Re: gdb -batch always exits with status 0

Hi,

On 5 July 2018 at 17:47, Gary Benson <[email protected]> wrote:
> Hi all,
>
> I've been working on fixing PR gdb/13000, which is that GDB in batch
> mode always exits with status 0 despite the manual saying it should
> exit with nonzero status on error.  The latter is what I'd intuitively
> expect, so I'm looking at fixing GDB to match the docs rather than
> fixing the docs to match GDB.
>
> A narrow fix to make GDB match the docs is actually fairly simple,
> but I'm bothered that not only does gdb -batch always exit with
> status 0, it actually continues over any number of errors before
> doing so.  So you can do something like:
>
>   bash$ echo nonsense > cmds
>   bash$ echo garbage > .gdbinit
>   bash$ gdb -batch -iex invalid-command -ex also-invalid \
>           -cd /no/such/directory -p 1 -batch -ix /does/not/exist \
>           -x cmds
>   Undefined command: "invalid-command".  Try "help".
>   warning: /does/not/exist: No such file or directory
>   /no/such/directory: No such file or directory.
>   ptrace: Operation not permitted.
>   .gdbinit:1: Error in sourced command file:
>   Undefined command: "garbage".  Try "help".
>   Undefined command: "also-invalid".  Try "help".
>   cmds:1: Error in sourced command file:
>   Undefined command: "nonsense".  Try "help".
>   bash$ echo $?
>   0
>
> Would anybody object to my changing GDB's behaviour to terminate
> on the first error in batch mode?

On the one hand, this totally makes sense. But on the other, can we
prevent exit if we e.g. expect a possible error and do the necessary
steps to fix it? An example use case: before starti command appeared,
it could be simulated by the following:

b *0
r
d 1

The above (unconditional!) sequence of commands would error on `r`,
but the side effect of the whole sequence would be the same as the
modern starti command. Your change would invalidate similar use cases
in batch mode.

>
> (I'd also like to remove the 'Try "help".' suffix when in batch mode,
> though I'd likely do that in a separate patch.)
>
> Cheers,
> Gary
>
> --
> https://gbenson.net/