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.

gdb/ChangeLog

@@ -1,3 +1,27 @@
+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".
+
 2019-07-03  Pedro Alves  <palves@redhat.com>
 
 	* NEWS (New commands): Mention "with" and "maint with".

gdb/cli/cli-option.c

@@ -58,6 +58,8 @@ struct option_def_and_value
   gdb::optional<option_value> value;
 };
 
+static void save_option_value_in_ctx (gdb::optional<option_def_and_value> &ov);
+
 /* Info passed around when handling completion.  */
 struct parse_option_completion_info
 {
@@ -349,11 +351,12 @@ parse_option (gdb::array_view<const option_def_group> options_group,
 	      {
 		complete_on_enum (completion->tracker,
 				  match->enums, *args, *args);
-		*args = after_arg;
+		if (completion->tracker.have_completions ())
+		  return {};
 
-		option_value val;
+		/* If we don't have completions, let the
-		val.enumeration = nullptr;
+		   non-completion path throw on invalid enum value
-		return option_def_and_value {*match, match_ctx, val};
+		   below, so that completion processing stops.  */
 	      }
 	  }
 
@@ -456,6 +459,11 @@ complete_options (completion_tracker &tracker,
 		    (*args - text);
 		  return true;
 		}
+
+	      /* If the caller passed in a context, then it is
+		 interested in the option argument values.  */
+	      if (ov && ov->ctx != nullptr)
+		save_option_value_in_ctx (ov);
 	    }
 	  else
 	    {
@@ -499,6 +507,36 @@ complete_options (completion_tracker &tracker,
   return false;
 }
 
+/* Save the parsed value in the option's context.  */
+
+static void
+save_option_value_in_ctx (gdb::optional<option_def_and_value> &ov)
+{
+  switch (ov->option.type)
+    {
+    case var_boolean:
+      {
+	bool value = ov->value.has_value () ? ov->value->boolean : true;
+	*ov->option.var_address.boolean (ov->option, ov->ctx) = value;
+      }
+      break;
+    case var_uinteger:
+      *ov->option.var_address.uinteger (ov->option, ov->ctx)
+	= ov->value->uinteger;
+      break;
+    case var_zuinteger_unlimited:
+      *ov->option.var_address.integer (ov->option, ov->ctx)
+	= ov->value->integer;
+      break;
+    case var_enum:
+      *ov->option.var_address.enumeration (ov->option, ov->ctx)
+	= ov->value->enumeration;
+      break;
+    default:
+      gdb_assert_not_reached ("unhandled option type");
+    }
+}
+
 /* See cli-option.h.  */
 
 bool
@@ -534,29 +572,7 @@ process_options (const char **args,
 
       processed_any = true;
 
-      switch (ov->option.type)
+      save_option_value_in_ctx (ov);
-	{
-	case var_boolean:
-	  {
-	    bool value = ov->value.has_value () ? ov->value->boolean : true;
-	    *ov->option.var_address.boolean (ov->option, ov->ctx) = value;
-	  }
-	  break;
-	case var_uinteger:
-	  *ov->option.var_address.uinteger (ov->option, ov->ctx)
-	    = ov->value->uinteger;
-	  break;
-	case var_zuinteger_unlimited:
-	  *ov->option.var_address.integer (ov->option, ov->ctx)
-	    = ov->value->integer;
-	  break;
-	case var_enum:
-	  *ov->option.var_address.enumeration (ov->option, ov->ctx)
-	    = ov->value->enumeration;
-	  break;
-	default:
-	  gdb_assert_not_reached ("unhandled option type");
-	}
     }
 }
 

gdb/cli/cli-utils.c

@@ -60,13 +60,14 @@ get_ulongest (const char **pp, int trailer)
     }
   else
     {
-      retval = strtoulst (p, pp, 0);
+      const char *end = p;
-      if (p == *pp)
+      retval = strtoulst (p, &end, 0);
+      if (p == end)
 	{
 	  /* There is no number here.  (e.g. "cond a == b").  */
 	  error (_("Expected integer at: %s"), p);
 	}
-      p = *pp;
+      p = end;
     }
 
   if (!(isspace (*p) || *p == '\0' || *p == trailer))

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 "
+  opts.dump (gdb_stdout, args);
-		       "-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);
 }
 
