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".

1 files changed, 24 insertions, 103 deletions

diff --git a/gdb/interps.c b/gdb/interps.c
index 06e7ccfc8ab..d31d53b9175 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -72,28 +72,6 @@ get_current_interp_info (void)
   return get_interp_info (current_ui);
 }
 
-struct interp
-{
-  /* This is the name in "-i=" and set interpreter.  */
-  const char *name;
-
-  /* Interpreters are stored in a linked list, this is the next
-     one...  */
-  struct interp *next;
-
-  /* This is a cookie that an instance of the interpreter can use.
-     This is a bit confused right now as the exact initialization
-     sequence for it, and how it relates to the interpreter's uiout
-     object is a bit confused.  */
-  void *data;
-
-  /* Has the init_proc been run?  */
-  int inited;
-
-  const struct interp_procs *procs;
-  int quiet_p;
-};
-
 /* The magic initialization routine for this module.  */
 
 void _initialize_interpreter (void);
@@ -101,25 +79,16 @@ void _initialize_interpreter (void);
 static struct interp *interp_lookup_existing (struct ui *ui,
 					      const char *name);
 
-/* interp_new - This allocates space for a new interpreter,
-   fills the fields from the inputs, and returns a pointer to the
-   interpreter.  */
-struct interp *
-interp_new (const char *name, const struct interp_procs *procs, void *data)
+interp::interp (const char *name)
 {
-  struct interp *new_interp;
-
-  new_interp = XNEW (struct interp);
-
-  new_interp->name = xstrdup (name);
-  new_interp->data = data;
-  new_interp->quiet_p = 0;
-  new_interp->procs = procs;
-  new_interp->inited = 0;
-
-  return new_interp;
+  this->name = xstrdup (name);
+  this->quiet_p = false;
+  this->inited = false;
 }
 
+interp::~interp ()
+{}
+
 /* An interpreter factory.  Maps an interpreter name to the factory
    function that instantiates an interpreter by that name.  */
 
@@ -177,11 +146,7 @@ interp_add (struct ui *ui, struct interp *interp)
 }
 
 /* This sets the current interpreter to be INTERP.  If INTERP has not
-   been initialized, then this will also run the init proc.  If the
-   init proc is successful, return 1, if it fails, set the old
-   interpreter back in place and return 0.  If we can't restore the
-   old interpreter, then raise an internal error, since we are in
-   pretty bad shape at this point.
+   been initialized, then this will also run the init method.
 
    The TOP_LEVEL parameter tells if this new interpreter is
    the top-level one.  The top-level is what is requested
@@ -190,8 +155,9 @@ interp_add (struct ui *ui, struct interp *interp)
    MI is the top-level interpreter, then it will always report
    events such as target stops and new thread creation, even if they
    are caused by CLI commands.  */
-int
-interp_set (struct interp *interp, int top_level)
+
+void
+interp_set (struct interp *interp, bool top_level)
 {
   struct ui_interp_info *ui_interp = get_current_interp_info ();
   struct interp *old_interp = ui_interp->current_interpreter;
@@ -206,12 +172,7 @@ interp_set (struct interp *interp, int top_level)
   if (old_interp != NULL)
     {
       current_uiout->flush ();
-      if (old_interp->procs->suspend_proc
-	  && !old_interp->procs->suspend_proc (old_interp->data))
-	{
-	  error (_("Could not suspend interpreter \"%s\"."),
-		 old_interp->name);
-	}
+      old_interp->suspend ();
     }
   else
     {
@@ -232,32 +193,20 @@ interp_set (struct interp *interp, int top_level)
       interpreter_p = xstrdup (interp->name);
     }
 
-  /* Run the init proc.  If it fails, try to restore the old interp.  */
-
+  /* Run the init proc.  */
   if (!interp->inited)
     {
-      if (interp->procs->init_proc != NULL)
-	{
-	  interp->data = interp->procs->init_proc (interp, top_level);
-	}
-      interp->inited = 1;
+      interp->init (top_level);
+      interp->inited = true;
     }
 
   /* Do this only after the interpreter is initialized.  */
-  current_uiout = interp->procs->ui_out_proc (interp);
+  current_uiout = interp->interp_ui_out ();
 
   /* Clear out any installed interpreter hooks/event handlers.  */
   clear_interpreter_hooks ();
 
