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* GDB aborts on missing command args. Which way to fix?
@ 2008-09-16 17:50 Paul Pluzhnikov
  2008-09-19 21:52 ` Tom Tromey
  0 siblings, 1 reply; 6+ messages in thread
From: Paul Pluzhnikov @ 2008-09-16 17:50 UTC (permalink / raw)
  To: gdb-patches

Greetings,

There are many instances of calls to buildargv() which aren't
protected by 'if (args != NULL)', and cause gdb to abort.

For example:

(gdb) remote del        # missing argument to del.

Program received signal SIGABRT, Aborted.
0x00002aaaab5cac75 in *__GI_raise (sig=<value optimized out>) at
../nptl/sysdeps/unix/sysv/linux/raise.c:64
64        return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
(gdb-top) bt
#0  0x00002aaaab5cac75 in *__GI_raise (sig=<value optimized out>) at
../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00002aaaab5cc620 in *__GI_abort () at ../sysdeps/generic/abort.c:88
#2  0x000000000044f1a5 in internal_vproblem (problem=0x9ad3c0,
file=0x6454db "../../src/gdb/utils.c", line=1002, fmt=<value optimized
out>, ap=<value optimized out>) at ../../src/gdb/utils.c:874
#3  0x000000000044c3c9 in internal_verror (file=0x32a <Address 0x32a
out of bounds>, line=6, fmt=0xffffffffffffffff <Address
0xffffffffffffffff out of bounds>, ap=0x0) at
../../src/gdb/utils.c:889
#4  0x000000000044c461 in internal_error (file=0x32a <Address 0x32a
out of bounds>, line=810, string=0x6 <Address 0x6 out of bounds>) at
../../src/gdb/utils.c:898
#5  0x000000000044cf66 in nomem (size=0) at ../../src/gdb/utils.c:1002
#6  0x0000000000472db1 in remote_delete_command (args=<value optimized
out>, from_tty=0) at ../../src/gdb/remote.c:7231
#7  0x000000000044b323 in execute_command (p=0x9d91ca "", from_tty=0)
at ../../src/gdb/top.c:457
#8  0x00000000004e9617 in command_handler (command=0x9d91c0 "remote
del") at ../../src/gdb/event-top.c:514
#9  0x00000000004ea190 in command_line_handler (rl=<value optimized
out>) at ../../src/gdb/event-top.c:739
#10 0x0000000000597303 in rl_callback_read_char () at
../../src/readline/callback.c:205
#11 0x00000000004e9749 in rl_callback_read_char_wrapper
(client_data=0x32a) at ../../src/gdb/event-top.c:178
#12 0x00000000004e83a3 in process_event () at ../../src/gdb/event-loop.c:341
#13 0x00000000004e8cb8 in gdb_do_one_event (data=<value optimized
out>) at ../../src/gdb/event-loop.c:378
#14 0x00000000004e54db in catch_errors (func=0x4e8b00
<gdb_do_one_event>, func_args=0x0, errstring=0x64d064 "", mask=<value
optimized out>) at ../../src/gdb/exceptions.c:516
#15 0x0000000000490276 in tui_command_loop (data=<value optimized
out>) at ../../src/gdb/tui/tui-interp.c:153
#16 0x0000000000444139 in captured_command_loop (data=0x32a) at
../../src/gdb/main.c:99
#17 0x00000000004e54db in catch_errors (func=0x444130
<captured_command_loop>, func_args=0x0, errstring=0x64d064 "",
mask=<value optimized out>) at ../../src/gdb/exceptions.c:516
#18 0x00000000004448de in captured_main (data=<value optimized out>)
at ../../src/gdb/main.c:831
#19 0x00000000004e54db in catch_errors (func=0x444170 <captured_main>,
func_args=0x7fffffffe620, errstring=0x64d064 "", mask=<value optimized
out>) at ../../src/gdb/exceptions.c:516
#20 0x0000000000444124 in gdb_main (args=0x32a) at ../../src/gdb/main.c:840
#21 0x00000000004440f6 in main (argc=<value optimized out>,
argv=0x32a) at ../../src/gdb/gdb.c:33


I can fix this by adding the 'if (args != NULL)' checks everywhere,
or by switching to 'buildargv_not_null(args, "appropriate missing
argument error")'

Which way is preferred? (I prefer the second way).

Thanks,
-- 
Paul Pluzhnikov


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: GDB aborts on missing command args. Which way to fix?
  2008-09-16 17:50 GDB aborts on missing command args. Which way to fix? Paul Pluzhnikov
@ 2008-09-19 21:52 ` Tom Tromey
  2008-09-19 22:02   ` Daniel Jacobowitz
  0 siblings, 1 reply; 6+ messages in thread
From: Tom Tromey @ 2008-09-19 21:52 UTC (permalink / raw)
  To: Paul Pluzhnikov; +Cc: gdb-patches

>>>>> "Paul" == Paul Pluzhnikov <ppluzhnikov@google.com> writes:

Paul> There are many instances of calls to buildargv() which aren't
Paul> protected by 'if (args != NULL)', and cause gdb to abort.
[...]
Paul> I can fix this by adding the 'if (args != NULL)' checks everywhere,
Paul> or by switching to 'buildargv_not_null(args, "appropriate missing
Paul> argument error")'

Paul> Which way is preferred? (I prefer the second way).

That seems reasonable to me.

I think you might as well make it call nomem if the result is NULL,
too.

