gdb/skip.c - third_party/binutils-gdb - Git at Google

 /* Skipping uninteresting files and functions while stepping.

    Copyright (C) 2011-2013 Free Software Foundation, Inc.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 #include "defs.h"
 #include "skip.h"
 #include "value.h"
 #include "valprint.h"
 #include "ui-out.h"
 #include "gdb_string.h"
 #include "symtab.h"
 #include "gdbcmd.h"
 #include "command.h"
 #include "completer.h"
 #include "stack.h"
 #include "cli/cli-utils.h"
 #include "arch-utils.h"
 #include "linespec.h"
 #include "objfiles.h"
 #include "exceptions.h"
 #include "breakpoint.h" /* for get_sal_arch () */
 #include "source.h"
 #include "filenames.h"

 struct skiplist_entry
 {
   int number;

   /* NULL if this isn't a skiplist entry for an entire file.
      The skiplist entry owns this pointer.  */
   char *filename;

   /* The name of the marked-for-skip function, if this is a skiplist
      entry for a function.
      The skiplist entry owns this pointer.  */
   char *function_name;

   int enabled;

   struct skiplist_entry *next;
 };

 static void add_skiplist_entry (struct skiplist_entry *e);
 static void skip_function (const char *name);

 static struct skiplist_entry *skiplist_entry_chain;
 static int skiplist_entry_count;

 #define ALL_SKIPLIST_ENTRIES(E) \
   for (E = skiplist_entry_chain; E; E = E->next)

 #define ALL_SKIPLIST_ENTRIES_SAFE(E,TMP) \
   for (E = skiplist_entry_chain;         \
        E ? (TMP = E->next, 1) : 0;       \
        E = TMP)

 static void
 skip_file_command (char *arg, int from_tty)
 {
   struct skiplist_entry *e;
   struct symtab *symtab;
   const char *filename = NULL;

   /* If no argument was given, try to default to the last
      displayed codepoint.  */
   if (arg == NULL)
     {
       symtab = get_last_displayed_symtab ();
       if (symtab == NULL)
 	error (_("No default file now."));

       /* It is not a typo, symtab_to_filename_for_display woule be needlessly
 	 ambiguous.  */
       filename = symtab_to_fullname (symtab);
     }
   else
     {
       symtab = lookup_symtab (arg);
       if (symtab == NULL)
 	{
 	  fprintf_filtered (gdb_stderr, _("No source file named %s.\n"), arg);
 	  if (!nquery (_("\
 Ignore file pending future shared library load? ")))
 	    return;
 	}
       /* Do not use SYMTAB's filename, later loaded shared libraries may match
          given ARG but not SYMTAB's filename.  */
       filename = arg;
     }

   e = XZALLOC (struct skiplist_entry);
   e->filename = xstrdup (filename);
   e->enabled = 1;

   add_skiplist_entry (e);

   printf_filtered (_("File %s will be skipped when stepping.\n"), filename);
 }

 static void
 skip_function_command (char *arg, int from_tty)
 {
   const char *name = NULL;

   /* Default to the current function if no argument is given.  */
   if (arg == NULL)
     {
       CORE_ADDR pc;

       if (!last_displayed_sal_is_valid ())
 	error (_("No default function now."));

       pc = get_last_displayed_addr ();
       if (!find_pc_partial_function (pc, &name, NULL, NULL))
 	{
 	  error (_("No function found containing current program point %s."),
 		  paddress (get_current_arch (), pc));
 	}
       skip_function (name);
     }
   else
     {
       if (lookup_symbol (arg, NULL, VAR_DOMAIN, NULL) == NULL)
         {
 	  fprintf_filtered (gdb_stderr,
 			    _("No function found named %s.\n"), arg);

 	  if (nquery (_("\
 Ignore function pending future shared library load? ")))
 	    {
 	      /* Add the unverified skiplist entry.  */
 	      skip_function (arg);
 	    }
 	  return;
 	}

       skip_function (arg);
     }
 }

 static void
 skip_info (char *arg, int from_tty)
 {
   struct skiplist_entry *e;
   int num_printable_entries = 0;
   struct value_print_options opts;
   struct cleanup *tbl_chain;

   get_user_print_options (&opts);