-/* Variables used by the "maintenance show
+/* Variable used by the "maintenance show
-   test-options-completion-result" command.  These variables are
+   test-options-completion-result" command.  This variable is stored
-   stored by the completer of the "maint test-options"
+   by the completer of the "maint test-options" subcommands.
-   subcommands.  */
 
-/* The result of gdb::option::complete_options.  */
+   If the completer returned false, this includes the text at the word
-static int maintenance_test_options_command_completion_result;
+   point after gdb::option::complete_options returns.  If true, then
-/* The text at the word point after gdb::option::complete_options
+   this includes a dump of the processed options.  */
-   returns.  */
 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
+maintenance_show_test_options_completion_result (const char *args,
-  (struct ui_file *file, int from_tty,
+						 int from_tty)
-   struct cmd_list_element *c, const char *value)
 {
-  if (maintenance_test_options_command_completion_result)
+  puts_filtered (maintenance_test_options_command_completion_text.c_str ());
-    fprintf_filtered (file, "1\n");
+}
+
+/* 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
-       maintenance_test_options_command_completion_text.c_str ());
+	= 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
+      bool res = (gdb::option::complete_options
-	= gdb::option::complete_options
 		  (tracker, &text, mode,
-	    make_test_options_options_def_group (nullptr));
+		   make_test_options_options_def_group (&opts)));
-      maintenance_test_options_command_completion_text = text;
+
+      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,
+  add_cmd ("test-options-completion-result", class_maintenance,
-			    &maintenance_test_options_command_completion_result,
+	   maintenance_show_test_options_completion_result,
 	   _("\
-Set maintenance test-options completion result."), _("\
+Show maintenance test-options completion result.\n\
-Show maintenance test-options completion result."), _("\
+Shows the results of completing\n\
-Show 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);
 }

gdb/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+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.
+
 2019-07-03  Pedro Alves  <palves@redhat.com>
 
 	* lib/completion-support.exp (test_gdb_complete_tab_multiple):

gdb/testsuite/gdb.base/options.exp

@@ -486,21 +486,27 @@ proc_with_prefix test-misc {variant} {
     }
 
     # Completing at "-" should list all options.
-    res_test_gdb_complete_multiple "1" "$cmd " "-" "" $all_options
+    res_test_gdb_complete_multiple \
+	"1 [expect_none "-"]" \
+	"$cmd " "-" "" $all_options
 
     # Now with a double dash.
     gdb_test "$cmd --" [expect_none ""]
 
     # "--" is recognized by options completer, gdb auto-appends a
     # space.
-    test_completer_recognizes 1 "$cmd --"
+    test_completer_recognizes \
+	"1 [expect_none "--"]" \
+	"$cmd --"
 
     # Now with a double dash, plus a dash as operand.
     gdb_test "$cmd -- -" [expect_none "-"]
     res_test_gdb_complete_none "0 -" "$cmd -- -"
 
     # Completing an unambiguous option just appends an empty space.
-    test_completer_recognizes 1 "$cmd -flag"
+    test_completer_recognizes \
+	"1 [expect_none "-flag"]" \
+	"$cmd -flag"
 
     # Try running an ambiguous option.
     if {$variant == "require-delimiter"} {
@@ -540,10 +546,14 @@ proc_with_prefix test-flag {variant} {
     set cmd [make_cmd $variant]
 
     # Completing a flag just appends a space.
-    test_completer_recognizes 1 "$cmd -flag"
+    test_completer_recognizes \
+	"1 [expect_none "-flag"]" \
+	"$cmd -flag"
 
     # Add a dash, and all options should be shown.
-    test_gdb_complete_multiple "$cmd  -flag " "-" "" $all_options
+    res_test_gdb_complete_multiple \
+	"1 [expect_flag "-"]" \
+	"$cmd  -flag " "-" "" $all_options
 
     # Basic smoke tests of accepted / not accepted values.
 
@@ -582,7 +592,9 @@ proc_with_prefix test-flag {variant} {
     # "on/off".
 
     if {$variant == "require-delimiter"} {
-	res_test_gdb_complete_none "1" "$cmd -flag o"
+	res_test_gdb_complete_none \
+	    "1 [expect_flag "o"]" \
+	    "$cmd -flag o"
 
 	gdb_test "$cmd -flag o" [expect_none "-flag o"]
     } else {
@@ -612,7 +624,9 @@ proc_with_prefix test-boolean {variant} {
     #   E.g., "frame apply all -past-main COMMAND".
 