Tom


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: GDB aborts on missing command args. Which way to fix?
  2008-09-19 21:52 ` Tom Tromey
@ 2008-09-19 22:02   ` Daniel Jacobowitz
  2008-09-26 23:22     ` [patch] " Paul Pluzhnikov
  0 siblings, 1 reply; 6+ messages in thread
From: Daniel Jacobowitz @ 2008-09-19 22:02 UTC (permalink / raw)
  To: Tom Tromey; +Cc: Paul Pluzhnikov, gdb-patches

On Fri, Sep 19, 2008 at 03:50:03PM -0600, Tom Tromey wrote:
> >>>>> "Paul" == Paul Pluzhnikov <ppluzhnikov@google.com> writes:
> 
> Paul> There are many instances of calls to buildargv() which aren't
> Paul> protected by 'if (args != NULL)', and cause gdb to abort.
> [...]
> Paul> I can fix this by adding the 'if (args != NULL)' checks everywhere,
> Paul> or by switching to 'buildargv_not_null(args, "appropriate missing
> Paul> argument error")'
> 
> Paul> Which way is preferred? (I prefer the second way).
> 
> That seems reasonable to me.
> 
> I think you might as well make it call nomem if the result is NULL,
> too.

I don't like passing error messages to functions that might fail; I
find it very confusing.  If you want to give usage errors, why not
combine it with the existing checks for wrong arguments?

Tom's got a good point about nomem, though.

-- 
Daniel Jacobowitz
CodeSourcery


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [patch] Re: GDB aborts on missing command args. Which way to fix?
  2008-09-19 22:02   ` Daniel Jacobowitz
@ 2008-09-26 23:22     ` Paul Pluzhnikov
  2008-10-03  7:04       ` Joel Brobecker
  0 siblings, 1 reply; 6+ messages in thread
From: Paul Pluzhnikov @ 2008-09-26 23:22 UTC (permalink / raw)
  To: Tom Tromey, gdb-patches

On Fri, Sep 19, 2008 at 3:01 PM, Daniel Jacobowitz <drow@false.org> wrote:

> I don't like passing error messages to functions that might fail; I
...
> Tom's got a good point about nomem, though.

Ok.

Tested on Linux/x86_64, no regressions.


-- 
Paul Pluzhnikov

2008-09-26  Paul Pluzhnikov  <ppluzhnikov@google.com>

	* utils.c, defs.h (gdb_buildargv): New fn. Wrap buildargv
	and check for out-of-memory condition.
	* exec.c (exec_file_command): Call it.
	* infrun.c (handle_command, xdb_handle_command): Likewise.
	* interps.c (interpreter_exec_cmd): Likewise.
	* linux-nat.c (linux_nat_info_proc_cmd): Likewise.
	* procfs.c (info_proc_cmd): Likewise.
	* remote-mips.c (common_open): Likewise.
	* remote-sim.c (gdbsim_kill, gdbsim_create_inferior,
	gdbsim_open): Likewise.
	* remote.c (extended_remote_run, remote_put_command,
	remote_get_command, remote_delete_command): Likewise.
	* ser-mingw.c (pipe_windows_open): Likesise.
	* source.c (add_path, show_substitute_path_command,
	unset_substitute_path_command, set_substitute_path_command):
	Likewise.
	* stack.c (backtrace_command): Likewise.
	* symfile.c (symbol_file_command, generic_load,
	add_symbol_file_command): Likesise.
	* symmisc.c (maintenance_print_symbols, maintenance_print_psymbols,
	maintenance_print_msymbols): Likewise.


Index: defs.h
===================================================================
RCS file: /cvs/src/src/gdb/defs.h,v
retrieving revision 1.237
diff -u -d -p -u -r1.237 defs.h
--- defs.h	14 Sep 2008 06:37:18 -0000	1.237
+++ defs.h	26 Sep 2008 22:45:22 -0000
@@ -405,6 +405,8 @@ ULONGEST strtoulst (const char *num, con

 char *ldirname (const char *filename);

+char **gdb_buildargv (const char *);
+
 /* From demangle.c */

 extern void set_demangling_style (char *);
Index: exec.c
===================================================================
RCS file: /cvs/src/src/gdb/exec.c,v
retrieving revision 1.77
diff -u -d -p -u -r1.77 exec.c
--- exec.c	5 Sep 2008 11:37:17 -0000	1.77
+++ exec.c	26 Sep 2008 22:45:22 -0000
@@ -302,10 +302,7 @@ exec_file_command (char *args, int from_
       /* Scan through the args and pick up the first non option arg
          as the filename.  */

-      argv = buildargv (args);
-      if (argv == NULL)
-        nomem (0);
-
+      argv = gdb_buildargv (args);
       make_cleanup_freeargv (argv);

       for (; (*argv != NULL) && (**argv == '-'); argv++)
Index: infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.322
diff -u -d -p -u -r1.322 infrun.c
--- infrun.c	22 Sep 2008 15:26:53 -0000	1.322
+++ infrun.c	26 Sep 2008 22:45:22 -0000
@@ -4070,11 +4070,7 @@ handle_command (char *args, int from_tty

   /* Break the command line up into args. */

-  argv = buildargv (args);
-  if (argv == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   old_chain = make_cleanup_freeargv (argv);

   /* Walk through the args, looking for signal oursigs, signal names, and
@@ -4231,13 +4227,12 @@ xdb_handle_command (char *args, int from
   char **argv;
   struct cleanup *old_chain;

+  if (args == NULL)
+    error_no_arg (_("xdb command"));
+
   /* Break the command line up into args. */

-  argv = buildargv (args);
-  if (argv == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   old_chain = make_cleanup_freeargv (argv);
   if (argv[1] != (char *) NULL)
     {
Index: interps.c
===================================================================
RCS file: /cvs/src/src/gdb/interps.c,v
retrieving revision 1.28
diff -u -d -p -u -r1.28 interps.c
--- interps.c	28 Jul 2008 17:53:52 -0000	1.28
+++ interps.c	26 Sep 2008 22:45:22 -0000
@@ -371,11 +371,11 @@ interpreter_exec_cmd (char *args, int fr
   unsigned int i;
   int old_quiet, use_quiet;

