ public:
   SourceLocation getThrowLoc() { return AtThrowLoc; }
   void setThrowLoc(SourceLocation Loc) { AtThrowLoc = Loc; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     if (Throw)
       return SourceRange(AtThrowLoc, Throw->getLocEnd());
     else
@@ -335,8 +339,7 @@ public:
   }
   static bool classof(const ObjCAtThrowStmt *) { return true; }
 
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Throw, &Throw+1); }
 };
 
 }  // end namespace clang