[PATCH v10 1/5] New remove-symbol-file command.

Nicolas Blanc
2013-06-24T08:36:50Z

New command for removing symbol files added via
the add-symbol-file command.

2013-18-03 Nicolas Blanc <nicolas.blanc@intel.com>

* breakpoint.c (disable_breakpoints_in_freed_objfile): New function.
* objfiles.c (free_objfile): Notify free_objfile.
(is_addr_in_objfile): New function.
* objfiles.h (is_addr_in_objfile): New declaration.
* printcmd.c (clear_dangling_display_expressions): Act upon free_objfile
events instead of solib_unloaded events.
(_initialize_printcmd): Register observer for free_objfile instead
of solib_unloaded notifications.
* solib.c (remove_user_added_objfile): New function.
* symfile.c (remove_symbol_file_command): New command.
(_initialize_symfile): Add remove-symbol-file.
gdb/doc
* observer.texi: New free_objfile event.

Signed-off-by: Nicolas Blanc <nicolas.blanc@intel.com>
---
gdb/breakpoint.c | 67 ++++++++++++++++++++++++++++++++++++++--
gdb/doc/observer.texi | 4 ++
gdb/objfiles.c | 23 ++++++++++++++
gdb/objfiles.h | 2 +
gdb/printcmd.c | 15 +++++---
gdb/solib.c | 22 +++++++++++++
gdb/symfile.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 206 insertions(+), 9 deletions(-)

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 0ff5a4e..94acbf4 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -7412,9 +7412,9 @@ disable_breakpoints_in_shlibs (void)
}
}

-/* Disable any breakpoints and tracepoints that are in an unloaded shared
- library. Only apply to enabled breakpoints, disabled ones can just stay
- disabled. */
+/* Disable any breakpoints and tracepoints that are in SOLIB upon
+ notification of unloaded_shlib. Only apply to enabled breakpoints,
+ disabled ones can just stay disabled. */

static void
disable_breakpoints_in_unloaded_shlib (struct so_list *solib)
@@ -7466,6 +7466,66 @@ disable_breakpoints_in_unloaded_shlib (struct so_list *solib)
}
}

+/* Disable any breakpoints and tracepoints in OBJFILE upon
+ notification of free_objfile. Only apply to enabled breakpoints,
+ disabled ones can just stay disabled. */
+
+static void
+disable_breakpoints_in_freed_objfile (struct objfile *objfile)
+{
+ struct breakpoint *b;
+
+ if (objfile == NULL)
+ return;
+
+ /* If the file is a shared library not loaded by the user then
+ solib_unloaded was notified and disable_breakpoints_in_unloaded_shlib
+ was called. In that case there is no need to take action again. */
+ if ((objfile->flags & OBJF_SHARED) && !(objfile->flags & OBJF_USERLOADED))
+ return;
+
+ ALL_BREAKPOINTS (b)
+ {
+ struct bp_location *loc;
+ int bp_modified = 0;
+
+ if (!is_breakpoint (b) && !is_tracepoint (b))
+ continue;
+
+ for (loc = b->loc; loc != NULL; loc = loc->next)
+ {
+ CORE_ADDR loc_addr = loc->address;
+
+ if (loc->loc_type != bp_loc_hardware_breakpoint
+ && loc->loc_type != bp_loc_software_breakpoint)
+ continue;
+
+ if (loc->shlib_disabled != 0)
+ continue;
+
+ if (objfile->pspace != loc->pspace)
+ continue;
+
+ if (loc->loc_type != bp_loc_hardware_breakpoint
+ && loc->loc_type != bp_loc_software_breakpoint)
+ continue;
+
+ if (is_addr_in_objfile (loc_addr, objfile))
+ {
+ loc->shlib_disabled = 1;
+ loc->inserted = 0;
+
+ mark_breakpoint_location_modified (loc);
+
+ bp_modified = 1;
+ }
+ }
+
+ if (bp_modified)
+ observer_notify_breakpoint_modified (b);
+ }
+}
+
/* FORK & VFORK catchpoints. */

