jscntxt.c

来自「java script test programing source code」· C语言 代码 · 共 1,230 行 · 第 1/3 页

{
    /*
     * Check the error report, and set a JavaScript-catchable exception
     * if the error is defined to have an associated exception.  If an
     * exception is thrown, then the JSREPORT_EXCEPTION flag will be set
     * on the error report, and exception-aware hosts should ignore it.
     */
    JS_ASSERT(reportp);
    if (reportp->errorNumber == JSMSG_UNCAUGHT_EXCEPTION)
        reportp->flags |= JSREPORT_EXCEPTION;

    /*
     * Call the error reporter only if an exception wasn't raised.
     *
     * If an exception was raised, then we call the debugErrorHook
     * (if present) to give it a chance to see the error before it
     * propagates out of scope.  This is needed for compatability
     * with the old scheme.
     */
    if (!js_ErrorToException(cx, message, reportp)) {
        js_ReportErrorAgain(cx, message, reportp);
    } else if (cx->runtime->debugErrorHook && cx->errorReporter) {
        JSDebugErrorHook hook = cx->runtime->debugErrorHook;
        /* test local in case debugErrorHook changed on another thread */
        if (hook)
            hook(cx, message, reportp, cx->runtime->debugErrorHookData);
    }
}

/*
 * We don't post an exception in this case, since doing so runs into
 * complications of pre-allocating an exception object which required
 * running the Exception class initializer early etc.
 * Instead we just invoke the errorReporter with an "Out Of Memory"
 * type message, and then hope the process ends swiftly.
 */
void
js_ReportOutOfMemory(JSContext *cx)
{
    JSStackFrame *fp;
    JSErrorReport report;
    JSErrorReporter onError = cx->errorReporter;

    /* Get the message for this error, but we won't expand any arguments. */
    const JSErrorFormatString *efs =
        js_GetLocalizedErrorMessage(cx, NULL, NULL, JSMSG_OUT_OF_MEMORY);
    const char *msg = efs ? efs->format : "Out of memory";

    /* Fill out the report, but don't do anything that requires allocation. */
    memset(&report, 0, sizeof (struct JSErrorReport));
    report.flags = JSREPORT_ERROR;
    report.errorNumber = JSMSG_OUT_OF_MEMORY;

    /*
     * Walk stack until we find a frame that is associated with some script
     * rather than a native frame.
     */
    for (fp = cx->fp; fp; fp = fp->down) {
        if (fp->script && fp->pc) {
            report.filename = fp->script->filename;
            report.lineno = js_PCToLineNumber(cx, fp->script, fp->pc);
            break;
        }
    }

    /*
     * If debugErrorHook is present then we give it a chance to veto
     * sending the error on to the regular ErrorReporter.
     */
    if (onError) {
        JSDebugErrorHook hook = cx->runtime->debugErrorHook;
        if (hook &&
            !hook(cx, msg, &report, cx->runtime->debugErrorHookData)) {
            onError = NULL;
        }
    }

    if (onError)
        onError(cx, msg, &report);
}

JSBool
js_ReportErrorVA(JSContext *cx, uintN flags, const char *format, va_list ap)
{
    char *message;
    jschar *ucmessage;
    size_t messagelen;
    JSStackFrame *fp;
    JSErrorReport report;
    JSBool warning;

    if ((flags & JSREPORT_STRICT) && !JS_HAS_STRICT_OPTION(cx))
        return JS_TRUE;

    message = JS_vsmprintf(format, ap);
    if (!message)
        return JS_FALSE;
    messagelen = strlen(message);

    memset(&report, 0, sizeof (struct JSErrorReport));
    report.flags = flags;
    report.errorNumber = JSMSG_USER_DEFINED_ERROR;
    report.ucmessage = ucmessage = js_InflateString(cx, message, &messagelen);

    /* Find the top-most active script frame, for best line number blame. */
    for (fp = cx->fp; fp; fp = fp->down) {
        if (fp->script && fp->pc) {
            report.filename = fp->script->filename;
            report.lineno = js_PCToLineNumber(cx, fp->script, fp->pc);
            break;
        }
    }

    warning = JSREPORT_IS_WARNING(report.flags);
    if (warning && JS_HAS_WERROR_OPTION(cx)) {
        report.flags &= ~JSREPORT_WARNING;
        warning = JS_FALSE;
    }

    ReportError(cx, message, &report);
    free(message);
    JS_free(cx, ucmessage);
    return warning;
}

