Re: RFA: libunwind basic support

["J. Johnston" <jjohnstn@redhat.com>]

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Please see latest patch attached which addresses questions below.  I have added 
a configuration option: --enable-libunwind per your suggestion.

Ok so far?  I have to wait for Kevin to get through my intermediate patch before 
I can send you the ia64-tdep.c side of the libunwind patch.

2003-10-15  Jeff Johnston  <jjohnstn@redhat.com>
	* libunwind-frame.c: New file.
	* libunwind-frame.h: New file.
	* configure.in: Add --enable-libunwind option support.
	* configure: Regenerated.
	* Makefile.in: Add support for libunwind-frame.o.
	* config.in: Regenerated.


J. Johnston wrote:
> Andrew Cagney wrote:
> 
>> Jeff,
>>
>> Is it possible to post (or commit to a branch) the other 
>> (work-in-progress?) parts to this change?
>> Ignoring a few nits, this code appears to be going in the right 
>> direction, however its hard to tell without seeing things in toto.
>>
>>> The attached patch adds basic libunwind frame support.  I will be 
>>> shortly submitting an ia64-tdep.c patch which works in conjunction 
>>> with this patch.  The libunwind code is protected by looking for the 
>>> libunwind header files to compile.  At runtime, the libunwind frame 
>>> sniffer will fail if either the libunwind library cannot be 
>>> dynamically loaded or the frame in question does not have proper 
>>> libunwind info.
>>
>>
>>
>> First some straight legal questions:
>>
>> - from where can libunwind be obtained?
>>
> 
> http://www.hpl.hp.com/research/linux/libunwind/
> 
>> - who owns it?
>>
> 
> Hewlitt-Packard
> 
>> - what are its licence terms, and are they GPL compatible?
>>
> 
> It has a BSD-like license.  Yes, it is GPL compatible.
> 
> 
> Copyright (c) 2002 Hewlett-Packard Co.
> 
> Permission is hereby granted, free of charge, to any person obtaining
> a copy of this software and associated documentation files (the
> "Software"), to deal in the Software without restriction, including
> without limitation the rights to use, copy, modify, merge, publish,
> distribute, sublicense, and/or sell copies of the Software, and to
> permit persons to whom the Software is furnished to do so, subject to
> the following conditions:
> 
> The above copyright notice and this permission notice shall be
> included in all copies or substantial portions of the Software.
> 
> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
> NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
> LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
> OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
> WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
> 
>> - is it considered a "system library" (like libc, or libthread_db)?
>>
> 
> I would have to say no.  It is currently an optional library.  This is 
> one of the reasons I chose to use a dynamic load mechanism.
> 
>> - have you used, or refered to David Mossberger's [sp] old libunwind 
>> patch (it was eventually contributed to the FSF).
>>
> 
> No.  Not in this code.
> 
>>> For configuration I have added checks for libunwind.h and 
>>> libunwind-ia64.h as this is being added for ia64 support only at 
>>> present.  Regarding testing, I have this code working with my ia64 
>>> changes.  I have tested on systems with the libunwind-0.92 
>>> library/headers installed and not installed.
>>
>>
>>
>> I see, to make this optional, you've wrapped the code in #ifdef 
>> HAVE_LIBUNWIND_H, and then modified the Makefile so that it is 
>> unconditionally built :-(
>>
>> These files should only be linked in when when needed, or at least 
>> only when there's a libunwind around.  Have a look at --with-mmalloc 
>> and --with-sysroot for how to implement the option --with-libunwind 
>> which lets the user force their inclusion; and --disable-gdbcli, 
>> --enable-tui, and --enable-sim for idea's on how to make linking the 
>> object files optional.
>>
> 
> I'll take a look.  The only thing this allows a user to do is to build 
> gdb on a system that it can legimately build libunwind support and 
> purposely disable it at configuration.  Can you disable dwarf2 cfi 
> support?  If not, why would you want to do this for libunwind which is a 
> similar level of functionality?
> 
>>> 2003-10-15  Jeff Johnston  <jjohnstn@redhat.com>
>>>
>>>     * libunwind-frame.c: New file.
>>>     * libunwind-frame.h: New file.
>>>     * configure.in: Add checks for libunwind.h and libunwind-ia64.h.
>>>     * configure: Regenerated.
>>>     * Makefile.in: Add support for libunwind-frame.o.
>>>     * config.in: Regenerated.
>>
>>
>>
>> Without seeing the rest of the code I'm really not in a position to 
>> comment on the technical design.
>>
>> However, a quick glance did through up a few nits.  I'm noting them 
>> now, so that, hopefully an additional round trip can be avoided later.
>>
>> +   Contributed by Jeff Johnston
>>
>> Legal nit.  "Written by Jeff Johnston, contributed by Red Hat Inc.", 
>> you don't have an assignment on file.
>>
> 
> Will change.
> 
> 
>>> +void
>>> +libunwind_set_descr_handle (void *handle)
>>> +{
>>> +  libunwind_descr_handle = handle;
>>> +}
>>
>>
>>
>> I don't understand this.  A guess is that this is trying to implement 
>> a mechanism that lets an external module set this modules 
>> per-architecture data?  If that is the case, then can you have a look 
>> at the set_gdbarch_data doco and regrroups.c's reggroup_add method for 
>> how to do this?
>>
> 
> I did look at said functionality originally.  I ran into a problem which 
> this solved.  I will have to look again to see what the problem was 
> because I don't remember off-hand.
> 
>> +#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_saveloc));
>> +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));
>>
>> I don't understand this.  A guess is that UNW_OBJ() is doing something 
>> evil (use "include/sym-cat.h") to those names and having the array 
>> (use "static const char <name>[] = ..." and local to libunwind_load) 
>> makes ones debugging life much easier?  If this is the case, can you 
>> add some commentary?
>>
> 
> Yes.  The libunwind code is slightly ugly with respect to the fact that 
> the function names are not aliased with generic names.  They all have 
> platform prefixes so I must spell them out.  Function names are 
> generated automatically using the UNW_OBJ macro.
> 
>> +  memset (valuep, 0, DEPRECATED_REGISTER_RAW_SIZE (regnum));
>>
>> ? you probably want register_size().
>>
> 
> Yes.
> 
>> +static int
>> +libunwind_load (void)
>> +{
>> +  void *handle;
>> +
>> +  handle = dlopen (LIBUNWIND_SO, RTLD_NOW);
>> +  if (handle == NULL)
>> +    return 0;
>>
>> For thread-db.c I added code that printed out the library that was 
>> loaded.  Should the same be done here?   Note that, due to querks with 
>> the way GDB starts up, the message needs to be delayed - see 
>> thread-db.c for more details.
>>
> 
> IMO, there is little value-add.  There are architecture messages that 
> will print out whether libunwind is being used or not.  The problems 
> with libthread-db don't exist in this case.
> 
>> +const struct frame_unwind *
>> +libunwind_frame_sniffer (struct frame_info *next_frame);
>>
>> can you please write the declaration thus:
>>
>> const struct frame_unwind *libunwind_frame_sniffer (....
>>
>> so that it is consistent with the rest of GDB.
>>
> 
> Ok.  I copied the declaration from below and forget to rejoin the lines.
> 
> -- Jeff J.
> 
> 

