jsexn.c

java script test programing source code

            JSObject **objp)
{
    JSExnPrivate *priv;
    JSString *str;
    JSAtom *atom;
    JSString *stack;
    const char *prop;
    jsval v;

    *objp = NULL;
    priv = GetExnPrivate(cx, obj);
    if (priv && JSVAL_IS_STRING(id)) {
        str = JSVAL_TO_STRING(id);

        atom = cx->runtime->atomState.messageAtom;
        if (str == ATOM_TO_STRING(atom)) {
            prop = js_message_str;
            v = STRING_TO_JSVAL(priv->message);
            goto define;
        }

        atom = cx->runtime->atomState.fileNameAtom;
        if (str == ATOM_TO_STRING(atom)) {
            prop = js_fileName_str;
            v = STRING_TO_JSVAL(priv->filename);
            goto define;
        }

        atom = cx->runtime->atomState.lineNumberAtom;
        if (str == ATOM_TO_STRING(atom)) {
            prop = js_lineNumber_str;
            v = INT_TO_JSVAL(priv->lineno);
            goto define;
        }

        atom = cx->runtime->atomState.stackAtom;
        if (str == ATOM_TO_STRING(atom)) {
            stack = StackTraceToString(cx, priv);
            if (!stack)
                return JS_FALSE;

            /* Allow to GC all things that were used to build stack trace. */
            priv->stackDepth = 0;
            prop = js_stack_str;
            v = STRING_TO_JSVAL(stack);
            goto define;
        }
    }
    return JS_TRUE;

  define:
    if (!JS_DefineProperty(cx, obj, prop, v, NULL, NULL, JSPROP_ENUMERATE))
        return JS_FALSE;
    *objp = obj;
    return JS_TRUE;
}

JSErrorReport *
js_ErrorFromException(JSContext *cx, jsval exn)
{
    JSObject *obj;
    JSExnPrivate *priv;

    if (JSVAL_IS_PRIMITIVE(exn))
        return NULL;
    obj = JSVAL_TO_OBJECT(exn);
    if (OBJ_GET_CLASS(cx, obj) != &js_ErrorClass)
        return NULL;
    priv = GetExnPrivate(cx, obj);
    if (!priv)
        return NULL;
    return priv->errorReport;
}

struct JSExnSpec {
    int protoIndex;
    const char *name;
    JSProtoKey key;
    JSNative native;
};

/*
 * All *Error constructors share the same JSClass, js_ErrorClass.  But each
 * constructor function for an *Error class must have a distinct native 'call'
 * function pointer, in order for instanceof to work properly across multiple
 * standard class sets.  See jsfun.c:fun_hasInstance.
 */
#define MAKE_EXCEPTION_CTOR(name)                                             \
static JSBool                                                                 \
name(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)      \
{                                                                             \
    return Exception(cx, obj, argc, argv, rval);                              \
}

MAKE_EXCEPTION_CTOR(Error)
MAKE_EXCEPTION_CTOR(InternalError)
MAKE_EXCEPTION_CTOR(EvalError)
MAKE_EXCEPTION_CTOR(RangeError)
MAKE_EXCEPTION_CTOR(ReferenceError)
MAKE_EXCEPTION_CTOR(SyntaxError)
MAKE_EXCEPTION_CTOR(TypeError)
MAKE_EXCEPTION_CTOR(URIError)

#undef MAKE_EXCEPTION_CTOR

static struct JSExnSpec exceptions[] = {
    {JSEXN_NONE, js_Error_str,          JSProto_Error,          Error},
    {JSEXN_ERR,  js_InternalError_str,  JSProto_InternalError,  InternalError},
    {JSEXN_ERR,  js_EvalError_str,      JSProto_EvalError,      EvalError},
    {JSEXN_ERR,  js_RangeError_str,     JSProto_RangeError,     RangeError},
    {JSEXN_ERR,  js_ReferenceError_str, JSProto_ReferenceError, ReferenceError},
    {JSEXN_ERR,  js_SyntaxError_str,    JSProto_SyntaxError,    SyntaxError},
    {JSEXN_ERR,  js_TypeError_str,      JSProto_TypeError,      TypeError},
    {JSEXN_ERR,  js_URIError_str,       JSProto_URIError,       URIError},
    {0,          NULL,                  JSProto_Null,           NULL}
};

static JSString *
ValueToShortSource(JSContext *cx, jsval v)
{
    JSString *str;

