Patchwork [RFA,1/3] Implement convenience functions to examine GDB settings.

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Submitter Philippe Waroquiers
Date April 28, 2019, 3:18 p.m.
Message ID <20190428151816.31598-2-philippe.waroquiers@skynet.be>
Download mbox | patch
Permalink /patch/32440/
State New
Headers show

Comments

Philippe Waroquiers - April 28, 2019, 3:18 p.m.
The new convenience functions $_gdb_setting and $_gdb_int_setting
provide access to the GDB settings in user-defined commands.
---
 gdb/ChangeLog         |  10 ++++
 gdb/cli/cli-cmds.c    | 105 ++++++++++++++++++++++++++++++++++++++++++
 gdb/cli/cli-setshow.c |  71 +++++++++++++++-------------
 gdb/cli/cli-setshow.h |   5 ++
 4 files changed, 158 insertions(+), 33 deletions(-)

Patch

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4f595922f6..4835c6fae5 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -6023,3 +6023,13 @@  version-control: never
 coding: utf-8
 End:
 
+2019-04-28  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
+
+	* cli/cli-cmds.c (setting_cmd, gdb_int_setting_internal_fn,
+	gdb_setting_internal_fn): New functions.
+	(_initialize_cli_cmds): Define the new convenience functions.
+	* cli/cli-setshow.h (do_print_setting): New declaration.
+	* cli/cli-setshow.c (do_print_setting): New function (mostly
+	copied from do_show_command).
+	(do_show_command): Call do_print_setting.
+	(do_print_setting): New function.
diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index 5f3b973f06..b1498452ba 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -1664,6 +1664,100 @@  show_max_user_call_depth (struct ui_file *file, int from_tty,
 		    value);
 }
 
+/* Returns the cmd_list_element corresponding to the first argument
+   of ARGV, which must contain one single value.
+   Throws an error if no value provided, or value not correct.
+   FNNAME is used in the error message.  */
+
+static cmd_list_element *
+setting_cmd (const char *fnname, int argc, struct value **argv)
+{
+  if (argc == 0)
+    error (_("You must provide an argument to %s"), fnname);
+  if (argc != 1)
+    error (_("You can only provide one argument to %s"), fnname);
+
+  struct type *type0 = check_typedef (value_type (argv[0]));
+
+  if (TYPE_CODE (type0) != TYPE_CODE_ARRAY
+      && TYPE_CODE (type0) != TYPE_CODE_STRING)
+    error (_("First argument of %s must be a string."), fnname);
+
+  int len0 = TYPE_LENGTH (type0);
+  std::vector<char> arg0 (len0);
+
+  memcpy (arg0.data (), value_contents (argv[0]), len0);
+
+  const char *a0 = arg0.data ();
+  cmd_list_element *cmd = lookup_cmd (&a0, showlist, "", -1, 0);
+
+  if (cmd == nullptr || cmd_type (cmd) != show_cmd)
+    error (_("First argument of %s must be a "
+	     "valid setting of the 'show' command."), fnname);
+
+  return cmd;
+}
+
+/* Implementation of the convenience function $_gdb_int_setting.  */
+
+static struct value *
+gdb_int_setting_internal_fn (struct gdbarch *gdbarch,
+			     const struct language_defn *language,
+			     void *cookie, int argc, struct value **argv)
+{
+  cmd_list_element *cmd = setting_cmd ("$_gdb_int_setting", argc, argv);
+
+  switch (cmd->var_type)
+    {
+    case var_boolean:
+    case var_integer:
+    case var_zinteger:
+    case var_zuinteger_unlimited:
+      return value_from_longest (builtin_type (gdbarch)->builtin_int,
+				 *(int *) cmd->var);
+    case var_auto_boolean:
+      {
+	int val = *(int *) cmd->var;
+
+	if (val == 0)
+	  val = 1;
+	else if (val == 1)
+	  val = 0;
+	return value_from_longest (builtin_type (gdbarch)->builtin_int,
+				   val);
+      }
+    case var_uinteger:
+      if (*(unsigned int *) cmd->var == UINT_MAX)
+	return value_from_longest (builtin_type (gdbarch)->builtin_int,
+				   0);
+      else
+	return value_from_longest (builtin_type (gdbarch)->builtin_int,
+				   *(unsigned int *) cmd->var);
+    case var_zuinteger:
+      return value_from_longest (builtin_type (gdbarch)->builtin_int,
+				 *(unsigned int *) cmd->var);
+    default:
+      error (_("Setting type not convertible to integer"));
+    }
+}
+
+/* Implementation of the convenience function $_gdb_setting.  */
+
+static struct value *
+gdb_setting_internal_fn (struct gdbarch *gdbarch,
+			 const struct language_defn *language,
+			 void *cookie, int argc, struct value **argv)
+{
+  cmd_list_element *cmd = setting_cmd ("$_gdb_setting", argc, argv);
+  string_file stb;
+
+  do_print_setting (&stb, cmd);
+
+  return value_cstring (stb.c_str (), strlen (stb.c_str ()),
+			builtin_type (gdbarch)->builtin_char);
+}
+
+
 void
 _initialize_cli_cmds (void)
 {
@@ -1787,6 +1881,17 @@  Generic command for showing things about the debugger."),
   /* Another way to get at the same thing.  */
   add_info ("set", show_command, _("Show all GDB settings."));
 
