[PATCH RFC] Split SunOS/SVR4 shared library support

Kevin Buettner
2001-09-29T11:23:00Z

At the present time, the file solib-svr4.c contains support for both
SVR4 shared libraries (which is also used by Linux and newer *BSD
releases) and SunOS4 shared libraries (which is also used by older
*BSD releases). It implements this dual support in a single file by
using ifdefs controlled by the preprocessor symbol SVR4_SHARED_LIBS.

This macro, SVR4_SHARED_LIBS, is preventing the SVR4 shared library
support contained in solib-svr4.c from being truly host independent.
There are currently some host/target configurations where SVR4_SHARED_LIBS
is not defined when it ought to be which ends up causing the host's
link.h to be pulled in (even on hosts which don't have <link.h>).

It would be possible (and even correct) to define SVR4_SHARED_LIBS in
the various tm-*.h files which need it, but gdb development is
attempting to winnow down the amount of stuff contained in these files
with the ultimate goal of eliminating them entirely. Therefore, it
seems that a more reasonable thing to do is to split the SunOS support
out of solib-svr4.c into a separate file.

This decision has a minor drawback. There is some code shared by
the two implementations which must be duplicated. The most notable
example of this is svr4_current_sos(). In the process of splitting
the support, however, I found that I was able to simplify this code
somewhat (at least for SunOS) since this function no longer needs to
worry about implementing support for a different mechanism. Also,
I think maintenance will become easier since it will be possible to
(e.g) make changes to the SVR4 version without having to worry about
whether the SunOS version is adversely impacted.

The patch below splits the SVR4/SunOS shared library support into
separate files. The file solib-svr4.c now contains only SVR4 support
while solib-sunos.c contains SunOS support. I've left many of the
comments which compare/contrast the ways that SVR4 and SunOS do things
alone since I think these aid in understanding the overall purpose of
some of the functions.

I think I've also fixed the necessary bits of the configury to know
about solib-sunos.o.

The only problem I found while updating the configury is that
config/i386/nm-fbsd.h (FreeBSD) uses a conditional expression to
decide whether SVR4 or SunOS shared library support is needed, causing
SVR4_SHARED_LIBS to be defined (or not) in the process. However, I've
left solib-svr4.o in the NATDEPFILES line of config/i386/fbsd.mh.
This means that an older FreeBSD system which wants SunOS shlib
support won't be able to find it in solib-svr4.o. NetBSD solves this
problem by having separate *.m[ht] for ELF (which implies SVR4 shared
libs) and a.out (which implies SunOS shared libs). If necessary, we
can update FreeBSD to use the same mechanism. It may also be possible
to arrange to include both modules and somehow dynamically select
between the two (which'd be handy if you need to be able to debug both
types of binaries).

I've tested this patch by building / testing a native GDB on the
following platforms:

SunOS shared libs:
i386-unknown-netbsd1.4
sparc-sun-sunos4.1.4

SVR4 shared libs:
i686-pc-linux-gnu
ia64-unknown-linux
i386-unknown-netbsdelf1.5
i486-unknown-sysv5UnixWare7.1.1
powerpc-unknown-linux-gnu
sparc-sun-solaris2.5.1
i386-unknown-freebsd4.2
i386-pc-solaris2.8

Here's a heads up for some follow-on activities after this patch is
committed:

- elimination of SVR4_SHARED_LIBS from the rest of the sources
- move solib-svr4.o to the TDEPFILES lines for all targets

I'll wait a few days for comments before committing the following
changes...

* Makefile.in (ALLDEPFILES): Add solib-svr4.c and solib-sunos.c
to this list.
(solib-sunos.o): Add dependencies.
(solib-svr4.o): Revise dependencies.
* solib-svr4.c: Remove SunOS shared library support.
* solib-sunos.c: New file, created from solib-svr4.c, which still
contains SunOS shared library support, but no SVR4 support.

* config/i386/nbsd.mh (NATDEPFILES): Remove solib-svr4.o and
solib-legacy.o from this list. Add solib-sunos.o.
* config/i386/sun386.mt (TDEPFILES): Likewise.
* config/m68k/nbsd.mh (NATDEPFILES): Likewise.
* config/m68k/sun2os4.mt (TDEPFILES): Likewise.
* config/m68k/sun3os4.mt (TDEPFILES): Likewise.
* config/ns32k/nbsd.mh (NATDEPFILES): Likewise.
* config/sparc/nbsd.mh (NATDEPFILES): Likewise.
* config/sparc/sun4os4.mt (TDEPFILES): Likewise.

Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.116
diff -u -p -r1.116 Makefile.in
--- Makefile.in 2001/09/21 12:19:15 1.116
+++ Makefile.in 2001/09/29 18:15:37
@@ -1181,7 +1181,7 @@ ALLDEPFILES = 29k-share/udi/udip2soc.c 2
remote-udi.c remote-vx.c remote-vx29k.c \
rs6000-nat.c rs6000-tdep.c \
ser-go32.c ser-pipe.c ser-tcp.c \
- sh-tdep.c solib.c sparc-nat.c \
+ sh-tdep.c solib.c solib-svr4.c solib-sunos.c sparc-nat.c \
sparc-tdep.c sparcl-tdep.c sun3-nat.c \
symm-tdep.c symm-nat.c \
vax-tdep.c \
@@ -1961,9 +1961,11 @@ solib.o: solib.c $(command_h) $(defs_h)
objfiles.h gdb_regex.h $(symfile_h) $(target_h) $(gdb_string_h) \
solist.h $(completer_h)

-solib-svr4.o: solib-svr4.c $(command_h) $(defs_h) $(gdbcore_h) $(inferior_h) \
- objfiles.h gdb_regex.h $(symfile_h) $(target_h) $(gdb_string_h) \
- solist.h solib-svr4.h $(regcache_h)
+solib-sunos.o: solib-sunos.c $(defs_h) $(symfile_h) objfiles.h $(gdbcore_h) \
+ $(inferior_h) solist.h
+
+solib-svr4.o: solib-svr4.c $(defs_h) $(gdbcore_h) $(inferior_h) objfiles.h \
+ $(symfile_h) $(target_h) solist.h solib-svr4.h

