* defs.h (quit_flag): Don't declare.

(clear_quit_flag, check_quit_flag, set_quit_flag): Declare.
	(QUIT): Use new functions.
	* event-top.c (command_handler): Use clear_quit_flag.
	(handle_sigint): Use set_quit_flag.
	(async_request_quit): Use check_quit_flag.  Don't check
	immediate_quit.
	* exceptions.c (throw_exception): Use clear_quit_flag.
	* main.c (captured_main): Use clear_quit_flag.
	* python/python.c (clear_quit_flag, set_quit_flag)
	(check_quit_flag): New functions.
	* remote-sim.c (gdb_os_poll_quit): Use check_quit_flag,
	clear_quit_flag.
	* remote.c (remote_wait_as): Use check_quit_flag,
	clear_quit_flag.
	(remote_start_remote): Call QUIT.
	* symfile.c (load_progress): Use check_quit_flag.
	* top.c (command_loop): Use clear_quit_flag.
	(command_line_input): Call QUIT.
	* utils.c (quit_flag): Conditionally define.
	(clear_quit_flag, check_quit_flag, set_quit_flag): New
	functions.
	(prompt_for_continue): Call QUIT.  Use quit, not
	async_request_quit.
	* remote-mips.c (mips_expect_timeout): Call QUIT.
	* monitor.c (monitor_expect): Call QUIT.

gdb/ChangeLog

@@ -1,3 +1,32 @@
+2012-08-22  Tom Tromey  <tromey@redhat.com>
+
+	* defs.h (quit_flag): Don't declare.
+	(clear_quit_flag, check_quit_flag, set_quit_flag): Declare.
+	(QUIT): Use new functions.
+	* event-top.c (command_handler): Use clear_quit_flag.
+	(handle_sigint): Use set_quit_flag.
+	(async_request_quit): Use check_quit_flag.  Don't check
+	immediate_quit.
+	* exceptions.c (throw_exception): Use clear_quit_flag.
+	* main.c (captured_main): Use clear_quit_flag.
+	* python/python.c (clear_quit_flag, set_quit_flag)
+	(check_quit_flag): New functions.
+	* remote-sim.c (gdb_os_poll_quit): Use check_quit_flag,
+	clear_quit_flag.
+	* remote.c (remote_wait_as): Use check_quit_flag,
+	clear_quit_flag.
+	(remote_start_remote): Call QUIT.
+	* symfile.c (load_progress): Use check_quit_flag.
+	* top.c (command_loop): Use clear_quit_flag.
+	(command_line_input): Call QUIT.
+	* utils.c (quit_flag): Conditionally define.
+	(clear_quit_flag, check_quit_flag, set_quit_flag): New
+	functions.
+	(prompt_for_continue): Call QUIT.  Use quit, not
+	async_request_quit.
+	* remote-mips.c (mips_expect_timeout): Call QUIT.
+	* monitor.c (monitor_expect): Call QUIT.
+
 2012-08-22  Tom Tromey  <tromey@redhat.com>
 
 	* event-top.c (sigwinch_token, handle_sigwinch): Remove.

gdb/defs.h

@@ -171,7 +171,27 @@ extern char *python_libdir;
 /* Search path for separate debug files.  */
 extern char *debug_file_directory;
 
-extern int quit_flag;
+/* GDB has two methods for handling SIGINT.  When immediate_quit is
+   nonzero, a SIGINT results in an immediate longjmp out of the signal
+   handler.  Otherwise, SIGINT simply sets a flag; code that might
+   take a long time, and which ought to be interruptible, checks this
+   flag using the QUIT macro.
+   
+   If GDB is built with Python support, it uses Python's low-level
+   interface to implement the flag.  This approach makes it possible
+   for Python and GDB SIGINT handling to coexist seamlessly.
+
+   If GDB is built without Python, it instead uses its traditional
+   variables.  */
+
+/* Clear the quit flag.  */
+extern void clear_quit_flag (void);
+/* Evaluate to non-zero if the quit flag is set, zero otherwise.  This
+   will clear the quit flag as a side effect.  */
+extern int check_quit_flag (void);
+/* Set the quit flag.  */
+extern void set_quit_flag (void);
+
 extern int immediate_quit;
 
 extern void quit (void);
@@ -184,7 +204,7 @@ extern void quit (void);
    needed.  */
 
