X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fthread.c;h=640c4396c9bc3d993518460be7acba4b99c1c489;hb=f43845b38ec9ab8ef197a9201b2e9be2913df4b3;hp=7ffc65af811f2d3ff0daa9c95bb16557fbf9becc;hpb=2847920ae997ce7240f6d51979a8fc004b2abc9e;p=deliverable%2Fbinutils-gdb.git

diff --git a/gdb/thread.c b/gdb/thread.c
index 7ffc65af81..640c4396c9 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -1,24 +1,26 @@
 /* Multi-process/thread control for GDB, the GNU debugger.
-   Copyright 1986, 1987, 1988, 1993
+
+   Copyright 1986, 1987, 1988, 1993, 1994, 1995, 1996, 1997, 1998,
+   1999, 2000, 2001, 2002 Free Software Foundation, Inc.
 
    Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
-   Free Software Foundation, Inc.
 
-This file is part of GDB.
+   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 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.
+   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.  */
+   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 "symtab.h"
@@ -30,104 +32,130 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 #include "gdbthread.h"
 #include "command.h"
 #include "gdbcmd.h"
+#include "regcache.h"
+#include "gdb.h"
 
 #include <ctype.h>
 #include <sys/types.h>
 #include <signal.h>
+#include "ui-out.h"
 
-/*#include "lynxos-core.h"*/
+/*#include "lynxos-core.h" */
 
-struct thread_info
-{
-  struct thread_info *next;
-  int pid;			/* Actual process id */
-  int num;			/* Convenient handle */
-  CORE_ADDR prev_pc;		/* State from wait_for_inferior */
-  CORE_ADDR prev_func_start;
-  char *prev_func_name;
-  struct breakpoint *step_resume_breakpoint;
-  struct breakpoint *through_sigtramp_breakpoint;
-  CORE_ADDR step_range_start;
-  CORE_ADDR step_range_end;
-  CORE_ADDR step_frame_address;
-  int trap_expected;
-  int handling_longjmp;
-  int another_trap;
-};
+/* Definition of struct thread_info exported to gdbthread.h */
+
+/* Prototypes for exported functions. */
+
+void _initialize_thread (void);
+
+/* Prototypes for local functions. */
 
 static struct thread_info *thread_list = NULL;
 static int highest_thread_num;
 
-static void
-thread_command PARAMS ((char * tidstr, int from_tty));
+static struct thread_info *find_thread_id (int num);
 
-static void
-prune_threads PARAMS ((void));
+static void thread_command (char *tidstr, int from_tty);
+static void thread_apply_all_command (char *, int);
+static int thread_alive (struct thread_info *);
+static void info_threads_command (char *, int);
+static void thread_apply_command (char *, int);
+static void restore_current_thread (ptid_t);
+static void switch_to_thread (ptid_t ptid);
+static void prune_threads (void);
 
-static void
-switch_to_thread PARAMS ((int pid));
+void
+delete_step_resume_breakpoint (void *arg)
+{
+  struct breakpoint **breakpointp = (struct breakpoint **) arg;
+  struct thread_info *tp;
 
-static struct thread_info *
-find_thread_id PARAMS ((int num));
+  if (*breakpointp != NULL)
+    {
+      delete_breakpoint (*breakpointp);
+      for (tp = thread_list; tp; tp = tp->next)
+	if (tp->step_resume_breakpoint == *breakpointp)
+	  tp->step_resume_breakpoint = NULL;
 
-static void
-info_threads_command PARAMS ((char *, int));
+      *breakpointp = NULL;
+    }
+}
 
 static void
-restore_current_thread PARAMS ((int));
+free_thread (struct thread_info *tp)
+{
+  /* NOTE: this will take care of any left-over step_resume breakpoints,
+     but not any user-specified thread-specific breakpoints. */
+  if (tp->step_resume_breakpoint)
+    delete_breakpoint (tp->step_resume_breakpoint);
 
-static void
-thread_apply_all_command PARAMS ((char *, int));
+  /* FIXME: do I ever need to call the back-end to give it a
+     chance at this private data before deleting the thread?  */
+  if (tp->private)
+    xfree (tp->private);
 
