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old-cross-binutils/gdb/solib.c
Kevin Buettner 749499cbc4 solib.c relocation improvements
2000-10-30 23:31:17 +00:00

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/* Handle shared libraries for GDB, the GNU Debugger.
Copyright 1990, 91, 92, 93, 94, 95, 96, 98, 1999, 2000
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 <sys/types.h>
#include <fcntl.h>
#include "gdb_string.h"
#include "symtab.h"
#include "bfd.h"
#include "symfile.h"
#include "objfiles.h"
#include "gdbcore.h"
#include "command.h"
#include "target.h"
#include "frame.h"
#include "gdb_regex.h"
#include "inferior.h"
#include "environ.h"
#include "language.h"
#include "gdbcmd.h"
#include "solist.h"
/* external data declarations */
/* FIXME: gdbarch needs to control this variable */
struct target_so_ops *current_target_so_ops;
/* local data declarations */
static struct so_list *so_list_head; /* List of known shared objects */
static int solib_cleanup_queued = 0; /* make_run_cleanup called */
/* Local function prototypes */
static void do_clear_solib (PTR);
/* If non-zero, this is a prefix that will be added to the front of the name
shared libraries with an absolute filename for loading. */
static char *solib_absolute_prefix = NULL;
/* If non-empty, this is a search path for loading non-absolute shared library
symbol files. This takes precedence over the environment variables PATH
and LD_LIBRARY_PATH. */
static char *solib_search_path = NULL;
/*
LOCAL FUNCTION
solib_map_sections -- open bfd and build sections for shared lib
SYNOPSIS
static int solib_map_sections (struct so_list *so)
DESCRIPTION
Given a pointer to one of the shared objects in our list
of mapped objects, use the recorded name to open a bfd
descriptor for the object, build a section table, and then
relocate all the section addresses by the base address at
which the shared object was mapped.
FIXMES
In most (all?) cases the shared object file name recorded in the
dynamic linkage tables will be a fully qualified pathname. For
cases where it isn't, do we really mimic the systems search
mechanism correctly in the below code (particularly the tilde
expansion stuff?).
*/
static int
solib_map_sections (PTR arg)
{
struct so_list *so = (struct so_list *) arg; /* catch_errors bogon */
char *filename;
char *scratch_pathname;
int scratch_chan;
struct section_table *p;
struct cleanup *old_chain;
bfd *abfd;
filename = tilde_expand (so->so_name);
if (solib_absolute_prefix && ROOTED_P (filename))
/* Prefix shared libraries with absolute filenames with
SOLIB_ABSOLUTE_PREFIX. */
{
char *pfxed_fn;
int pfx_len;
pfx_len = strlen (solib_absolute_prefix);
/* Remove trailing slashes. */
while (pfx_len > 0 && SLASH_P (solib_absolute_prefix[pfx_len - 1]))
pfx_len--;
pfxed_fn = xmalloc (pfx_len + strlen (filename) + 1);
strcpy (pfxed_fn, solib_absolute_prefix);
strcat (pfxed_fn, filename);
free (filename);
filename = pfxed_fn;
}
old_chain = make_cleanup (free, filename);
scratch_chan = -1;
if (solib_search_path)
scratch_chan = openp (solib_search_path,
1, filename, O_RDONLY, 0, &scratch_pathname);
if (scratch_chan < 0)
scratch_chan = openp (get_in_environ (inferior_environ, "PATH"),
1, filename, O_RDONLY, 0, &scratch_pathname);
if (scratch_chan < 0)
{
scratch_chan = openp (get_in_environ
(inferior_environ, "LD_LIBRARY_PATH"),
1, filename, O_RDONLY, 0, &scratch_pathname);
}
if (scratch_chan < 0)
{
perror_with_name (filename);
}
/* Leave scratch_pathname allocated. abfd->name will point to it. */
abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan);
if (!abfd)
{
close (scratch_chan);
error ("Could not open `%s' as an executable file: %s",
scratch_pathname, bfd_errmsg (bfd_get_error ()));
}
/* Leave bfd open, core_xfer_memory and "info files" need it. */
so->abfd = abfd;
abfd->cacheable = true;
/* copy full path name into so_name, so that later symbol_file_add can find
it */
if (strlen (scratch_pathname) >= SO_NAME_MAX_PATH_SIZE)
error ("Full path name length of shared library exceeds SO_NAME_MAX_PATH_SIZE in so_list structure.");
strcpy (so->so_name, scratch_pathname);
if (!bfd_check_format (abfd, bfd_object))
{
error ("\"%s\": not in executable format: %s.",
scratch_pathname, bfd_errmsg (bfd_get_error ()));
}
if (build_section_table (abfd, &so->sections, &so->sections_end))
{
error ("Can't find the file sections in `%s': %s",
bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
}
for (p = so->sections; p < so->sections_end; p++)
{
/* Relocate the section binding addresses as recorded in the shared
object's file by the base address to which the object was actually
mapped. */
TARGET_SO_RELOCATE_SECTION_ADDRESSES (so, p);
if (STREQ (p->the_bfd_section->name, ".text"))
{
so->textsection = p;
}
}
/* Free the file names, close the file now. */
do_cleanups (old_chain);
return (1);
}
/* LOCAL FUNCTION
free_so --- free a `struct so_list' object
SYNOPSIS
void free_so (struct so_list *so)
DESCRIPTION
Free the storage associated with the `struct so_list' object SO.
If we have opened a BFD for SO, close it.
The caller is responsible for removing SO from whatever list it is
a member of. If we have placed SO's sections in some target's
section table, the caller is responsible for removing them.
This function doesn't mess with objfiles at all. If there is an
objfile associated with SO that needs to be removed, the caller is
responsible for taking care of that. */
void
free_so (struct so_list *so)
{
char *bfd_filename = 0;
if (so->sections)
free (so->sections);
if (so->abfd)
{
bfd_filename = bfd_get_filename (so->abfd);
if (! bfd_close (so->abfd))
warning ("cannot close \"%s\": %s",
bfd_filename, bfd_errmsg (bfd_get_error ()));
}
if (bfd_filename)
free (bfd_filename);
TARGET_SO_FREE_SO (so);
free (so);
}
/* A small stub to get us past the arg-passing pinhole of catch_errors. */
static int
symbol_add_stub (PTR arg)
{
register struct so_list *so = (struct so_list *) arg; /* catch_errs bogon */
struct section_addr_info *sap;
/* Have we already loaded this shared object? */
ALL_OBJFILES (so->objfile)
{
if (strcmp (so->objfile->name, so->so_name) == 0)
return 1;
}
sap = build_section_addr_info_from_section_table (so->sections,
so->sections_end);
so->objfile = symbol_file_add (so->so_name, so->from_tty,
sap, 0, OBJF_SHARED);
free_section_addr_info (sap);
return (1);
}
/* LOCAL FUNCTION
update_solib_list --- synchronize GDB's shared object list with inferior's
SYNOPSIS
void update_solib_list (int from_tty, struct target_ops *TARGET)
Extract the list of currently loaded shared objects from the
inferior, and compare it with the list of shared objects currently
in GDB's so_list_head list. Edit so_list_head to bring it in sync
with the inferior's new list.
If we notice that the inferior has unloaded some shared objects,
free any symbolic info GDB had read about those shared objects.
Don't load symbolic info for any new shared objects; just add them
to the list, and leave their symbols_loaded flag clear.
If FROM_TTY is non-null, feel free to print messages about what
we're doing.
