X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=ucw%2Fopt.c;h=1a94f7c0bd691042eef5f05d3e279653cd7cea3e;hb=84a25b8a8b5c99ef48dd63ca1078e22aa18ecab8;hp=454fbd94eded1acc91129e78fde2b93374382b25;hpb=9d24e18d51c569cd2cdfb61270d98af13ccfb21c;p=libucw.git

diff --git a/ucw/opt.c b/ucw/opt.c
index 454fbd94..1a94f7c0 100644
--- a/ucw/opt.c
+++ b/ucw/opt.c
@@ -1,7 +1,8 @@
 /*
- *	UCW Library -- Parsing of command line options
+ *	UCW Library -- Parsing of command-line options
  *
  *	(c) 2013 Jan Moskyto Matejka <mq@ucw.cz>
+ *	(c) 2014 Martin Mares <mj@ucw.cz>
  *
  *	This software may be freely distributed and used according to the terms
  *	of the GNU Lesser General Public License.
@@ -9,255 +10,131 @@
 
 #include <ucw/lib.h>
 #include <ucw/opt.h>
-#include <ucw/conf.h>
-#include <ucw/conf-internal.h>
-#include <ucw/fastbuf.h>
+#include <ucw/opt-internal.h>
 #include <ucw/stkstring.h>
 #include <ucw/strtonum.h>
 
 #include <alloca.h>
 #include <math.h>
 
-int opt_parsed_count = 0;
-int opt_conf_parsed_count = 0;
+static uns opt_default_value_flags[] = {
+    [OPT_CL_BOOL] = OPT_NO_VALUE,
+    [OPT_CL_STATIC] = OPT_MAYBE_VALUE,
+    [OPT_CL_SWITCH] = OPT_NO_VALUE,
+    [OPT_CL_INC] = OPT_NO_VALUE,
+    [OPT_CL_CALL] = 0,
+    [OPT_CL_USER] = 0,
+    [OPT_CL_SECTION] = 0,
+    [OPT_CL_HELP] = 0
+};
 
-static void opt_failure(const char * mesg, ...) FORMAT_CHECK(printf,1,2) NONRET;
-static void opt_failure(const char * mesg, ...) {
+void opt_failure(const char * mesg, ...) {
   va_list args;
   va_start(args, mesg);
   vfprintf(stderr, mesg, args);
-  fprintf(stderr, "\n");
-  opt_usage();
+  fprintf(stderr, "\nRun with --help for more information.\n");
   exit(OPT_EXIT_BAD_ARGS);
-  va_end(args);		// FIXME: Does this make a sense after exit()?
 }
 
