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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
/* Code for throwing errors into JavaScript. */
#include "xpcprivate.h"
#include "XPCWrapper.h"
#include "js/CharacterEncoding.h"
#include "js/Printf.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/Exceptions.h"
#include "nsString.h"
using namespace mozilla;
using namespace mozilla::dom;
bool XPCThrower::sVerbose = true;
// static
void XPCThrower::Throw(nsresult rv, JSContext* cx) {
const char* format;
if (JS_IsExceptionPending(cx)) {
return;
}
if (!nsXPCException::NameAndFormatForNSResult(rv, nullptr, &format)) {
format = "";
}
dom::Throw(cx, rv, nsDependentCString(format));
}
namespace xpc {
bool Throw(JSContext* cx, nsresult rv) {
XPCThrower::Throw(rv, cx);
return false;
}
} // namespace xpc
/*
* If there has already been an exception thrown, see if we're throwing the
* same sort of exception, and if we are, don't clobber the old one. ccx
* should be the current call context.
*/
// static
bool XPCThrower::CheckForPendingException(nsresult result, JSContext* cx) {
RefPtr<Exception> e = XPCJSContext::Get()->GetPendingException();
if (!e) {
return false;
}
XPCJSContext::Get()->SetPendingException(nullptr);
if (e->GetResult() != result) {
return false;
}
ThrowExceptionObject(cx, e);
return true;
}
// static
void XPCThrower::Throw(nsresult rv, XPCCallContext& ccx) {
char* sz;
const char* format;
if (CheckForPendingException(rv, ccx)) {
return;
}
if (!nsXPCException::NameAndFormatForNSResult(rv, nullptr, &format)) {
format = "";
}
sz = (char*)format;
NS_ENSURE_TRUE_VOID(sz);
if (sz && sVerbose) {
Verbosify(ccx, &sz, false);
}
dom::Throw(ccx, rv, nsDependentCString(sz));
if (sz && sz != format) {
js_free(sz);
}
}
// static
void XPCThrower::ThrowBadResult(nsresult rv, nsresult result,
XPCCallContext& ccx) {
char* sz;
const char* format;
const char* name;
/*
* If there is a pending exception when the native call returns and
* it has the same error result as returned by the native call, then
* the native call may be passing through an error from a previous JS
* call. So we'll just throw that exception into our JS. Note that
* we don't need to worry about NS_ERROR_UNCATCHABLE_EXCEPTION,
* because presumably there would be no pending exception for that
* nsresult!
*/
if (CheckForPendingException(result, ccx)) {
return;
}
// else...
if (!nsXPCException::NameAndFormatForNSResult(rv, nullptr, &format) ||
!format) {
format = "";
}
if (nsXPCException::NameAndFormatForNSResult(result, &name, nullptr) &&
name) {
sz = JS_smprintf("%s 0x%x (%s)", format, (unsigned)result, name).release();
} else {
sz = JS_smprintf("%s 0x%x", format, (unsigned)result).release();
}
NS_ENSURE_TRUE_VOID(sz);
if (sz && sVerbose) {
Verbosify(ccx, &sz, true);
}
dom::Throw(ccx, result, nsDependentCString(sz));
if (sz) {
js_free(sz);
}
}
// static
void XPCThrower::ThrowBadParam(nsresult rv, unsigned paramNum,
XPCCallContext& ccx) {
char* sz;
const char* format;
if (!nsXPCException::NameAndFormatForNSResult(rv, nullptr, &format)) {
format = "";
}
sz = JS_smprintf("%s arg %d", format, paramNum).release();
NS_ENSURE_TRUE_VOID(sz);
if (sz && sVerbose) {
Verbosify(ccx, &sz, true);
}
dom::Throw(ccx, rv, nsDependentCString(sz));
if (sz) {
js_free(sz);
}
}
// static
void XPCThrower::Verbosify(XPCCallContext& ccx, char** psz, bool own) {
char* sz = nullptr;
if (ccx.HasInterfaceAndMember()) {
XPCNativeInterface* iface = ccx.GetInterface();
jsid id = ccx.GetMember()->GetName();
const char* name;
JS::UniqueChars bytes;
if (!JSID_IS_VOID(id)) {
bytes = JS_EncodeStringToLatin1(ccx, JSID_TO_STRING(id));
name = bytes ? bytes.get() : "";
} else {
name = "Unknown";
}
sz =
JS_smprintf("%s [%s.%s]", *psz, iface->GetNameString(), name).release();
}
if (sz) {
if (own) {
js_free(*psz);
}
*psz = sz;
}
}