If TARGET is non-null, add the sections of all new shared objects
to TARGET's section table. Note that this doesn't remove any
sections for shared objects that have been unloaded, and it
doesn't check to see if the new shared objects are already present in
the section table. But we only use this for core files and
processes we've just attached to, so that's okay. */
void
update_solib_list (int from_tty, struct target_ops *target)
{
struct so_list *inferior = TARGET_SO_CURRENT_SOS ();
struct so_list *gdb, **gdb_link;
/* If we are attaching to a running process for which we
have not opened a symbol file, we may be able to get its
symbols now! */
if (attach_flag &&
symfile_objfile == NULL)
catch_errors (TARGET_SO_OPEN_SYMBOL_FILE_OBJECT, (PTR) &from_tty,
"Error reading attached process's symbol file.\n",
RETURN_MASK_ALL);
/* Since this function might actually add some elements to the
so_list_head list, arrange for it to be cleaned up when
appropriate. */
if (!solib_cleanup_queued)
{
make_run_cleanup (do_clear_solib, NULL);
solib_cleanup_queued = 1;
}
/* GDB and the inferior's dynamic linker each maintain their own
list of currently loaded shared objects; we want to bring the
former in sync with the latter. Scan both lists, seeing which
shared objects appear where. There are three cases:
- A shared object appears on both lists. This means that GDB
knows about it already, and it's still loaded in the inferior.
Nothing needs to happen.
- A shared object appears only on GDB's list. This means that
the inferior has unloaded it. We should remove the shared
object from GDB's tables.
- A shared object appears only on the inferior's list. This
means that it's just been loaded. We should add it to GDB's
tables.
So we walk GDB's list, checking each entry to see if it appears
in the inferior's list too. If it does, no action is needed, and
we remove it from the inferior's list. If it doesn't, the
inferior has unloaded it, and we remove it from GDB's list. By
the time we're done walking GDB's list, the inferior's list
contains only the new shared objects, which we then add. */
gdb = so_list_head;
gdb_link = &so_list_head;
while (gdb)
{
struct so_list *i = inferior;
struct so_list **i_link = &inferior;
/* Check to see whether the shared object *gdb also appears in
the inferior's current list. */
while (i)
{
if (! strcmp (gdb->so_original_name, i->so_original_name))
break;
i_link = &i->next;
i = *i_link;
}
/* If the shared object appears on the inferior's list too, then
it's still loaded, so we don't need to do anything. Delete
it from the inferior's list, and leave it on GDB's list. */
if (i)
{
*i_link = i->next;
free_so (i);
gdb_link = &gdb->next;
gdb = *gdb_link;
}
/* If it's not on the inferior's list, remove it from GDB's tables. */
else
{
*gdb_link = gdb->next;
/* Unless the user loaded it explicitly, free SO's objfile. */
if (gdb->objfile && ! (gdb->objfile->flags & OBJF_USERLOADED))
free_objfile (gdb->objfile);
/* Some targets' section tables might be referring to
sections from so->abfd; remove them. */
remove_target_sections (gdb->abfd);
free_so (gdb);
gdb = *gdb_link;
}
}
/* Now the inferior's list contains only shared objects that don't
appear in GDB's list --- those that are newly loaded. Add them
to GDB's shared object list. */
if (inferior)
{
struct so_list *i;
/* Add the new shared objects to GDB's list. */
*gdb_link = inferior;
/* Fill in the rest of each of the `struct so_list' nodes. */
for (i = inferior; i; i = i->next)
{
i->from_tty = from_tty;
/* Fill in the rest of the `struct so_list' node. */
catch_errors (solib_map_sections, i,
"Error while mapping shared library sections:\n",
RETURN_MASK_ALL);
}
/* If requested, add the shared objects' sections to the the
TARGET's section table. */
if (target)
{
int new_sections;
/* Figure out how many sections we'll need to add in total. */
new_sections = 0;
for (i = inferior; i; i = i->next)
new_sections += (i->sections_end - i->sections);
if (new_sections > 0)
{
int space = target_resize_to_sections (target, new_sections);
for (i = inferior; i; i = i->next)
{
int count = (i->sections_end - i->sections);
memcpy (target->to_sections + space,
i->sections,
count * sizeof (i->sections[0]));
space += count;
}
}
}
}
}
/* GLOBAL FUNCTION
solib_add -- read in symbol info for newly added shared libraries
SYNOPSIS
void solib_add (char *pattern, int from_tty, struct target_ops *TARGET)
DESCRIPTION
Read in symbolic information for any shared objects whose names
match PATTERN. (If we've already read a shared object's symbol
info, leave it alone.) If PATTERN is zero, read them all.