-// FIXME: This could be an inline function, couldn't it?
-#define OPT_ADD_DEFAULT_ITEM_FLAGS(item, flags) \
-  do { \
-    if (item->letter >= 256) { \
-      if (flags & OPT_VALUE_FLAGS) /* FIXME: Redundant condition */ \
-	flags &= ~OPT_VALUE_FLAGS; \
-      flags |= OPT_REQUIRED_VALUE; \
-    } \
-    if (!(flags & OPT_VALUE_FLAGS) && \
-	(item->cls == OPT_CL_CALL || item->cls == OPT_CL_USER)) { \
-      fprintf(stderr, "You MUST specify some of the value flags for the %c/%s item.\n", item->letter, item->name); \
-      ASSERT(0); \
-    } \
-    else if (!(flags & OPT_VALUE_FLAGS)) /* FIXME: Streamline the conditions */ \
-      flags |= opt_default_value_flags[item->cls]; \
-  } while (0)
-// FIXME: Is this still useful? Isn't it better to use OPT_ADD_DEFAULT_ITEM_FLAGS during init?
-#define OPT_ITEM_FLAGS(item) ((item->flags & OPT_VALUE_FLAGS) ? item->flags : item->flags | opt_default_value_flags[item->cls])
-
-const struct opt_section * opt_section_root;
-
-#define FOREACHLINE(text) for (const char * begin = (text), * end = (text); (*end) && (end = strchrnul(begin, '\n')); begin = end+1)
-
-void opt_help_internal(const struct opt_section * help) {
-  int sections_cnt = 0;
-  int lines_cnt = 0;
-
-  for (struct opt_item * item = help->opt; item->cls != OPT_CL_END; item++) {
-    if (item->flags & OPT_NO_HELP) continue;
-    if (item->cls == OPT_CL_SECTION) {
-      sections_cnt++;
-      continue;
-    }
-    if (!*(item->help)) {
-      lines_cnt++;
-      continue;
-    }
-    FOREACHLINE(item->help)
-      lines_cnt++;
-  }
-
-  struct opt_sectlist {
-    int pos;
-    struct opt_section * sect;
-  } sections[sections_cnt];
-  int s = 0;
-
-  const char *lines[lines_cnt][3];
-  memset(lines, 0, sizeof(lines));
-  int line = 0;
-
-  int linelengths[3] = { -1, -1, -1 };
-
-  for (struct opt_item * item = help->opt; item->cls != OPT_CL_END; item++) {
-    if (item->flags & OPT_NO_HELP) continue;
-
-    if (item->cls == OPT_CL_HELP) {
-      if (!*(item->help)) {
-	line++;
-	continue;
-      }
-#define SPLITLINES(text) do { \
-      FOREACHLINE(text) { \
-	int cell = 0; \
-	for (const char * b = begin, * e = begin; (e < end) && (e = strchrnul(b, '\t')) && (e > end ? (e = end) : end); b = e+1) { \
-	  lines[line][cell] = b; \
-	  if (cell >= 2) \
-	    break; \
-	  else \
-	    if (*e == '\t' && linelengths[cell] < (e - b)) \
-	      linelengths[cell] = e-b; \
-	  cell++; \
-	} \
-	line++; \
-      } } while (0)
-      SPLITLINES(item->help);
-      continue;
-    }
-
-    if (item->cls == OPT_CL_SECTION) {
-      sections[s++] = (struct opt_sectlist) { .pos = line, .sect = item->u.section };
-      continue;
-    }
-
-    uns valoff = strchrnul(item->help, '\t') - item->help;
-    uns eol = strchrnul(item->help, '\n') - item->help;
-    if (valoff > eol)
-      valoff = eol;
-#define VAL(it) ((OPT_ITEM_FLAGS(it) & OPT_REQUIRED_VALUE) ? stk_printf("=%.*s", valoff, item->help)  : ((OPT_ITEM_FLAGS(it) & OPT_NO_VALUE) ? "" : stk_printf("(=%.*s)", valoff, item->help)))
-    if (item->name) {
-      lines[line][1] = stk_printf("--%s%s", item->name, VAL(item));
-      if (linelengths[1] < (int) strlen(lines[line][1]))
-	linelengths[1] = strlen(lines[line][1]);
-      lines[line][0] = "";
-      if (linelengths[0] < 0)
-	linelengths[0] = 0;
-    }
-    if (item->letter) {
-      lines[line][0] = stk_printf("-%c,", item->letter);
-      if (linelengths[0] < (int) strlen(lines[line][0]))
-	linelengths[0] = strlen(lines[line][0]);
-    }
-#undef VAL
+static char *opt_name(struct opt_context *oc, struct opt_precomputed *opt)
+{
+  struct opt_item *item = opt->item;
+  char *res;
+  if (item->letter >= OPT_POSITIONAL_TAIL)
+    res = stk_printf("positional argument #%d", oc->positional_count);
+  else if (opt->flags & OPT_SEEN_AS_LONG)
+    res = stk_printf("--%s", opt->name);
+  else
+    res = stk_printf("-%c", item->letter);
+  return xstrdup(res);
+}
 
-    if (eol > valoff) {
-      lines[line][2] = item->help + valoff + 1;
-    }
+#define THIS_OPT opt_name(oc, opt)
 
-    line++;
+void opt_precompute(struct opt_precomputed *opt, struct opt_item *item)
+{
+  opt->item = item;
+  opt->count = 0;
+  opt->name = item->name;
+  uns flags = item->flags;
 
-    if (*(item->help + eol))
-      SPLITLINES(item->help + eol + 1);
-  }
-#undef SPLITLINES
-
-  s = 0;
-#define FIELD(k) linelengths[k], MIN(strchrnul(lines[i][k], '\t')-lines[i][k],strchrnul(lines[i][k], '\n')-lines[i][k]), lines[i][k]
-#define LASTFIELD(k) MIN(strchrnul(lines[i][k], '\t')-lines[i][k],strchrnul(lines[i][k], '\n')-lines[i][k]), lines[i][k]
-  for (int i=0;i<line;i++) {
-    while (s < sections_cnt && sections[s].pos == i) {
-      opt_help_internal(sections[s].sect);
-      s++;
-    }
-    if (lines[i][0] == NULL)
-      printf("\n");
-    else if (linelengths[0] == -1 || lines[i][1] == NULL)
-      printf("%.*s\n", LASTFIELD(0));
-    else if (linelengths[1] == -1 || lines[i][2] == NULL)
-      printf("%-*.*s  %.*s\n", FIELD(0), LASTFIELD(1));
-    else
-      printf("%-*.*s  %-*.*s  %.*s\n", FIELD(0), FIELD(1), LASTFIELD(2));
+  if (item->letter >= OPT_POSITIONAL_TAIL) {
+    flags &= ~OPT_VALUE_FLAGS;
+    flags |= OPT_REQUIRED_VALUE;
   }
-  while (s < sections_cnt && sections[s].pos == line) {
-    opt_help_internal(sections[s].sect);
-    s++;
+  if (!(flags & OPT_VALUE_FLAGS)) {
+    ASSERT(item->cls != OPT_CL_CALL && item->cls != OPT_CL_USER);
+    flags |= opt_default_value_flags[item->cls];
   }
-}
 
