spidermonkey.c

一个很有名的浏览器

	JSCLASS_HAS_PRIVATE,
	JS_PropertyStub, JS_PropertyStub,
	unibar_get_property, unibar_set_property,
	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
};
static const JSClass statusbar_class = {
	"statusbar",
	JSCLASS_HAS_PRIVATE,
	JS_PropertyStub, JS_PropertyStub,
	unibar_get_property, unibar_set_property,
	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
};

enum unibar_prop { JSP_UNIBAR_VISIBLE };
static const JSPropertySpec unibar_props[] = {
	{ "visible",	JSP_UNIBAR_VISIBLE,	JSPROP_ENUMERATE },
	{ NULL }
};


static JSBool
unibar_get_property(JSContext *ctx, JSObject *obj, jsval id, jsval *vp)
{
	JSObject *parent = JS_GetParent(ctx, obj);
	struct view_state *vs = JS_GetPrivate(ctx, parent);
	struct document_view *doc_view = vs->doc_view;
	struct session_status *status = &doc_view->session->status;
	unsigned char *bar = JS_GetPrivate(ctx, obj);
	struct jsval_property prop;

	set_prop_undef(&prop);

	if (!JSVAL_IS_INT(id))
		return JS_TRUE;

	switch (JSVAL_TO_INT(id)) {
	case JSP_UNIBAR_VISIBLE:
#define unibar_fetch(bar) \
	set_prop_boolean(&prop, status->force_show_##bar##_bar >= 0 \
	          ? status->force_show_##bar##_bar \
	          : status->show_##bar##_bar)
		switch (*bar) {
		case 's':
			unibar_fetch(status);
			break;
		case 't':
			unibar_fetch(title);
			break;
		default:
			set_prop_boolean(&prop, 0);
			break;
		}
#undef unibar_fetch
		break;
	default:
		INTERNAL("Invalid ID %d in unibar_get_property().", JSVAL_TO_INT(id));
		return JS_TRUE;
	}

	value_to_jsval(ctx, vp, &prop);
	return JS_TRUE;
}

static JSBool
unibar_set_property(JSContext *ctx, JSObject *obj, jsval id, jsval *vp)
{
	JSObject *parent = JS_GetParent(ctx, obj);
	struct view_state *vs = JS_GetPrivate(ctx, parent);
	struct document_view *doc_view = vs->doc_view;
	struct session_status *status = &doc_view->session->status;
	unsigned char *bar = JS_GetPrivate(ctx, obj);
	union jsval_union v;

	if (!JSVAL_IS_INT(id))
		return JS_TRUE;

	switch (JSVAL_TO_INT(id)) {
	case JSP_UNIBAR_VISIBLE:
		jsval_to_value(ctx, vp, JSTYPE_BOOLEAN, &v);
#define unibar_set(bar) \
	status->force_show_##bar##_bar = v.boolean;
		switch (*bar) {
		case 's':
			unibar_set(status);
			break;
		case 't':
			unibar_set(title);
			break;
		default:
			v.boolean = 0;
			break;
		}
		register_bottom_half((void (*)(void*)) update_status, NULL);
#undef unibar_set
		break;
	default:
		INTERNAL("Invalid ID %d in unibar_set_property().", JSVAL_TO_INT(id));
		return JS_TRUE;
	}

	return JS_TRUE;
}


static JSBool navigator_get_property(JSContext *ctx, JSObject *obj, jsval id, jsval *vp);

static const JSClass navigator_class = {
	"navigator",
	JSCLASS_HAS_PRIVATE,
	JS_PropertyStub, JS_PropertyStub,
	navigator_get_property, JS_PropertyStub,
	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
};

