+#ifndef SVR4_SHARED_LIBS
+
+ struct minimal_symbol *msymbol;
+ CORE_ADDR address = 0;
+ char **symbolp;
+
+ /* For SunOS, we want to limit the search for the debug base symbol to the
+ executable being debugged, since there is a duplicate named symbol in the
+ shared library. We don't want the shared library versions. */
+
+ for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++)
+ {
+ msymbol = lookup_minimal_symbol (*symbolp, NULL, symfile_objfile);
+ if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
+ {
+ address = SYMBOL_VALUE_ADDRESS (msymbol);
+ return (address);
+ }
+ }
+ return (0);
+
+#else /* SVR4_SHARED_LIBS */
+
+ /* Check to see if we have a currently valid address, and if so, avoid
+ doing all this work again and just return the cached address. If
+ we have no cached address, try to locate it in the dynamic info
+ section for ELF executables. */
+
+ if (debug_base == 0)
+ {
+ if (exec_bfd != NULL
+ && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
+ debug_base = elf_locate_base ();
+#ifdef HANDLE_SVR4_EXEC_EMULATORS
+ /* Try it the hard way for emulated executables. */
+ else if (inferior_pid != 0 && target_has_execution)
+ proc_iterate_over_mappings (look_for_base);
+#endif
+ }
+ return (debug_base);
+
+#endif /* !SVR4_SHARED_LIBS */
+
+}
+
+/*
+
+ LOCAL FUNCTION
+
+ first_link_map_member -- locate first member in dynamic linker's map
+
+ SYNOPSIS
+
+ static CORE_ADDR first_link_map_member (void)
+
+ DESCRIPTION
+
+ Find the first element in the inferior's dynamic link map, and
+ return its address in the inferior. This function doesn't copy the
+ link map entry itself into our address space; current_sos actually
+ does the reading. */
+
+static CORE_ADDR
+first_link_map_member ()
+{
+ CORE_ADDR lm = 0;
+
+#ifndef SVR4_SHARED_LIBS
+
+ read_memory (debug_base, (char *) &dynamic_copy, sizeof (dynamic_copy));
+ if (dynamic_copy.ld_version >= 2)
+ {
+ /* It is a version that we can deal with, so read in the secondary
+ structure and find the address of the link map list from it. */
+ read_memory (SOLIB_EXTRACT_ADDRESS (dynamic_copy.ld_un.ld_2),
+ (char *) &ld_2_copy, sizeof (struct link_dynamic_2));
+ lm = SOLIB_EXTRACT_ADDRESS (ld_2_copy.ld_loaded);
+ }
+
+#else /* SVR4_SHARED_LIBS */
+
+ read_memory (debug_base, (char *) &debug_copy, sizeof (struct r_debug));
+ /* FIXME: Perhaps we should validate the info somehow, perhaps by
+ checking r_version for a known version number, or r_state for
+ RT_CONSISTENT. */
+ lm = SOLIB_EXTRACT_ADDRESS (debug_copy.r_map);
+
+#endif /* !SVR4_SHARED_LIBS */
+
+ return (lm);
+}
+
+#ifdef SVR4_SHARED_LIBS
+/*
+
+ LOCAL FUNCTION
+
+ open_symbol_file_object
+
+ SYNOPSIS
+
+ void open_symbol_file_object (int from_tty)
+
+ DESCRIPTION
+
+ If no open symbol file, attempt to locate and open the main symbol
+ file. On SVR4 systems, this is the first link map entry. If its
+ name is here, we can open it. Useful when attaching to a process
+ without first loading its symbol file.
