# # Check for supported __attribute__ features # # AC_C_ATTRIBUTE(FEATURE, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND]) # AC_DEFUN([AC_C_ATTRIBUTE], [AS_VAR_PUSHDEF([CACHEVAR], [ax_cv_c_attribute_$1])dnl AC_CACHE_CHECK([for __attribute__ (($1))], CACHEVAR,[ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [[ void foo(void) __attribute__ (($1)); ]])], [AS_VAR_SET(CACHEVAR, [yes])], [AS_VAR_SET(CACHEVAR, [no])])]) AS_VAR_IF(CACHEVAR,yes, [m4_default([$2], :)], [m4_default([$3], :)]) AS_VAR_POPDEF([CACHEVAR])dnl ])dnl