Per-inferior/Inferior-qualified thread IDs

This commit changes GDB to track thread numbers per-inferior.  Then,
if you're debugging multiple inferiors, GDB displays
"inferior-num.thread-num" instead of just "thread-num" whenever it
needs to display a thread:

 (gdb) info inferiors
   Num  Description       Executable
   1    process 6022     /home/pedro/gdb/tests/threads
 * 2    process 6037     /home/pedro/gdb/tests/threads
 (gdb) info threads
   Id   Target Id         Frame
   1.1  Thread 0x7ffff7fc2740 (LWP 6022) "threads" (running)
   1.2  Thread 0x7ffff77c0700 (LWP 6028) "threads" (running)
   1.3  Thread 0x7ffff7fc2740 (LWP 6032) "threads" (running)
   2.1  Thread 0x7ffff7fc1700 (LWP 6037) "threads" (running)
   2.2  Thread 0x7ffff77c0700 (LWP 6038) "threads" (running)
 * 2.3  Thread 0x7ffff7fc2740 (LWP 6039) "threads" (running)
 (gdb)
...
 (gdb) thread 1.1
 [Switching to thread 1.1 (Thread 0x7ffff7fc2740 (LWP 8155))]
 (gdb)
...

etc.

You can still use "thread NUM", in which case GDB infers you're
referring to thread NUM of the current inferior.

The $_thread convenience var and Python's InferiorThread.num attribute
are remapped to the new per-inferior thread number.  It's a backward
compatibility break, but since it only matters when debugging multiple
inferiors, I think it's worth doing.

Because MI thread IDs need to be a single integer, we keep giving
threads a global identifier, _in addition_ to the per-inferior number,
and make MI always refer to the global thread IDs.  IOW, nothing
changes from a MI frontend's perspective.

Similarly, since Python's Breakpoint.thread and Guile's
breakpoint-thread/set-breakpoint-thread breakpoint methods need to
work with integers, those are adjusted to work with global thread IDs
too.  Follow up patches will provide convenient means to access
threads' global IDs.

To avoid potencially confusing users (which also avoids updating much
of the testsuite), if there's only one inferior and its ID is "1",
IOW, the user hasn't done anything multi-process/inferior related,
then the "INF." part of thread IDs is not shown.  E.g,.:

 (gdb) info inferiors
   Num  Description       Executable
 * 1    process 15275     /home/pedro/gdb/tests/threads
 (gdb) info threads
   Id   Target Id         Frame
 * 1    Thread 0x7ffff7fc1740 (LWP 15275) "threads" main () at threads.c:40
 (gdb) add-inferior
 Added inferior 2
 (gdb) info threads
   Id   Target Id         Frame
 * 1.1  Thread 0x7ffff7fc1740 (LWP 15275) "threads" main () at threads.c:40
 (gdb)

No regressions on x86_64 Fedora 20.

