diff --git a/m4/curl-functions.m4 b/m4/curl-functions.m4 index ec406f56ae..f3e12a53a9 100644 --- a/m4/curl-functions.m4 +++ b/m4/curl-functions.m4 @@ -6570,24 +6570,26 @@ AC_DEFUN([CURL_COVERAGE],[ ]) dnl CURL_ATOMIC -dnl -------------------------------------------------- -dnl Check if _Atomic works +dnl ------------------------------------------------------------- +dnl Check if _Atomic works. But only check if stdatomic.h exists. dnl AC_DEFUN([CURL_ATOMIC],[ - AC_MSG_CHECKING([if _Atomic is available]) - AC_COMPILE_IFELSE([ - AC_LANG_PROGRAM([[ - $curl_includes_unistd - ]],[[ - _Atomic int i = 0; - ]]) - ],[ - AC_MSG_RESULT([yes]) - AC_DEFINE_UNQUOTED(HAVE_ATOMIC, 1, - [Define to 1 if you have _Atomic support.]) - tst_atomic="yes" - ],[ - AC_MSG_RESULT([no]) - tst_atomic="no" + AC_CHECK_HEADERS(stdatomic.h, [ + AC_MSG_CHECKING([if _Atomic is available]) + AC_COMPILE_IFELSE([ + AC_LANG_PROGRAM([[ + $curl_includes_unistd + ]],[[ + _Atomic int i = 0; + ]]) + ],[ + AC_MSG_RESULT([yes]) + AC_DEFINE_UNQUOTED(HAVE_ATOMIC, 1, + [Define to 1 if you have _Atomic support.]) + tst_atomic="yes" + ],[ + AC_MSG_RESULT([no]) + tst_atomic="no" + ]) ]) ])