-  prules = buildargv (args);
+  prules = gdb_buildargv (args);
   if (prules == NULL)
-    {
-      error (_("unable to parse arguments"));
-    }
+    error (_("unable to parse arguments"));
+  else
+    make_cleanup_freeargv (prules);

   nrules = 0;
   if (prules != NULL)
Index: linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/linux-nat.c,v
retrieving revision 1.106
diff -u -d -p -u -r1.106 linux-nat.c
--- linux-nat.c	25 Sep 2008 14:13:44 -0000	1.106
+++ linux-nat.c	26 Sep 2008 22:45:22 -0000
@@ -3591,10 +3591,8 @@ linux_nat_info_proc_cmd (char *args, int
   if (args)
     {
       /* Break up 'args' into an argv array.  */
-      if ((argv = buildargv (args)) == NULL)
-	nomem (0);
-      else
-	make_cleanup_freeargv (argv);
+      argv = gdb_buildargv (args);
+      make_cleanup_freeargv (argv);
     }
   while (argv != NULL && *argv != NULL)
     {
Index: procfs.c
===================================================================
RCS file: /cvs/src/src/gdb/procfs.c,v
retrieving revision 1.94
diff -u -d -p -u -r1.94 procfs.c
--- procfs.c	22 Sep 2008 15:21:30 -0000	1.94
+++ procfs.c	26 Sep 2008 22:45:22 -0000
@@ -5853,10 +5853,8 @@ info_proc_cmd (char *args, int from_tty)
   old_chain = make_cleanup (null_cleanup, 0);
   if (args)
     {
-      if ((argv = buildargv (args)) == NULL)
-	nomem (0);
-      else
-	make_cleanup_freeargv (argv);
+      argv = gdb_buildargv (args);
+      make_cleanup_freeargv (argv);
     }
   while (argv != NULL && *argv != NULL)
     {
Index: remote-mips.c
===================================================================
RCS file: /cvs/src/src/gdb/remote-mips.c,v
retrieving revision 1.90
diff -u -d -p -u -r1.90 remote-mips.c
--- remote-mips.c	4 Sep 2008 22:49:30 -0000	1.90
+++ remote-mips.c	26 Sep 2008 22:45:23 -0000
@@ -1490,8 +1490,7 @@ device is attached to the target board (

   /* Parse the serial port name, the optional TFTP name, and the
      optional local TFTP name.  */
-  if ((argv = buildargv (name)) == NULL)
-    nomem (0);
+  argv = gdb_buildargv (name);
   make_cleanup_freeargv (argv);

   serial_port_name = xstrdup (argv[0]);
Index: remote-sim.c
===================================================================
RCS file: /cvs/src/src/gdb/remote-sim.c,v
retrieving revision 1.76
diff -u -d -p -u -r1.76 remote-sim.c
--- remote-sim.c	24 Sep 2008 16:37:24 -0000	1.76
+++ remote-sim.c	26 Sep 2008 22:45:23 -0000
@@ -406,11 +406,11 @@ gdbsim_kill (void)
 static void
 gdbsim_load (char *args, int fromtty)
 {
-  char **argv = buildargv (args);
+  char **argv = gdb_buildargv (args);
   char *prog;

-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+      error_no_arg (_("program to load"));

   make_cleanup_freeargv (argv);

@@ -472,7 +472,7 @@ gdbsim_create_inferior (char *exec_file,
       strcat (arg_buf, exec_file);
       strcat (arg_buf, " ");
       strcat (arg_buf, args);
-      argv = buildargv (arg_buf);
+      argv = gdb_buildargv (arg_buf);
       make_cleanup_freeargv (argv);
     }
   else
@@ -546,9 +546,7 @@ gdbsim_open (char *args, int from_tty)
       strcat (arg_buf, " ");	/* 1 */
       strcat (arg_buf, args);
     }
-  argv = buildargv (arg_buf);
-  if (argv == NULL)
-    error (_("Insufficient memory available to allocate simulator arg list."));
+  argv = gdb_buildargv (arg_buf);
   make_cleanup_freeargv (argv);

   init_callbacks ();
Index: remote.c
===================================================================
RCS file: /cvs/src/src/gdb/remote.c,v
retrieving revision 1.310
diff -u -d -p -u -r1.310 remote.c
--- remote.c	22 Sep 2008 15:21:30 -0000	1.310
+++ remote.c	26 Sep 2008 22:45:23 -0000
@@ -5546,13 +5546,16 @@ extended_remote_run (char *args)
     error (_("Remote file name too long for run packet"));
   len += 2 * bin2hex ((gdb_byte *) remote_exec_file, rs->buf + len, 0);

+  if (args == NULL)
+    error_no_arg (_("remote arguments"));
+
   if (*args)
     {
       struct cleanup *back_to;
       int i;
       char **argv;

-      argv = buildargv (args);
+      argv = gdb_buildargv (args);
       back_to = make_cleanup ((void (*) (void *)) freeargv, argv);
       for (i = 0; argv[i] != NULL; i++)
 	{
@@ -7491,9 +7494,10 @@ remote_put_command (char *args, int from
   struct cleanup *back_to;
   char **argv;

-  argv = buildargv (args);
-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+    error_no_arg (_("file to put"));
+
+  argv = gdb_buildargv (args);
   back_to = make_cleanup_freeargv (argv);
   if (argv[0] == NULL || argv[1] == NULL || argv[2] != NULL)
     error (_("Invalid parameters to remote put"));
@@ -7509,9 +7513,10 @@ remote_get_command (char *args, int from
   struct cleanup *back_to;
   char **argv;

-  argv = buildargv (args);
-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+    error_no_arg (_("file to get"));
+
+  argv = gdb_buildargv (args);
   back_to = make_cleanup_freeargv (argv);
   if (argv[0] == NULL || argv[1] == NULL || argv[2] != NULL)
     error (_("Invalid parameters to remote get"));
@@ -7527,9 +7532,10 @@ remote_delete_command (char *args, int f
   struct cleanup *back_to;
   char **argv;