gdb/ChangeLog:
2016-01-13  Pedro Alves  <palves@redhat.com>

	* NEWS: Mention that thread IDs are now per inferior and global
	thread IDs.
	* Makefile.in (SFILES): Add tid-parse.c.
	(COMMON_OBS): Add tid-parse.o.
	(HFILES_NO_SRCDIR): Add tid-parse.h.
	* ada-tasks.c: Adjust to use ptid_to_global_thread_id.
	* breakpoint.c (insert_breakpoint_locations)
	(remove_threaded_breakpoints, bpstat_check_breakpoint_conditions)
	(print_one_breakpoint_location, set_longjmp_breakpoint)
	(check_longjmp_breakpoint_for_call_dummy)
	(set_momentary_breakpoint): Adjust to use global IDs.
	(find_condition_and_thread, watch_command_1): Use parse_thread_id.
	(until_break_command, longjmp_bkpt_dtor)
	(breakpoint_re_set_thread, insert_single_step_breakpoint): Adjust
	to use global IDs.
	* dummy-frame.c (pop_dummy_frame_bpt): Adjust to use
	ptid_to_global_thread_id.
	* elfread.c (elf_gnu_ifunc_resolver_stop): Likewise.
	* gdbthread.h (struct thread_info): Rename field 'num' to
	'global_num.  Add new fields 'per_inf_num' and 'inf'.
	(thread_id_to_pid): Rename thread_id_to_pid to
	global_thread_id_to_ptid.
	(pid_to_thread_id): Rename to ...
	(ptid_to_global_thread_id): ... this.
	(valid_thread_id): Rename to ...
	(valid_global_thread_id): ... this.
	(find_thread_id): Rename to ...
	(find_thread_global_id): ... this.
	(ALL_THREADS, ALL_THREADS_BY_INFERIOR): Declare.
	(print_thread_info): Add comment.
	* tid-parse.h: New file.
	* tid-parse.c: New file.
	* infcmd.c (step_command_fsm_prepare)
	(step_command_fsm_should_stop): Adjust to use the global thread
	ID.
	(until_next_command, until_next_command)
	(finish_command_fsm_should_stop): Adjust to use the global thread
	ID.
	(attach_post_wait): Adjust to check the inferior number too.
	* inferior.h (struct inferior) <highest_thread_num>: New field.
	* infrun.c (handle_signal_stop)
	(insert_exception_resume_breakpoint)
	(insert_exception_resume_from_probe): Adjust to use the global
	thread ID.
	* record-btrace.c (record_btrace_open): Use global thread IDs.
	* remote.c (process_initial_stop_replies): Also consider the
	inferior number.
	* target.c (target_pre_inferior): Clear the inferior's highest
	thread num.
	* thread.c (clear_thread_inferior_resources): Adjust to use the
	global thread ID.
	(new_thread): New inferior parameter.  Adjust to use it.  Set both
	the thread's global ID and the thread's per-inferior ID.
	(add_thread_silent): Adjust.
	(find_thread_global_id): New.
	(find_thread_id): Make static.  Adjust to rename.
	(valid_thread_id): Rename to ...
	(valid_global_thread_id): ... this.
	(pid_to_thread_id): Rename to ...
	(ptid_to_global_thread_id): ... this.
	(thread_id_to_pid): Rename to ...
	(global_thread_id_to_ptid): ... this.  Adjust.
	(first_thread_of_process): Adjust.
	(do_captured_list_thread_ids): Adjust to use global thread IDs.
	(should_print_thread): New function.
	(print_thread_info): Rename to ...
	(print_thread_info_1): ... this, and add new show_global_ids
	parameter.  Handle it.  Iterate over inferiors.
	(print_thread_info): Reimplement as wrapper around
	print_thread_info_1.
	(show_inferior_qualified_tids): New function.
	(print_thread_id): Use it.
	(tp_array_compar): Compare inferior numbers too.
	(thread_apply_command): Use tid_range_parser.
	(do_captured_thread_select): Use parse_thread_id.
	(thread_id_make_value): Adjust.
	(_initialize_thread): Adjust "info threads" help string.
	* varobj.c (struct varobj_root): Update comment.
	(varobj_create): Adjust to use global thread IDs.
	(value_of_root_1): Adjust to use global_thread_id_to_ptid.
	* windows-tdep.c (display_tib): No longer accept an argument.
	* cli/cli-utils.c (get_number_trailer): Make extern.
	* cli/cli-utils.h (get_number_trailer): Declare.
	(get_number_const): Adjust documentation.
	* mi/mi-cmd-var.c (mi_cmd_var_update_iter): Adjust to use global
	thread IDs.
	* mi/mi-interp.c (mi_new_thread, mi_thread_exit)
	(mi_on_normal_stop, mi_output_running_pid, mi_on_resume):
	* mi/mi-main.c (mi_execute_command, mi_cmd_execute): Likewise.
	* guile/scm-breakpoint.c (gdbscm_set_breakpoint_thread_x):
	Likewise.
	* python/py-breakpoint.c (bppy_set_thread): Likewise.
	* python/py-finishbreakpoint.c (bpfinishpy_init): Likewise.
	* python/py-infthread.c (thpy_get_num): Add comment and return the
	per-inferior thread ID.
	(thread_object_getset): Update comment of "num".

gdb/testsuite/ChangeLog:
2016-01-07  Pedro Alves  <palves@redhat.com>

	* gdb.base/break.exp: Adjust to output changes.
	* gdb.base/hbreak2.exp: Likewise.
	* gdb.base/sepdebug.exp: Likewise.
	* gdb.base/watch_thread_num.exp: Likewise.
	* gdb.linespec/keywords.exp: Likewise.
	* gdb.multi/info-threads.exp: Likewise.
	* gdb.threads/thread-find.exp: Likewise.
	* gdb.multi/tids.c: New file.
	* gdb.multi/tids.exp: New file.

