[RFA] Fix compiling amd64-linux-nat.c on old glibcs [was Re: new siginfo support doesn't build on glibc 2.2.2]

[Doug Evans <dje@google.com>]

On Mon, Feb 9, 2009 at 3:55 PM, Pedro Alves <pedro@codesourcery.com> wrote:
> On Monday 09 February 2009 21:07:41, Doug Evans wrote:
>> fyi, glibc 2.2.2 doesn't have si_timerid, si_overrun.  compilation of
>> amd64-linux-nat.c fails.
>
> Bummer.  According to sigaction(2), those exist only since kernel
> 2.6.  Those are defines, we could #ifdef on them, assuming we're
> ok with a gdb built on that platform and then moved to some more
> recent glibc will not translate those fields.
>
> I don't know if the siginfo layout in that version is the same
> as defined by the gdbarch callback, or even if your glibc's siginfo_t
> declaration matches your kernel's siginfo_t object layout --- there's
> a history of breakage on these matters.
>
>> Dunno how old a glibc we intend to support for 7.0.
>
> Could you try ifdefing those fields, and see what comes out of
> $_siginfo; and taking a peek at your headers, to see if we're
> doing something reasonable?  We have a couple of siginfo related
> testcases that may help as small test apps.
>
> --
> Pedro Alves
>

How about this?

2009-03-16  Doug Evans  <dje@google.com>

        * amd64-linux-nat.c (si_timerid,si_overrun): Provide definition for
        glibc 2.3.2 and earlier.

Index: amd64-linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/amd64-linux-nat.c,v
retrieving revision 1.24
diff -u -p -u -p -r1.24 amd64-linux-nat.c
--- amd64-linux-nat.c   23 Feb 2009 00:03:48 -0000      1.24
+++ amd64-linux-nat.c   17 Mar 2009 00:00:40 -0000
@@ -501,6 +501,15 @@ typedef struct compat_siginfo
 #define cpt_si_band _sifields._sigpoll._band
 #define cpt_si_fd _sifields._sigpoll._fd

+/* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun.
+   In their place is si_timer1,si_timer2.  */
+#ifndef si_timerid
+#define si_timerid si_timer1
+#endif
+#ifndef si_overrun
+#define si_overrun si_timer2
+#endif
+
 static void
 compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from)
 {