/* An instance of this type is used to represent a fork or vfork
@@ -15884,6 +15944,7 @@ _initialize_breakpoint (void)
initialize_breakpoint_ops ();

observer_attach_solib_unloaded (disable_breakpoints_in_unloaded_shlib);
+ observer_attach_free_objfile (disable_breakpoints_in_freed_objfile);
observer_attach_inferior_exit (clear_syscall_counts);
observer_attach_memory_changed (invalidate_bp_value_on_memory_change);

diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index adb7085..f753965 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -138,6 +138,10 @@ Called with @var{objfile} equal to @code{NULL} to indicate
previously loaded symbol table data has now been invalidated.
@end deftypefun

+@deftypefun void free_objfile (struct objfile *@var{objfile})
+The object file specified by @var{objfile} is about to be freed.
+@end deftypefun
+
@deftypefun void new_thread (struct thread_info *@var{t})
The thread specified by @var{t} has been created.
@end deftypefun
diff --git a/gdb/objfiles.c b/gdb/objfiles.c
index 1e1b7bc..8fed7e8 100644
--- a/gdb/objfiles.c
+++ b/gdb/objfiles.c
@@ -539,6 +539,9 @@ free_objfile_separate_debug (struct objfile *objfile)
void
free_objfile (struct objfile *objfile)
{
+ /* First notify observers that this objfile is about to be freed. */
+ observer_notify_free_objfile (objfile);
+
/* Free all separate debug objfiles. */
free_objfile_separate_debug (objfile);

@@ -1463,6 +1466,26 @@ resume_section_map_updates_cleanup (void *arg)
resume_section_map_updates (arg);
}

+/* Return 1 if ADDR maps into one of the sections of OBJFILE and 0
+ otherwise. */
+
+int
+is_addr_in_objfile (CORE_ADDR addr, const struct objfile *objfile)
+{
+ struct obj_section *osect;
+
+ if (objfile == NULL)
+ return 0;
+
+ ALL_OBJFILE_OSECTIONS (objfile, osect)
+ {
+ if (obj_section_addr (osect) <= addr
+ && addr < obj_section_endaddr (osect))
+ return 1;
+ }
+ return 0;
+}
+
/* The default implementation for the "iterate_over_objfiles_in_search_order"
gdbarch method. It is equivalent to use the ALL_OBJFILES macro,
searching the objfiles in the order they are stored internally,
diff --git a/gdb/objfiles.h b/gdb/objfiles.h
index adb1ef8..b92b592 100644
--- a/gdb/objfiles.h
+++ b/gdb/objfiles.h
@@ -482,6 +482,8 @@ extern int have_full_symbols (void);

extern void objfiles_changed (void);

+extern int is_addr_in_objfile (CORE_ADDR addr, const struct objfile *objfile);
+
/* This operation deletes all objfile entries that represent solibs that
weren't explicitly loaded by the user, via e.g., the add-symbol-file
command. */
diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index 99d4dba..1234135 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -1936,21 +1936,24 @@ disable_display_command (char *args, int from_tty)
an item by re-parsing .exp_string field in the new execution context. */

static void
-clear_dangling_display_expressions (struct so_list *solib)
+clear_dangling_display_expressions (struct objfile *objfile)
{
- struct objfile *objfile = solib->objfile;
struct display *d;
+ struct program_space *pspace;

/* With no symbol file we cannot have a block or expression from it. */
if (objfile == NULL)
return;
+ pspace = objfile->pspace;
if (objfile->separate_debug_objfile_backlink)
- objfile = objfile->separate_debug_objfile_backlink;
- gdb_assert (objfile->pspace == solib->pspace);
+ {
+ objfile = objfile->separate_debug_objfile_backlink;
+ gdb_assert (objfile->pspace == pspace);
+ }

for (d = display_chain; d != NULL; d = d->next)
{
- if (d->pspace != solib->pspace)
+ if (d->pspace != pspace)
continue;

if (lookup_objfile_from_block (d->block) == objfile
@@ -2482,7 +2485,7 @@ _initialize_printcmd (void)

current_display_number = -1;

- observer_attach_solib_unloaded (clear_dangling_display_expressions);
+ observer_attach_free_objfile (clear_dangling_display_expressions);

add_info ("address", address_info,
_("Describe where symbol SYM is stored."));
diff --git a/gdb/solib.c b/gdb/solib.c
index c987fe5..f21ba21 100644
--- a/gdb/solib.c
+++ b/gdb/solib.c
@@ -1478,6 +1478,26 @@ gdb_bfd_lookup_symbol (bfd *abfd,
return symaddr;
}

