Initial revision

2 files changed, 306 insertions, 0 deletions

diff --git a/libshouldbeinlibc/options.c b/libshouldbeinlibc/options.c
new file mode 100644
index 00000000..e0c4b0c5
--- /dev/null
+++ b/libshouldbeinlibc/options.c
@@ -0,0 +1,227 @@
+/* Hierarchial options parsing, layered over getopt
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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 2, or (at
+   your option) any later version.
+
+   The GNU Hurd 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>		/* for CHAR_BIT */
+#include <getopt.h>
+#include <cthreads.h>
+#include <options.h>
+
+#define EOF (-1)
+
+/* The number of bits we steal in a long-option value for our own use.  */
+#define GROUP_BITS CHAR_BIT
+
+/* The number of bits available for the user value.  */
+#define USER_BITS ((sizeof ((struct option *)0)->val * CHAR_BIT) - GROUP_BITS)
+#define USER_MASK ((1 << USER_BITS) - 1)
+
+/* ---------------------------------------------------------------- */
+
+/* Returns the offset into LONG_OPTIONS of a long option with called NAME, or
+   -1 if none is found.  Passing NULL as NAME will return the number of
+   options.  */
+static int
+find_long_option (struct option *long_options, const char *name)
+{
+  struct option *l = long_options;
+  while (l->name != NULL)
+    if (name != NULL && strcmp (l->name, name) == 0)
+      return l - long_options;
+    else
+      l++;
+  if (name == NULL)
+    return l - long_options;
+  else
+    return -1;
+}
+
+/* ---------------------------------------------------------------- */
+
+/* Used to regulate access to the getopt routines, which are non-reentrant.  */
+static struct mutex getopt_lock = MUTEX_INITIALIZER;
+
+/* Parse the options strings in ARGC & ARGV according to the options in
+   OPTIONS.  FLAGS is one of the OPTIONS_ flags above.  If OPTIND is
+   non-NULL, the index in ARGV of the first unparsed option is returned in
+   it.  If an unknown option is present, EINVAL is returned; if some parser
+   routine returned a non-zero value, it is returned; otherwise 0 is
+   returned.  */
+error_t
+options_parse (struct options *options,
+	       int argc, char **argv,
+	       unsigned flags, int *arg_index)
+{
+  int opt;
+  struct options *o;
+  /* SHORT_OPTS is the getopt short options string for the union of all the
+     groups of options.  */
+  char *short_opts;
+  /* GROUP_SHORT_STARTS is an array pointing to the part of SHORT_OPTS
+     corresponding to each different group of options.  We use it to
+     determine from which groupa particular short options is from.  */
+  char **group_short_starts;
+  /* LONG_OPTS is the array of getop long option structures for the union of
+     all the groups of options.  */
+  struct option *long_opts;
+  error_t err = 0;
+
+  /* Find the merged set of short options.  */
+  {
+    char *short_end;
+    int short_len = (flags & OPTIONS_PARSE_ARGS) ? 1 : 0;
+    int num_groups = 0, group;
+
+    /* Find the (maximum) amount of space necessary to store all combined
+       short options, plus the number of options groups in the chain.  */
+    for (o = options; o != NULL; o = o->parent)
+      {
+	num_groups++;
+	short_len += strlen (o->short_options);
+      }
+
+    short_opts = short_end = alloca (short_len + 1);
+    if (flags & OPTIONS_PARSE_ARGS)
+      *short_end++ = '-';	/* Tell getopt we want to do this.  */
+    *short_end = '\0';
+
+    group_short_starts = alloca (num_groups * sizeof (char *));
+
+    for (o = options, group = 0; o != NULL; o = o->parent, group++)
+      {
+	char *s;
+
+	group_short_starts[group] = short_end;
+
+	for (s = o->short_options; *s != '\0'; s++)
+	  /* We add *S to our set of short options only if it hasn't already
+	     been added by some previous group.  */
+	  if (*s != ':' && !index (short_opts, *s))
+	    {
+	      *short_end++ = *s;
+	      /* Copy all the colon modifiers following the option.  */
+	      while (s[1] == ':')
+		*short_end++ = *++s;
+	      *short_end = '\0';
+	    }
+      }
+  }
+
+  /* Find the merged set of long options, with keys appropiately prefixed. */
+  {
+    struct option *long_end;
+    int group;
+    int long_len = 0;
+
+    for (o = options; o != NULL; o = o->parent)
+      long_len += find_long_option (o->long_options, NULL);
+
+    long_opts = long_end = alloca ((long_len + 1) * sizeof (struct option));
+    long_end->name = NULL;
+
+    /* Note that GROUP starts at 1 because 0 is for short options.  */
+    for (o = options, group = 1; o != NULL; o = o->parent, group++)
+      {
+	struct option *l;
+	for (l = o->long_options; l->name != NULL; l++)
+	  /* Only add the long option L if it hasn't been already.  */
+	  if (find_long_option (long_opts, l->name) < 0)
+	    {
+	      *long_end = *l;
+	      if (long_end->flag == NULL)
+		/* In the case where a long option returns a key from getopt,
+		   we add a disambiguating code to all the user's values
+		   (which is removed before we actually call the function to
