1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/bindings/Exceptions.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,548 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "mozilla/dom/Exceptions.h"
1.10 +
1.11 +#include "js/GCAPI.h"
1.12 +#include "js/OldDebugAPI.h"
1.13 +#include "jsapi.h"
1.14 +#include "jsprf.h"
1.15 +#include "mozilla/CycleCollectedJSRuntime.h"
1.16 +#include "mozilla/dom/BindingUtils.h"
1.17 +#include "mozilla/dom/DOMException.h"
1.18 +#include "nsServiceManagerUtils.h"
1.19 +#include "nsThreadUtils.h"
1.20 +#include "XPCWrapper.h"
1.21 +#include "WorkerPrivate.h"
1.22 +#include "nsContentUtils.h"
1.23 +
1.24 +namespace {
1.25 +
1.26 +// We can't use nsContentUtils::IsCallerChrome because it might not exist in
1.27 +// xpcshell.
1.28 +bool
1.29 +IsCallerChrome()
1.30 +{
1.31 + nsCOMPtr<nsIScriptSecurityManager> secMan;
1.32 + secMan = XPCWrapper::GetSecurityManager();
1.33 +
1.34 + if (!secMan) {
1.35 + return false;
1.36 + }
1.37 +
1.38 + bool isChrome;
1.39 + return NS_SUCCEEDED(secMan->SubjectPrincipalIsSystem(&isChrome)) && isChrome;
1.40 +}
1.41 +
1.42 +} // anonymous namespace
1.43 +
1.44 +namespace mozilla {
1.45 +namespace dom {
1.46 +
1.47 +bool
1.48 +ThrowExceptionObject(JSContext* aCx, nsIException* aException)
1.49 +{
1.50 + // See if we really have an Exception.
1.51 + nsCOMPtr<Exception> exception = do_QueryInterface(aException);
1.52 + if (exception) {
1.53 + return ThrowExceptionObject(aCx, exception);
1.54 + }
1.55 +
1.56 + // We only have an nsIException (probably an XPCWrappedJS). Fall back on old
1.57 + // wrapping.
1.58 + MOZ_ASSERT(NS_IsMainThread());
1.59 +
1.60 + JS::Rooted<JSObject*> glob(aCx, JS::CurrentGlobalOrNull(aCx));
1.61 + if (!glob) {
1.62 + // XXXbz Can this really be null here?
1.63 + return false;
1.64 + }
1.65 +
1.66 + JS::Rooted<JS::Value> val(aCx);
1.67 + if (!WrapObject(aCx, aException, &NS_GET_IID(nsIException), &val)) {
1.68 + return false;
1.69 + }
1.70 +
1.71 + JS_SetPendingException(aCx, val);
1.72 +
1.73 + return true;
1.74 +}
1.75 +
1.76 +bool
1.77 +ThrowExceptionObject(JSContext* aCx, Exception* aException)
1.78 +{
1.79 + JS::Rooted<JS::Value> thrown(aCx);
1.80 +
1.81 + // If we stored the original thrown JS value in the exception
1.82 + // (see XPCConvert::ConstructException) and we are in a web context
1.83 + // (i.e., not chrome), rethrow the original value. This only applies to JS
1.84 + // implemented components so we only need to check for this on the main
1.85 + // thread.
1.86 + if (NS_IsMainThread() && !IsCallerChrome() &&
1.87 + aException->StealJSVal(thrown.address())) {
1.88 + if (!JS_WrapValue(aCx, &thrown)) {
1.89 + return false;
1.90 + }
1.91 + JS_SetPendingException(aCx, thrown);
1.92 + return true;
1.93 + }
1.94 +
1.95 + JS::Rooted<JSObject*> glob(aCx, JS::CurrentGlobalOrNull(aCx));
1.96 + if (!glob) {
1.97 + // XXXbz Can this actually be null here?
