forked from cory/tildefriends
Cory McWilliams
424b9b5a2f
git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@4490 ed5197a5-7fde-0310-b194-c3ffbd925b24
48 lines
1.5 KiB
Plaintext
48 lines
1.5 KiB
Plaintext
# SYNOPSIS
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#
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# AX_CHECK_CATCHABLE_SEGV
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#
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# DESCRIPTION
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#
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# Check whether segmentation violations can be caught using signal handlers.
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#serial 1
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AC_DEFUN([AX_CHECK_CATCHABLE_SEGV], [dnl
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AC_PREREQ(2.64)
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AS_VAR_PUSHDEF([CACHEVAR], [ax_cv_check_[]_AC_LANG_ABBREV[]CATCHABLE_SEGV])dnl
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AC_CACHE_CHECK([whether segmentation violations can be caught], CACHEVAR, [
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AC_RUN_IFELSE([
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AC_LANG_PROGRAM([[
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#include <signal.h>
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#include <stdlib.h>
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static void sig(int _) { exit(0); }
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]], [[
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volatile unsigned char * volatile x = (volatile unsigned char *) malloc(8);
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size_t i;
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#ifdef SIGPROT
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signal(SIGPROT, sig);
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#endif
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signal(SIGSEGV, sig);
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signal(SIGBUS, sig);
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#if !defined(__SANITIZE_ADDRESS__) && !defined(__EMSCRIPTEN__)
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*((volatile unsigned char *) -1) = 0xd0;
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*((volatile unsigned char *) 1) = 0xd0;
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for (i = 0; i < 10000000; i += 1024) { x[-i] = x[i] = (unsigned char) i; }
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#endif
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free((void *) x);
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exit(1)
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]])],
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[AS_VAR_SET(CACHEVAR, [yes])],
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[AS_VAR_SET(CACHEVAR, [no])],
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[AS_VAR_SET(CACHEVAR, [unknown])]
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)
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])
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AS_VAR_IF(CACHEVAR, yes,
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[AC_DEFINE([HAVE_CATCHABLE_SEGV], [1], [Define if segmentation violations can be caught using signal handlers])],
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[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.])]
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)
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AS_VAR_POPDEF([CACHEVAR])dnl
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])
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