/*
 * The arguments from ap need to be packaged up into an array and stored
 * into the report struct.
 *
 * The format string addressed by the error number may contain operands
 * identified by the format {N}, where N is a decimal digit. Each of these
 * is to be replaced by the Nth argument from the va_list. The complete
 * message is placed into reportp->ucmessage converted to a JSString.
 *
 * Returns true if the expansion succeeds (can fail if out of memory).
 */
JSBool
js_ExpandErrorArguments(JSContext *cx, JSErrorCallback callback,
                        void *userRef, const uintN errorNumber,
                        char **messagep, JSErrorReport *reportp,
                        JSBool *warningp, JSBool charArgs, va_list ap)
{
    const JSErrorFormatString *efs;
    int i;
    int argCount;

    *warningp = JSREPORT_IS_WARNING(reportp->flags);
    if (*warningp && JS_HAS_WERROR_OPTION(cx)) {
        reportp->flags &= ~JSREPORT_WARNING;
        *warningp = JS_FALSE;
    }

    *messagep = NULL;

    /* Most calls supply js_GetErrorMessage; if this is so, assume NULL. */
    if (!callback || callback == js_GetErrorMessage)
        efs = js_GetLocalizedErrorMessage(cx, userRef, NULL, errorNumber);
    else
        efs = callback(userRef, NULL, errorNumber);
    if (efs) {
        size_t totalArgsLength = 0;
        size_t argLengths[10]; /* only {0} thru {9} supported */
        argCount = efs->argCount;
        JS_ASSERT(argCount <= 10);
        if (argCount > 0) {
            /*
             * Gather the arguments into an array, and accumulate
             * their sizes. We allocate 1 more than necessary and
             * null it out to act as the caboose when we free the
             * pointers later.
             */
            reportp->messageArgs = (const jschar **)
                JS_malloc(cx, sizeof(jschar *) * (argCount + 1));
            if (!reportp->messageArgs)
                return JS_FALSE;
            reportp->messageArgs[argCount] = NULL;
            for (i = 0; i < argCount; i++) {
                if (charArgs) {
                    char *charArg = va_arg(ap, char *);
                    size_t charArgLength = strlen(charArg);
                    reportp->messageArgs[i]
                        = js_InflateString(cx, charArg, &charArgLength);
                    if (!reportp->messageArgs[i])
                        goto error;
                } else {
                    reportp->messageArgs[i] = va_arg(ap, jschar *);
                }
                argLengths[i] = js_strlen(reportp->messageArgs[i]);
                totalArgsLength += argLengths[i];
            }
            /* NULL-terminate for easy copying. */
            reportp->messageArgs[i] = NULL;
        }
        /*
         * Parse the error format, substituting the argument X
         * for {X} in the format.
         */
        if (argCount > 0) {
            if (efs->format) {
                jschar *buffer, *fmt, *out;
                int expandedArgs = 0;
                size_t expandedLength;
                size_t len = strlen(efs->format);

                buffer = fmt = js_InflateString (cx, efs->format, &len);
                if (!buffer)
                    goto error;
                expandedLength = len
                                 - (3 * argCount)       /* exclude the {n} */
                                 + totalArgsLength;

                /*
                * Note - the above calculation assumes that each argument
                * is used once and only once in the expansion !!!
                */
                reportp->ucmessage = out = (jschar *)
                    JS_malloc(cx, (expandedLength + 1) * sizeof(jschar));
                if (!out) {
                    JS_free (cx, buffer);
                    goto error;
                }
                while (*fmt) {
                    if (*fmt == '{') {
                        if (isdigit(fmt[1])) {
                            int d = JS7_UNDEC(fmt[1]);
                            JS_ASSERT(d < argCount);
                            js_strncpy(out, reportp->messageArgs[d],
                                       argLengths[d]);
                            out += argLengths[d];
                            fmt += 3;
                            expandedArgs++;
                            continue;
                        }
                    }
                    *out++ = *fmt++;
                }
                JS_ASSERT(expandedArgs == argCount);
                *out = 0;
                JS_free (cx, buffer);
                *messagep =
                    js_DeflateString(cx, reportp->ucmessage,
                                     (size_t)(out - reportp->ucmessage));
                if (!*messagep)
                    goto error;
            }
        } else {
            /*
             * Zero arguments: the format string (if it exists) is the
             * entire message.
             */
            if (efs->format) {
                size_t len;
                *messagep = JS_strdup(cx, efs->format);
                if (!*messagep)
                    goto error;
                len = strlen(*messagep);
                reportp->ucmessage = js_InflateString(cx, *messagep, &len);
                if (!reportp->ucmessage)
                    goto error;
            }
        }
    }
    if (*messagep == NULL) {
        /* where's the right place for this ??? */
        const char *defaultErrorMessage
            = "No error message available for error number %d";
        size_t nbytes = strlen(defaultErrorMessage) + 16;
        *messagep = (char *)JS_malloc(cx, nbytes);
        if (!*messagep)
            goto error;
        JS_snprintf(*messagep, nbytes, defaultErrorMessage, errorNumber);
    }
    return JS_TRUE;

