jsarray.c

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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code, released
 * March 31, 1998.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * JS array class.
 */
#include "jsstddef.h"
#include <stdlib.h>
#include <string.h>
#include "jstypes.h"
#include "jsutil.h" /* Added by JSIFY */
#include "jsapi.h"
#include "jsarray.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsconfig.h"
#include "jsfun.h"
#include "jsgc.h"
#include "jsinterp.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsstr.h"

/* 2^32 - 1 as a number and a string */
#define MAXINDEX 4294967295u
#define MAXSTR   "4294967295"

/*
 * Determine if the id represents an array index.
 *
 * An id is an array index according to ECMA by (15.4):
 *
 * "Array objects give special treatment to a certain class of property names.
 * A property name P (in the form of a string value) is an array index if and
 * only if ToString(ToUint32(P)) is equal to P and ToUint32(P) is not equal
 * to 2^32-1."
 *
 * In our implementation, it would be sufficient to check for JSVAL_IS_INT(id)
 * except that by using signed 32-bit integers we miss the top half of the
 * valid range. This function checks the string representation itself; note
 * that calling a standard conversion routine might allow strings such as
 * "08" or "4.0" as array indices, which they are not.
 */
static JSBool
IdIsIndex(jsid id, jsuint *indexp)
{
    JSString *str;
    jschar *cp;

    if (JSVAL_IS_INT(id)) {
        jsint i;
        i = JSVAL_TO_INT(id);
        if (i < 0)
            return JS_FALSE;
        *indexp = (jsuint)i;
        return JS_TRUE;
    }

    /* It must be a string. */
    str = JSVAL_TO_STRING(id);
    cp = JSSTRING_CHARS(str);
    if (JS7_ISDEC(*cp) && JSSTRING_LENGTH(str) < sizeof(MAXSTR)) {
        jsuint index = JS7_UNDEC(*cp++);
        jsuint oldIndex = 0;
        jsuint c = 0;
        if (index != 0) {
            while (JS7_ISDEC(*cp)) {
                oldIndex = index;
                c = JS7_UNDEC(*cp);
                index = 10*index + c;
                cp++;
            }
        }
        /* Make sure all characters were consumed and that it couldn't
         * have overflowed.
         */
        if (*cp == 0 &&
             (oldIndex < (MAXINDEX / 10) ||
              (oldIndex == (MAXINDEX / 10) && c < (MAXINDEX % 10))))
        {
            *indexp = index;
            return JS_TRUE;
        }
    }
    return JS_FALSE;
}

static JSBool
ValueIsLength(JSContext *cx, jsval v, jsuint *lengthp)
{
    jsint i;
    jsdouble d;

    if (JSVAL_IS_INT(v)) {
        i = JSVAL_TO_INT(v);
        if (i < 0) {
            JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                                 JSMSG_BAD_ARRAY_LENGTH);
            return JS_FALSE;
        }
        *lengthp = (jsuint) i;
        return JS_TRUE;
    }
    
    if (!js_ValueToNumber(cx, v, &d)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                             JSMSG_BAD_ARRAY_LENGTH);
        return JS_FALSE;
    }
    if (!js_DoubleToECMAUint32(cx, d, (uint32 *)lengthp)) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                             JSMSG_BAD_ARRAY_LENGTH);
        return JS_FALSE;
    }
    if (JSDOUBLE_IS_NaN(d) || (uint32) d != *lengthp) {
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                             JSMSG_BAD_ARRAY_LENGTH);
        return JS_FALSE;
    }
    return JS_TRUE;
}

JSBool
js_GetLengthProperty(JSContext *cx, JSObject *obj, jsuint *lengthp)
{
    jsid id;
    jsint i;
    jsval v;

    id = (jsid) cx->runtime->atomState.lengthAtom;
    if (!OBJ_GET_PROPERTY(cx, obj, id, &v))
        return JS_FALSE;