-static int opt_positional_max = 0;
-static int opt_positional_count = 0;
-
-struct opt_precomputed {
-  struct opt_precomputed_option {
-    struct opt_precomputed *pre;
-    struct opt_item * item;
-    const char * name;
-    short flags;
-    short count;
-  } ** opts;
-  struct opt_precomputed_option ** shortopt;
-  struct opt_item ** hooks_before_arg;
-  struct opt_item ** hooks_before_value;
-  struct opt_item ** hooks_after_value;
-  short opt_count;
-  short hooks_before_arg_count;
-  short hooks_before_value_count;
-  short hooks_after_value_count;
-};
+  opt->flags = flags;
+}
 
-static struct opt_precomputed_option * opt_find_item_shortopt(int chr, struct opt_precomputed * pre) {
-  struct opt_precomputed_option * candidate = pre->shortopt[chr];
-  if (!candidate)
-    opt_failure("Invalid option -%c", chr);
-  if (candidate->count++ && (candidate->flags & OPT_SINGLE))
-    opt_failure("Option -%c appeared the second time.", candidate->item->letter);
-  return candidate;
+static void opt_invoke_hooks(struct opt_context *oc, uns event, struct opt_item *item, char *value)
+{
+  for (int i = 0; i < oc->hook_count; i++) {
+    struct opt_item *hook = oc->hooks[i];
+    if (hook->flags & event) {
+      void *data = (hook->flags & OPT_HOOK_INTERNAL) ? oc : hook->ptr;
+      hook->u.hook(item, event, value, data);
+    }
+  }
 }
 
-static struct opt_precomputed_option * opt_find_item_longopt(char * str, struct opt_precomputed * pre) {
+static struct opt_precomputed * opt_find_item_longopt(struct opt_context * oc, char * str) {
   uns len = strlen(str);
-  struct opt_precomputed_option * candidate = NULL;
+  struct opt_precomputed * candidate = NULL;
 
-  for (int i=0; i<pre->opt_count; i++) {
-    if (!pre->opts[i]->name)
+  for (int i = 0; i < oc->opt_count; i++) {
+    struct opt_precomputed *opt = &oc->opts[i];
+    if (!opt->name)
       continue;
-    if (!strncmp(pre->opts[i]->name, str, len)) {
-      if (strlen(pre->opts[i]->name) == len) {
-	if (pre->opts[i]->count++ && (pre->opts[i]->flags & OPT_SINGLE))
-	  opt_failure("Option %s appeared the second time.", pre->opts[i]->name);
 
-	return pre->opts[i];
-      }
-      if (candidate)
-	opt_failure("Ambiguous prefix %s: Found matching %s and %s.", str, candidate->name, pre->opts[i]->name);
-      else
-	candidate = pre->opts[i];
-    }
-    if (!strncmp("no-", str, 3) && !strncmp(pre->opts[i]->name, str+3, len-3)) {
-      if (strlen(pre->opts[i]->name) == len-3) {
-	if (pre->opts[i]->count++ && (pre->opts[i]->flags & OPT_SINGLE))
-	  opt_failure("Option %s appeared the second time.", pre->opts[i]->name);
+    if (!strncmp(opt->name, str, len)) {
+      if (strlen(opt->name) == len)
+	return opt;
+    } else if (opt->item->cls == OPT_CL_BOOL && !strncmp("no-", str, 3) && !strncmp(opt->name, str+3, len-3)) {
+      if (strlen(opt->name) == len-3)
+	return opt;
+    } else
+      continue;
 
-	return pre->opts[i];
-      }
-      if (candidate)
-	opt_failure("Ambiguous prefix %s: Found matching %s and %s.", str, candidate->name, pre->opts[i]->name);
-      else
-	candidate = pre->opts[i];
-    }
+    if (candidate)
+      opt_failure("Ambiguous option --%s: matches both --%s and --%s.", str, candidate->name, opt->name);
+    else
+      candidate = opt;
   }
 
   if (candidate)
     return candidate;
 
-  opt_failure("Invalid option %s.", str);
+  opt_failure("Invalid option --%s.", str);
 }
 
