* i386bsd-nat.c: Include "gdb_assert.h".

[HAVE_PT_GETDBREGS] (DBREG_DRX): Define if not
already defined.
[HAVE_PT_GETDBREGS] (i386bsd_dr_set, i386bsd_dr_set_control,
i386bsd_dr_set_addr, i386bsd_dr_reset_addr,
i386bsd_dr_get_status): New functions.
* config/i386/nm-fbsd.h [HAVE_PT_GETDBREGS]
(I386_USE_GENERIC_WATCHPOINTS): Define.
Include "i386/nm-i386.h".
(I386_DR_LOW_SET_CONTROL, I386_DR_LOW_SET_ADDR,
I386_DR_LOW_RESET_ADDR, I386_DR_LOW_GET_STATUS): New macros.
(i386bsd_dr_set_control, i386bsd_dr_set_addr,
i386bsd_dr_reset_addr, i386bsd_dr_get_status): New prototypes.
* acconfig.h (HAVE_PT_GETDBREGS): New configure macro.
* configure.in: Cleanup a few comments.  Check for PT_GETDBREGS
ptrace request.
* config.in, configure: Regenerate.

1 files changed, 75 insertions, 0 deletions

diff --git a/gdb/i386bsd-nat.c b/gdb/i386bsd-nat.c
index e991ba0..3fdda7b 100644
--- a/gdb/i386bsd-nat.c
+++ b/gdb/i386bsd-nat.c
@@ -22,6 +22,7 @@
 #include "inferior.h"
 #include "regcache.h"
 
+#include "gdb_assert.h"
 #include <sys/types.h>
 #include <sys/ptrace.h>
 #include <machine/reg.h>
@@ -215,6 +216,80 @@ store_inferior_registers (int regno)
 }
 
 
+/* Support for debug registers.  */
+
+#ifdef HAVE_PT_GETDBREGS
+
+/* Not all versions of FreeBSD/i386 that support the debug registers
+   have this macro.  */
+#ifndef DBREG_DRX
+#define DBREG_DRX(d, x) ((&d->dr0)[x])
+#endif
+
+static void
+i386bsd_dr_set (int regnum, unsigned int value)
+{
+  struct dbreg dbregs;
+
+  if (ptrace (PT_GETDBREGS, inferior_pid, (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
+    perror_with_name ("Couldn't get debug registers");
+
+  /* For some mysterious reason, some of the reserved bits in the
+     debug control register get set.  Mask these off, otherwise the
+     ptrace call below will fail.  */
+  dbregs.dr7 &= ~(0x0000fc00);
+
+  DBREG_DRX ((&dbregs), regnum) = value;
+
+  if (ptrace (PT_SETDBREGS, inferior_pid, (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
+    perror_with_name ("Couldn't write debug registers");
+}
+
+void
+i386bsd_dr_set_control (unsigned long control)
+{
+  i386bsd_dr_set (7, control);
+}
+
+void
+i386bsd_dr_set_addr (int regnum, CORE_ADDR addr)
+{
+  gdb_assert (regnum >= 0 && regnum <= 4);
+
+  i386bsd_dr_set (regnum, addr);
+}
+
+void
+i386bsd_dr_reset_addr (int regnum)
+{
+  gdb_assert (regnum >= 0 && regnum <= 4);
+
+  i386bsd_dr_set (regnum, 0);
+}
+
+unsigned long
+i386bsd_dr_get_status (void)
+{
+  struct dbreg dbregs;
+
+  /* FIXME: kettenis/2001-03-31: Calling perror_with_name if the
+     ptrace call fails breaks debugging remote targets.  The correct
+     way to fix this is to add the hardware breakpoint and watchpoint
+     stuff to the target vectore.  For now, just return zero if the
+     ptrace call fails.  */
+  if (ptrace (PT_GETDBREGS, inferior_pid, (PTRACE_ARG3_TYPE) &dbregs, 0) == -1)
+#if 0
+    perror_with_name ("Couldn't read debug registers");
+#else
+    return 0;
+#endif
+
+  return dbregs.dr6;
+}
+
+#endif /* PT_GETDBREGS */
+
+
 /* Support for the user struct.  */
 
 /* Return the address register REGNO.  BLOCKEND is the value of