+
+ */
+
+static int
+open_symbol_file_object (from_ttyp)
+ int *from_ttyp; /* sneak past catch_errors */
+{
+ CORE_ADDR lm;
+ struct link_map lmcopy;
+ char *filename;
+ int errcode;
+
+ if (symfile_objfile)
+ if (!query ("Attempt to reload symbols from process? "))
+ return 0;
+
+ if ((debug_base = locate_base ()) == 0)
+ return 0; /* failed somehow... */
+
+ /* First link map member should be the executable. */
+ if ((lm = first_link_map_member ()) == 0)
+ return 0; /* failed somehow... */
+
+ /* Read from target memory to GDB. */
+ read_memory (lm, (void *) &lmcopy, sizeof (lmcopy));
+
+ if (lmcopy.l_name == 0)
+ return 0; /* no filename. */
+
+ /* Now fetch the filename from target memory. */
+ target_read_string (SOLIB_EXTRACT_ADDRESS (lmcopy.l_name), &filename,
+ MAX_PATH_SIZE - 1, &errcode);
+ if (errcode)
+ {
+ warning ("failed to read exec filename from attached file: %s",
+ safe_strerror (errcode));
+ return 0;
+ }
+
+ make_cleanup (free, filename);
+ /* Have a pathname: read the symbol file. */
+ symbol_file_command (filename, *from_ttyp);
+
+ return 1;
+}
+#endif /* SVR4_SHARED_LIBS */
+
+
+/* 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. */
+
+static 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);
+
+ free (so);
+}
+
+
+/* On some systems, the only way to recognize the link map entry for
+ the main executable file is by looking at its name. Return
+ non-zero iff SONAME matches one of the known main executable names. */
+
+static int
+match_main (soname)
+ char *soname;
+{
+ char **mainp;
+
+ for (mainp = main_name_list; *mainp != NULL; mainp++)
+ {
+ if (strcmp (soname, *mainp) == 0)
+ return (1);
+ }
+
+ return (0);
+}
+
+
+/* LOCAL FUNCTION
+
+ current_sos -- build a list of currently loaded shared objects
+
+ SYNOPSIS
+
+ struct so_list *current_sos ()
+
+ DESCRIPTION
+
+ Build a list of `struct so_list' objects describing the shared
+ objects currently loaded in the inferior. This list does not
+ include an entry for the main executable file.
+
+ Note that we only gather information directly available from the
+ inferior --- we don't examine any of the shared library files
+ themselves. The declaration of `struct so_list' says which fields
+ we provide values for. */
+
+static struct so_list *
+current_sos ()
+{
+ CORE_ADDR lm;
+ struct so_list *head = 0;
+ struct so_list **link_ptr = &head;
+
+ /* Make sure we've looked up the inferior's dynamic linker's base
+ structure. */
+ if (! debug_base)
+ {
+ debug_base = locate_base ();
+
+ /* If we can't find the dynamic linker's base structure, this
+ must not be a dynamically linked executable. Hmm. */
+ if (! debug_base)
+ return 0;
+ }
+
+ /* Walk the inferior's link map list, and build our list of
+ `struct so_list' nodes. */
+ lm = first_link_map_member ();
+ while (lm)
+ {
+ struct so_list *new
+ = (struct so_list *) xmalloc (sizeof (struct so_list));
+ struct cleanup *old_chain = make_cleanup (free, new);
+ memset (new, 0, sizeof (*new));
+
+ new->lmaddr = lm;
+ read_memory (lm, (char *) &(new->lm), sizeof (struct link_map));
+
+ lm = LM_NEXT (new);
+
+ /* For SVR4 versions, the first entry in the link map is for the
+ inferior executable, so we must ignore it. For some versions of
+ SVR4, it has no name. For others (Solaris 2.3 for example), it
