jsscript.c

java script test programing source code

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sw=4 et tw=78:
 *
 * ***** 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 script operations.
 */
#include "jsstddef.h"
#include <string.h>
#include "jstypes.h"
#include "jsutil.h" /* Added by JSIFY */
#include "jsprf.h"
#include "jsapi.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsconfig.h"
#include "jsdbgapi.h"
#include "jsemit.h"
#include "jsfun.h"
#include "jsinterp.h"
#include "jslock.h"
#include "jsnum.h"
#include "jsopcode.h"
#include "jsscript.h"
#if JS_HAS_XDR
#include "jsxdrapi.h"
#endif

#if JS_HAS_SCRIPT_OBJECT

static const char js_script_exec[] = "Script.prototype.exec";
static const char js_script_compile[] = "Script.prototype.compile";

/*
 * This routine requires that obj has been locked previously.
 */
static jsint
GetScriptExecDepth(JSContext *cx, JSObject *obj)
{
    jsval v;

    JS_ASSERT(JS_IS_OBJ_LOCKED(cx, obj));
    v = LOCKED_OBJ_GET_SLOT(obj, JSSLOT_START(&js_ScriptClass));
    return JSVAL_TO_INT(v);
}

static void
AdjustScriptExecDepth(JSContext *cx, JSObject *obj, jsint delta)
{
    jsint execDepth;

    JS_LOCK_OBJ(cx, obj);
    execDepth = GetScriptExecDepth(cx, obj);
    LOCKED_OBJ_SET_SLOT(obj, JSSLOT_START(&js_ScriptClass),
                        INT_TO_JSVAL(execDepth + delta));
    JS_UNLOCK_OBJ(cx, obj);
}

#if JS_HAS_TOSOURCE
static JSBool
script_toSource(JSContext *cx, JSObject *obj, uintN argc, jsval *argv,
                jsval *rval)
{
    uint32 indent;
    JSScript *script;
    size_t i, j, k, n;
    char buf[16];
    jschar *s, *t;
    JSString *str;

    if (!JS_InstanceOf(cx, obj, &js_ScriptClass, argv))
        return JS_FALSE;

    indent = 0;
    if (argc && !js_ValueToECMAUint32(cx, argv[0], &indent))
        return JS_FALSE;

    script = (JSScript *) JS_GetPrivate(cx, obj);

    /* Let n count the source string length, j the "front porch" length. */
    j = JS_snprintf(buf, sizeof buf, "(new %s(", js_ScriptClass.name);
    n = j + 2;
    if (!script) {
        /* Let k count the constructor argument string length. */
        k = 0;
        s = NULL;               /* quell GCC overwarning */
    } else {
        str = JS_DecompileScript(cx, script, "Script.prototype.toSource",
                                 (uintN)indent);
        if (!str)
            return JS_FALSE;
        str = js_QuoteString(cx, str, '\'');
        if (!str)
            return JS_FALSE;
        s = JSSTRING_CHARS(str);
        k = JSSTRING_LENGTH(str);
        n += k;
    }

    /* Allocate the source string and copy into it. */
    t = (jschar *) JS_malloc(cx, (n + 1) * sizeof(jschar));
    if (!t)
        return JS_FALSE;
    for (i = 0; i < j; i++)
        t[i] = buf[i];
    for (j = 0; j < k; i++, j++)
        t[i] = s[j];
    t[i++] = ')';
    t[i++] = ')';
    t[i] = 0;

    /* Create and return a JS string for t. */
    str = JS_NewUCString(cx, t, n);
    if (!str) {
        JS_free(cx, t);
        return JS_FALSE;
    }
    *rval = STRING_TO_JSVAL(str);
    return JS_TRUE;
}
#endif /* JS_HAS_TOSOURCE */

static JSBool
script_toString(JSContext *cx, JSObject *obj, uintN argc, jsval *argv,
                jsval *rval)
{
    uint32 indent;
    JSScript *script;
    JSString *str;

    indent = 0;
    if (argc && !js_ValueToECMAUint32(cx, argv[0], &indent))
        return JS_FALSE;

    if (!JS_InstanceOf(cx, obj, &js_ScriptClass, argv))
        return JS_FALSE;
    script = (JSScript *) JS_GetPrivate(cx, obj);
    if (!script) {
        *rval = STRING_TO_JSVAL(cx->runtime->emptyString);
        return JS_TRUE;
    }

    str = JS_DecompileScript(cx, script, "Script.prototype.toString",
                             (uintN)indent);
    if (!str)
        return JS_FALSE;
    *rval = STRING_TO_JSVAL(str);
    return JS_TRUE;
}

static JSBool
script_compile(JSContext *cx, JSObject *obj, uintN argc, jsval *argv,
               jsval *rval)
{
    JSString *str;
    JSObject *scopeobj;
    jsval v;
    JSScript *script, *oldscript;
    JSStackFrame *fp, *caller;
    const char *file;
    uintN line;
    JSPrincipals *principals;
    jsint execDepth;

