C++ JSContext::getPendingException方法代码示例

ErrorCopier::~ErrorCopier()
{
    JSContext *cx = ac.ref().context();
    if (ac.ref().origin() != cx->compartment && cx->isExceptionPending()) {
        RootedValue exc(cx, cx->getPendingException());
        if (exc.isObject() && exc.toObject().isError() && exc.toObject().getPrivate()) {
            cx->clearPendingException();
            ac.destroy();
            Rooted<JSObject*> errObj(cx, &exc.toObject());
            JSObject *copyobj = js_CopyErrorObject(cx, errObj, scope);
            if (copyobj)
                cx->setPendingException(ObjectValue(*copyobj));
        }
    }
}

ErrorCopier::~ErrorCopier()
{
    JSContext* cx = ac->context()->asJSContext();
    if (ac->origin() != cx->compartment() && cx->isExceptionPending()) {
        RootedValue exc(cx);
        if (cx->getPendingException(&exc) && exc.isObject() && exc.toObject().is<ErrorObject>()) {
            cx->clearPendingException();
            ac.reset();
            Rooted<ErrorObject*> errObj(cx, &exc.toObject().as<ErrorObject>());
            JSObject* copyobj = CopyErrorObject(cx, errObj);
            if (copyobj)
                cx->setPendingException(ObjectValue(*copyobj));
        }
    }
}

ErrorCopier::~ErrorCopier()
{
    JSContext *cx = ac.context;
    if (cx->compartment == ac.destination &&
        ac.origin != ac.destination &&
        cx->isExceptionPending())
    {
        Value exc = cx->getPendingException();
        if (exc.isObject() && exc.toObject().isError() && exc.toObject().getPrivate()) {
            cx->clearPendingException();
            ac.leave();
            JSObject *copyobj = js_CopyErrorObject(cx, &exc.toObject(), scope);
            if (copyobj)
                cx->setPendingException(ObjectValue(*copyobj));
        }
    }
}

ErrorCopier::~ErrorCopier()
{
    JSContext* cx = ac->context();

    // The provenance of Debugger.DebuggeeWouldRun is the topmost locking
    // debugger compartment; it should not be copied around.
    if (ac->origin() != cx->compartment() &&
        cx->isExceptionPending() &&
        !cx->isThrowingDebuggeeWouldRun())
    {
        RootedValue exc(cx);
        if (cx->getPendingException(&exc) && exc.isObject() && exc.toObject().is<ErrorObject>()) {
            cx->clearPendingException();
            ac.reset();
            Rooted<ErrorObject*> errObj(cx, &exc.toObject().as<ErrorObject>());
            JSObject* copyobj = CopyErrorObject(cx, errObj);
            if (copyobj)
                cx->setPendingException(ObjectValue(*copyobj));
        }
    }
}

//.........这里部分代码省略.........
                case JSTRAP_THROW:
                    cx->setPendingException(rval);
                    break;

                default:
                    JS_NOT_REACHED("bad onExceptionUnwind status");
                }
            }
        }

        pc = FindExceptionHandler(cx);
        if (pc)
            break;

        // The JIT guarantees that ScriptDebugEpilogue() and ScriptEpilogue()
        // have always been run upon exiting to its caller. This is important
        // for consistency, where execution modes make similar guarantees about
        // prologues and epilogues. Interpret(), and Invoke() all rely on this
        // property.
        JS_ASSERT(!f.fp()->finishedInInterpreter());
        UnwindScope(cx, 0);
        f.regs.setToEndOfScript();

        if (cx->compartment->debugMode()) {
            // This can turn a throw or error into a healthy return. Note that
            // we will run ScriptDebugEpilogue again (from AnyFrameEpilogue);
            // ScriptDebugEpilogue is prepared for this eventuality.
            if (js::ScriptDebugEpilogue(cx, f.fp(), false))
                return cx->jaegerRuntime().forceReturnFromExternC();
        }


        f.fp()->epilogue(f.cx);

        // Don't remove the last frame, this is the responsibility of
        // JaegerShot()'s caller. We only guarantee that ScriptEpilogue()
        // has been run.
        if (f.entryfp == f.fp())
            break;

        f.cx->stack.popInlineFrame(f.regs);
        DebugOnly<JSOp> op = JSOp(*f.regs.pc);
        JS_ASSERT(op == JSOP_CALL ||
                  op == JSOP_NEW ||
                  op == JSOP_EVAL ||
                  op == JSOP_FUNCALL ||
                  op == JSOP_FUNAPPLY);
        f.regs.pc += JSOP_CALL_LENGTH;
    }

    JS_ASSERT(&cx->regs() == &f.regs);

    if (!pc)
        return NULL;

    StackFrame *fp = cx->fp();
    RootedScript script(cx, fp->script());

