C++-fy struct interp/cli_interp/tui_interp/mi_interp

- The interp->data field disappears, since we can put data in the
  interpreter directly now.  The "init" method remains in place, but
  it now returns void.

- A few places check if the interpreter method is NULL before calling
  it, and also check whether the method returns true/false.  For some
  of those methods, all current implementations always return true.
  In those cases, this commit makes the C++-fied method return void
  instead and cleans up the callers.

Tested on x86_64 Fedora 23.

gdb/ChangeLog:
2017-02-03  Pedro Alves  <palves@redhat.com>

	* cli/cli-interp.c (cli_interp_base::cli_interp_base)
	(cli_interp_base::~cli_interp_base): New.
	(cli_interp): New struct.
	(as_cli_interp): Cast the interp itself to cli_interp.
	(cli_interpreter_pre_command_loop): Rename to ...
	(cli_interp_base::pre_command_loop): ... this.  Remove 'self'
	parameter.
	(cli_interpreter_init): Rename to ...
	(cli_interp::init): ... this.  Remove 'self' parameter.  Use
	boolean.  Make extern.
	(cli_interpreter_resume): Rename to ...
	(cli_interp::resume): ... this.  Remove 'data' parameter.  Make
	extern.
	(cli_interpreter_suspend): Rename to ...
	(cli_interp::suspend): ... this.  Remove 'data' parameter.  Make
	extern.
	(cli_interpreter_exec): Rename to ...
	(cli_interp::exec): ... this.  Remove 'data' parameter.  Make
	extern.
	(cli_interpreter_supports_command_editing): Rename to ...
	(cli_interp_base::supports_command_editing): ... this.  Remove
	'interp' parameter.  Make extern.
	(cli_ui_out): Rename to ...
	(cli_interp::interp_ui_out): ... this.  Remove 'interp' parameter.
	Make extern.
	(cli_set_logging): Rename to ...
	(cli_interp_base::set_logging): ... this.  Remove 'interp'
	parameter.  Make extern.
	(cli_interp_procs): Delete.
	(cli_interp_factory): Adjust to use "new".
	* cli/cli-interp.h: Include "interps.h".
	(struct cli_interp_base): New struct.
	* interps.c (struct interp): Delete.  Fields moved to interps.h.
	(interp_new): Delete.
	(interp::interp, interp::~interp): New.
	(interp_set): Use bool, and return void.  Assume the interpreter
	has suspend, init and resume methods, and that the all return
	void.
	(set_top_level_interpreter): interp_set returns void.
	(interp_ui_out): Adapt.
	(current_interp_set_logging): Adapt.
	(interp_data): Delete.
	(interp_pre_command_loop, interp_supports_command_editing): Adapt.
	(interp_exec): Adapt.
	(top_level_interpreter_data): Delete.
	* interps.h (interp_init_ftype, interp_resume_ftype)
	(interp_suspend_ftype, interp_exec_ftype)
	(interp_pre_command_loop_ftype, interp_ui_out_ftype): Delete.
	(class interp): New.
	(interp_new): Delete.
	(interp_set): Now returns void.  Use bool.
	(interp_data, top_level_interpreter_data): Delete.
	* mi/mi-common.h: Include interps.h.
	(class mi_interp): Inherit from interp.  Define a ctor.  Declare
	init, resume, suspect, exec, interp_ui_out, set_logging and
	pre_command_loop methods.
	* mi/mi-interp.c (as_mi_interp): Cast the interp itself.
	(mi_interpreter_init): Rename to ...
	(mi_interp::init): ... this.  Remove the 'interp' parameter, use
	bool, return void and make extern.  Adjust.
	(mi_interpreter_resume): ... Rename to ...
	(mi_interp::resume): ... this.  Remove the 'data' parameter,
	return void and make extern.  Adjust.
	(mi_interpreter_suspend): ... Rename to ...
	(mi_interp::suspend): ... this.  Remove the 'data' parameter,
	return void and make extern.  Adjust.
	(mi_interpreter_exec): ... Rename to ...
	(mi_interp::exec): ... this.  Remove the 'data' parameter and make
	extern.  Adjust.
	(mi_interpreter_pre_command_loop): ... Rename to ...
	(mi_interp::pre_command_loop): ... this.  Remove the 'self'
	parameter and make extern.
	(mi_on_normal_stop_1): Adjust.
	(mi_ui_out): Rename to ...
	(mi_interp::interp_ui_out): ... this.  Remove the 'interp'
	parameter and make extern.  Adjust.
	(mi_set_logging): Rename to ...
	(mi_interp::set_logging): ... this.  Remove the 'interp'
	parameter and make extern.  Adjust.
	(mi_interp_procs): Delete.
	(mi_interp_factory): Adjust to use 'new'.
	* mi/mi-main.c (mi_cmd_gdb_exit, captured_mi_execute_command)
	(mi_print_exception, mi_execute_command, mi_load_progress):
	Adjust.
	* tui/tui-interp.c (tui_interp): New class.
	(as_tui_interp): Return a tui_interp pointer.
	(tui_on_normal_stop, tui_on_signal_received)
	(tui_on_end_stepping_range, tui_on_signal_exited, tui_on_exited)
	(tui_on_no_history, tui_on_user_selected_context_changed): Adjust
	to use interp::interp_ui_out.
	(tui_init): Rename to ...
	(tui_interp::init): ... this.  Remove the 'self' parameter, use
	bool, return void and make extern.  Adjust.
	(tui_resume): Rename to ...
	(tui_interp::resume): ... this.  Remove the 'data' parameter,
	return void and make extern.  Adjust.
	(tui_suspend): Rename to ...
	(tui_interp::suspend): ... this.  Remove the 'data' parameter,
	return void and make extern.  Adjust.
	(tui_ui_out): Rename to ...
	(tui_interp::interp_ui_out): ... this.  Remove the 'self'
	parameter, and make extern.  Adjust.
	(tui_exec): Rename to ...
	(tui_interp::exec): ... this.  Remove the 'data' parameter and
	make extern.
	(tui_interp_procs): Delete.
	(tui_interp_factory): Use "new".

