Report compiler crash

[mlutze]

No description provided.

[magnus-madsen]

Here is a program that crashes Flix:

pub enum E with Eq, Order

it would be nice if VSCode could report that somehow.

[mR4smussen]

I’m not completely sure how to crash the compiler. By using pub enum E with Eq, Order I can get the compiler to try to print an empty {} diagnostic, which gives an error and simply clears the console. I can check for this simply by checking that the diagnostic wasn’t an empty object !_.isEqual(result, {}) but then (since the console isn’t cleared) I get the error below. When I remove the line resulting in this error the compiler seems to work as before (didn’t crash)?

>> Undefined name 'pub'.

4 | /pub enum E with Eq, Order
     ^^^
     name not found


Explanation:
Tip: Possible typo or non-existent definition?
#
# An unexpected error has been detected by the Flix compiler:
#
#   head of empty list
#
# This is a bug in the Flix compiler. Please report it here:
#
# https://github.com/flix/flix/issues
#
# -- Flix Compiler --
#
# Flix Version : 0.34.0
#   incremental: All
#
# -- Java Virtual Machine --
#
# JVM Version  : 17.0.5 (2022-10-18)
# JVM Vendor   : Eclipse Adoptium
# JAVA_HOME    : C:\Program Files\Eclipse Adoptium\jdk-17.0.5.8-hotspot
# System       : Windows 10 (10.0)
#
# -- Stack Trace --
java.util.NoSuchElementException: head of empty list
	at scala.collection.immutable.Nil$.head(List.scala:629)
	at scala.collection.immutable.Nil$.head(List.scala:628)
	at ca.uwaterloo.flix.language.phase.unification.Unification$.unifyTypeM(Unification.scala:322)
        ... [more]

[magnus-madsen]

@mlutze What do we actually want here? A pop-up or what?

[mlutze]

Yes, I think a pop-up would be appropriate, as long as the stacktrace is printed somewhere.

[magnus-madsen]

Does the language server return some error code?

[mR4smussen]

Something like this? The stack trace is included in the crash report

[mlutze]

Can the popup link to the crash report?

[mR4smussen]

Does the language server return some error code?

I only think it returns it as a failure (https://github.com/flix/flix/blob/master/main/src/ca/uwaterloo/flix/api/lsp/LanguageServer.scala#L356-L357)

Can the popup link to the crash report?

I'll look into this.
Edit: I don't think this would be possible without returning more information from the compiler. The crash report is handled by the compiler, and I don't have access to anything regarding the name on the vscode side.

[magnus-madsen]

@sockmaster27 There is a lot of text above, but it is not too important. Here is the main task.

We currently return a JSON object with status = success or failure from the Flix compiler.

I would like to change this so that status can be one of three:

• OK - as before, ALL OK
• INVALID_REQUEST - corresponds to failure except in the crash case.
• COMPILER_ERROR - corresponds to a compiler crash.

When a COMPILER_ERROR is encountered we should show a message like in #256

We probably want to introduce an enum in both the compiler and VSCode.

Does it make sense? This is not too high priority.

[sockmaster27]

Here is a program that crashes Flix:

pub enum E with Eq, Order

it would be nice if VSCode could report that somehow.

This doesn't appear to work anymore. Is there something else I can use to test it?

[magnus-madsen]

@mlutze @JonathanStarup Do we have any know program that crashes the compiler?

@sockmaster27
Maybe check out

https://github.com/flix/flix/issues?q=is%3Aissue+is%3Aopen+label%3Abug

[sockmaster27]

Found one 👍