-static void
-thread_apply_command PARAMS ((char *, int));
+  xfree (tp);
+}
 
 void
-init_thread_list ()
+init_thread_list (void)
 {
   struct thread_info *tp, *tpnext;
 
+  highest_thread_num = 0;
   if (!thread_list)
     return;
 
   for (tp = thread_list; tp; tp = tpnext)
     {
       tpnext = tp->next;
-      free (tp);
+      free_thread (tp);
     }
 
   thread_list = NULL;
-  highest_thread_num = 0;
 }
 
-void
-add_thread (pid)
-     int pid;
+/* add_thread now returns a pointer to the new thread_info, 
+   so that back_ends can initialize their private data.  */
+
+struct thread_info *
+add_thread (ptid_t ptid)
 {
   struct thread_info *tp;
 
-  tp = (struct thread_info *) xmalloc (sizeof (struct thread_info));
-
-  tp->pid = pid;
+  tp = (struct thread_info *) xmalloc (sizeof (*tp));
+  memset (tp, 0, sizeof (*tp));
+  tp->ptid = ptid;
   tp->num = ++highest_thread_num;
-  tp->prev_pc = 0;
-  tp->prev_func_start = 0;
-  tp->prev_func_name = NULL;
-  tp->step_range_start = 0;
-  tp->step_range_end = 0;
-  tp->step_frame_address =0;
-  tp->step_resume_breakpoint = 0;
-  tp->through_sigtramp_breakpoint = 0;
-  tp->handling_longjmp = 0;
-  tp->trap_expected = 0;
-  tp->another_trap = 0;
   tp->next = thread_list;
   thread_list = tp;
+  return tp;
+}
+
+void
+delete_thread (ptid_t ptid)
+{
+  struct thread_info *tp, *tpprev;
+
+  tpprev = NULL;
+
+  for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
+    if (ptid_equal (tp->ptid, ptid))
+      break;
+
+  if (!tp)
+    return;
+
+  if (tpprev)
+    tpprev->next = tp->next;
+  else
+    thread_list = tp->next;
+
+  free_thread (tp);
 }
 
 static struct thread_info *
-find_thread_id (num)
-    int num;
+find_thread_id (int num)
 {
   struct thread_info *tp;
 
@@ -138,9 +166,48 @@ find_thread_id (num)
   return NULL;
 }
 
+/* Find a thread_info by matching PTID.  */
+struct thread_info *
+find_thread_pid (ptid_t ptid)
+{
+  struct thread_info *tp;
+
+  for (tp = thread_list; tp; tp = tp->next)
+    if (ptid_equal (tp->ptid, ptid))
+      return tp;
+
+  return NULL;
+}
+
+/*
+ * Thread iterator function.
+ *
+ * Calls a callback function once for each thread, so long as
+ * the callback function returns false.  If the callback function
+ * returns true, the iteration will end and the current thread
+ * will be returned.  This can be useful for implementing a 
+ * search for a thread with arbitrary attributes, or for applying
+ * some operation to every thread.
+ *
+ * FIXME: some of the existing functionality, such as 
+ * "Thread apply all", might be rewritten using this functionality.
+ */
+
+struct thread_info *
+iterate_over_threads (int (*callback) (struct thread_info *, void *),
+		      void *data)
+{
+  struct thread_info *tp;
+
+  for (tp = thread_list; tp; tp = tp->next)
+    if ((*callback) (tp, data))
+      return tp;
+
+  return NULL;
+}
+
 int
-valid_thread_id (num)
-    int num;
+valid_thread_id (int num)
 {
   struct thread_info *tp;
 
@@ -152,267 +219,390 @@ valid_thread_id (num)
 }
 
 int
-pid_to_thread_id (pid)
-    int pid;
+pid_to_thread_id (ptid_t ptid)
 {
   struct thread_info *tp;
 
   for (tp = thread_list; tp; tp = tp->next)
-    if (tp->pid == pid)
+    if (ptid_equal (tp->ptid, ptid))
       return tp->num;
 
   return 0;
 }
 
-int
-thread_id_to_pid (num)
-    int num;
+ptid_t
+thread_id_to_pid (int num)
 {
   struct thread_info *thread = find_thread_id (num);
   if (thread)
-    return thread->pid;
+    return thread->ptid;
   else
-    return -1;
+    return pid_to_ptid (-1);
 }
 
