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[patch] ppc-linux-nat.c: Fix gcc-4.7 aliasing warnings
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- To: gdb-patches at sourceware dot org
- Date: Thu, 9 Feb 2012 19:18:57 +0100
- Subject: [patch] ppc-linux-nat.c: Fix gcc-4.7 aliasing warnings
Hi,
ppc-linux-nat.c: In function ‘fetch_register’:
ppc-linux-nat.c:598:9: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
ppc-linux-nat.c: In function ‘store_register’:
ppc-linux-nat.c:1078:8: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
gcc-4.7.0-0.10.fc17.ppc64
Probably clear, I looked at making it using union instead of memcpy but that
would be too ugly.
No regressions on ppc64-fedorarawhide-linux-gnu only for gdb.base/*.exp.
I will check it in.
Thanks,
Jan
gdb/
2012-02-09 Jan Kratochvil <jan.kratochvil@redhat.com>
* ppc-linux-nat.c (fetch_register, store_register): Fix GCC aliasing
compilation warning.
--- a/gdb/ppc-linux-nat.c
+++ b/gdb/ppc-linux-nat.c
@@ -593,9 +593,10 @@ fetch_register (struct regcache *regcache, int tid, int regno)
bytes_transferred < register_size (gdbarch, regno);
bytes_transferred += sizeof (long))
{
+ long l;
+
errno = 0;
- *(long *) &buf[bytes_transferred]
- = ptrace (PTRACE_PEEKUSER, tid, (PTRACE_TYPE_ARG3) regaddr, 0);
+ l = ptrace (PTRACE_PEEKUSER, tid, (PTRACE_TYPE_ARG3) regaddr, 0);
regaddr += sizeof (long);
if (errno != 0)
{
@@ -604,6 +605,7 @@ fetch_register (struct regcache *regcache, int tid, int regno)
gdbarch_register_name (gdbarch, regno), regno);
perror_with_name (message);
}
+ memcpy (&buf[bytes_transferred], &l, sizeof (l));
}
/* Now supply the register. Keep in mind that the regcache's idea
@@ -1073,9 +1075,11 @@ store_register (const struct regcache *regcache, int tid, int regno)
for (i = 0; i < bytes_to_transfer; i += sizeof (long))
{
+ long l;
+
+ memcpy (&l, &buf[i], sizeof (l));
errno = 0;
- ptrace (PTRACE_POKEUSER, tid, (PTRACE_TYPE_ARG3) regaddr,
- *(long *) &buf[i]);
+ ptrace (PTRACE_POKEUSER, tid, (PTRACE_TYPE_ARG3) regaddr, l);
regaddr += sizeof (long);
if (errno == EIO