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#include <JavaScriptCore/JavaScript.h>
#include "js_shell.h"
#include <iostream>
#include <stdio.h>
#ifdef __GNUC__
#include <dlfcn.h>
#define LOAD_SYMBOL(handle, name) dlsym(handle, name)
#else
#error "implement dll loading"
#endif
class JSCShell: public JSShell {
typedef int (*JSCIntializer)(JSGlobalContextRef context, JSObjectRef *module);
public:
JSCShell() {};
virtual ~JSCShell();
protected:
virtual bool InitializeEngine();
virtual bool ExecuteScript(const std::string& source, const std::string& scriptPath);
virtual bool DisposeEngine();
private:
JSObjectRef Import(const std::string &moduleName);
static JSValueRef Print(JSContextRef context, JSObjectRef object, JSObjectRef globalobj, size_t argc, const JSValueRef args[], JSValueRef* ex);
static JSValueRef Require(JSContextRef context, JSObjectRef object, JSObjectRef globalobj, size_t argc, const JSValueRef args[], JSValueRef* ex);
static bool RegisterFunction(JSGlobalContextRef context, JSObjectRef object, const char* functionName, JSObjectCallAsFunctionCallback cbFunction);
static void PrintError(JSContextRef, JSValueRef);
private:
JSGlobalContextRef context;
};
JSCShell::~JSCShell() {
if(context != 0) {
JSGlobalContextRelease(context);
context = 0;
}
}
bool JSCShell::InitializeEngine() {
if(context != 0) {
JSGlobalContextRelease(context);
context = 0;
}
// TODO: check for initialization errors
context = JSGlobalContextCreate(NULL);
if(context == 0) return false;
JSObjectRef globalObject = JSContextGetGlobalObject(context);
// store this for later use
JSClassDefinition __shell_classdef__ = JSClassDefinition();
JSClassRef __shell_class__ = JSClassCreate(&__shell_classdef__);
JSObjectRef __shell__ = JSObjectMake(context, __shell_class__, 0);
bool success = JSObjectSetPrivate(__shell__, (void*) (long) this);
if (!success) {
std::cerr << "Could not register the shell in the Javascript context" << std::endl;
return false;
}
JSStringRef shellKey = JSStringCreateWithUTF8CString("__shell__");
JSObjectSetProperty(context, globalObject, shellKey, __shell__, kJSPropertyAttributeReadOnly, NULL);
JSStringRelease(shellKey);
JSCShell::RegisterFunction(context, globalObject, "print", JSCShell::Print);
JSCShell::RegisterFunction(context, globalObject, "require", JSCShell::Require);
return true;
}
bool JSCShell::ExecuteScript(const std::string& source, const std::string& scriptPath) {
JSStringRef jsScript;
JSStringRef sourceURL;
JSValueRef ex;
jsScript = JSStringCreateWithUTF8CString(source.c_str());
sourceURL = JSStringCreateWithUTF8CString(scriptPath.c_str());
JSValueRef jsResult = JSEvaluateScript(context, jsScript, 0, sourceURL, 0, &ex);
JSStringRelease(jsScript);
if (jsResult == NULL && ex != NULL) {
JSCShell::PrintError(context, ex);
return false;
}
return true;
}
bool JSCShell::DisposeEngine() {
JSGlobalContextRelease(context);
context = 0;
return true;
}
JSValueRef JSCShell::Print(JSContextRef context, JSObjectRef object,
JSObjectRef globalobj, size_t argc,
const JSValueRef args[], JSValueRef* ex) {
if (argc > 0)
{
JSStringRef string = JSValueToStringCopy(context, args[0], NULL);
size_t numChars = JSStringGetMaximumUTF8CStringSize(string);
char *stringUTF8 = new char[numChars];
JSStringGetUTF8CString(string, stringUTF8, numChars);
printf("%s\n", stringUTF8);
delete[] stringUTF8;
}
return JSValueMakeUndefined(context);
}
// Attention: this feature should not create too high expectations.