+  add_internal_function ("_gdb_setting", _("\
+$_gdb_setting - returns the value of a GDB setting as a string.\n\
+Usage: $_gdb_setting (setting)"),
+			 gdb_setting_internal_fn, NULL);
+
+  add_internal_function ("_gdb_int_setting", _("\
+$_gdb_int_setting - returns the value of an integer GDB setting as an integer.\n\
+Usage: $_int_gdb_int_setting (setting)\n\
+Throws an error if SETTING cannot be converted to an integer."),
+			 gdb_int_setting_internal_fn, NULL);
+
   add_cmd ("commands", no_set_class, show_commands, _("\
 Show the history of commands you typed.\n\
 You can supply a command number to start with, or a `+' to start after\n\
diff --git a/gdb/cli/cli-setshow.c b/gdb/cli/cli-setshow.c
index 5b87f905d0..eac5d48ea3 100644
--- a/gdb/cli/cli-setshow.c
+++ b/gdb/cli/cli-setshow.c
@@ -551,55 +551,42 @@  do_set_command (const char *arg, int from_tty, struct cmd_list_element *c)
     }
 }
 
-/* Do a "show" command.  ARG is NULL if no argument, or the
-   text of the argument, and FROM_TTY is nonzero if this command is
-   being entered directly by the user (i.e. these are just like any
-   other command).  C is the command list element for the command.  */
+/* See cli-setshow.h.  */
 
 void
-do_show_command (const char *arg, int from_tty, struct cmd_list_element *c)
+do_print_setting (string_file *stb, struct cmd_list_element *c)
 {
-  struct ui_out *uiout = current_uiout;
-
-  gdb_assert (c->type == show_cmd);
-
-  string_file stb;
-
-  /* Possibly call the pre hook.  */
-  if (c->pre_show_hook)
-    (c->pre_show_hook) (c);
-
   switch (c->var_type)
     {
     case var_string:
       if (*(char **) c->var)
-	stb.putstr (*(char **) c->var, '"');
+	stb->putstr (*(char **) c->var, '"');
       break;
     case var_string_noescape:
     case var_optional_filename:
     case var_filename:
     case var_enum:
       if (*(char **) c->var)
-	stb.puts (*(char **) c->var);
+	stb->puts (*(char **) c->var);
       break;
     case var_boolean:
-      stb.puts (*(int *) c->var ? "on" : "off");
+      stb->puts (*(int *) c->var ? "on" : "off");
       break;
     case var_auto_boolean:
       switch (*(enum auto_boolean*) c->var)
 	{
 	case AUTO_BOOLEAN_TRUE:
-	  stb.puts ("on");
+	  stb->puts ("on");
 	  break;
 	case AUTO_BOOLEAN_FALSE:
-	  stb.puts ("off");
+	  stb->puts ("off");
 	  break;
 	case AUTO_BOOLEAN_AUTO:
-	  stb.puts ("auto");
+	  stb->puts ("auto");
 	  break;
 	default:
 	  internal_error (__FILE__, __LINE__,
-			  _("do_show_command: "
+			  _("do_print_setting: "
 			    "invalid var_auto_boolean"));
 	  break;
 	}
@@ -608,35 +595,53 @@  do_show_command (const char *arg, int from_tty, struct cmd_list_element *c)
     case var_zuinteger:
       if (c->var_type == var_uinteger
 	  && *(unsigned int *) c->var == UINT_MAX)
-	stb.puts ("unlimited");
+	stb->puts ("unlimited");
       else
-	stb.printf ("%u", *(unsigned int *) c->var);
+	stb->printf ("%u", *(unsigned int *) c->var);
       break;
     case var_integer:
     case var_zinteger:
       if (c->var_type == var_integer
 	  && *(int *) c->var == INT_MAX)
-	stb.puts ("unlimited");
+	stb->puts ("unlimited");
       else
-	stb.printf ("%d", *(int *) c->var);
+	stb->printf ("%d", *(int *) c->var);
       break;
     case var_zuinteger_unlimited:
       {
 	if (*(int *) c->var == -1)
-	  stb.puts ("unlimited");
+	  stb->puts ("unlimited");
 	else
-	  stb.printf ("%d", *(int *) c->var);
+	  stb->printf ("%d", *(int *) c->var);
       }
       break;
     default:
-      error (_("gdb internal error: bad var_type in do_show_command"));
+      error (_("gdb internal error: bad var_type in do_print_setting"));
     }
+}
+
+/* Do a "show" command.  ARG is NULL if no argument, or the
+   text of the argument, and FROM_TTY is nonzero if this command is
+   being entered directly by the user (i.e. these are just like any
+   other command).  C is the command list element for the command.  */
+
+void
+do_show_command (const char *arg, int from_tty, struct cmd_list_element *c)
+{
+  struct ui_out *uiout = current_uiout;
+
+  gdb_assert (c->type == show_cmd);
+
+  string_file stb;
+
+  /* Possibly call the pre hook.  */
+  if (c->pre_show_hook)
+    (c->pre_show_hook) (c);
 
+  do_print_setting (&stb, c);
 
-  /* FIXME: cagney/2005-02-10: Need to split this in half: code to
-     convert the value into a string (esentially the above); and
-     code to print the value out.  For the latter there should be
-     MI and CLI specific versions.  */
+  /* FIXME: cagney/2005-02-10: For code to print the value out,
+     there should be MI and CLI specific versions.  */
 
   if (uiout->is_mi_like_p ())
     uiout->field_stream ("value", stb);
diff --git a/gdb/cli/cli-setshow.h b/gdb/cli/cli-setshow.h
index e4d13c3510..27ef5ea387 100644
--- a/gdb/cli/cli-setshow.h
+++ b/gdb/cli/cli-setshow.h
@@ -31,4 +31,9 @@  extern void do_show_command (const char *arg, int from_tty,
 extern void cmd_show_list (struct cmd_list_element *list, int from_tty,
 			   const char *prefix);
 
+/* Prints in STB the current value of the GDB setting shown by C.  */
+
+void
+do_print_setting (string_file *stb, struct cmd_list_element *c);
+
 #endif /* CLI_CLI_SETSHOW_H */