 int
-in_thread_list (pid)
-    int pid;
+in_thread_list (ptid_t ptid)
 {
   struct thread_info *tp;
 
   for (tp = thread_list; tp; tp = tp->next)
-    if (tp->pid == pid)
+    if (ptid_equal (tp->ptid, ptid))
       return 1;
 
   return 0;			/* Never heard of 'im */
 }
 
+/* Print a list of thread ids currently known, and the total number of
+   threads. To be used from within catch_errors. */
+static int 
+do_captured_list_thread_ids (struct ui_out *uiout,
+			     void *arg)
+{
+  struct thread_info *tp;
+  int num = 0;
+
+  ui_out_tuple_begin (uiout, "thread-ids");
+
+  for (tp = thread_list; tp; tp = tp->next)
+    {
+      num++;
+      ui_out_field_int (uiout, "thread-id", tp->num);
+    }
+
+  ui_out_tuple_end (uiout);
+  ui_out_field_int (uiout, "number-of-threads", num);
+  return GDB_RC_OK;
+}
+
+/* Official gdblib interface function to get a list of thread ids and
+   the total number. */
+enum gdb_rc
+gdb_list_thread_ids (struct ui_out *uiout)
+{
+  return catch_exceptions (uiout, do_captured_list_thread_ids, NULL,
+			   NULL, RETURN_MASK_ALL);
+}
+
 /* Load infrun state for the thread PID.  */
 
-void load_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
-			trap_expected, step_resume_breakpoint,
-			through_sigtramp_breakpoint, step_range_start,
-			step_range_end, step_frame_address,
-			handling_longjmp, another_trap)
-     int pid;
-     CORE_ADDR *prev_pc;
-     CORE_ADDR *prev_func_start;
-     char **prev_func_name;
-     int *trap_expected;
-     struct breakpoint **step_resume_breakpoint;
-     struct breakpoint **through_sigtramp_breakpoint;
-     CORE_ADDR *step_range_start;
-     CORE_ADDR *step_range_end;
-     CORE_ADDR *step_frame_address;
-     int *handling_longjmp;
-     int *another_trap;
+void
+load_infrun_state (ptid_t ptid, 
+		   CORE_ADDR *prev_pc, 
+		   CORE_ADDR *prev_func_start,
+		   char **prev_func_name, 
+		   int *trap_expected,
+		   struct breakpoint **step_resume_breakpoint,
+		   struct breakpoint **through_sigtramp_breakpoint,
+		   CORE_ADDR *step_range_start, 
+		   CORE_ADDR *step_range_end,
+		   CORE_ADDR *step_frame_address, 
+		   int *handling_longjmp,
+		   int *another_trap, 
+		   int *stepping_through_solib_after_catch,
+		   bpstat *stepping_through_solib_catchpoints,
+		   int *stepping_through_sigtramp,
+		   int *current_line, 
+		   struct symtab **current_symtab, 
+		   CORE_ADDR *step_sp)
 {
   struct thread_info *tp;
 
   /* If we can't find the thread, then we're debugging a single threaded
      process.  No need to do anything in that case.  */
-  tp = find_thread_id (pid_to_thread_id (pid));
+  tp = find_thread_id (pid_to_thread_id (ptid));
   if (tp == NULL)
     return;
 
   *prev_pc = tp->prev_pc;
   *prev_func_start = tp->prev_func_start;
   *prev_func_name = tp->prev_func_name;
+  *trap_expected = tp->trap_expected;
   *step_resume_breakpoint = tp->step_resume_breakpoint;
+  *through_sigtramp_breakpoint = tp->through_sigtramp_breakpoint;
   *step_range_start = tp->step_range_start;
   *step_range_end = tp->step_range_end;
   *step_frame_address = tp->step_frame_address;
-  *through_sigtramp_breakpoint = tp->through_sigtramp_breakpoint;
   *handling_longjmp = tp->handling_longjmp;
-  *trap_expected = tp->trap_expected;
   *another_trap = tp->another_trap;
+  *stepping_through_solib_after_catch = tp->stepping_through_solib_after_catch;
+  *stepping_through_solib_catchpoints = tp->stepping_through_solib_catchpoints;
+  *stepping_through_sigtramp = tp->stepping_through_sigtramp;
+  *current_line = tp->current_line;
+  *current_symtab = tp->current_symtab;
+  *step_sp = tp->step_sp;
 }
 