// It is only capable of loading things relative to the execution directory
// and not relative to the parent script.
JSValueRef JSCShell::Require(JSContextRef context, JSObjectRef object,
JSObjectRef globalObj, size_t argc,
const JSValueRef args[], JSValueRef* ex) {
JSObjectRef module;
JSStringRef shellKey = JSStringCreateWithUTF8CString("__shell__");
JSValueRef shellAsVal = JSObjectGetProperty(context, globalObj, shellKey, NULL);
JSStringRelease(shellKey);
JSObjectRef shell = JSValueToObject(context, shellAsVal, 0);
JSCShell *_this = (JSCShell*) (long) JSObjectGetPrivate(shell);
if (argc > 0)
{
JSStringRef string = JSValueToStringCopy(context, args[0], NULL);
size_t numChars = JSStringGetMaximumUTF8CStringSize(string);
char *stringUTF8 = new char[numChars];
JSStringGetUTF8CString(string, stringUTF8, numChars);
std::string modulePath(stringUTF8);
module = _this->Import(modulePath);
delete[] stringUTF8;
}
if (module) {
return module;
} else {
printf("Ooops.\n");
return JSValueMakeUndefined(context);
}
}
JSObjectRef JSCShell::Import(const std::string& module_path) {
HANDLE library;
std::string module_name = LoadModule(module_path, &library);
if (library == 0) {
printf("Could not load module.");
return 0;
}
std::string symname = std::string(module_name).append("_initialize");
JSCIntializer init_function = reinterpret_cast<JSCIntializer>((long) LOAD_SYMBOL(library, symname.c_str()));
if(init_function == 0) {
printf("Could not find module's initializer function.");
return 0;
}
JSObjectRef module;
init_function(context, &module);
return module;
}
bool JSCShell::RegisterFunction(JSGlobalContextRef context, JSObjectRef object,
const char* functionName, JSObjectCallAsFunctionCallback callback) {
JSStringRef js_functionName = JSStringCreateWithUTF8CString(functionName);
JSObjectSetProperty(context, object, js_functionName,
JSObjectMakeFunctionWithCallback(context, js_functionName, callback),
kJSPropertyAttributeNone, NULL);
JSStringRelease(js_functionName);
return true;
}
void JSCShell::PrintError(JSContextRef ctx, JSValueRef err) {
char *buffer;
size_t length;
JSStringRef string = JSValueToStringCopy(ctx, err, 0);
length = JSStringGetLength(string);
buffer = new char[length+1];
JSStringGetUTF8CString(string, buffer, length+1);
std::string errMsg(buffer);
JSStringRelease(string);
delete[] buffer;
JSObjectRef errObj = JSValueToObject(ctx, err, 0);
if(errObj == 0) {
std::cerr << errMsg << std::endl;
return;
}
JSStringRef sourceURLKey = JSStringCreateWithUTF8CString("sourceURL");
JSStringRef sourceURLStr = JSValueToStringCopy(ctx, JSObjectGetProperty(ctx, errObj, sourceURLKey, 0), 0);
length = JSStringGetLength(sourceURLStr);
buffer = new char[length+1];
JSStringGetUTF8CString(sourceURLStr, buffer, length+1);
std::string sourceURL(buffer);
delete[] buffer;
JSStringRelease(sourceURLStr);
JSStringRelease(sourceURLKey);
JSStringRef lineKey = JSStringCreateWithUTF8CString("line");
JSValueRef jsLine = JSObjectGetProperty(ctx, errObj, lineKey, 0);
int line = (int) JSValueToNumber(ctx, jsLine, 0);
JSStringRelease(lineKey);
std::cerr << sourceURL << ":" << line << ":" << errMsg << std::endl;
}
JSShell* JSCShell_Create() {
return new JSCShell();
}
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