gnu1987/emacs18.41/gdb/command.c

/* Library for reading command lines and decoding commands.
   Copyright (C) 1986 Free Software Foundation, Inc.

		       NO WARRANTY

  BECAUSE THIS PROGRAM IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
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  4. You may not copy, sublicense, distribute or transfer this program
except as expressly provided under this License Agreement.  Any attempt
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your rights to use the program under this License agreement shall be
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  5. If you wish to incorporate parts of this program into other free
programs whose distribution conditions are different, write to the Free
Software Foundation at 1000 Mass Ave, Cambridge, MA 02138.  We have not yet
worked out a simple rule that can be stated here, but we will often permit
this.  We will be guided by the two goals of preserving the free status of
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In other words, you are welcome to use, share and improve this program.
You are forbidden to forbid anyone else to use, share and improve
what you give them.   Help stamp out software-hoarding!  */


#include "command.h"
#include <stdio.h>

static char *savestring ();

/* Add element named NAME to command list *LIST.
   FUN should be the function to execute the command;
   it will get a character string as argument, with leading
   and trailing blanks already eliminated.

   DOC is a documentation string for the command.
   Its first line should be a complete sentence.
   It should start with ? for a command that is an abbreviation
   or with * for a command that most users don't need to know about.  */

struct cmd_list_element *
add_cmd (name, class, fun, doc, list)
     char *name;
     int class;
     void (*fun) ();
     char *doc;
     struct cmd_list_element **list;
{
  register struct cmd_list_element *c = (struct cmd_list_element *) xmalloc (sizeof (struct cmd_list_element));

  delete_cmd (name, list);
  c->next = *list;
  c->name = savestring (name, strlen (name));
  c->class = class;
  c->function = fun;
  c->doc = doc;
  c->prefixlist = 0;
  c->allow_unknown = 0;
  c->abbrev_flag = 0;
  c->aux = 0;
  *list = c;
  return c;
}

struct cmd_list_element *
add_alias_cmd (name, oldname, class, abbrev_flag, list)
     char *name;
     char *oldname;
     int class;
     int abbrev_flag;
     struct cmd_list_element **list;
{
  register struct cmd_list_element *old
    = lookup_cmd (&oldname, *list, 0, 1);
  register struct cmd_list_element *c;

  if (old == 0)
    {
      delete_cmd (name, list);
      return 0;
    }

  c = add_cmd (name, class, old->function, old->doc, list);
  c->prefixlist = old->prefixlist;
  c->prefixname = old->prefixname;
  c->allow_unknown = old->allow_unknown;
  c->abbrev_flag = abbrev_flag;
  c->aux = old->aux;
  return c;
}

/* Like add_prefix_cmd but adds an element for a command prefix:
   a name that should be followed by a subcommand to be looked up
   in another command list.  PREFIXLIST should be the address
   of the variable containing that list.  */

struct cmd_list_element *
add_prefix_cmd (name, class, fun, doc, prefixlist, prefixname,
		allow_unknown, list)
     char *name;
     int class;
     void (*fun) ();
     char *doc;
     struct cmd_list_element **prefixlist;
     char *prefixname;
     int allow_unknown;
     struct cmd_list_element **list;
{
  register struct cmd_list_element *c = add_cmd (name, class, fun, doc, list);
  c->prefixlist = prefixlist;
  c->prefixname = prefixname;
  c->allow_unknown = allow_unknown;
  return c;
}

/* Remove the command named NAME from the command list.  */

void
delete_cmd (name, list)
     char *name;
     struct cmd_list_element **list;
{
  register struct cmd_list_element *c;

  while (*list && !strcmp ((*list)->name, name))
    {
      *list = (*list)->next;
    }

  if (*list)
    for (c = *list; c->next;)
      {
	if (!strcmp (c->next->name, name))
	  c->next = c->next->next;
	else
	  c = c->next;
      }
}

/* Implement a help command on command list LIST.
   COMMAND is the argument given (a command from the list to document)
   or zero for no arg (describe briefly all the commands in the list).
   CMDTYPE is a string to use in the error message if command COMMAND
   is not found in the list.  */

/* CLASS should be -1 to list all commands in LIST,
   or a nonnegative class number value to list just commands in that class,
   or -2 to list the classes themselves.  */

void
help_cmd (command, list, cmdtype, class, stream)
     char *command;
     struct cmd_list_element *list;
     char *cmdtype;
     int class;
     FILE *stream;
{
  register struct cmd_list_element *c;
  register char *p;
  register int ncmds;
  struct cmdvec { struct cmd_list_element *cmd; int class; };
  register struct cmdvec *cmdvec;
  char *cmdtype1, *cmdtype2;
  int len;

  if (command)
    {
      c = lookup_cmd (&command, list, cmdtype, 0);
      if (c == 0)
	return;

      /* There are three cases here.
	 If c->prefixlist is nonzer, we have a prefix command.
	 Print its documentation, then list its subcommands.

	 If c->function is nonzero, we really have a command.
	 Print its documentation and return.