 #define QUIT { \
-  if (quit_flag) quit (); \
+  if (check_quit_flag ()) quit (); \
   if (deprecated_interactive_hook) deprecated_interactive_hook (); \
 }
 

gdb/event-top.c

@@ -409,7 +409,7 @@ command_handler (char *command)
   int stdin_is_tty = ISATTY (stdin);
   struct cleanup *stat_chain;
 
-  quit_flag = 0;
+  clear_quit_flag ();
   if (instream == stdin && stdin_is_tty)
     reinitialize_more_filter ();
 
@@ -788,7 +788,7 @@ handle_sigint (int sig)
      set quit_flag to 1 here.  Then if QUIT is called before we get to
      the event loop, we will unwind as expected.  */
 
-  quit_flag = 1;
+  set_quit_flag ();
 
   /* If immediate_quit is set, we go ahead and process the SIGINT right
      away, even if we usually would defer this to the event loop.  The
@@ -817,10 +817,9 @@ async_request_quit (gdb_client_data arg)
   /* If the quit_flag has gotten reset back to 0 by the time we get
      back here, that means that an exception was thrown to unwind the
      current command before we got back to the event loop.  So there
-     is no reason to call quit again here, unless immediate_quit is
-     set.  */
+     is no reason to call quit again here.  */
 
-  if (quit_flag || immediate_quit)
+  if (check_quit_flag ())
     quit ();
 }
 

gdb/exceptions.c

@@ -221,7 +221,7 @@ exceptions_state_mc_action_iter_1 (void)
 void
 throw_exception (struct gdb_exception exception)
 {
-  quit_flag = 0;
+  clear_quit_flag ();
   immediate_quit = 0;
 
   do_cleanups (all_cleanups ());

gdb/main.c

@@ -331,7 +331,7 @@ captured_main (void *data)
   dirarg = (char **) xmalloc (dirsize * sizeof (*dirarg));
   ndir = 0;
 
-  quit_flag = 0;
+  clear_quit_flag ();
   saved_command_line = (char *) xmalloc (saved_command_line_size);
   saved_command_line[0] = '\0';
   instream = stdin;

gdb/monitor.c

@@ -512,6 +512,7 @@ monitor_expect (char *string, char *buf, int buflen)
     }
 
   immediate_quit++;
+  QUIT;
   while (1)
     {
       if (buf)

gdb/python/python.c

@@ -151,6 +151,31 @@ ensure_python_env (struct gdbarch *gdbarch,
   return make_cleanup (restore_python_env, env);
 }
 
+/* Clear the quit flag.  */
+
+void
+clear_quit_flag (void)
+{
+  /* This clears the flag as a side effect.  */
+  PyOS_InterruptOccurred ();
+}
+
+/* Set the quit flag.  */
+
+void
+set_quit_flag (void)
+{
+  PyErr_SetInterrupt ();
+}
+
+/* Return true if the quit flag has been set, false otherwise.  */
+
+int
+check_quit_flag (void)
+{
+  return PyOS_InterruptOccurred ();
+}
+
 /* A wrapper around PyRun_SimpleFile.  FILE is the Python script to run
    named FILENAME.
 

gdb/remote-mips.c

@@ -588,6 +588,7 @@ mips_expect_timeout (const char *string, int timeout)
     }
 
   immediate_quit++;
+  QUIT;
   while (1)
     {
       int c;

gdb/remote-sim.c

@@ -950,9 +950,9 @@ gdb_os_poll_quit (host_callback *p)
   if (deprecated_ui_loop_hook != NULL)
     deprecated_ui_loop_hook (0);
 
