[RFA_v4 3/8] Add [FLAG]... arguments to 'thread apply'.

Philippe Waroquiers
2018-07-10T21:39:46Z

Enhance 'thread apply' command to also accept [FLAG]... arguments.

An example usage for this new argument:
thread apply all -s frame apply all -s p some_local_var_somewhere
Prints the thread id, frame location and some_local_var_somewhere
value in frames of threads that have such local var.

To make the life of the user easier, the most typical use cases
have shortcuts :
taas : shortcut for 'thread apply all -s'
tfaas : shortcut for 'thread apply all -s frame apply all -s"

An example usage :
tfaas p some_local_var_somewhere
same as the longer:
'thread apply all -s frame apply all -s p some_local_var_somewhere'

gdb/ChangeLog
2018-07-09 Philippe Waroquiers <philippe.waroquiers@skynet.be>

* thread.c (thr_try_catch_cmd): New function.
(thread_apply_all_command): Handle qcs flags.
(thread_apply_command): Handle qcs flags.
(taas_command): New function.
(tfaas_command): New function.
(_initialize_thread): Update to setup the new commands 'taas
and 'tfaas'. Change doc string for 'thread apply'.
---
gdb/thread.c | 133 +++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 109 insertions(+), 24 deletions(-)

diff --git a/gdb/thread.c b/gdb/thread.c
index 517a80715e..5071fdb27f 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -1583,6 +1583,44 @@ tp_array_compar (const thread_info *a, const thread_info *b)
return (a->per_inf_num > b->per_inf_num);
}

+/* Switch to thread THR and execute CMD.
+ FLAGS.QUIET controls the printing of the thread information.
+ FLAGS.CONT and FLAGS.SILENT control how to handle errors. */
+
+static void
+thr_try_catch_cmd (thread_info *thr, const char *cmd, int from_tty,
+ const qcs_flags &flags)
+{
+ switch_to_thread (thr);
+ TRY
+ {
+ std::string cmd_result = execute_command_to_string (cmd, from_tty);
+ if (!flags.silent || cmd_result.length () > 0)
+ {
+ if (!flags.quiet)
+ printf_filtered (_("\nThread %s (%s):\n"),
+ print_thread_id (thr),
+ target_pid_to_str (inferior_ptid));
+ printf_filtered ("%s", cmd_result.c_str ());
+ }
+ }
+ CATCH (ex, RETURN_MASK_ERROR)
+ {
+ if (!flags.silent)
+ {
+ if (!flags.quiet)
+ printf_filtered (_("\nThread %s (%s):\n"),
+ print_thread_id (thr),
+ target_pid_to_str (inferior_ptid));
+ if (flags.cont)
+ printf_filtered ("%s\n", ex.message);
+ else
+ throw_exception (ex);
+ }
+ }
+ END_CATCH;
+}
+
/* Apply a GDB command to a list of threads. List syntax is a whitespace
separated list of numbers, or ranges, or the keyword `all'. Ranges consist
of two numbers separated by a hyphen. Examples:
@@ -1594,16 +1632,27 @@ tp_array_compar (const thread_info *a, const thread_info *b)
static void
thread_apply_all_command (const char *cmd, int from_tty)
{
+ qcs_flags flags;
+
tp_array_compar_ascending = false;
- if (cmd != NULL
- && check_for_argument (&cmd, "-ascending", strlen ("-ascending")))
+
+ while (cmd != NULL)
{
- cmd = skip_spaces (cmd);
- tp_array_compar_ascending = true;
+ if (check_for_argument (&cmd, "-ascending", strlen ("-ascending")))
+ {
+ cmd = skip_spaces (cmd);
+ tp_array_compar_ascending = true;
+ continue;
+ }
+
+ if (parse_flags_qcs ("thread apply all", &cmd, &flags))
+ continue;
+
+ break;
}

if (cmd == NULL || *cmd == '\000')
- error (_("Please specify a command following the thread ID list"));
+ error (_("Please specify a command at the end of 'thread apply all'"));

update_thread_list ();

@@ -1639,14 +1688,7 @@ thread_apply_all_command (const char *cmd, int from_tty)

for (thread_info *thr : thr_list_cpy)
if (thread_alive (thr))
- {
- switch_to_thread (thr);
- printf_filtered (_("\nThread %s (%s):\n"),
- print_thread_id (thr),
- target_pid_to_str (inferior_ptid));
-
- execute_command (cmd, from_tty);
- }
+ thr_try_catch_cmd (thr, cmd, from_tty, flags);
}
}

