From b34db1a8b71911be52421ed947eef9c658850eac Mon Sep 17 00:00:00 2001
From: Robert Sayre <sayrer@gmail.com>
Date: Fri, 23 Apr 2010 08:30:35 -0400
Subject: [PATCH] Backed out changeset 1af19eedbde2 -- Fix sharpSlots vs. with
 grudge-match (561011, r=mrbkap).

---
 js/src/jsparse.cpp | 91 ++++++++++++++++++++--------------------------
 1 file changed, 40 insertions(+), 51 deletions(-)

diff --git a/js/src/jsparse.cpp b/js/src/jsparse.cpp
index 9826df3533d7..d56ecce6d104 100644
--- a/js/src/jsparse.cpp
+++ b/js/src/jsparse.cpp
@@ -3226,67 +3226,20 @@ OuterLet(JSTreeContext *tc, JSStmtInfo *stmt, JSAtom *atom)
     return false;
 }
 
-/*
- * If we are generating global or eval-called-from-global code, bind a "gvar"
- * here, as soon as possible. The JSOP_GETGVAR, etc., ops speed up interpreted
- * global variable access by memoizing name-to-slot mappings during execution
- * of the script prolog (via JSOP_DEFVAR/JSOP_DEFCONST). If the memoization
- * can't be done due to a pre-existing property of the same name as the var or
- * const but incompatible attributes/getter/setter/etc, these ops devolve to
- * JSOP_NAME, etc.
- *
- * For now, don't try to lookup eval frame variables at compile time. This is
- * sub-optimal: we could handle eval-called-from-global-code gvars since eval
- * gets its own script and frame. The eval-from-function-code case is harder,
- * since functions do not atomize gvars and then reserve their atom indexes as
- * stack frame slots.
- */
-static bool
-BindGvar(JSParseNode *pn, JSTreeContext *tc)
-{
-    JS_ASSERT(pn->pn_op == JSOP_NAME);
-    JS_ASSERT(!(tc->flags & TCF_IN_FUNCTION));
-
-    if ((tc->flags & TCF_COMPILING) && !tc->parser->callerFrame) {
-        JSCodeGenerator *cg = (JSCodeGenerator *) tc;
-
-        /* Index pn->pn_atom so we can map fast global number to name. */
-        JSAtomListElement *ale = cg->atomList.add(tc->parser, pn->pn_atom);
-        if (!ale)
-            return false;
-
-        /* Defend against cg->ngvars 16-bit overflow. */
-        uintN slot = ALE_INDEX(ale);
-        if ((slot + 1) >> 16)
-            return true;
-
-        if ((uint16)(slot + 1) > cg->ngvars)
-            cg->ngvars = (uint16)(slot + 1);
-
-        pn->pn_op = JSOP_GETGVAR;
-        pn->pn_cookie = MAKE_UPVAR_COOKIE(tc->staticLevel, slot);
-        pn->pn_dflags |= PND_BOUND | PND_GVAR;
-    }
-
-    return true;
-}
-
 static JSBool
 BindVarOrConst(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc)
 {
     JSParseNode *pn = data->pn;
 
-    /* Default best op for pn is JSOP_NAME; we'll try to improve below. */
-    pn->pn_op = JSOP_NAME;
-
     if (!CheckStrictBinding(cx, tc, atom, pn))
         return false;
 
     JSStmtInfo *stmt = js_LexicalLookup(tc, atom, NULL);
 
     if (stmt && stmt->type == STMT_WITH) {
+        pn->pn_op = JSOP_NAME;
         data->fresh = false;
-        return (tc->flags & TCF_IN_FUNCTION) || BindGvar(pn, tc);
+        return JS_TRUE;
     }
 
     JSAtomListElement *ale = tc->decls.lookup(atom);
@@ -3421,8 +3374,43 @@ BindVarOrConst(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc)
     if (data->op == JSOP_DEFCONST)
         pn->pn_dflags |= PND_CONST;
 
-    if (!(tc->flags & TCF_IN_FUNCTION))
-        return BindGvar(pn, tc);
+    if (!(tc->flags & TCF_IN_FUNCTION)) {
+        /*
+         * If we are generating global or eval-called-from-global code, bind a
+         * "gvar" here, as soon as possible. The JSOP_GETGVAR, etc., ops speed
+         * up global variable access by memoizing name-to-slot mappings in the
+         * script prolog (via JSOP_DEFVAR/JSOP_DEFCONST). If the memoization
+         * can't be done due to a pre-existing property of the same name as the
+         * var or const but incompatible attributes/getter/setter/etc, these
+         * ops devolve to JSOP_NAME, etc.
+         *
+         * For now, don't try to lookup eval frame variables at compile time.
+         * Seems sub-optimal: why couldn't we find eval-called-from-a-function
+         * upvars early and possibly simplify jsemit.cpp:BindNameToSlot?
+         */
+        pn->pn_op = JSOP_NAME;
+        if ((tc->flags & TCF_COMPILING) && !tc->parser->callerFrame) {
+            JSCodeGenerator *cg = (JSCodeGenerator *) tc;
+
+            /* Index atom so we can map fast global number to name. */
+            ale = cg->atomList.add(tc->parser, atom);
+            if (!ale)
+                return JS_FALSE;
+
+            /* Defend against cg->ngvars 16-bit overflow. */
+            uintN slot = ALE_INDEX(ale);
+            if ((slot + 1) >> 16)
+                return JS_TRUE;
+
+            if ((uint16)(slot + 1) > cg->ngvars)
+                cg->ngvars = (uint16)(slot + 1);
+
+            pn->pn_op = JSOP_GETGVAR;
+            pn->pn_cookie = MAKE_UPVAR_COOKIE(tc->staticLevel, slot);
+            pn->pn_dflags |= PND_BOUND | PND_GVAR;
+        }
+        return JS_TRUE;
+    }
 
     if (atom == cx->runtime->atomState.argumentsAtom) {
         pn->pn_op = JSOP_ARGUMENTS;
@@ -3458,6 +3446,7 @@ BindVarOrConst(JSContext *cx, BindData *data, JSAtom *atom, JSTreeContext *tc)
         /* Not an argument, must be a redeclared local var. */
         JS_ASSERT(localKind == JSLOCAL_VAR || localKind == JSLOCAL_CONST);
     }
+    pn->pn_op = JSOP_NAME;
     return JS_TRUE;
 }