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Index: libunwind-frame.c
===================================================================
RCS file: libunwind-frame.c
diff -N libunwind-frame.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ libunwind-frame.c	22 Oct 2003 23:36:21 -0000
@@ -0,0 +1,376 @@
+/* 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"
+
+#ifdef HAVE_LIBUNWIND_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;
+};
+
+#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_saveloc));
+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 cursor to the previous frame.  We do this by initializing
+     a cursor and stepping back to the frame level prior to the one we are 
+     currently in.  */
+  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
+};
+
+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;
+
+  /* Get a cursor to the previous frame.  We do this by initializing
+     a cursor and stepping back to the frame level prior to the one we are 
+     currently in.  */
+  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;
+
+  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;
+
+  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;
+}
+
+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;
+}
+
+#endif /* HAVE_LIBUNWIND_H  */
+
+/* Provide a prototype to silence -Wmissing-prototypes.  */
+void _initialize_libunwind_frame (void);
+
+void
+_initialize_libunwind_frame (void)
+{
+#ifdef HAVE_LIBUNWIND_H
+  libunwind_descr_handle = register_gdbarch_data (libunwind_descr_init);
+
+  libunwind_initialized = libunwind_load ();
+#endif  
+}
Index: libunwind-frame.h
===================================================================
RCS file: libunwind-frame.h
diff -N libunwind-frame.h
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ libunwind-frame.h	22 Oct 2003 23:36:21 -0000
@@ -0,0 +1,63 @@
+/* Frame unwinder for frames with libunwind frame information.
+
+   Copyright 2003 Free Software Foundation, Inc.
+
+   Contributed by Jeff Johnston.
+
+   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.  */
+
+#ifdef HAVE_LIBUNWIND_H
+
+#ifndef LIBUNWIND_FRAME_H
+#define LIBUNWIND_FRAME_H 1
+
+#include "libunwind.h"
+
+struct frame_info;
+
+struct libunwind_descr
+{
+  int (*gdb2uw) (int);
+  int (*uw2gdb) (int);
+  int (*is_fpreg) (int);
+  void *accessors;
+};
+
+const struct frame_unwind *libunwind_frame_sniffer (struct frame_info *next_frame);
+
+void libunwind_frame_set_descr (struct gdbarch *arch, struct libunwind_descr *descr);
+
+void libunwind_frame_this_id (struct frame_info *next_frame, void **this_cache,
+			      struct frame_id *this_id);
+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);
+CORE_ADDR libunwind_frame_base_address (struct frame_info *next_frame, void **this_cache);
+
+int libunwind_is_initialized (void);
+
+int libunwind_search_unwind_table (void *as, long ip, void *di,
+				   void *pi, int need_unwind_info, void *args);
+
+unw_word_t libunwind_find_dyn_list (unw_addr_space_t, void *, size_t,
+				    unw_word_t, unw_word_t, void *);
