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n-api: add napi_fatal_exception

Add function to trigger and uncaught exception.
Useful if an async callback throws an exception with
no way to recover.

Backport-PR-URL: #19447
PR-URL: #19337
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
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mafintosh authored and MylesBorins committed Mar 14, 2018
1 parent eb29266 commit 49cd4fad892c2d85756338bb09b718483fee5bad
@@ -539,6 +539,20 @@ This API returns true if an exception is pending.

This API can be called even if there is a pending JavaScript exception.

#### napi_fatal_exception
<!-- YAML
added: REPLACEME
-->
```C
napi_status napi_fatal_exception(napi_env env, napi_value err);
```

- `[in] env`: The environment that the API is invoked under.
- `[in] err`: The error you want to pass to `uncaughtException`.

Trigger an `uncaughtException` in JavaScript. Useful if an async
callback throws an exception with no way to recover.

### Fatal Errors

In the event of an unrecoverable error in a native module, a fatal error can be
@@ -293,6 +293,13 @@ v8::Local<v8::Value> V8LocalValueFromJsValue(napi_value v) {
return local;
}

static inline void trigger_fatal_exception(
napi_env env, v8::Local<v8::Value> local_err) {
v8::Local<v8::Message> local_msg =
v8::Exception::CreateMessage(env->isolate, local_err);
node::FatalException(env->isolate, local_err, local_msg);
}

static inline napi_status V8NameFromPropertyDescriptor(napi_env env,
const napi_property_descriptor* p,
v8::Local<v8::Name>* result) {
@@ -967,6 +974,16 @@ napi_status napi_get_last_error_info(napi_env env,
return napi_ok;
}

napi_status napi_fatal_exception(napi_env env, napi_value err) {
NAPI_PREAMBLE(env);
CHECK_ARG(env, err);

v8::Local<v8::Value> local_err = v8impl::V8LocalValueFromJsValue(err);
v8impl::trigger_fatal_exception(env, local_err);

return napi_clear_last_error(env);
}

NAPI_NO_RETURN void napi_fatal_error(const char* location,
size_t location_len,
const char* message,
@@ -3457,10 +3474,9 @@ class Work : public node::AsyncResource {
// report it as a fatal exception. (There is no JavaScript on the
// callstack that can possibly handle it.)
if (!env->last_exception.IsEmpty()) {
v8::TryCatch try_catch(env->isolate);
env->isolate->ThrowException(
v8::Local<v8::Value>::New(env->isolate, env->last_exception));
node::FatalException(env->isolate, try_catch);
v8::Local<v8::Value> local_err = v8::Local<v8::Value>::New(
env->isolate, env->last_exception);
v8impl::trigger_fatal_exception(env, local_err);
}
}
}
@@ -103,6 +103,8 @@ NAPI_EXTERN napi_status
napi_get_last_error_info(napi_env env,
const napi_extended_error_info** result);

NAPI_EXTERN napi_status napi_fatal_exception(napi_env env, napi_value err);

NAPI_EXTERN NAPI_NO_RETURN void napi_fatal_error(const char* location,
size_t location_len,
const char* message,
@@ -118,6 +118,11 @@ void GetSockOrPeerName(const v8::FunctionCallbackInfo<v8::Value>& args) {
args.GetReturnValue().Set(err);
}

void FatalException(v8::Isolate* isolate,
v8::Local<v8::Value> error,
v8::Local<v8::Message> message);


void SignalExit(int signo);
#ifdef __POSIX__
void RegisterSignalHandler(int signal,
@@ -0,0 +1,18 @@
'use strict';
const common = require('../../common');
const assert = require('assert');
const test_async = require(`./build/${common.buildType}/test_async`);

process.on('uncaughtException', common.mustCall(function(err) {
try {
throw new Error('should not fail');
} catch (err) {
assert.strictEqual(err.message, 'should not fail');
}
assert.strictEqual(err.message, 'uncaught');
}));

// Successful async execution and completion callback.
test_async.Test(5, {}, common.mustCall(function() {
throw new Error('uncaught');
}));
@@ -0,0 +1,8 @@
{
"targets": [
{
"target_name": "test_fatal_exception",
"sources": [ "test_fatal_exception.c" ]
}
]
}
@@ -0,0 +1,11 @@
'use strict';
const common = require('../../common');
const assert = require('assert');
const test_fatal = require(`./build/${common.buildType}/test_fatal_exception`);

process.on('uncaughtException', common.mustCall(function(err) {
assert.strictEqual(err.message, 'fatal error');
}));

const err = new Error('fatal error');
test_fatal.Test(err);
@@ -0,0 +1,26 @@
#include <node_api.h>
#include "../common.h"

napi_value Test(napi_env env, napi_callback_info info) {
napi_value err;
size_t argc = 1;

NAPI_CALL(env, napi_get_cb_info(env, info, &argc, &err, NULL, NULL));

NAPI_CALL(env, napi_fatal_exception(env, err));

return NULL;
}

napi_value Init(napi_env env, napi_value exports) {
napi_property_descriptor properties[] = {
DECLARE_NAPI_PROPERTY("Test", Test),
};

NAPI_CALL(env, napi_define_properties(
env, exports, sizeof(properties) / sizeof(*properties), properties));

return exports;
}

NAPI_MODULE(NODE_GYP_MODULE_NAME, Init)

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