+		   parse the value); this means that the user loses use of
+		   the high 8 bits in all his values (the sign of the lower
+		   bits is preserved however)...  */
+		long_end->val = (l->val & USER_MASK) + (group << USER_BITS);
+	      /* Keep the LONG_OPTS list terminated.  */
+	      (++long_end)->name = NULL;
+	    }
+      }
+  }
+
+  /* Getopt is (currently) non-reentrant.  */
+  mutex_lock (&getopt_lock);
+
+  if (flags & OPTIONS_PRINT_ERRS)
+    opterr = 1;			/* Print error messages.  */
+  else
+    {
+      opterr = 0;
+      if (!(flags & OPTIONS_SKIP_ARG0))
+	/* getopt always skips ARGV[0], so we have to fake it out.  As long
+	   as opterr is 0, then it shouldn't actually try to access it.  */
+	argv--;
+    }
+
+  /* Now use getopt on our coalesced options lists.  */
+  while ((opt = getopt_long (argc, argv, short_opts, long_opts, 0)) != EOF)
+    {
+      int group = opt >> USER_BITS;
+
+      err = EINVAL;		/* until otherwise asserted */
+
+      if (opt == 1)
+	/* A non-option argument; try each parser in turn.  */
+	for (o = options; o != NULL && err == EINVAL; o = o->parent)
+	  err = (*o->parser)(opt, optarg);
+      else if (group == 0)
+	/* A short option.  */
+	{
+	  /* By comparing OPT's position in SHORT_OPTS to the various
+	     starting positions in GROUP_SHORT_STARTS, we can determine which
+	     group OPT came from.  */
+	  char *short_index = index (short_opts, opt);
+	  if (short_index)
+	    for (o = options, group = 0; o != NULL; o = o->parent, group++)
+	      if (o->parent == NULL
+		  || group_short_starts[group + 1] > short_index)
+		{
+		  err = (*o->parser)(opt, optarg);
+		  break;
+		}
+	}
+      else
+	/* A long option.  */
+	for (o = options; o != NULL; o = o->parent)
+	  if (--group == 0)
+	    {
+	      /* We use shifts instead of masking for extracting the user value
+		 in order to preserve the sign.  */
+	      err = (*o->parser)(((opt << GROUP_BITS) >> GROUP_BITS), optarg);
+	      break;
+	    }
+
+      if (err)
+	break;
+    }
+
+  if (arg_index != NULL)
+    *arg_index = optind;
+
+  mutex_unlock (&getopt_lock);
+
+  return err;
+}
diff --git a/libshouldbeinlibc/options.h b/libshouldbeinlibc/options.h
new file mode 100644
index 00000000..6ac15c63
--- /dev/null
+++ b/libshouldbeinlibc/options.h
@@ -0,0 +1,79 @@
+/* Hierarchial options parsing, layered over getopt
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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 2, or (at
+   your option) any later version.
+
+   The GNU Hurd 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#ifndef __OPTIONS_H__
+#define __OPTIONS_H__
+
+#include <errno.h>
+#include <getopt.h>
+
+/* An options structure contains a set of getopt options declarations, a
+   function to deal with getting one, and an optional pointer to another
+   options structure.  When actually parsing options, getopt is called with
+   the union of all the options structures chained together through their
+   PARENT pointers, with conflicts being resolved in favor of the first
+   occurance in the chain.  */
+struct options
+{
+  /* The getopt-style short options string for this group of options.  */
+  char *short_options;
+  /* An array of getopt-style long-options structures.  */
+  struct option *long_options;
+
+  /* What to do with an option from this structure.  KEY is either the short
+     option letter, or the final member of the long-option entry, as returned
+     by getopt, and ARG is the value of OPTARG.  If a non-zero value is
+     returned, then parsing is stopped immediately, and that value is
+     returned from options_parse().  */
+  error_t (*parser)(int key, char *arg);
+
+  /* The next member in this options chain.  */
+  struct options *parent;
+};
+
+/* Flags for options_parse:  */
+
+/* Ignore the first element of ARGV.  Useful for program command lines.  */
+#define OPTIONS_SKIP_ARG0    0x1
+
+/* Print error messages for unknown options to stderr; if this flag is set,
+   OPTIONS_SKIP_ARG0 is ignored, as ARGV[0] is used as the program name in
+   the error messages.  */
+#define OPTIONS_PRINT_ERRS   0x2
+
+/* Parse non-option args as well, similarly to getopt, by calling the parse
+   function with a key of 1, and the actual arg as the value.  Since it's
+   impossible to know which parse function wants to handle it, each one is
+   called in turn, until one returns 0 or an error other than EINVAL.  */
+#define OPTIONS_PARSE_ARGS   0x4
+
+
+/* Parse the options strings in ARGC & ARGV according to the options in
+   OPTIONS.  FLAGS is one of the OPTIONS_ flags above.  If ARG_INDEX is
+   non-NULL, the index in ARGV of the first unparsed option is returned in
+   it.  If an unknown option is present, EINVAL is returned; if some parser
+   routine returned a non-zero value, it is returned; otherwise 0 is
+   returned.  */
+error_t options_parse (struct options *options, int argc, char **argv,
+		       unsigned flags, int *arg_index);
+
+#endif /* __OPTIONS_H__ */