-  argv = buildargv (args);
-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+    error_no_arg (_("file to delete"));
+
+  argv = gdb_buildargv (args);
   back_to = make_cleanup_freeargv (argv);
   if (argv[0] == NULL || argv[1] != NULL)
     error (_("Invalid parameters to remote delete"));
Index: ser-mingw.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-mingw.c,v
retrieving revision 1.14
diff -u -d -p -u -r1.14 ser-mingw.c
--- ser-mingw.c	3 Sep 2008 23:54:19 -0000	1.14
+++ ser-mingw.c	26 Sep 2008 22:45:23 -0000
@@ -818,12 +818,15 @@ pipe_windows_open (struct serial *scb, c
   struct pipe_state *ps;
   FILE *pex_stderr;

-  char **argv = buildargv (name);
+  if (name == NULL)
+    error_no_arg (_("child command"));
+
+  char **argv = gdb_buildargv (name);
   struct cleanup *back_to = make_cleanup_freeargv (argv);
+
   if (! argv[0] || argv[0][0] == '\0')
     error ("missing child command");

-
   ps = make_pipe_state ();
   make_cleanup (cleanup_pipe_state, ps);

Index: source.c
===================================================================
RCS file: /cvs/src/src/gdb/source.c,v
retrieving revision 1.91
diff -u -d -p -u -r1.91 source.c
--- source.c	11 Sep 2008 14:21:49 -0000	1.91
+++ source.c	26 Sep 2008 22:45:23 -0000
@@ -428,12 +428,9 @@ add_path (char *dirname, char **which_pa
       /* This will properly parse the space and tab separators
 	 and any quotes that may exist. DIRNAME_SEPARATOR will
 	 be dealt with later.  */
-      argv = buildargv (dirname);
+      argv = gdb_buildargv (dirname);
       make_cleanup_freeargv (argv);

-      if (argv == NULL)
-	nomem (0);
-
       arg = argv[0];
     }
   else
@@ -1813,7 +1810,7 @@ show_substitute_path_command (char *args
   char **argv;
   char *from = NULL;

-  argv = buildargv (args);
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);

   /* We expect zero or one argument.  */
@@ -1846,7 +1843,7 @@ static void
 unset_substitute_path_command (char *args, int from_tty)
 {
   struct substitute_path_rule *rule = substitute_path_rules;
-  char **argv = buildargv (args);
+  char **argv = gdb_buildargv (args);
   char *from = NULL;
   int rule_found = 0;

@@ -1899,7 +1896,7 @@ set_substitute_path_command (char *args,
   char **argv;
   struct substitute_path_rule *rule;

-  argv = buildargv (args);
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);

   if (argv == NULL || argv[0] == NULL || argv [1] == NULL)
Index: stack.c
===================================================================
RCS file: /cvs/src/src/gdb/stack.c,v
retrieving revision 1.179
diff -u -d -p -u -r1.179 stack.c
--- stack.c	25 Sep 2008 16:04:11 -0000	1.179
+++ stack.c	26 Sep 2008 22:45:23 -0000
@@ -1282,7 +1282,7 @@ backtrace_command (char *arg, int from_t
       char **argv;
       int i;

-      argv = buildargv (arg);
+      argv = gdb_buildargv (arg);
       old_chain = make_cleanup_freeargv (argv);
       argc = 0;
       for (i = 0; argv[i]; i++)
Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.216
diff -u -d -p -u -r1.216 symfile.c
--- symfile.c	22 Sep 2008 18:18:07 -0000	1.216
+++ symfile.c	26 Sep 2008 22:45:23 -0000
@@ -1488,14 +1488,11 @@ symbol_file_command (char *args, int fro
     }
   else
     {
-      char **argv = buildargv (args);
+      char **argv = gdb_buildargv (args);
       int flags = OBJF_USERLOADED;
       struct cleanup *cleanups;
       char *name = NULL;

-      if (argv == NULL)
-	nomem (0);
-
       cleanups = make_cleanup_freeargv (argv);
       while (*argv != NULL)
 	{
@@ -1929,11 +1926,7 @@ generic_load (char *args, int from_tty)

   make_cleanup (clear_memory_write_data, &cbdata.requests);

-  argv = buildargv (args);
-
-  if (argv == NULL)
-    nomem(0);
-
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);

   filename = tilde_expand (argv[0]);
@@ -2122,12 +2115,9 @@ add_symbol_file_command (char *args, int
   if (args == NULL)
     error (_("add-symbol-file takes a file name and an address"));

-  argv = buildargv (args);
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);

-  if (argv == NULL)
-    nomem (0);
-
   for (arg = argv[0], argcnt = 0; arg != NULL; arg = argv[++argcnt])
     {
       /* Process the argument. */
Index: symmisc.c
===================================================================
RCS file: /cvs/src/src/gdb/symmisc.c,v
retrieving revision 1.56
diff -u -d -p -u -r1.56 symmisc.c
--- symmisc.c	5 Sep 2008 11:37:17 -0000	1.56
+++ symmisc.c	26 Sep 2008 22:45:23 -0000
@@ -526,10 +526,7 @@ maintenance_print_symbols (char *args, i
       error (_("\
 Arguments missing: an output file name and an optional symbol file name"));
     }
-  else if ((argv = buildargv (args)) == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   cleanups = make_cleanup_freeargv (argv);

   if (argv[0] != NULL)
@@ -739,10 +736,7 @@ maintenance_print_psymbols (char *args,
     {
       error (_("print-psymbols takes an output file name and optional
symbol file name"));
     }
-  else if ((argv = buildargv (args)) == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   cleanups = make_cleanup_freeargv (argv);

   if (argv[0] != NULL)
@@ -878,10 +872,7 @@ maintenance_print_msymbols (char *args,
     {
       error (_("print-msymbols takes an output file name and optional
symbol file name"));
     }
-  else if ((argv = buildargv (args)) == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   cleanups = make_cleanup_freeargv (argv);

   if (argv[0] != NULL)
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/utils.c,v
retrieving revision 1.195
diff -u -d -p -u -r1.195 utils.c
--- utils.c	8 Sep 2008 21:57:42 -0000	1.195
+++ utils.c	26 Sep 2008 22:45:23 -0000
@@ -3349,3 +3349,12 @@ ldirname (const char *filename)
   dirname[base - filename] = '\0';
   return dirname;
 }
+
+char **
+gdb_buildargv (const char *s)
+{
+  char **argv = buildargv (s);
+  if (s != NULL && argv == NULL)
+    nomem (0);
+  return argv;
+}


