JSBool
js_ErrorToException(JSContext *cx, const char *message, JSErrorReport *reportp)
{
JSErrNum errorNumber;
JSExnType exn;
JSBool ok;
JSObject *errProto, *errObject;
JSString *messageStr, *filenameStr;
uintN lineno;
JSExnPrivate *privateData;
const JSErrorFormatString *errorString;
/*
* Tell our caller to report immediately if cx has no active frames, or if
* this report is just a warning.
*/
JS_ASSERT(reportp);
if (!cx->fp || JSREPORT_IS_WARNING(reportp->flags))
return JS_FALSE;
/* Find the exception index associated with this error. */
errorNumber = (JSErrNum) reportp->errorNumber;
errorString = js_GetLocalizedErrorMessage(cx, NULL, NULL, errorNumber);
exn = errorString ? errorString->exnType : JSEXN_NONE;
JS_ASSERT(exn < JSEXN_LIMIT);
#if defined( DEBUG_mccabe ) && defined ( PRINTNAMES )
/* Print the error name and the associated exception name to stderr */
fprintf(stderr, "%s\t%s\n",
errortoexnname[errorNumber].name,
errortoexnname[errorNumber].exception);
#endif
/*
* Return false (no exception raised) if no exception is associated
* with the given error number.
*/
if (exn == JSEXN_NONE)
return JS_FALSE;
/*
* Prevent runaway recursion, just as the Exception native constructor
* must do, via cx->creatingException. If an out-of-memory error occurs,
* no exception object will be created, but we don't assume that OOM is
* the only kind of error that subroutines of this function called below
* might raise.
*/
if (cx->creatingException)
return JS_FALSE;
cx->creatingException = JS_TRUE;
/* Protect the newly-created strings below from nesting GCs. */
ok = js_EnterLocalRootScope(cx);
if (!ok)
goto out;
/*
* Try to get an appropriate prototype by looking up the corresponding
* exception constructor name in the scope chain of the current context's
* top stack frame, or in the global object if no frame is active.
*/
ok = js_GetClassPrototype(cx, exceptions[exn].name, &errProto);
if (!ok)
goto out;
errObject = js_NewObject(cx, &ExceptionClass, errProto, NULL);
if (!errObject) {
ok = JS_FALSE;
goto out;
}
/*
* Set the generated Exception object early, so it won't be GC'd by a last
* ditch attempt to collect garbage, or a GC that otherwise nests or races
* under any of the following calls. If one of the following calls fails,
* it will overwrite this exception object with one of its own (except in
* case of OOM errors, of course).
*/
JS_SetPendingException(cx, OBJECT_TO_JSVAL(errObject));
messageStr = JS_NewStringCopyZ(cx, message);
if (!messageStr) {
ok = JS_FALSE;
goto out;
}
if (reportp) {
filenameStr = JS_NewStringCopyZ(cx, reportp->filename);
if (!filenameStr) {
ok = JS_FALSE;
goto out;
}
lineno = reportp->lineno;
} else {
filenameStr = cx->runtime->emptyString;
lineno = 0;
}
ok = InitExceptionObject(cx, errObject, messageStr, filenameStr, lineno);
if (!ok)
goto out;
/*
* Construct a new copy of the error report struct, and store it in the
* exception object's private data. We can't use the error report struct
* that was passed in, because it's stack-allocated, and also because it
* may point to transient data in the JSTokenStream.
*/
privateData = exn_newPrivate(cx, reportp);
if (!privateData) {
ok = JS_FALSE;
goto out;
}
OBJ_SET_SLOT(cx, errObject, JSSLOT_PRIVATE, PRIVATE_TO_JSVAL(privateData));
/* Flag the error report passed in to indicate an exception was raised. */
reportp->flags |= JSREPORT_EXCEPTION;
out:
js_LeaveLocalRootScope(cx);
cx->creatingException = JS_FALSE;
return ok;
}
JSObject *
js_InitExceptionClasses(JSContext *cx, JSObject *obj)
{
JSObject *obj_proto, *protos[JSEXN_LIMIT];
int i;
/*
* If lazy class initialization occurs for any Error subclass, then all
* classes are initialized, starting with Error. To avoid reentry and
* redundant initialization, we must not pass a null proto parameter to
* js_NewObject below, when called for the Error superclass. We need to
* ensure that Object.prototype is the proto of Error.prototype.
*
* See the equivalent code to ensure that parent_proto is non-null when
* JS_InitClass calls js_NewObject, in jsapi.c.
