JavaScriptCore/API/JSBase.cpp

// -*- mode: c++; c-basic-offset: 4 -*-
/*
 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
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 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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#include "config.h"
#include "JSBase.h"

#include "APICast.h"
#include "completion.h"
#include <kjs/ExecState.h>
#include <kjs/InitializeThreading.h>
#include <kjs/interpreter.h>
#include <kjs/JSGlobalObject.h>
#include <kjs/JSLock.h>
#include <kjs/JSObject.h>

using namespace KJS;

JSValueRef JSEvaluateScript(JSContextRef ctx, JSStringRef script, JSObjectRef thisObject, JSStringRef sourceURL, int startingLineNumber, JSValueRef* exception)
{
    ExecState* exec = toJS(ctx);
    exec->globalData().heap->registerThread();
    JSLock lock(exec);

    JSObject* jsThisObject = toJS(thisObject);
    UString::Rep* scriptRep = toJS(script);
    UString::Rep* sourceURLRep = sourceURL ? toJS(sourceURL) : &UString::Rep::null;

    // Interpreter::evaluate sets "this" to the global object if it is NULL
    JSGlobalObject* globalObject = exec->dynamicGlobalObject();
    Completion completion = Interpreter::evaluate(globalObject->globalExec(), globalObject->globalScopeChain(), UString(sourceURLRep), startingLineNumber, UString(scriptRep), jsThisObject);

    if (completion.complType() == Throw) {
        if (exception)
            *exception = toRef(completion.value());
        return 0;
    }
    
    if (completion.value())
        return toRef(completion.value());
    
    // happens, for example, when the only statement is an empty (';') statement
    return toRef(jsUndefined());
}

bool JSCheckScriptSyntax(JSContextRef ctx, JSStringRef script, JSStringRef sourceURL, int startingLineNumber, JSValueRef* exception)
{
    ExecState* exec = toJS(ctx);
    exec->globalData().heap->registerThread();
    JSLock lock(exec);

    UString::Rep* scriptRep = toJS(script);
    UString::Rep* sourceURLRep = sourceURL ? toJS(sourceURL) : &UString::Rep::null;
    Completion completion = Interpreter::checkSyntax(exec->dynamicGlobalObject()->globalExec(), UString(sourceURLRep), startingLineNumber, UString(scriptRep));
    if (completion.complType() == Throw) {
        if (exception)
            *exception = toRef(completion.value());
        return false;
    }
    
    return true;
}

void JSGarbageCollect(JSContextRef ctx)
{
    // Unlikely, but it is legal to call JSGarbageCollect(0) before actually doing anything that would implicitly call initializeThreading().
    if (!ctx)
        initializeThreading();

    // When using a shared heap, clients need to call JSGarbageCollect(0) after releasing the last reference to the context to avoid
    // leaking protected objects. Because the function arguments were originally ignored, some clients may pass their released context here,
    // in which case there is a risk of crashing if another thread performs GC on the same heap in between.
    if (ctx) {
        ExecState* exec = toJS(ctx);
        JSGlobalData& globalData = exec->globalData();
        Heap* heap = globalData.heap;

        JSLock lock(globalData.isSharedInstance);

        if (!heap->isBusy())
            heap->collect();
    } else {
        JSLock lock(true);

        if (JSGlobalData::sharedInstanceExists()) {
            Heap* heap = JSGlobalData::sharedInstance().heap;
            if (!heap->isBusy())
                heap->collect();
        }
    }

    // FIXME: Perhaps we should trigger a second mark and sweep
    // once the garbage collector is done if this is called when
    // the collector is busy.
}