+ does have a name, so we can no longer use a missing name to
+ decide when to ignore it. */
+ if (IGNORE_FIRST_LINK_MAP_ENTRY (new))
+ free_so (new);
+ else
+ {
+ int errcode;
+ char *buffer;
+
+ /* Extract this shared object's name. */
+ target_read_string (LM_NAME (new), &buffer,
+ MAX_PATH_SIZE - 1, &errcode);
+ if (errcode != 0)
+ {
+ warning ("current_sos: Can't read pathname for load map: %s\n",
+ safe_strerror (errcode));
+ }
+ else
+ {
+ strncpy (new->so_name, buffer, MAX_PATH_SIZE - 1);
+ new->so_name[MAX_PATH_SIZE - 1] = '\0';
+ free (buffer);
+ strcpy (new->so_original_name, new->so_name);
+ }
+
+ /* If this entry has no name, or its name matches the name
+ for the main executable, don't include it in the list. */
+ if (! new->so_name[0]
+ || match_main (new->so_name))
+ free_so (new);
+ else
+ {
+ new->next = 0;
+ *link_ptr = new;
+ link_ptr = &new->next;
+ }
+ }
+
+ discard_cleanups (old_chain);
+ }
+
+ return head;
+}
+
+
+/* A small stub to get us past the arg-passing pinhole of catch_errors. */
+
+static int
+symbol_add_stub (arg)
+ PTR arg;
+{
+ register struct so_list *so = (struct so_list *) arg; /* catch_errs bogon */
+ struct section_addr_info *sap;
+ CORE_ADDR lowest_addr = 0;
+ int lowest_index;
+ asection *lowest_sect = NULL;
+
+ /* Have we already loaded this shared object? */
+ ALL_OBJFILES (so->objfile)
+ {
+ if (strcmp (so->objfile->name, so->so_name) == 0)
+ return 1;
+ }
+
+ /* Find the shared object's text segment. */
+ if (so->textsection)
+ {
+ lowest_addr = so->textsection->addr;
+ lowest_sect = bfd_get_section_by_name (so->abfd, ".text");
+ lowest_index = lowest_sect->index;
+ }
+ else if (so->abfd != NULL)
+ {
+ /* If we didn't find a mapped non zero sized .text section, set
+ up lowest_addr so that the relocation in symbol_file_add does
+ no harm. */
+ lowest_sect = bfd_get_section_by_name (so->abfd, ".text");
+ if (lowest_sect == NULL)
+ bfd_map_over_sections (so->abfd, find_lowest_section,
+ (PTR) &lowest_sect);
+ if (lowest_sect)
+ {
+ lowest_addr = bfd_section_vma (so->abfd, lowest_sect)
+ + LM_ADDR (so);
+ lowest_index = lowest_sect->index;
+ }
+ }
+
+ sap = build_section_addr_info_from_section_table (so->sections,
+ so->sections_end);
+
+ sap->other[lowest_index].addr = lowest_addr;
+
+ 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 = current_sos ();
+ struct so_list *gdb, **gdb_link;
+
+#ifdef SVR4_SHARED_LIBS
+ /* 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 (open_symbol_file_object, (PTR) &from_tty,
+ "Error reading attached process's symbol file.\n",
+ RETURN_MASK_ALL);
+
+#endif SVR4_SHARED_LIBS
+
+ /* 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 ();
+
+ 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 (ignore, from_tty)
+ 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_elf_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,
+ local_hex_string_custom ((unsigned long) LM_ADDR (so),
+ addr_fmt));
+ printf_unfiltered ("%-*s", addr_width,
+ local_hex_string_custom ((unsigned long) so->lmend,
+ 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. Any address between the base mapping address
+ and the first address beyond the end of the last mapping, is
+ considered to be within the shared library address space, for
+ our purposes.