3 files changed, 46 insertions, 56 deletions

diff --git a/gdb/mi/mi-common.h b/gdb/mi/mi-common.h
index 9ee38b0..8fa9c9d 100644
--- a/gdb/mi/mi-common.h
+++ b/gdb/mi/mi-common.h
@@ -19,6 +19,8 @@
 #ifndef MI_COMMON_H
 #define MI_COMMON_H
 
+#include "interps.h"
+
 struct mi_console_file;
 
 /* Represents the reason why GDB is sending an asynchronous command to
@@ -50,8 +52,23 @@ enum async_reply_reason
 
 const char *async_reason_lookup (enum async_reply_reason reason);
 
-struct mi_interp
+/* An MI interpreter.  */
+
+class mi_interp final : public interp
 {
+public:
+  mi_interp (const char *name)
+    : interp (name)
+  {}
+
+  void init (bool top_level) override;
+  void resume () override;
+  void suspend () override;
+  gdb_exception exec (const char *command_str) override;
+  ui_out *interp_ui_out () override;
+  void set_logging (ui_file_up logfile, bool logging_redirect) override;
+  void pre_command_loop () override;
+
   /* MI's output channels */
   mi_console_file *out;
   mi_console_file *err;
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index aa76989..86340e4 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -108,14 +108,14 @@ static struct mi_interp *
 as_mi_interp (struct interp *interp)
 {
   if (interp_ui_out (interp)->is_mi_like_p ())
-    return (struct mi_interp *) interp_data (interp);
+    return (struct mi_interp *) interp;
   return NULL;
 }
 
-static void *
-mi_interpreter_init (struct interp *interp, int top_level)
+void
+mi_interp::init (bool top_level)
 {
-  struct mi_interp *mi = XNEW (struct mi_interp);
+  mi_interp *mi = this;
   const char *name;
   int mi_version;
 
@@ -132,7 +132,7 @@ mi_interpreter_init (struct interp *interp, int top_level)
   mi->targ = new mi_console_file (mi->raw_stdout, "@", '"');
   mi->event_channel = new mi_console_file (mi->raw_stdout, "=", 0);
 
-  name = interp_name (interp);
+  name = interp_name (this);
   /* INTERP_MI selects the most recent released version.  "mi2" was
      released as part of GDB 6.0.  */
   if (strcmp (name, INTERP_MI) == 0)
@@ -157,14 +157,12 @@ mi_interpreter_init (struct interp *interp, int top_level)
 	 up-front.  */
       iterate_over_inferiors (report_initial_inferior, mi);
     }
-
-  return mi;
 }
 
-static int
-mi_interpreter_resume (void *data)
+void
+mi_interp::resume ()
 {
-  struct mi_interp *mi = (struct mi_interp *) data;
+  struct mi_interp *mi = this;
   struct ui *ui = current_ui;
 
   /* As per hack note in mi_interpreter_init, swap in the output
@@ -188,19 +186,16 @@ mi_interpreter_resume (void *data)
   clear_interpreter_hooks ();
 
   deprecated_show_load_progress = mi_load_progress;
-
-  return 1;
 }
 
-static int
-mi_interpreter_suspend (void *data)
+void
+mi_interp::suspend ()
 {
   gdb_disable_readline ();
-  return 1;
 }
 
-static struct gdb_exception
-mi_interpreter_exec (void *data, const char *command)
+gdb_exception
+mi_interp::exec (const char *command)
 {
   mi_execute_command_wrapper (command);
   return exception_none;
@@ -327,10 +322,10 @@ mi_execute_command_input_handler (char *cmd)
     display_mi_prompt (mi);
 }
 
-static void
-mi_interpreter_pre_command_loop (struct interp *self)
+void
+mi_interp::pre_command_loop ()
 {
-  struct mi_interp *mi = (struct mi_interp *) interp_data (self);
+  struct mi_interp *mi = this;
 