    /*
     * Fall back to EnterMethodJIT and finish the frame in the interpreter.
     * With type inference enabled, we may wipe out all JIT code on the
     * stack without patching ncode values to jump to the interpreter, and
     * thus can only enter JIT code via EnterMethodJIT (which overwrites
     * its entry frame's ncode). See ClearAllFrames.
     */
    cx->jaegerRuntime().setLastUnfinished(Jaeger_Unfinished);

    if (!JSScript::ensureRanAnalysis(cx, script)) {
        js_ReportOutOfMemory(cx);
        return NULL;
    }

    analyze::AutoEnterAnalysis enter(cx);

    /*
     * Interpret the ENTERBLOCK and EXCEPTION opcodes, so that we don't go
     * back into the interpreter with a pending exception. This will cause
     * it to immediately rethrow.
     */
    if (cx->isExceptionPending()) {
        JS_ASSERT(JSOp(*pc) == JSOP_ENTERBLOCK);
        StaticBlockObject &blockObj = script->getObject(GET_UINT32_INDEX(pc))->asStaticBlock();
        Value *vp = cx->regs().sp + blockObj.slotCount();
        SetValueRangeToUndefined(cx->regs().sp, vp);
        cx->regs().sp = vp;
        if (!cx->regs().fp()->pushBlock(cx, blockObj))
            return NULL;

        JS_ASSERT(JSOp(pc[JSOP_ENTERBLOCK_LENGTH]) == JSOP_EXCEPTION);
        cx->regs().sp[0] = cx->getPendingException();
        cx->clearPendingException();
        cx->regs().sp++;

        cx->regs().pc = pc + JSOP_ENTERBLOCK_LENGTH + JSOP_EXCEPTION_LENGTH;
    }

    *f.oldregs = f.regs;

    return NULL;
}

//.........这里部分代码省略.........

                switch (st) {
                case JSTRAP_ERROR:
                    cx->clearPendingException();
                    return NULL;

                case JSTRAP_CONTINUE:
                  break;

                case JSTRAP_RETURN:
                    cx->clearPendingException();
                    cx->fp()->setReturnValue(rval);
                    return cx->jaegerCompartment()->forceReturnFromExternC();

                case JSTRAP_THROW:
                    cx->setPendingException(rval);
                    break;

                default:
                    JS_NOT_REACHED("bad onExceptionUnwind status");
                }
            }
        }

        pc = FindExceptionHandler(cx);
        if (pc)
            break;

        // The JIT guarantees that ScriptEpilogue() has always been run
        // upon exiting to its caller. This is important for consistency,
        // where execution modes make similar guarantees about prologues
        // and epilogues. RunTracer(), Interpret(), and Invoke() all
        // rely on this property.
        JS_ASSERT(!f.fp()->finishedInInterpreter());
        UnwindScope(cx, 0, cx->isExceptionPending());

        if (cx->compartment->debugMode())
            js::ScriptDebugEpilogue(cx, f.fp(), false);

        ScriptEpilogue(f.cx, f.fp(), false);

        // Don't remove the last frame, this is the responsibility of
        // JaegerShot()'s caller. We only guarantee that ScriptEpilogue()
        // has been run.
        if (f.entryfp == f.fp())
            break;

        JS_ASSERT(f.regs.sp == cx->regs().sp);
        InlineReturn(f);
    }

    JS_ASSERT(f.regs.sp == cx->regs().sp);

    if (!pc)
        return NULL;

    StackFrame *fp = cx->fp();
    JSScript *script = fp->script();

    /*
     * Fall back to EnterMethodJIT and finish the frame in the interpreter.
     * With type inference enabled, we may wipe out all JIT code on the
     * stack without patching ncode values to jump to the interpreter, and
     * thus can only enter JIT code via EnterMethodJIT (which overwrites
     * its entry frame's ncode). See ClearAllFrames.
     */
    cx->compartment->jaegerCompartment()->setLastUnfinished(Jaeger_Unfinished);

    if (!script->ensureRanAnalysis(cx, NULL)) {
        js_ReportOutOfMemory(cx);
        return NULL;
    }

    analyze::AutoEnterAnalysis enter(cx);

    cx->regs().pc = pc;
    cx->regs().sp = fp->base() + script->analysis()->getCode(pc).stackDepth;

    /*
     * Interpret the ENTERBLOCK and EXCEPTION opcodes, so that we don't go
     * back into the interpreter with a pending exception. This will cause
     * it to immediately rethrow.
     */
    if (cx->isExceptionPending()) {
        JS_ASSERT(JSOp(*pc) == JSOP_ENTERBLOCK);
        JSObject *obj = script->getObject(GET_SLOTNO(pc));
        Value *vp = cx->regs().sp + OBJ_BLOCK_COUNT(cx, obj);
        SetValueRangeToUndefined(cx->regs().sp, vp);
        cx->regs().sp = vp;
        JS_ASSERT(JSOp(pc[JSOP_ENTERBLOCK_LENGTH]) == JSOP_EXCEPTION);
        cx->regs().sp[0] = cx->getPendingException();
        cx->clearPendingException();
        cx->regs().sp++;
        cx->regs().pc = pc + JSOP_ENTERBLOCK_LENGTH + JSOP_EXCEPTION_LENGTH;
    }

    *f.oldregs = f.regs;

    return NULL;
}