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [patch] Re: GDB aborts on missing command args. Which way to fix?
  2008-09-26 23:22     ` [patch] " Paul Pluzhnikov
@ 2008-10-03  7:04       ` Joel Brobecker
  2008-10-03 16:39         ` Paul Pluzhnikov
  0 siblings, 1 reply; 6+ messages in thread
From: Joel Brobecker @ 2008-10-03  7:04 UTC (permalink / raw)
  To: Paul Pluzhnikov; +Cc: Tom Tromey, gdb-patches

> 	* remote-sim.c (gdbsim_kill, gdbsim_create_inferior,
> 	gdbsim_open): Likewise.

Minor detail. You need to close the parens on the first line, and
then reopen it on the next line. This is what the GNU Coding Standards
require. So:

  	* remote-sim.c (gdbsim_kill, gdbsim_create_inferior)
  	(gdbsim_open): Likewise.

You have other cases of the same issues in the changelog, so please
be sure to fix these as well.

> @@ -371,11 +371,11 @@ interpreter_exec_cmd (char *args, int fr
>    unsigned int i;
>    int old_quiet, use_quiet;
> 
> -  prules = buildargv (args);
> +  prules = gdb_buildargv (args);
>    if (prules == NULL)
> -    {
> -      error (_("unable to parse arguments"));
> -    }
> +    error (_("unable to parse arguments"));
> +  else
> +    make_cleanup_freeargv (prules);

I think it would be nice to be consistent in the way we are handling
the argument.  In this case, it's a bit obscure at first sight what
it would mean for prules to be NULL.  You have to know the semantics
of gdb_buildargv and determine from there that the only way it can
be null is if args is NULL as well.  How about we change this to:

  if (args == NULL)
    error_no_arg (_("interpreter-exec command"));
  prules = gdb_buildargv (args)
  make_cleanup_freeargv (prules)

?

> -  char **argv = buildargv (args);
> +  char **argv = gdb_buildargv (args);
>    char *prog;
> 
> -  if (argv == NULL)
> -    nomem (0);
> +  if (args == NULL)
> +      error_no_arg (_("program to load"));

I guess I'm being a little anal about this, but it's strange to be using
args before you check whether it's null or not.  I know gdb_buildargv
would return NULL is args is NULL, but can you move the call after
the check for args.

> @@ -5546,13 +5546,16 @@ extended_remote_run (char *args)
>      error (_("Remote file name too long for run packet"));
>    len += 2 * bin2hex ((gdb_byte *) remote_exec_file, rs->buf + len, 0);
> 
> +  if (args == NULL)
> +    error_no_arg (_("remote arguments"));

This should never happen. There are a few indirections involved, but
essentially thiis function is called from "run_command" in infcmd,
and ARGS is pretty much guaranteed to be non NULL.

Two options: Add a "gdb_assert (args != NULL);" or make the function
handle the case where args is NULL the same as if args == "". For that,
changing the following if should work:

>    if (*args)

    if (args && *args).


> @@ -1929,11 +1926,7 @@ generic_load (char *args, int from_tty)
> 
>    make_cleanup (clear_memory_write_data, &cbdata.requests);
> 
> -  argv = buildargv (args);
> -
> -  if (argv == NULL)
> -    nomem(0);
> -
> +  argv = gdb_buildargv (args);
>    make_cleanup_freeargv (argv);

I think this one is missing the check for args first. The rest
of this function is accessing argv freely, so it's definitely
expecting argv to be non-null, which means args must be non-null.

> +
> +char **
> +gdb_buildargv (const char *s)
> +{
> +  char **argv = buildargv (s);
> +  if (s != NULL && argv == NULL)
> +    nomem (0);
> +  return argv;
> +}

Can you add a comment just before the function that explains what
the function does, exactly.  I think it's fine to describe the function
compared to what libiberty's buildargv does.  Something like this:

/* Call libiberty's buildargv, and return the result, except that
   it calls nomem if buildargv ran out of memory.  Therefore, the
   returned value is guarantied to be non-NULL unless S is null.  */

Your patch is pre-approved with the corrections mentioned above.
Nice cleanup!

-- 
Joel


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [patch] Re: GDB aborts on missing command args. Which way to fix?
  2008-10-03  7:04       ` Joel Brobecker
@ 2008-10-03 16:39         ` Paul Pluzhnikov
  0 siblings, 0 replies; 6+ messages in thread
From: Paul Pluzhnikov @ 2008-10-03 16:39 UTC (permalink / raw)
  To: Joel Brobecker; +Cc: Tom Tromey, gdb-patches

[-- Attachment #1: Type: text/plain, Size: 216 bytes --]

On Fri, Oct 3, 2008 at 12:03 AM, Joel Brobecker <brobecker@adacore.com> wrote:

> Your patch is pre-approved with the corrections mentioned above.

Thanks for the review. Checked in as attached.

