Make gdb::option::complete_options save processed arguments too

Currently, gdb::option::complete_options just discards any processed
option argument, because no completer needs that data.

When completing "pipe -d XXX gdbcmd XXX" however, the completer needs
to know about -d's argument (XXX), in order to know where input is
already past the gdb command and the delimiter.

In this commit, the fix for that is the factoring out of the
save_option_value_in_ctx function and calling it in complete_options.

For testing, this makes "maint show test-options-completion-result"
show the processed options too, like what the "maint test-options"
subcommands output when run.  Then, of course, gdb.base/options.exp is
adjusted.

Doing this exposed a couple latent bugs, which is what the other gdb
changes in the patch are for:

 - in the var_enum case, without the change, we'd end up with a null
   enum argument, and print:

     "-enum (null)"

 - The get_ulongest change is necessary to avoid advancing PP in a
   case where we end up throwing an error, e.g., when parsing "11x".
   Without the change the operand pointer shown by "maint show
   test-options-completion-result" would be left pointing at "x"
   instead of "11x".

gdb/ChangeLog:
2019-07-03  Pedro Alves  <palves@redhat.com>

	* cli/cli-option.c (parse_option) <var_enum>: Don't return an
	option_value with a null enumeration.
	(complete_options): Save the option values in the context.
	(save_option_value_in_ctx): New, factored out from ...
	(process_options): ... here.
	* cli/cli-utils.c (get_ulongest): Don't advance PP until the end
	of the function.
	* maint-test-options.c (test_options_opts::dump): New, factored
	out from ...
	(maintenance_test_options_command_mode): ... here.
	(maintenance_test_options_command_completion_result): Delete.
	(maintenance_test_options_command_completion_text): Update
	comment.
	(maintenance_show_test_options_completion_result): Change
	prototype.  Just print
	maintenance_test_options_command_completion_text.
	(save_completion_result): New.
	(maintenance_test_options_completer_mode): Pass options context to
	complete_options, and then save a dump.
	(_initialize_maint_test_options): Use add_cmd to install "maint
	show test-options-completion-result".

gdb/testsuite/ChangeLog:
2019-07-03  Pedro Alves  <palves@redhat.com>

	* gdb.base/options.exp (test-misc, test-flag, test-boolean)
	(test-uinteger, test-enum): Adjust res_test_gdb_... calls to pass
	the expected output in the success.

1 files changed, 67 insertions, 46 deletions

diff --git a/gdb/maint-test-options.c b/gdb/maint-test-options.c
index 599155cbfe6..7e7ef6e7992 100644
--- a/gdb/maint-test-options.c
+++ b/gdb/maint-test-options.c
@@ -133,6 +133,27 @@ struct test_options_opts
   const char *enum_opt = test_options_enum_values_xxx;
   unsigned int uint_opt = 0;
   int zuint_unl_opt = 0;
+
+  /* Dump the options to FILE.  ARGS is the remainder unprocessed
+     arguments.  */
+  void dump (ui_file *file, const char *args) const
+  {
+    fprintf_unfiltered (file,
+			_("-flag %d -xx1 %d -xx2 %d -bool %d "
+			  "-enum %s -uint %s -zuint-unl %s -- %s\n"),
+			flag_opt,
+			xx1_opt,
+			xx2_opt,
+			boolean_opt,
+			enum_opt,
+			(uint_opt == UINT_MAX
+			 ? "unlimited"
+			 : pulongest (uint_opt)),
+			(zuint_unl_opt == -1
+			 ? "unlimited"
+			 : plongest (zuint_unl_opt)),
+			args);
+  }
 };
 
 /* Option definitions for the "maintenance test-options" commands.  */
@@ -226,46 +247,48 @@ maintenance_test_options_command_mode (const char *args,
   else
     args = skip_spaces (args);
 
-  printf_unfiltered (_("-flag %d -xx1 %d -xx2 %d -bool %d "
-		       "-enum %s -uint %s -zuint-unl %s -- %s\n"),
-		     opts.flag_opt,
-		     opts.xx1_opt,
-		     opts.xx2_opt,
-		     opts.boolean_opt,
-		     opts.enum_opt,
-		     (opts.uint_opt == UINT_MAX
-		      ? "unlimited"
-		      : pulongest (opts.uint_opt)),
-		     (opts.zuint_unl_opt == -1
-		      ? "unlimited"
-		      : plongest (opts.zuint_unl_opt)),
-		     args);
+  opts.dump (gdb_stdout, args);
 }
 