1.98 + return false;
1.99 + }
1.100 +
1.101 + if (!WrapNewBindingObject(aCx, aException, &thrown)) {
1.102 + return false;
1.103 + }
1.104 +
1.105 + JS_SetPendingException(aCx, thrown);
1.106 + return true;
1.107 +}
1.108 +
1.109 +bool
1.110 +Throw(JSContext* aCx, nsresult aRv, const char* aMessage)
1.111 +{
1.112 + if (JS_IsExceptionPending(aCx)) {
1.113 + // Don't clobber the existing exception.
1.114 + return false;
1.115 + }
1.116 +
1.117 + CycleCollectedJSRuntime* runtime = CycleCollectedJSRuntime::Get();
1.118 + nsCOMPtr<nsIException> existingException = runtime->GetPendingException();
1.119 + if (existingException) {
1.120 + nsresult nr;
1.121 + if (NS_SUCCEEDED(existingException->GetResult(&nr)) &&
1.122 + aRv == nr) {
1.123 + // Reuse the existing exception.
1.124 +
1.125 + // Clear pending exception
1.126 + runtime->SetPendingException(nullptr);
1.127 +
1.128 + if (!ThrowExceptionObject(aCx, existingException)) {
1.129 + // If we weren't able to throw an exception we're
1.130 + // most likely out of memory
1.131 + JS_ReportOutOfMemory(aCx);
1.132 + }
1.133 + return false;
1.134 + }
1.135 + }
1.136 +
1.137 + nsRefPtr<Exception> finalException = CreateException(aCx, aRv, aMessage);
1.138 +
1.139 + MOZ_ASSERT(finalException);
1.140 + if (!ThrowExceptionObject(aCx, finalException)) {
1.141 + // If we weren't able to throw an exception we're
1.142 + // most likely out of memory
1.143 + JS_ReportOutOfMemory(aCx);
1.144 + }
1.145 +
1.146 + return false;
1.147 +}
1.148 +
1.149 +already_AddRefed<Exception>
1.150 +CreateException(JSContext* aCx, nsresult aRv, const char* aMessage)
1.151 +{
1.152 + // Do we use DOM exceptions for this error code?
1.153 + switch (NS_ERROR_GET_MODULE(aRv)) {
1.154 + case NS_ERROR_MODULE_DOM:
1.155 + case NS_ERROR_MODULE_SVG:
1.156 + case NS_ERROR_MODULE_DOM_XPATH:
1.157 + case NS_ERROR_MODULE_DOM_INDEXEDDB:
1.158 + case NS_ERROR_MODULE_DOM_FILEHANDLE:
1.159 + return DOMException::Create(aRv);
1.160 + default:
1.161 + break;
1.162 + }
1.163 +
1.164 + // If not, use the default.
1.165 + // aMessage can be null, so we can't use nsDependentCString on it.
1.166 + nsRefPtr<Exception> exception =
1.167 + new Exception(nsCString(aMessage), aRv,
1.168 + EmptyCString(), nullptr, nullptr);
1.169 + return exception.forget();
1.170 +}
1.171 +
1.172 +already_AddRefed<nsIStackFrame>
1.173 +GetCurrentJSStack()
1.174 +{
1.175 + // is there a current context available?
1.176 + JSContext* cx = nullptr;
1.177 +
1.178 + if (NS_IsMainThread()) {
1.179 + // Note, in xpcshell nsContentUtils is never initialized, but we still need
1.180 + // to report exceptions.
1.181 + if (nsContentUtils::XPConnect()) {
1.182 + cx = nsContentUtils::XPConnect()->GetCurrentJSContext();
1.183 + } else {
1.184 + nsCOMPtr<nsIXPConnect> xpc = do_GetService(nsIXPConnect::GetCID());
1.185 + cx = xpc->GetCurrentJSContext();
1.186 + }
1.187 + } else {
1.188 + cx = workers::GetCurrentThreadJSContext();
1.189 + }
1.190 +
1.191 + if (!cx) {
1.192 + return nullptr;
1.193 + }
1.194 +
1.195 + nsCOMPtr<nsIStackFrame> stack = exceptions::CreateStack(cx);
1.196 + if (!stack) {
1.197 + return nullptr;
1.198 + }
1.199 +
1.200 + // peel off native frames...
