Re: [PATCH] driver: ignore SIGINT while waiting on subprocesses to finish

[Patrick Palka <patrick at parcs dot ath dot cx>]

On Sat, 15 Nov 2014, Patrick Palka wrote:

> Currently the top-level driver handles SIGINT by immediately killing
> itself even when the driver has subprocesses (e.g. cc1, as) running.  I
> don't think this is a good idea because
>
>  1. if the top-level driver is waiting on a hanging subprocess,
>  pressing ^C will kill the driver but it may not necessarily kill the
>  subprocess; an unresponsive, perhaps busy-looping subprocess may be
>  running in the background yet the compiler will seem to have to
>  terminated successfully.
>
>  2. when debugging gcc with "gcc -wrapper gdb,--args" we are unable to
>  use ^C from within the GDB subprocess because pressing ^C immediately
>  kills the driver and we lose our terminal.  This makes debugging more
>  inconvenient.
>
> This patch fixes these two issues by having the driver ignore SIGINT
> while a subprocess is running.  The driver instead will have to wait for
> the subprocess to exit before it terminates, like usual.
>
> I tested this change by running "gcc -wrapper gdb", "gcc -wrapper
> valgrind" and plain old "gcc" in various ways (-pipe, -flto, -c, etc)
> and pressing ^C during compilation.  I noticed no differences in
> behavior or promptness other than finally being able to use ^C inside
> GDB.
>
> Does this change look OK for trunk after a successful bootstrap +
> regtest on x86_64-unknown-linux-gnu?

I forgot a ChangeLog entry:

	* gcc.c (ignore_sigint_p): New static variable.
	(execute): Use it.
	(fatal_signal): Ignore SIGINT if ignore_sigint_p is true.