jsinterp.c

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    /*
     * Load the debugger's interrupt hook here and after calling out to native
     * functions (but not to getters, setters, or other native hooks), so we do
     * not have to reload it each time through the interpreter loop -- we hope
     * the compiler can keep it in a register.
     * XXX if it spills, we still lose
     */
#define LOAD_INTERRUPT_HANDLER(rt)  (interruptHandler = (rt)->interruptHandler)

    LOAD_INTERRUPT_HANDLER(rt);

    pc = script->code;
    endpc = pc + script->length;
    depth = (jsint) script->depth;
    len = -1;

    /* Check for too much js_Interpret nesting, or too deep a C stack. */
    if (++cx->interpLevel == MAX_INTERP_LEVEL ||
        !JS_CHECK_STACK_SIZE(cx, stackDummy)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_OVER_RECURSED);
        ok = JS_FALSE;
        goto out;
    }

    /*
     * Allocate operand and pc stack slots for the script's worst-case depth.
     */
    newsp = js_AllocRawStack(cx, (uintN)(2 * depth), &mark);
    if (!newsp) {
        ok = JS_FALSE;
        goto out;
    }
    sp = newsp + depth;
    fp->spbase = sp;
    fp->spend = sp + depth;
    SAVE_SP(fp);

    while (pc < endpc) {
        fp->pc = pc;
        op = (JSOp) *pc;
      do_op:
        cs = &js_CodeSpec[op];
        len = cs->length;

#ifdef DEBUG
        tracefp = (FILE *) cx->tracefp;
        if (tracefp) {
            intN nuses, n;

            fprintf(tracefp, "%4u: ", js_PCToLineNumber(cx, script, pc));
            js_Disassemble1(cx, script, pc,
                            PTRDIFF(pc, script->code, jsbytecode), JS_FALSE,
                            tracefp);
            nuses = cs->nuses;
            if (nuses) {
                SAVE_SP(fp);
                for (n = -nuses; n < 0; n++) {
                    str = js_DecompileValueGenerator(cx, n, sp[n], NULL);
                    if (str != NULL) {
                        fprintf(tracefp, "%s %s",
                                (n == -nuses) ? "  inputs:" : ",",
                                JS_GetStringBytes(str));
                    }
                }
                fprintf(tracefp, " @ %td\n", sp - fp->spbase);
            }
        }
#endif

        if (interruptHandler) {
            SAVE_SP(fp);
            switch (interruptHandler(cx, script, pc, &rval,
                                     rt->interruptHandlerData)) {
              case JSTRAP_ERROR:
                ok = JS_FALSE;
                goto out;
              case JSTRAP_CONTINUE:
                break;
              case JSTRAP_RETURN:
                fp->rval = rval;
                goto out;
#if JS_HAS_EXCEPTIONS
              case JSTRAP_THROW:
                cx->throwing = JS_TRUE;
                cx->exception = rval;
                ok = JS_FALSE;
                goto out;
#endif /* JS_HAS_EXCEPTIONS */
              default:;
            }
            LOAD_INTERRUPT_HANDLER(rt);
        }

        switch (op) {
          case JSOP_NOP:
            break;

          case JSOP_GROUP:
            obj = NULL;
            break;

          case JSOP_PUSH:
            PUSH_OPND(JSVAL_VOID);
            break;

          case JSOP_POP:
            sp--;
            break;

          case JSOP_POP2:
            sp -= 2;
            break;

	  case JSOP_FLASHSWAP:
	    id = pc[1] << 8 | pc[2];
	    ltmp = sp[-1];
	    sp[-1] = sp[-id];
	    sp[-id] = ltmp;
	    break;
          case JSOP_SWAP:
            /*
             * N.B. JSOP_SWAP doesn't swap the corresponding generating pcs
             * for the operands it swaps.
             */
            ltmp = sp[-1];
            sp[-1] = sp[-2];
            sp[-2] = ltmp;
            break;