-- 
Paul Pluzhnikov

[-- Attachment #2: gdb-buildargv-20081003.txt --]
[-- Type: text/plain, Size: 15473 bytes --]

2008-10-03  Paul Pluzhnikov  <ppluzhnikov@google.com>
	
	* utils.c, defs.h (gdb_buildargv): New fn. Wrap buildargv
	and check for out-of-memory condition.
	* exec.c (exec_file_command): Call it.
	* infrun.c (handle_command, xdb_handle_command): Likewise.
	* interps.c (interpreter_exec_cmd): Likewise.
	* linux-nat.c (linux_nat_info_proc_cmd): Likewise.
	* procfs.c (info_proc_cmd): Likewise.
	* remote-mips.c (common_open): Likewise.
	* remote-sim.c (gdbsim_kill, gdbsim_create_inferior)
	(gdbsim_open): Likewise.
	* remote.c (extended_remote_run, remote_put_command)
	(remote_get_command, remote_delete_command): Likewise.
	* ser-mingw.c (pipe_windows_open): Likesise.
	* source.c (add_path, show_substitute_path_command)
	(unset_substitute_path_command, set_substitute_path_command):
	Likewise.
	* stack.c (backtrace_command): Likewise.
	* symfile.c (symbol_file_command, generic_load)
	(add_symbol_file_command): Likesise.
	* symmisc.c (maintenance_print_symbols, maintenance_print_psymbols)
	(maintenance_print_msymbols): Likewise.

Index: defs.h
===================================================================
RCS file: /cvs/src/src/gdb/defs.h,v
retrieving revision 1.237
diff -u -p -u -r1.237 defs.h
--- defs.h	14 Sep 2008 06:37:18 -0000	1.237
+++ defs.h	3 Oct 2008 16:28:34 -0000
@@ -405,6 +405,8 @@ ULONGEST strtoulst (const char *num, con
 
 char *ldirname (const char *filename);
 
+char **gdb_buildargv (const char *);
+
 /* From demangle.c */
 
 extern void set_demangling_style (char *);
Index: exec.c
===================================================================
RCS file: /cvs/src/src/gdb/exec.c,v
retrieving revision 1.77
diff -u -p -u -r1.77 exec.c
--- exec.c	5 Sep 2008 11:37:17 -0000	1.77
+++ exec.c	3 Oct 2008 16:28:34 -0000
@@ -302,10 +302,7 @@ exec_file_command (char *args, int from_
       /* Scan through the args and pick up the first non option arg
          as the filename.  */
 
-      argv = buildargv (args);
-      if (argv == NULL)
-        nomem (0);
-
+      argv = gdb_buildargv (args);
       make_cleanup_freeargv (argv);
 
       for (; (*argv != NULL) && (**argv == '-'); argv++)
Index: infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.323
diff -u -p -u -r1.323 infrun.c
--- infrun.c	2 Oct 2008 15:48:06 -0000	1.323
+++ infrun.c	3 Oct 2008 16:28:35 -0000
@@ -4070,11 +4070,7 @@ handle_command (char *args, int from_tty
 
   /* Break the command line up into args. */
 
-  argv = buildargv (args);
-  if (argv == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   old_chain = make_cleanup_freeargv (argv);
 
   /* Walk through the args, looking for signal oursigs, signal names, and
@@ -4231,13 +4227,12 @@ xdb_handle_command (char *args, int from
   char **argv;
   struct cleanup *old_chain;
 
+  if (args == NULL)
+    error_no_arg (_("xdb command"));
+
   /* Break the command line up into args. */
 
-  argv = buildargv (args);
-  if (argv == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   old_chain = make_cleanup_freeargv (argv);
   if (argv[1] != (char *) NULL)
     {
Index: interps.c
===================================================================
RCS file: /cvs/src/src/gdb/interps.c,v
retrieving revision 1.28
diff -u -p -u -r1.28 interps.c
--- interps.c	28 Jul 2008 17:53:52 -0000	1.28
+++ interps.c	3 Oct 2008 16:28:35 -0000
@@ -371,20 +371,15 @@ interpreter_exec_cmd (char *args, int fr
   unsigned int i;
   int old_quiet, use_quiet;
 
-  prules = buildargv (args);
-  if (prules == NULL)
-    {
-      error (_("unable to parse arguments"));
-    }
+  if (args == NULL)
+    error_no_arg (_("interpreter-exec command"));
+
+  prules = gdb_buildargv (args);
+  make_cleanup_freeargv (prules);
 
   nrules = 0;
-  if (prules != NULL)
-    {
-      for (trule = prules; *trule != NULL; trule++)
-	{
-	  nrules++;
-	}
-    }
+  for (trule = prules; *trule != NULL; trule++)
+    nrules++;
 
   if (nrules < 2)
     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
Index: linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/linux-nat.c,v
retrieving revision 1.106
diff -u -p -u -r1.106 linux-nat.c
--- linux-nat.c	25 Sep 2008 14:13:44 -0000	1.106
+++ linux-nat.c	3 Oct 2008 16:28:35 -0000
@@ -3591,10 +3591,8 @@ linux_nat_info_proc_cmd (char *args, int
   if (args)
     {
       /* Break up 'args' into an argv array.  */
-      if ((argv = buildargv (args)) == NULL)
-	nomem (0);
-      else
-	make_cleanup_freeargv (argv);
+      argv = gdb_buildargv (args);
+      make_cleanup_freeargv (argv);
     }
   while (argv != NULL && *argv != NULL)
     {
Index: procfs.c
===================================================================
RCS file: /cvs/src/src/gdb/procfs.c,v
retrieving revision 1.94
diff -u -p -u -r1.94 procfs.c
--- procfs.c	22 Sep 2008 15:21:30 -0000	1.94
+++ procfs.c	3 Oct 2008 16:28:35 -0000
@@ -5853,10 +5853,8 @@ info_proc_cmd (char *args, int from_tty)
   old_chain = make_cleanup (null_cleanup, 0);
   if (args)
     {
-      if ((argv = buildargv (args)) == NULL)
-	nomem (0);
-      else
-	make_cleanup_freeargv (argv);
+      argv = gdb_buildargv (args);
+      make_cleanup_freeargv (argv);
     }
   while (argv != NULL && *argv != NULL)
     {
Index: remote-mips.c
===================================================================
RCS file: /cvs/src/src/gdb/remote-mips.c,v
retrieving revision 1.90
diff -u -p -u -r1.90 remote-mips.c
--- remote-mips.c	4 Sep 2008 22:49:30 -0000	1.90
+++ remote-mips.c	3 Oct 2008 16:28:35 -0000
@@ -1490,8 +1490,7 @@ device is attached to the target board (
 
