2004-03-23 Andrew Cagney <cagney@redhat.com>

	* tramp-frame.h, tramp-frame.h: New files.
	* Makefile.in (SFILES, tramp_frame_h, COMMON_OBS, tramp-frame.o):
	Update rules to include "tramp-frame.h" and "tramp-frame.c".

1 files changed, 162 insertions, 0 deletions

diff --git a/gdb/tramp-frame.c b/gdb/tramp-frame.c
new file mode 100644
index 0000000..7a8057e
--- /dev/null
+++ b/gdb/tramp-frame.c
@@ -0,0 +1,162 @@
+/* Signal trampoline unwinder, for GDB the GNU Debugger.
+
+   Copyright 2004 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "defs.h"
+#include "tramp-frame.h"
+#include "frame-unwind.h"
+#include "gdbcore.h"
+#include "symtab.h"
+#include "objfiles.h"
+#include "target.h"
+#include "trad-frame.h"
+#include "frame-base.h"
+
+struct frame_data
+{
+  const struct tramp_frame *tramp_frame;
+};
+
+struct tramp_frame_cache
+{
+  CORE_ADDR func;
+  const struct tramp_frame *tramp_frame;
+  struct trad_frame_cache *trad_cache;
+};
+
+static struct trad_frame_cache *
+tramp_frame_cache (struct frame_info *next_frame,
+		   void **this_cache)
+{
+  CORE_ADDR pc = frame_pc_unwind (next_frame);
+  struct tramp_frame_cache *tramp_cache = (*this_cache);
+  if (tramp_cache->trad_cache == NULL)
+    {
+      tramp_cache->trad_cache = trad_frame_cache_zalloc (next_frame);
+      tramp_cache->tramp_frame->init (tramp_cache->tramp_frame,
+				      next_frame,
+				      tramp_cache->trad_cache,
+				      tramp_cache->func);
+    }
+  return tramp_cache->trad_cache;
+}
+
+static void
+tramp_frame_this_id (struct frame_info *next_frame,
+		     void **this_cache,
+		     struct frame_id *this_id)
+{
+  struct trad_frame_cache *trad_cache
+    = tramp_frame_cache (next_frame, this_cache);
+  trad_frame_get_id (trad_cache, this_id);
+}
+
+static void
+tramp_frame_prev_register (struct frame_info *next_frame,
+			   void **this_cache,
+			   int prev_regnum,
+			   int *optimizedp,
+			   enum lval_type * lvalp,
+			   CORE_ADDR *addrp,
+			   int *realnump, void *valuep)
+{
+  struct trad_frame_cache *trad_cache
+    = tramp_frame_cache (next_frame, this_cache);
+  trad_frame_get_register (trad_cache, next_frame, prev_regnum, optimizedp,
+			   lvalp, addrp, realnump, valuep);
+}
+
+static CORE_ADDR
+tramp_frame_start (CORE_ADDR pc, const struct tramp_frame *tramp)
+{
+  int ti;
+  /* Search through the trampoline for one that matches the
+     instruction sequence around PC.  */
+  for (ti = 0; tramp->insn[ti] != 0; ti++)
+    {
+      CORE_ADDR func = pc - tramp->insn_size * ti;
+      int i;
+      for (i = 0; 1; i++)
+	{
+	  bfd_byte buf[sizeof (LONGEST)];
+	  CORE_ADDR insn;
+	  if (tramp->insn[i] == 0)
+	    return func;
+	  if (target_read_memory (func + i * tramp->insn_size, buf,
+				  tramp->insn_size) != 0)
+	    break;
+	  insn = extract_unsigned_integer (buf, tramp->insn_size);
+	  if (tramp->insn[i] != insn)
+	    break;
+	}
+    }
+  /* Trampoline doesn't match.  */
+  return 0;
+}
+
+static int
+tramp_frame_sniffer (const struct frame_unwind *self,
+		     struct frame_info *next_frame,
+		     void **this_cache)
+{
+  const struct tramp_frame *tramp = self->unwind_data->tramp_frame;
+  CORE_ADDR pc = frame_pc_unwind (next_frame);
+  CORE_ADDR func;
+  char *name;
+  struct tramp_frame_cache *tramp_cache;
+
+  /* If the function has a valid symbol name, it isn't a
+     trampoline.  */
+  find_pc_partial_function (pc, &name, NULL, NULL);
+  if (name != NULL)
+    return 0;
+  /* If the function lives in a valid section (even without a starting
+     point) it isn't a trampoline.  */
+  if (find_pc_section (pc) != NULL)
+    return 0;
+  /* Finally, check that the trampoline matches at PC.  */
+  func = tramp_frame_start (pc, tramp);
+  if (func == 0)
+    return 0;
+  tramp_cache = FRAME_OBSTACK_ZALLOC (struct tramp_frame_cache);
+  tramp_cache->func = func;
+  tramp_cache->tramp_frame = tramp;
+  (*this_cache) = tramp_cache;
+  return 1;
+}
+
+void
+tramp_frame_append (struct gdbarch *gdbarch,
+		    const struct tramp_frame *tramp_frame)
+{
+  struct frame_data *data;
+  struct frame_unwind *unwinder;
+
+  data = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_data);
+  unwinder = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind);
+
+  data->tramp_frame = tramp_frame;
+  unwinder->type = SIGTRAMP_FRAME;
+  unwinder->unwind_data = data;
+  unwinder->sniffer = tramp_frame_sniffer;
+  unwinder->this_id = tramp_frame_this_id;
+  unwinder->prev_register = tramp_frame_prev_register;
+  frame_unwind_register_unwinder (gdbarch, unwinder);
+}