3 # Copyright (C) 2004-2020 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.
8 # Written by Jim Meyering.
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.
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],
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 [if test $cross_compiling != yes; then
25 ac_cv_func_calloc_0_nonnull=yes
28 [AC_INCLUDES_DEFAULT],
30 char * volatile p = calloc (0, 0);
37 [ac_cv_func_calloc_0_nonnull=no])
40 [AC_INCLUDES_DEFAULT],
42 char * volatile p = calloc ((size_t) -1 / 8 + 1, 8);
48 dnl The exit code of this program is 0 if calloc() succeeded (which
49 dnl it shouldn't), 2 if calloc() failed, or 1 if some leak sanitizer
50 dnl terminated the program as a result of the calloc() call.
51 [ac_cv_func_calloc_0_nonnull=no],
55 # Guess yes on glibc systems.
56 *-gnu* | gnu*) ac_cv_func_calloc_0_nonnull="guessing yes" ;;
57 # Guess yes on musl systems.
58 *-musl*) ac_cv_func_calloc_0_nonnull="guessing yes" ;;
59 # Guess yes on native Windows.
60 mingw*) ac_cv_func_calloc_0_nonnull="guessing yes" ;;
61 # If we don't know, obey --enable-cross-guesses.
62 *) ac_cv_func_calloc_0_nonnull="$gl_cross_guess_normal" ;;
66 case "$ac_cv_func_calloc_0_nonnull" in
79 # Report whether 'calloc (0, 0)' is properly handled, and replace calloc if
81 AC_DEFUN([gl_FUNC_CALLOC_GNU],
83 AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
85 [AC_DEFINE([HAVE_CALLOC_GNU], [1],
86 [Define to 1 if your system has a GNU libc compatible 'calloc'
87 function, and to 0 otherwise.])],
88 [AC_DEFINE([HAVE_CALLOC_GNU], [0])
91 ])# gl_FUNC_CALLOC_GNU
94 # gl_FUNC_CALLOC_POSIX
95 # --------------------
96 # Test whether 'calloc' is POSIX compliant (sets errno to ENOMEM when it
97 # fails), and replace calloc if it is not.
98 AC_DEFUN([gl_FUNC_CALLOC_POSIX],
100 AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
101 AC_REQUIRE([gl_CHECK_MALLOC_POSIX])
102 if test $gl_cv_func_malloc_posix = yes; then
103 AC_DEFINE([HAVE_CALLOC_POSIX], [1],
104 [Define if the 'calloc' function is POSIX compliant.])