-  if (interp->procs->resume_proc != NULL
-      && (!interp->procs->resume_proc (interp->data)))
-    {
-      if (old_interp == NULL || !interp_set (old_interp, 0))
-	internal_error (__FILE__, __LINE__,
-			_("Failed to initialize new interp \"%s\" %s"),
-			interp->name, "and could not restore old interp!\n");
-      return 0;
-    }
+  interp->resume ();
 
   if (!first_time && !interp_quiet_p (interp))
     {
@@ -265,8 +214,6 @@ interp_set (struct interp *interp, int top_level)
 		 "Switching to interpreter \"%.24s\".\n", interp->name);
       current_uiout->text (buffer);
     }
-
-  return 1;
 }
 
 /* Look up the interpreter for NAME.  If no such interpreter exists,
@@ -330,8 +277,7 @@ set_top_level_interpreter (const char *name)
   if (interp == NULL)
     error (_("Interpreter `%s' unrecognized"), name);
   /* Install it.  */
-  if (!interp_set (interp, 1))
-    error (_("Interpreter `%s' failed to initialize."), name);
+  interp_set (interp, true);
 }
 
 /* Returns the current interpreter.  */
@@ -343,7 +289,7 @@ interp_ui_out (struct interp *interp)
 
   if (interp == NULL)
     interp = ui_interp->current_interpreter;
-  return interp->procs->ui_out_proc (interp);
+  return interp->interp_ui_out ();
 }
 
 void
@@ -353,8 +299,7 @@ current_interp_set_logging (ui_file_up logfile,
   struct ui_interp_info *ui_interp = get_current_interp_info ();
   struct interp *interp = ui_interp->current_interpreter;
 
-  return interp->procs->set_logging_proc (interp, std::move (logfile),
-					  logging_redirect);
+  return interp->set_logging (std::move (logfile), logging_redirect);
 }
 
 /* Temporarily overrides the current interpreter.  */
@@ -370,14 +315,6 @@ interp_set_temp (const char *name)
   return old_interp;
 }
 
-/* Returns the interpreter's cookie.  */
-
-void *
-interp_data (struct interp *interp)
-{
-  return interp->data;
-}
-
 /* Returns the interpreter's name.  */
 
 const char *
@@ -427,8 +364,7 @@ interp_pre_command_loop (struct interp *interp)
 {
   gdb_assert (interp != NULL);
 
-  if (interp->procs->pre_command_loop_proc != NULL)
-    interp->procs->pre_command_loop_proc (interp);
+  interp->pre_command_loop ();
 }
 
 /* See interp.h  */
@@ -436,9 +372,7 @@ interp_pre_command_loop (struct interp *interp)
 int
 interp_supports_command_editing (struct interp *interp)
 {
-  if (interp->procs->supports_command_editing_proc != NULL)
-    return interp->procs->supports_command_editing_proc (interp);
-  return 0;
+  return interp->supports_command_editing ();
 }
 
 int
@@ -472,13 +406,11 @@ interp_exec (struct interp *interp, const char *command_str)
   struct gdb_exception ex;
   struct interp *save_command_interp;
 
-  gdb_assert (interp->procs->exec_proc != NULL);
-
   /* See `command_interp' for why we do this.  */
   save_command_interp = ui_interp->command_interpreter;
   ui_interp->command_interpreter = interp;
 
-  ex = interp->procs->exec_proc (interp->data, command_str);
+  ex = interp->exec (command_str);
 
   ui_interp->command_interpreter = save_command_interp;
 
@@ -539,8 +471,7 @@ interpreter_exec_cmd (char *args, int from_tty)
   old_quiet = interp_set_quiet (old_interp, 1);
   use_quiet = interp_set_quiet (interp_to_use, 1);
 
-  if (!interp_set (interp_to_use, 0))
-    error (_("Could not switch to interpreter \"%s\"."), prules[0]);
+  interp_set (interp_to_use, false);
 
   for (i = 1; i < nrules; i++)
     {
@@ -612,16 +543,6 @@ top_level_interpreter (void)
   return ui_interp->top_level_interpreter;
 }
 
-void *
-top_level_interpreter_data (void)
-{
-  struct interp *interp;
-
-  interp = top_level_interpreter ();
-  gdb_assert (interp != NULL);
-  return interp->data;
-}
-
 /* See interps.h.  */
 
 struct interp *