FROM_TTY and TARGET are as described for update_solib_list, above. */
void
solib_add (char *pattern, int from_tty, struct target_ops *target)
{
struct so_list *gdb;
if (pattern)
{
char *re_err = re_comp (pattern);
if (re_err)
error ("Invalid regexp: %s", re_err);
}
update_solib_list (from_tty, target);
/* Walk the list of currently loaded shared libraries, and read
symbols for any that match the pattern --- or any whose symbols
aren't already loaded, if no pattern was given. */
{
int any_matches = 0;
int loaded_any_symbols = 0;
for (gdb = so_list_head; gdb; gdb = gdb->next)
if (! pattern || re_exec (gdb->so_name))
{
any_matches = 1;
if (gdb->symbols_loaded)
{
if (from_tty)
printf_unfiltered ("Symbols already loaded for %s\n",
gdb->so_name);
}
else
{
if (catch_errors
(symbol_add_stub, gdb,
"Error while reading shared library symbols:\n",
RETURN_MASK_ALL))
{
if (from_tty)
printf_unfiltered ("Loaded symbols for %s\n",
gdb->so_name);
gdb->symbols_loaded = 1;
loaded_any_symbols = 1;
}
}
}
if (from_tty && pattern && ! any_matches)
printf_unfiltered
("No loaded shared libraries match the pattern `%s'.\n", pattern);
if (loaded_any_symbols)
{
/* Getting new symbols may change our opinion about what is
frameless. */
reinit_frame_cache ();
TARGET_SO_SPECIAL_SYMBOL_HANDLING ();
}
}
}
/*
LOCAL FUNCTION
info_sharedlibrary_command -- code for "info sharedlibrary"
SYNOPSIS
static void info_sharedlibrary_command ()
DESCRIPTION
Walk through the shared library list and print information
about each attached library.
*/
static void
info_sharedlibrary_command (char *ignore, int from_tty)
{
register struct so_list *so = NULL; /* link map state variable */
int header_done = 0;
int addr_width;
char *addr_fmt;
int arch_size;
if (exec_bfd == NULL)
{
printf_unfiltered ("No executable file.\n");
return;
}
arch_size = bfd_get_arch_size (exec_bfd);
/* Default to 32-bit in case of failure (non-elf). */
if (arch_size == 32 || arch_size == -1)
{
addr_width = 8 + 4;
addr_fmt = "08l";
}
else if (arch_size == 64)
{
addr_width = 16 + 4;
addr_fmt = "016l";
}
update_solib_list (from_tty, 0);
for (so = so_list_head; so; so = so->next)
{
if (so->so_name[0])
{
if (!header_done)
{
printf_unfiltered ("%-*s%-*s%-12s%s\n", addr_width, "From",
addr_width, "To", "Syms Read",
"Shared Object Library");
header_done++;
}
printf_unfiltered ("%-*s", addr_width,
so->textsection != NULL
? local_hex_string_custom (
(unsigned long) so->textsection->addr,
addr_fmt)
: "");
printf_unfiltered ("%-*s", addr_width,
so->textsection != NULL
? local_hex_string_custom (
(unsigned long) so->textsection->endaddr,
addr_fmt)
: "");
printf_unfiltered ("%-12s", so->symbols_loaded ? "Yes" : "No");
printf_unfiltered ("%s\n", so->so_name);
}
}
if (so_list_head == NULL)
{
printf_unfiltered ("No shared libraries loaded at this time.\n");
}
}
/*
GLOBAL FUNCTION
solib_address -- check to see if an address is in a shared lib
SYNOPSIS
char * solib_address (CORE_ADDR address)
DESCRIPTION
Provides a hook for other gdb routines to discover whether or
not a particular address is within the mapped address space of
a shared library.
