1# SYNOPSIS 2# 3# AX_CHECK_CATCHABLE_SEGV 4# 5# DESCRIPTION 6# 7# Check whether segmentation violations can be caught using signal handlers. 8 9#serial 1 10 11AC_DEFUN([AX_CHECK_CATCHABLE_SEGV], [dnl 12 AC_PREREQ(2.64) 13 AS_VAR_PUSHDEF([CACHEVAR], [ax_cv_check_[]_AC_LANG_ABBREV[]CATCHABLE_SEGV])dnl 14 AC_CACHE_CHECK([whether segmentation violations can be caught when using the _AC_LANG compiler], CACHEVAR, [ 15 AC_RUN_IFELSE([ 16 AC_LANG_PROGRAM([[ 17#include <signal.h> 18#include <stdlib.h> 19static void sig(int _) { exit(0); } 20 ]], [[ 21volatile unsigned char * volatile x = (volatile unsigned char *) malloc(8); 22size_t i; 23 24signal(SIGSEGV, sig); 25signal(SIGBUS, sig); 26#if !defined(__SANITIZE_ADDRESS__) && !defined(__EMSCRIPTEN__) 27for (i = 0; i < 10000000; i += 1024) { x[-i] = x[i] = (unsigned char) i; } 28#endif 29free((void *) x); 30exit(1) 31 ]])], 32 [AS_VAR_SET(CACHEVAR, [yes])], 33 [AS_VAR_SET(CACHEVAR, [no])], 34 [AS_VAR_SET(CACHEVAR, [unknown])] 35 ) 36 ]) 37 AS_VAR_IF(CACHEVAR, yes, 38 [AC_DEFINE([HAVE_CATCHABLE_SEGV], [1], [Define if segmentation violations can be caught using signal handlers])], 39 [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.])] 40 ) 41 AS_VAR_POPDEF([CACHEVAR])dnl 42]) 43