   /* Count the number of rows in the table and see if we need space for a
      64-bit address anywhere.  */
   ALL_SKIPLIST_ENTRIES (e)
     if (arg == NULL || number_is_in_list (arg, e->number))
       num_printable_entries++;

   if (num_printable_entries == 0)
     {
       if (arg == NULL)
 	ui_out_message (current_uiout, 0, _("\
 Not skipping any files or functions.\n"));
       else
 	ui_out_message (current_uiout, 0,
 			_("No skiplist entries found with number %s.\n"), arg);

       return;
     }

   tbl_chain = make_cleanup_ui_out_table_begin_end (current_uiout, 4,
 						   num_printable_entries,
 						   "SkiplistTable");

   ui_out_table_header (current_uiout, 7, ui_left, "number", "Num");      /* 1 */
   ui_out_table_header (current_uiout, 14, ui_left, "type", "Type");      /* 2 */
   ui_out_table_header (current_uiout, 3, ui_left, "enabled", "Enb");     /* 3 */
   ui_out_table_header (current_uiout, 40, ui_noalign, "what", "What");   /* 4 */
   ui_out_table_body (current_uiout);

   ALL_SKIPLIST_ENTRIES (e)
     {
       struct cleanup *entry_chain;

       QUIT;
       if (arg != NULL && !number_is_in_list (arg, e->number))
 	continue;

       entry_chain = make_cleanup_ui_out_tuple_begin_end (current_uiout,
 							 "blklst-entry");
       ui_out_field_int (current_uiout, "number", e->number);             /* 1 */

       if (e->function_name != NULL)
 	ui_out_field_string (current_uiout, "type", "function");         /* 2 */
       else if (e->filename != NULL)
 	ui_out_field_string (current_uiout, "type", "file");             /* 2 */
       else
 	internal_error (__FILE__, __LINE__, _("\
 Skiplist entry should have either a filename or a function name."));

       if (e->enabled)
 	ui_out_field_string (current_uiout, "enabled", "y");             /* 3 */
       else
 	ui_out_field_string (current_uiout, "enabled", "n");             /* 3 */

       if (e->function_name != NULL)
 	ui_out_field_string (current_uiout, "what", e->function_name);	 /* 4 */
       else if (e->filename != NULL)
 	ui_out_field_string (current_uiout, "what", e->filename);	 /* 4 */

       ui_out_text (current_uiout, "\n");
       do_cleanups (entry_chain);
     }

   do_cleanups (tbl_chain);
 }

 static void
 skip_enable_command (char *arg, int from_tty)
 {
   struct skiplist_entry *e;
   int found = 0;

   ALL_SKIPLIST_ENTRIES (e)
     if (arg == NULL || number_is_in_list (arg, e->number))
       {
         e->enabled = 1;
         found = 1;
       }

   if (!found)
     error (_("No skiplist entries found with number %s."), arg);
 }

 static void
 skip_disable_command (char *arg, int from_tty)
 {
   struct skiplist_entry *e;
   int found = 0;

   ALL_SKIPLIST_ENTRIES (e)
     if (arg == NULL || number_is_in_list (arg, e->number))
       {
 	e->enabled = 0;
         found = 1;
       }

   if (!found)
     error (_("No skiplist entries found with number %s."), arg);
 }

 static void
 skip_delete_command (char *arg, int from_tty)
 {
   struct skiplist_entry *e, *temp, *b_prev;
   int found = 0;

   b_prev = 0;
   ALL_SKIPLIST_ENTRIES_SAFE (e, temp)
     if (arg == NULL || number_is_in_list (arg, e->number))
       {
 	if (b_prev != NULL)
 	  b_prev->next = e->next;
 	else
 	  skiplist_entry_chain = e->next;