solib-legacy.o: solib-legacy.c $(defs_h) $(gdbcore_h) solib-svr4.h

Index: solib-sunos.c
===================================================================
RCS file: solib-sunos.c
diff -N solib-sunos.c
--- /dev/null Tue May 5 13:32:27 1998
+++ solib-sunos.c Sat Sep 29 11:15:39 2001
@@ -0,0 +1,896 @@
+/* Handle SunOS shared libraries for GDB, the GNU Debugger.
+ Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
+ 2001
+ 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 <signal.h>
+#include "gdb_string.h"
+#include <sys/param.h>
+#include <fcntl.h>
+
+ /* SunOS shared libs need the nlist structure. */
+#include <a.out.h>
+#include <link.h>
+
+#include "symtab.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "objfiles.h"
+#include "gdbcore.h"
+#include "inferior.h"
+#include "solist.h"
+
+/* Link map info to include in an allocated so_list entry */
+
+struct lm_info
+ {
+ /* Pointer to copy of link map from inferior. The type is char *
+ rather than void *, so that we may use byte offsets to find the
+ various fields without the need for a cast. */
+ char *lm;
+ };
+
+
+/* Symbols which are used to locate the base of the link map structures. */
+
+static char *debug_base_symbols[] =
+{
+ "_DYNAMIC",
+ "_DYNAMIC__MGC",
+ NULL
+};
+
+static char *main_name_list[] =
+{
+ "main_$main",
+ NULL
+};
+
+/* Macro to extract an address from a solib structure.
+ When GDB is configured for some 32-bit targets (e.g. Solaris 2.7
+ sparc), BFD is configured to handle 64-bit targets, so CORE_ADDR is
+ 64 bits. We have to extract only the significant bits of addresses
+ to get the right address when accessing the core file BFD. */
+
+#define SOLIB_EXTRACT_ADDRESS(MEMBER) \
+ extract_address (&(MEMBER), sizeof (MEMBER))
+
+/* local data declarations */
+
+static struct link_dynamic dynamic_copy;
+static struct link_dynamic_2 ld_2_copy;
+static struct ld_debug debug_copy;
+static CORE_ADDR debug_addr;
+static CORE_ADDR flag_addr;
+
+#ifndef offsetof
+#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
+#endif
+#define fieldsize(TYPE, MEMBER) (sizeof (((TYPE *)0)->MEMBER))
+
+/* link map access functions */
+
+static CORE_ADDR
+LM_ADDR (struct so_list *so)
+{
+ int lm_addr_offset = offsetof (struct link_map, lm_addr);
+ int lm_addr_size = fieldsize (struct link_map, lm_addr);
+
+ return (CORE_ADDR) extract_signed_integer (so->lm_info->lm + lm_addr_offset,
+ lm_addr_size);
+}
+
+static CORE_ADDR
+LM_NEXT (struct so_list *so)
+{
+ int lm_next_offset = offsetof (struct link_map, lm_next);
+ int lm_next_size = fieldsize (struct link_map, lm_next);
+
+ return extract_address (so->lm_info->lm + lm_next_offset, lm_next_size);
+}
+
+static CORE_ADDR
+LM_NAME (struct so_list *so)
+{
+ int lm_name_offset = offsetof (struct link_map, lm_name);
+ int lm_name_size = fieldsize (struct link_map, lm_name);
+
+ return extract_address (so->lm_info->lm + lm_name_offset, lm_name_size);
+}
+
+static CORE_ADDR debug_base; /* Base of dynamic linker structures */
+
+/* Local function prototypes */
+
+static int match_main (char *);
+
+/* Allocate the runtime common object file. */
+
+static void
+allocate_rt_common_objfile (void)
+{
+ struct objfile *objfile;
+ struct objfile *last_one;
+
+ objfile = (struct objfile *) xmalloc (sizeof (struct objfile));
+ memset (objfile, 0, sizeof (struct objfile));
+ objfile->md = NULL;
+ obstack_specify_allocation (&objfile->psymbol_cache.cache, 0, 0,
+ xmalloc, xfree);
+ obstack_specify_allocation (&objfile->psymbol_obstack, 0, 0, xmalloc,
+ xfree);
+ obstack_specify_allocation (&objfile->symbol_obstack, 0, 0, xmalloc,
+ xfree);
+ obstack_specify_allocation (&objfile->type_obstack, 0, 0, xmalloc,
+ xfree);
+ objfile->name = mstrsave (objfile->md, "rt_common");
+
+ /* Add this file onto the tail of the linked list of other such files. */
+
+ objfile->next = NULL;
+ if (object_files == NULL)
+ object_files = objfile;
+ else
+ {
+ for (last_one = object_files;
+ last_one->next;
+ last_one = last_one->next);
+ last_one->next = objfile;
+ }
+
+ rt_common_objfile = objfile;
+}
+
+/* Read all dynamically loaded common symbol definitions from the inferior
+ and put them into the minimal symbol table for the runtime common
+ objfile. */
+
+static void
+solib_add_common_symbols (CORE_ADDR rtc_symp)
+{
+ struct rtc_symb inferior_rtc_symb;
+ struct nlist inferior_rtc_nlist;
+ int len;
+ char *name;
+
+ /* Remove any runtime common symbols from previous runs. */
+
+ if (rt_common_objfile != NULL && rt_common_objfile->minimal_symbol_count)
+ {
+ obstack_free (&rt_common_objfile->symbol_obstack, 0);
+ obstack_specify_allocation (&rt_common_objfile->symbol_obstack, 0, 0,
+ xmalloc, xfree);
+ rt_common_objfile->minimal_symbol_count = 0;
+ rt_common_objfile->msymbols = NULL;
+ }
+
+ init_minimal_symbol_collection ();
+ make_cleanup_discard_minimal_symbols ();
+
+ while (rtc_symp)
+ {
+ read_memory (rtc_symp,
+ (char *) &inferior_rtc_symb,
+ sizeof (inferior_rtc_symb));
+ read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb.rtc_sp),
+ (char *) &inferior_rtc_nlist,
+ sizeof (inferior_rtc_nlist));
+ if (inferior_rtc_nlist.n_type == N_COMM)
+ {
+ /* FIXME: The length of the symbol name is not available, but in the
+ current implementation the common symbol is allocated immediately
+ behind the name of the symbol. */
+ len = inferior_rtc_nlist.n_value - inferior_rtc_nlist.n_un.n_strx;
+
+ name = xmalloc (len);
+ read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_nlist.n_un.n_name),
+ name, len);
+
+ /* Allocate the runtime common objfile if necessary. */
+ if (rt_common_objfile == NULL)
+ allocate_rt_common_objfile ();
+
+ prim_record_minimal_symbol (name, inferior_rtc_nlist.n_value,
+ mst_bss, rt_common_objfile);
+ xfree (name);
+ }
+ rtc_symp = SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb.rtc_next);
+ }
+
+ /* Install any minimal symbols that have been collected as the current
+ minimal symbols for the runtime common objfile. */
+
+ install_minimal_symbols (rt_common_objfile);
+}
+
+
+/*
+
+ LOCAL FUNCTION
+
+ locate_base -- locate the base address of dynamic linker structs
+
+ SYNOPSIS
+
+ CORE_ADDR locate_base (void)
+
+ DESCRIPTION
+
+ For both the SunOS and SVR4 shared library implementations, if the
+ inferior executable has been linked dynamically, there is a single
+ address somewhere in the inferior's data space which is the key to
+ locating all of the dynamic linker's runtime structures. This
+ address is the value of the debug base symbol. The job of this
+ function is to find and return that address, or to return 0 if there
+ is no such address (the executable is statically linked for example).
+
+ For SunOS, the job is almost trivial, since the dynamic linker and
+ all of it's structures are statically linked to the executable at
+ link time. Thus the symbol for the address we are looking for has
+ already been added to the minimal symbol table for the executable's
+ objfile at the time the symbol file's symbols were read, and all we
+ have to do is look it up there. Note that we explicitly do NOT want
+ to find the copies in the shared library.
+
+ The SVR4 version is a bit more complicated because the address
+ is contained somewhere in the dynamic info section. We have to go
+ to a lot more work to discover the address of the debug base symbol.
+ Because of this complexity, we cache the value we find and return that
+ value on subsequent invocations. Note there is no copy in the
+ executable symbol tables.
+
+ */
+
+static CORE_ADDR
+locate_base (void)
+{
+ 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);
+}
+
+/*
+
+ 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 (void)
+{
+ CORE_ADDR lm = 0;
+
+ 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);
+ }
+ return (lm);
+}
+
+static int
+open_symbol_file_object (void *from_ttyp)
+{
+ return 1;
+}
+
+
+/* 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 *
+sunos_current_sos (void)
+{
+ CORE_ADDR lm;
+ struct so_list *head = 0;
+ struct so_list **link_ptr = &head;
+ int errcode;
+ char *buffer;
+
+ /* 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 (xfree, new);
+
+ memset (new, 0, sizeof (*new));
+
+ new->lm_info = xmalloc (sizeof (struct lm_info));
+ make_cleanup (xfree, new->lm_info);
+
+ new->lm_info->lm = xmalloc (sizeof (struct link_map));
