Re: gdb build problem (gdb/unittests/scoped_mmap-selftests.c)

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2018-08-08 13:56, Tom Tromey wrote:
>>>>>> "Simon" == Simon Marchi <simon.marchi@polymtl.ca> writes:
> 
> Simon> I think that enabling _FORTIFY_SOURCE can only do some good.
> 
> What do you think of the appended?
> The check for __OPTIMIZE__ has to be done since otherwise a glibc 
> header
> will complain.
> 
> Building with this patch applied (after autoheader etc) let me 
> reproduce
> Steve's original problem.
> 
> Tom
> 
> diff --git a/gdb/configure.ac b/gdb/configure.ac
> index 13bc5f9a8f2..76a1ba0364f 100644
> --- a/gdb/configure.ac
> +++ b/gdb/configure.ac
> @@ -2279,6 +2279,10 @@ dnl  At the moment, we just assume it's UTF-8.
>  AC_DEFINE(GDB_DEFAULT_HOST_CHARSET, "UTF-8",
>            [Define to be a string naming the default host character 
> set.])
> 
> +AH_BOTTOM([#if defined __OPTIMIZE__ && __OPTIMIZE__ > 0
> +#define _FORTIFY_SOURCE 2
> +#endif])
> +
>  if $development; then
>    AC_DEFINE(GDB_SELF_TEST, 1,
>              [Define if self-testing features should be enabled])

Oh right, _FORTIFY_SOURCE requires building with optimization.  That 
code will end up at the bottom of config.h, is that it?  If so, it LGTM.

Simon