 /* Save infrun state for the thread PID.  */
 
-void save_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
-			trap_expected, step_resume_breakpoint,
-			through_sigtramp_breakpoint, step_range_start,
-			step_range_end, step_frame_address,
-			handling_longjmp, another_trap)
-     int pid;
-     CORE_ADDR prev_pc;
-     CORE_ADDR prev_func_start;
-     char *prev_func_name;
-     int trap_expected;
-     struct breakpoint *step_resume_breakpoint;
-     struct breakpoint *through_sigtramp_breakpoint;
-     CORE_ADDR step_range_start;
-     CORE_ADDR step_range_end;
-     CORE_ADDR step_frame_address;
-     int handling_longjmp;
-     int another_trap;
+void
+save_infrun_state (ptid_t ptid, 
+		   CORE_ADDR prev_pc, 
+		   CORE_ADDR prev_func_start,
+		   char *prev_func_name, 
+		   int trap_expected,
+		   struct breakpoint *step_resume_breakpoint,
+		   struct breakpoint *through_sigtramp_breakpoint,
+		   CORE_ADDR step_range_start, 
+		   CORE_ADDR step_range_end,
+		   CORE_ADDR step_frame_address, 
+		   int handling_longjmp,
+		   int another_trap, 
+		   int stepping_through_solib_after_catch,
+		   bpstat stepping_through_solib_catchpoints,
+		   int stepping_through_sigtramp, 
+		   int current_line,
+		   struct symtab *current_symtab,
+		   CORE_ADDR step_sp)
 {
   struct thread_info *tp;
 
   /* If we can't find the thread, then we're debugging a single-threaded
      process.  Nothing to do in that case.  */
-  tp = find_thread_id (pid_to_thread_id (pid));
+  tp = find_thread_id (pid_to_thread_id (ptid));
   if (tp == NULL)
     return;
 
   tp->prev_pc = prev_pc;
   tp->prev_func_start = prev_func_start;
   tp->prev_func_name = prev_func_name;
+  tp->trap_expected = trap_expected;
   tp->step_resume_breakpoint = step_resume_breakpoint;
+  tp->through_sigtramp_breakpoint = through_sigtramp_breakpoint;
   tp->step_range_start = step_range_start;
   tp->step_range_end = step_range_end;
   tp->step_frame_address = step_frame_address;
-  tp->through_sigtramp_breakpoint = through_sigtramp_breakpoint;
   tp->handling_longjmp = handling_longjmp;
-  tp->trap_expected = trap_expected;
   tp->another_trap = another_trap;
+  tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
+  tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
+  tp->stepping_through_sigtramp = stepping_through_sigtramp;
+  tp->current_line = current_line;
+  tp->current_symtab = current_symtab;
+  tp->step_sp = step_sp;
 }
 
 /* Return true if TP is an active thread. */
 static int
-thread_alive (tp)
-     struct thread_info *tp;
+thread_alive (struct thread_info *tp)
 {
-  if (tp->pid == -1)
+  if (PIDGET (tp->ptid) == -1)
     return 0;
-  if (! target_thread_alive (tp->pid))
+  if (!target_thread_alive (tp->ptid))
     {
-      tp->pid = -1;	/* Mark it as dead */
+      tp->ptid = pid_to_ptid (-1);	/* Mark it as dead */
       return 0;
     }
   return 1;
 }
 
 static void
-prune_threads ()
+prune_threads (void)
 {
-  struct thread_info *tp, *tpprev, *next;
+  struct thread_info *tp, *next;
 
-  tpprev = 0;
   for (tp = thread_list; tp; tp = next)
     {
       next = tp->next;
       if (!thread_alive (tp))
-	{
-	  if (tpprev)
-	    tpprev->next = next;
-	  else
-	    thread_list  = next;
-	  free (tp);
-	}
-      else
-	tpprev = tp;
+	delete_thread (tp->ptid);
     }
 }
 