          case JSOP_POPV:
            *result = POP_OPND();
            break;

          case JSOP_ENTERWITH:
            rval = FETCH_OPND(-1);
            VALUE_TO_OBJECT(cx, rval, obj);
            withobj = js_NewObject(cx, &js_WithClass, obj, fp->scopeChain);
            if (!withobj)
                goto out;
            fp->scopeChain = withobj;
            STORE_OPND(-1, OBJECT_TO_JSVAL(withobj));
            break;

          case JSOP_LEAVEWITH:
            rval = POP_OPND();
            JS_ASSERT(JSVAL_IS_OBJECT(rval));
            withobj = JSVAL_TO_OBJECT(rval);
            JS_ASSERT(OBJ_GET_CLASS(cx, withobj) == &js_WithClass);

            rval = OBJ_GET_SLOT(cx, withobj, JSSLOT_PARENT);
            JS_ASSERT(JSVAL_IS_OBJECT(rval));
            fp->scopeChain = JSVAL_TO_OBJECT(rval);
            break;

          case JSOP_SETRVAL:
            fp->rval = POP_OPND();
            break;

          case JSOP_RETURN:
            CHECK_BRANCH(-1);
            fp->rval = POP_OPND();
            /* FALL THROUGH */

          case JSOP_RETRVAL:    /* fp->rval already set */
            if (inlineCallCount)
          inline_return:
            {
                JSInlineFrame *ifp = (JSInlineFrame *) fp;
                void *hookData = ifp->hookData;

                if (hookData) {
                    JSInterpreterHook hook = cx->runtime->callHook;
                    if (hook) {
                        hook(cx, fp, JS_FALSE, &ok, hookData);
                        LOAD_INTERRUPT_HANDLER(rt);
                    }
                }
#if JS_HAS_ARGS_OBJECT
                if (fp->argsobj)
                    ok &= js_PutArgsObject(cx, fp);
#endif

                /* Restore context version only if callee hasn't set version. */
                if (cx->version == currentVersion) {
                    currentVersion = ifp->callerVersion;
                    if (currentVersion != cx->version)
                        JS_SetVersion(cx, currentVersion);
                }

                /* Store the return value in the caller's operand frame. */
                vp = fp->argv - 2;
                *vp = fp->rval;

                /* Restore cx->fp and release the inline frame's space. */
                cx->fp = fp = fp->down;
                JS_ARENA_RELEASE(&cx->stackPool, ifp->mark);

                /* Restore sp to point just above the return value. */
                fp->sp = vp + 1;
                RESTORE_SP(fp);

                /* Restore the calling script's interpreter registers. */
                script = fp->script;
                depth = (jsint) script->depth;
                pc = fp->pc;
                endpc = script->code + script->length;

                /* Store the generating pc for the return value. */
                vp[-depth] = (jsval)pc;

                /* Set remaining variables for 'goto advance_pc'. */
                op = (JSOp) *pc;
                cs = &js_CodeSpec[op];
                len = cs->length;

                /* Resume execution in the calling frame. */
                inlineCallCount--;
                if (ok)
                    goto advance_pc;
            }
            goto out;

#if JS_HAS_SWITCH_STATEMENT
          case JSOP_DEFAULT:
            (void) POP();
            /* FALL THROUGH */
#endif
          case JSOP_GOTO:
            len = GET_JUMP_OFFSET(pc);
            CHECK_BRANCH(len);
            break;

          case JSOP_IFEQ:
            POP_BOOLEAN(cx, rval, cond);
            if (cond == JS_FALSE) {
                len = GET_JUMP_OFFSET(pc);
                CHECK_BRANCH(len);
            }
            break;

          case JSOP_IFNE:
            POP_BOOLEAN(cx, rval, cond);
            if (cond != JS_FALSE) {
                len = GET_JUMP_OFFSET(pc);
                CHECK_BRANCH(len);
            }
            break;

          case JSOP_OR:
            POP_BOOLEAN(cx, rval, cond);
            if (cond == JS_TRUE) {
                len = GET_JUMP_OFFSET(pc);
                PUSH_OPND(rval);
            }
            break;

          case JSOP_AND:
            POP_BOOLEAN(cx, rval, cond);
            if (cond == JS_FALSE) {
                len = GET_JUMP_OFFSET(pc);
                PUSH_OPND(rval);
            }
            break;