+ make_cleanup (xfree, new->lm_info->lm);
+ memset (new->lm_info->lm, 0, sizeof (struct link_map));
+
+ read_memory (lm, new->lm_info->lm, sizeof (struct link_map));
+
+ lm = LM_NEXT (new);
+
+ /* Extract this shared object's name. */
+ target_read_string (LM_NAME (new), &buffer,
+ SO_NAME_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, SO_NAME_MAX_PATH_SIZE - 1);
+ new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
+ xfree (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;
+}
+
+
+/* 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 (char *soname)
+{
+ char **mainp;
+
+ for (mainp = main_name_list; *mainp != NULL; mainp++)
+ {
+ if (strcmp (soname, *mainp) == 0)
+ return (1);
+ }
+
+ return (0);
+}
+
+
+static int
+sunos_in_dynsym_resolve_code (CORE_ADDR pc)
+{
+ return 0;
+}
+
+/*
+
+ 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.
+
+ */
+
+static int
+disable_break (void)
+{
+ CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */
+
+ 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));
+
+ /* 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 1;
+}
+
+
+/*
+
+ 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 (void)
+{
+ int success = 0;
+ 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;
+
+ return (success);
+}
+
+/*
+
+ 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
+sunos_special_symbol_handling (void)
+{
+ 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));
+ }
+}
+
+/* Relocate the main executable. This function should be called upon
+ stopping the inferior process at the entry point to the program.
+ The entry point from BFD is compared to the PC and if they are
+ different, the main executable is relocated by the proper amount.
+
+ As written it will only attempt to relocate executables which
+ lack interpreter sections. It seems likely that only dynamic
+ linker executables will get relocated, though it should work
+ properly for a position-independent static executable as well. */
+
+static void
+sunos_relocate_main_executable (void)
+{
+ asection *interp_sect;
+ CORE_ADDR pc = read_pc ();
+
+ /* Decide if the objfile needs to be relocated. As indicated above,
+ we will only be here when execution is stopped at the beginning
+ of the program. Relocation is necessary if the address at which
+ we are presently stopped differs from the start address stored in
+ the executable AND there's no interpreter section. The condition
+ regarding the interpreter section is very important because if
+ there *is* an interpreter section, execution will begin there
+ instead. When there is an interpreter section, the start address
+ is (presumably) used by the interpreter at some point to start
+ execution of the program.
+
+ If there is an interpreter, it is normal for it to be set to an
+ arbitrary address at the outset. The job of finding it is
+ handled in enable_break().
+
+ So, to summarize, relocations are necessary when there is no
+ interpreter section and the start address obtained from the
+ executable is different from the address at which GDB is
+ currently stopped.
+
+ [ The astute reader will note that we also test to make sure that
+ the executable in question has the DYNAMIC flag set. It is my
+ opinion that this test is unnecessary (undesirable even). It
+ was added to avoid inadvertent relocation of an executable
+ whose e_type member in the ELF header is not ET_DYN. There may
+ be a time in the future when it is desirable to do relocations
+ on other types of files as well in which case this condition
+ should either be removed or modified to accomodate the new file
+ type. (E.g, an ET_EXEC executable which has been built to be
+ position-independent could safely be relocated by the OS if
+ desired. It is true that this violates the ABI, but the ABI
+ has been known to be bent from time to time.) - Kevin, Nov 2000. ]
+ */
+
+ interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
+ if (interp_sect == NULL
+ && (bfd_get_file_flags (exec_bfd) & DYNAMIC) != 0
+ && bfd_get_start_address (exec_bfd) != pc)
+ {
+ struct cleanup *old_chain;
+ struct section_offsets *new_offsets;
+ int i, changed;
+ CORE_ADDR displacement;
+
+ /* It is necessary to relocate the objfile. The amount to
+ relocate by is simply the address at which we are stopped
+ minus the starting address from the executable.
+
+ We relocate all of the sections by the same amount. This
+ behavior is mandated by recent editions of the System V ABI.
+ According to the System V Application Binary Interface,
+ Edition 4.1, page 5-5:
+
+ ... Though the system chooses virtual addresses for
+ individual processes, it maintains the segments' relative
+ positions. Because position-independent code uses relative
+ addressesing between segments, the difference between
+ virtual addresses in memory must match the difference
+ between virtual addresses in the file. The difference
+ between the virtual address of any segment in memory and
+ the corresponding virtual address in the file is thus a
+ single constant value for any one executable or shared
+ object in a given process. This difference is the base
+ address. One use of the base address is to relocate the
+ memory image of the program during dynamic linking.
+
+ The same language also appears in Edition 4.0 of the System V
+ ABI and is left unspecified in some of the earlier editions. */
+
+ displacement = pc - bfd_get_start_address (exec_bfd);
+ changed = 0;
+
+ new_offsets = xcalloc (sizeof (struct section_offsets),
+ symfile_objfile->num_sections);
+ old_chain = make_cleanup (xfree, new_offsets);
+
+ for (i = 0; i < symfile_objfile->num_sections; i++)
+ {
+ if (displacement != ANOFFSET (symfile_objfile->section_offsets, i))
+ changed = 1;
+ new_offsets->offsets[i] = displacement;
+ }
+
+ if (changed)
+ objfile_relocate (symfile_objfile, new_offsets);
+
+ do_cleanups (old_chain);
+ }
+}
+
+/*
+
+ GLOBAL FUNCTION
+
+ sunos_solib_create_inferior_hook -- shared library startup support
+
+ SYNOPSIS
+
+ void sunos_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.
+ */
+
+static void
+sunos_solib_create_inferior_hook (void)
+{
+ /* Relocate the main executable if necessary. */
+ sunos_relocate_main_executable ();
+
+ if ((debug_base = locate_base ()) == 0)
+ {
+ /* Can't find the symbol or the executable is statically linked. */
+ return;
+ }
+
+ if (!enable_break ())
+ {
+ warning ("shared library handler failed to enable breakpoint");
+ return;
+ }
+
+ /* 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 (pid_to_ptid (-1), 0, stop_signal);
+ wait_for_inferior ();
+ }
+ while (stop_signal != TARGET_SIGNAL_TRAP);
+ stop_soon_quietly = 0;
+
+ /* 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);
+}
+
+static void
+sunos_clear_solib (void)
+{
+ debug_base = 0;
+}
+
+static void
+sunos_free_so (struct so_list *so)
+{
+ xfree (so->lm_info->lm);
+ xfree (so->lm_info);
+}
+
+static void
+sunos_relocate_section_addresses (struct so_list *so,
+ struct section_table *sec)
+{
+ sec->addr += LM_ADDR (so);
+ sec->endaddr += LM_ADDR (so);
+}
+
+static struct target_so_ops sunos_so_ops;
+
+void
+_initialize_sunos_solib (void)
+{
+ sunos_so_ops.relocate_section_addresses = sunos_relocate_section_addresses;
+ sunos_so_ops.free_so = sunos_free_so;
+ sunos_so_ops.clear_solib = sunos_clear_solib;
+ sunos_so_ops.solib_create_inferior_hook = sunos_solib_create_inferior_hook;
+ sunos_so_ops.special_symbol_handling = sunos_special_symbol_handling;
+ sunos_so_ops.current_sos = sunos_current_sos;
+ sunos_so_ops.open_symbol_file_object = open_symbol_file_object;
+ sunos_so_ops.in_dynsym_resolve_code = sunos_in_dynsym_resolve_code;
+
+ /* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */
+ current_target_so_ops = &sunos_so_ops;
+}
Index: solib-svr4.c
===================================================================
RCS file: /cvs/src/src/gdb/solib-svr4.c,v
retrieving revision 1.19
diff -u -p -r1.19 solib-svr4.c
--- solib-svr4.c 2001/09/26 07:03:13 1.19
+++ solib-svr4.c 2001/09/29 18:15:40
@@ -1,4 +1,4 @@
-/* Handle SunOS and SVR4 shared libraries for GDB, the GNU Debugger.
+/* Handle SVR4 shared libraries for GDB, the GNU Debugger.
Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
2001
Free Software Foundation, Inc.
@@ -21,38 +21,18 @@
Boston, MA 02111-1307, USA. */

