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This commit is contained in:
Robert Sayre 2010-04-23 08:31:07 -04:00
commit 1fc88fedc3
1 changed files with 40 additions and 51 deletions
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91
js/src/jsparse.cpp
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@ -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;
}