-  if (quit_flag)		/* gdb's idea of quit */
+  if (check_quit_flag ())	/* gdb's idea of quit */
     {
-      quit_flag = 0;		/* we've stolen it */
+      clear_quit_flag ();	/* we've stolen it */
       return 1;
     }
   return 0;

gdb/remote.c

@@ -3271,6 +3271,7 @@ remote_start_remote (int from_tty, struct target_ops *target, int extended_p)
   char *wait_status = NULL;
 
   immediate_quit++;		/* Allow user to interrupt it.  */
+  QUIT;
 
   if (interrupt_on_connect)
     send_interrupt_sequence ();
@@ -5714,9 +5715,9 @@ remote_wait_as (ptid_t ptid, struct target_waitstatus *status, int options)
 	  ofunc = signal (SIGINT, remote_interrupt);
 	  /* If the user hit C-c before this packet, or between packets,
 	     pretend that it was hit right here.  */
-	  if (quit_flag)
+	  if (check_quit_flag ())
 	    {
-	      quit_flag = 0;
+	      clear_quit_flag ();
 	      remote_interrupt (SIGINT);
 	    }
 	}

gdb/symfile.c

@@ -1986,7 +1986,7 @@ load_progress (ULONGEST bytes, void *untyped_arg)
   args->buffer += bytes;
   totals->write_count += 1;
   args->section_sent += bytes;
-  if (quit_flag
+  if (check_quit_flag ()
       || (deprecated_ui_load_progress_hook != NULL
 	  && deprecated_ui_load_progress_hook (args->section_name,
 					       args->section_sent)))

gdb/top.c

@@ -569,7 +569,7 @@ command_loop (void)
       if (window_hook && instream == stdin)
 	(*window_hook) (instream, get_prompt ());
 
-      quit_flag = 0;
+      clear_quit_flag ();
       if (instream == stdin && stdin_is_tty)
 	reinitialize_more_filter ();
       old_chain = make_cleanup (null_cleanup, 0);
@@ -944,6 +944,7 @@ command_line_input (char *prompt_arg, int repeat, char *annotation_suffix)
   /* Control-C quits instantly if typed while in this loop
      since it should not wait until the user types a newline.  */
   immediate_quit++;
+  QUIT;
 #ifdef STOP_SIGNAL
   if (job_control)
     signal (STOP_SIGNAL, handle_stop_sig);

gdb/utils.c

@@ -122,9 +122,11 @@ static int debug_timestamp = 0;
 
 int job_control;
 
+#ifndef HAVE_PYTHON
 /* Nonzero means a quit has been requested.  */
 
 int quit_flag;
+#endif /* HAVE_PYTHON */
 
 /* Nonzero means quit immediately if Control-C is typed now, rather
    than waiting until QUIT is executed.  Be careful in setting this;
@@ -139,6 +141,41 @@ int quit_flag;
 
 int immediate_quit;
 
+#ifndef HAVE_PYTHON
+
+/* Clear the quit flag.  */
+
+void
+clear_quit_flag (void)
+{
+  quit_flag = 0;
+}
+
+/* Set the quit flag.  */
+
+void
+set_quit_flag (void)
+{
+  quit_flag = 1;
+}
+
+/* Return true if the quit flag has been set, false otherwise.  */
+
+int
+check_quit_flag (void)
+{
+  /* This is written in a particular way to avoid races.  */
+  if (quit_flag)
+    {
+      quit_flag = 0;
+      return 1;
+    }
+
+  return 0;
+}
+
+#endif /* HAVE_PYTHON */
+
 /* Nonzero means that strings with character values >0x7F should be printed
    as octal escapes.  Zero means just print the value (e.g. it's an
    international character, and the terminal or window can cope.)  */
@@ -1840,6 +1877,7 @@ prompt_for_continue (void)
   reinitialize_more_filter ();
 
   immediate_quit++;
+  QUIT;
   /* On a real operating system, the user can quit with SIGINT.
      But not on GO32.
 
@@ -1868,7 +1906,7 @@ prompt_for_continue (void)
       while (*p == ' ' || *p == '\t')
 	++p;
       if (p[0] == 'q')
-	async_request_quit (0);
+	quit ();
       xfree (ignore);
     }
   immediate_quit--;