Segfault handler for Node.js

This is a part of Node3D project.


``
npm i -s segfault-raub
`

This module report debug information on process crash (and some other events).
It doesn't affect the performance while the program is running normally.

The module prints to both
STDERR and to the "segfault.log" file (if it exists inside "working directory").
If there is no such file, it
won't be created, so it is up to you if the log-file is needed.

> Note: this addon uses N-API, and therefore is ABI-compatible across different
Node.js versions. Addon binaries are precompiled and there is no compilation
step during the npm i command.

A zero-setup is available: just require the module and it comes pre-equipped with several
signal listeners enabled by default.

`js
require('segfault-raub');
`

> Note: if your project tree contains multiple versions of this module, the first one imported
will seize global['segfault-raub']. The rest of them will only re-export global['segfault-raub']
and WILL NOT import their own binaries.

---

If you want to use a custom location instead of "segfault.log", use:

`js
require('segfault-raub').setLogPath("C:/my/log/file.txt");
`

You must create this file first, it must be there when the crash happens.

See the TypeScript declarations with comments.

Configuring Signals

As listed below, some signals (platform specific) are enabled by default. But they can be
enabled/disabled manually:

Example:

`js
const {
setSignal,
EXCEPTION_ACCESS_VIOLATION, SIGSEGV,
EXCEPTION_BREAKPOINT, SIGTRAP,
} = require('segfault-raub');

setSignal(EXCEPTION_ACCESS_VIOLATION, false);
setSignal(SIGSEGV, false);

setSignal(EXCEPTION_BREAKPOINT, true);
setSignal(SIGTRAP, true);

// This enables capturing every signal on Windows.
setSignal(EXCEPTION_ALL, true);
`

On Windows, all the Unix signals are null, and the opposite is true.
Passing null as the first parameter to setSignal has no effect and is safe.

Demo Methods

These are be helpful to see how the signals are reported and if the log files are being written properly.

* causeSegfault - Causes a memory access violation.
* causeDivisionInt - Divides an integer by zero.
* causeOverflow - Runs infinite recursion (stack overflow).
* causeIllegal - Raises an "illegal instruction" exception.

Example:

`js
const { causeSegfault } = require('segfault-raub');
causeSegfault();
`

Windows Signals

| Signal | Enabled | Description |
| :--- | :---: | :--- |
| EXCEPTION_ALL | no | All of the below. |
| EXCEPTION_ACCESS_VIOLATION | yes | Memory access was denied. |
| EXCEPTION_ARRAY_BOUNDS_EXCEEDED | yes | Array was accessed with an illegal index. |
| EXCEPTION_INT_DIVIDE_BY_ZERO | yes | Attempt to divide by an integer divisor of 0. |
| EXCEPTION_ILLEGAL_INSTRUCTION | yes | Attempt to execute an illegal instruction. |
| EXCEPTION_NONCONTINUABLE_EXCEPTION | yes | Can't continue after an exception. |
| EXCEPTION_STACK_OVERFLOW | yes | The thread used up its stack. |
| EXCEPTION_INVALID_HANDLE | yes | An invalid handle was specified. |
| EXCEPTION_FLT_DIVIDE_BY_ZERO | no | Attempt to divide by a float divisor of 0.f. |
| EXCEPTION_DATATYPE_MISALIGNMENT | no | A datatype misalignment was detected. |
| EXCEPTION_BREAKPOINT | no | A Breakpoint has been reached. |
| EXCEPTION_SINGLE_STEP | no | Continue single-stepping execution. |
| EXCEPTION_FLT_DENORMAL_OPERAND | no | One of the operands is denormal. |
| EXCEPTION_FLT_INEXACT_RESULT | no | The result cannot be represented exactly. |
| EXCEPTION_FLT_INVALID_OPERATION | no | Floating-point invalid operation. |
| EXCEPTION_FLT_OVERFLOW | no | The exponent of operation is too large. |
| EXCEPTION_FLT_STACK_CHECK | no | The Stack gone bad after a float operation. |
| EXCEPTION_FLT_UNDERFLOW | no | The exponent of operation is too low. |
| EXCEPTION_INT_OVERFLOW | no | The result of operation is too large. |
| EXCEPTION_PRIV_INSTRUCTION | no | Operation is not allowed in current mode. |
| EXCEPTION_IN_PAGE_ERROR | no | Can't access a memory page. |
| EXCEPTION_INVALID_DISPOSITION | no | Invalid disposition returned. |
| EXCEPTION_GUARD_PAGE | no | Accessing PAGE_GUARD-allocated modifier. |

Unix Signals

| Signal | Handling | Enabled | Description |
| :--- | :---: | :---: | :--- |
| SIGABRT | A | yes | Process abort signal. |
| SIGFPE | A | yes | Erroneous arithmetic operation. |
| SIGSEGV | A | yes | Invalid memory reference. |
| SIGILL | A | yes | Illegal instruction. |
| SIGBUS | A | yes | Access to an undefined portion of a memory object. |
| SIGTERM | T | no | Termination signal. |
| SIGINT | T | no | Terminal interrupt signal. |
| SIGALRM | T | no | Alarm clock. |
| SIGCHLD | I | no | Child process terminated, stopped, or continued. |
| SIGCONT | C | no | Continue executing, if stopped. |
| SIGHUP | T | no | Hangup. |
| SIGKILL | T | no | Kill (cannot be caught or ignored). |
| SIGPIPE | T | no | Write on a pipe with no one to read it. |
| SIGQUIT | A | no | Terminal quit signal. |
| SIGSTOP | S | no | Stop executing (cannot be caught or ignored). |
| SIGTSTP | S | no | Terminal stop signal. |
| SIGTTIN | S | no | Background process attempting read. |
| SIGTTOU | S | no | Background process attempting write. |
| SIGUSR1 | T | no | User-defined signal 1. |
| SIGUSR2 | T | no | User-defined signal 2. |
| SIGPROF | T | no | Profiling timer expired. |
| SIGSYS | A | no | Bad system call. |
| SIGTRAP | A | no | Trace/breakpoint trap. |
| SIGURG | I | no | High bandwidth data is available at a socket. |
| SIGVTALRM | T | no | Virtual timer expired. |
| SIGXCPU | A | no | CPU time limit exceeded. |
| SIGXFSZ | A | no | File size limit exceeded. |

* T - Abnormal termination of the process.
* A - Abnormal termination of the process with additional actions.
* I - Ignore the signal.
* S - Stop the process.
* C - Continue the process, if it is stopped; otherwise, ignore the signal.

Legal notice

This package is derived from segfault-handler.
The original licensing rules apply, see LICENSE_node-segfault-handler`.

Also this project uses callstack walker
which is licensed under BSD-2 Clause.

The rest of this package (the newly introduced files) is licensed under MIT.