-#define OPT_PTR(type) ({ \
-  type * ptr; \
-  if (item->flags & OPT_MULTIPLE) { \
-    struct { \
-      cnode n; \
-      type v; \
-    } * n = xmalloc(sizeof(*n)); \
-    clist_add_tail(item->ptr, &(n->n)); \
-    ptr = &(n->v); \
-  } else \
-    ptr = item->ptr; \
+// FIXME: Use simple-lists?
+#define OPT_PTR(type) ({ 			\
+  type * ptr; 					\
+  if (item->flags & OPT_MULTIPLE) { 		\
+    struct { 					\
+      cnode n; 					\
+      type v; 					\
+    } * n = xmalloc(sizeof(*n)); 		\
+    clist_add_tail(item->ptr, &(n->n)); 	\
+    ptr = &(n->v); 				\
+  } else 					\
+    ptr = item->ptr; 				\
   ptr; })
 
-#define OPT_NAME (longopt == 2 ? stk_printf("positional arg #%d", opt_positional_count) : (longopt == 1 ? stk_printf("--%s", opt->name) : stk_printf("-%c", item->letter)))
-static void opt_parse_value(struct opt_precomputed_option * opt, char * value, int longopt) {
+static void opt_parse_value(struct opt_context * oc, struct opt_precomputed * opt, char * value) {
   struct opt_item * item = opt->item;
-  struct opt_precomputed * pre = opt->pre;
-  for (int i=0;i<pre->hooks_before_value_count;i++)
-    pre->hooks_before_value[i]->u.call(item, value, pre->hooks_before_value[i]->ptr);
+
+  if (opt->count++ && (opt->flags & OPT_SINGLE))
+    opt_failure("Option %s must be specified at most once.", THIS_OPT);
+
+  if (opt->flags & OPT_LAST_ARG)
+    oc->stop_parsing = 1;
+
+  opt_invoke_hooks(oc, OPT_HOOK_BEFORE_VALUE, item, value);
 
   switch (item->cls) {
     case OPT_CL_BOOL:
@@ -266,7 +143,7 @@ static void opt_parse_value(struct opt_precomputed_option * opt, char * value, i
       else if (!strcasecmp(value, "n") || !strcasecmp(value, "no") || !strcasecmp(value, "false") || !strcasecmp(value, "0"))
 	*((int *) item->ptr) = 0 ^ (!!(opt->flags & OPT_NEGATIVE));
       else
-	opt_failure("Boolean argument for %s has a strange value. Supported (case insensitive): y/n, yes/no, true/false.", OPT_NAME);
+	opt_failure("Boolean argument for %s has a strange value. Supported (case insensitive): 1/0, y/n, yes/no, true/false.", THIS_OPT);
       break;
     case OPT_CL_STATIC:
       {
@@ -278,7 +155,7 @@ static void opt_parse_value(struct opt_precomputed_option * opt, char * value, i
 	    else
 	      e = cf_parse_int(value, OPT_PTR(int));
 	    if (e)
-	      opt_failure("Integer value parsing failed for %s: %s", OPT_NAME, e);
+	      opt_failure("Integer value parsing failed for %s: %s", THIS_OPT, e);
 	    break;
 	  case CT_U64:
 	    if (!value)
@@ -286,7 +163,7 @@ static void opt_parse_value(struct opt_precomputed_option * opt, char * value, i
 	    else
 	      e = cf_parse_u64(value, OPT_PTR(u64));
 	    if (e)
-	      opt_failure("Unsigned 64-bit value parsing failed for %s: %s", OPT_NAME, e);
+	      opt_failure("Unsigned 64-bit value parsing failed for %s: %s", THIS_OPT, e);
 	    break;
 	  case CT_DOUBLE:
 	    if (!value)
@@ -294,15 +171,15 @@ static void opt_parse_value(struct opt_precomputed_option * opt, char * value, i
 	    else
 	      e = cf_parse_double(value, OPT_PTR(double));
 	    if (e)
-	      opt_failure("Double value parsing failed for %s: %s", OPT_NAME, e);
+	      opt_failure("Floating-point value parsing failed for %s: %s", THIS_OPT, e);
 	    break;
 	  case CT_IP:
 	    if (!value)
-	      e = cf_parse_ip("0.0.0.0", OPT_PTR(u32));
+	      *OPT_PTR(u32) = 0;
 	    else
 	      e = cf_parse_ip(value, OPT_PTR(u32));
 	    if (e)
-	      opt_failure("IP parsing failed for %s: %s", OPT_NAME, e);
+	      opt_failure("IP address parsing failed for %s: %s", THIS_OPT, e);
 	    break;
 	  case CT_STRING:
 	    if (!value)
@@ -316,8 +193,8 @@ static void opt_parse_value(struct opt_precomputed_option * opt, char * value, i
 	break;
       }
     case OPT_CL_SWITCH:
-      if (*((int *)item->ptr) != -1)
-	opt_failure("Multiple switches: %s", OPT_NAME);
+      if ((opt->flags & OPT_SINGLE) && *((int *)item->ptr) != -1)
+	opt_failure("Multiple switches: %s", THIS_OPT);
       else
 	*((int *)item->ptr) = item->u.value;
       break;
@@ -328,300 +205,199 @@ static void opt_parse_value(struct opt_precomputed_option * opt, char * value, i
 	(*((int *)item->ptr))++;
       break;
     case OPT_CL_CALL:
-      item->u.call(item, value, item->ptr);
-      break;
+      {
+	void *data = (opt->flags & OPT_INTERNAL) ? oc : item->ptr;
+	item->u.call(item, value, data);
+	break;
+      }
     case OPT_CL_USER:
       {
 	char * e = NULL;
 	e = item->u.utype->parser(value, OPT_PTR(void*));
 	if (e)
-	  opt_failure("User defined type value parsing failed for %s: %s", OPT_NAME, e);
+	  opt_failure("Cannot parse the value of %s: %s", THIS_OPT, e);
 	break;
       }
     default:
       ASSERT(0);
   }
-  opt_parsed_count++;
 