 	xfree (e->function_name);
 	xfree (e->filename);
 	xfree (e);
         found = 1;
       }
     else
       {
 	b_prev = e;
       }

   if (!found)
     error (_("No skiplist entries found with number %s."), arg);
 }

 /* Create a skiplist entry for the given function NAME and add it to the
    list.  */

 static void
 skip_function (const char *name)
 {
   struct skiplist_entry *e = XZALLOC (struct skiplist_entry);

   e->enabled = 1;
   e->function_name = xstrdup (name);

   add_skiplist_entry (e);

   printf_filtered (_("Function %s will be skipped when stepping.\n"), name);
 }

 /* Add the given skiplist entry to our list, and set the entry's number.  */

 static void
 add_skiplist_entry (struct skiplist_entry *e)
 {
   struct skiplist_entry *e1;

   e->number = ++skiplist_entry_count;

   /* Add to the end of the chain so that the list of
      skiplist entries will be in numerical order.  */

   e1 = skiplist_entry_chain;
   if (e1 == NULL)
     skiplist_entry_chain = e;
   else
     {
       while (e1->next)
 	e1 = e1->next;
       e1->next = e;
     }
 }


 /* See skip.h.  */

 int
 function_name_is_marked_for_skip (const char *function_name,
 				  const struct symtab_and_line *function_sal)
 {
   int searched_for_fullname = 0;
   const char *fullname = NULL;
   struct skiplist_entry *e;

   if (function_name == NULL)
     return 0;

   ALL_SKIPLIST_ENTRIES (e)
     {
       if (!e->enabled)
 	continue;

       /* Does the pc we're stepping into match e's stored pc? */
       if (e->function_name != NULL
 	  && strcmp_iw (function_name, e->function_name) == 0)
 	return 1;

       if (e->filename != NULL)
 	{
 	  /* Check first sole SYMTAB->FILENAME.  It does not need to be
 	     a substring of symtab_to_fullname as it may contain "./" etc.  */
 	  if (function_sal->symtab != NULL
 	      && compare_filenames_for_search (function_sal->symtab->filename,
 					       e->filename))
 	    return 1;

 	  /* Before we invoke realpath, which can get expensive when many
 	     files are involved, do a quick comparison of the basenames.  */
 	  if (!basenames_may_differ
 	      && (function_sal->symtab == NULL
 	          || filename_cmp (lbasename (function_sal->symtab->filename),
 				   lbasename (e->filename)) != 0))
 	    continue;

 	  /* Get the filename corresponding to this FUNCTION_SAL, if we haven't
 	     yet.  */
 	  if (!searched_for_fullname)
 	    {
 	      if (function_sal->symtab != NULL)
 		fullname = symtab_to_fullname (function_sal->symtab);
 	      searched_for_fullname = 1;
 	    }
 	  if (fullname != NULL
 	      && compare_filenames_for_search (fullname, e->filename))
 	    return 1;
 	}
     }

   return 0;
 }

 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern initialize_file_ftype _initialize_step_skip;

 void
 _initialize_step_skip (void)
 {
   static struct cmd_list_element *skiplist = NULL;
   struct cmd_list_element *c;

   skiplist_entry_chain = 0;
   skiplist_entry_count = 0;

   add_prefix_cmd ("skip", class_breakpoint, skip_function_command, _("\
 Ignore a function while stepping.\n\
 Usage: skip [FUNCTION NAME]\n\
 If no function name is given, ignore the current function."),
                   &skiplist, "skip ", 1, &cmdlist);

   c = add_cmd ("file", class_breakpoint, skip_file_command, _("\
 Ignore a file while stepping.\n\
 Usage: skip file [FILENAME]\n\
 If no filename is given, ignore the current file."),
 	       &skiplist);
   set_cmd_completer (c, filename_completer);

