[pushed][gdb/build] Fix x86_64 x32 build

[Tom de Vries via Gdb-patches <gdb-patches@sourceware.org>]

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On 11/22/21 9:38 AM, Jan Palus wrote:
> On 22.11.2021 07:46, Tom de Vries wrote:
>> On 11/21/21 8:45 PM, Jan Palus wrote:
>>> gdb 11.1 fails during compilation on x32 ABI:
>>>
>>> ../.././gdbserver/../gdb/nat/amd64-linux-siginfo.c:280:42: error: 'struct compat_x32_siginfo_t::<unnamed union>::<unnamed>' has no member named 'si_addr_bnd'
>>> 280 | #define cpt_si_lower _sifields._sigfault.si_addr_bnd._lower
>>> | ^~~~~~~~~~~
>>> ../.././gdbserver/../gdb/nat/amd64-linux-siginfo.c:337:38: note: in expansion of macro 'cpt_si_lower'
>>> 337 | to->cpt_si_lower = from_ptrace.cpt_si_lower;
>>> | ^~~~~~~~~~~~
>>> ../.././gdbserver/../gdb/nat/amd64-linux-siginfo.c:281:42: error: 'struct compat_x32_siginfo_t::<unnamed union>::<unnamed>' has no member named 'si_addr_bnd'
>>> 281 | #define cpt_si_upper _sifields._sigfault.si_addr_bnd._upper
>>> | ^~~~~~~~~~~
>>> ../.././gdbserver/../gdb/nat/amd64-linux-siginfo.c:338:38: note: in expansion of macro 'cpt_si_upper'
>>> 338 | to->cpt_si_upper = from_ptrace.cpt_si_upper;
>>> | ^~~~~~~~~~~~
>>>
>>> I believe it is caused by https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;h=d3d7d1b
>>
>> Hi,
>>
>> I've attached a conservative fix, can you check whether that fixes the
>> build breaker?
> 
> Thanks. That's essentially the same fix as the temporary workaround I
> came up with:
> 
> http://git.pld-linux.org/?p=packages/gdb.git;a=commitdiff;h=9f79cb7
> 
> and can confirm that it fixes the failure and build is successful on x32.

Committed as attached below.

Thanks,
- Tom


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[gdb/build] Fix x86_64 x32 build

A build error on x86_64 with x32 abi was reported here (
https://sourceware.org/pipermail/gdb/2021-November/049787.html ):
...
gdb/nat/amd64-linux-siginfo.c:280:42: error: \
  'struct compat_x32_siginfo_t::<unnamed union>::<unnamed>' has no member \
  named 'si_addr_bnd'
280 | #define cpt_si_lower _sifields._sigfault.si_addr_bnd._lower
| ^~~~~~~~~~~
gdb/nat/amd64-linux-siginfo.c:337:38: note: in expansion of macro 'cpt_si_lower'
337 | to->cpt_si_lower = from_ptrace.cpt_si_lower;
| ^~~~~~~~~~~~
...

The problem is that code added in commit d3d7d1ba3bb "[gdb/tdep] Handle
si_addr_bnd in compat_siginfo_from_siginfo" doesn't compile on an x86_64 x32
setup, because compat_x32_siginfo_t doesn't have the si_addr_bnd fields.

Fix this conservatively by disabling the code for x32.

Tested on x86_64-linux.

---
 gdb/nat/amd64-linux-siginfo.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gdb/nat/amd64-linux-siginfo.c b/gdb/nat/amd64-linux-siginfo.c
index 342840e5085..fc52b5b6056 100644
--- a/gdb/nat/amd64-linux-siginfo.c
+++ b/gdb/nat/amd64-linux-siginfo.c
@@ -330,6 +330,9 @@ compat_siginfo_from_siginfo (compat_siginfo_t *to, const siginfo_t *from)
       to->cpt_si_pid = from_ptrace.cpt_si_pid;
       to->cpt_si_uid = from_ptrace.cpt_si_uid;
     }
+#ifndef __ILP32__
+  /* The struct compat_x32_siginfo_t doesn't contain
+     cpt_si_lower/cpt_si_upper.  */
   else if (to->si_code == SEGV_BNDERR
 	   && to->si_signo == SIGSEGV)
     {
@@ -337,6 +340,7 @@ compat_siginfo_from_siginfo (compat_siginfo_t *to, const siginfo_t *from)
       to->cpt_si_lower = from_ptrace.cpt_si_lower;
       to->cpt_si_upper = from_ptrace.cpt_si_upper;
     }
+#endif
   else if (to->si_code < 0)
     {
       to->cpt_si_pid = from_ptrace.cpt_si_pid;