Berry exception location via FFI

[Conaclos]

Hi!

I am currently using FFI to execute functions defined in a berry script.
Unfortunately, when an error happens, there is no info about the location where the error occurred.

I noticed that loading/executing a script via the CLI emits a traceback.
For example:

❯ berry script.be
type_error: unsupported operand type(s) for +: 'int' and 'bool'
stack traceback:
	script:2: in function `main`

Is it possible to get traceback or location info when executing a function via FFI?

[s-hadinger]

It’s hard to understand what you are doing, but the error you are reporting is line 2 and related to Berry code, not native code

[Conaclos]

I would like to use Berry as a scripting environment. I have no control over user scripts. If an error occurs in a script, I would like to report the error to the user and indicate where the error occurred (line number). The example I gave is a script I wrote (1 + true) with an intentional runtime error. I want to extract the location info from the error that Berry emits if it is possible. My question is: is it possible to extract the location of a runtime error?

[s-hadinger]

Ah ok. This should be possible with some extra code. When running the user script with be_pcall() (p stands for protected), you will receive a specific error code indicating that an exception was raised and you can extract the type string and message from the exception.

To extract line number, I don't think it's directly addressable, but you can take example on tracestack() to extract line number information from the stack trace.

[Conaclos]

Ah ok. This should be possible with some extra code. When running the user script with be_pcall() (p stands for protected), you will receive a specific error code indicating that an exception was raised and you can extract the type string and message from the exception.

Yeah, I already did that, but the line number is missing.
Here the stack I got (custom format) with the previous toy example:

[
    Function,
    "type_error",
    "unsupported operand type(s) for +: \'int\' and \'bool\'",
]

To extract line number, I don't think it's directly addressable, but you can take example on tracestack() to extract line number information from the stack trace.
Thanks for the pointer. I will take a look.