enum navigator_prop {
	JSP_NAVIGATOR_APP_CODENAME,
	JSP_NAVIGATOR_APP_NAME,
	JSP_NAVIGATOR_APP_VERSION,
	JSP_NAVIGATOR_LANGUAGE,
	/* JSP_NAVIGATOR_MIME_TYPES, */
	JSP_NAVIGATOR_PLATFORM,
	/* JSP_NAVIGATOR_PLUGINS, */
	JSP_NAVIGATOR_USER_AGENT,
};
static const JSPropertySpec navigator_props[] = {
	{ "appCodeName",	JSP_NAVIGATOR_APP_CODENAME,	JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "appName",		JSP_NAVIGATOR_APP_NAME,		JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "appVersion",		JSP_NAVIGATOR_APP_VERSION,	JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "language",		JSP_NAVIGATOR_LANGUAGE,		JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "platform",		JSP_NAVIGATOR_PLATFORM,		JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "userAgent",		JSP_NAVIGATOR_USER_AGENT,	JSPROP_ENUMERATE | JSPROP_READONLY },
	{ NULL }
};


static JSBool
navigator_get_property(JSContext *ctx, JSObject *obj, jsval id, jsval *vp)
{
	struct jsval_property prop;

	set_prop_undef(&prop);

	if (!JSVAL_IS_INT(id))
		return JS_TRUE;

	switch (JSVAL_TO_INT(id)) {
	case JSP_NAVIGATOR_APP_CODENAME:
		set_prop_string(&prop, "Mozilla"); /* More like a constant nowadays. */
		break;
	case JSP_NAVIGATOR_APP_NAME:
		/* This evil hack makes the compatibility checking .indexOf()
		 * code find what it's looking for. */
		set_prop_string(&prop, "ELinks (roughly compatible with Netscape Navigator, Mozilla and Microsoft Internet Explorer)");
		break;
	case JSP_NAVIGATOR_APP_VERSION:
		set_prop_string(&prop, VERSION);
		break;
	case JSP_NAVIGATOR_LANGUAGE:
#ifdef ENABLE_NLS
		if (get_opt_bool("protocol.http.accept_ui_language"))
			set_prop_string(&prop, language_to_iso639(current_language));
		else
#endif
			set_prop_undef(&prop);
		break;
	case JSP_NAVIGATOR_PLATFORM:
		set_prop_string(&prop, system_name);
		break;
	case JSP_NAVIGATOR_USER_AGENT:
	{
		/* FIXME: Code duplication. */
		unsigned char *optstr = get_opt_str("protocol.http.user_agent");

		if (*optstr && strcmp(optstr, " ")) {
			unsigned char *ustr, ts[64] = "";
			static unsigned char custr[256];

			if (!list_empty(terminals)) {
				unsigned int tslen = 0;
				struct terminal *term = terminals.prev;

				ulongcat(ts, &tslen, term->width, 3, 0);
				ts[tslen++] = 'x';
				ulongcat(ts, &tslen, term->height, 3, 0);
			}
			ustr = subst_user_agent(optstr, VERSION_STRING, system_name, ts);

			if (ustr) {
				safe_strncpy(custr, ustr, 256);
				mem_free(ustr);
				set_prop_string(&prop, custr);
			} else{
				set_prop_undef(&prop);
			}
		}
	}
		break;
	default:
		INTERNAL("Invalid ID %d in navigator_get_property().", JSVAL_TO_INT(id));
		return JS_TRUE;
	}

	value_to_jsval(ctx, vp, &prop);
	return JS_TRUE;
}



/*** The ELinks interface */

static JSRuntime *jsrt;

static void
error_reporter(JSContext *ctx, const char *message, JSErrorReport *report)
{
	struct ecmascript_interpreter *interpreter = JS_GetContextPrivate(ctx);
	struct terminal *term;
	unsigned char *strict, *exception, *warning, *error;
	struct string msg;

	assert(interpreter && interpreter->vs && interpreter->vs->doc_view
	       && interpreter->vs->doc_view->session
	       && interpreter->vs->doc_view->session->tab);
	if_assert_failed goto reported;

	term = interpreter->vs->doc_view->session->tab->term;

