FreeBSD/Linux Kernel Cross Reference
sys/contrib/libsodium/m4/ax_check_catchable_segv.m4

     # SYNOPSIS
     #
     #   AX_CHECK_CATCHABLE_SEGV
     #
     # DESCRIPTION
     #
     #  Check whether segmentation violations can be caught using signal handlers.
     
     #serial 1
    
    AC_DEFUN([AX_CHECK_CATCHABLE_SEGV], [dnl
        AC_PREREQ(2.64)
        AS_VAR_PUSHDEF([CACHEVAR], [ax_cv_check_[]_AC_LANG_ABBREV[]CATCHABLE_SEGV])dnl
        AC_CACHE_CHECK([whether segmentation violations can be caught when using the _AC_LANG compiler], CACHEVAR, [
            AC_RUN_IFELSE([
                AC_LANG_PROGRAM([[
    #include <signal.h>
    #include <stdlib.h>
    static void sig(int _) { exit(0); }
                ]], [[
    volatile unsigned char * volatile x = (volatile unsigned char *) malloc(8);
    size_t i;
    
    signal(SIGSEGV, sig);
    signal(SIGBUS, sig);
    #if !defined(__SANITIZE_ADDRESS__) && !defined(__EMSCRIPTEN__)
    for (i = 0; i < 10000000; i += 1024) { x[-i] = x[i] = (unsigned char) i; }
    #endif
    free((void *) x);
    exit(1)
                ]])],
                [AS_VAR_SET(CACHEVAR, [yes])],
                [AS_VAR_SET(CACHEVAR, [no])],
                [AS_VAR_SET(CACHEVAR, [unknown])]
            )
        ])
        AS_VAR_IF(CACHEVAR, yes,
            [AC_DEFINE([HAVE_CATCHABLE_SEGV], [1], [Define if segmentation violations can be caught using signal handlers])],
            [AC_MSG_WARN([On this platform, segmentation violations cannot be caught using signal handlers. This is expected if you enabled a tool such as Address Sanitizer (-fsanitize=address), but be aware that using Address Sanitizer may also significantly reduce performance.])]
        )
        AS_VAR_POPDEF([CACHEVAR])dnl
    ])

Cache object: 39ce4e1fdcdad1070227f7432012b3f1