gecko-dev/js/src/jsexn.h

120 lines
4.5 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* JS runtime exception classes.
*/
#ifndef jsexn_h
#define jsexn_h
#include "jsapi.h"
#include "NamespaceImports.h"
namespace js {
class ErrorObject;
JSErrorReport *
CopyErrorReport(JSContext *cx, JSErrorReport *report);
JSString *
ComputeStackString(JSContext *cx);
}
/*
* Given a JSErrorReport, check to see if there is an exception associated with
* the error number. If there is, then create an appropriate exception object,
* set it as the pending exception, and set the JSREPORT_EXCEPTION flag on the
* error report. Exception-aware host error reporters should probably ignore
* error reports so flagged.
*
* Return true if cx->throwing and cx->exception were set.
*
* This means that:
*
* - If the error is successfully converted to an exception and stored in
* cx->exception, the return value is true. This is the "normal", happiest
* case for the caller.
*
* - If we try to convert, but fail with OOM or some other error that ends up
* setting cx->throwing to true and setting cx->exception, then we also
* return true (because callers want to treat that case the same way).
* The original error described by *reportp typically won't be reported
* anywhere; instead OOM is reported.
*
* - If *reportp is just a warning, or the error code is unrecognized, or if
* we decided to do nothing in order to avoid recursion, then return
* false. In those cases, this error is just being swept under the rug
* unless the caller decides to call CallErrorReporter explicitly.
*/
extern bool
js_ErrorToException(JSContext *cx, const char *message, JSErrorReport *reportp,
JSErrorCallback callback, void *userRef);
/*
* Called if a JS API call to js_Execute or js_InternalCall fails; calls the
* error reporter with the error report associated with any uncaught exception
* that has been raised. Returns true if there was an exception pending, and
* the error reporter was actually called.
*
* The JSErrorReport * that the error reporter is called with is currently
* associated with a JavaScript object, and is not guaranteed to persist after
* the object is collected. Any persistent uses of the JSErrorReport contents
* should make their own copy.
*
* The flags field of the JSErrorReport will have the JSREPORT_EXCEPTION flag
* set; embeddings that want to silently propagate JavaScript exceptions to
* other contexts may want to use an error reporter that ignores errors with
* this flag.
*/
extern bool
js_ReportUncaughtException(JSContext *cx);
extern JSErrorReport *
js_ErrorFromException(JSContext *cx, js::HandleObject obj);
/*
* Make a copy of errobj parented to cx's compartment's global.
*
* errobj may be in a different compartment than cx, but it must be an Error
* object (not a wrapper of one) and it must not be one of the standard error
* prototype objects (errobj->getPrivate() must not be nullptr).
*/
extern JSObject *
js_CopyErrorObject(JSContext *cx, JS::Handle<js::ErrorObject*> errobj);
static_assert(JSEXN_ERR == 0 &&
JSProto_Error + JSEXN_INTERNALERR == JSProto_InternalError &&
JSProto_Error + JSEXN_EVALERR == JSProto_EvalError &&
JSProto_Error + JSEXN_RANGEERR == JSProto_RangeError &&
JSProto_Error + JSEXN_REFERENCEERR == JSProto_ReferenceError &&
JSProto_Error + JSEXN_SYNTAXERR == JSProto_SyntaxError &&
JSProto_Error + JSEXN_TYPEERR == JSProto_TypeError &&
JSProto_Error + JSEXN_URIERR == JSProto_URIError &&
JSEXN_URIERR + 1 == JSEXN_LIMIT,
"GetExceptionProtoKey and ExnTypeFromProtoKey require that "
"each corresponding JSExnType and JSProtoKey value be separated "
"by the same constant value");
static inline JSProtoKey
GetExceptionProtoKey(JSExnType exn)
{
MOZ_ASSERT(JSEXN_ERR <= exn);
MOZ_ASSERT(exn < JSEXN_LIMIT);
return JSProtoKey(JSProto_Error + int(exn));
}
static inline JSExnType
ExnTypeFromProtoKey(JSProtoKey key)
{
JSExnType type = static_cast<JSExnType>(key - JSProto_Error);
MOZ_ASSERT(type >= JSEXN_ERR);
MOZ_ASSERT(type < JSEXN_LIMIT);
return type;
}
#endif /* jsexn_h */