   /* Turn off 8 bit strings in quoted output.  Any character with the
      high bit set is printed using C's octal format.  */
@@ -658,7 +653,7 @@ mi_on_normal_stop_1 (struct bpstats *bs, int print_frame)
      using cli interpreter, be sure to use MI uiout for output,
      not the current one.  */
   struct ui_out *mi_uiout = interp_ui_out (top_level_interpreter ());
-  struct mi_interp *mi = (struct mi_interp *) top_level_interpreter_data ();
+  struct mi_interp *mi = (struct mi_interp *) top_level_interpreter ();
 
   if (print_frame)
     {
@@ -1362,24 +1357,19 @@ report_initial_inferior (struct inferior *inf, void *closure)
   return 0;
 }
 
-static struct ui_out *
-mi_ui_out (struct interp *interp)
+ui_out *
+mi_interp::interp_ui_out ()
 {
-  struct mi_interp *mi = (struct mi_interp *) interp_data (interp);
-
-  return mi->mi_uiout;
+  return this->mi_uiout;
 }
 
 /* Do MI-specific logging actions; save raw_stdout, and change all
    the consoles to use the supplied ui-file(s).  */
 
-static void
-mi_set_logging (struct interp *interp,
-	        ui_file_up logfile, bool logging_redirect)
+void
+mi_interp::set_logging (ui_file_up logfile, bool logging_redirect)
 {
-  struct mi_interp *mi = (struct mi_interp *) interp_data (interp);
-
-  gdb_assert (mi != NULL);
+  struct mi_interp *mi = this;
 
   if (logfile != NULL)
     {
@@ -1403,25 +1393,12 @@ mi_set_logging (struct interp *interp,
   mi->event_channel->set_raw (mi->raw_stdout);
 }
 
-/* The MI interpreter's vtable.  */
-
-static const struct interp_procs mi_interp_procs =
-{
-  mi_interpreter_init,		/* init_proc */
-  mi_interpreter_resume,	/* resume_proc */
-  mi_interpreter_suspend,	/* suspend_proc */
-  mi_interpreter_exec,		/* exec_proc */
-  mi_ui_out, 			/* ui_out_proc */
-  mi_set_logging,		/* set_logging_proc */
-  mi_interpreter_pre_command_loop /* pre_command_loop_proc */
-};
-
 /* Factory for MI interpreters.  */
 
 static struct interp *
 mi_interp_factory (const char *name)
 {
-  return interp_new (name, &mi_interp_procs, NULL);
+  return new mi_interp (name);
 }
 
 extern initialize_file_ftype _initialize_mi_interp; /* -Wmissing-prototypes */
diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index b249f2d..cf4e45a 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -147,8 +147,7 @@ static void print_diff (struct ui_file *file, struct mi_timestamp *start,
 void
 mi_cmd_gdb_exit (char *command, char **argv, int argc)
 {
-  struct mi_interp *mi
-    = (struct mi_interp *) interp_data (current_interpreter ());
+  struct mi_interp *mi = (struct mi_interp *) current_interpreter ();
 
   /* We have to print everything right here because we never return.  */
   if (current_token)
@@ -1974,7 +1973,7 @@ mi_cmd_remove_inferior (char *command, char **argv, int argc)
 static void
 captured_mi_execute_command (struct ui_out *uiout, struct mi_parse *context)
 {
-  struct mi_interp *mi = (struct mi_interp *) interp_data (command_interp ());
+  struct mi_interp *mi = (struct mi_interp *) command_interp ();
   struct cleanup *cleanup;
 
   if (do_timings)
@@ -2066,8 +2065,7 @@ captured_mi_execute_command (struct ui_out *uiout, struct mi_parse *context)
 static void
 mi_print_exception (const char *token, struct gdb_exception exception)
 {
-  struct mi_interp *mi
-    = (struct mi_interp *) interp_data (current_interpreter ());
+  struct mi_interp *mi = (struct mi_interp *) current_interpreter ();
 
   fputs_unfiltered (token, mi->raw_stdout);
   fputs_unfiltered ("^error,msg=\"", mi->raw_stdout);
@@ -2190,8 +2188,7 @@ mi_execute_command (const char *cmd, int from_tty)
 	     again.  */
 	  && !command_notifies_uscc_observer (command))
 	{
-	  struct mi_interp *mi
-	    = (struct mi_interp *) top_level_interpreter_data ();
+	  struct mi_interp *mi = (struct mi_interp *) top_level_interpreter ();
 	  int report_change = 0;
 
 	  if (command->thread == -1)
@@ -2378,8 +2375,7 @@ mi_load_progress (const char *section_name,
   int new_section;
   struct ui_out *saved_uiout;
   struct ui_out *uiout;
-  struct mi_interp *mi
-    = (struct mi_interp *) interp_data (current_interpreter ());
+  struct mi_interp *mi = (struct mi_interp *) current_interpreter ();
 
   /* This function is called through deprecated_show_load_progress
      which means uiout may not be correct.  Fix it for the duration