    /* Short-circuit, because js_ValueToECMAUint32 fails when
     * called during init time.
     */
    if (JSVAL_IS_INT(v)) {
        i = JSVAL_TO_INT(v);
        /* jsuint cast does ToUint32. */
        *lengthp = (jsuint)i;
        return JS_TRUE;
    }
    return js_ValueToECMAUint32(cx, v, (uint32 *)lengthp);
}

static JSBool
IndexToValue(JSContext *cx, jsuint length, jsval *vp)
{
    if (length <= JSVAL_INT_MAX) {
        *vp = INT_TO_JSVAL(length);
        return JS_TRUE;
    }
    return js_NewDoubleValue(cx, (jsdouble)length, vp);
}

static JSBool
IndexToId(JSContext *cx, jsuint length, jsid *idp)
{
    JSString *str;
    JSAtom *atom;

    if (length <= JSVAL_INT_MAX) {
        *idp = (jsid) INT_TO_JSVAL(length);
    } else {
        str = js_NumberToString(cx, (jsdouble)length);
        if (!str)
            return JS_FALSE;
        atom = js_AtomizeString(cx, str, 0);
        if (!atom)
            return JS_FALSE;
        *idp = (jsid)atom;

    }
    return JS_TRUE;
}

JSBool
js_SetLengthProperty(JSContext *cx, JSObject *obj, jsuint length)
{
    jsval v;
    jsid id;

    if (!IndexToValue(cx, length, &v))
        return JS_FALSE;
    id = (jsid) cx->runtime->atomState.lengthAtom;
    return OBJ_SET_PROPERTY(cx, obj, id, &v);
}

JSBool
js_HasLengthProperty(JSContext *cx, JSObject *obj, jsuint *lengthp)
{
    JSErrorReporter older;
    jsid id;
    JSBool ok;
    jsval v;

    older = JS_SetErrorReporter(cx, NULL);
    id = (jsid) cx->runtime->atomState.lengthAtom;
    ok = OBJ_GET_PROPERTY(cx, obj, id, &v);
    JS_SetErrorReporter(cx, older);
    if (!ok)
        return JS_FALSE;
    return ValueIsLength(cx, v, lengthp);
}

/*
 * This get function is specific to Array.prototype.length and other array
 * instance length properties.  It calls back through the class get function
 * in case some magic happens there (see call_getProperty in jsfun.c).
 */
static JSBool
array_length_getter(JSContext *cx, JSObject *obj, jsval id, jsval *vp)
{
    return OBJ_GET_CLASS(cx, obj)->getProperty(cx, obj, id, vp);
}

static JSBool
array_length_setter(JSContext *cx, JSObject *obj, jsval id, jsval *vp)
{
    jsuint newlen, oldlen, slot;
    jsid id2;
    jsval junk;

    if (!ValueIsLength(cx, *vp, &newlen))
        return JS_FALSE;
    if (!js_GetLengthProperty(cx, obj, &oldlen))
        return JS_FALSE;
    slot = oldlen;
    while (slot > newlen) {
        --slot;
        if (!IndexToId(cx, slot, &id2))
            return JS_FALSE;
        if (!OBJ_DELETE_PROPERTY(cx, obj, id2, &junk))
            return JS_FALSE;
    }
    return IndexToValue(cx, newlen, vp);
}

static JSBool
array_addProperty(JSContext *cx, JSObject *obj, jsval id, jsval *vp)
{
    jsuint index, length;

    if (!(IdIsIndex(id, &index)))
        return JS_TRUE;
    if (!js_GetLengthProperty(cx, obj, &length))
        return JS_FALSE;
    if (index >= length) {
        length = index + 1;
        return js_SetLengthProperty(cx, obj, length);
    }
    return JS_TRUE;
}

static JSBool
array_convert(JSContext *cx, JSObject *obj, JSType type, jsval *vp)
{
    jsuint length;

    if (cx->version == JSVERSION_1_2) {
        if (!js_GetLengthProperty(cx, obj, &length))
            return JS_FALSE;
        switch (type) {
          case JSTYPE_NUMBER:
            return IndexToValue(cx, length, vp);
          case JSTYPE_BOOLEAN:
            *vp = BOOLEAN_TO_JSVAL(length > 0);
            return JS_TRUE;
          default:
            return JS_TRUE;
        }
    }
    return js_TryValueOf(cx, obj, type, vp);
}