-/* Print information about currently known threads */
+/* Print information about currently known threads 
+
+ * Note: this has the drawback that it _really_ switches
+ *       threads, which frees the frame cache.  A no-side
+ *       effects info-threads command would be nicer.
+ */
 
 static void
-info_threads_command (arg, from_tty)
-     char *arg;
-     int from_tty;
+info_threads_command (char *arg, int from_tty)
 {
   struct thread_info *tp;
-  int current_pid = inferior_pid;
+  ptid_t current_ptid;
+  struct frame_info *cur_frame;
+  int saved_frame_level = frame_relative_level (selected_frame);
+  int counter;
+  char *extra_info;
 
   /* Avoid coredumps which would happen if we tried to access a NULL
      selected_frame.  */
-  if (!target_has_stack) error ("No stack.");
+  if (!target_has_stack)
+    error ("No stack.");
 
   prune_threads ();
+  target_find_new_threads ();
+  current_ptid = inferior_ptid;
   for (tp = thread_list; tp; tp = tp->next)
     {
-      if (tp->pid == current_pid)
+      if (ptid_equal (tp->ptid, current_ptid))
 	printf_filtered ("* ");
       else
 	printf_filtered ("  ");
 
-      printf_filtered ("%d %s  ", tp->num, target_pid_to_str (tp->pid));
+#ifdef HPUXHPPA
+      printf_filtered ("%d %s", tp->num, target_tid_to_str (tp->ptid));
+#else
+      printf_filtered ("%d %s", tp->num, target_pid_to_str (tp->ptid));
+#endif
+
+      extra_info = target_extra_thread_info (tp);
+      if (extra_info)
+	printf_filtered (" (%s)", extra_info);
+      puts_filtered ("  ");
 
-      switch_to_thread (tp->pid);
+      switch_to_thread (tp->ptid);
+      if (selected_frame)
+	print_only_stack_frame (selected_frame, -1, 0);
+      else
+	printf_filtered ("[No stack.]\n");
+    }
+
+  switch_to_thread (current_ptid);
+
+  /* Code below copied from "up_silently_base" in "stack.c".
+   * It restores the frame set by the user before the "info threads"
+   * command.  We have finished the info-threads display by switching
+   * back to the current thread.  That switch has put us at the top
+   * of the stack (leaf frame).
+   */
+  counter = saved_frame_level;
+  cur_frame = find_relative_frame (selected_frame, &counter);
+  if (counter != 0)
+    {
+      /* Ooops, can't restore, tell user where we are. */
+      warning ("Couldn't restore frame in current thread, at frame 0");
       print_stack_frame (selected_frame, -1, 0);
     }
+  else
+    {
+      select_frame (cur_frame, saved_frame_level);
+    }
 
-  switch_to_thread (current_pid);
+  /* re-show current frame. */
+  show_stack_frame (cur_frame);
 }
 
 /* Switch from one thread to another. */
 
 static void
-switch_to_thread (pid)
-     int pid;
+switch_to_thread (ptid_t ptid)
 {
-  if (pid == inferior_pid)
+  if (ptid_equal (ptid, inferior_ptid))
     return;
 
-  inferior_pid = pid;
+  inferior_ptid = ptid;
   flush_cached_frames ();
   registers_changed ();
-  stop_pc = read_pc();
+  stop_pc = read_pc ();
   select_frame (get_current_frame (), 0);
 }
 
 static void
-restore_current_thread (pid)
-     int pid;
+restore_current_thread (ptid_t ptid)
 {
-  if (pid != inferior_pid)
-    switch_to_thread (pid);
+  if (! ptid_equal (ptid, inferior_ptid))
+    {
+      switch_to_thread (ptid);
+      print_stack_frame (get_current_frame (), 0, -1);
+    }
+}
+
+struct current_thread_cleanup
+{
+  ptid_t inferior_ptid;
+};
+
+static void
+do_restore_current_thread_cleanup (void *arg)
+{
+  struct current_thread_cleanup *old = arg;
+  restore_current_thread (old->inferior_ptid);
+  xfree (old);
+}
+
+static struct cleanup *
+make_cleanup_restore_current_thread (ptid_t inferior_ptid)
+{
+  struct current_thread_cleanup *old
+    = xmalloc (sizeof (struct current_thread_cleanup));
+  old->inferior_ptid = inferior_ptid;
+  return make_cleanup (do_restore_current_thread_cleanup, old);
 }
 