-  for (int i=0;i<pre->hooks_after_value_count;i++)
-    pre->hooks_after_value[i]->u.call(item, value, pre->hooks_after_value[i]->ptr);
+  opt_invoke_hooks(oc, OPT_HOOK_AFTER_VALUE, item, value);
 }
-#undef OPT_NAME
 
-static int opt_longopt(char ** argv, int index, struct opt_precomputed * pre) {
+static int opt_longopt(struct opt_context * oc, char ** argv, int index) {
   int eaten = 0;
   char * name_in = argv[index] + 2; // skipping the -- on the beginning
   uns pos = strchrnul(name_in, '=') - name_in;
-  struct opt_precomputed_option * opt = opt_find_item_longopt(strndupa(name_in, pos), pre);
+  struct opt_precomputed * opt = opt_find_item_longopt(oc, strndupa(name_in, pos));
   char * value = NULL;
 
-  if (opt->item->cls == OPT_CL_BOOL && !strncmp(name_in, "no-", 3) && !strncmp(name_in+3, opt->item->name, pos-3))
+  opt->flags |= OPT_SEEN_AS_LONG;
+
+  if (opt->item->cls == OPT_CL_BOOL && !strncmp(name_in, "no-", 3) && !strncmp(name_in+3, opt->item->name, pos-3)) {
+    if (name_in[pos])
+      opt_failure("Option --%s must not have any value.", name_in);
     value = "n";
-  else if (opt->flags & OPT_REQUIRED_VALUE) {
-    if (pos < strlen(name_in))
+  } else if (opt->flags & OPT_REQUIRED_VALUE) {
+    if (name_in[pos])
       value = name_in + pos + 1;
     else {
       value = argv[index+1];
       if (!value)
-	opt_failure("Argument --%s must have a value but nothing supplied.", opt->name);
+	opt_failure("Option %s must have a value, but nothing supplied.", THIS_OPT);
       eaten++;
     }
-  }
-  else if (opt->flags & OPT_MAYBE_VALUE) {
-    if (pos < strlen(name_in))
+  } else if (opt->flags & OPT_MAYBE_VALUE) {
+    if (name_in[pos])
       value = name_in + pos + 1;
+  } else {
+    if (name_in[pos])
+      opt_failure("Option %s must have no value.", THIS_OPT);
   }
-  else {
-    if (pos < strlen(name_in))
-      opt_failure("Argument --%s must not have any value.", opt->name);
-  }
-  opt_parse_value(opt, value, 1);
+  opt_parse_value(oc, opt, value);
   return eaten;
 }
 
