gecko-dev/dom/bindings/Exceptions.cpp

632 lines
17 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
#include "mozilla/dom/Exceptions.h"
#include "js/GCAPI.h"
#include "js/OldDebugAPI.h"
#include "jsapi.h"
#include "jsprf.h"
#include "mozilla/CycleCollectedJSRuntime.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/ScriptSettings.h"
#include "nsPIDOMWindow.h"
#include "nsServiceManagerUtils.h"
#include "nsThreadUtils.h"
#include "XPCWrapper.h"
#include "WorkerPrivate.h"
#include "nsContentUtils.h"
namespace mozilla {
namespace dom {
bool
ThrowExceptionObject(JSContext* aCx, nsIException* aException)
{
// See if we really have an Exception.
nsCOMPtr<Exception> exception = do_QueryInterface(aException);
if (exception) {
return ThrowExceptionObject(aCx, exception);
}
// We only have an nsIException (probably an XPCWrappedJS). Fall back on old
// wrapping.
MOZ_ASSERT(NS_IsMainThread());
JS::Rooted<JSObject*> glob(aCx, JS::CurrentGlobalOrNull(aCx));
if (!glob) {
// XXXbz Can this really be null here?
return false;
}
JS::Rooted<JS::Value> val(aCx);
if (!WrapObject(aCx, aException, &NS_GET_IID(nsIException), &val)) {
return false;
}
JS_SetPendingException(aCx, val);
return true;
}
bool
ThrowExceptionObject(JSContext* aCx, Exception* aException)
{
JS::Rooted<JS::Value> thrown(aCx);
// If we stored the original thrown JS value in the exception
// (see XPCConvert::ConstructException) and we are in a web context
// (i.e., not chrome), rethrow the original value. This only applies to JS
// implemented components so we only need to check for this on the main
// thread.
if (NS_IsMainThread() && !nsContentUtils::IsCallerChrome() &&
aException->StealJSVal(thrown.address())) {
if (!JS_WrapValue(aCx, &thrown)) {
return false;
}
JS_SetPendingException(aCx, thrown);
return true;
}
JS::Rooted<JSObject*> glob(aCx, JS::CurrentGlobalOrNull(aCx));
if (!glob) {
// XXXbz Can this actually be null here?
return false;
}
if (!WrapNewBindingObject(aCx, aException, &thrown)) {
return false;
}
JS_SetPendingException(aCx, thrown);
return true;
}
bool
Throw(JSContext* aCx, nsresult aRv, const char* aMessage)
{
if (JS_IsExceptionPending(aCx)) {
// Don't clobber the existing exception.
return false;
}
CycleCollectedJSRuntime* runtime = CycleCollectedJSRuntime::Get();
nsCOMPtr<nsIException> existingException = runtime->GetPendingException();
if (existingException) {
nsresult nr;
if (NS_SUCCEEDED(existingException->GetResult(&nr)) &&
aRv == nr) {
// Reuse the existing exception.
// Clear pending exception
runtime->SetPendingException(nullptr);
if (!ThrowExceptionObject(aCx, existingException)) {
// If we weren't able to throw an exception we're
// most likely out of memory
JS_ReportOutOfMemory(aCx);
}
return false;
}
}
nsRefPtr<Exception> finalException = CreateException(aCx, aRv, aMessage);
MOZ_ASSERT(finalException);
if (!ThrowExceptionObject(aCx, finalException)) {
// If we weren't able to throw an exception we're
// most likely out of memory
JS_ReportOutOfMemory(aCx);
}
return false;
}
void
ThrowAndReport(nsPIDOMWindow* aWindow, nsresult aRv, const char* aMessage)
{
AutoJSAPI jsapi;
if (NS_WARN_IF(!jsapi.InitWithLegacyErrorReporting(aWindow))) {
return;
}
Throw(jsapi.cx(), aRv, aMessage);
(void) JS_ReportPendingException(jsapi.cx());
}
already_AddRefed<Exception>
CreateException(JSContext* aCx, nsresult aRv, const char* aMessage)
{
// Do we use DOM exceptions for this error code?
switch (NS_ERROR_GET_MODULE(aRv)) {
case NS_ERROR_MODULE_DOM:
case NS_ERROR_MODULE_SVG:
case NS_ERROR_MODULE_DOM_XPATH:
case NS_ERROR_MODULE_DOM_INDEXEDDB:
case NS_ERROR_MODULE_DOM_FILEHANDLE:
case NS_ERROR_MODULE_DOM_BLUETOOTH:
return DOMException::Create(aRv);
default:
break;
}
// If not, use the default.
// aMessage can be null, so we can't use nsDependentCString on it.
nsRefPtr<Exception> exception =
new Exception(nsCString(aMessage), aRv,
EmptyCString(), nullptr, nullptr);
return exception.forget();
}
already_AddRefed<nsIStackFrame>
GetCurrentJSStack()
{
// is there a current context available?