1.201 + uint32_t language;
1.202 + nsCOMPtr<nsIStackFrame> caller;
1.203 + while (stack &&
1.204 + NS_SUCCEEDED(stack->GetLanguage(&language)) &&
1.205 + language != nsIProgrammingLanguage::JAVASCRIPT &&
1.206 + NS_SUCCEEDED(stack->GetCaller(getter_AddRefs(caller))) &&
1.207 + caller) {
1.208 + stack = caller;
1.209 + }
1.210 + return stack.forget();
1.211 +}
1.212 +
1.213 +namespace exceptions {
1.214 +
1.215 +class StackDescriptionOwner {
1.216 +public:
1.217 + StackDescriptionOwner(JS::StackDescription* aDescription)
1.218 + : mDescription(aDescription)
1.219 + {
1.220 + mozilla::HoldJSObjects(this);
1.221 + }
1.222 +
1.223 + ~StackDescriptionOwner()
1.224 + {
1.225 + // Make sure to set mDescription to null before calling DropJSObjects, since
1.226 + // in debug builds DropJSObjects try to trace us and we don't want to trace
1.227 + // a dead StackDescription.
1.228 + if (mDescription) {
1.229 + JS::FreeStackDescription(nullptr, mDescription);
1.230 + mDescription = nullptr;
1.231 + }
1.232 + mozilla::DropJSObjects(this);
1.233 + }
1.234 +
1.235 + NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(StackDescriptionOwner)
1.236 + NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(StackDescriptionOwner)
1.237 +
1.238 + JS::FrameDescription& FrameAt(size_t aIndex)
1.239 + {
1.240 + MOZ_ASSERT(aIndex < mDescription->nframes);
1.241 + return mDescription->frames[aIndex];
1.242 + }
1.243 +
1.244 + unsigned NumFrames()
1.245 + {
1.246 + return mDescription->nframes;
1.247 + }
1.248 +
1.249 +private:
1.250 + JS::StackDescription* mDescription;
1.251 +};
1.252 +
1.253 +NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(StackDescriptionOwner, AddRef)
1.254 +NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(StackDescriptionOwner, Release)
1.255 +
1.256 +NS_IMPL_CYCLE_COLLECTION_CLASS(StackDescriptionOwner)
1.257 +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(StackDescriptionOwner)
1.258 + if (tmp->mDescription) {
1.259 + JS::FreeStackDescription(nullptr, tmp->mDescription);
1.260 + tmp->mDescription = nullptr;
1.261 + }
1.262 +NS_IMPL_CYCLE_COLLECTION_UNLINK_END
1.263 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(StackDescriptionOwner)
1.264 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
1.265 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
1.266 +NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(StackDescriptionOwner)
1.267 + JS::StackDescription* desc = tmp->mDescription;
1.268 + if (tmp->mDescription) {
1.269 + for (size_t i = 0; i < desc->nframes; ++i) {
1.270 + NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDescription->frames[i].markedLocation1());
1.271 + NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDescription->frames[i].markedLocation2());
1.272 + }
1.273 + }
1.274 +NS_IMPL_CYCLE_COLLECTION_TRACE_END
1.275 +
1.276 +class JSStackFrame : public nsIStackFrame
1.277 +{
1.278 +public:
1.279 + NS_DECL_CYCLE_COLLECTING_ISUPPORTS
1.280 + NS_DECL_CYCLE_COLLECTION_CLASS(JSStackFrame)
1.281 + NS_DECL_NSISTACKFRAME
1.282 +
1.283 + // A null aStackDescription or an aIndex that's out of range for the
1.284 + // number of frames aStackDescription has will mean that the
1.285 + // JSStackFrame will never look at the stack description. Instead,
1.286 + // it is expected to be initialized by the caller as needed.