#if JS_HAS_SWITCH_STATEMENT
          case JSOP_DEFAULTX:
            (void) POP();
            /* FALL THROUGH */
#endif
          case JSOP_GOTOX:
            len = GET_JUMPX_OFFSET(pc);
            CHECK_BRANCH(len);
            break;

          case JSOP_IFEQX:
            POP_BOOLEAN(cx, rval, cond);
            if (cond == JS_FALSE) {
                len = GET_JUMPX_OFFSET(pc);
                CHECK_BRANCH(len);
            }
            break;

          case JSOP_IFNEX:
            POP_BOOLEAN(cx, rval, cond);
            if (cond != JS_FALSE) {
                len = GET_JUMPX_OFFSET(pc);
                CHECK_BRANCH(len);
            }
            break;

          case JSOP_ORX:
            POP_BOOLEAN(cx, rval, cond);
            if (cond == JS_TRUE) {
                len = GET_JUMPX_OFFSET(pc);
                PUSH_OPND(rval);
            }
            break;

          case JSOP_ANDX:
            POP_BOOLEAN(cx, rval, cond);
            if (cond == JS_FALSE) {
                len = GET_JUMPX_OFFSET(pc);
                PUSH_OPND(rval);
            }
            break;

          case JSOP_TOOBJECT:
            SAVE_SP(fp);
            ok = js_ValueToObject(cx, FETCH_OPND(-1), &obj);
            if (!ok)
                goto out;
            STORE_OPND(-1, OBJECT_TO_JSVAL(obj));
            break;

#define FETCH_ELEMENT_ID(n, id)                                               \
    JS_BEGIN_MACRO                                                            \
        /* If the index is not a jsint, atomize it. */                        \
        id = (jsid) FETCH_OPND(n);                                            \
        if (JSVAL_IS_INT(id)) {                                               \
            atom = NULL;                                                      \
        } else {                                                              \
            SAVE_SP(fp);                                                      \
            atom = js_ValueToStringAtom(cx, (jsval)id);			      \
            if (!atom) {                                                      \
                ok = JS_FALSE;                                                \
                goto out;                                                     \
            }                                                                 \
            id = (jsid)atom;                                                  \
        }                                                                     \
    JS_END_MACRO

#define POP_ELEMENT_ID(id)                                                    \
    JS_BEGIN_MACRO                                                            \
        FETCH_ELEMENT_ID(-1, id);                                             \
        sp--;                                                                 \
    JS_END_MACRO

#if JS_HAS_IN_OPERATOR
          case JSOP_IN:
            SAVE_SP(fp);
            rval = FETCH_OPND(-1);
            if (JSVAL_IS_PRIMITIVE(rval)) {
                str = js_DecompileValueGenerator(cx, -1, rval, NULL);
                if (str) {
                    JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                                         JSMSG_IN_NOT_OBJECT,
                                         JS_GetStringBytes(str));
                }
                ok = JS_FALSE;
                goto out;
            }
            obj = JSVAL_TO_OBJECT(rval);
            FETCH_ELEMENT_ID(-2, id);
            ok = OBJ_LOOKUP_PROPERTY(cx, obj, id, &obj2, &prop);
            if (!ok)
                goto out;
            sp--;
            STORE_OPND(-1, BOOLEAN_TO_JSVAL(prop != NULL));
            if (prop)
                OBJ_DROP_PROPERTY(cx, obj2, prop);
            break;
#endif /* JS_HAS_IN_OPERATOR */

          case JSOP_FORPROP:
            /*
             * Handle JSOP_FORPROP first,