1 # calloc.m4 serial 15 2 3 # Copyright (C) 2004-2012 Free Software Foundation, Inc. 4 # This file is free software; the Free Software Foundation 5 # gives unlimited permission to copy and/or distribute it, 6 # with or without modifications, as long as this notice is preserved. 7 8 # Written by Jim Meyering. 9 10 # Determine whether calloc (N, S) returns non-NULL when N*S is zero, 11 # and returns NULL when N*S overflows. 12 # If so, define HAVE_CALLOC. Otherwise, define calloc to rpl_calloc 13 # and arrange to use a calloc wrapper function that does work in that case. 14 15 # _AC_FUNC_CALLOC_IF([IF-WORKS], [IF-NOT]) 16 # ------------------------------------- 17 # If 'calloc (0, 0)' is properly handled, run IF-WORKS, otherwise, IF-NOT. 18 AC_DEFUN([_AC_FUNC_CALLOC_IF], 19 [ 20 AC_REQUIRE([AC_TYPE_SIZE_T])dnl 21 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 22 AC_CACHE_CHECK([for GNU libc compatible calloc], 23 [ac_cv_func_calloc_0_nonnull], 24 [AC_RUN_IFELSE( 25 [AC_LANG_PROGRAM( 26 [AC_INCLUDES_DEFAULT], 27 [[int result = 0; 28 if (!calloc (0, 0)) 29 result |= 1; 30 if (calloc ((size_t) -1 / 8 + 1, 8)) 31 result |= 2; 32 return result; 33 ]])], 34 [ac_cv_func_calloc_0_nonnull=yes], 35 [ac_cv_func_calloc_0_nonnull=no], 36 [case "$host_os" in 37 # Guess yes on glibc systems. 38 *-gnu*) ac_cv_func_calloc_0_nonnull="guessing yes" ;; 39 # If we don't know, assume the worst. 40 *) ac_cv_func_calloc_0_nonnull="guessing no" ;; 41 esac 42 ])]) 43 case "$ac_cv_func_calloc_0_nonnull" in 44 *yes) 45 $1 46 ;; 47 *) 48 $2 49 ;; 50 esac 51 ])# AC_FUNC_CALLOC 52 53 54 # gl_FUNC_CALLOC_GNU 55 # ------------------ 56 # Report whether 'calloc (0, 0)' is properly handled, and replace calloc if 57 # needed. 58 AC_DEFUN([gl_FUNC_CALLOC_GNU], 59 [ 60 AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) 61 _AC_FUNC_CALLOC_IF( 62 [AC_DEFINE([HAVE_CALLOC_GNU], [1], 63 [Define to 1 if your system has a GNU libc compatible 'calloc' 64 function, and to 0 otherwise.])], 65 [AC_DEFINE([HAVE_CALLOC_GNU], [0]) 66 REPLACE_CALLOC=1 67 ]) 68 ])# gl_FUNC_CALLOC_GNU 69 70 71 # gl_FUNC_CALLOC_POSIX 72 # -------------------- 73 # Test whether 'calloc' is POSIX compliant (sets errno to ENOMEM when it 74 # fails), and replace calloc if it is not. 75 AC_DEFUN([gl_FUNC_CALLOC_POSIX], 76 [ 77 AC_REQUIRE([gl_STDLIB_H_DEFAULTS]) 78 AC_REQUIRE([gl_CHECK_MALLOC_POSIX]) 79 if test $gl_cv_func_malloc_posix = yes; then 80 AC_DEFINE([HAVE_CALLOC_POSIX], [1], 81 [Define if the 'calloc' function is POSIX compliant.]) 82 else 83 REPLACE_CALLOC=1 84 fi 85 ]) 86
