1dnl Determine whether the current compiler is Clang. 2dnl 3dnl If the current compiler is Clang, set the shell variable CLANG to yes. 4dnl 5dnl The canonical version of this file is maintained in the rra-c-util 6dnl package, available at <https://www.eyrie.org/~eagle/software/rra-c-util/>. 7dnl 8dnl Copyright 2015 Russ Allbery <eagle@eyrie.org> 9dnl 10dnl This file is free software; the authors give unlimited permission to copy 11dnl and/or distribute it, with or without modifications, as long as this 12dnl notice is preserved. 13dnl 14dnl SPDX-License-Identifier: FSFULLR 15 16dnl Source used by RRA_PROG_CC_CLANG. 17AC_DEFUN([_RRA_PROG_CC_CLANG_SOURCE], [[ 18#if ! __clang__ 19#error 20#endif 21]]) 22 23AC_DEFUN([RRA_PROG_CC_CLANG], 24[AC_CACHE_CHECK([if the compiler is Clang], [rra_cv_prog_cc_clang], 25 [AC_COMPILE_IFELSE([AC_LANG_SOURCE([_RRA_PROG_CC_CLANG_SOURCE])], 26 [rra_cv_prog_cc_clang=yes], 27 [rra_cv_prog_cc_clang=no])]) 28 AS_IF([test x"$rra_cv_prog_cc_clang" = xyes], [CLANG=yes])]) 29