#ifdef CONFIG_LEDS
	interpreter->vs->doc_view->session->status.ecmascript_led->value = 'J';
#endif

	if (!get_opt_bool("ecmascript.error_reporting")
	    || !init_string(&msg))
		goto reported;

	strict	  = JSREPORT_IS_STRICT(report->flags) ? " strict" : "";
	exception = JSREPORT_IS_EXCEPTION(report->flags) ? " exception" : "";
	warning   = JSREPORT_IS_WARNING(report->flags) ? " warning" : "";
	error	  = !report->flags ? " error" : "";

	add_format_to_string(&msg, _("A script embedded in the current "
			"document raised the following%s%s%s%s", term),
			strict, exception, warning, error);

	add_to_string(&msg, ":\n\n");
	add_to_string(&msg, message);

	if (report->linebuf && report->tokenptr) {
		int pos = report->tokenptr - report->linebuf;

		add_format_to_string(&msg, "\n\n%s\n.%*s^%*s.",
			       report->linebuf,
			       pos - 2, " ",
			       strlen(report->linebuf) - pos - 1, " ");
	}

	info_box(term, MSGBOX_FREE_TEXT, N_("JavaScript Error"), ALIGN_CENTER,
		 msg.source);

reported:
	/* Im clu'les. --pasky */
	JS_ClearPendingException(ctx);
}

static JSBool
safeguard(JSContext *ctx, JSScript *script)
{
	struct ecmascript_interpreter *interpreter = JS_GetContextPrivate(ctx);
	int max_exec_time = get_opt_int("ecmascript.max_exec_time");

	if (time(NULL) - interpreter->exec_start > max_exec_time) {
		struct terminal *term = interpreter->vs->doc_view->session->tab->term;

		/* A killer script! Alert! */
		info_box(term, MSGBOX_FREE_TEXT,
			 N_("JavaScript Emergency"), ALIGN_LEFT,
			 msg_text(term,
				  N_("A script embedded in the current document was running\n"
				  "for more than %d seconds. This probably means there is\n"
				  "a bug in the script and it could have halted the whole\n"
				  "ELinks, so the script execution was interrupted."),
				  max_exec_time));
		return JS_FALSE;
	}
	return JS_TRUE;
}

static void
setup_safeguard(struct ecmascript_interpreter *interpreter,
                JSContext *ctx)
{
	interpreter->exec_start = time(NULL);
	JS_SetBranchCallback(ctx, safeguard);
}


void
spidermonkey_init(void)
{
	jsrt = JS_NewRuntime(0x400000UL);
}

void
spidermonkey_done(void)
{
	JS_DestroyRuntime(jsrt);
	JS_ShutDown();
}


void *
spidermonkey_get_interpreter(struct ecmascript_interpreter *interpreter)
{
	JSContext *ctx;
	JSObject *window_obj, *document_obj, *forms_obj, *location_obj,
	         *statusbar_obj, *menubar_obj, *navigator_obj;

	assert(interpreter);

	ctx = JS_NewContext(jsrt, 8192 /* Stack allocation chunk size */);
	if (!ctx)
		return NULL;
	interpreter->backend_data = ctx;
	JS_SetContextPrivate(ctx, interpreter);
	/* TODO: Make JSOPTION_STRICT and JSOPTION_WERROR configurable. */
#ifndef JSOPTION_COMPILE_N_GO
#define JSOPTION_COMPILE_N_GO 0 /* Older SM versions don't have it. */
#endif
	/* XXX: JSOPTION_COMPILE_N_GO will go (will it?) when we implement
	 * some kind of bytecode cache. (If we will ever do that.) */
	JS_SetOptions(ctx, JSOPTION_VAROBJFIX | JSOPTION_COMPILE_N_GO);
	JS_SetErrorReporter(ctx, error_reporter);

	window_obj = JS_NewObject(ctx, (JSClass *) &window_class, NULL, NULL);
	if (!window_obj) {
		spidermonkey_put_interpreter(interpreter);
		return NULL;
	}
	JS_InitStandardClasses(ctx, window_obj);
	JS_DefineProperties(ctx, window_obj, (JSPropertySpec *) window_props);
	JS_DefineFunctions(ctx, window_obj, (JSFunctionSpec *) window_funcs);
	JS_SetPrivate(ctx, window_obj, interpreter->vs);