error:
    if (reportp->messageArgs) {
        /* free the arguments only if we allocated them */
        if (charArgs) {
            i = 0;
            while (reportp->messageArgs[i])
                JS_free(cx, (void *)reportp->messageArgs[i++]);
        }
        JS_free(cx, (void *)reportp->messageArgs);
        reportp->messageArgs = NULL;
    }
    if (reportp->ucmessage) {
        JS_free(cx, (void *)reportp->ucmessage);
        reportp->ucmessage = NULL;
    }
    if (*messagep) {
        JS_free(cx, (void *)*messagep);
        *messagep = NULL;
    }
    return JS_FALSE;
}

JSBool
js_ReportErrorNumberVA(JSContext *cx, uintN flags, JSErrorCallback callback,
                       void *userRef, const uintN errorNumber,
                       JSBool charArgs, va_list ap)
{
    JSStackFrame *fp;
    JSErrorReport report;
    char *message;
    JSBool warning;

    if ((flags & JSREPORT_STRICT) && !JS_HAS_STRICT_OPTION(cx))
        return JS_TRUE;

    memset(&report, 0, sizeof (struct JSErrorReport));
    report.flags = flags;
    report.errorNumber = errorNumber;

    /*
     * If we can't find out where the error was based on the current frame,
     * see if the next frame has a script/pc combo we can use.
     */
    for (fp = cx->fp; fp; fp = fp->down) {
        if (fp->script && fp->pc) {
            report.filename = fp->script->filename;
            report.lineno = js_PCToLineNumber(cx, fp->script, fp->pc);
            break;
        }
    }

    if (!js_ExpandErrorArguments(cx, callback, userRef, errorNumber,
                                 &message, &report, &warning, charArgs, ap)) {
        return JS_FALSE;
    }

    ReportError(cx, message, &report);

    if (message)
        JS_free(cx, message);
    if (report.messageArgs) {
        /*
         * js_ExpandErrorArguments owns its messageArgs only if it had to
         * inflate the arguments (from regular |char *|s).
         */
        if (charArgs) {
            int i = 0;
            while (report.messageArgs[i])
                JS_free(cx, (void *)report.messageArgs[i++]);
        }
        JS_free(cx, (void *)report.messageArgs);
    }
    if (report.ucmessage)
        JS_free(cx, (void *)report.ucmessage);

    return warning;
}

JS_FRIEND_API(void)
js_ReportErrorAgain(JSContext *cx, const char *message, JSErrorReport *reportp)
{
    JSErrorReporter onError;

    if (!message)
        return;

    if (cx->lastMessage)
        free(cx->lastMessage);
    cx->lastMessage = JS_strdup(cx, message);
    if (!cx->lastMessage)
        return;
    onError = cx->errorReporter;

    /*
     * If debugErrorHook is present then we give it a chance to veto
     * sending the error on to the regular ErrorReporter.
     */
    if (onError) {
        JSDebugErrorHook hook = cx->runtime->debugErrorHook;
        if (hook &&
            !hook(cx, cx->lastMessage, reportp,
                  cx->runtime->debugErrorHookData)) {
            onError = NULL;
        }
    }
    if (onError)
        onError(cx, cx->lastMessage, reportp);
}

void
js_ReportIsNotDefined(JSContext *cx, const char *name)
{
    JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_NOT_DEFINED, name);
}

#if defined DEBUG && defined XP_UNIX
/* For gdb usage. */
void js_traceon(JSContext *cx)  { cx->tracefp = stderr; }
void js_traceoff(JSContext *cx) { cx->tracefp = NULL; }
#endif

JSErrorFormatString js_ErrorFormatString[JSErr_Limit] = {
#define MSG_DEF(name, number, count, exception, format) \
    { format, count, exception } ,
#include "js.msg"
#undef MSG_DEF
};

const JSErrorFormatString *
js_GetErrorMessage(void *userRef, const char *locale, const uintN errorNumber)
{
    if ((errorNumber > 0) && (errorNumber < JSErr_Limit))
        return &js_ErrorFormatString[errorNumber];
    return NULL;
}