/* Declarations for wget-macros.h
   Copyright (C) 1996-2007 Free Software Foundation, Inc.

This file is part of GNU Wget.

GNU Wget 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.

GNU Wget 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 Wget.  If not, see <http://www.gnu.org/licenses/>.

In addition, as a special exception, the Free Software Foundation
gives permission to link the code of its release of Wget with the
OpenSSL project's "OpenSSL" library (or with modified versions of it
that use the same license as the "OpenSSL" library), and distribute
the linked executables.  You must obey the GNU General Public License
in all respects for all of the code used other than "OpenSSL".  If you
modify this file, you may extend this exception to your version of the
file, but you are not obligated to do so.  If you do not wish to do
so, delete this exception statement from your version.  */

/* This file contains some useful macros that are shared between the
   independent html-parser (html-parse.c) and the rest of wget. */

#ifndef WGET_MACROS_H
#define WGET_MACROS_H

/* The number of elements in an array.  For example:
   static char a[] = "foo";     -- countof(a) == 4 (note terminating \0)
   int a[5] = {1, 2};           -- countof(a) == 5
   char *a[] = {                -- countof(a) == 3
     "foo", "bar", "baz"
   }; */
#define countof(array) (sizeof (array) / sizeof ((array)[0]))

/* Convert an ASCII hex digit to the corresponding number between 0
   and 15.  H should be a hexadecimal digit that satisfies isxdigit;
   otherwise, the result is undefined.  */
#define XDIGIT_TO_NUM(h) ((h) < 'A' ? (h) - '0' : TOUPPER (h) - 'A' + 10)
#define X2DIGITS_TO_NUM(h1, h2) ((XDIGIT_TO_NUM (h1) << 4) + XDIGIT_TO_NUM (h2))

/* The reverse of the above: convert a number in the [0, 16) range to
   the ASCII representation of the corresponding hexadecimal digit.
   `+ 0' is there so you can't accidentally use it as an lvalue.  */
#define XNUM_TO_DIGIT(x) ("0123456789ABCDEF"[x] + 0)
#define XNUM_TO_digit(x) ("0123456789abcdef"[x] + 0)

/* Copy the data delimited with BEG and END to alloca-allocated
   storage, and zero-terminate it.  Arguments are evaluated only once,
   in the order BEG, END, PLACE.  */
#define BOUNDED_TO_ALLOCA(beg, end, place) do {	\
  const char *BTA_beg = (beg);			\
  int BTA_len = (end) - BTA_beg;		\
  char **BTA_dest = &(place);			\
  *BTA_dest = alloca (BTA_len + 1);		\
  memcpy (*BTA_dest, BTA_beg, BTA_len);		\
  (*BTA_dest)[BTA_len] = '\0';			\
} while (0)

/* Return non-zero if string bounded between BEG and END is equal to
   STRING_LITERAL.  The comparison is case-sensitive.  */
#define BOUNDED_EQUAL(beg, end, string_literal)				\
  ((end) - (beg) == sizeof (string_literal) - 1				\
   && !memcmp (beg, string_literal, sizeof (string_literal) - 1))

/* The same as above, except the comparison is case-insensitive. */
#define BOUNDED_EQUAL_NO_CASE(beg, end, string_literal)			\
  ((end) - (beg) == sizeof (string_literal) - 1				\
   && !strncasecmp (beg, string_literal, sizeof (string_literal) - 1))

/* Zero out a value.  */
#define xzero(x) memset (&(x), '\0', sizeof (x))

/* Like ptr=strdup(str), but allocates the space for PTR on the stack.
   This cannot be an expression because this is not portable:
     #define STRDUP_ALLOCA(str) (strcpy (alloca (strlen (str) + 1), str))
   The problem is that some compilers can't handle alloca() being an
   argument to a function.  */

#define STRDUP_ALLOCA(ptr, str) do {			\
  char **SA_dest = &(ptr);				\
  const char *SA_src = (str);				\
  *SA_dest = (char *)alloca (strlen (SA_src) + 1);	\
  strcpy (*SA_dest, SA_src);				\
} while (0)

/* Generally useful if you want to avoid arbitrary size limits but
   don't need a full dynamic array.  Assumes that BASEVAR points to a
   malloced array of TYPE objects (or possibly a NULL pointer, if
   SIZEVAR is 0), with the total size stored in SIZEVAR.  This macro
   will realloc BASEVAR as necessary so that it can hold at least
   NEEDED_SIZE objects.  The reallocing is done by doubling, which
   ensures constant amortized time per element.  */

#define DO_REALLOC(basevar, sizevar, needed_size, type)	do {		\
  long DR_needed_size = (needed_size);					\
  long DR_newsize = 0;							\
  while ((sizevar) < (DR_needed_size)) {				\
    DR_newsize = sizevar << 1;						\
    if (DR_newsize < 16)						\
      DR_newsize = 16;							\
    (sizevar) = DR_newsize;						\
  }									\
  if (DR_newsize)							\
    basevar = xrealloc (basevar, DR_newsize * sizeof (type));		\
} while (0)

/* Used to print pointers (usually for debugging).  Print pointers
   using printf ("0x%0*lx", PTR_FORMAT (p)).  (%p is too unpredictable;
   some implementations prepend 0x, while some don't, and most don't
   0-pad the address.)  */
#define PTR_FORMAT(p) (int) (2 * sizeof (void *)), (unsigned long) (p)

#endif /* WGET_MACROS_H */