	 If c->function is zero, we have a class name.
	 Print its documentation (as if it were a command)
	 and then set class to he number of this class
	 so that the commands in the class will be listed.  */

      p = c->doc;
      fprintf (stream, "%s\n", p);
      if (c->function != 0 && c->prefixlist == 0)
	return;
      fputc ('\n', stream);
      if (c->prefixlist)
	{
	  list = *c->prefixlist;
	  class = 0;
	  cmdtype = c->prefixname;
	}
      else
	class = c->class;
    }

  /* If CMDTYPE is "foo ", CMDTYPE1 gets " foo" and CMDTYPE2 gets "foo sub"  */
  len = strlen (cmdtype);
  cmdtype1 = (char *) alloca (len + 1);
  cmdtype1[0] = 0;
  cmdtype2 = (char *) alloca (len + 4);
  cmdtype2[0] = 0;
  if (len)
    {
      cmdtype1[0] = ' ';
      strncpy (cmdtype1 + 1, cmdtype, len - 1);
      cmdtype1[len] = 0;
      strncpy (cmdtype2, cmdtype, len - 1);
      strcpy (cmdtype2 + len - 1, " sub");
    }

  if (class == -2)
    fprintf (stream, "List of classes of %scommands:\n\n", cmdtype2);
  else
    fprintf (stream, "List of %scommands:\n\n", cmdtype2);

  for (c = list; c; c = c->next)
    {
      if (c->abbrev_flag == 0
	  && (class == -1	/* Listing all */
	      || (c->class == class && c->function != 0) /* Listing one class */
	      || (class == -2 && c->function == 0)))	/* Listing the classes */
	{
	  fprintf (stream, "%s -- ", c->name);
	  /* Print just first line of documentation.  */
	  p = c->doc;
	  while (*p && *p != '\n') p++;
	  fwrite (c->doc, 1, p - c->doc, stream);
	  fputc ('\n', stream);
	}
    }

  if (class == -2)
    fprintf (stream, "\n\
Type \"help%s\" followed by a class name for a list of commands in that class.",
	     cmdtype1);

  fprintf (stream, "\n\
Type \"help%s\" followed by %scommand name for full documentation.\n\
Command name abbreviations are allowed if unambiguous.\n",
	   cmdtype1, cmdtype2);
}

/* Look up the contents of *LINE as a command in the command list LIST.
   LIST is a chain of struct cmd_list_element's.
   If it is found, return the struct cmd_list_element for that command
   and update *LINE to point after the command name, at the first argument.
   If not found, call error if ALLOW_UNKNOWN is zero
   otherwise (or if error returns) return zero.
   Call error if specified command is ambiguous,
   unless ALLOW_UNKNOWN is negative.
   CMDTYPE precedes the word "command" in the error message.  */

struct cmd_list_element *
lookup_cmd (line, list, cmdtype, allow_unknown)
     char **line;
     struct cmd_list_element *list;
     char *cmdtype;
     int allow_unknown;
{
  register char *p;
  register struct cmd_list_element *c, *found;
  int nfound;
  char ambbuf[100];

  /* Skip leading whitespace.  */

  while (**line == ' ' || **line == '\t')
    (*line)++;

  /* Clear out trailing whitespace.  */

  p = *line + strlen (*line);
  while (p != *line && (p[-1] == ' ' || p[-1] == '\t'))
    p--;
  *p = 0;

  /* Find end of command name.  */

  p = *line;
  while (*p == '-'
	 || (*p >= 'a' && *p <= 'z')
	 || (*p >= 'A' && *p <= 'Z')
	 || (*p >= '1' && *p <= '9'))
    {
      if (*p >= 'A' && *p <= 'Z')
	*p += 'a' - 'A';
      p++;
    }

  /* Look up the command name.
     If exact match, keep that.
     Otherwise, take command abbreviated, if unique.  */

  found = 0;
  nfound = 0;
  for (c = list; c; c = c->next)
    {
      if (!strncmp (*line, c->name, p - *line))
	{
	  found = c;
	  nfound++;
	  if (c->name[p - *line] == 0)
	    {
	      nfound = 1;
	      break;
	    }
	}
    }

  /* Report error for undefined command name.  */

  if (nfound != 1)
    {
      if (nfound > 1 && allow_unknown >= 0)
	{
	  *p = 0;
	  ambbuf[0] = 0;
	  for (c = list; c; c = c->next)
	    if (!strncmp (*line, c->name, p - *line))
	      {
		if (strlen (ambbuf) + strlen (c->name) + 6 < sizeof ambbuf)
		  {
		    if (strlen (ambbuf))
		      strcat (ambbuf, ", ");
		    strcat (ambbuf, c->name);
		  }
		else
		  {
		    strcat (ambbuf, "..");
		    break;
		  }
	      }
	  error ("Ambiguous %scommand \"%s\": %s.", cmdtype, *line, ambbuf);
	}
      else if (!allow_unknown)
	{
	  *p = 0;
	  error ("Undefined %scommand: \"%s\".", cmdtype, *line);
	}
      return 0;
    }

  /* Skip whitespace before the argument.  */

  while (*p == ' ' || *p == '\t') p++;
  *line = p;

  if (found->prefixlist && *p)
    {
      c = lookup_cmd (line, *found->prefixlist, found->prefixname,
		      found->allow_unknown);
      if (c)
	return c;
    }

  return found;
}

/* Make a copy of the string at PTR with SIZE characters
   (and add a null character at the end in the copy).
   Uses malloc to get the space.  Returns the address of the copy.  */

static char *
savestring (ptr, size)
     char *ptr;
     int size;
{
  register char *p = (char *) xmalloc (size + 1);
  bcopy (ptr, p, size);
  p[size] = 0;
  return p;
}