    /* Make sure obj is a Script object. */
    if (!JS_InstanceOf(cx, obj, &js_ScriptClass, argv))
        return JS_FALSE;

    /* If no args, leave private undefined and return early. */
    if (argc == 0)
        goto out;

    /* Otherwise, the first arg is the script source to compile. */
    str = js_ValueToString(cx, argv[0]);
    if (!str)
        return JS_FALSE;
    argv[0] = STRING_TO_JSVAL(str);

    scopeobj = NULL;
    if (argc >= 2) {
        if (!js_ValueToObject(cx, argv[1], &scopeobj))
            return JS_FALSE;
        argv[1] = OBJECT_TO_JSVAL(scopeobj);
    }

    /* Compile using the caller's scope chain, which js_Invoke passes to fp. */
    fp = cx->fp;
    caller = JS_GetScriptedCaller(cx, fp);
    JS_ASSERT(!caller || fp->scopeChain == caller->scopeChain);

    if (caller) {
        if (!scopeobj) {
            scopeobj = js_GetScopeChain(cx, caller);
            if (!scopeobj)
                return JS_FALSE;
            fp->scopeChain = scopeobj;  /* for the compiler's benefit */
        }

        principals = JS_EvalFramePrincipals(cx, fp, caller);
        if (principals == caller->script->principals) {
            file = caller->script->filename;
            line = js_PCToLineNumber(cx, caller->script, caller->pc);
        } else {
            file = principals->codebase;
            line = 0;
        }
    } else {
        file = NULL;
        line = 0;
        principals = NULL;
    }

    /* Ensure we compile this script with the right (inner) principals. */
    scopeobj = js_CheckScopeChainValidity(cx, scopeobj, js_script_compile);
    if (!scopeobj)
        return JS_FALSE;

    /*
     * Compile the new script using the caller's scope chain, a la eval().
     * Unlike jsobj.c:obj_eval, however, we do not set JSFRAME_EVAL in fp's
     * flags, because compilation is here separated from execution, and the
     * run-time scope chain may not match the compile-time.  JSFRAME_EVAL is
     * tested in jsemit.c and jsscan.c to optimize based on identity of run-
     * and compile-time scope.
     */
    fp->flags |= JSFRAME_SCRIPT_OBJECT;
    script = JS_CompileUCScriptForPrincipals(cx, scopeobj, principals,
                                             JSSTRING_CHARS(str),
                                             JSSTRING_LENGTH(str),
                                             file, line);
    if (!script)
        return JS_FALSE;

    JS_LOCK_OBJ(cx, obj);
    execDepth = GetScriptExecDepth(cx, obj);

    /*
     * execDepth must be 0 to allow compilation here, otherwise the JSScript
     * struct can be released while running.
     */
    if (execDepth > 0) {
        JS_UNLOCK_OBJ(cx, obj);
        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
                             JSMSG_COMPILE_EXECED_SCRIPT);
        return JS_FALSE;
    }

    /* Swap script for obj's old script, if any. */
    v = LOCKED_OBJ_GET_SLOT(obj, JSSLOT_PRIVATE);
    oldscript = !JSVAL_IS_VOID(v) ? (JSScript *) JSVAL_TO_PRIVATE(v) : NULL;
    LOCKED_OBJ_SET_SLOT(obj, JSSLOT_PRIVATE, PRIVATE_TO_JSVAL(script));
    JS_UNLOCK_OBJ(cx, obj);

    if (oldscript)
        js_DestroyScript(cx, oldscript);

    script->object = obj;
    js_CallNewScriptHook(cx, script, NULL);

out:
    /* Return the object. */
    *rval = OBJECT_TO_JSVAL(obj);
    return JS_TRUE;
}

static JSBool
script_exec(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
    JSObject *scopeobj, *parent;
    JSStackFrame *fp, *caller;
    JSScript *script;
    JSBool ok;

    if (!JS_InstanceOf(cx, obj, &js_ScriptClass, argv))
        return JS_FALSE;

    scopeobj = NULL;
    if (argc) {
        if (!js_ValueToObject(cx, argv[0], &scopeobj))
            return JS_FALSE;
        argv[0] = OBJECT_TO_JSVAL(scopeobj);
    }

