nsresult
nsJSUtils::EvaluateString(JSContext* aCx,
JS::SourceBufferHolder& aSrcBuf,
JS::Handle<JSObject*> aEvaluationGlobal,
JS::CompileOptions& aCompileOptions,
const EvaluateOptions& aEvaluateOptions,
JS::MutableHandle<JS::Value> aRetValue,
void **aOffThreadToken)
{
PROFILER_LABEL("nsJSUtils", "EvaluateString",
js::ProfileEntry::Category::JS);
MOZ_ASSERT(JS::ContextOptionsRef(aCx).autoJSAPIOwnsErrorReporting(),
"Caller must own error reporting");
MOZ_ASSERT_IF(aCompileOptions.versionSet,
aCompileOptions.version != JSVERSION_UNKNOWN);
MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
MOZ_ASSERT(aSrcBuf.get());
MOZ_ASSERT(js::GetGlobalForObjectCrossCompartment(aEvaluationGlobal) ==
aEvaluationGlobal);
MOZ_ASSERT_IF(aOffThreadToken, aCompileOptions.noScriptRval);
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(nsContentUtils::IsInMicroTask());
// Unfortunately, the JS engine actually compiles scripts with a return value
// in a different, less efficient way. Furthermore, it can't JIT them in many
// cases. So we need to be explicitly told whether the caller cares about the
// return value. Callers can do this by calling the other overload of
// EvaluateString() which calls this function with
// aCompileOptions.noScriptRval set to true.
aRetValue.setUndefined();
nsresult rv = NS_OK;
nsIScriptSecurityManager* ssm = nsContentUtils::GetSecurityManager();
NS_ENSURE_TRUE(ssm->ScriptAllowed(aEvaluationGlobal), NS_OK);
bool ok = true;
// Scope the JSAutoCompartment so that we can later wrap the return value
// into the caller's cx.
{
JSAutoCompartment ac(aCx, aEvaluationGlobal);
// Now make sure to wrap the scope chain into the right compartment.
JS::AutoObjectVector scopeChain(aCx);
if (!scopeChain.reserve(aEvaluateOptions.scopeChain.length())) {
return NS_ERROR_OUT_OF_MEMORY;
}
for (size_t i = 0; i < aEvaluateOptions.scopeChain.length(); ++i) {
JS::ExposeObjectToActiveJS(aEvaluateOptions.scopeChain[i]);
scopeChain.infallibleAppend(aEvaluateOptions.scopeChain[i]);
if (!JS_WrapObject(aCx, scopeChain[i])) {
ok = false;
break;
}
}
if (ok && aOffThreadToken) {
JS::Rooted<JSScript*>
script(aCx, JS::FinishOffThreadScript(aCx, JS_GetRuntime(aCx), *aOffThreadToken));
*aOffThreadToken = nullptr; // Mark the token as having been finished.
if (script) {
ok = JS_ExecuteScript(aCx, scopeChain, script);
} else {
ok = false;
}
} else if (ok) {
ok = JS::Evaluate(aCx, scopeChain, aCompileOptions, aSrcBuf, aRetValue);
}
}
if (!ok) {
if (JS_IsExceptionPending(aCx)) {
rv = NS_SUCCESS_DOM_SCRIPT_EVALUATION_THREW;
} else {
rv = NS_SUCCESS_DOM_SCRIPT_EVALUATION_THREW_UNCATCHABLE;
}
if (!aCompileOptions.noScriptRval) {
aRetValue.setUndefined();
}
}
// Wrap the return value into whatever compartment aCx was in.