@@ -1655,7 +1697,9 @@ thread_apply_all_command (const char *cmd, int from_tty)
static void
thread_apply_command (const char *tidlist, int from_tty)
{
+ qcs_flags flags;
const char *cmd = NULL;
+ const char *cmd_or_flags;
tid_range_parser parser;

if (tidlist == NULL || *tidlist == '\000')
@@ -1673,6 +1717,10 @@ thread_apply_command (const char *tidlist, int from_tty)
}
}

+ cmd_or_flags = cmd;
+ while (cmd != NULL && parse_flags_qcs ("thread apply", &cmd, &flags))
+ ;
+
if (cmd == NULL)
error (_("Please specify a command following the thread ID list"));

@@ -1682,7 +1730,7 @@ thread_apply_command (const char *tidlist, int from_tty)
scoped_restore_current_thread restore_thread;

parser.init (tidlist, current_inferior ()->num);
- while (!parser.finished () && parser.cur_tok () < cmd)
+ while (!parser.finished () && parser.cur_tok () < cmd_or_flags)
{
struct thread_info *tp = NULL;
struct inferior *inf;
@@ -1727,14 +1775,30 @@ thread_apply_command (const char *tidlist, int from_tty)
continue;
}

- switch_to_thread (tp);
-
- printf_filtered (_("\nThread %s (%s):\n"), print_thread_id (tp),
- target_pid_to_str (inferior_ptid));
- execute_command (cmd, from_tty);
+ thr_try_catch_cmd (tp, cmd, from_tty, flags);
}
}

+
+/* Implementation of the "taas" command. */
+
+static void
+taas_command (const char *cmd, int from_tty)
+{
+ std::string expanded = std::string ("thread apply all -s ") + cmd;
+ execute_command (expanded.c_str (), from_tty);
+}
+
+/* Implementation of the "tfaas" command. */
+
+static void
+tfaas_command (const char *cmd, int from_tty)
+{
+ std::string expanded
+ = std::string ("thread apply all -s frame apply all -s ") + cmd;
+ execute_command (expanded.c_str (), from_tty);
+}
+
/* Switch to the specified thread, or print the current thread. */

void
@@ -2032,22 +2096,43 @@ Use this command to switch between threads.\n\
The new thread ID must be currently known."),
&thread_cmd_list, "thread ", 1, &cmdlist);

+#define THREAD_APPLY_FLAGS_HELP "\
+Prints per-inferior thread number and target system's thread id\n\
+followed by COMMAND output.\n\
+FLAG arguments are -q (quiet), -c (continue), -s (silent).\n\
+Flag -q disables printing the thread information.\n\
+By default, if a COMMAND raises an error, thread apply is aborted.\n\
+Flag -c indicates to print the error and continue.\n\
+Flag -s indicates to silently ignore a COMMAND that raises an error\n\
+or produces no output."
+
add_prefix_cmd ("apply", class_run, thread_apply_command,
_("Apply a command to a list of threads.\n\
-Usage: thread apply ID... COMMAND\n\
-ID is a space-separated list of IDs of threads to apply COMMAND on."),
+Usage: thread apply ID... [FLAG]... COMMAND\n\
+ID is a space-separated list of IDs of threads to apply COMMAND on.\n"
+THREAD_APPLY_FLAGS_HELP),
&thread_apply_list, "thread apply ", 1, &thread_cmd_list);

add_cmd ("all", class_run, thread_apply_all_command,
_("\
Apply a command to all threads.\n\
\n\
-Usage: thread apply all [-ascending] COMMAND\n\
+Usage: thread apply all [-ascending] [FLAG]... COMMAND\n\
-ascending: Call COMMAND for all threads in ascending order.\n\
- The default is descending order.\
-"),
+ The default is descending order.\n"
+THREAD_APPLY_FLAGS_HELP),
&thread_apply_list);

+ add_com ("taas", class_run, taas_command, _("\
+Apply a command to all threads (ignoring errors and empty output).\n\
+Usage: taas COMMAND\n\
+shortcut for 'thread apply all -s COMMAND'"));
+
+ add_com ("tfaas", class_run, tfaas_command, _("\
+Apply a command to all frames of all threads (ignoring errors and empty output).\n\
+Usage: tfaas COMMAND\n\
+shortcut for 'thread apply all -s frame apply all -s COMMAND'"));
+
add_cmd ("name", class_run, thread_name_command,
_("Set the current thread's name.\n\
Usage: thread name [NAME]\n\
--
2.18.0