1.287 + JSStackFrame(StackDescriptionOwner* aStackDescription, size_t aIndex);
1.288 + virtual ~JSStackFrame();
1.289 +
1.290 + static already_AddRefed<nsIStackFrame>
1.291 + CreateStack(JSContext* aCx, int32_t aMaxDepth = -1);
1.292 + static already_AddRefed<nsIStackFrame>
1.293 + CreateStackFrameLocation(uint32_t aLanguage,
1.294 + const char* aFilename,
1.295 + const char* aFunctionName,
1.296 + int32_t aLineNumber,
1.297 + nsIStackFrame* aCaller);
1.298 +
1.299 +private:
1.300 + bool IsJSFrame() const {
1.301 + return mLanguage == nsIProgrammingLanguage::JAVASCRIPT;
1.302 + }
1.303 +
1.304 + int32_t GetLineno();
1.305 +
1.306 + nsRefPtr<StackDescriptionOwner> mStackDescription;
1.307 + nsCOMPtr<nsIStackFrame> mCaller;
1.308 +
1.309 + // Cached values
1.310 + nsString mFilename;
1.311 + nsString mFunname;
1.312 + int32_t mLineno;
1.313 + uint32_t mLanguage;
1.314 +
1.315 + size_t mIndex;
1.316 +
1.317 + bool mFilenameInitialized;
1.318 + bool mFunnameInitialized;
1.319 + bool mLinenoInitialized;
1.320 + bool mCallerInitialized;
1.321 +};
1.322 +
1.323 +JSStackFrame::JSStackFrame(StackDescriptionOwner* aStackDescription,
1.324 + size_t aIndex)
1.325 + : mLineno(0)
1.326 +{
1.327 + if (aStackDescription && aIndex < aStackDescription->NumFrames()) {
1.328 + mStackDescription = aStackDescription;
1.329 + mIndex = aIndex;
1.330 + mFilenameInitialized = false;
1.331 + mFunnameInitialized = false;
1.332 + mLinenoInitialized = false;
1.333 + mCallerInitialized = false;
1.334 + mLanguage = nsIProgrammingLanguage::JAVASCRIPT;
1.335 + } else {
1.336 + MOZ_ASSERT(!mStackDescription);
1.337 + mIndex = 0;
1.338 + mFilenameInitialized = true;
1.339 + mFunnameInitialized = true;
1.340 + mLinenoInitialized = true;
1.341 + mCallerInitialized = true;
1.342 + mLanguage = nsIProgrammingLanguage::UNKNOWN;
1.343 + }
1.344 +}
1.345 +
1.346 +JSStackFrame::~JSStackFrame()
1.347 +{
1.348 +}
1.349 +
1.350 +NS_IMPL_CYCLE_COLLECTION(JSStackFrame, mStackDescription, mCaller)
1.351 +
1.352 +NS_IMPL_CYCLE_COLLECTING_ADDREF(JSStackFrame)
1.353 +NS_IMPL_CYCLE_COLLECTING_RELEASE(JSStackFrame)
1.354 +
1.355 +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(JSStackFrame)
1.356 + NS_INTERFACE_MAP_ENTRY(nsIStackFrame)
1.357 + NS_INTERFACE_MAP_ENTRY(nsISupports)
1.358 +NS_INTERFACE_MAP_END
1.359 +
1.360 +/* readonly attribute uint32_t language; */
1.361 +NS_IMETHODIMP JSStackFrame::GetLanguage(uint32_t* aLanguage)
1.362 +{
1.363 + *aLanguage = mLanguage;
1.364 + return NS_OK;
1.365 +}
1.366 +
1.367 +/* readonly attribute string languageName; */
1.368 +NS_IMETHODIMP JSStackFrame::GetLanguageName(nsACString& aLanguageName)
1.369 +{
1.370 + static const char js[] = "JavaScript";
1.371 + static const char cpp[] = "C++";
1.372 +
1.373 + if (IsJSFrame()) {
1.374 + aLanguageName.AssignASCII(js);
1.375 + } else {
1.376 + aLanguageName.AssignASCII(cpp);
1.377 + }
1.378 +
1.379 + return NS_OK;
1.380 +}
1.381 +
1.382 +/* readonly attribute AString filename; */
1.383 +NS_IMETHODIMP JSStackFrame::GetFilename(nsAString& aFilename)
1.384 +{
1.385 + if (!mFilenameInitialized) {
1.386 + JS::FrameDescription& desc = mStackDescription->FrameAt(mIndex);
1.387 + if (const char *filename = desc.filename()) {
1.388 + CopyUTF8toUTF16(filename, mFilename);
1.389 + }
1.390 + mFilenameInitialized = true;
1.391 + }
1.392 +
1.393 + // The filename must be set to null if empty.