-static int opt_shortopt(char ** argv, int index, struct opt_precomputed * pre) {
+static int opt_shortopt(struct opt_context * oc, char ** argv, int index) {
   int chr = 0;
-  struct opt_precomputed_option * opt;
-  while (argv[index][++chr] && (opt = opt_find_item_shortopt(argv[index][chr], pre))) {
-    if (opt->flags & OPT_NO_VALUE) {
-      opt_parse_value(opt, NULL, 0);
-    }
+  struct opt_precomputed * opt;
+  int o;
+
+  while (o = argv[index][++chr]) {
+    if (o < 0 || o >= 128)
+      opt_failure("Invalid character 0x%02x in option name. Only ASCII is allowed.", o & 0xff);
+    opt = oc->shortopt[o];
+
+    if (!opt)
+      opt_failure("Unknown option -%c.", o);
+
+    opt->flags &= ~OPT_SEEN_AS_LONG;
+
+    if (opt->flags & OPT_NO_VALUE)
+      opt_parse_value(oc, opt, NULL);
     else if (opt->flags & OPT_REQUIRED_VALUE) {
-      if (chr == 1 && argv[index][2]) {
-        opt_parse_value(opt, argv[index] + 2, 0);
+      if (argv[index][chr+1]) {
+        opt_parse_value(oc, opt, argv[index] + chr + 1);
 	return 0;
-      }
-      else if (argv[index][chr+1])
-	opt_failure("Option -%c must have a value but found inside a bunch of short opts.", opt->item->letter);
-      else if (!argv[index+1])
-	opt_failure("Option -%c must have a value but nothing supplied.", opt->item->letter);
+      } else if (!argv[index+1])
+	opt_failure("Option -%c must have a value, but nothing supplied.", o);
       else {
-	opt_parse_value(opt, argv[index+1], 0);
+	opt_parse_value(oc, opt, argv[index+1]);
 	return 1;
       }
-    }
-    else if (opt->flags & OPT_MAYBE_VALUE) {
-      if (chr == 1 && argv[index][2]) {
-        opt_parse_value(opt, argv[index] + 2, 0);
+    } else if (opt->flags & OPT_MAYBE_VALUE) {
+      if (argv[index][chr+1]) {
+        opt_parse_value(oc, opt, argv[index] + chr + 1);
 	return 0;
-      }
-      else
-	opt_parse_value(opt, NULL, 0);
-    }
-    else {
+      } else
+	opt_parse_value(oc, opt, NULL);
+    } else {
       ASSERT(0);
     }
   }
 
-  if (argv[index][chr])
-    opt_failure("Unknown option -%c.", argv[index][chr]);
-
   return 0;
 }
 
-static void opt_positional(char * value, struct opt_precomputed * pre) {
-  opt_positional_count++;
-  struct opt_precomputed_option * opt = opt_find_item_shortopt((opt_positional_count > opt_positional_max ? 256 : opt_positional_count + 256), pre);
-  if (!opt) {
-    ASSERT(opt_positional_count > opt_positional_max);
-    opt_failure("Too many positional args.");
+static void opt_positional(struct opt_context * oc, char * value) {
+  oc->positional_count++;
+  uns id = oc->positional_count > oc->positional_max ? OPT_POSITIONAL_TAIL : OPT_POSITIONAL(oc->positional_count);
+  struct opt_precomputed * opt = oc->shortopt[id];
+  if (!opt)
+    opt_failure("Too many positional arguments.");
+  else {
+    opt->flags &= OPT_SEEN_AS_LONG;
+    opt_parse_value(oc, opt, value);
   }
-
-  opt_parse_value(opt, value, 2);
 }
 
-#define OPT_TRAVERSE_SECTIONS \
-    while (item->cls == OPT_CL_SECTION) { \
-      if (stk->next) \
-	stk = stk->next; \
-      else { \
-	struct opt_stack * new_stk = alloca(sizeof(*new_stk)); \
-	new_stk->prev = stk; \
-	stk->next = new_stk; \
-	stk = new_stk; \
-      } \
-      stk->this = item; \
-      item = item->u.section->opt; \
-    } \
-    if (item->cls == OPT_CL_END) { \
-      if (!stk->prev) break; \
-      item = stk->this; \
-      stk = stk->prev; \
-      continue; \
+static void opt_count_items(struct opt_context *oc, const struct opt_section *sec)
+{
+  for (const struct opt_item *item = sec->opt; item->cls != OPT_CL_END; item++) {
+    if (item->cls == OPT_CL_SECTION)
+      opt_count_items(oc, item->u.section);
+    else if (item->cls == OPT_CL_HOOK)
+      oc->hook_count++;
+    else if (item->letter || item->name) {
+      oc->opt_count++;
+      if (item->letter > OPT_POSITIONAL_TAIL)
+	oc->positional_max++;
     }
-
-void opt_parse(const struct opt_section * options, char ** argv) {
-  opt_section_root = options;
-
-  struct opt_stack {
-    struct opt_item * this;
-    struct opt_stack * prev;
-    struct opt_stack * next;
-  } * stk = alloca(sizeof(*stk));
-  stk->this = NULL;
-  stk->prev = NULL;
-  stk->next = NULL;
-
-  struct opt_precomputed * pre = alloca(sizeof(*pre));
-  memset(pre, 0, sizeof (*pre));
-
-  int count = 0;
-  int hooks = 0;
-
-  for (struct opt_item * item = options->opt; ; item++) {
-    OPT_TRAVERSE_SECTIONS;
-    if (item->letter || item->name)
-      count++;
-    if (item->cls == OPT_CL_BOOL)
-      count++;
-    if (item->letter > 256)
-      opt_positional_max++;
-    if (item->cls == OPT_CL_HOOK)
-      hooks++;
   }
+}
 