+     
+#endif /* libunwind-frame.h */
+
+#endif /* HAVE_LIBUNWIND_H  */
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.458
diff -u -r1.458 Makefile.in
--- Makefile.in	18 Oct 2003 18:41:22 -0000	1.458
+++ Makefile.in	22 Oct 2003 23:36:21 -0000
@@ -701,6 +701,7 @@
 jv_lang_h = jv-lang.h
 kod_h = kod.h
 language_h = language.h
+libunwind_frame_h = libunwind-frame.h
 linespec_h = linespec.h
 linux_nat_h = linux-nat.h
 m2_lang_h = m2-lang.h
@@ -1271,6 +1272,7 @@
 	i386gnu-nat.c i386gnu-tdep.c \
 	ia64-linux-nat.c ia64-linux-tdep.c ia64-tdep.c \
 	infptrace.c inftarg.c irix4-nat.c irix5-nat.c \
+	libunwind-frame.c \
 	lynx-nat.c m3-nat.c \
 	m68hc11-tdep.c \
 	m68k-tdep.c \
@@ -1897,7 +1899,7 @@
 	$(arch_utils_h) $(floatformat_h) $(regcache_h) $(reggroups_h) \
 	$(frame_h) $(frame_base_h) $(frame_unwind_h) $(doublest_h) \
 	$(value_h) $(gdb_assert_h) $(objfiles_h) $(elf_common_h) \
-	$(elf_bfd_h) $(dis_asm_h)
+	$(elf_bfd_h) $(dis_asm_h) $(libunwind_frame_h)
 infcall.o: infcall.c $(defs_h) $(breakpoint_h) $(target_h) $(regcache_h) \
 	$(inferior_h) $(gdb_assert_h) $(block_h) $(gdbcore_h) $(language_h) \
 	$(symfile_h) $(gdbcmd_h) $(command_h) $(gdb_string_h) $(infcall_h)
@@ -1945,6 +1947,10 @@
 language.o: language.c $(defs_h) $(gdb_string_h) $(symtab_h) $(gdbtypes_h) \
 	$(value_h) $(gdbcmd_h) $(expression_h) $(language_h) $(target_h) \
 	$(parser_defs_h) $(jv_lang_h) $(demangle_h)
+libunwind-frame.o: libunwind-frame.c $(defs_h) \
+	$(frame_h) $(frame_base_h) $(frame_unwind_h) $(gdbcore_h) \
+	$(gdbtypes_h) $(symtab_h) $(objfiles_h) $(regcache_h) \
+	$(gdb_assert_h) $(gdb_string_h) $(complaints_h) $(libunwind_frame_h)
 linespec.o: linespec.c $(defs_h) $(symtab_h) $(frame_h) $(command_h) \
 	$(symfile_h) $(objfiles_h) $(source_h) $(demangle_h) $(value_h) \
 	$(completer_h) $(cp_abi_h) $(parser_defs_h) $(block_h) \
Index: configure.in
===================================================================
RCS file: /cvs/src/src/gdb/configure.in,v
retrieving revision 1.132
diff -u -r1.132 configure.in
--- configure.in	3 Sep 2003 15:02:48 -0000	1.132
+++ configure.in	22 Oct 2003 23:36:21 -0000
@@ -192,6 +192,33 @@
     enable_gdbtk=no ;;
 esac
 
+# Enable libunwind support.
+AC_ARG_ENABLE(libunwind,
+[  --enable-libunwind          enable libunwind frame unwinding support],
+  [case $enableval in
+    yes | no)
+      ;;
+    *)
+      AC_MSG_ERROR([bad value $enableval for --enable-libunwind]) ;;
+  esac])
+if test x"$enable_libunwind" = xyes; then
+  # We currently only support libunwind on selected platforms.
+  case $host in
+    ia64*)
+      ;;
+    *)
+      AC_MSG_WARN([libunwind isn't supported on $host; disabling])
+      enable_libunwind=no ;;
+  esac
+  if test x"$enable_libunwind" = xyes; then
+    AC_CHECK_HEADERS(libunwind.h)
+    AC_CHECK_HEADERS(libunwind-ia64.h)
+    CONFIG_OBS="$CONFIG_OBS libunwind-frame.o"
+    CONFIG_DEPS="$CONFIG_DEPS libunwind-frame.o"
+    CONFIG_SRCS="$CONFIG_SRCS libunwind-frame.c"
+  fi
+fi
+
 # Profiling support.
 AC_ARG_ENABLE(profiling,
 [  --enable-profiling      enable profiling of GDB],