[PATCH] [PR cli/16269] Add completer for the inferior commands

[Lancelot SIX via Gdb-patches <gdb-patches@sourceware.org>]

This patch adds or improves completers for the following commands:

* inferior
* add-inferior
* clone-inferior
* remove-inferiors
* kill inferiors
* detach inferiors

Before the patch, the 'inferior', 'clone-inferior', 'remove-inferiors',
'kill inferiors' and 'detach inferiors' commands complete on symbols
which is unexpected. The 'add-inferior' only completes on filename and
fails to complete on option flags.

Tested with 'make check TESTS="gdb.base/completion.exp"'

My copyright assignment is still pending.

gdb/ChangeLog:

2020-12-22  Lancelot SIX  <lsix@lancelotsix.com>

	PR cli/16269
	* inferior.c (inferior_id_completer): add completer
	(add_inferior_completer): add completer
	(clone_inferior_completer): add completer
	(initialize_inferiors): declare use of completers

gdb/testsuite/ChangeLog:

2020-12-22  Lancelot SIX  <lsix@lancelotsix.com>

	PR cli/16269
	* gdb.base/completion.exp: test completion of inferior related
	commands
---
 gdb/inferior.c                        | 61 ++++++++++++++++++++++++---
 gdb/testsuite/gdb.base/completion.exp | 18 ++++++++
 2 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/gdb/inferior.c b/gdb/inferior.c
index a6652b6920..406e5030d7 100644
--- a/gdb/inferior.c
+++ b/gdb/inferior.c
@@ -539,6 +539,22 @@ print_inferior (struct ui_out *uiout, const char *requested_inferiors)
     }
 }
 
+/* Complete available inferior IDs */
+
+static void
+inferior_id_completer (struct cmd_list_element *ignore,
+		       completion_tracker &tracker,
+		       const char *text, const char *word)
+{
+  for (inferior *inf : all_inferiors ())
+    {
+      std::string const st = std::to_string (inf->num);
+      if (st.rfind(text, 0) == 0)
+	tracker.add_completion
+	  (make_completion_match_str (st.c_str (), text, word));
+    }
+}
+
 static void
 detach_inferior_command (const char *args, int from_tty)
 {
@@ -833,6 +849,20 @@ add_inferior_command (const char *args, int from_tty)
     }
 }
 
+/* Completer for the add-inferior command */
+
+static void
+add_inferior_completer (struct cmd_list_element *cmd,
+			completion_tracker &tracker,
+			const char *text, const char *word)
+{
+  static const char * const options[] = {
+    "-copies", "-exec", "-no-connection", nullptr
+  };
+  complete_on_enum (tracker, options, text, word);
+  filename_completer (cmd, tracker, text, word);
+}
+
 /* clone-inferior [-copies N] [ID] [-no-connection] */
 
 static void
@@ -919,6 +949,20 @@ clone_inferior_command (const char *args, int from_tty)
     }
 }
 
+/* Completer for the clone-inferior command */
+
+static void
+clone_inferior_completer (struct cmd_list_element *cmd,
+			  completion_tracker &tracker,
+			  const char *text, const char *word)
+{
+  static const char * const options[] = {
+    "-copies", "-no-connection", nullptr
+  };
+  complete_on_enum (tracker, options, text, word);
+  inferior_id_completer (cmd, tracker, text, word);
+}
+
 /* Print notices when new inferiors are created and die.  */
 static void
 show_print_inferior_events (struct ui_file *file, int from_tty,
@@ -981,13 +1025,14 @@ as main program.\n\
 By default, the new inferior inherits the current inferior's connection.\n\
 If -no-connection is specified, the new inferior begins with\n\
 no target connection yet."));
-  set_cmd_completer (c, filename_completer);
+  set_cmd_completer (c, add_inferior_completer);
 
-  add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
+  c = add_com ("remove-inferiors", no_class, remove_inferior_command, _("\
 Remove inferior ID (or list of IDs).\n\
 Usage: remove-inferiors ID..."));
+  set_cmd_completer(c, inferior_id_completer);
 
-  add_com ("clone-inferior", no_class, clone_inferior_command, _("\
+  c = add_com ("clone-inferior", no_class, clone_inferior_command, _("\
 Clone inferior ID.\n\
 Usage: clone-inferior [-copies N] [-no-connection] [ID]\n\
 Add N copies of inferior ID.  The new inferiors have the same\n\
@@ -997,22 +1042,26 @@ that is cloned.\n\
 By default, the new inferiors inherit the copied inferior's connection.\n\
 If -no-connection is specified, the new inferiors begin with\n\
 no target connection yet."));
+  set_cmd_completer (c, clone_inferior_completer);
 
-  add_cmd ("inferiors", class_run, detach_inferior_command, _("\
+  c = add_cmd ("inferiors", class_run, detach_inferior_command, _("\
 Detach from inferior ID (or list of IDS).\n\
 Usage; detach inferiors ID..."),
 	   &detachlist);
+  set_cmd_completer(c, inferior_id_completer);
 
-  add_cmd ("inferiors", class_run, kill_inferior_command, _("\
+  c = add_cmd ("inferiors", class_run, kill_inferior_command, _("\
 Kill inferior ID (or list of IDs).\n\
 Usage: kill inferiors ID..."),
 	   &killlist);
+  set_cmd_completer(c, inferior_id_completer);
 
-  add_cmd ("inferior", class_run, inferior_command, _("\
+  c = add_cmd ("inferior", class_run, inferior_command, _("\
 Use this command to switch between inferiors.\n\
 Usage: inferior ID\n\
 The new inferior ID must be currently known."),
 	   &cmdlist);
+  set_cmd_completer(c, inferior_id_completer);
 
   add_setshow_boolean_cmd ("inferior-events", no_class,
 	 &print_inferior_events, _("\
diff --git a/gdb/testsuite/gdb.base/completion.exp b/gdb/testsuite/gdb.base/completion.exp
index 8000d52049..cc3b7b7182 100644
--- a/gdb/testsuite/gdb.base/completion.exp
+++ b/gdb/testsuite/gdb.base/completion.exp
@@ -975,3 +975,21 @@ test_gdb_complete_unique "xxx_yyy_" "xxx_yyy_zzz"
 gdb_test_no_output "alias set aaa_bbb_ccc=set debug"
 gdb_test_no_output "maint deprecate set aaa_bbb_ccc"
 test_gdb_complete_unique "set aaa_bbb_" "set aaa_bbb_ccc"
+
+# Test completion of inferior related commands
+
+gdb_test "complete add-inferior -cop" "-copies"
+gdb_test "complete add-inferior -no-con" "-no-connection"
+gdb_test "complete add-inferior -e" "-exec"
+
+gdb_test "complete clone-inferior -c" "-copies"
+gdb_test "complete clone-inferior -n" "-no-connection"
+
+# The following test will ensure that the completer yields the list of
+# available inferiors. We expect to only have 1 present, with ID '1'
+gdb_test "complete clone-inferior " ".*clone-inferior 1.*"
+
+gdb_test "complete remove-inferiors " "remove-inferiors 1"
+gdb_test "complete kill inferiors " "kill inferiors 1"
+gdb_test "complete detach inferiors " "detach inferiors 1"
+gdb_test "complete inferior " "inferior 1"
-- 
2.29.2