     if {$variant == "require-delimiter"} {
-	res_test_gdb_complete_multiple 1 "$cmd -bool " "" "" {
+	res_test_gdb_complete_multiple \
+	    "1 [expect_none ""]" \
+	    "$cmd -bool " "" "" {
 	    "-bool"
 	    "-enum"
 	    "-flag"
@@ -628,7 +642,9 @@ proc_with_prefix test-boolean {variant} {
     }
 
     # Add another dash, and "on/off" are no longer offered:
-    res_test_gdb_complete_multiple 1 "$cmd -bool " "-" ""  $all_options
+    res_test_gdb_complete_multiple \
+	"1 [expect_bool "-"]" \
+	"$cmd -bool " "-" ""  $all_options
 
     # Basic smoke tests of accepted / not accepted values.
 
@@ -643,20 +659,25 @@ proc_with_prefix test-boolean {variant} {
     # However, the completer does recognize them if you start typing
     # the boolean value.
     foreach value {"0" "1"} {
-	test_completer_recognizes 1 "$cmd -bool $value"
+	test_completer_recognizes \
+	    "1 [expect_none ""]" \
+	    "$cmd -bool $value"
     }
     foreach value {"of" "off"} {
-	res_test_gdb_complete_unique 1 \
+	res_test_gdb_complete_unique \
+	    "1 [expect_none ""]" \
 	    "$cmd -bool $value" \
 	    "$cmd -bool off"
     }
     foreach value {"y" "ye" "yes"} {
-	res_test_gdb_complete_unique 1 \
+	res_test_gdb_complete_unique \
+	    "1 [expect_none ""]" \
 	    "$cmd -bool $value" \
 	    "$cmd -bool yes"
     }
     foreach value {"n" "no"} {
-	res_test_gdb_complete_unique 1 \
+	res_test_gdb_complete_unique \
+	    "1 [expect_none ""]" \
 	    "$cmd -bool $value" \
 	    "$cmd -bool no"
     }
@@ -668,7 +689,8 @@ proc_with_prefix test-boolean {variant} {
 	"enabl"
 	"enable"
     } {
-	res_test_gdb_complete_unique 1 \
+	res_test_gdb_complete_unique \
+	    "1 [expect_none ""]" \
 	    "$cmd -bool $value" \
 	    "$cmd -bool enable"
     }
@@ -681,13 +703,16 @@ proc_with_prefix test-boolean {variant} {
 	"disabl"
 	"disable"
     } {
-	res_test_gdb_complete_unique 1 \
+	res_test_gdb_complete_unique \
+	    "1 [expect_none ""]" \
 	    "$cmd -bool $value" \
 	    "$cmd -bool disable"
     }
 
     if {$variant == "require-delimiter"} {
-	res_test_gdb_complete_none "1" "$cmd -bool xxx"
+	res_test_gdb_complete_none \
+	    "1 [expect_none "xxx"]" \
+	    "$cmd -bool xxx"
     } else {
 	res_test_gdb_complete_none "0 xxx" "$cmd -bool xxx"
     }
@@ -763,7 +788,9 @@ proc_with_prefix test-boolean {variant} {
     # Completing after a boolean option + "o" does list "on/off",
     # though.
     if {$variant == "require-delimiter"} {
-	res_test_gdb_complete_multiple 1 "$cmd -bool " "o" "" {
+	res_test_gdb_complete_multiple \
+	    "1 [expect_none "o"]" \
+	    "$cmd -bool " "o" "" {
 	    "off"
 	    "on"
 	}
@@ -783,17 +810,22 @@ proc_with_prefix test-uinteger {variant option} {
     set cmd "[make_cmd $variant] -$option"
 
     # Test completing a uinteger option:
-    res_test_gdb_complete_multiple 1 "$cmd " "" "" {
+    res_test_gdb_complete_multiple \
+	"1 [expect_none ""]" \
+	"$cmd " "" "" {
 	"NUMBER"
 	"unlimited"
     }
 
     # NUMBER above is just a placeholder, make sure we don't complete
     # it as a valid option.
-    res_test_gdb_complete_none 1 "$cmd NU"
+    res_test_gdb_complete_none \
+	"1 [expect_none "NU"]" \
+	"$cmd NU"
 
     # "unlimited" is valid though.
-    res_test_gdb_complete_unique 1 \
+    res_test_gdb_complete_unique \
+	"1 [expect_none "u"]" \
 	"$cmd u" \
 	"$cmd unlimited"
 