*/
if (!js_GetClassPrototype(cx, obj, INT_TO_JSID(JSProto_Object),
&obj_proto)) {
return NULL;
}
if (!js_EnterLocalRootScope(cx))
return NULL;
/* Initialize the prototypes first. */
for (i = 0; exceptions[i].name != 0; i++) {
JSAtom *atom;
JSFunction *fun;
JSString *nameString;
int protoIndex = exceptions[i].protoIndex;
/* Make the prototype for the current constructor name. */
protos[i] = js_NewObject(cx, &js_ErrorClass,
(protoIndex != JSEXN_NONE)
? protos[protoIndex]
: obj_proto,
obj, 0);
if (!protos[i])
break;
/* So exn_finalize knows whether to destroy private data. */
STOBJ_SET_SLOT(protos[i], JSSLOT_PRIVATE, JSVAL_VOID);
/* Make a constructor function for the current name. */
atom = cx->runtime->atomState.classAtoms[exceptions[i].key];
fun = js_DefineFunction(cx, obj, atom, exceptions[i].native, 3, 0);
if (!fun)
break;
/* Make this constructor make objects of class Exception. */
fun->u.n.clasp = &js_ErrorClass;
/* Make the prototype and constructor links. */
if (!js_SetClassPrototype(cx, FUN_OBJECT(fun), protos[i],
JSPROP_READONLY | JSPROP_PERMANENT)) {
break;
}
/* proto bootstrap bit from JS_InitClass omitted. */
nameString = JS_NewStringCopyZ(cx, exceptions[i].name);
if (!nameString)
break;
/* Add the name property to the prototype. */
if (!JS_DefineProperty(cx, protos[i], js_name_str,
STRING_TO_JSVAL(nameString),
NULL, NULL,
JSPROP_ENUMERATE)) {
break;
}
/* Finally, stash the constructor for later uses. */
if (!js_SetClassObject(cx, obj, exceptions[i].key, FUN_OBJECT(fun)))
break;
}
js_LeaveLocalRootScope(cx);
if (exceptions[i].name)
return NULL;
/*
* Add an empty message property. (To Exception.prototype only,
* because this property will be the same for all the exception
* protos.)
*/
if (!JS_DefineProperty(cx, protos[0], js_message_str,
STRING_TO_JSVAL(cx->runtime->emptyString),
NULL, NULL, JSPROP_ENUMERATE)) {
return NULL;
}
if (!JS_DefineProperty(cx, protos[0], js_fileName_str,
STRING_TO_JSVAL(cx->runtime->emptyString),
NULL, NULL, JSPROP_ENUMERATE)) {
return NULL;
}
if (!JS_DefineProperty(cx, protos[0], js_lineNumber_str,
INT_TO_JSVAL(0),
NULL, NULL, JSPROP_ENUMERATE)) {
return NULL;
}
/*
* Add methods only to Exception.prototype, because ostensibly all
* exception types delegate to that.
*/
if (!JS_DefineFunctions(cx, protos[0], exception_methods))
return NULL;
return protos[0];
}
JSObject *
js_InitExceptionClasses(JSContext *cx, JSObject *obj)
{
int i;
JSObject *protos[JSEXN_LIMIT];
if (!js_EnterLocalRootScope(cx))
return NULL;
/* Initialize the prototypes first. */
for (i = 0; exceptions[i].name != 0; i++) {
JSAtom *atom;
JSFunction *fun;
JSString *nameString;
int protoIndex = exceptions[i].protoIndex;
/* Make the prototype for the current constructor name. */
protos[i] = js_NewObject(cx, &ExceptionClass,
(protoIndex != JSEXN_NONE)
? protos[protoIndex]
: NULL,
obj);
if (!protos[i])
break;
/* So exn_finalize knows whether to destroy private data. */
OBJ_SET_SLOT(cx, protos[i], JSSLOT_PRIVATE, JSVAL_VOID);
atom = js_Atomize(cx, exceptions[i].name, strlen(exceptions[i].name), 0);
if (!atom)
break;
/* Make a constructor function for the current name. */
fun = js_DefineFunction(cx, obj, atom, exceptions[i].native, 3, 0);
if (!fun)
break;
/* Make this constructor make objects of class Exception. */
fun->clasp = &ExceptionClass;
/* Make the prototype and constructor links. */
if (!js_SetClassPrototype(cx, fun->object, protos[i],
JSPROP_READONLY | JSPROP_PERMANENT)) {
break;
}
/* proto bootstrap bit from JS_InitClass omitted. */
nameString = JS_NewStringCopyZ(cx, exceptions[i].name);
if (!nameString)
break;
/* Add the name property to the prototype. */
if (!JS_DefineProperty(cx, protos[i], js_name_str,
STRING_TO_JSVAL(nameString),
NULL, NULL,
JSPROP_ENUMERATE)) {
break;
}
}
js_LeaveLocalRootScope(cx);
if (exceptions[i].name)
return NULL;
/*
* Add an empty message property. (To Exception.prototype only,
* because this property will be the same for all the exception
* protos.)
*/
if (!JS_DefineProperty(cx, protos[0], js_message_str,
STRING_TO_JSVAL(cx->runtime->emptyString),
NULL, NULL, JSPROP_ENUMERATE)) {
return NULL;
}
if (!JS_DefineProperty(cx, protos[0], js_filename_str,
STRING_TO_JSVAL(cx->runtime->emptyString),
NULL, NULL, JSPROP_ENUMERATE)) {
return NULL;
}
if (!JS_DefineProperty(cx, protos[0], js_lineno_str,
INT_TO_JSVAL(0),
NULL, NULL, JSPROP_ENUMERATE)) {
return NULL;
}
/*
* Add methods only to Exception.prototype, because ostensibly all
* exception types delegate to that.
*/
if (!JS_DefineFunctions(cx, protos[0], exception_methods))
return NULL;
return protos[0];
}
