gdb/mi: New commands to catch C++ exceptions

Adds some MI commands to catch C++ exceptions.  The new commands are
-catch-throw, -catch-rethrow, and -catch-catch, these all correspond
to the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.

Each MI command takes two optional arguments, '-t' has the effect of
calling 'tcatch' instead of 'catch', for example:

   (gdb)
   -catch-throw -t

Is the same as:

   (gdb) tcatch throw

There is also a '-r REGEXP' argument that can supply a regexp to match
against the exception type, so:

   (gdb)
   -catch-catch -r PATTERN

Is the same as:

   (gdb) catch catch PATTERN

The change in print_mention_exception_catchpoint might seem a little
strange; changing the output from using ui_out::field_int and
ui_out::text to using  ui_out::message.

The print_mention_exception_catchpoint is used as the 'print_mention'
method for the exception catchpoint breakpoint object.  Most of the
other 'print_mention' methods (see breakpoint.c) use either
printf_filtered, of ui_out::message.  Using field_int was causing an
unexpected field to be added to the MI output.  Here's the output
without the change in print_mention_exception_catchpoint:

    (gdb)
    -catch-throw
    ^done,bkptno="1",bkpt={number="1",type="breakpoint",disp="keep",
                           enabled="y",addr="0x00000000004006c0",
                           what="exception throw",catch-type="throw",
                           thread-groups=["i1"],times="0"}

Notice the breakpoint number appears in both the 'bkptno' field, and
the 'number' field within the 'bkpt' tuple.  Here's the output with
the change in print_mention_exception_catchpoint:

    (gdb)
    -catch-throw
    ^done,bkpt={number="1",type="breakpoint",disp="keep",
                enabled="y",addr="0x00000000004006c0",
                what="exception throw",catch-type="throw",
                thread-groups=["i1"],times="0"}

gdb/ChangeLog:

	* NEWS: Mention new MI commands.
	* break-catch-throw.c (enum exception_event_kind): Move to
	breakpoint.h.
	(print_mention_exception_catchpoint): Output text as a single
	message.
	(catch_exception_command_1): Rename to...
	(catch_exception_event): ...this, make non-static, update header
	command, and change some parameter types.
	(catch_catch_command): Update for changes to
	catch_exception_command_1.
	(catch_throw_command): Likewise.
	(catch_rethrow_command): Likewise.
	* breakpoint.c (enum exception_event_kind): Delete.
	* breakpoint.h (enum exception_event_kind): Moved here from
	break-catch-throw.c.
	(catch_exception_event): Declare.
	* mi/mi-cmd-catch.c (mi_cmd_catch_exception_event): New function.
	(mi_cmd_catch_throw): New function.
	(mi_cmd_catch_rethrow): New function.
	(mi_cmd_catch_catch): New function.
	* mi/mi-cmds.c (mi_cmds): Add 'catch-throw', 'catch-rethrow', and
	'catch-catch' entries.
	* mi/mi-cmds.h (mi_cmd_catch_throw): Declare.
	(mi_cmd_catch_rethrow): Declare.
	(mi_cmd_catch_catch): Declare.

gdb/doc/ChangeLog:

	* gdb.texinfo (GDB/MI Catchpoint Commands): Add menu entry to new
	node.
	(C++ Exception GDB/MI Catchpoint Commands): New node to describe
	new MI commands.

gdb/testsuite/ChangeLog:

	* gdb.mi/mi-catch-cpp-exceptions.cc: New file.
	* gdb.mi/mi-catch-cpp-exceptions.exp: New file.
	* lib/mi-support.exp (mi_expect_stop): Handle 'exception-caught'
	as a stop reason.

3 files changed, 80 insertions, 0 deletions

diff --git a/gdb/mi/mi-cmd-catch.c b/gdb/mi/mi-cmd-catch.c
index 87929c4..a044fe4 100644
--- a/gdb/mi/mi-cmd-catch.c
+++ b/gdb/mi/mi-cmd-catch.c
@@ -288,3 +288,74 @@ mi_cmd_catch_unload (const char *cmd, char *argv[], int argc)
   mi_catch_load_unload (0, argv, argc);
 }
 