JSContext* cx = nullptr;
if (NS_IsMainThread()) {
MOZ_ASSERT(nsContentUtils::XPConnect());
cx = nsContentUtils::GetCurrentJSContext();
} else {
cx = workers::GetCurrentThreadJSContext();
}
if (!cx) {
return nullptr;
}
nsCOMPtr<nsIStackFrame> stack = exceptions::CreateStack(cx);
if (!stack) {
return nullptr;
}
// Note that CreateStack only returns JS frames, so we're done here.
return stack.forget();
}
namespace exceptions {
class StackFrame : public nsIStackFrame
{
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS(StackFrame)
NS_DECL_NSISTACKFRAME
StackFrame(uint32_t aLanguage,
const char* aFilename,
const char* aFunctionName,
int32_t aLineNumber,
nsIStackFrame* aCaller);
StackFrame()
: mLineno(0)
, mLanguage(nsIProgrammingLanguage::UNKNOWN)
{
}
static already_AddRefed<nsIStackFrame>
CreateStackFrameLocation(uint32_t aLanguage,
const char* aFilename,
const char* aFunctionName,
int32_t aLineNumber,
nsIStackFrame* aCaller);
protected:
virtual ~StackFrame();
virtual bool IsJSFrame() const
{
return false;
}
virtual nsresult GetLineno(int32_t* aLineNo)
{
*aLineNo = mLineno;
return NS_OK;
}
nsCOMPtr<nsIStackFrame> mCaller;
nsString mFilename;
nsString mFunname;
int32_t mLineno;
uint32_t mLanguage;
};
StackFrame::StackFrame(uint32_t aLanguage,
const char* aFilename,
const char* aFunctionName,
int32_t aLineNumber,
nsIStackFrame* aCaller)
: mCaller(aCaller)
, mLineno(aLineNumber)
, mLanguage(aLanguage)
{
CopyUTF8toUTF16(aFilename, mFilename);
CopyUTF8toUTF16(aFunctionName, mFunname);
}
StackFrame::~StackFrame()
{
}
NS_IMPL_CYCLE_COLLECTION(StackFrame, mCaller)
NS_IMPL_CYCLE_COLLECTING_ADDREF(StackFrame)
NS_IMPL_CYCLE_COLLECTING_RELEASE(StackFrame)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(StackFrame)
NS_INTERFACE_MAP_ENTRY(nsIStackFrame)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
class JSStackFrame : public StackFrame
{
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(JSStackFrame,
StackFrame)
// aStack must not be null.
JSStackFrame(JS::Handle<JSObject*> aStack);
static already_AddRefed<nsIStackFrame>
CreateStack(JSContext* aCx, int32_t aMaxDepth = -1);
NS_IMETHOD GetLanguageName(nsACString& aLanguageName) MOZ_OVERRIDE;
NS_IMETHOD GetFilename(nsAString& aFilename) MOZ_OVERRIDE;
NS_IMETHOD GetName(nsAString& aFunction) MOZ_OVERRIDE;
NS_IMETHOD GetCaller(nsIStackFrame** aCaller) MOZ_OVERRIDE;
NS_IMETHOD GetFormattedStack(nsAString& aStack) MOZ_OVERRIDE;
protected:
virtual bool IsJSFrame() const MOZ_OVERRIDE {
return true;
}
virtual nsresult GetLineno(int32_t* aLineNo) MOZ_OVERRIDE;
private:
virtual ~JSStackFrame();
JS::Heap<JSObject*> mStack;
nsString mFormattedStack;
bool mFilenameInitialized;
bool mFunnameInitialized;
bool mLinenoInitialized;
bool mCallerInitialized;
bool mFormattedStackInitialized;
};
JSStackFrame::JSStackFrame(JS::Handle<JSObject*> aStack)
: mStack(aStack)
, mFilenameInitialized(false)
, mFunnameInitialized(false)
, mLinenoInitialized(false)
, mCallerInitialized(false)
, mFormattedStackInitialized(false)
{
MOZ_ASSERT(mStack);
mozilla::HoldJSObjects(this);
mLineno = 0;
mLanguage = nsIProgrammingLanguage::JAVASCRIPT;
}
JSStackFrame::~JSStackFrame()
{
mozilla::DropJSObjects(this);
}
NS_IMPL_CYCLE_COLLECTION_CLASS(JSStackFrame)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(JSStackFrame, StackFrame)
tmp->mStack = nullptr;
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(JSStackFrame, StackFrame)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(JSStackFrame, StackFrame)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mStack)
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_ADDREF_INHERITED(JSStackFrame, StackFrame)
NS_IMPL_RELEASE_INHERITED(JSStackFrame, StackFrame)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(JSStackFrame)
NS_INTERFACE_MAP_END_INHERITING(StackFrame)
/* readonly attribute uint32_t language; */
NS_IMETHODIMP StackFrame::GetLanguage(uint32_t* aLanguage)
{
*aLanguage = mLanguage;
return NS_OK;
}
/* readonly attribute string languageName; */
NS_IMETHODIMP StackFrame::GetLanguageName(nsACString& aLanguageName)
{
aLanguageName.AssignLiteral("C++");
return NS_OK;
}
NS_IMETHODIMP JSStackFrame::GetLanguageName(nsACString& aLanguageName)
{
aLanguageName.AssignLiteral("JavaScript");
return NS_OK;
}
/* readonly attribute AString filename; */
NS_IMETHODIMP JSStackFrame::GetFilename(nsAString& aFilename)
{
// We can get called after unlink; in that case we can't do much
// about producing a useful value.