   c = add_cmd ("function", class_breakpoint, skip_function_command, _("\
 Ignore a function while stepping.\n\
 Usage: skip function [FUNCTION NAME]\n\
 If no function name is given, skip the current function."),
 	       &skiplist);
   set_cmd_completer (c, location_completer);

   add_cmd ("enable", class_breakpoint, skip_enable_command, _("\
 Enable skip entries.  You can specify numbers (e.g. \"skip enable 1 3\"), \
 ranges (e.g. \"skip enable 4-8\"), or both (e.g. \"skip enable 1 3 4-8\").\n\n\
 If you don't specify any numbers or ranges, we'll enable all skip entries.\n\n\
 Usage: skip enable [NUMBERS AND/OR RANGES]"),
 	   &skiplist);

   add_cmd ("disable", class_breakpoint, skip_disable_command, _("\
 Disable skip entries.  You can specify numbers (e.g. \"skip disable 1 3\"), \
 ranges (e.g. \"skip disable 4-8\"), or both (e.g. \"skip disable 1 3 4-8\").\n\n\
 If you don't specify any numbers or ranges, we'll disable all skip entries.\n\n\
 Usage: skip disable [NUMBERS AND/OR RANGES]"),
 	   &skiplist);

   add_cmd ("delete", class_breakpoint, skip_delete_command, _("\
 Delete skip entries.  You can specify numbers (e.g. \"skip delete 1 3\"), \
 ranges (e.g. \"skip delete 4-8\"), or both (e.g. \"skip delete 1 3 4-8\").\n\n\
 If you don't specify any numbers or ranges, we'll delete all skip entries.\n\n\
 Usage: skip delete [NUMBERS AND/OR RANGES]"),
            &skiplist);

   add_info ("skip", skip_info, _("\
 Display the status of skips.  You can specify numbers (e.g. \"skip info 1 3\"), \
 ranges (e.g. \"skip info 4-8\"), or both (e.g. \"skip info 1 3 4-8\").\n\n\
 If you don't specify any numbers or ranges, we'll show all skips.\n\n\
 Usage: skip info [NUMBERS AND/OR RANGES]\n\
 The \"Type\" column indicates one of:\n\
 \tfile        - ignored file\n\
 \tfunction    - ignored function"));
 }
	/* Skipping uninteresting files and functions while stepping.

	Copyright (C) 2011-2013 Free Software Foundation, Inc.

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program. If not, see <http://www.gnu.org/licenses/>. */

	#include "defs.h"
	#include "skip.h"
	#include "value.h"
	#include "valprint.h"
	#include "ui-out.h"
	#include "gdb_string.h"
	#include "symtab.h"
	#include "gdbcmd.h"
	#include "command.h"
	#include "completer.h"
	#include "stack.h"
	#include "cli/cli-utils.h"
	#include "arch-utils.h"
	#include "linespec.h"
	#include "objfiles.h"
	#include "exceptions.h"
	#include "breakpoint.h" /* for get_sal_arch () */
	#include "source.h"
	#include "filenames.h"

	struct skiplist_entry
	{
	int number;

	/* NULL if this isn't a skiplist entry for an entire file.
	The skiplist entry owns this pointer. */
	char *filename;

	/* The name of the marked-for-skip function, if this is a skiplist
	entry for a function.
	The skiplist entry owns this pointer. */
	char *function_name;

	int enabled;

	struct skiplist_entry *next;
	};

	static void add_skiplist_entry (struct skiplist_entry *e);
	static void skip_function (const char *name);

	static struct skiplist_entry *skiplist_entry_chain;
	static int skiplist_entry_count;

	#define ALL_SKIPLIST_ENTRIES(E) \
	for (E = skiplist_entry_chain; E; E = E->next)

	#define ALL_SKIPLIST_ENTRIES_SAFE(E,TMP) \
	for (E = skiplist_entry_chain; \
	E ? (TMP = E->next, 1) : 0; \
	E = TMP)

	static void
	skip_file_command (char *arg, int from_tty)
	{
	struct skiplist_entry *e;
	struct symtab *symtab;
	const char *filename = NULL;