JSClass js_ArrayClass = {
    "Array",
    0,
    array_addProperty, JS_PropertyStub,   JS_PropertyStub,   JS_PropertyStub,
    JS_EnumerateStub,  JS_ResolveStub,    array_convert,     JS_FinalizeStub,
    JSCLASS_NO_OPTIONAL_MEMBERS
};

static JSBool
array_join_sub(JSContext *cx, JSObject *obj, JSString *sep, JSBool literalize,
               jsval *rval, JSBool localeString)
{
    JSBool ok;
    jsval v;
    jsuint length, index;
    jschar *chars, *ochars;
    size_t nchars, growth, seplen, tmplen;
    const jschar *sepstr;
    JSString *str;
    JSHashEntry *he;
    JSObject *obj2;

    ok = js_GetLengthProperty(cx, obj, &length);
    if (!ok)
        return JS_FALSE;

    he = js_EnterSharpObject(cx, obj, NULL, &chars);
    if (!he)
        return JS_FALSE;
    if (literalize) {
        if (IS_SHARP(he)) {
#if JS_HAS_SHARP_VARS
            nchars = js_strlen(chars);
#else
            chars[0] = '[';
            chars[1] = ']';
            chars[2] = 0;
            nchars = 2;
#endif
            goto make_string;
        }

        /*
         * Allocate 1 + 3 + 1 for "[", the worst-case closing ", ]", and the
         * terminating 0.
         */
        growth = (1 + 3 + 1) * sizeof(jschar);
        if (!chars) {
            nchars = 0;
            chars = (jschar *) malloc(growth);
            if (!chars)
                goto done;
        } else {
            MAKE_SHARP(he);
            nchars = js_strlen(chars);
            chars = (jschar *)
                realloc((ochars = chars), nchars * sizeof(jschar) + growth);
            if (!chars) {
                free(ochars);
                goto done;
            }
        }
        chars[nchars++] = '[';
    } else {
        /*
         * Free any sharp variable definition in chars.  Normally, we would
         * MAKE_SHARP(he) so that only the first sharp variable annotation is
         * a definition, and all the rest are references, but in the current
         * case of (!literalize), we don't need chars at all.
         */
        if (chars)
            JS_free(cx, chars);
        chars = NULL;
        nchars = 0;

        /* Return the empty string on a cycle as well as on empty join. */
        if (IS_BUSY(he) || length == 0) {
            js_LeaveSharpObject(cx, NULL);
            *rval = JS_GetEmptyStringValue(cx);
            return ok;
        }

        /* Flag he as BUSY so we can distinguish a cycle from a join-point. */
        MAKE_BUSY(he);
    }
    sepstr = NULL;
    seplen = JSSTRING_LENGTH(sep);

    v = JSVAL_NULL;
    for (index = 0; index < length; index++) {
        ok = JS_GetElement(cx, obj, index, &v);
        if (!ok)
            goto done;

        if (!literalize && (JSVAL_IS_VOID(v) || JSVAL_IS_NULL(v))) {
            str = cx->runtime->emptyString;
        } else {
            if (localeString) {
                if (!js_ValueToObject(cx, v, &obj2) ||
                    !js_TryMethod(cx, obj2,
                                  cx->runtime->atomState.toLocaleStringAtom,
                                  0, NULL, &v)) {
                    str = NULL;
                } else {
                    str = js_ValueToString(cx, v);
                }
            } else {
                str = (literalize ? js_ValueToSource : js_ValueToString)(cx, v);
            }
            if (!str) {
                ok = JS_FALSE;
                goto done;
            }
        }

        /* Allocate 3 + 1 at end for ", ", closing bracket, and zero. */
        growth = (nchars + (sepstr ? seplen : 0) +
                  JSSTRING_LENGTH(str) +
                  3 + 1) * sizeof(jschar);
        if (!chars) {
            chars = (jschar *) malloc(growth);
            if (!chars)
                goto done;
        } else {
            chars = (jschar *) realloc((ochars = chars), growth);
            if (!chars) {
                free(ochars);
                goto done;
            }
        }

        if (sepstr) {
            js_strncpy(&chars[nchars], sepstr, seplen);
            nchars += seplen;
        }
        sepstr = JSSTRING_CHARS(sep);

        tmplen = JSSTRING_LENGTH(str);
        js_strncpy(&chars[nchars], JSSTRING_CHARS(str), tmplen);
        nchars += tmplen;
    }

  done:
    if (literalize) {
        if (chars) {
            if (JSVAL_IS_VOID(v)) {
                chars[nchars++] = ',';
                chars[nchars++] = ' ';
            }
            chars[nchars++] = ']';
        }
    } else {
        CLEAR_BUSY(he);
    }
    js_LeaveSharpObject(cx, NULL);
    if (!ok) {
        if (chars)
            free(chars);
        return ok;
    }

  make_string:
    if (!chars) {
        JS_ReportOutOfMemory(cx);
        return JS_FALSE;
    }