   /* Parse the serial port name, the optional TFTP name, and the
      optional local TFTP name.  */
-  if ((argv = buildargv (name)) == NULL)
-    nomem (0);
+  argv = gdb_buildargv (name);
   make_cleanup_freeargv (argv);
 
   serial_port_name = xstrdup (argv[0]);
Index: remote-sim.c
===================================================================
RCS file: /cvs/src/src/gdb/remote-sim.c,v
retrieving revision 1.76
diff -u -p -u -r1.76 remote-sim.c
--- remote-sim.c	24 Sep 2008 16:37:24 -0000	1.76
+++ remote-sim.c	3 Oct 2008 16:28:35 -0000
@@ -406,12 +406,13 @@ gdbsim_kill (void)
 static void
 gdbsim_load (char *args, int fromtty)
 {
-  char **argv = buildargv (args);
+  char **argv;
   char *prog;
 
-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+      error_no_arg (_("program to load"));
 
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);
 
   prog = tilde_expand (argv[0]);
@@ -472,7 +473,7 @@ gdbsim_create_inferior (char *exec_file,
       strcat (arg_buf, exec_file);
       strcat (arg_buf, " ");
       strcat (arg_buf, args);
-      argv = buildargv (arg_buf);
+      argv = gdb_buildargv (arg_buf);
       make_cleanup_freeargv (argv);
     }
   else
@@ -546,9 +547,7 @@ gdbsim_open (char *args, int from_tty)
       strcat (arg_buf, " ");	/* 1 */
       strcat (arg_buf, args);
     }
-  argv = buildargv (arg_buf);
-  if (argv == NULL)
-    error (_("Insufficient memory available to allocate simulator arg list."));
+  argv = gdb_buildargv (arg_buf);
   make_cleanup_freeargv (argv);
 
   init_callbacks ();
Index: remote.c
===================================================================
RCS file: /cvs/src/src/gdb/remote.c,v
retrieving revision 1.310
diff -u -p -u -r1.310 remote.c
--- remote.c	22 Sep 2008 15:21:30 -0000	1.310
+++ remote.c	3 Oct 2008 16:28:35 -0000
@@ -5546,13 +5546,14 @@ extended_remote_run (char *args)
     error (_("Remote file name too long for run packet"));
   len += 2 * bin2hex ((gdb_byte *) remote_exec_file, rs->buf + len, 0);
 
+  gdb_assert (args != NULL);
   if (*args)
     {
       struct cleanup *back_to;
       int i;
       char **argv;
 
-      argv = buildargv (args);
+      argv = gdb_buildargv (args);
       back_to = make_cleanup ((void (*) (void *)) freeargv, argv);
       for (i = 0; argv[i] != NULL; i++)
 	{
@@ -7491,9 +7492,10 @@ remote_put_command (char *args, int from
   struct cleanup *back_to;
   char **argv;
 
-  argv = buildargv (args);
-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+    error_no_arg (_("file to put"));
+
+  argv = gdb_buildargv (args);
   back_to = make_cleanup_freeargv (argv);
   if (argv[0] == NULL || argv[1] == NULL || argv[2] != NULL)
     error (_("Invalid parameters to remote put"));
@@ -7509,9 +7511,10 @@ remote_get_command (char *args, int from
   struct cleanup *back_to;
   char **argv;
 
-  argv = buildargv (args);
-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+    error_no_arg (_("file to get"));
+
+  argv = gdb_buildargv (args);
   back_to = make_cleanup_freeargv (argv);
   if (argv[0] == NULL || argv[1] == NULL || argv[2] != NULL)
     error (_("Invalid parameters to remote get"));
@@ -7527,9 +7530,10 @@ remote_delete_command (char *args, int f
   struct cleanup *back_to;
   char **argv;
 
-  argv = buildargv (args);
-  if (argv == NULL)
-    nomem (0);
+  if (args == NULL)
+    error_no_arg (_("file to delete"));
+
+  argv = gdb_buildargv (args);
   back_to = make_cleanup_freeargv (argv);
   if (argv[0] == NULL || argv[1] != NULL)
     error (_("Invalid parameters to remote delete"));
Index: ser-mingw.c
===================================================================
RCS file: /cvs/src/src/gdb/ser-mingw.c,v
retrieving revision 1.14
diff -u -p -u -r1.14 ser-mingw.c
--- ser-mingw.c	3 Sep 2008 23:54:19 -0000	1.14
+++ ser-mingw.c	3 Oct 2008 16:28:35 -0000
@@ -818,12 +818,15 @@ pipe_windows_open (struct serial *scb, c
   struct pipe_state *ps;
   FILE *pex_stderr;
 
-  char **argv = buildargv (name);
+  if (name == NULL)
+    error_no_arg (_("child command"));
+
+  char **argv = gdb_buildargv (name);
   struct cleanup *back_to = make_cleanup_freeargv (argv);
+
   if (! argv[0] || argv[0][0] == '\0')
     error ("missing child command");
 
-
   ps = make_pipe_state ();
   make_cleanup (cleanup_pipe_state, ps);
 
Index: source.c
===================================================================
RCS file: /cvs/src/src/gdb/source.c,v
retrieving revision 1.91
diff -u -p -u -r1.91 source.c
--- source.c	11 Sep 2008 14:21:49 -0000	1.91
+++ source.c	3 Oct 2008 16:28:35 -0000
@@ -428,12 +428,9 @@ add_path (char *dirname, char **which_pa
       /* This will properly parse the space and tab separators
 	 and any quotes that may exist. DIRNAME_SEPARATOR will
 	 be dealt with later.  */
-      argv = buildargv (dirname);
+      argv = gdb_buildargv (dirname);
       make_cleanup_freeargv (argv);
 