if (ok && !aCompileOptions.noScriptRval) {
if (!JS_WrapValue(aCx, aRetValue)) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
return rv;
}
nsresult
nsJSUtils::EvaluateString(JSContext* aCx,
JS::SourceBufferHolder& aSrcBuf,
JS::Handle<JSObject*> aScopeObject,
JS::CompileOptions& aCompileOptions,
const EvaluateOptions& aEvaluateOptions,
JS::MutableHandle<JS::Value> aRetValue,
void **aOffThreadToken)
{
PROFILER_LABEL("nsJSUtils", "EvaluateString",
js::ProfileEntry::Category::JS);
MOZ_ASSERT_IF(aCompileOptions.versionSet,
aCompileOptions.version != JSVERSION_UNKNOWN);
MOZ_ASSERT_IF(aEvaluateOptions.coerceToString, aEvaluateOptions.needResult);
MOZ_ASSERT_IF(!aEvaluateOptions.reportUncaught, aEvaluateOptions.needResult);
MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
MOZ_ASSERT(aSrcBuf.get());
// Unfortunately, the JS engine actually compiles scripts with a return value
// in a different, less efficient way. Furthermore, it can't JIT them in many
// cases. So we need to be explicitly told whether the caller cares about the
// return value. Callers can do this by calling the other overload of
// EvaluateString() which calls this function with aEvaluateOptions.needResult
// set to false.
aRetValue.setUndefined();
JS::ExposeObjectToActiveJS(aScopeObject);
nsAutoMicroTask mt;
nsresult rv = NS_OK;
bool ok = false;
nsIScriptSecurityManager* ssm = nsContentUtils::GetSecurityManager();
NS_ENSURE_TRUE(ssm->ScriptAllowed(js::GetGlobalForObjectCrossCompartment(aScopeObject)), NS_OK);
mozilla::Maybe<AutoDontReportUncaught> dontReport;
if (!aEvaluateOptions.reportUncaught) {
// We need to prevent AutoLastFrameCheck from reporting and clearing
// any pending exceptions.
dontReport.emplace(aCx);
}
// Scope the JSAutoCompartment so that we can later wrap the return value
// into the caller's cx.
{
JSAutoCompartment ac(aCx, aScopeObject);
JS::Rooted<JSObject*> rootedScope(aCx, aScopeObject);
if (aOffThreadToken) {
JS::Rooted<JSScript*>
script(aCx, JS::FinishOffThreadScript(aCx, JS_GetRuntime(aCx), *aOffThreadToken));
*aOffThreadToken = nullptr; // Mark the token as having been finished.
if (script) {
if (aEvaluateOptions.needResult) {
ok = JS_ExecuteScript(aCx, rootedScope, script, aRetValue);
} else {
ok = JS_ExecuteScript(aCx, rootedScope, script);
}
} else {
ok = false;
}
} else {
if (aEvaluateOptions.needResult) {
ok = JS::Evaluate(aCx, rootedScope, aCompileOptions,
aSrcBuf, aRetValue);
} else {
ok = JS::Evaluate(aCx, rootedScope, aCompileOptions,
aSrcBuf);
}
}
if (ok && aEvaluateOptions.coerceToString && !aRetValue.isUndefined()) {
JS::Rooted<JS::Value> value(aCx, aRetValue);
JSString* str = JS::ToString(aCx, value);
ok = !!str;
aRetValue.set(ok ? JS::StringValue(str) : JS::UndefinedValue());
}
}
if (!ok) {
if (aEvaluateOptions.reportUncaught) {
ReportPendingException(aCx);
if (aEvaluateOptions.needResult) {
aRetValue.setUndefined();
}
} else {
rv = JS_IsExceptionPending(aCx) ? NS_ERROR_FAILURE
: NS_ERROR_OUT_OF_MEMORY;
JS::Rooted<JS::Value> exn(aCx);
JS_GetPendingException(aCx, &exn);
if (aEvaluateOptions.needResult) {
aRetValue.set(exn);
}
JS_ClearPendingException(aCx);
}
}
// Wrap the return value into whatever compartment aCx was in.
if (aEvaluateOptions.needResult) {
JS::Rooted<JS::Value> v(aCx, aRetValue);
if (!JS_WrapValue(aCx, &v)) {
return NS_ERROR_OUT_OF_MEMORY;
}
aRetValue.set(v);
}
return rv;
}