@@ -815,24 +847,34 @@ proc_with_prefix test-uinteger {variant option} {
 
     # Don't offer completions until we're past the
     # -uinteger/-zuinteger-unlimited argument.
-    res_test_gdb_complete_none 1 "$cmd 1"
+    res_test_gdb_complete_none \
+	"1 [expect_none ""]" \
+	"$cmd 1"
 
     # A number of invalid values.
     foreach value {"x" "x " "1a" "1a " "1-" "1- " "unlimitedx"} {
-	res_test_gdb_complete_none 1 "$cmd $value"
+	res_test_gdb_complete_none \
+	    "1 [expect_none $value]" \
+	    "$cmd $value"
     }
 
     # Try "-1".
     if {$option == "uinteger"} {
 	# -1 is invalid uinteger.
 	foreach value {"-1" "-1 "} {
-	    res_test_gdb_complete_none 1 "$cmd $value"
+	    res_test_gdb_complete_none \
+		"1 [expect_none ""]" \
+		"$cmd $value"
 	}
     } else {
 	# -1 is valid for zuinteger-unlimited.
-	res_test_gdb_complete_none 1 "$cmd -1"
+	res_test_gdb_complete_none \
+	    "1 [expect_none ""]" \
+	    "$cmd -1"
 	if {$variant == "require-delimiter"} {
-	    res_test_gdb_complete_multiple 1 "$cmd -1 " "" "-" $all_options
+	    res_test_gdb_complete_multiple \
+		"1 [expect_integer $option "unlimited" ""]" \
+		"$cmd -1 " "" "-" $all_options
 	} else {
 	    res_test_gdb_complete_none "0 " "$cmd -1 "
 	}
@@ -846,7 +888,9 @@ proc_with_prefix test-uinteger {variant option} {
     #  - for !require-delimiter commands, completion offers nothing
     #    and returns false.
     if {$variant == "require-delimiter"} {
-	res_test_gdb_complete_multiple 1 "$cmd 1 " "" "-" $all_options
+	res_test_gdb_complete_multiple \
+	    "1 [expect_integer $option 1 ""]" \
+	    "$cmd 1 " "" "-" $all_options
     } else {
 	res_test_gdb_complete_none "0 " "$cmd 1 "
     }
@@ -854,7 +898,9 @@ proc_with_prefix test-uinteger {variant option} {
     # Test completing non-option arguments after "-uinteger 1 ".
     foreach operand {"x" "x " "1a" "1a " "1-" "1- "} {
 	if {$variant == "require-delimiter"} {
-	    res_test_gdb_complete_none 1 "$cmd 1 $operand"
+	    res_test_gdb_complete_none \
+		"1 [expect_integer $option 1 $operand]" \
+		"$cmd 1 $operand"
 	} else {
 	    res_test_gdb_complete_none "0 $operand" "$cmd 1 $operand"
 	}
@@ -864,7 +910,9 @@ proc_with_prefix test-uinteger {variant option} {
 	if {$variant == "unknown-is-operand"} {
 	    res_test_gdb_complete_none "0 $operand" "$cmd 1 $operand"
 	} else {
-	    res_test_gdb_complete_none 1 "$cmd 1 $operand"
+	    res_test_gdb_complete_none \
+		"1 [expect_integer $option 1 $operand]" \
+		"$cmd 1 $operand"
 	}
     }
 }
@@ -873,7 +921,9 @@ proc_with_prefix test-uinteger {variant option} {
 proc_with_prefix test-enum {variant} {
     set cmd [make_cmd $variant]
 
-    res_test_gdb_complete_multiple 1 "$cmd -enum " "" "" {
+    res_test_gdb_complete_multiple \
+	"1 [expect_none ""]" \
+	"$cmd -enum " "" "" {
 	"xxx"
 	"yyy"
 	"zzz"
@@ -882,7 +932,9 @@ proc_with_prefix test-enum {variant} {
     # Check that "-" where a value is expected does not show the
     # command's options.  I.e., an enum's value is not optional.
     # Check both completion and running the command.
-    res_test_gdb_complete_none 1 "$cmd -enum -"
+    res_test_gdb_complete_none \
+	"1 [expect_none "-"]" \
+	"$cmd -enum -"
     gdb_test "$cmd -enum --"\
 	"Requires an argument. Valid arguments are xxx, yyy, zzz\\."