#include "defs.h"
-#include "regcache.h"

-
-#include <sys/types.h>
-#include <signal.h>
-#include "gdb_string.h"
-#include <sys/param.h>
-#include <fcntl.h>
-
-#ifndef SVR4_SHARED_LIBS
- /* SunOS shared libs need the nlist structure. */
-#include <a.out.h>
-#include <link.h>
-#else
#include "elf/external.h"
#include "elf/common.h"
#include "elf/mips.h"
-#endif

#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"
#include "solib-svr4.h"
@@ -93,7 +73,6 @@ struct lm_info
SVR4 systems will fall back to using a symbol as the "startup
mapping complete" breakpoint address. */

-#ifdef SVR4_SHARED_LIBS
static char *solib_break_names[] =
{
"r_debug_state",
@@ -103,11 +82,10 @@ static char *solib_break_names[] =
"_rtld_debug_state",
NULL
};
-#endif

#define BKPT_AT_SYMBOL 1

-#if defined (BKPT_AT_SYMBOL) && defined (SVR4_SHARED_LIBS)
+#if defined (BKPT_AT_SYMBOL)
static char *bkpt_names[] =
{
#ifdef SOLIB_BKPT_NAME
@@ -119,24 +97,12 @@ static char *bkpt_names[] =
};
#endif