	/* If no argument was given, try to default to the last
	displayed codepoint. */
	if (arg == NULL)
	{
	symtab = get_last_displayed_symtab ();
	if (symtab == NULL)
	error (_("No default file now."));

	/* It is not a typo, symtab_to_filename_for_display woule be needlessly
	ambiguous. */
	filename = symtab_to_fullname (symtab);
	}
	else
	{
	symtab = lookup_symtab (arg);
	if (symtab == NULL)
	{
	fprintf_filtered (gdb_stderr, _("No source file named %s.\n"), arg);
	if (!nquery (_("\
	Ignore file pending future shared library load? ")))
	return;
	}
	/* Do not use SYMTAB's filename, later loaded shared libraries may match
	given ARG but not SYMTAB's filename. */
	filename = arg;
	}

	e = XZALLOC (struct skiplist_entry);
	e->filename = xstrdup (filename);
	e->enabled = 1;

	add_skiplist_entry (e);

	printf_filtered (_("File %s will be skipped when stepping.\n"), filename);
	}

	static void
	skip_function_command (char *arg, int from_tty)
	{
	const char *name = NULL;

	/* Default to the current function if no argument is given. */
	if (arg == NULL)
	{
	CORE_ADDR pc;

	if (!last_displayed_sal_is_valid ())
	error (_("No default function now."));

	pc = get_last_displayed_addr ();
	if (!find_pc_partial_function (pc, &name, NULL, NULL))
	{
	error (_("No function found containing current program point %s."),
	paddress (get_current_arch (), pc));
	}
	skip_function (name);
	}
	else
	{
	if (lookup_symbol (arg, NULL, VAR_DOMAIN, NULL) == NULL)
	{
	fprintf_filtered (gdb_stderr,
	_("No function found named %s.\n"), arg);

	if (nquery (_("\
	Ignore function pending future shared library load? ")))
	{
	/* Add the unverified skiplist entry. */
	skip_function (arg);
	}
	return;
	}

	skip_function (arg);
	}
	}

	static void
	skip_info (char *arg, int from_tty)
	{
	struct skiplist_entry *e;
	int num_printable_entries = 0;
	struct value_print_options opts;
	struct cleanup *tbl_chain;

	get_user_print_options (&opts);

	/* Count the number of rows in the table and see if we need space for a
	64-bit address anywhere. */
	ALL_SKIPLIST_ENTRIES (e)
	if (arg == NULL \|\| number_is_in_list (arg, e->number))
	num_printable_entries++;

	if (num_printable_entries == 0)
	{
	if (arg == NULL)
	ui_out_message (current_uiout, 0, _("\
	Not skipping any files or functions.\n"));
	else
	ui_out_message (current_uiout, 0,
	_("No skiplist entries found with number %s.\n"), arg);

	return;
	}

	tbl_chain = make_cleanup_ui_out_table_begin_end (current_uiout, 4,
	num_printable_entries,
	"SkiplistTable");

	ui_out_table_header (current_uiout, 7, ui_left, "number", "Num"); /* 1 */
	ui_out_table_header (current_uiout, 14, ui_left, "type", "Type"); /* 2 */
	ui_out_table_header (current_uiout, 3, ui_left, "enabled", "Enb"); /* 3 */
	ui_out_table_header (current_uiout, 40, ui_noalign, "what", "What"); /* 4 */
	ui_out_table_body (current_uiout);

	ALL_SKIPLIST_ENTRIES (e)
	{
	struct cleanup *entry_chain;

