Hi Dmitry,
> I've tried to rebuild the latest GNU grep with the latest gnulib
> and got a few build issues:
> ...
> The following gnulib patch makes the compiler happy again:
>
> diff --git a/lib/sigsegv.c b/lib/sigsegv.c
> index 312f132b8..b0b406685 100644
> --- a/lib/sigsegv.c
> +++ b/lib/sigsegv.c
> @@ -1056,7 +1056,7 @@ sigsegv_handler (SIGSEGV_FAULT_HANDLER_ARGLIST)
> /* Handler declined responsibility for real. */
>
> /* Remove ourselves and dump core. */
> - SIGSEGV_FOR_ALL_SIGNALS (sig, signal (sig, SIG_DFL);)
> + SIGSEGV_FOR_ALL_SIGNALS (signo, signal (signo, SIG_DFL);)
> }
>
> # if HAVE_STACK_OVERFLOW_RECOVERY
Thanks for the report. This patch is good, but needs to be applied also to
the other sigsegv_handler, and also to libsigsegv (to be kept in sync when
possible). I'm doing that now.
>
> -volatile int *
> +static volatile int *
> recurse_1 (int n, volatile int *p)
> {
> if (n < INT_MAX)
> @@ -80,7 +80,7 @@ recurse_1 (int n, volatile int *p)
> return p;
> }
>
> -int
> +static int
> recurse (volatile int n)
> {
> return *recurse_1 (n, &n);
This part should better not be applied. It may enable compiler optimizations
(now or in the future) that, in the end, turn an endless recursion into an
endless loop.
> @@ -183,6 +183,9 @@ main ()
> *(volatile int *) (page + 0x678) = 42;
> break;
> case 3:
> +#if 6 < __GNUC__
> +# pragma GCC diagnostic ignored "-Wnull-dereference"
> +#endif
> *(volatile int *) 0 = 42;
> break;
> case 4:
We shouldn't spend time eliminating warnings from test code.
The goal is to have a good coverage of the lib/* code with unit tests.
That means, we need to
- make it easy to write unit tests,
- not make it time-consuming to maintain them.
Eliminating warnings from lib/* code is useful, to avoid bugs in the
programs. But eliminating warnings from tests/* code goes against the
goal of increasing test coverage.
I think the right fix would be that gnulib-tool's --import/--update
option, when creating a tests directory, adds a $(CFLAG_ALLOW_WARNING)
to tests/Makefile.am, where CFLAG_ALLOW_WARNING is defined as
-Wno-error when the compiler is GCC or clang,
empty otherwise
Will that work in GNU grep?
Bruno
