[PATCH] Use gdbarch_long_bit to determine layout of FreeBSD siginfo_t.

[John Baldwin]

FreeBSD architectures are either ILP32 or LP64 resulting in two
different layouts for siginfo_t.  Previously, the 'bits_per_word'
member of bfd_arch_info was used to determine the layout to use for a
given FreeBSD architecture.  However, mipsn32 architectures inherit
from a 64-bit mips architecture where bits_per_word is 64.  As a
result, $_siginfo was not properly extracted from FreeBSD/mipsn32 core
dumps.  Fix this by using gdbarch_long_bit instead of 'bits_per_word'
to determine if a FreeBSD architecture is ILP32 or LP64.

gdb/ChangeLog:

	* fbsd-nat.c (fbsd_siginfo_size): Use gdbarch_long_bit.
	(fbsd_convert_siginfo): Likewise.
	* fbsd-tdep.c (fbsd_core_xfer_siginfo): Likewise.
---
 gdb/ChangeLog   | 6 ++++++
 gdb/fbsd-nat.c  | 4 ++--
 gdb/fbsd-tdep.c | 4 ++--
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 18224e0305..f72c47302e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-10-06  John Baldwin  <jhb@FreeBSD.org>
+
+	* fbsd-nat.c (fbsd_siginfo_size): Use gdbarch_long_bit.
+	(fbsd_convert_siginfo): Likewise.
+	* fbsd-tdep.c (fbsd_core_xfer_siginfo): Likewise.
+
 2017-10-06  Yao Qi  <yao.qi@linaro.org>
 
 	* Makefile.in (ALL_64_TARGET_OBS): Replace aarch64-insn.o with
diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c
index 5ad0dda5b4..265175a769 100644
--- a/gdb/fbsd-nat.c
+++ b/gdb/fbsd-nat.c
@@ -279,7 +279,7 @@ fbsd_siginfo_size ()
   struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
 
   /* Is the inferior 32-bit?  If so, use the 32-bit siginfo size.  */
-  if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
+  if (gdbarch_long_bit (gdbarch) == 32)
     return sizeof (struct siginfo32);
 #endif
   return sizeof (siginfo_t);
@@ -296,7 +296,7 @@ fbsd_convert_siginfo (siginfo_t *si)
   struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
 
   /* Is the inferior 32-bit?  If not, nothing to do.  */
-  if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word != 32)
+  if (gdbarch_long_bit (gdbarch) != 32)
     return;
 
   struct siginfo32 si32;
diff --git a/gdb/fbsd-tdep.c b/gdb/fbsd-tdep.c
index fa4cd912ef..fa70f7c20b 100644
--- a/gdb/fbsd-tdep.c
+++ b/gdb/fbsd-tdep.c
@@ -143,7 +143,7 @@ fbsd_core_xfer_siginfo (struct gdbarch *gdbarch, gdb_byte *readbuf,
 {
   size_t siginfo_size;
 
-  if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
+  if (gdbarch_long_bit (gdbarch) == 32)
     siginfo_size = SIZE32_SIGINFO_T;
   else
     siginfo_size = SIZE64_SIGINFO_T;
@@ -168,7 +168,7 @@ fbsd_core_xfer_siginfo (struct gdbarch *gdbarch, gdb_byte *readbuf,
     len = siginfo_size - offset;
 
   ULONGEST siginfo_offset;
-  if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
+  if (gdbarch_long_bit (gdbarch) == 32)
     siginfo_offset = LWPINFO_OFFSET + LWPINFO32_PL_SIGINFO;
   else
     siginfo_offset = LWPINFO_OFFSET + LWPINFO64_PL_SIGINFO;
-- 
2.13.3