-/* Symbols which are used to locate the base of the link map structures. */
-
-#ifndef SVR4_SHARED_LIBS
-static char *debug_base_symbols[] =
-{
- "_DYNAMIC",
- "_DYNAMIC__MGC",
- NULL
-};
-#endif
-
static char *main_name_list[] =
{
"main_$main",
NULL
};

-
/* Macro to extract an address from a solib structure.
When GDB is configured for some 32-bit targets (e.g. Solaris 2.7
sparc), BFD is configured to handle 64-bit targets, so CORE_ADDR is
@@ -148,20 +114,6 @@ static char *main_name_list[] =

/* local data declarations */

-#ifndef SVR4_SHARED_LIBS
-
-/* NOTE: converted the macros LM_ADDR, LM_NEXT, LM_NAME and
- IGNORE_FIRST_LINK_MAP_ENTRY into functions (see below).
- MVS, June 2000 */
-
-static struct link_dynamic dynamic_copy;
-static struct link_dynamic_2 ld_2_copy;
-static struct ld_debug debug_copy;
-static CORE_ADDR debug_addr;
-static CORE_ADDR flag_addr;
-
-#endif /* !SVR4_SHARED_LIBS */
-
/* link map access functions */

static CORE_ADDR
@@ -189,16 +141,6 @@ LM_NAME (struct so_list *so)
return extract_address (so->lm_info->lm + lmo->l_name_offset, lmo->l_name_size);
}

-#ifndef SVR4_SHARED_LIBS
-
-static int
-IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so)
-{
- return 0;
-}
-
-#else /* SVR4_SHARED_LIBS */
-
static int
IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so)
{
@@ -208,8 +150,6 @@ IGNORE_FIRST_LINK_MAP_ENTRY (struct so_l
lmo->l_prev_size) == 0;
}

-#endif /* !SVR4_SHARED_LIBS */
-
static CORE_ADDR debug_base; /* Base of dynamic linker structures */
static CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */

@@ -217,112 +157,6 @@ static CORE_ADDR breakpoint_addr; /* Add

static int match_main (char *);

-#ifndef SVR4_SHARED_LIBS
-
-/* Allocate the runtime common object file. */
-
-static void
-allocate_rt_common_objfile (void)
-{
- struct objfile *objfile;
- struct objfile *last_one;
-
- objfile = (struct objfile *) xmalloc (sizeof (struct objfile));
- memset (objfile, 0, sizeof (struct objfile));
- objfile->md = NULL;
- obstack_specify_allocation (&objfile->psymbol_cache.cache, 0, 0,
- xmalloc, xfree);
- obstack_specify_allocation (&objfile->psymbol_obstack, 0, 0, xmalloc,
- xfree);
- obstack_specify_allocation (&objfile->symbol_obstack, 0, 0, xmalloc,
- xfree);
- obstack_specify_allocation (&objfile->type_obstack, 0, 0, xmalloc,
- xfree);
- objfile->name = mstrsave (objfile->md, "rt_common");
-
- /* Add this file onto the tail of the linked list of other such files. */
-
- objfile->next = NULL;
- if (object_files == NULL)
- object_files = objfile;
- else
- {
- for (last_one = object_files;
- last_one->next;
- last_one = last_one->next);
- last_one->next = objfile;
- }
-
- rt_common_objfile = objfile;
-}
-
-/* Read all dynamically loaded common symbol definitions from the inferior
- and put them into the minimal symbol table for the runtime common
- objfile. */
-
-static void
-solib_add_common_symbols (CORE_ADDR rtc_symp)
-{
- struct rtc_symb inferior_rtc_symb;
- struct nlist inferior_rtc_nlist;
- int len;
- char *name;
-
- /* Remove any runtime common symbols from previous runs. */
-
- if (rt_common_objfile != NULL && rt_common_objfile->minimal_symbol_count)
- {
- obstack_free (&rt_common_objfile->symbol_obstack, 0);
- obstack_specify_allocation (&rt_common_objfile->symbol_obstack, 0, 0,
- xmalloc, xfree);
- rt_common_objfile->minimal_symbol_count = 0;
- rt_common_objfile->msymbols = NULL;
- }
-
- init_minimal_symbol_collection ();
- make_cleanup_discard_minimal_symbols ();
-
- while (rtc_symp)
- {
- read_memory (rtc_symp,
- (char *) &inferior_rtc_symb,
- sizeof (inferior_rtc_symb));
- read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb.rtc_sp),
- (char *) &inferior_rtc_nlist,
- sizeof (inferior_rtc_nlist));
- if (inferior_rtc_nlist.n_type == N_COMM)
- {
- /* FIXME: The length of the symbol name is not available, but in the
- current implementation the common symbol is allocated immediately
- behind the name of the symbol. */
- len = inferior_rtc_nlist.n_value - inferior_rtc_nlist.n_un.n_strx;
-
- name = xmalloc (len);
- read_memory (SOLIB_EXTRACT_ADDRESS (inferior_rtc_nlist.n_un.n_name),
- name, len);
-
- /* Allocate the runtime common objfile if necessary. */
- if (rt_common_objfile == NULL)
- allocate_rt_common_objfile ();
-
- prim_record_minimal_symbol (name, inferior_rtc_nlist.n_value,
- mst_bss, rt_common_objfile);
- xfree (name);
- }
- rtc_symp = SOLIB_EXTRACT_ADDRESS (inferior_rtc_symb.rtc_next);
- }
-
- /* Install any minimal symbols that have been collected as the current
- minimal symbols for the runtime common objfile. */
-
- install_minimal_symbols (rt_common_objfile);
-}
-
-#endif /* SVR4_SHARED_LIBS */
-
-
-#ifdef SVR4_SHARED_LIBS
-
static CORE_ADDR bfd_lookup_symbol (bfd *, char *);