+/* Core handler for -catch-throw, -catch-rethrow, and -catch-catch
+   commands.  The argument handling for all of these is identical, we just
+   pass KIND through to GDB's core to select the correct event type.  */
+
+static void
+mi_cmd_catch_exception_event (enum exception_event_kind kind,
+			      const char *cmd, char *argv[], int argc)
+{
+  char *regex = NULL;
+  bool temp = false;
+  int oind = 0;
+  char *oarg;
+  enum opt
+    {
+      OPT_TEMP,
+      OPT_REGEX,
+    };
+  static const struct mi_opt opts[] =
+    {
+      { "t", OPT_TEMP, 0 },
+      { "r", OPT_REGEX, 1 },
+      { 0, 0, 0 }
+    };
+
+  for (;;)
+    {
+      int opt = mi_getopt (cmd, argc, argv, opts,
+                           &oind, &oarg);
+
+      if (opt < 0)
+        break;
+
+      switch ((enum opt) opt)
+        {
+        case OPT_TEMP:
+          temp = true;
+          break;
+        case OPT_REGEX:
+	  regex = oarg;
+          break;
+        }
+    }
+
+  scoped_restore restore_breakpoint_reporting = setup_breakpoint_reporting ();
+  catch_exception_event (kind, regex, temp, 0 /* from_tty */);
+}
+
+/* Handler for -catch-throw.  */
+
+void
+mi_cmd_catch_throw (const char *cmd, char *argv[], int argc)
+{
+  mi_cmd_catch_exception_event (EX_EVENT_THROW, cmd, argv, argc);
+}
+
+/* Handler for -catch-rethrow.  */
+
+void
+mi_cmd_catch_rethrow (const char *cmd, char *argv[], int argc)
+{
+  mi_cmd_catch_exception_event (EX_EVENT_RETHROW, cmd, argv, argc);
+}
+
+/* Handler for -catch-catch.  */
+
+void
+mi_cmd_catch_catch (const char *cmd, char *argv[], int argc)
+{
+  mi_cmd_catch_exception_event (EX_EVENT_CATCH, cmd, argv, argc);
+}
+
diff --git a/gdb/mi/mi-cmds.c b/gdb/mi/mi-cmds.c
index bbc0e2b..37eab01 100644
--- a/gdb/mi/mi-cmds.c
+++ b/gdb/mi/mi-cmds.c
@@ -75,6 +75,12 @@ static struct mi_cmd mi_cmds[] =
                    &mi_suppress_notification.breakpoint),
   DEF_MI_CMD_MI_1 ("catch-unload", mi_cmd_catch_unload,
                    &mi_suppress_notification.breakpoint),
+  DEF_MI_CMD_MI_1 ("catch-throw", mi_cmd_catch_throw,
+                   &mi_suppress_notification.breakpoint),
+  DEF_MI_CMD_MI_1 ("catch-rethrow", mi_cmd_catch_rethrow,
+                   &mi_suppress_notification.breakpoint),
+  DEF_MI_CMD_MI_1 ("catch-catch", mi_cmd_catch_catch,
+                   &mi_suppress_notification.breakpoint),
   DEF_MI_CMD_MI ("complete", mi_cmd_complete),
   DEF_MI_CMD_MI ("data-disassemble", mi_cmd_disassemble),
   DEF_MI_CMD_MI ("data-evaluate-expression", mi_cmd_data_evaluate_expression),
diff --git a/gdb/mi/mi-cmds.h b/gdb/mi/mi-cmds.h
index 58aa2d6..91ce4cd 100644
--- a/gdb/mi/mi-cmds.h
+++ b/gdb/mi/mi-cmds.h
@@ -44,6 +44,9 @@ extern mi_cmd_argv_ftype mi_cmd_catch_exception;
 extern mi_cmd_argv_ftype mi_cmd_catch_handlers;
 extern mi_cmd_argv_ftype mi_cmd_catch_load;
 extern mi_cmd_argv_ftype mi_cmd_catch_unload;
+extern mi_cmd_argv_ftype mi_cmd_catch_throw;
+extern mi_cmd_argv_ftype mi_cmd_catch_rethrow;
+extern mi_cmd_argv_ftype mi_cmd_catch_catch;
 extern mi_cmd_argv_ftype mi_cmd_disassemble;
 extern mi_cmd_argv_ftype mi_cmd_data_evaluate_expression;
 extern mi_cmd_argv_ftype mi_cmd_data_list_register_names;