-  pre->opts = alloca(sizeof(*pre->opts) * count);
-  pre->shortopt = alloca(sizeof(*pre->shortopt) * (opt_positional_max + 257));
-  memset(pre->shortopt, 0, sizeof(*pre->shortopt) * (opt_positional_max + 257));
-  pre->hooks_before_arg = alloca(sizeof (*pre->hooks_before_arg) * hooks);
-  pre->hooks_before_value = alloca(sizeof (*pre->hooks_before_value) * hooks);
-  pre->hooks_after_value = alloca(sizeof (*pre->hooks_after_value) * hooks);
-
-  pre->hooks_before_arg_count = 0;
-  pre->hooks_before_value_count = 0;
-  pre->hooks_after_value_count = 0;
-
-  pre->opt_count = 0;
-
-  for (struct opt_item * item = options->opt; ; item++) {
-    OPT_TRAVERSE_SECTIONS;
-    if (item->letter || item->name) {
-      struct opt_precomputed_option * opt = xmalloc(sizeof(*opt));
-      opt->pre = pre;
-      opt->item = item;
-      opt->flags = item->flags;
-      opt->count = 0;
-      opt->name = item->name;
-      pre->opts[pre->opt_count++] = opt;
+static void opt_prepare_items(struct opt_context *oc, const struct opt_section *sec)
+{
+  for (struct opt_item *item = sec->opt; item->cls != OPT_CL_END; item++) {
+    if (item->cls == OPT_CL_SECTION)
+      opt_prepare_items(oc, item->u.section);
+    else if (item->cls == OPT_CL_HOOK)
+      oc->hooks[oc->hook_count++] = item;
+    else if (item->letter || item->name) {
+      struct opt_precomputed * opt = &oc->opts[oc->opt_count++];
+      opt_precompute(opt, item);
       if (item->letter)
-	pre->shortopt[(int) item->letter] = opt;
-      OPT_ADD_DEFAULT_ITEM_FLAGS(item, opt->flags);
+	oc->shortopt[(int) item->letter] = opt;
     }
-    if (item->cls == OPT_CL_HOOK) {
-      if (item->flags & OPT_HOOK_BEFORE_ARG)
-	pre->hooks_before_arg[pre->hooks_before_arg_count++] = item;
-      else if (item->flags & OPT_HOOK_BEFORE_VALUE)
-	pre->hooks_before_value[pre->hooks_before_value_count++] = item;
-      else if (item->flags & OPT_HOOK_AFTER_VALUE)
-	pre->hooks_after_value[pre->hooks_after_value_count++] = item;
+  }
+}
+
+static void opt_check_required(struct opt_context *oc)
+{
+  for (int i = 0; i < oc->opt_count; i++) {
+    struct opt_precomputed *opt = &oc->opts[i];
+    if (!opt->count && (opt->flags & OPT_REQUIRED)) {
+      struct opt_item *item = opt->item;
+      if (item->letter > OPT_POSITIONAL_TAIL)
+	opt_failure("Required positional argument #%d not found.", item->letter - OPT_POSITIONAL_TAIL);
+      else if (item->letter == OPT_POSITIONAL_TAIL)
+	opt_failure("Required positional argument not found.");
+      else if (item->letter && item->name)
+	opt_failure("Required option -%c/--%s not found.", item->letter, item->name);
+      else if (item->letter)
+	opt_failure("Required option -%c not found.", item->letter);
       else
-	ASSERT(0);
+	opt_failure("Required option --%s not found.", item->name);
     }
   }
+}
+
+int opt_parse(const struct opt_section * options, char ** argv) {
+  struct opt_context * oc = alloca(sizeof(*oc));
+  memset(oc, 0, sizeof (*oc));
+  oc->options = options;
+
+  opt_count_items(oc, options);
+  oc->opts = alloca(sizeof(*oc->opts) * oc->opt_count);
+  oc->shortopt = alloca(sizeof(*oc->shortopt) * (oc->positional_max + 257));
+  memset(oc->shortopt, 0, sizeof(*oc->shortopt) * (oc->positional_max + 257));
+  oc->hooks = alloca(sizeof (*oc->hooks) * oc->hook_count);
+
+  oc->opt_count = 0;
+  oc->hook_count = 0;
+  opt_prepare_items(oc, options);
 