+/* SO_LIST_HEAD may contain user-loaded object files that can be removed
+ out-of-band by the user. So upon notification of free_objfile remove
+ all references to any user-loaded file that is about to be freed. */
+
+static void
+remove_user_added_objfile (struct objfile *objfile)
+{
+ struct so_list *so;
+
+ if (objfile == NULL)
+ return;
+
+ if (objfile->flags & OBJF_USERLOADED)
+ {
+ for (so = so_list_head; so != NULL; so = so->next)
+ if (so->objfile == objfile)
+ so->objfile = NULL;
+ }
+}
+
extern initialize_file_ftype _initialize_solib; /* -Wmissing-prototypes */

void
@@ -1485,6 +1505,8 @@ _initialize_solib (void)
{
solib_data = gdbarch_data_register_pre_init (solib_init);

+ observer_attach_free_objfile (remove_user_added_objfile);
+
add_com ("sharedlibrary", class_files, sharedlibrary_command,
_("Load shared object library symbols for files matching REGEXP."));
add_info ("sharedlibrary", info_sharedlibrary_command,
diff --git a/gdb/symfile.c b/gdb/symfile.c
index c22f19b..e522612 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -2326,6 +2326,79 @@ add_symbol_file_command (char *args, int from_tty)
}
\f

+/* This function removes a symbol file that was added via add-symbol-file. */
+
+static void
+remove_symbol_file_command (char *args, int from_tty)
+{
+ char **argv;
+ struct objfile *objf = NULL;
+ struct cleanup *my_cleanups;
+ struct program_space *pspace = current_program_space;
+ struct gdbarch *gdbarch = get_current_arch ();
+
+ dont_repeat ();
+
+ if (args == NULL)
+ error (_("remove-symbol-file FILENAME\nremove-symbol-file -a ADDRESS"));
+
+ my_cleanups = make_cleanup (null_cleanup, NULL);
+
+ argv = gdb_buildargv (args);
+
+ if (strcmp (argv[0], "-a") == 0)
+ {
+ /* Interpret the next argument as an address. */
+ CORE_ADDR addr;
+
+ if (argv[1] == NULL)
+ error (_("Missing address argument"));
+
+ if (argv[2] != NULL)
+ error (_("Junk after %s"), argv[1]);
+
+ addr = parse_and_eval_address (argv[1]);
+
+ ALL_OBJFILES (objf)
+ {
+ if (objf->flags & OBJF_USERLOADED
+ && objf->pspace == pspace && is_addr_in_objfile (addr, objf))
+ break;
+ }
+ }
+ else if (argv[0] != NULL)
+ {
+ /* Interpret the current argument as a file name. */
+ char *filename;
+
+ if (argv[1] != NULL)
+ error (_("Junk after %s"), argv[0]);
+
+ filename = tilde_expand (argv[0]);
+ make_cleanup (xfree, filename);
+
+ ALL_OBJFILES (objf)
+ {
+ if (objf->flags & OBJF_USERLOADED
+ && objf->pspace == pspace
+ && filename_cmp (filename, objf->name) == 0)
+ break;
+ }
+ }
+
+ if (objf == NULL)
+ error (_("No symbol file found"));
+
+ if (from_tty
+ && !query (_("Remove symbol table from file \"%s\"? "), objf->name))
+ error (_("Not confirmed."));
+
+ free_objfile (objf);
+ clear_symtab_users (0);
+
+ do_cleanups (my_cleanups);
+}
+
typedef struct objfile *objfilep;

DEF_VEC_P (objfilep);
@@ -3740,6 +3813,15 @@ with the text. SECT is a section name to be loaded at SECT_ADDR."),
&cmdlist);
set_cmd_completer (c, filename_completer);

+ c = add_cmd ("remove-symbol-file", class_files,
+ remove_symbol_file_command, _("\
+Remove a symbol file added via the add-symbol-file command.\n\
+Usage: remove-symbol-file FILENAME\n\
+ remove-symbol-file -a ADDRESS\n\
+The file to remove can be identified by its filename or by an address\n\
+that lies within the boundaries of this symbol file in memory."),
+ &cmdlist);
+
c = add_cmd ("load", class_files, load_command, _("\
Dynamically load FILE into the running program, and record its symbols\n\
for access from GDB.\n\
--
1.7.1