/*
@@ -649,8 +483,6 @@ elf_locate_base (void)
return 0;
}

-#endif /* SVR4_SHARED_LIBS */
-
/*

LOCAL FUNCTION
@@ -691,30 +523,6 @@ elf_locate_base (void)
static CORE_ADDR
locate_base (void)
{
-
-#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
@@ -732,9 +540,6 @@ locate_base (void)
#endif
}
return (debug_base);
-
-#endif /* !SVR4_SHARED_LIBS */
-
}

/*
@@ -758,20 +563,6 @@ static CORE_ADDR
first_link_map_member (void)
{
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 */
struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
char *r_map_buf = xmalloc (lmo->r_map_size);
struct cleanup *cleanups = make_cleanup (xfree, r_map_buf);
@@ -786,12 +577,9 @@ first_link_map_member (void)

do_cleanups (cleanups);

-#endif /* !SVR4_SHARED_LIBS */
-
return (lm);
}

-#ifdef SVR4_SHARED_LIBS
/*

LOCAL FUNCTION
@@ -864,17 +652,7 @@ open_symbol_file_object (void *from_ttyp

return 1;
}
-#else
-
-static int
-open_symbol_file_object (void *from_ttyp)
-{
- return 1;
-}
-
-#endif /* SVR4_SHARED_LIBS */

-
/* LOCAL FUNCTION

current_sos -- build a list of currently loaded shared objects
@@ -1002,10 +780,8 @@ match_main (char *soname)
return (0);
}

-
/* Return 1 if PC lies in the dynamic symbol resolution code of the
SVR4 run time loader. */
-#ifdef SVR4_SHARED_LIBS
static CORE_ADDR interp_text_sect_low;
static CORE_ADDR interp_text_sect_high;
static CORE_ADDR interp_plt_sect_low;
@@ -1018,68 +794,7 @@ svr4_in_dynsym_resolve_code (CORE_ADDR p
|| (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
|| in_plt_section (pc, NULL));
}
-#else /* !SVR4_SHARED_LIBS */
-static int
-svr4_in_dynsym_resolve_code (CORE_ADDR pc)
-{
- return 0;
-}
-#endif /* SVR4_SHARED_LIBS */
-
-/*
-
- 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 (void)
-{
- int status = 1;
-
- 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));
-
- /* 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 */

/*

@@ -1129,38 +844,6 @@ enable_break (void)
{
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;
@@ -1171,7 +854,6 @@ enable_break (void)
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;

@@ -1287,7 +969,6 @@ enable_break (void)
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. */
@@ -1308,8 +989,6 @@ enable_break (void)

#endif /* BKPT_AT_SYMBOL */

-#endif /* !SVR4_SHARED_LIBS */
-
return (success);
}

@@ -1329,54 +1008,18 @@ enable_break (void)
way, we are called to do any system specific symbol handling that
is needed.

- For SunOS4, this consists of grunging around in the dynamic
+ For SunOS4, this consisted 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.

+ However, for SVR4, there's nothing to do.
+
*/

static void
svr4_special_symbol_handling (void)
{
-#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 */
}

/* Relocate the main executable. This function should be called upon
@@ -1543,26 +1186,14 @@ svr4_solib_create_inferior_hook (void)
/* Relocate the main executable if necessary. */
svr4_relocate_main_executable ();

- /* 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
+#if defined(_SCO_DS)
+ /* SCO needs the loop below, other systems should be using the
special shared library breakpoints and the shared library breakpoint
service routine.

@@ -1581,28 +1212,7 @@ svr4_solib_create_inferior_hook (void)
}
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
+#endif /* defined(_SCO_DS) */
}

static void
Index: config/i386/nbsd.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/nbsd.mh,v
retrieving revision 1.9
diff -u -p -r1.9 nbsd.mh
--- nbsd.mh 2001/03/19 05:15:32 1.9
+++ nbsd.mh 2001/09/29 18:15:40
@@ -7,7 +7,7 @@ XDEPFILES=
# continuation character (backslash) to extend a commented line. As a
# consequence, BSD make considers subsequent tab-indented lines to be
# "unassociated shell commands".
-NATDEPFILES= fork-child.o infptrace.o inftarg.o corelow.o i386nbsd-nat.o solib.o solib-svr4.o solib-legacy.o
+NATDEPFILES= fork-child.o infptrace.o inftarg.o corelow.o i386nbsd-nat.o solib.o solib-sunos.o