	document_obj = JS_InitClass(ctx, window_obj, NULL,
				    (JSClass *) &document_class, NULL, 0,
				    (JSPropertySpec *) document_props,
				    (JSFunctionSpec *) document_funcs,
				    NULL, NULL);

	forms_obj = JS_InitClass(ctx, document_obj, NULL,
				    (JSClass *) &forms_class, NULL, 0,
				    (JSPropertySpec *) forms_props,
				    (JSFunctionSpec *) forms_funcs,
				    NULL, NULL);

	location_obj = JS_InitClass(ctx, window_obj, NULL,
				    (JSClass *) &location_class, NULL, 0,
				    (JSPropertySpec *) location_props,
				    (JSFunctionSpec *) location_funcs,
				    NULL, NULL);

	menubar_obj = JS_InitClass(ctx, window_obj, NULL,
				   (JSClass *) &menubar_class, NULL, 0,
				   (JSPropertySpec *) unibar_props, NULL,
				   NULL, NULL);
	JS_SetPrivate(ctx, menubar_obj, "t");

	statusbar_obj = JS_InitClass(ctx, window_obj, NULL,
				     (JSClass *) &statusbar_class, NULL, 0,
				     (JSPropertySpec *) unibar_props, NULL,
				     NULL, NULL);
	JS_SetPrivate(ctx, statusbar_obj, "s");

	navigator_obj = JS_InitClass(ctx, window_obj, NULL,
				     (JSClass *) &navigator_class, NULL, 0,
				     (JSPropertySpec *) navigator_props, NULL,
				     NULL, NULL);

	return ctx;
}

void
spidermonkey_put_interpreter(struct ecmascript_interpreter *interpreter)
{
	JSContext *ctx;

	assert(interpreter);
	ctx = interpreter->backend_data;
	JS_DestroyContext(ctx);
	interpreter->backend_data = NULL;
}


void
spidermonkey_eval(struct ecmascript_interpreter *interpreter,
                  struct string *code)
{
	JSContext *ctx;
	jsval rval;

	assert(interpreter);
	ctx = interpreter->backend_data;
	setup_safeguard(interpreter, ctx);
	JS_EvaluateScript(ctx, JS_GetGlobalObject(ctx),
	                  code->source, code->length, "", 0, &rval);
}


unsigned char *
spidermonkey_eval_stringback(struct ecmascript_interpreter *interpreter,
			     struct string *code)
{
	JSContext *ctx;
	jsval rval;
	union jsval_union v;

	assert(interpreter);
	ctx = interpreter->backend_data;
	setup_safeguard(interpreter, ctx);
	if (JS_EvaluateScript(ctx, JS_GetGlobalObject(ctx),
			      code->source, code->length, "", 0, &rval)
	    == JS_FALSE) {
		return NULL;
	}
	if (JSVAL_IS_VOID(rval)) {
		/* Undefined value. */
		return NULL;
	}

	jsval_to_value(ctx, &rval, JSTYPE_STRING, &v);
	if (!v.string) return NULL;

	return stracpy(v.string);
}


int
spidermonkey_eval_boolback(struct ecmascript_interpreter *interpreter,
			   struct string *code)
{
	JSContext *ctx;
	jsval rval;
	union jsval_union v;

	assert(interpreter);
	ctx = interpreter->backend_data;
	setup_safeguard(interpreter, ctx);
	if (JS_EvaluateScript(ctx, JS_GetGlobalObject(ctx),
			      code->source, code->length, "", 0, &rval)
	    == JS_FALSE) {
		return -1;
	}
	if (JSVAL_IS_VOID(rval)) {
		/* Undefined value. */
		return -1;
	}

	jsval_to_value(ctx, &rval, JSTYPE_BOOLEAN, &v);
	return v.boolean;
}