1.394 + if (mFilename.IsEmpty()) {
1.395 + aFilename.SetIsVoid(true);
1.396 + } else {
1.397 + aFilename.Assign(mFilename);
1.398 + }
1.399 +
1.400 + return NS_OK;
1.401 +}
1.402 +
1.403 +/* readonly attribute AString name; */
1.404 +NS_IMETHODIMP JSStackFrame::GetName(nsAString& aFunction)
1.405 +{
1.406 + if (!mFunnameInitialized) {
1.407 + JS::FrameDescription& desc = mStackDescription->FrameAt(mIndex);
1.408 + if (JSFlatString *name = desc.funDisplayName()) {
1.409 + mFunname.Assign(JS_GetFlatStringChars(name),
1.410 + // XXXbz Can't JS_GetStringLength on JSFlatString!
1.411 + JS_GetStringLength(JS_FORGET_STRING_FLATNESS(name)));
1.412 + }
1.413 + mFunnameInitialized = true;
1.414 + }
1.415 +
1.416 + // The function name must be set to null if empty.
1.417 + if (mFunname.IsEmpty()) {
1.418 + aFunction.SetIsVoid(true);
1.419 + } else {
1.420 + aFunction.Assign(mFunname);
1.421 + }
1.422 +
1.423 + return NS_OK;
1.424 +}
1.425 +
1.426 +int32_t
1.427 +JSStackFrame::GetLineno()
1.428 +{
1.429 + if (!mLinenoInitialized) {
1.430 + JS::FrameDescription& desc = mStackDescription->FrameAt(mIndex);
1.431 + mLineno = desc.lineno();
1.432 + mLinenoInitialized = true;
1.433 + }
1.434 +
1.435 + return mLineno;
1.436 +}
1.437 +
1.438 +/* readonly attribute int32_t lineNumber; */
1.439 +NS_IMETHODIMP JSStackFrame::GetLineNumber(int32_t* aLineNumber)
1.440 +{
1.441 + *aLineNumber = GetLineno();
1.442 + return NS_OK;
1.443 +}
1.444 +
1.445 +/* readonly attribute AUTF8String sourceLine; */
1.446 +NS_IMETHODIMP JSStackFrame::GetSourceLine(nsACString& aSourceLine)
1.447 +{
1.448 + aSourceLine.Truncate();
1.449 + return NS_OK;
1.450 +}
1.451 +
1.452 +/* readonly attribute nsIStackFrame caller; */
1.453 +NS_IMETHODIMP JSStackFrame::GetCaller(nsIStackFrame** aCaller)
1.454 +{
1.455 + if (!mCallerInitialized) {
1.456 + mCaller = new JSStackFrame(mStackDescription, mIndex+1);
1.457 + mCallerInitialized = true;
1.458 + }
1.459 + NS_IF_ADDREF(*aCaller = mCaller);
1.460 + return NS_OK;
1.461 +}
1.462 +
1.463 +/* AUTF8String toString (); */
1.464 +NS_IMETHODIMP JSStackFrame::ToString(nsACString& _retval)
1.465 +{
1.466 + _retval.Truncate();
1.467 +
1.468 + const char* frametype = IsJSFrame() ? "JS" : "native";
1.469 +
1.470 + nsString filename;
1.471 + nsresult rv = GetFilename(filename);
1.472 + NS_ENSURE_SUCCESS(rv, rv);
1.473 +
1.474 + if (filename.IsEmpty()) {
