* sparc-tdep.h (struct gdbarch_tdep): Add step_trap member.

(sparc_address_from_register): New prototype.
(sparcnbsd_step_trap): New prototype.
* sparc-tdep.c (sparc_address_from_register): Make globally
visible.
(sparc_analyze_control_transfer): Change prototype to accept
`struct gdbarch *' as first argument.  Allow for optional hnadling
for trap instructions.
(sparc_step_trap): New function.
(sparc_software_single_step): Adjust call to
sparc_analyze_control_trabsfer.
(sparc32_gdbarch_init): Initialize TDEP->step_trap.
* sparcnbsd-tdep.c (sparcnbsd_step_trap): New function.
(sparc32nbsd_init_abi): Set TDEP->step_trap.
* sparc64obsd-tdep.c (sparc64obsd_init_abi): Set TDEP->step_trap.
* sparc64nbsd-tdep.c (sparc64nbsd_init_abi): Set TDEP->step_trap.

1 files changed, 33 insertions, 1 deletions

diff --git a/gdb/sparcnbsd-tdep.c b/gdb/sparcnbsd-tdep.c
index 6862bdc..73dee14 100644
--- a/gdb/sparcnbsd-tdep.c
+++ b/gdb/sparcnbsd-tdep.c
@@ -1,6 +1,6 @@
 /* Target-dependent code for NetBSD/sparc.
 
-   Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004, 2006 Free Software Foundation, Inc.
    Contributed by Wasabi Systems, Inc.
 
    This file is part of GDB.
@@ -38,6 +38,11 @@
 #include "sparc-tdep.h"
 #include "nbsd-tdep.h"
 
+/* Macros to extract fields from SPARC instructions.  */
+#define X_RS1(i) (((i) >> 14) & 0x1f)
+#define X_RS2(i) ((i) & 0x1f)
+#define X_I(i) (((i) >> 13) & 1)
+
 const struct sparc_gregset sparc32nbsd_gregset =
 {
   0 * 4,			/* %psr */
@@ -256,6 +261,30 @@ sparc32nbsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
   return NULL;
 }
 
+/* Return the address of a system call's alternative return
+   address.  */
+
+CORE_ADDR
+sparcnbsd_step_trap (unsigned long insn)
+{
+  if ((X_I (insn) == 0 && X_RS1 (insn) == 0 && X_RS2 (insn) == 0)
+      || (X_I (insn) == 1 && X_RS1 (insn) == 0 && (insn & 0x7f) == 0))
+    {
+      /* "New" system call.  */
+      ULONGEST number;
+
+      regcache_cooked_read_unsigned (current_regcache,
+				     SPARC_G1_REGNUM, &number);
+
+      if (number & 0x400)
+	return sparc_address_from_register (SPARC_G2_REGNUM);
+      if (number & 0x800)
+	return sparc_address_from_register (SPARC_G7_REGNUM);
+    }
+
+  return 0;
+}
+
 
 static void
 sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -272,6 +301,9 @@ sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   tdep->fpregset = regset_alloc (gdbarch, sparc32nbsd_supply_fpregset, NULL);
   tdep->sizeof_fpregset = 33 * 4;
 
+  /* Make sure we can single-step "new" syscalls.  */
+  tdep->step_trap = sparcnbsd_step_trap;
+
   frame_unwind_append_sniffer (gdbarch, sparc32nbsd_sigtramp_frame_sniffer);
 }