2003-11-14 Jeff Johnston <jjohnstn@redhat.com>

        * libunwind-frame.c: New file.
        * libunwind-frame.h: New file.
        * acconfig.h (HAVE_LIBUNWIND): #undef reference added.
        * configure.in: Add --with-libunwind option support.  Define
        HAVE_LIBUNWIND if libunwind support selected / defaulted.
        Also check for libunwind.h and libunwind-ia64.h headers.
        * configure: Regenerated.
        * Makefile.in: Add support for libunwind-frame.o.
        * config.in: Regenerated.

1 files changed, 388 insertions, 0 deletions

diff --git a/gdb/libunwind-frame.c b/gdb/libunwind-frame.c
new file mode 100644
index 0000000..d23ec56
--- /dev/null
+++ b/gdb/libunwind-frame.c
@@ -0,0 +1,388 @@
+/* Frame unwinder for frames using the libunwind library.
+
+   Copyright 2003 Free Software Foundation, Inc.
+
+   Written by Jeff Johnston, contributed by Red Hat 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 "inferior.h"
+#include "frame.h"
+#include "frame-base.h"
+#include "frame-unwind.h"
+#include "gdbcore.h"
+#include "gdbtypes.h"
+#include "symtab.h"
+#include "objfiles.h"
+#include "regcache.h"
+
+#include <dlfcn.h>
+
+#include "gdb_assert.h"
+#include "gdb_string.h"
+
+#include "libunwind-frame.h"
+
+#include "complaints.h"
+
+static int libunwind_initialized;
+static struct gdbarch_data *libunwind_descr_handle;
+
+#ifndef LIBUNWIND_SO
+#define LIBUNWIND_SO "libunwind.so"
+#endif
+
+/* Required function pointers from libunwind.  */
+static int (*unw_get_reg_p) (unw_cursor_t *, unw_regnum_t, unw_word_t *);
+static int (*unw_get_fpreg_p) (unw_cursor_t *, unw_regnum_t, unw_fpreg_t *);
+static int (*unw_get_saveloc_p) (unw_cursor_t *, unw_regnum_t, unw_save_loc_t *);
+static int (*unw_step_p) (unw_cursor_t *);
+static int (*unw_init_remote_p) (unw_cursor_t *, unw_addr_space_t, void *);
+static unw_addr_space_t (*unw_create_addr_space_p) (unw_accessors_t *, int);
+static int (*unw_search_unwind_table_p) (unw_addr_space_t, unw_word_t, unw_dyn_info_t *,
+					 unw_proc_info_t *, int, void *);
+static unw_word_t (*unw_find_dyn_list_p) (unw_addr_space_t, void *, size_t,
+					  unw_word_t, unw_word_t, void *);
+
+
+struct libunwind_frame_cache
+{
+  CORE_ADDR base;
+  CORE_ADDR func_addr;
+  unw_cursor_t cursor;
+};
+
+/* We need to qualify the function names with a platform-specific prefix to match 
+   the names used by the libunwind library.  The UNW_OBJ macro is provided by the
+   libunwind.h header file.  */
+#define STRINGIFY2(name)	#name
+#define STRINGIFY(name)		STRINGIFY2(name)
+
+static char *get_reg_name = STRINGIFY(UNW_OBJ(get_reg));
+static char *get_fpreg_name = STRINGIFY(UNW_OBJ(get_fpreg));
+static char *get_saveloc_name = STRINGIFY(UNW_OBJ(get_save_loc));
+static char *step_name = STRINGIFY(UNW_OBJ(step));
+static char *init_remote_name = STRINGIFY(UNW_OBJ(init_remote));
+static char *create_addr_space_name = STRINGIFY(UNW_OBJ(create_addr_space));
+static char *search_unwind_table_name = STRINGIFY(UNW_OBJ(search_unwind_table));
+static char *find_dyn_list_name = STRINGIFY(UNW_OBJ(find_dyn_list));
+
+static struct libunwind_descr *
+libunwind_descr (struct gdbarch *gdbarch)
+{
+  return gdbarch_data (gdbarch, libunwind_descr_handle);
+}
+
+static void *
+libunwind_descr_init (struct gdbarch *gdbarch)
+{
+  struct libunwind_descr *descr = GDBARCH_OBSTACK_ZALLOC (gdbarch,
+							  struct libunwind_descr);
+  return descr;
