1# pid_t.m4 serial 4 2dnl Copyright (C) 2020-2021 Free Software Foundation, Inc. 3dnl This file is free software; the Free Software Foundation 4dnl gives unlimited permission to copy and/or distribute it, 5dnl with or without modifications, as long as this notice is preserved. 6 7# The following implementation works around a problem in autoconf <= 2.69. 8m4_version_prereq([2.70], [], [ 9 10dnl Define pid_t if the headers don't define it. 11AC_DEFUN([AC_TYPE_PID_T], 12[ 13 AC_CHECK_TYPE([pid_t], 14 [], 15 [dnl On 64-bit native Windows, define it to the equivalent of 'intptr_t' 16 dnl (= 'long long' = '__int64'), because that is the return type 17 dnl of the _spawnv* functions 18 dnl <https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/spawnvp-wspawnvp> 19 dnl and the argument type of the _cwait function 20 dnl <https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/cwait>. 21 dnl Otherwise (on 32-bit Windows and on old Unix platforms), define it 22 dnl to 'int'. 23 AC_COMPILE_IFELSE( 24 [AC_LANG_PROGRAM([[ 25 #if defined _WIN64 && !defined __CYGWIN__ 26 LLP64 27 #endif 28 ]]) 29 ], 30 [gl_pid_type='int'], 31 [gl_pid_type='__int64']) 32 AC_DEFINE_UNQUOTED([pid_t], [$gl_pid_type], 33 [Define as a signed integer type capable of holding a process identifier.]) 34 ], 35 [AC_INCLUDES_DEFAULT]) 36]) 37 38])# m4_version_prereq 2.70 39