 /* Apply a GDB command to a list of threads.  List syntax is a whitespace
    seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
    of two numbers seperated by a hyphen.  Examples:
 
-	thread apply 1 2 7 4 backtrace	Apply backtrace cmd to threads 1,2,7,4
-	thread apply 2-7 9 p foo(1)	Apply p foo(1) cmd to threads 2->7 & 9
-	thread apply all p x/i $pc	Apply x/i $pc cmd to all threads
-*/
+   thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
+   thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
+   thread apply all p x/i $pc   Apply x/i $pc cmd to all threads
+ */
 
 static void
-thread_apply_all_command (cmd, from_tty)
-     char *cmd;
-     int from_tty;
+thread_apply_all_command (char *cmd, int from_tty)
 {
   struct thread_info *tp;
   struct cleanup *old_chain;
+  struct cleanup *saved_cmd_cleanup_chain;
+  char *saved_cmd;
 
   if (cmd == NULL || *cmd == '\000')
     error ("Please specify a command following the thread ID list");
 
-  old_chain = make_cleanup (restore_current_thread, inferior_pid);
+  old_chain = make_cleanup_restore_current_thread (inferior_ptid);
 
+  /* It is safe to update the thread list now, before
+     traversing it for "thread apply all".  MVS */
+  target_find_new_threads ();
+
+  /* Save a copy of the command in case it is clobbered by
+     execute_command */
+  saved_cmd = xstrdup (cmd);
+  saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
   for (tp = thread_list; tp; tp = tp->next)
     if (thread_alive (tp))
       {
-	switch_to_thread (tp->pid);
+	switch_to_thread (tp->ptid);
+#ifdef HPUXHPPA
+	printf_filtered ("\nThread %d (%s):\n",
+			 tp->num,
+			 target_tid_to_str (inferior_ptid));
+#else
 	printf_filtered ("\nThread %d (%s):\n", tp->num,
-			 target_pid_to_str (inferior_pid));
+			 target_pid_to_str (inferior_ptid));
+#endif
 	execute_command (cmd, from_tty);
+	strcpy (cmd, saved_cmd); /* Restore exact command used previously */
       }
+
+  do_cleanups (saved_cmd_cleanup_chain);
+  do_cleanups (old_chain);
 }
 
 static void
-thread_apply_command (tidlist, from_tty)
-     char *tidlist;
-     int from_tty;
+thread_apply_command (char *tidlist, int from_tty)
 {
   char *cmd;
   char *p;
   struct cleanup *old_chain;
+  struct cleanup *saved_cmd_cleanup_chain;
+  char *saved_cmd;
 
   if (tidlist == NULL || *tidlist == '\000')
     error ("Please specify a thread ID list");
 
-  for (cmd = tidlist; *cmd != '\000' && !isalpha(*cmd); cmd++);
+  for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);
 
   if (*cmd == '\000')
     error ("Please specify a command following the thread ID list");
 
-  old_chain = make_cleanup (restore_current_thread, inferior_pid);
+  old_chain = make_cleanup_restore_current_thread (inferior_ptid);
 
+  /* Save a copy of the command in case it is clobbered by
+     execute_command */
+  saved_cmd = xstrdup (cmd);
+  saved_cmd_cleanup_chain = make_cleanup (xfree, (void *) saved_cmd);
   while (tidlist < cmd)
     {
       struct thread_info *tp;
@@ -428,7 +618,7 @@ thread_apply_command (tidlist, from_tty)
 