	QUIT;
	if (arg != NULL && !number_is_in_list (arg, e->number))
	continue;

	entry_chain = make_cleanup_ui_out_tuple_begin_end (current_uiout,
	"blklst-entry");
	ui_out_field_int (current_uiout, "number", e->number); /* 1 */

	if (e->function_name != NULL)
	ui_out_field_string (current_uiout, "type", "function"); /* 2 */
	else if (e->filename != NULL)
	ui_out_field_string (current_uiout, "type", "file"); /* 2 */
	else
	internal_error (__FILE__, __LINE__, _("\
	Skiplist entry should have either a filename or a function name."));

	if (e->enabled)
	ui_out_field_string (current_uiout, "enabled", "y"); /* 3 */
	else
	ui_out_field_string (current_uiout, "enabled", "n"); /* 3 */

	if (e->function_name != NULL)
	ui_out_field_string (current_uiout, "what", e->function_name); /* 4 */
	else if (e->filename != NULL)
	ui_out_field_string (current_uiout, "what", e->filename); /* 4 */

	ui_out_text (current_uiout, "\n");
	do_cleanups (entry_chain);
	}

	do_cleanups (tbl_chain);
	}

	static void
	skip_enable_command (char *arg, int from_tty)
	{
	struct skiplist_entry *e;
	int found = 0;

	ALL_SKIPLIST_ENTRIES (e)
	if (arg == NULL \|\| number_is_in_list (arg, e->number))
	{
	e->enabled = 1;
	found = 1;
	}

	if (!found)
	error (_("No skiplist entries found with number %s."), arg);
	}

	static void
	skip_disable_command (char *arg, int from_tty)
	{
	struct skiplist_entry *e;
	int found = 0;

	ALL_SKIPLIST_ENTRIES (e)
	if (arg == NULL \|\| number_is_in_list (arg, e->number))
	{
	e->enabled = 0;
	found = 1;
	}

	if (!found)
	error (_("No skiplist entries found with number %s."), arg);
	}

	static void
	skip_delete_command (char *arg, int from_tty)
	{
	struct skiplist_entry e, temp, *b_prev;
	int found = 0;

	b_prev = 0;
	ALL_SKIPLIST_ENTRIES_SAFE (e, temp)
	if (arg == NULL \|\| number_is_in_list (arg, e->number))
	{
	if (b_prev != NULL)
	b_prev->next = e->next;
	else
	skiplist_entry_chain = e->next;

	xfree (e->function_name);
	xfree (e->filename);
	xfree (e);
	found = 1;
	}
	else
	{
	b_prev = e;
	}

	if (!found)
	error (_("No skiplist entries found with number %s."), arg);
	}

	/* Create a skiplist entry for the given function NAME and add it to the
	list. */

	static void
	skip_function (const char *name)
	{
	struct skiplist_entry *e = XZALLOC (struct skiplist_entry);

	e->enabled = 1;
	e->function_name = xstrdup (name);

	add_skiplist_entry (e);

	printf_filtered (_("Function %s will be skipped when stepping.\n"), name);
	}

	/* Add the given skiplist entry to our list, and set the entry's number. */

	static void
	add_skiplist_entry (struct skiplist_entry *e)
	{
	struct skiplist_entry *e1;

	e->number = ++skiplist_entry_count;

	/* Add to the end of the chain so that the list of
	skiplist entries will be in numerical order. */

	e1 = skiplist_entry_chain;
	if (e1 == NULL)
	skiplist_entry_chain = e;
	else
	{
	while (e1->next)
	e1 = e1->next;
	e1->next = e;
	}
	}


	/* See skip.h. */

	int
	function_name_is_marked_for_skip (const char *function_name,
	const struct symtab_and_line *function_sal)
	{
	int searched_for_fullname = 0;
	const char *fullname = NULL;
	struct skiplist_entry *e;

	if (function_name == NULL)
	return 0;

	ALL_SKIPLIST_ENTRIES (e)
	{
	if (!e->enabled)
	continue;

	/* Does the pc we're stepping into match e's stored pc? */
	if (e->function_name != NULL
	&& strcmp_iw (function_name, e->function_name) == 0)
	return 1;

	if (e->filename != NULL)
	{
	/* Check first sole SYMTAB->FILENAME. It does not need to be
	a substring of symtab_to_fullname as it may contain "./" etc. */
	if (function_sal->symtab != NULL
	&& compare_filenames_for_search (function_sal->symtab->filename,
	e->filename))
	return 1;