+
+ 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 (address)
+ CORE_ADDR address;
+{
+ register struct so_list *so = 0; /* link map state variable */
+
+ for (so = so_list_head; so; so = so->next)
+ {
+ if (LM_ADDR (so) <= address && address < so->lmend)
+ return (so->so_name);
+ }
+
+ return (0);
+}
+
+/* Called by free_all_symtabs */
+
+void
+clear_solib ()
+{
+ /* 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);
+ }
+
+ debug_base = 0;
+}
+
+static void
+do_clear_solib (dummy)
+ PTR dummy;
+{
+ solib_cleanup_queued = 0;
+ clear_solib ();
+}
+
+#ifdef SVR4_SHARED_LIBS
+
+/* Return 1 if PC lies in the dynamic symbol resolution code of the
+ SVR4 run time loader. */
+
+static CORE_ADDR interp_text_sect_low;
+static CORE_ADDR interp_text_sect_high;
+static CORE_ADDR interp_plt_sect_low;
+static CORE_ADDR interp_plt_sect_high;
+
+int
+in_svr4_dynsym_resolve_code (pc)
+ CORE_ADDR pc;
+{
+ return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
+ || (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
+ || in_plt_section (pc, NULL));
+}
+#endif
+
+/*
+
+ LOCAL FUNCTION
+
+ disable_break -- remove the "mapping changed" breakpoint
+
+ SYNOPSIS
+
+ static int disable_break ()
+
+ DESCRIPTION
+
+ Removes the breakpoint that gets hit when the dynamic linker
+ completes a mapping change.
+
+ */
+
+#ifndef SVR4_SHARED_LIBS
+
+static int
+disable_break ()
+{
+ int status = 1;
+
+#ifndef SVR4_SHARED_LIBS
+
+ int in_debugger = 0;
+
+ /* Read the debugger structure from the inferior to retrieve the
+ address of the breakpoint and the original contents of the
+ breakpoint address. Remove the breakpoint by writing the original
+ contents back. */
+
+ read_memory (debug_addr, (char *) &debug_copy, sizeof (debug_copy));
+
+ /* Set `in_debugger' to zero now. */
+
+ write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger));
+
+ breakpoint_addr = SOLIB_EXTRACT_ADDRESS (debug_copy.ldd_bp_addr);
+ write_memory (breakpoint_addr, (char *) &debug_copy.ldd_bp_inst,
+ sizeof (debug_copy.ldd_bp_inst));
+
+#else /* SVR4_SHARED_LIBS */
+
+ /* Note that breakpoint address and original contents are in our address
+ space, so we just need to write the original contents back. */
+
+ if (memory_remove_breakpoint (breakpoint_addr, shadow_contents) != 0)
+ {
+ status = 0;
+ }
+
+#endif /* !SVR4_SHARED_LIBS */
+
+ /* For the SVR4 version, we always know the breakpoint address. For the
+ SunOS version we don't know it until the above code is executed.
+ Grumble if we are stopped anywhere besides the breakpoint address. */
+
+ if (stop_pc != breakpoint_addr)
+ {
+ warning ("stopped at unknown breakpoint while handling shared libraries");
+ }
+
+ return (status);
+}
+
+#endif /* #ifdef SVR4_SHARED_LIBS */
+
+/*
+
+ LOCAL FUNCTION
+
+ enable_break -- arrange for dynamic linker to hit breakpoint
+
+ SYNOPSIS
+
+ int enable_break (void)
+
+ DESCRIPTION
+
+ Both the SunOS and the SVR4 dynamic linkers have, as part of their
+ debugger interface, support for arranging for the inferior to hit
+ a breakpoint after mapping in the shared libraries. This function
+ enables that breakpoint.
+
+ For SunOS, there is a special flag location (in_debugger) which we
+ set to 1. When the dynamic linker sees this flag set, it will set
+ a breakpoint at a location known only to itself, after saving the
+ original contents of that place and the breakpoint address itself,
+ in it's own internal structures. When we resume the inferior, it
+ will eventually take a SIGTRAP when it runs into the breakpoint.
+ We handle this (in a different place) by restoring the contents of
+ the breakpointed location (which is only known after it stops),
+ chasing around to locate the shared libraries that have been
+ loaded, then resuming.