       if (*tidlist == '-')	/* Got a range of IDs? */
 	{
-	  tidlist++;	/* Skip the - */
+	  tidlist++;		/* Skip the - */
 	  end = strtol (tidlist, &p, 10);
 	  if (p == tidlist)
 	    error ("Error parsing %s", tidlist);
@@ -450,55 +640,98 @@ thread_apply_command (tidlist, from_tty)
 	    warning ("Thread %d has terminated.", start);
 	  else
 	    {
-	      switch_to_thread (tp->pid);
+	      switch_to_thread (tp->ptid);
+#ifdef HPUXHPPA
 	      printf_filtered ("\nThread %d (%s):\n", tp->num,
-			       target_pid_to_str (inferior_pid));
+			       target_tid_to_str (inferior_ptid));
+#else
+	      printf_filtered ("\nThread %d (%s):\n", tp->num,
+			       target_pid_to_str (inferior_ptid));
+#endif
 	      execute_command (cmd, from_tty);
+	      strcpy (cmd, saved_cmd);	/* Restore exact command used previously */
 	    }
 	}
     }
+
+  do_cleanups (saved_cmd_cleanup_chain);
+  do_cleanups (old_chain);
 }
 
 /* Switch to the specified thread.  Will dispatch off to thread_apply_command
    if prefix of arg is `apply'.  */
 
 static void
-thread_command (tidstr, from_tty)
-     char *tidstr;
-     int from_tty;
+thread_command (char *tidstr, int from_tty)
+{
+  if (!tidstr)
+    {
+      /* Don't generate an error, just say which thread is current. */
+      if (target_has_stack)
+	printf_filtered ("[Current thread is %d (%s)]\n",
+			 pid_to_thread_id (inferior_ptid),
+#if defined(HPUXHPPA)
+			 target_tid_to_str (inferior_ptid)
+#else
+			 target_pid_to_str (inferior_ptid)
+#endif
+	  );
+      else
+	error ("No stack.");
+      return;
+    }
+
+  gdb_thread_select (uiout, tidstr);
+}
+
+static int
+do_captured_thread_select (struct ui_out *uiout,
+			   void *tidstr)
 {
   int num;
   struct thread_info *tp;
 
-  if (!tidstr)
-    error ("Please specify a thread ID.  Use the \"info threads\" command to\n\
-see the IDs of currently known threads.");
-
-  num = atoi (tidstr);
+  num = value_as_long (parse_and_eval (tidstr));
 
   tp = find_thread_id (num);
 
   if (!tp)
-    error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
-see the IDs of currently known threads.", num);
+    error ("Thread ID %d not known.", num);
 
   if (!thread_alive (tp))
     error ("Thread ID %d has terminated.\n", num);
 
-  switch_to_thread (tp->pid);
+  switch_to_thread (tp->ptid);
+
+  ui_out_text (uiout, "[Switching to thread ");
+  ui_out_field_int (uiout, "new-thread-id", pid_to_thread_id (inferior_ptid));
+  ui_out_text (uiout, " (");
+#if defined(HPUXHPPA)
+  ui_out_text (uiout, target_tid_to_str (inferior_ptid));
+#else
+  ui_out_text (uiout, target_pid_to_str (inferior_ptid));
+#endif
+  ui_out_text (uiout, ")]");
 
-  printf_filtered ("[Switching to %s]\n", target_pid_to_str (inferior_pid));
-  print_stack_frame (selected_frame, selected_frame_level, 1);
+  print_stack_frame (selected_frame, frame_relative_level (selected_frame), 1);
+  return GDB_RC_OK;
+}
+
+enum gdb_rc
+gdb_thread_select (struct ui_out *uiout,
+		   char *tidstr)
+{
+  return catch_exceptions (uiout, do_captured_thread_select, tidstr,
+			   NULL, RETURN_MASK_ALL);
 }
 
 /* Commands with a prefix of `thread'.  */
 struct cmd_list_element *thread_cmd_list = NULL;
 
 void
-_initialize_thread ()
+_initialize_thread (void)
 {
   static struct cmd_list_element *thread_apply_list = NULL;
-  extern struct cmd_list_element *cmdlist;
 
   add_info ("threads", info_threads_command,
 	    "IDs of currently known threads.");
@@ -516,5 +749,6 @@ The new thread ID must be currently known.", &thread_cmd_list, "thread ", 1,
 	   "Apply a command to all threads.",
 	   &thread_apply_list);
 
-  add_com_alias ("t", "thread", class_run, 1);
+  if (!xdb_commands)
+    add_com_alias ("t", "thread", class_run, 1);
 }