/*  alloc - Convenience routines for safely allocating memory
    Copyright (C) 2007-2009  Josh Coalson
    Copyright (C) 2011-2016  Xiph.Org Foundation

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    - Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    - Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    - Neither the name of the Xiph.org Foundation nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef FLAC__SHARE__ALLOC_H
#define FLAC__SHARE__ALLOC_H

//#ifdef HAVE_CONFIG_H
#  include "../config.h"
//#endif

/*  WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
    before #including this file,  otherwise SIZE_MAX might not be defined
*/

#include <limits.h> /* for SIZE_MAX */
//#if HAVE_STDINT_H
#include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
//#endif
#include <stdlib.h> /* for size_t, malloc(), etc */
#include "compat.h"

#ifndef SIZE_MAX
# ifndef SIZE_T_MAX
#  ifdef _MSC_VER
#   ifdef _WIN64
#    define SIZE_T_MAX FLAC__U64L(0xffffffffffffffff)
#   else
#    define SIZE_T_MAX 0xffffffff
#   endif
#  else
#   error
#  endif
# endif
# define SIZE_MAX SIZE_T_MAX
#endif

/*  avoid malloc()ing 0 bytes, see:
    https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
*/
static inline void *safe_malloc_(size_t size) {
    /* malloc(0) is undefined; FLAC src convention is to always allocate */
    if (!size) {
        size++;
    }
    return malloc(size);
}

static inline void *safe_calloc_(size_t nmemb, size_t size) {
    if (!nmemb || !size) {
        return malloc(1);    /* malloc(0) is undefined; FLAC src convention is to always allocate */
    }
    return calloc(nmemb, size);
}

/*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */

static inline void *safe_malloc_add_2op_(size_t size1, size_t size2) {
    size2 += size1;
    if (size2 < size1) {
        return 0;
    }
    return safe_malloc_(size2);
}

static inline void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3) {
    size2 += size1;
    if (size2 < size1) {
        return 0;
    }
    size3 += size2;
    if (size3 < size2) {
        return 0;
    }
    return safe_malloc_(size3);
}

static inline void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4) {
    size2 += size1;
    if (size2 < size1) {
        return 0;
    }
    size3 += size2;
    if (size3 < size2) {
        return 0;
    }
    size4 += size3;
    if (size4 < size3) {
        return 0;
    }
    return safe_malloc_(size4);
}

void *safe_malloc_mul_2op_(size_t size1, size_t size2) ;

static inline void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3) {
    if (!size1 || !size2 || !size3) {
        return malloc(1);    /* malloc(0) is undefined; FLAC src convention is to always allocate */
    }
    if (size1 > SIZE_MAX / size2) {
        return 0;
    }
    size1 *= size2;
    if (size1 > SIZE_MAX / size3) {
        return 0;
    }
    return malloc(size1 * size3);
}

/* size1*size2 + size3 */
static inline void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3) {
    if (!size1 || !size2) {
        return safe_malloc_(size3);
    }
    if (size1 > SIZE_MAX / size2) {
        return 0;
    }
    return safe_malloc_add_2op_(size1 * size2, size3);
}

/* size1 * (size2 + size3) */
static inline void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3) {
    if (!size1 || (!size2 && !size3)) {
        return malloc(1);    /* malloc(0) is undefined; FLAC src convention is to always allocate */
    }
    size2 += size3;
    if (size2 < size3) {
        return 0;
    }
    if (size1 > SIZE_MAX / size2) {
        return 0;
    }
    return malloc(size1 * size2);
}

static inline void *safe_realloc_(void *ptr, size_t size) {
    void *oldptr = ptr;
    void *newptr = realloc(ptr, size);
    if (size > 0 && newptr == 0) {
        free(oldptr);
    }
    return newptr;
}
static inline void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2) {
    size2 += size1;
    if (size2 < size1) {
        free(ptr);
        return 0;
    }
    return realloc(ptr, size2);
}

static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3) {
    size2 += size1;
    if (size2 < size1) {
        return 0;
    }
    size3 += size2;
    if (size3 < size2) {
        return 0;
    }
    return realloc(ptr, size3);
}

static inline void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4) {
    size2 += size1;
    if (size2 < size1) {
        return 0;
    }
    size3 += size2;
    if (size3 < size2) {
        return 0;
    }
    size4 += size3;
    if (size4 < size3) {
        return 0;
    }
    return realloc(ptr, size4);
}

static inline void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2) {
    if (!size1 || !size2) {
        return realloc(ptr, 0);    /* preserve POSIX realloc(ptr, 0) semantics */
    }
    if (size1 > SIZE_MAX / size2) {
        return 0;
    }
    return safe_realloc_(ptr, size1 * size2);
}

/* size1 * (size2 + size3) */
static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3) {
    if (!size1 || (!size2 && !size3)) {
        return realloc(ptr, 0);    /* preserve POSIX realloc(ptr, 0) semantics */
    }
    size2 += size3;
    if (size2 < size3) {
        return 0;
    }
    return safe_realloc_mul_2op_(ptr, size1, size2);
}

#endif