   int force_positional = 0;
-  for (int i=0;argv[i];i++) {
-    for (int j=0;j<pre->hooks_before_arg_count;j++)
-      pre->hooks_before_arg[j]->u.call(NULL, NULL, pre->hooks_before_arg[j]->ptr);
-    if (argv[i][0] != '-' || force_positional) {
-      opt_positional(argv[i], pre);
-    }
+  int i;
+  for (i=0; argv[i] && !oc->stop_parsing; i++) {
+    char *arg = argv[i];
+    opt_invoke_hooks(oc, OPT_HOOK_BEFORE_ARG, NULL, NULL);
+    if (arg[0] != '-' || force_positional)
+      opt_positional(oc, arg);
     else {
-      if (argv[i][1] == '-') {
-	if (argv[i][2] == '\0')
+      if (arg[1] == '-') {
+	if (arg[2] == '\0')
 	  force_positional++;
 	else
-	  i += opt_longopt(argv, i, pre);
-      }
-      else if (argv[i][1])
-	i += opt_shortopt(argv, i, pre);
+	  i += opt_longopt(oc, argv, i);
+      } else if (arg[1])
+	i += opt_shortopt(oc, argv, i);
       else
-	opt_positional(argv[i], pre);
+	opt_positional(oc, arg);
     }
   }
 
-  for (int i=0;i<opt_positional_max+257;i++) {
-    if (!pre->shortopt[i])
-      continue;
-    if (!pre->shortopt[i]->count && (pre->shortopt[i]->flags & OPT_REQUIRED))
-      if (i < 256)
-        opt_failure("Required option -%c not found.\n", pre->shortopt[i]->item->letter);
-      else
-	opt_failure("Required positional argument #%d not found.\n", (i > 256) ? pre->shortopt[i]->item->letter-256 : opt_positional_max+1);
-  }
-
-  for (int i=0;i<pre->opt_count;i++) {
-    if (!pre->opts[i])
-      continue;
-    if (!pre->opts[i]->count && (pre->opts[i]->flags & OPT_REQUIRED))
-      opt_failure("Required option --%s not found.\n", pre->opts[i]->item->name);
-  }
-}
-
-static void opt_conf_end_of_options(struct cf_context *cc) {
-  cf_load_default(cc);
-  if (cc->postpone_commit && cf_close_group())
-    opt_failure("Loading of configuration failed");
-}
-
-void opt_conf_internal(struct opt_item * opt, const char * value, void * data UNUSED) {
-  struct cf_context *cc = cf_get_context();
-  switch (opt->letter) {
-    case 'S':
-      cf_load_default(cc);
-      if (cf_set(value))
-	opt_failure("Cannot set %s", value);
-      break;
-    case 'C':
-      if (cf_load(value))
-	opt_failure("Cannot load config file %s", value);
-      break;
-#ifdef CONFIG_UCW_DEBUG
-    case '0':
-      opt_conf_end_of_options(cc);
-      struct fastbuf *b = bfdopen(1, 4096);
-      cf_dump_sections(b);
-      bclose(b);
-      exit(0);
-      break;
-#endif
-  }
-
-  opt_conf_parsed_count++;
-}
-
-void opt_conf_hook_internal(struct opt_item * opt, const char * value UNUSED, void * data UNUSED) {
-  static enum {
-    OPT_CONF_HOOK_BEGIN,
-    OPT_CONF_HOOK_CONFIG,
-    OPT_CONF_HOOK_OTHERS
-  } state = OPT_CONF_HOOK_BEGIN;
-
-  int confopt = 0;
-
-  if (opt->letter == 'S' || opt->letter == 'C' || (opt->name && !strcmp(opt->name, "dumpconfig")))
-    confopt = 1;
-
-  switch (state) {
-    case OPT_CONF_HOOK_BEGIN:
-      if (confopt)
-	state = OPT_CONF_HOOK_CONFIG;
-      else {
-	opt_conf_end_of_options(cf_get_context());
-	state = OPT_CONF_HOOK_OTHERS;
-      }
-      break;
-    case OPT_CONF_HOOK_CONFIG:
-      if (!confopt) {
-	opt_conf_end_of_options(cf_get_context());
-	state = OPT_CONF_HOOK_OTHERS;
-      }
-      break;
-    case OPT_CONF_HOOK_OTHERS:
-      if (confopt)
-	opt_failure("Config options (-C, -S) must stand before other options.");
-      break;
-    default:
-      ASSERT(0);
-  }
+  opt_check_required(oc);
+  opt_invoke_hooks(oc, OPT_HOOK_FINAL, NULL, NULL);
+  return i;
 }