[gdb/cli] Add a progress meter

Add a progress meter.  It's not used anywhere yet.

gdb/ChangeLog:

2020-12-16  Tom Tromey  <tom@tromey.com>
	    Tom Tromey  <tromey@redhat.com>
	    Tom de Vries  <tdevries@suse.de>

	* utils.h (get_chars_per_line): Declare.
	* utils.c (get_chars_per_line): New function.
	(fputs_maybe_filtered): Handle '\r'.
	* ui-out.h (ui_out::progress_meter): New class.
	(ui_out::progress, ui_out::do_progress_start)
	(ui_out::do_progress_notify, ui_out::do_progress_end): New
	methods.
	* ui-out.c (do_progress_end)
	(make_cleanup_ui_out_progress_begin_end, ui_out_progress): New
	functions.
	* mi/mi-out.h (mi_ui_out::do_progress_start)
	(mi_ui_out::do_progress_notify, mi_ui_out::do_progress_end): New
	methods.
	* cli-out.h (struct cli_ui_out) <do_progress_start,
	do_progress_notify, do_progress_end>: New methods.
	<enum meter_stat, struct cli_progress_info>: New.
	<m_meters>: New member.
	* cli-out.c (cli_ui_out::do_progress_start)
	(cli_ui_out::do_progress_notify, cli_ui_out::do_progress_end): New
	methods.

1 files changed, 31 insertions, 0 deletions

diff --git a/gdb/cli-out.h b/gdb/cli-out.h
index 84e957c..5f55554 100644
--- a/gdb/cli-out.h
+++ b/gdb/cli-out.h
@@ -71,6 +71,10 @@ protected:
   virtual void do_flush () override;
   virtual void do_redirect (struct ui_file *outstream) override;
 
+  virtual void do_progress_start (const std::string &, bool) override;
+  virtual void do_progress_notify (double) override;
+  virtual void do_progress_end () override;
+
   bool suppress_output ()
   { return m_suppress_output; }
 
@@ -80,6 +84,33 @@ private:
 
   std::vector<ui_file *> m_streams;
   bool m_suppress_output;
+
+  /* Represents the printing state of a progress meter.  */
+  enum meter_state
+  {
+    /* Printing will start with the next output.  */
+    START,
+    /* Printing has already started.  */
+    WORKING,
+    /* Progress printing has already started.  */
+    PROGRESS,
+    /* Printing should not be done.  */
+    NO_PRINT
+  };
+
+  /* The state of a recent progress meter.  */
+  struct cli_progress_info
+  {
+    /* The current state.  */
+    enum meter_state printing;
+    /* The name to print.  */
+    std::string name;
+    /* The last notification value.  */
+    double last_value;
+  };
+
+  /* Stack of progress meters.  */
+  std::vector<cli_progress_info> m_meters;
 };
 
 extern cli_ui_out *cli_out_new (struct ui_file *stream);