Fix building on x86 OpenBSD 4.3

[Pedro Alves <pedro@codesourcery.com>]

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Hi,

In my testing on several targets, I noticed that GDB isn't
building on x86 OpenBSD 4.3, due to the fact that struct
switchframe got its sf_ppl member removed, and GDB is trying
to access it.

I can't claim I know a think about this, but,

The patch that seems to have removed it, shows that is was always
0 just before removal:

 http://archive.netbsd.se/?ml=openbsd-tech&a=2007-09&m=5239543

And I can see it being set to != 0 in that files' history at:
 http://opengrok.creo.hu/openbsd/history/src/sys/arch/i386/i386/vm_machdep.c

So, I guess that the attached is the best to do, and I didn't
notice any breakage.  Of course, I don't even know what
triggers this code path.  :-)

Mark, perhaps you have a better fix in your local trees?

OK?

-- 
Pedro Alves

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2008-08-06  Pedro Alves  <pedro@codesourcery.com>

	* i386obsd-nat.c (i386obsd_supply_pcb): Remove handling of
	switchframe.sf_ppl != 0.

---
 gdb/i386obsd-nat.c |   21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

Index: src/gdb/i386obsd-nat.c
===================================================================
--- src.orig/gdb/i386obsd-nat.c	2008-01-01 22:53:11.000000000 +0000
+++ src/gdb/i386obsd-nat.c	2008-08-06 16:00:41.000000000 +0100
@@ -61,21 +61,12 @@ i386obsd_supply_pcb (struct regcache *re
      checking if the saved interrupt priority level in the stack frame
      looks reasonable..  */
   read_memory (pcb->pcb_esp, (char *) &sf, sizeof sf);
-  if ((unsigned int) sf.sf_ppl < 0x100 && (sf.sf_ppl & 0xf) == 0)
-    {
-      /* Yes, we have a frame that matches cpu_switch().  */
-      pcb->pcb_esp += sizeof (struct switchframe);
-      regcache_raw_supply (regcache, I386_EDI_REGNUM, &sf.sf_edi);
-      regcache_raw_supply (regcache, I386_ESI_REGNUM, &sf.sf_esi);
-      regcache_raw_supply (regcache, I386_EBX_REGNUM, &sf.sf_ebx);
-      regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf.sf_eip);
-    }
-  else
-    {
-      /* No, the pcb must have been last updated by savectx().  */
-      pcb->pcb_esp += 4;
-      regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf);
-    }
+
+  pcb->pcb_esp += sizeof (struct switchframe);
+  regcache_raw_supply (regcache, I386_EDI_REGNUM, &sf.sf_edi);
+  regcache_raw_supply (regcache, I386_ESI_REGNUM, &sf.sf_esi);
+  regcache_raw_supply (regcache, I386_EBX_REGNUM, &sf.sf_ebx);
+  regcache_raw_supply (regcache, I386_EIP_REGNUM, &sf.sf_eip);
 
   regcache_raw_supply (regcache, I386_EBP_REGNUM, &pcb->pcb_ebp);
   regcache_raw_supply (regcache, I386_ESP_REGNUM, &pcb->pcb_esp);