    /* Avoid toSource bloat and fallibility for object types. */
    if (JSVAL_IS_PRIMITIVE(v)) {
        str = js_ValueToSource(cx, v);
    } else if (VALUE_IS_FUNCTION(cx, v)) {
        /*
         * XXX Avoid function decompilation bloat for now.
         */
        str = JS_GetFunctionId(JS_ValueToFunction(cx, v));
        if (!str && !(str = js_ValueToSource(cx, v))) {
            /*
             * Continue to soldier on if the function couldn't be
             * converted into a string.
             */
            JS_ClearPendingException(cx);
            str = JS_NewStringCopyZ(cx, "[unknown function]");
        }
    } else {
        /*
         * XXX Avoid toString on objects, it takes too long and uses too much
         * memory, for too many classes (see Mozilla bug 166743).
         */
        char buf[100];
        JS_snprintf(buf, sizeof buf, "[object %s]",
                    OBJ_GET_CLASS(cx, JSVAL_TO_OBJECT(v))->name);
        str = JS_NewStringCopyZ(cx, buf);
    }
    return str;
}

static JSString *
StackTraceToString(JSContext *cx, JSExnPrivate *priv)
{
    jschar *stackbuf;
    size_t stacklen, stackmax;
    JSStackTraceElem *elem, *endElem;
    jsval *values;
    size_t i;
    JSString *str;
    const char *cp;
    char ulnbuf[11];

    /* After this point, failing control flow must goto bad. */
    stackbuf = NULL;
    stacklen = stackmax = 0;

/* Limit the stackbuf length to a reasonable value to avoid overflow checks. */
#define STACK_LENGTH_LIMIT JS_BIT(20)

#define APPEND_CHAR_TO_STACK(c)                                               \
    JS_BEGIN_MACRO                                                            \
        if (stacklen == stackmax) {                                           \
            void *ptr_;                                                       \
            if (stackmax >= STACK_LENGTH_LIMIT)                               \
                goto done;                                                    \
            stackmax = stackmax ? 2 * stackmax : 64;                          \
            ptr_ = JS_realloc(cx, stackbuf, (stackmax+1) * sizeof(jschar));   \
            if (!ptr_)                                                        \
                goto bad;                                                     \
            stackbuf = ptr_;                                                  \
        }                                                                     \
        stackbuf[stacklen++] = (c);                                           \
    JS_END_MACRO

#define APPEND_STRING_TO_STACK(str)                                           \
    JS_BEGIN_MACRO                                                            \
        JSString *str_ = str;                                                 \
        size_t length_ = JSSTRING_LENGTH(str_);                               \
        if (length_ > stackmax - stacklen) {                                  \
            void *ptr_;                                                       \
            if (stackmax >= STACK_LENGTH_LIMIT ||                             \
                length_ >= STACK_LENGTH_LIMIT - stacklen) {                   \
                goto done;                                                    \
            }                                                                 \
            stackmax = JS_BIT(JS_CeilingLog2(stacklen + length_));            \
            ptr_ = JS_realloc(cx, stackbuf, (stackmax+1) * sizeof(jschar));   \
            if (!ptr_)                                                        \
                goto bad;                                                     \
            stackbuf = ptr_;                                                  \
        }                                                                     \
        js_strncpy(stackbuf + stacklen, JSSTRING_CHARS(str_), length_);       \
        stacklen += length_;                                                  \
    JS_END_MACRO