+
+ For SVR4, the debugger interface structure contains a member (r_brk)
+ which is statically initialized at the time the shared library is
+ built, to the offset of a function (_r_debug_state) which is guaran-
+ teed to be called once before mapping in a library, and again when
+ the mapping is complete. At the time we are examining this member,
+ it contains only the unrelocated offset of the function, so we have
+ to do our own relocation. Later, when the dynamic linker actually
+ runs, it relocates r_brk to be the actual address of _r_debug_state().
+
+ The debugger interface structure also contains an enumeration which
+ is set to either RT_ADD or RT_DELETE prior to changing the mapping,
+ depending upon whether or not the library is being mapped or unmapped,
+ and then set to RT_CONSISTENT after the library is mapped/unmapped.
+ */
+
+static int
+enable_break ()
+{
+ int success = 0;
+
+#ifndef SVR4_SHARED_LIBS
+
+ int j;
+ int in_debugger;
+
+ /* Get link_dynamic structure */
+
+ j = target_read_memory (debug_base, (char *) &dynamic_copy,
+ sizeof (dynamic_copy));
+ if (j)
+ {
+ /* unreadable */
+ return (0);
+ }
+
+ /* Calc address of debugger interface structure */
+
+ debug_addr = SOLIB_EXTRACT_ADDRESS (dynamic_copy.ldd);
+
+ /* Calc address of `in_debugger' member of debugger interface structure */
+
+ flag_addr = debug_addr + (CORE_ADDR) ((char *) &debug_copy.ldd_in_debugger -
+ (char *) &debug_copy);
+
+ /* Write a value of 1 to this member. */
+
+ in_debugger = 1;
+ write_memory (flag_addr, (char *) &in_debugger, sizeof (in_debugger));
+ success = 1;
+
+#else /* SVR4_SHARED_LIBS */
+
+#ifdef BKPT_AT_SYMBOL
+
+ struct minimal_symbol *msymbol;
+ char **bkpt_namep;
+ asection *interp_sect;
+
+ /* First, remove all the solib event breakpoints. Their addresses
+ may have changed since the last time we ran the program. */
+ remove_solib_event_breakpoints ();
+
+#ifdef SVR4_SHARED_LIBS
+ interp_text_sect_low = interp_text_sect_high = 0;
+ interp_plt_sect_low = interp_plt_sect_high = 0;
+
+ /* Find the .interp section; if not found, warn the user and drop
+ into the old breakpoint at symbol code. */
+ interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
+ if (interp_sect)
+ {
+ unsigned int interp_sect_size;
+ char *buf;
+ CORE_ADDR load_addr;
+ bfd *tmp_bfd;
+ CORE_ADDR sym_addr = 0;
+
+ /* Read the contents of the .interp section into a local buffer;
+ the contents specify the dynamic linker this program uses. */
+ interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
+ buf = alloca (interp_sect_size);
+ bfd_get_section_contents (exec_bfd, interp_sect,
+ buf, 0, interp_sect_size);
+
+ /* Now we need to figure out where the dynamic linker was
+ loaded so that we can load its symbols and place a breakpoint
+ in the dynamic linker itself.