+}
+
+void
+libunwind_frame_set_descr (struct gdbarch *gdbarch, struct libunwind_descr *descr)
+{
+  struct libunwind_descr *arch_descr;
+
+  gdb_assert (gdbarch != NULL);
+
+  arch_descr = gdbarch_data (gdbarch, libunwind_descr_handle);
+
+  if (arch_descr == NULL)
+    {
+      /* First time here.  Must initialize data area.  */
+      arch_descr = libunwind_descr_init (gdbarch);
+      set_gdbarch_data (gdbarch, libunwind_descr_handle, arch_descr);
+    }
+
+  /* Copy new descriptor info into arch descriptor.  */
+  arch_descr->gdb2uw = descr->gdb2uw;
+  arch_descr->uw2gdb = descr->uw2gdb;
+  arch_descr->is_fpreg = descr->is_fpreg;
+  arch_descr->accessors = descr->accessors;
+}
+
+static struct libunwind_frame_cache *
+libunwind_frame_cache (struct frame_info *next_frame, void **this_cache)
+{
+  unw_accessors_t *acc;
+  unw_addr_space_t as;
+  unw_word_t fp;
+  unw_regnum_t uw_sp_regnum;
+  struct libunwind_frame_cache *cache;
+  struct libunwind_descr *descr;
+  int i, ret;
+
+  if (*this_cache)
+    return *this_cache;
+
+  /* Allocate a new cache.  */
+  cache = FRAME_OBSTACK_ZALLOC (struct libunwind_frame_cache);
+
+  cache->func_addr = frame_func_unwind (next_frame);
+
+  /* Get a libunwind cursor to the previous frame.  We do this by initializing
+     a cursor.  Libunwind treats a new cursor as the top of stack and will get
+     the current register set via the libunwind register accessor.  Now, we
+     provide the platform-specific accessors and we set up the register accessor to use
+     the frame register unwinding interfaces so that we properly get the registers for
+     the current frame rather than the top.  We then use the  unw_step function to 
+     move the libunwind cursor back one frame.  We can later use this cursor to find previous 
+     registers via the unw_get_reg interface which will invoke libunwind's special logic.  */
+  descr = libunwind_descr (get_frame_arch (next_frame));
+  acc = descr->accessors;
+  as =  unw_create_addr_space_p (acc,
+				 TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
+				 ? __BIG_ENDIAN
+				 : __LITTLE_ENDIAN);
+
+  unw_init_remote_p (&cache->cursor, as, next_frame);
+  unw_step_p (&cache->cursor);
+
+  /* To get base address, get sp from previous frame.  */
+  uw_sp_regnum = descr->gdb2uw (SP_REGNUM);
+  ret = unw_get_reg_p (&cache->cursor, uw_sp_regnum, &fp);
+  if (ret < 0)
+    error ("Can't get libunwind sp register.");
+
+  cache->base = (CORE_ADDR)fp;
+
+  *this_cache = cache;
+  return cache;
+}
+
+unw_word_t 
+libunwind_find_dyn_list (unw_addr_space_t as, void *table, size_t table_size,
+			 unw_word_t segbase, unw_word_t gp, void *arg)
+{
+  return unw_find_dyn_list_p (as, table, table_size, segbase, gp, arg);
+}
+
+static const struct frame_unwind libunwind_frame_unwind =
+{
+  NORMAL_FRAME,
+  libunwind_frame_this_id,
+  libunwind_frame_prev_register
+};
+
+/* Verify if there is sufficient libunwind information for the frame to use
+   libunwind frame unwinding.  */
+const struct frame_unwind *
+libunwind_frame_sniffer (struct frame_info *next_frame)
+{
+  unw_cursor_t cursor;
+  unw_accessors_t *acc;
+  unw_addr_space_t as;
+  struct libunwind_descr *descr;
+  int i, ret;
+
+  /* To test for libunwind unwind support, initialize a cursor to the current frame and try to back
+     up.  We use this same method when setting up the frame cache (see libunwind_frame_cache()).