if (!mFilenameInitialized && mStack) {
ThreadsafeAutoJSContext cx;
JS::Rooted<JSObject*> stack(cx, mStack);
JS::ExposeObjectToActiveJS(mStack);
JSAutoCompartment ac(cx, stack);
JS::Rooted<JS::Value> filenameVal(cx);
if (!JS_GetProperty(cx, stack, "source", &filenameVal) ||
!filenameVal.isString()) {
return NS_ERROR_UNEXPECTED;
}
nsAutoJSString str;
if (!str.init(cx, filenameVal.toString())) {
return NS_ERROR_OUT_OF_MEMORY;
}
mFilename = str;
mFilenameInitialized = true;
}
return StackFrame::GetFilename(aFilename);
}
NS_IMETHODIMP StackFrame::GetFilename(nsAString& aFilename)
{
// The filename must be set to null if empty.
if (mFilename.IsEmpty()) {
aFilename.SetIsVoid(true);
} else {
aFilename.Assign(mFilename);
}
return NS_OK;
}
/* readonly attribute AString name; */
NS_IMETHODIMP JSStackFrame::GetName(nsAString& aFunction)
{
// We can get called after unlink; in that case we can't do much
// about producing a useful value.
if (!mFunnameInitialized && mStack) {
ThreadsafeAutoJSContext cx;
JS::Rooted<JSObject*> stack(cx, mStack);
JS::ExposeObjectToActiveJS(mStack);
JSAutoCompartment ac(cx, stack);
JS::Rooted<JS::Value> nameVal(cx);
// functionDisplayName can be null
if (!JS_GetProperty(cx, stack, "functionDisplayName", &nameVal) ||
(!nameVal.isString() && !nameVal.isNull())) {
return NS_ERROR_UNEXPECTED;
}
if (nameVal.isString()) {
nsAutoJSString str;
if (!str.init(cx, nameVal.toString())) {
return NS_ERROR_OUT_OF_MEMORY;
}
mFunname = str;
}
mFunnameInitialized = true;
}
return StackFrame::GetName(aFunction);
}
NS_IMETHODIMP StackFrame::GetName(nsAString& aFunction)
{
// The function name must be set to null if empty.
if (mFunname.IsEmpty()) {
aFunction.SetIsVoid(true);
} else {
aFunction.Assign(mFunname);
}
return NS_OK;
}
// virtual
nsresult
JSStackFrame::GetLineno(int32_t* aLineNo)
{
// We can get called after unlink; in that case we can't do much
// about producing a useful value.
if (!mLinenoInitialized && mStack) {
ThreadsafeAutoJSContext cx;
JS::Rooted<JSObject*> stack(cx, mStack);
JS::ExposeObjectToActiveJS(mStack);
JSAutoCompartment ac(cx, stack);
JS::Rooted<JS::Value> lineVal(cx);
if (!JS_GetProperty(cx, stack, "line", &lineVal) ||
!lineVal.isNumber()) {
return NS_ERROR_UNEXPECTED;
}
mLineno = lineVal.toNumber();
mLinenoInitialized = true;
}
return StackFrame::GetLineno(aLineNo);
}
/* readonly attribute int32_t lineNumber; */
NS_IMETHODIMP StackFrame::GetLineNumber(int32_t* aLineNumber)
{
return GetLineno(aLineNumber);
}
/* readonly attribute AUTF8String sourceLine; */
NS_IMETHODIMP StackFrame::GetSourceLine(nsACString& aSourceLine)
{
aSourceLine.Truncate();
return NS_OK;
}
/* readonly attribute nsIStackFrame caller; */
NS_IMETHODIMP JSStackFrame::GetCaller(nsIStackFrame** aCaller)
{
// We can get called after unlink; in that case we can't do much
// about producing a useful value.