+
+ This address is stored on the stack. However, I've been unable
+ to find any magic formula to find it for Solaris (appears to
+ be trivial on GNU/Linux). Therefore, we have to try an alternate
+ mechanism to find the dynamic linker's base address. */
+ tmp_bfd = bfd_openr (buf, gnutarget);
+ if (tmp_bfd == NULL)
+ goto bkpt_at_symbol;
+
+ /* Make sure the dynamic linker's really a useful object. */
+ if (!bfd_check_format (tmp_bfd, bfd_object))
+ {
+ warning ("Unable to grok dynamic linker %s as an object file", buf);
+ bfd_close (tmp_bfd);
+ goto bkpt_at_symbol;
+ }
+
+ /* We find the dynamic linker's base address by examining the
+ current pc (which point at the entry point for the dynamic
+ linker) and subtracting the offset of the entry point. */
+ load_addr = read_pc () - tmp_bfd->start_address;
+
+ /* Record the relocated start and end address of the dynamic linker
+ text and plt section for in_svr4_dynsym_resolve_code. */
+ interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
+ if (interp_sect)
+ {
+ interp_text_sect_low =
+ bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
+ interp_text_sect_high =
+ interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect);
+ }
+ interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
+ if (interp_sect)
+ {
+ interp_plt_sect_low =
+ bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
+ interp_plt_sect_high =
+ interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect);
+ }
+
+ /* Now try to set a breakpoint in the dynamic linker. */
+ for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
+ {
+ sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
+ if (sym_addr != 0)
+ break;
+ }
+
+ /* We're done with the temporary bfd. */
+ bfd_close (tmp_bfd);
+
+ if (sym_addr != 0)
+ {
+ create_solib_event_breakpoint (load_addr + sym_addr);
+ return 1;
+ }
+
+ /* For whatever reason we couldn't set a breakpoint in the dynamic
+ linker. Warn and drop into the old code. */
+ bkpt_at_symbol:
+ warning ("Unable to find dynamic linker breakpoint function.\nGDB will be unable to debug shared library initializers\nand track explicitly loaded dynamic code.");
+ }
+#endif
+
+ /* Scan through the list of symbols, trying to look up the symbol and
+ set a breakpoint there. Terminate loop when we/if we succeed. */
+
+ breakpoint_addr = 0;
+ for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
+ {
+ msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
+ if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
+ {
+ create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol));
+ return 1;
+ }
+ }
+
+ /* Nothing good happened. */
+ success = 0;
+
+#endif /* BKPT_AT_SYMBOL */
+
+#endif /* !SVR4_SHARED_LIBS */
+
+ return (success);
+}
+
+/*
+
+ 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.
+
+ For SunOS executables, this first instruction is typically the
+ one at "_start", or a similar text label, regardless of whether
+ the executable is statically or dynamically linked. The runtime
+ startup code takes care of dynamically linking in any shared
+ libraries, once gdb allows the inferior to continue.
+
+ For SVR4 executables, this first instruction is either the first
+ instruction in the dynamic linker (for dynamically linked
+ executables) or the instruction at "start" for statically linked
+ executables. For dynamically linked executables, the system
+ first exec's /lib/libc.so.N, which contains the dynamic linker,
+ and starts it running. The dynamic linker maps in any needed
+ shared libraries, maps in the actual user executable, and then
+ jumps to "start" in the user executable.
+
+ For both SunOS shared libraries, and SVR4 shared libraries, we
+ can arrange to cooperate with the dynamic linker to discover the
+ names of shared libraries that are dynamically linked, and the
+ base addresses to which they are linked.
+
+ This function is responsible for discovering those names and
+ addresses, and saving sufficient information about them to allow
+ their symbols to be read at a later time.
+
+ FIXME
+
+ Between enable_break() and disable_break(), this code does not
+ properly handle hitting breakpoints which the user might have
+ set in the startup code or in the dynamic linker itself. Proper
+ handling will probably have to wait until the implementation is
+ changed to use the "breakpoint handler function" method.
+
+ Also, what if child has exit()ed? Must exit loop somehow.
+ */
+
+void
+solib_create_inferior_hook ()
+{
+ /* If we are using the BKPT_AT_SYMBOL code, then we don't need the base
+ yet. In fact, in the case of a SunOS4 executable being run on
+ Solaris, we can't get it yet. current_sos will get it when it needs
+ it. */
+#if !(defined (SVR4_SHARED_LIBS) && defined (BKPT_AT_SYMBOL))
+ if ((debug_base = locate_base ()) == 0)
+ {
+ /* Can't find the symbol or the executable is statically linked. */
+ return;
+ }
+#endif
+
+ if (!enable_break ())
+ {
+ warning ("shared library handler failed to enable breakpoint");
+ return;
+ }
+
+#if !defined(SVR4_SHARED_LIBS) || defined(_SCO_DS)
+ /* SCO and SunOS need the loop below, other systems should be using the
+ special shared library breakpoints and the shared library breakpoint
+ service routine.