	/* Before we invoke realpath, which can get expensive when many
	files are involved, do a quick comparison of the basenames. */
	if (!basenames_may_differ
	&& (function_sal->symtab == NULL
	\|\| filename_cmp (lbasename (function_sal->symtab->filename),
	lbasename (e->filename)) != 0))
	continue;

	/* Get the filename corresponding to this FUNCTION_SAL, if we haven't
	yet. */
	if (!searched_for_fullname)
	{
	if (function_sal->symtab != NULL)
	fullname = symtab_to_fullname (function_sal->symtab);
	searched_for_fullname = 1;
	}
	if (fullname != NULL
	&& compare_filenames_for_search (fullname, e->filename))
	return 1;
	}
	}

	return 0;
	}

	/* Provide a prototype to silence -Wmissing-prototypes. */
	extern initialize_file_ftype _initialize_step_skip;

	void
	_initialize_step_skip (void)
	{
	static struct cmd_list_element *skiplist = NULL;
	struct cmd_list_element *c;

	skiplist_entry_chain = 0;
	skiplist_entry_count = 0;

	add_prefix_cmd ("skip", class_breakpoint, skip_function_command, _("\
	Ignore a function while stepping.\n\
	Usage: skip [FUNCTION NAME]\n\
	If no function name is given, ignore the current function."),
	&skiplist, "skip ", 1, &cmdlist);

	c = add_cmd ("file", class_breakpoint, skip_file_command, _("\
	Ignore a file while stepping.\n\
	Usage: skip file [FILENAME]\n\
	If no filename is given, ignore the current file."),
	&skiplist);
	set_cmd_completer (c, filename_completer);

	c = add_cmd ("function", class_breakpoint, skip_function_command, _("\
	Ignore a function while stepping.\n\
	Usage: skip function [FUNCTION NAME]\n\
	If no function name is given, skip the current function."),
	&skiplist);
	set_cmd_completer (c, location_completer);

	add_cmd ("enable", class_breakpoint, skip_enable_command, _("\
	Enable skip entries. You can specify numbers (e.g. \"skip enable 1 3\"), \
	ranges (e.g. \"skip enable 4-8\"), or both (e.g. \"skip enable 1 3 4-8\").\n\n\
	If you don't specify any numbers or ranges, we'll enable all skip entries.\n\n\
	Usage: skip enable [NUMBERS AND/OR RANGES]"),
	&skiplist);

	add_cmd ("disable", class_breakpoint, skip_disable_command, _("\
	Disable skip entries. You can specify numbers (e.g. \"skip disable 1 3\"), \
	ranges (e.g. \"skip disable 4-8\"), or both (e.g. \"skip disable 1 3 4-8\").\n\n\
	If you don't specify any numbers or ranges, we'll disable all skip entries.\n\n\
	Usage: skip disable [NUMBERS AND/OR RANGES]"),
	&skiplist);

	add_cmd ("delete", class_breakpoint, skip_delete_command, _("\
	Delete skip entries. You can specify numbers (e.g. \"skip delete 1 3\"), \
	ranges (e.g. \"skip delete 4-8\"), or both (e.g. \"skip delete 1 3 4-8\").\n\n\
	If you don't specify any numbers or ranges, we'll delete all skip entries.\n\n\
	Usage: skip delete [NUMBERS AND/OR RANGES]"),
	&skiplist);

	add_info ("skip", skip_info, _("\
	Display the status of skips. You can specify numbers (e.g. \"skip info 1 3\"), \
	ranges (e.g. \"skip info 4-8\"), or both (e.g. \"skip info 1 3 4-8\").\n\n\
	If you don't specify any numbers or ranges, we'll show all skips.\n\n\
	Usage: skip info [NUMBERS AND/OR RANGES]\n\
	The \"Type\" column indicates one of:\n\
	\tfile - ignored file\n\
	\tfunction - ignored function"));
	}