XM_FILE= xm-nbsd.h
NAT_FILE= nm-nbsd.h
Index: config/i386/sun386.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/sun386.mt,v
retrieving revision 1.4
diff -u -p -r1.4 sun386.mt
--- sun386.mt 2001/04/11 22:39:07 1.4
+++ sun386.mt 2001/09/29 18:15:40
@@ -1,3 +1,3 @@
# OBSOLETE # Target: Sun 386i target configuration file.
-# OBSOLETE TDEPFILES= i386-tdep.o solib.o solib-svr4.o solib-legacy.o
+# OBSOLETE TDEPFILES= i386-tdep.o solib.o solib-sunos.o
# OBSOLETE TM_FILE= tm-sun386.h
Index: config/m68k/nbsd.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/m68k/nbsd.mh,v
retrieving revision 1.7
diff -u -p -r1.7 nbsd.mh
--- nbsd.mh 2001/03/10 06:17:22 1.7
+++ nbsd.mh 2001/09/29 18:15:40
@@ -1,5 +1,5 @@
# Host: Motorola m68k running NetBSD
XDEPFILES=
-NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o m68knbsd-nat.o solib.o solib-svr4.o solib-legacy.o
+NATDEPFILES= infptrace.o inftarg.o fork-child.o corelow.o m68knbsd-nat.o solib.o solib-sunos.o
XM_FILE= xm-nbsd.h
NAT_FILE= nm-nbsd.h
Index: config/m68k/sun2os4.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/m68k/sun2os4.mt,v
retrieving revision 1.3
diff -u -p -r1.3 sun2os4.mt
--- sun2os4.mt 2001/03/10 06:17:22 1.3
+++ sun2os4.mt 2001/09/29 18:15:40
@@ -1,3 +1,3 @@
# Target: Sun 2, running SunOS 4
-TDEPFILES= solib.o solib-svr4.o solib-legacy.o m68k-tdep.o
+TDEPFILES= solib.o solib-sunos.o m68k-tdep.o
TM_FILE= tm-sun2os4.h
Index: config/m68k/sun3os4.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/m68k/sun3os4.mt,v
retrieving revision 1.3
diff -u -p -r1.3 sun3os4.mt
--- sun3os4.mt 2001/03/10 06:17:22 1.3
+++ sun3os4.mt 2001/09/29 18:15:40
@@ -1,3 +1,3 @@
# Target: Sun 3, running SunOS 4, as a target system
-TDEPFILES= solib.o solib-svr4.o solib-legacy.o m68k-tdep.o
+TDEPFILES= solib.o solib-sunos.o m68k-tdep.o
TM_FILE= tm-sun3os4.h
Index: config/ns32k/nbsd.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/ns32k/nbsd.mh,v
retrieving revision 1.7
diff -u -p -r1.7 nbsd.mh
--- nbsd.mh 2001/03/10 06:17:23 1.7
+++ nbsd.mh 2001/09/29 18:15:40
@@ -1,5 +1,5 @@
# Host: PC532 running NetBSD
XDEPFILES=
-NATDEPFILES= fork-child.o infptrace.o inftarg.o corelow.o ns32knbsd-nat.o solib.o solib-svr4.o solib-legacy.o
+NATDEPFILES= fork-child.o infptrace.o inftarg.o corelow.o ns32knbsd-nat.o solib.o solib-sunos.o
XM_FILE= xm-nbsd.h
NAT_FILE= nm-nbsd.h
Index: config/sparc/nbsd.mh
===================================================================
RCS file: /cvs/src/src/gdb/config/sparc/nbsd.mh,v
retrieving revision 1.6
diff -u -p -r1.6 nbsd.mh
--- nbsd.mh 2001/03/10 06:17:24 1.6
+++ nbsd.mh 2001/09/29 18:15:41
@@ -1,6 +1,6 @@
# Host: Sun 4 or Sparcstation, running NetBSD
XDEPFILES=
-NATDEPFILES= fork-child.o infptrace.o inftarg.o corelow.o sparc-nat.o solib.o solib-svr4.o solib-legacy.o
+NATDEPFILES= fork-child.o infptrace.o inftarg.o corelow.o sparc-nat.o solib.o solib-sunos.o
XM_FILE= xm-nbsd.h
NAT_FILE= nm-nbsd.h
HOST_IPC=-DBSD_IPC
Index: config/sparc/sun4os4.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/sparc/sun4os4.mt,v
retrieving revision 1.3
diff -u -p -r1.3 sun4os4.mt
--- sun4os4.mt 2001/03/10 06:17:24 1.3
+++ sun4os4.mt 2001/09/29 18:15:41
@@ -1,3 +1,3 @@
# Target: Sun 4 or Sparcstation, running SunOS 4
-TDEPFILES= sparc-tdep.o solib.o solib-svr4.o solib-legacy.o
+TDEPFILES= sparc-tdep.o solib.o solib-sunos.o
TM_FILE= tm-sun4os4.h