For example, this routine is called at one point to disable
breakpoints which are in shared libraries that are not currently
mapped in.
*/
char *
solib_address (CORE_ADDR address)
{
register struct so_list *so = 0; /* link map state variable */
for (so = so_list_head; so; so = so->next)
{
struct section_table *p;
for (p = so->sections; p < so->sections_end; p++)
{
if (p->addr <= address && address < p->endaddr)
return (so->so_name);
}
}
return (0);
}
/* Called by free_all_symtabs */
void
clear_solib (void)
{
/* This function is expected to handle ELF shared libraries. It is
also used on Solaris, which can run either ELF or a.out binaries
(for compatibility with SunOS 4), both of which can use shared
libraries. So we don't know whether we have an ELF executable or
an a.out executable until the user chooses an executable file.
ELF shared libraries don't get mapped into the address space
until after the program starts, so we'd better not try to insert
breakpoints in them immediately. We have to wait until the
dynamic linker has loaded them; we'll hit a bp_shlib_event
breakpoint (look for calls to create_solib_event_breakpoint) when
it's ready.
SunOS shared libraries seem to be different --- they're present
as soon as the process begins execution, so there's no need to
put off inserting breakpoints. There's also nowhere to put a
bp_shlib_event breakpoint, so if we put it off, we'll never get
around to it.
So: disable breakpoints only if we're using ELF shared libs. */
if (exec_bfd != NULL
&& bfd_get_flavour (exec_bfd) != bfd_target_aout_flavour)
disable_breakpoints_in_shlibs (1);
while (so_list_head)
{
struct so_list *so = so_list_head;
so_list_head = so->next;
free_so (so);
}
TARGET_SO_CLEAR_SOLIB ();
}
static void
do_clear_solib (PTR dummy)
{
solib_cleanup_queued = 0;
clear_solib ();
}
/* GLOBAL FUNCTION
solib_create_inferior_hook -- shared library startup support
SYNOPSIS
void solib_create_inferior_hook()
DESCRIPTION
When gdb starts up the inferior, it nurses it along (through the
shell) until it is ready to execute it's first instruction. At this
point, this function gets called via expansion of the macro
SOLIB_CREATE_INFERIOR_HOOK. */
void
solib_create_inferior_hook (void)
{
TARGET_SO_SOLIB_CREATE_INFERIOR_HOOK ();
}
/*
LOCAL FUNCTION
sharedlibrary_command -- handle command to explicitly add library
SYNOPSIS
static void sharedlibrary_command (char *args, int from_tty)
DESCRIPTION
*/
static void
sharedlibrary_command (char *args, int from_tty)
{
dont_repeat ();
solib_add (args, from_tty, (struct target_ops *) 0);
}
void
_initialize_solib (void)
{
add_com ("sharedlibrary", class_files, sharedlibrary_command,
"Load shared object library symbols for files matching REGEXP.");
add_info ("sharedlibrary", info_sharedlibrary_command,
"Status of loaded shared object libraries.");
add_show_from_set
(add_set_cmd ("auto-solib-add", class_support, var_zinteger,
(char *) &auto_solib_add,
"Set autoloading of shared library symbols.\n\
If nonzero, symbols from all shared object libraries will be loaded\n\
automatically when the inferior begins execution or when the dynamic linker\n\
informs gdb that a new library has been loaded. Otherwise, symbols\n\
must be loaded manually, using `sharedlibrary'.",
&setlist),
&showlist);
add_show_from_set
(add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
(char *) &solib_absolute_prefix,
"Set prefix for loading absolute shared library symbol files.\n\
For other (relative) files, you can add values using `set solib-search-path'.",
&setlist),
&showlist);
add_show_from_set
(add_set_cmd ("solib-search-path", class_support, var_string,
(char *) &solib_search_path,
"Set the search path for loading non-absolute shared library symbol files.\n\
This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
&setlist),
&showlist);
}
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