Two days ago, I did:
> 2024-07-17 Bruno Haible <br...@clisp.org>
>
> stack-trace: Use libasan as an alternative to libbacktrace.
> * m4/stack-trace.m4 (gl_STACK_TRACE_EARLY): As a second choice, use
> libasan.
It turns out that this does not work well:
1) When '-lasan' is added to LIBS, many tests fail, e.g.
==103167==ASan runtime does not come first in initial library list; you should
either link runtime to your application or manually preload it with LD_PRELOAD.
FAIL test-acos (exit status: 1)
So, '-lasan' needs to be added to CFLAGS and CXXFLAGS, not LIBS, so that it
occurs _before_ other libraries on the link command line. Recall that the
Automake rule for linking a program is essentially
$(CC) $(AM_CFLAGS) $(CFLAGS) $(AM_LDFLAGS) $(LDFLAGS) -o $@
and both $(AM_LDFLAGS) and $(LDFLAGS) can contain other -l options.
2) With '-lasan' added to CFLAGS, still 29 tests fail. That's because
apparently the address sanitizer gets activated, with default options.
So I set
$ export ASAN_OPTIONS="detect_leaks=0 abort_on_error=1
allocator_may_return_null=1"
3) Still, 5 tests fail:
FAIL: test-dprintf-posix2.sh
FAIL: test-fprintf-posix3.sh
FAIL: test-free
FAIL: test-sigsegv-catch-stackoverflow1
FAIL: test-sigsegv-catch-stackoverflow2
These are "normal" failures from the address sanitizer. But still, it's
undesired, since the user has not asked for a sanitizer in the first place.
That's too much complexity (too many unwanted side effects), when the
more reliable workaround is to just install libbacktrace. I'm therefore
reverting the change.
2024-07-20 Bruno Haible <br...@clisp.org>
stack-trace: Don't use libasan by default.
* m4/stack-trace.m4 (gl_STACK_TRACE_EARLY): Remove libasan as second
choice.
diff --git a/m4/stack-trace.m4 b/m4/stack-trace.m4
index faf86eefe9..43f6ef2abf 100644
--- a/m4/stack-trace.m4
+++ b/m4/stack-trace.m4
@@ -1,5 +1,5 @@
# stack-trace.m4
-# serial 2
+# serial 3
dnl Copyright (C) 2024 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -22,7 +22,6 @@ AC_DEFUN([gl_STACK_TRACE_EARLY]
AC_MSG_RESULT([$enable_debug])
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
- AC_REQUIRE([AC_CANONICAL_HOST])
if test $enable_debug = yes; then
dnl The first choice is libbacktrace by Ian Lance Taylor.
dnl Maintained at https://github.com/ianlancetaylor/libbacktrace,
@@ -49,71 +48,25 @@ AC_DEFUN([gl_STACK_TRACE_EARLY]
CAN_PRINT_STACK_TRACE=1
LIBS="$LIBS -lbacktrace"
else
- dnl The second choice is GCC's libasan, installed as part of GCC.
- dnl It produces source file names and line numbers, if the binary
- dnl is compiled with debug information.
- AC_CACHE_CHECK([for libasan], [gl_cv_lib_asan], [
- gl_saved_LIBS="$LIBS"
- LIBS="$gl_saved_LIBS -lasan"
- dnl We need AC_RUN_IFELSE here, not merely AC_LINK_IFELSE, because on
- dnl NetBSD libasan exists but every program that links to it
immediately
- dnl prints "This sanitizer is not compatible with enabled ASLR" to
- dnl standard error and exits with code 0, without even invoking main().
- AC_RUN_IFELSE(
- [AC_LANG_PROGRAM(
- [[#include <stdio.h>
- extern
- #ifdef __cplusplus
- "C"
- #endif
- void __sanitizer_print_stack_trace (void);
- ]],
- [[remove ("conftest.c");
- __sanitizer_print_stack_trace ();
- ]])],
- [if test -f conftest.c; then
- dnl main() was not reached. NetBSD!
- gl_cv_lib_asan=no
- else
- gl_cv_lib_asan=yes
- fi
- ],
- [gl_cv_lib_asan=no],
- [case "$host_os" in
- netbsd*) gl_cv_lib_asan="guessing no" ;;
- *) gl_cv_lib_asan="guessing yes" ;;
- esac
- ])
- LIBS="$gl_saved_LIBS"
- ])
- case "$gl_cv_lib_asan" in
- *yes)
- AC_DEFINE([HAVE_LIBASAN], [1],
- [Define if you have the libasan library.])
+ dnl The second choice is libexecinfo.
+ dnl It does not produce source file names and line numbers, only
addresses
+ dnl (which are mostly useless due to ASLR) and _sometimes_ function
names.
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ case "$host_os" in
+ *-gnu* | gnu* | darwin* | freebsd* | dragonfly* | netbsd* | openbsd* |
solaris*)
+ dnl execinfo might be implemented on this platform.
CAN_PRINT_STACK_TRACE=1
- LIBS="$LIBS -lasan"
- ;;
- *)
- dnl The third choice is libexecinfo.
- dnl It does not produce source file names and line numbers, only
addresses
- dnl (which are mostly useless due to ASLR) and _sometimes_ function
names.
+ dnl On *BSD system, link all programs with -lexecinfo. Cf.
m4/execinfo.m4.
+ case "$host_os" in
+ freebsd* | dragonfly* | netbsd* | openbsd*)
+ LIBS="$LIBS -lexecinfo"
+ ;;
+ esac
+ dnl Link all programs in such a way that the stack trace includes the
+ dnl function names. '-rdynamic' is equivalent to
'-Wl,-export-dynamic'.
case "$host_os" in
- *-gnu* | gnu* | darwin* | freebsd* | dragonfly* | netbsd* |
openbsd* | solaris*)
- dnl execinfo might be implemented on this platform.
- CAN_PRINT_STACK_TRACE=1
- dnl On *BSD system, link all programs with -lexecinfo. Cf.
m4/execinfo.m4.
- case "$host_os" in
- freebsd* | dragonfly* | netbsd* | openbsd*)
- LIBS="$LIBS -lexecinfo"
- ;;
- esac
- dnl Link all programs in such a way that the stack trace
includes the
- dnl function names. '-rdynamic' is equivalent to
'-Wl,-export-dynamic'.
- case "$host_os" in
- *-gnu* | gnu* | openbsd*)
- LDFLAGS="$LDFLAGS -rdynamic"
- ;;
- esac
+ *-gnu* | gnu* | openbsd*)
+ LDFLAGS="$LDFLAGS -rdynamic"
;;
esac
;;
