Re: [PATCH] Disable year 2038 support on 32-bit hosts by default

[Luis Machado via Gdb-patches <gdb-patches@sourceware.org>]

On 8/8/22 18:55, Paul Eggert wrote:
> On 8/1/22 23:42, Luis Machado wrote:
>>
>> Maybe the best course of action is to get autoconf patched to support year2038 checks and then use that
>> in binutils-gdb.
> 
> Sorry, I'm a bit lost here.
> 
> GDB can already do what Gnulib's largefile module does; that's just some .m4 code. It sounds like you don't want GDB to do that, and instead want Autoconf to do something - presumably, modify Autoconf's AC_SYS_LARGEFILE to do the same thing that Gnulib's AC_SYS_LARGEFILE does). Although Autoconf could do that, I don't see why that would be be any better for GDB than GDB's using the equivalent of Gnulib's largefile module in GDB's ACX_LARGEFILE macro.
> 
> What am I missing?

The missing part here is that although GDB can indeed use Gnulib's default "enable 64-bit time_t on 32-bit hosts" check, BFD doesn't use Gnulib and so won't know anything about 64-bit time_t. BFD uses autoconf's AC_SYS_LARGEFILE, which seems like a copy of Gnulib's AC_SYS_LARGEFILE, sort of.

Given there is some shared code between GDB and BFD using struct stat, for example, this leads to memory corruption due to the discrepancies in struct size.