/* ------------------------------------------------------------ */
/*
HTTrack Website Copier, Offline Browser for Windows and Unix
Copyright (C) 1998-2014 Xavier Roche and other contributors

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/>.

Important notes:

- We hereby ask people using this source NOT to use it in purpose of grabbing
emails addresses, or collecting any other private information on persons.
This would disgrace our work, and spoil the many hours we spent on it.

Please visit our Website: http://www.httrack.com
*/

/* ------------------------------------------------------------ */
/* File: htssafe.h safe strings operations, and asserts         */
/* Author: Xavier Roche                                         */
/* ------------------------------------------------------------ */

#ifndef HTSSAFE_DEFH
#define HTSSAFE_DEFH

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "htsglobal.h"

/**
 * Emergency logging.
 * Default is to use libhttrack one.
 */
#if (!defined(HTSSAFE_ABORT_FUNCTION) && defined(LIBHTTRACK_EXPORTS))

/** Assert error callback. **/
#ifndef HTS_DEF_FWSTRUCT_htsErrorCallback
#define HTS_DEF_FWSTRUCT_htsErrorCallback
typedef void (*htsErrorCallback) (const char *msg, const char *file, int line);
#ifdef __cplusplus
extern "C" {
#endif
HTSEXT_API htsErrorCallback hts_get_error_callback(void);
#ifdef __cplusplus
}
#endif
#endif

#define HTSSAFE_ABORT_FUNCTION(A,B,C) do { \
  htsErrorCallback callback = hts_get_error_callback(); \
  if (callback != NULL) { \
    callback(A,B,C); \
  } \
} while(0)

#endif

/**
 * Log an abort condition, and calls abort().
 */
#define abortLog(a) abortf_(a, __FILE__, __LINE__)

/**
 * Fatal assertion check.
 */
#define assertf__(exp, sexp, file, line) (void) ( (exp) || (abortf_(sexp, file, line), 0) )

/**
 * Fatal assertion check.
 */
#define assertf_(exp, file, line) assertf__(exp, #exp, file, line)

/**
 * Fatal assertion check.
 */
#define assertf(exp) assertf_(exp, __FILE__, __LINE__)

static HTS_UNUSED void log_abort_(const char *msg, const char *file, int line) {
  fprintf(stderr, "%s failed at %s:%d\n", msg, file, line);
  fflush(stderr);
}

static HTS_UNUSED void abortf_(const char *exp, const char *file, int line) {
#ifdef HTSSAFE_ABORT_FUNCTION
  HTSSAFE_ABORT_FUNCTION(exp, file, line);
#endif
  log_abort_(exp, file, line);
  abort();
}

/**
 * Check wether 'VAR' is of type char[].
 */
#if (defined(__GNUC__) && !defined(__cplusplus))
/* Note: char[] and const char[] are compatible */
#define HTS_IS_CHAR_BUFFER(VAR) ( __builtin_types_compatible_p ( typeof (VAR), char[] ) )
#else
/* Note: a bit lame as char[8] won't be seen. */
#define HTS_IS_CHAR_BUFFER(VAR) ( sizeof(VAR) != sizeof(char*) )
#endif
#define HTS_IS_NOT_CHAR_BUFFER(VAR) ( ! HTS_IS_CHAR_BUFFER(VAR) )

/* Compile-time checks. */
static HTS_UNUSED void htssafe_compile_time_check_(void) {
  char array[32];
  char *pointer = array;
  char check_array[HTS_IS_CHAR_BUFFER(array) ? 1 : -1];
  char check_pointer[HTS_IS_CHAR_BUFFER(pointer) ? -1 : 1];
  (void) pointer;
  (void) check_array;
  (void) check_pointer;
}

/**
 * Append at most N characters from "B" to "A".
 * If "A" is a char[] variable whose size is not sizeof(char*), then the size 
 * is assumed to be the capacity of this array.
 */
#define strncatbuff(A, B, N) \
  ( HTS_IS_NOT_CHAR_BUFFER(A) \
  ? ( (N) != (size_t) -1 ? strncat(A, B, N) : strcat(A, B) ) \
  : strncat_safe_(A, sizeof(A), B, \
  HTS_IS_NOT_CHAR_BUFFER(B) ? (size_t) -1 : sizeof(B), N, \
  "overflow while appending '" #B "' to '"#A"'", __FILE__, __LINE__) )

