src/basic/alloc-util.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #pragma once
   4
   5 /***
   6   This file is part of systemd.
   7
   8   Copyright 2010 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 ***/
  23
  24 #include <alloca.h>
  25 #include <stddef.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28
  29 #include "macro.h"
  30
  31 #define new(t, n) ((t*) malloc_multiply(sizeof(t), (n)))
  32
  33 #define new0(t, n) ((t*) calloc((n), sizeof(t)))
  34
  35 #define newa(t, n) ((t*) alloca(sizeof(t)*(n)))
  36
  37 #define newa0(t, n) ((t*) alloca0(sizeof(t)*(n)))
  38
  39 #define newdup(t, p, n) ((t*) memdup_multiply(p, sizeof(t), (n)))
  40
  41 #define malloc0(n) (calloc(1, (n)))
  42
  43 static inline void *mfree(void *memory) {
  44         free(memory);
  45         return NULL;
  46 }
  47
  48 void* memdup(const void *p, size_t l) _alloc_(2);
  49
  50 static inline void freep(void *p) {
  51         free(*(void**) p);
  52 }
  53
  54 #define _cleanup_free_ _cleanup_(freep)
  55
  56 _malloc_  _alloc_(1, 2) static inline void *malloc_multiply(size_t a, size_t b) {
  57         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
  58                 return NULL;
  59
  60         return malloc(a * b);
  61 }
  62
  63 _alloc_(2, 3) static inline void *realloc_multiply(void *p, size_t a, size_t b) {
  64         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
  65                 return NULL;
  66
  67         return realloc(p, a * b);
  68 }
  69
  70 _alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t a, size_t b) {
  71         if (_unlikely_(b != 0 && a > ((size_t) -1) / b))
  72                 return NULL;
  73
  74         return memdup(p, a * b);
  75 }
  76
  77 void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
  78 void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
  79
  80 #define GREEDY_REALLOC(array, allocated, need)                          \
  81         greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
  82
  83 #define GREEDY_REALLOC0(array, allocated, need)                         \
  84         greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
  85
  86 #define alloca0(n)                                      \
  87         ({                                              \
  88                 char *_new_;                            \
  89                 size_t _len_ = n;                       \
  90                 _new_ = alloca(_len_);                  \
  91                 (void *) memset(_new_, 0, _len_);       \
  92         })
  93
  94 /* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
  95 #define alloca_align(size, align)                                       \
  96         ({                                                              \
  97                 void *_ptr_;                                            \
  98                 size_t _mask_ = (align) - 1;                            \
  99                 _ptr_ = alloca((size) + _mask_);                        \
 100                 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_);         \
 101         })
 102
 103 #define alloca0_align(size, align)                                      \
 104         ({                                                              \
 105                 void *_new_;                                            \
 106                 size_t _size_ = (size);                                 \
 107                 _new_ = alloca_align(_size_, (align));                  \
 108                 (void*)memset(_new_, 0, _size_);                        \
 109         })