+
+ Now run the target. It will eventually hit the breakpoint, at
+ which point all of the libraries will have been mapped in and we
+ can go groveling around in the dynamic linker structures to find
+ out what we need to know about them. */
+
+ clear_proceed_status ();
+ stop_soon_quietly = 1;
+ stop_signal = TARGET_SIGNAL_0;
+ do
+ {
+ target_resume (-1, 0, stop_signal);
+ wait_for_inferior ();
+ }
+ while (stop_signal != TARGET_SIGNAL_TRAP);
+ stop_soon_quietly = 0;
+
+#if !defined(_SCO_DS)
+ /* We are now either at the "mapping complete" breakpoint (or somewhere
+ else, a condition we aren't prepared to deal with anyway), so adjust
+ the PC as necessary after a breakpoint, disable the breakpoint, and
+ add any shared libraries that were mapped in. */
+
+ if (DECR_PC_AFTER_BREAK)
+ {
+ stop_pc -= DECR_PC_AFTER_BREAK;
+ write_register (PC_REGNUM, stop_pc);
+ }
+
+ if (!disable_break ())
+ {
+ warning ("shared library handler failed to disable breakpoint");
+ }
+
+ if (auto_solib_add)
+ solib_add ((char *) 0, 0, (struct target_ops *) 0);
+#endif /* ! _SCO_DS */
+#endif
+}
+
+/*
+
+ LOCAL FUNCTION
+
+ special_symbol_handling -- additional shared library symbol handling
+
+ SYNOPSIS
+
+ void special_symbol_handling ()
+
+ DESCRIPTION
+
+ Once the symbols from a shared object have been loaded in the usual
+ way, we are called to do any system specific symbol handling that
+ is needed.
+
+ For SunOS4, this consists of grunging around in the dynamic
+ linkers structures to find symbol definitions for "common" symbols
+ and adding them to the minimal symbol table for the runtime common
+ objfile.
+
+ */
+
+static void
+special_symbol_handling ()
+{
+#ifndef SVR4_SHARED_LIBS
+ int j;
+
+ if (debug_addr == 0)
+ {
+ /* Get link_dynamic structure */
+
+ j = target_read_memory (debug_base, (char *) &dynamic_copy,
+ sizeof (dynamic_copy));
+ if (j)
+ {
+ /* unreadable */
+ return;
+ }
+
+ /* Calc address of debugger interface structure */
+ /* FIXME, this needs work for cross-debugging of core files
+ (byteorder, size, alignment, etc). */
+
+ debug_addr = SOLIB_EXTRACT_ADDRESS (dynamic_copy.ldd);
+ }
+
+ /* Read the debugger structure from the inferior, just to make sure
+ we have a current copy. */
+
+ j = target_read_memory (debug_addr, (char *) &debug_copy,
+ sizeof (debug_copy));
+ if (j)
+ return; /* unreadable */
+
+ /* Get common symbol definitions for the loaded object. */
+
+ if (debug_copy.ldd_cp)
+ {
+ solib_add_common_symbols (SOLIB_EXTRACT_ADDRESS (debug_copy.ldd_cp));
+ }
+
+#endif /* !SVR4_SHARED_LIBS */
+}
+
+
+/*
+
+ 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 (args, from_tty)
+ char *args;
+ int from_tty;
+{
+ dont_repeat ();
+ solib_add (args, from_tty, (struct target_ops *) 0);
+}
+
+#endif /* HAVE_LINK_H */
+
+void
+_initialize_solib ()
+{
+#ifdef HAVE_LINK_H
+
+ 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);
+
+#endif /* HAVE_LINK_H */