    /*
     * Emulate eval() by using caller's this, var object, sharp array, etc.,
     * all propagated by js_Execute via a non-null fourth (down) argument to
     * js_Execute.  If there is no scripted caller, js_Execute uses its second
     * (chain) argument to set the exec frame's varobj, thisp, and scopeChain.
     *
     * Unlike eval, which the compiler detects, Script.prototype.exec may be
     * called from a lightweight function, or even from native code (in which
     * case fp->varobj and fp->scopeChain are null).  If exec is called from
     * a lightweight function, we will need to get a Call object representing
     * its frame, to act as the var object and scope chain head.
     */
    fp = cx->fp;
    caller = JS_GetScriptedCaller(cx, fp);
    if (caller && !caller->varobj) {
        /* Called from a lightweight function. */
        JS_ASSERT(caller->fun && !JSFUN_HEAVYWEIGHT_TEST(caller->fun->flags));

        /* Scope chain links from Call object to callee's parent. */
        parent = OBJ_GET_PARENT(cx, JSVAL_TO_OBJECT(caller->argv[-2]));
        if (!js_GetCallObject(cx, caller, parent))
            return JS_FALSE;
    }

    if (!scopeobj) {
        /* No scope object passed in: try to use the caller's scope chain. */
        if (caller) {
            /*
             * Load caller->scopeChain after the conditional js_GetCallObject
             * call above, which resets scopeChain as well as varobj.
             */
            scopeobj = js_GetScopeChain(cx, caller);
            if (!scopeobj)
                return JS_FALSE;
        } else {
            /*
             * Called from native code, so we don't know what scope object to
             * use.  We could use parent (see above), but Script.prototype.exec
             * might be a shared/sealed "superglobal" method.  A more general
             * approach would use cx->globalObject, which will be the same as
             * exec.__parent__ in the non-superglobal case.  In the superglobal
             * case it's the right object: the global, not the superglobal.
             */
            scopeobj = cx->globalObject;
        }
    }

    scopeobj = js_CheckScopeChainValidity(cx, scopeobj, js_script_exec);
    if (!scopeobj)
        return JS_FALSE;

    /* Keep track of nesting depth for the script. */
    AdjustScriptExecDepth(cx, obj, 1);

    /* Must get to out label after this */
    script = (JSScript *) JS_GetPrivate(cx, obj);
    if (!script) {
        ok = JS_FALSE;
        goto out;
    }

    /* Belt-and-braces: check that this script object has access to scopeobj. */
    ok = js_CheckPrincipalsAccess(cx, scopeobj, script->principals,
                                  CLASS_ATOM(cx, Script));
    if (!ok)
        goto out;

    ok = js_Execute(cx, scopeobj, script, caller, JSFRAME_EVAL, rval);
   
out:
    AdjustScriptExecDepth(cx, obj, -1); 
    return ok;
}

#if JS_HAS_XDR

static JSBool
XDRAtomMap(JSXDRState *xdr, JSAtomMap *map)
{
    JSContext *cx;
    uint32 natoms, i, index;
    JSAtom **atoms;

    cx = xdr->cx;

    if (xdr->mode == JSXDR_ENCODE)
        natoms = (uint32)map->length;

    if (!JS_XDRUint32(xdr, &natoms))
        return JS_FALSE;

    if (xdr->mode == JSXDR_ENCODE) {
        atoms = map->vector;
    } else {
        if (natoms == 0) {
            atoms = NULL;
        } else {
            atoms = (JSAtom **) JS_malloc(cx, (size_t)natoms * sizeof *atoms);
            if (!atoms)
                return JS_FALSE;
#ifdef DEBUG
            memset(atoms, 0, (size_t)natoms * sizeof *atoms);
#endif
        }

        map->vector = atoms;
        map->length = natoms;
    }

    for (i = 0; i != natoms; ++i) {
        if (xdr->mode == JSXDR_ENCODE)