if (!mCallerInitialized && mStack) {
ThreadsafeAutoJSContext cx;
JS::Rooted<JSObject*> stack(cx, mStack);
JS::ExposeObjectToActiveJS(mStack);
JSAutoCompartment ac(cx, stack);
JS::Rooted<JS::Value> callerVal(cx);
if (!JS_GetProperty(cx, stack, "parent", &callerVal) ||
!callerVal.isObjectOrNull()) {
return NS_ERROR_UNEXPECTED;
}
if (callerVal.isObject()) {
JS::Rooted<JSObject*> caller(cx, &callerVal.toObject());
mCaller = new JSStackFrame(caller);
} else {
// Do we really need this dummy frame? If so, we should document why... I
// guess for symmetry with the "nothing on the stack" case, which returns
// a single dummy frame?
mCaller = new StackFrame();
}
mCallerInitialized = true;
}
return StackFrame::GetCaller(aCaller);
}
NS_IMETHODIMP StackFrame::GetCaller(nsIStackFrame** aCaller)
{
NS_IF_ADDREF(*aCaller = mCaller);
return NS_OK;
}
NS_IMETHODIMP JSStackFrame::GetFormattedStack(nsAString& aStack)
{
// We can get called after unlink; in that case we can't do much
// about producing a useful value.
if (!mFormattedStackInitialized && mStack) {
ThreadsafeAutoJSContext cx;
JS::Rooted<JS::Value> stack(cx, JS::ObjectValue(*mStack));
JS::ExposeObjectToActiveJS(mStack);
JSAutoCompartment ac(cx, mStack);
JS::Rooted<JSString*> formattedStack(cx, JS::ToString(cx, stack));
if (!formattedStack) {
return NS_ERROR_UNEXPECTED;
}
nsAutoJSString str;
if (!str.init(cx, formattedStack)) {
return NS_ERROR_OUT_OF_MEMORY;
}
mFormattedStack = str;
mFormattedStackInitialized = true;
}
aStack = mFormattedStack;
return NS_OK;
}
NS_IMETHODIMP StackFrame::GetFormattedStack(nsAString& aStack)
{
aStack.Truncate();
return NS_OK;
}
/* AUTF8String toString (); */
NS_IMETHODIMP StackFrame::ToString(nsACString& _retval)
{
_retval.Truncate();
const char* frametype = IsJSFrame() ? "JS" : "native";
nsString filename;
nsresult rv = GetFilename(filename);
NS_ENSURE_SUCCESS(rv, rv);
if (filename.IsEmpty()) {
filename.AssignLiteral("<unknown filename>");
}
nsString funname;
rv = GetName(funname);
NS_ENSURE_SUCCESS(rv, rv);
if (funname.IsEmpty()) {
funname.AssignLiteral("<TOP_LEVEL>");
}
int32_t lineno;
rv = GetLineno(&lineno);
NS_ENSURE_SUCCESS(rv, rv);
static const char format[] = "%s frame :: %s :: %s :: line %d";
_retval.AppendPrintf(format, frametype,
NS_ConvertUTF16toUTF8(filename).get(),
NS_ConvertUTF16toUTF8(funname).get(),
lineno);
return NS_OK;
}
/* static */ already_AddRefed<nsIStackFrame>
JSStackFrame::CreateStack(JSContext* aCx, int32_t aMaxDepth)
{
static const unsigned MAX_FRAMES = 100;
if (aMaxDepth < 0) {
aMaxDepth = MAX_FRAMES;
}
JS::Rooted<JSObject*> stack(aCx);
if (!JS::CaptureCurrentStack(aCx, &stack, aMaxDepth)) {
return nullptr;
}
nsCOMPtr<nsIStackFrame> first;
if (!stack) {
first = new StackFrame();
} else {
first = new JSStackFrame(stack);
}
return first.forget();
}
/* static */ already_AddRefed<nsIStackFrame>
StackFrame::CreateStackFrameLocation(uint32_t aLanguage,
const char* aFilename,
const char* aFunctionName,
int32_t aLineNumber,
nsIStackFrame* aCaller)
{
nsRefPtr<StackFrame> self =
new StackFrame(aLanguage, aFilename, aFunctionName, aLineNumber, aCaller);
return self.forget();
}
already_AddRefed<nsIStackFrame>
CreateStack(JSContext* aCx, int32_t aMaxDepth)
{
return JSStackFrame::CreateStack(aCx, aMaxDepth);
}
already_AddRefed<nsIStackFrame>
CreateStackFrameLocation(uint32_t aLanguage,
const char* aFilename,
const char* aFunctionName,
int32_t aLineNumber,
nsIStackFrame* aCaller)
{
return StackFrame::CreateStackFrameLocation(aLanguage, aFilename,
aFunctionName, aLineNumber,
aCaller);
}
} // namespace exceptions
} // namespace dom
} // namespace mozilla