    values = GetStackTraceValueBuffer(priv);
    elem = priv->stackElems;
    for (endElem = elem + priv->stackDepth; elem != endElem; elem++) {
        if (elem->funName) {
            APPEND_STRING_TO_STACK(elem->funName);
            APPEND_CHAR_TO_STACK('(');
            for (i = 0; i != elem->argc; i++, values++) {
                if (i > 0)
                    APPEND_CHAR_TO_STACK(',');
                str = ValueToShortSource(cx, *values);
                if (!str)
                    goto bad;
                APPEND_STRING_TO_STACK(str);
            }
            APPEND_CHAR_TO_STACK(')');
        }
        APPEND_CHAR_TO_STACK('@');
        if (elem->filename) {
            for (cp = elem->filename; *cp; cp++)
                APPEND_CHAR_TO_STACK(*cp);
        }
        APPEND_CHAR_TO_STACK(':');
        JS_snprintf(ulnbuf, sizeof ulnbuf, "%u", elem->ulineno);
        for (cp = ulnbuf; *cp; cp++)
            APPEND_CHAR_TO_STACK(*cp);
        APPEND_CHAR_TO_STACK('\n');
    }
#undef APPEND_CHAR_TO_STACK
#undef APPEND_STRING_TO_STACK
#undef STACK_LENGTH_LIMIT

  done:
    if (stacklen == 0) {
        JS_ASSERT(!stackbuf);
        return cx->runtime->emptyString;
    }
    if (stacklen < stackmax) {
        /*
         * Realloc can fail when shrinking on some FreeBSD versions, so
         * don't use JS_realloc here; simply let the oversized allocation
         * be owned by the string in that rare case.
         */
        void *shrunk = JS_realloc(cx, stackbuf, (stacklen+1) * sizeof(jschar));
        if (shrunk)
            stackbuf = shrunk;
    }

    stackbuf[stacklen] = 0;
    str = js_NewString(cx, stackbuf, stacklen, 0);
    if (str)
        return str;

  bad:
    if (stackbuf)
        JS_free(cx, stackbuf);
    return NULL;
}

/* XXXbe Consolidate the ugly truth that we don't treat filename as UTF-8
         with these two functions. */
static JSString *
FilenameToString(JSContext *cx, const char *filename)
{
    return JS_NewStringCopyZ(cx, filename);
}

static const char *
StringToFilename(JSContext *cx, JSString *str)
{
    return JS_GetStringBytes(str);
}

static JSBool
Exception(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    JSBool ok;
    uint32 lineno;
    JSString *message, *filename;
    JSStackFrame *fp;

    if (cx->creatingException)
        return JS_FALSE;
    cx->creatingException = JS_TRUE;

    if (!(cx->fp->flags & JSFRAME_CONSTRUCTING)) {
        /*
         * ECMA ed. 3, 15.11.1 requires Error, etc., to construct even when
         * called as functions, without operator new.  But as we do not give
         * each constructor a distinct JSClass, whose .name member is used by
         * js_NewObject to find the class prototype, we must get the class
         * prototype ourselves.
         */
        ok = OBJ_GET_PROPERTY(cx, JSVAL_TO_OBJECT(argv[-2]),
                              ATOM_TO_JSID(cx->runtime->atomState
                                           .classPrototypeAtom),
                              rval);
        if (!ok)
            goto out;
        obj = js_NewObject(cx, &js_ErrorClass, JSVAL_TO_OBJECT(*rval), NULL);
        if (!obj) {
            ok = JS_FALSE;
            goto out;
        }
        *rval = OBJECT_TO_JSVAL(obj);
    }

    /*
     * If it's a new object of class Exception, then null out the private
     * data so that the finalizer doesn't attempt to free it.
     */
    if (OBJ_GET_CLASS(cx, obj) == &js_ErrorClass)
        OBJ_SET_SLOT(cx, obj, JSSLOT_PRIVATE, JSVAL_VOID);