-/* Variables used by the "maintenance show
-   test-options-completion-result" command.  These variables are
-   stored by the completer of the "maint test-options"
-   subcommands.  */
+/* Variable used by the "maintenance show
+   test-options-completion-result" command.  This variable is stored
+   by the completer of the "maint test-options" subcommands.
 
-/* The result of gdb::option::complete_options.  */
-static int maintenance_test_options_command_completion_result;
-/* The text at the word point after gdb::option::complete_options
-   returns.  */
+   If the completer returned false, this includes the text at the word
+   point after gdb::option::complete_options returns.  If true, then
+   this includes a dump of the processed options.  */
 static std::string maintenance_test_options_command_completion_text;
 
 /* The "maintenance show test-options-completion-result" command.  */
 
 static void
-maintenance_show_test_options_completion_result
-  (struct ui_file *file, int from_tty,
-   struct cmd_list_element *c, const char *value)
+maintenance_show_test_options_completion_result (const char *args,
+						 int from_tty)
 {
-  if (maintenance_test_options_command_completion_result)
-    fprintf_filtered (file, "1\n");
+  puts_filtered (maintenance_test_options_command_completion_text.c_str ());
+}
+
+/* Save the completion result in the global variables read by the
+   "maintenance test-options require-delimiter" command.  */
+
+static void
+save_completion_result (const test_options_opts &opts, bool res,
+			const char *text)
+{
+  if (res)
+    {
+      string_file stream;
+
+      stream.puts ("1 ");
+      opts.dump (&stream, text);
+      maintenance_test_options_command_completion_text
+	= std::move (stream.string ());
+    }
   else
-    fprintf_filtered
-      (file, _("0 %s\n"),
-       maintenance_test_options_command_completion_text.c_str ());
+    {
+      maintenance_test_options_command_completion_text
+	= string_printf ("0 %s\n", text);
+    }
 }
 
 /* Implementation of completer for the "maintenance test-options
@@ -278,17 +301,19 @@ maintenance_test_options_completer_mode (completion_tracker &tracker,
 					 const char *text,
 					 gdb::option::process_options_mode mode)
 {
+  test_options_opts opts;
+
   try
     {
-      maintenance_test_options_command_completion_result
-	= gdb::option::complete_options
-	   (tracker, &text, mode,
-	    make_test_options_options_def_group (nullptr));
-      maintenance_test_options_command_completion_text = text;
+      bool res = (gdb::option::complete_options
+		  (tracker, &text, mode,
+		   make_test_options_options_def_group (&opts)));
+
+      save_completion_result (opts, res, text);
     }
   catch (const gdb_exception_error &ex)
     {
-      maintenance_test_options_command_completion_result = 1;
+      save_completion_result (opts, true, text);
       throw;
     }
 }
@@ -445,17 +470,13 @@ Options:\n\
   set_cmd_completer_handle_brkchars
     (cmd, maintenance_test_options_unknown_is_operand_command_completer);
 
-  add_setshow_zinteger_cmd ("test-options-completion-result", class_maintenance,
-			    &maintenance_test_options_command_completion_result,
-			    _("\
-Set maintenance test-options completion result."), _("\
-Show maintenance test-options completion result."), _("\
-Show the results of completing\n\
+  add_cmd ("test-options-completion-result", class_maintenance,
+	   maintenance_show_test_options_completion_result,
+	   _("\
+Show maintenance test-options completion result.\n\
+Shows the results of completing\n\
 \"maint test-options require-delimiter\",\n\
 \"maint test-options unknown-is-error\", or\n\
 \"maint test-options unknown-is-operand\"."),
-			    NULL,
-			    maintenance_show_test_options_completion_result,
-			    &maintenance_set_cmdlist,
-			    &maintenance_show_cmdlist);
+	   &maintenance_show_cmdlist);
 }