-      if (argv == NULL)
-	nomem (0);
-
       arg = argv[0];
     }
   else
@@ -1813,7 +1810,7 @@ show_substitute_path_command (char *args
   char **argv;
   char *from = NULL;
   
-  argv = buildargv (args);
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);
 
   /* We expect zero or one argument.  */
@@ -1846,7 +1843,7 @@ static void
 unset_substitute_path_command (char *args, int from_tty)
 {
   struct substitute_path_rule *rule = substitute_path_rules;
-  char **argv = buildargv (args);
+  char **argv = gdb_buildargv (args);
   char *from = NULL;
   int rule_found = 0;
 
@@ -1899,7 +1896,7 @@ set_substitute_path_command (char *args,
   char **argv;
   struct substitute_path_rule *rule;
   
-  argv = buildargv (args);
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);
 
   if (argv == NULL || argv[0] == NULL || argv [1] == NULL)
Index: stack.c
===================================================================
RCS file: /cvs/src/src/gdb/stack.c,v
retrieving revision 1.179
diff -u -p -u -r1.179 stack.c
--- stack.c	25 Sep 2008 16:04:11 -0000	1.179
+++ stack.c	3 Oct 2008 16:28:35 -0000
@@ -1282,7 +1282,7 @@ backtrace_command (char *arg, int from_t
       char **argv;
       int i;
 
-      argv = buildargv (arg);
+      argv = gdb_buildargv (arg);
       old_chain = make_cleanup_freeargv (argv);
       argc = 0;
       for (i = 0; argv[i]; i++)
Index: symfile.c
===================================================================
RCS file: /cvs/src/src/gdb/symfile.c,v
retrieving revision 1.217
diff -u -p -u -r1.217 symfile.c
--- symfile.c	1 Oct 2008 17:21:06 -0000	1.217
+++ symfile.c	3 Oct 2008 16:28:35 -0000
@@ -1483,14 +1483,11 @@ symbol_file_command (char *args, int fro
     }
   else
     {
-      char **argv = buildargv (args);
+      char **argv = gdb_buildargv (args);
       int flags = OBJF_USERLOADED;
       struct cleanup *cleanups;
       char *name = NULL;
 
-      if (argv == NULL)
-	nomem (0);
-
       cleanups = make_cleanup_freeargv (argv);
       while (*argv != NULL)
 	{
@@ -1924,11 +1921,10 @@ generic_load (char *args, int from_tty)
 
   make_cleanup (clear_memory_write_data, &cbdata.requests);
 
-  argv = buildargv (args);
-
-  if (argv == NULL)
-    nomem(0);
+  if (args == NULL)
+    error_no_arg (_("file to load"));
 
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);
 
   filename = tilde_expand (argv[0]);
@@ -2117,12 +2113,9 @@ add_symbol_file_command (char *args, int
   if (args == NULL)
     error (_("add-symbol-file takes a file name and an address"));
 
-  argv = buildargv (args);
+  argv = gdb_buildargv (args);
   make_cleanup_freeargv (argv);
 
-  if (argv == NULL)
-    nomem (0);
-
   for (arg = argv[0], argcnt = 0; arg != NULL; arg = argv[++argcnt])
     {
       /* Process the argument. */
Index: symmisc.c
===================================================================
RCS file: /cvs/src/src/gdb/symmisc.c,v
retrieving revision 1.57
diff -u -p -u -r1.57 symmisc.c
--- symmisc.c	1 Oct 2008 16:56:52 -0000	1.57
+++ symmisc.c	3 Oct 2008 16:28:35 -0000
@@ -526,10 +526,7 @@ maintenance_print_symbols (char *args, i
       error (_("\
 Arguments missing: an output file name and an optional symbol file name"));
     }
-  else if ((argv = buildargv (args)) == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   cleanups = make_cleanup_freeargv (argv);
 
   if (argv[0] != NULL)
@@ -739,10 +736,7 @@ maintenance_print_psymbols (char *args, 
     {
       error (_("print-psymbols takes an output file name and optional symbol file name"));
     }
-  else if ((argv = buildargv (args)) == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   cleanups = make_cleanup_freeargv (argv);
 
   if (argv[0] != NULL)
@@ -878,10 +872,7 @@ maintenance_print_msymbols (char *args, 
     {
       error (_("print-msymbols takes an output file name and optional symbol file name"));
     }
-  else if ((argv = buildargv (args)) == NULL)
-    {
-      nomem (0);
-    }
+  argv = gdb_buildargv (args);
   cleanups = make_cleanup_freeargv (argv);
 
   if (argv[0] != NULL)
Index: utils.c
===================================================================
RCS file: /cvs/src/src/gdb/utils.c,v
retrieving revision 1.195
diff -u -p -u -r1.195 utils.c
--- utils.c	8 Sep 2008 21:57:42 -0000	1.195
+++ utils.c	3 Oct 2008 16:28:35 -0000
@@ -3349,3 +3349,17 @@ ldirname (const char *filename)
   dirname[base - filename] = '\0';
   return dirname;
 }
+
+/* Call libiberty's buildargv, and return the result.
+   If buildargv fails due to out-of-memory, call nomem.
+   Therefore, the returned value is guaranteed to be non-NULL,
+   unless the parameter itself is NULL.  */
+
+char **
+gdb_buildargv (const char *s)
+{
+  char **argv = buildargv (s);
+  if (s != NULL && argv == NULL)
+    nomem (0);
+  return argv;
+}

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2008-10-03 16:39 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-09-16 17:50 GDB aborts on missing command args. Which way to fix? Paul Pluzhnikov
2008-09-19 21:52 ` Tom Tromey
2008-09-19 22:02   ` Daniel Jacobowitz
2008-09-26 23:22     ` [patch] " Paul Pluzhnikov
2008-10-03  7:04       ` Joel Brobecker
2008-10-03 16:39         ` Paul Pluzhnikov

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