gdb/doc/ChangeLog:
2016-01-07  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Threads): Document per-inferior thread IDs,
	qualified thread IDs, global thread IDs and thread ID lists.
	(Set Watchpoints, Thread-Specific Breakpoints): Adjust to refer to
	thread IDs.
	(Convenience Vars): Document the $_thread convenience variable.
	(Ada Tasks): Adjust to refer to thread IDs.
	(GDB/MI Async Records, GDB/MI Thread Commands, GDB/MI Ada Tasking
	Commands, GDB/MI Variable Objects): Update to mention global
	thread IDs.
	* guile.texi (Breakpoints In Guile)
	<breakpoint-thread/set-breakpoint-thread breakpoint>: Mention
	global thread IDs instead of thread IDs.
	* python.texi (Threads In Python): Adjust documentation of
	InferiorThread.num.
	(Breakpoint.thread): Mention global thread IDs instead of thread
	IDs.

1 files changed, 282 insertions, 0 deletions

diff --git a/gdb/tid-parse.c b/gdb/tid-parse.c
new file mode 100644
index 0000000..21b872d
--- /dev/null
+++ b/gdb/tid-parse.c
@@ -0,0 +1,282 @@
+/* TID parsing for GDB, the GNU debugger.
+
+   Copyright (C) 2015-2016 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 3 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, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "tid-parse.h"
+#include "inferior.h"
+#include "gdbthread.h"
+#include <ctype.h>
+
+/* See tid-parse.h.  */
+
+void ATTRIBUTE_NORETURN
+invalid_thread_id_error (const char *string)
+{
+  error (_("Invalid thread ID: %s"), string);
+}
+
+/* See tid-parse.h.  */
+
+struct thread_info *
+parse_thread_id (const char *tidstr, const char **end)
+{
+  const char *number = tidstr;
+  const char *dot, *p1;
+  struct thread_info *tp;
+  struct inferior *inf;
+  int thr_num;
+  int explicit_inf_id = 0;
+
+  dot = strchr (number, '.');
+
+  if (dot != NULL)
+    {
+      /* Parse number to the left of the dot.  */
+      int inf_num;
+
+      p1 = number;
+      inf_num = get_number_trailer (&p1, '.');
+      if (inf_num == 0)
+	invalid_thread_id_error (number);
+
+      inf = find_inferior_id (inf_num);
+      if (inf == NULL)
+	error (_("No inferior number '%d'"), inf_num);
+
+      explicit_inf_id = 1;
+      p1 = dot + 1;
+    }
+  else
+    {
+      inf = current_inferior ();
+
+      p1 = number;
+    }
+
+  thr_num = get_number_const (&p1);
+  if (thr_num == 0)
+    invalid_thread_id_error (number);
+
+  ALL_THREADS (tp)
+    {
+      if (ptid_get_pid (tp->ptid) == inf->pid
+	  && tp->per_inf_num == thr_num)
+	break;
+    }
+
+  if (tp == NULL)
+    {
+      if (show_inferior_qualified_tids () || explicit_inf_id)
+	error (_("Unknown thread %d.%d."), inf->num, thr_num);
+      else
+	error (_("Unknown thread %d."), thr_num);
+    }
+
+  if (end != NULL)
+    *end = p1;
+
+  return tp;
+}
+
+/* See tid-parse.h.  */
+
+void
+tid_range_parser_init (struct tid_range_parser *parser, const char *tidlist,
+		       int default_inferior)
+{
+  parser->state = TID_RANGE_STATE_INFERIOR;
+  parser->string = tidlist;
+  parser->inf_num = 0;
+  parser->qualified = 0;
+  parser->default_inferior = default_inferior;
+}
+
+/* See tid-parse.h.  */
+
+int
+tid_range_parser_finished (struct tid_range_parser *parser)
+{
+  switch (parser->state)
+    {
+    case TID_RANGE_STATE_INFERIOR:
+      return *parser->string == '\0';
+    case TID_RANGE_STATE_THREAD_RANGE:
+      return parser->range_parser.finished;
+    }
+
+  gdb_assert_not_reached (_("unhandled state"));
+}
+
+/* See tid-parse.h.  */
+
+const char *
+tid_range_parser_string (struct tid_range_parser *parser)
+{
+  switch (parser->state)
+    {
+    case TID_RANGE_STATE_INFERIOR:
+      return parser->string;
+    case TID_RANGE_STATE_THREAD_RANGE:
+      return parser->range_parser.string;
+    }
+
+  gdb_assert_not_reached (_("unhandled state"));