/**
 * Append characters of "B" to "A".
 * If "A" is a char[] variable whose size is not sizeof(char*), then the size 
 * is assumed to be the capacity of this array.
 */
#define strcatbuff(A, B) \
  ( HTS_IS_NOT_CHAR_BUFFER(A) \
  ? strcat(A, B) \
  : strncat_safe_(A, sizeof(A), B, \
  HTS_IS_NOT_CHAR_BUFFER(B) ? (size_t) -1 : sizeof(B), (size_t) -1, \
  "overflow while appending '" #B "' to '"#A"'", __FILE__, __LINE__) )

/**
 * Copy characters from "B" to "A".
 * If "A" is a char[] variable whose size is not sizeof(char*), then the size 
 * is assumed to be the capacity of this array.
 */
#define strcpybuff(A, B) \
  ( HTS_IS_NOT_CHAR_BUFFER(A) \
  ? strcpy(A, B) \
  : strcpy_safe_(A, sizeof(A), B, \
  HTS_IS_NOT_CHAR_BUFFER(B) ? (size_t) -1 : sizeof(B), \
  "overflow while copying '" #B "' to '"#A"'", __FILE__, __LINE__) )

/**
 * Append characters of "B" to "A", "A" having a maximum capacity of "S".
 */
#define strlcatbuff(A, B, S) \
  strncat_safe_(A, S, B, \
  HTS_IS_NOT_CHAR_BUFFER(B) ? (size_t) -1 : sizeof(B), (size_t) -1, \
  "overflow while appending '" #B "' to '"#A"'", __FILE__, __LINE__)

/**
 * Copy characters of "B" to "A", "A" having a maximum capacity of "S".
 */
#define strlcpybuff(A, B, S) \
  strcpy_safe_(A, S, B, \
  HTS_IS_NOT_CHAR_BUFFER(B) ? (size_t) -1 : sizeof(B), \
  "overflow while copying '" #B "' to '"#A"'", __FILE__, __LINE__)

static HTS_INLINE HTS_UNUSED size_t strlen_safe_(const char *source, const size_t sizeof_source, 
                                                 const char *file, int line) {
  size_t size;
  assertf_( source != NULL, file, line );
  size = sizeof_source != (size_t) -1 
    ? strnlen(source, sizeof_source) : strlen(source);
  assertf_( size < sizeof_source, file, line );
  return size;
}

static HTS_INLINE HTS_UNUSED char* strncat_safe_(char *const dest, const size_t sizeof_dest,
                                                 const char *const source, const size_t sizeof_source, 
                                                 const size_t n,
                                                 const char *exp, const char *file, int line) {
  const size_t source_len = strlen_safe_(source, sizeof_source, file, line);
  const size_t dest_len = strlen_safe_(dest, sizeof_dest, file, line);
  /* note: "size_t is an unsigned integral type" ((size_t) -1 is positive) */
  const size_t source_copy = source_len <= n ? source_len : n;
  const size_t dest_final_len = dest_len + source_copy;
  assertf__(dest_final_len < sizeof_dest, exp, file, line);
  memcpy(dest + dest_len, source, source_copy);
  dest[dest_final_len] = '\0';
  return dest;
}

static HTS_INLINE HTS_UNUSED char* strcpy_safe_(char *const dest, const size_t sizeof_dest,
                                                const char *const source, const size_t sizeof_source, 
                                                const char *exp, const char *file, int line) {
  assertf_(sizeof_dest != 0, file, line);
  dest[0] = '\0';
  return strncat_safe_(dest, sizeof_dest, source, sizeof_source, (size_t) -1, exp, file, line);
}

#define malloct(A)          malloc(A)
#define calloct(A,B)        calloc((A), (B))
#define freet(A)            do { if ((A) != NULL) { free(A); (A) = NULL; } } while(0)
#define strdupt(A)          strdup(A)
#define realloct(A,B)       realloc(A, B)
#define memcpybuff(A, B, N) memcpy((A), (B), (N))

#endif