1.475 + filename.AssignLiteral("<unknown filename>");
1.476 + }
1.477 +
1.478 + nsString funname;
1.479 + rv = GetName(funname);
1.480 + NS_ENSURE_SUCCESS(rv, rv);
1.481 +
1.482 + if (funname.IsEmpty()) {
1.483 + funname.AssignLiteral("<TOP_LEVEL>");
1.484 + }
1.485 + static const char format[] = "%s frame :: %s :: %s :: line %d";
1.486 + _retval.AppendPrintf(format, frametype,
1.487 + NS_ConvertUTF16toUTF8(filename).get(),
1.488 + NS_ConvertUTF16toUTF8(funname).get(),
1.489 + GetLineno());
1.490 + return NS_OK;
1.491 +}
1.492 +
1.493 +/* static */ already_AddRefed<nsIStackFrame>
1.494 +JSStackFrame::CreateStack(JSContext* aCx, int32_t aMaxDepth)
1.495 +{
1.496 + static const unsigned MAX_FRAMES = 100;
1.497 + if (aMaxDepth < 0) {
1.498 + aMaxDepth = MAX_FRAMES;
1.499 + }
1.500 +
1.501 + JS::StackDescription* desc = JS::DescribeStack(aCx, aMaxDepth);
1.502 + if (!desc) {
1.503 + return nullptr;
1.504 + }
1.505 +
1.506 + nsRefPtr<StackDescriptionOwner> descOwner = new StackDescriptionOwner(desc);
1.507 +
1.508 + nsRefPtr<JSStackFrame> first = new JSStackFrame(descOwner, 0);
1.509 + return first.forget();
1.510 +}
1.511 +
1.512 +/* static */ already_AddRefed<nsIStackFrame>
1.513 +JSStackFrame::CreateStackFrameLocation(uint32_t aLanguage,
1.514 + const char* aFilename,
1.515 + const char* aFunctionName,
1.516 + int32_t aLineNumber,
1.517 + nsIStackFrame* aCaller)
1.518 +{
1.519 + nsRefPtr<JSStackFrame> self = new JSStackFrame(nullptr, 0);
1.520 +
1.521 + self->mLanguage = aLanguage;
1.522 + self->mLineno = aLineNumber;
1.523 + CopyUTF8toUTF16(aFilename, self->mFilename);
1.524 + CopyUTF8toUTF16(aFunctionName, self->mFunname);
1.525 +
1.526 + self->mCaller = aCaller;
1.527 +
1.528 + return self.forget();
1.529 +}
1.530 +
1.531 +already_AddRefed<nsIStackFrame>
1.532 +CreateStack(JSContext* aCx, int32_t aMaxDepth)
1.533 +{
1.534 + return JSStackFrame::CreateStack(aCx, aMaxDepth);
1.535 +}
1.536 +
1.537 +already_AddRefed<nsIStackFrame>
1.538 +CreateStackFrameLocation(uint32_t aLanguage,
1.539 + const char* aFilename,
1.540 + const char* aFunctionName,
1.541 + int32_t aLineNumber,
1.542 + nsIStackFrame* aCaller)
1.543 +{
1.544 + return JSStackFrame::CreateStackFrameLocation(aLanguage, aFilename,
1.545 + aFunctionName, aLineNumber,
1.546 + aCaller);
1.547 +}
1.548 +
1.549 +} // namespace exceptions
1.550 +} // namespace dom
1.551 +} // namespace mozilla