+}
+
+/* See tid-parse.h.  */
+
+void
+tid_range_parser_skip (struct tid_range_parser *parser)
+{
+  gdb_assert ((parser->state == TID_RANGE_STATE_THREAD_RANGE)
+	      && parser->range_parser.in_range);
+
+  tid_range_parser_init (parser, parser->range_parser.end_ptr,
+			 parser->default_inferior);
+}
+
+/* See tid-parse.h.  */
+
+int
+tid_range_parser_qualified (struct tid_range_parser *parser)
+{
+  return parser->qualified;
+}
+
+/* Helper for tid_range_parser_get_tid and
+   tid_range_parser_get_tid_range.  Return the next range if THR_END
+   is non-NULL, return a single thread ID otherwise.  */
+
+static int
+get_tid_or_range (struct tid_range_parser *parser, int *inf_num,
+		  int *thr_start, int *thr_end)
+{
+  if (parser->state == TID_RANGE_STATE_INFERIOR)
+    {
+      const char *p;
+      const char *space;
+
+      space = skip_to_space (parser->string);
+
+      p = parser->string;
+      while (p < space && *p != '.')
+	p++;
+      if (p < space)
+	{
+	  const char *dot = p;
+
+	  /* Parse number to the left of the dot.  */
+	  p = parser->string;
+	  parser->inf_num = get_number_trailer (&p, '.');
+	  if (parser->inf_num == 0)
+	    invalid_thread_id_error (parser->string);
+
+	  parser->qualified = 1;
+	  p = dot + 1;
+
+	  if (isspace (*p))
+	    invalid_thread_id_error (parser->string);
+	}
+      else
+	{
+	  parser->inf_num = parser->default_inferior;
+	  parser->qualified = 0;
+	  p = parser->string;
+	}
+
+      init_number_or_range (&parser->range_parser, p);
+      parser->state = TID_RANGE_STATE_THREAD_RANGE;
+    }
+
+  *inf_num = parser->inf_num;
+  *thr_start = get_number_or_range (&parser->range_parser);
+  if (*thr_start == 0)
+    invalid_thread_id_error (parser->string);
+
+  /* If we successfully parsed a thread number or finished parsing a
+     thread range, switch back to assuming the next TID is
+     inferior-qualified.  */
+  if (parser->range_parser.end_ptr == NULL
+      || parser->range_parser.string == parser->range_parser.end_ptr)
+    {
+      parser->state = TID_RANGE_STATE_INFERIOR;
+      parser->string = parser->range_parser.string;
+
+      if (thr_end != NULL)
+	*thr_end = *thr_start;
+    }
+
+  /* If we're midway through a range, and the caller wants the end
+     value, return it and skip to the end of the range.  */
+  if (thr_end != NULL && parser->state == TID_RANGE_STATE_THREAD_RANGE)
+    {
+      *thr_end = parser->range_parser.end_value;
+      tid_range_parser_skip (parser);
+    }
+
+  return (*inf_num != 0 && *thr_start != 0);
+}
+
+/* See tid-parse.h.  */
+
+int
+tid_range_parser_get_tid_range (struct tid_range_parser *parser, int *inf_num,
+				int *thr_start, int *thr_end)
+{
+  gdb_assert (inf_num != NULL && thr_start != NULL && thr_end != NULL);
+
+  return get_tid_or_range (parser, inf_num, thr_start, thr_end);
+}
+
+/* See tid-parse.h.  */
+
+int
+tid_range_parser_get_tid (struct tid_range_parser *parser,
+			  int *inf_num, int *thr_num)
+{
+  gdb_assert (inf_num != NULL && thr_num != NULL);
+
+  return get_tid_or_range (parser, inf_num, thr_num, NULL);
+}
+
+/* See tid-parse.h.  */
+
+int
+tid_is_in_list (const char *list, int default_inferior,
+		int inf_num, int thr_num)
+{
+  struct tid_range_parser parser;
+
+  if (list == NULL || *list == '\0')
+    return 1;
+
+  tid_range_parser_init (&parser, list, default_inferior);
+  while (!tid_range_parser_finished (&parser))
+    {
+      int tmp_inf, tmp_thr_start, tmp_thr_end;
+
+      if (!tid_range_parser_get_tid_range (&parser, &tmp_inf,
+					   &tmp_thr_start, &tmp_thr_end))
+	invalid_thread_id_error (parser.string);
+      if (tmp_inf == inf_num
+	  && tmp_thr_start <= thr_num && thr_num <= tmp_thr_end)
+	return 1;
+    }
+  return 0;
+}