+     If libunwind returns success for this operation, it means that it has found sufficient
+     libunwind unwinding information to do so.  */
+
+  descr = libunwind_descr (get_frame_arch (next_frame));
+  acc = descr->accessors;
+  as =  unw_create_addr_space_p (acc,
+				 TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
+				 ? __BIG_ENDIAN
+				 : __LITTLE_ENDIAN);
+
+  ret = unw_init_remote_p (&cursor, as, next_frame);
+
+  if (ret >= 0)
+    ret = unw_step_p (&cursor);
+
+  if (ret < 0)
+    return NULL;
+
+  return &libunwind_frame_unwind;
+}
+
+void
+libunwind_frame_this_id (struct frame_info *next_frame, void **this_cache,
+		      struct frame_id *this_id)
+{
+  struct libunwind_frame_cache *cache =
+    libunwind_frame_cache (next_frame, this_cache);
+
+  (*this_id) = frame_id_build (cache->base, cache->func_addr);
+}
+
+void
+libunwind_frame_prev_register (struct frame_info *next_frame, void **this_cache,
+			       int regnum, int *optimizedp,
+			       enum lval_type *lvalp, CORE_ADDR *addrp,
+			       int *realnump, void *valuep)
+{
+  struct libunwind_frame_cache *cache =
+    libunwind_frame_cache (next_frame, this_cache);
+
+  void *ptr;
+  unw_cursor_t *c;
+  unw_save_loc_t sl;
+  int i, ret;
+  unw_word_t intval;
+  unw_fpreg_t fpval;
+  unw_regnum_t uw_regnum;
+  struct libunwind_descr *descr;
+
+  /* Convert from gdb register number to libunwind register number.  */
+  descr = libunwind_descr (get_frame_arch (next_frame));
+  uw_regnum = descr->gdb2uw (regnum);
+
+  gdb_assert (regnum >= 0);
+
+  if (!target_has_registers)
+    error ("No registers.");
+
+  *optimizedp = 0;
+  *addrp = 0;
+  *lvalp = not_lval;
+  *realnump = -1;
+
+  memset (valuep, 0, register_size (current_gdbarch, regnum));
+
+  if (uw_regnum < 0)
+    return;
+
+  /* To get the previous register, we use the libunwind register APIs with
+     the cursor we have already pushed back to the previous frame.  */
+
+  if (descr->is_fpreg (uw_regnum))
+    {
+      ret = unw_get_fpreg_p (&cache->cursor, uw_regnum, &fpval);
+      ptr = &fpval;
+    }
+  else
+    {
+      ret = unw_get_reg_p (&cache->cursor, uw_regnum, &intval);
+      ptr = &intval;
+    }
+
+  if (ret < 0)
+    return;
+
+  memcpy (valuep, ptr, register_size (current_gdbarch, regnum));
+
+  if (unw_get_saveloc_p (&cache->cursor, uw_regnum, &sl) < 0)
+    return;
+
+  switch (sl.type)
+    {
+    case UNW_SLT_NONE:
+      *optimizedp = 1;
+      break;
+
+    case UNW_SLT_MEMORY:
+      *lvalp = lval_memory;
+      *addrp = sl.u.addr;
+      break;
+
+    case UNW_SLT_REG:
+      *lvalp = lval_register;
+      *realnump = regnum;
+      break;
+    }
+} 
+
+CORE_ADDR
+libunwind_frame_base_address (struct frame_info *next_frame, void **this_cache)
+{
+  struct libunwind_frame_cache *cache =
+    libunwind_frame_cache (next_frame, this_cache);
+
+  return cache->base;
+}
+
+/* The following is a glue routine to call the libunwind unwind table
+   search function to get unwind information for a specified ip address.  */ 
+int
+libunwind_search_unwind_table (void *as, long ip, void *di,
+			       void *pi, int need_unwind_info, void *args)
+{
+  return unw_search_unwind_table_p (*(unw_addr_space_t *)as, (unw_word_t )ip, 
+				    di, pi, need_unwind_info, args);
+}
+
+static int
+libunwind_load (void)
+{
+  void *handle;
+
+  handle = dlopen (LIBUNWIND_SO, RTLD_NOW);
+  if (handle == NULL)
+    return 0;
+
+  /* Initialize pointers to the dynamic library functions we will use.  */
+
+  unw_get_reg_p = dlsym (handle, get_reg_name);
+  if (unw_get_reg_p == NULL)
+    return 0;
+
+  unw_get_fpreg_p = dlsym (handle, get_fpreg_name);
+  if (unw_get_fpreg_p == NULL)
+    return 0;
+
+  unw_get_saveloc_p = dlsym (handle, get_saveloc_name);
+  if (unw_get_saveloc_p == NULL)
+    return 0;
+
+  unw_step_p = dlsym (handle, step_name);
+  if (unw_step_p == NULL)
+    return 0;
+
+  unw_init_remote_p = dlsym (handle, init_remote_name);
+  if (unw_init_remote_p == NULL)
+    return 0;
+
+  unw_create_addr_space_p = dlsym (handle, create_addr_space_name);
+  if (unw_create_addr_space_p == NULL)
+    return 0;
+
+  unw_search_unwind_table_p = dlsym (handle, search_unwind_table_name);
+  if (unw_search_unwind_table_p == NULL)
+    return 0;
+
+  unw_find_dyn_list_p = dlsym (handle, find_dyn_list_name);
+  if (unw_find_dyn_list_p == NULL)
+    return 0;
+   
+  return 1;
+}
+
+int
+libunwind_is_initialized (void)
+{
+  return libunwind_initialized;
+}
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+void _initialize_libunwind_frame (void);
+
+void
+_initialize_libunwind_frame (void)
+{
+  libunwind_descr_handle = register_gdbarch_data (libunwind_descr_init);
+
+  libunwind_initialized = libunwind_load ();
+}