    /* Set the 'message' property. */
    if (argc != 0) {
        message = js_ValueToString(cx, argv[0]);
        if (!message) {
            ok = JS_FALSE;
            goto out;
        }
        argv[0] = STRING_TO_JSVAL(message);
    } else {
        message = cx->runtime->emptyString;
    }

    /* Set the 'fileName' property. */
    if (argc > 1) {
        filename = js_ValueToString(cx, argv[1]);
        if (!filename) {
            ok = JS_FALSE;
            goto out;
        }
        argv[1] = STRING_TO_JSVAL(filename);
        fp = NULL;
    } else {
        fp = JS_GetScriptedCaller(cx, NULL);
        if (fp) {
            filename = FilenameToString(cx, fp->script->filename);
            if (!filename) {
                ok = JS_FALSE;
                goto out;
            }
        } else {
            filename = cx->runtime->emptyString;
        }
    }

    /* Set the 'lineNumber' property. */
    if (argc > 2) {
        ok = js_ValueToECMAUint32(cx, argv[2], &lineno);
        if (!ok)
            goto out;
    } else {
        if (!fp)
            fp = JS_GetScriptedCaller(cx, NULL);
        lineno = (fp && fp->pc) ? js_PCToLineNumber(cx, fp->script, fp->pc) : 0;
    }

    ok = (OBJ_GET_CLASS(cx, obj) != &js_ErrorClass) ||
         InitExnPrivate(cx, obj, message, filename, lineno, NULL);

  out:
    cx->creatingException = JS_FALSE;
    return ok;
}

/*
 * Convert to string.
 *
 * This method only uses JavaScript-modifiable properties name, message.  It
 * is left to the host to check for private data and report filename and line
 * number information along with this message.
 */
static JSBool
exn_toString(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    jsval v;
    JSString *name, *message, *result;
    jschar *chars, *cp;
    size_t name_length, message_length, length;

    if (!OBJ_GET_PROPERTY(cx, obj,
                          ATOM_TO_JSID(cx->runtime->atomState.nameAtom),
                          &v)) {
        return JS_FALSE;
    }
    name = JSVAL_IS_STRING(v) ? JSVAL_TO_STRING(v) : cx->runtime->emptyString;
    *rval = STRING_TO_JSVAL(name);

    if (!JS_GetProperty(cx, obj, js_message_str, &v))
        return JS_FALSE;
    message = JSVAL_IS_STRING(v) ? JSVAL_TO_STRING(v)
                                 : cx->runtime->emptyString;

    if (JSSTRING_LENGTH(message) != 0) {
        name_length = JSSTRING_LENGTH(name);
        message_length = JSSTRING_LENGTH(message);
        length = (name_length ? name_length + 2 : 0) + message_length;
        cp = chars = (jschar*) JS_malloc(cx, (length + 1) * sizeof(jschar));
        if (!chars)
            return JS_FALSE;

        if (name_length) {
            js_strncpy(cp, JSSTRING_CHARS(name), name_length);
            cp += name_length;
            *cp++ = ':'; *cp++ = ' ';
        }
        js_strncpy(cp, JSSTRING_CHARS(message), message_length);
        cp += message_length;
        *cp = 0;

        result = js_NewString(cx, chars, length, 0);
        if (!result) {
            JS_free(cx, chars);
            return JS_FALSE;
        }
    } else {
        result = name;
    }

    *rval = STRING_TO_JSVAL(result);
    return JS_TRUE;
}

#if JS_HAS_TOSOURCE
/*
 * Return a string that may eval to something similar to the original object.
 */
static JSBool
exn_toSource(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    jsval *vp;
    JSString *name, *message, *filename, *lineno_as_str, *result;
    uint32 lineno;
    size_t lineno_length, name_length, message_length, filename_length, length;
    jschar *chars, *cp;

    vp = argv + argc;   /* beginning of explicit local roots */

    if (!OBJ_GET_PROPERTY(cx, obj,
                          ATOM_TO_JSID(cx->runtime->atomState.nameAtom),
                          rval)) {
        return JS_FALSE;
    }
    name = js_ValueToString(cx, *rval);