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/* Copyright (c) 2012-2019, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#include "orconfig.h"
#include <stdio.h>
#include <stdlib.h>
/* To prevent 'assert' from going away. */
#undef TOR_COVERAGE
#include "core/or/or.h"
#include "lib/err/backtrace.h"
#include "lib/log/log.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
/* -1: no crash.
* 0: crash with a segmentation fault.
* 1x: crash with an assertion failure. */
static int crashtype = 0;
#ifdef __GNUC__
#define NOINLINE __attribute__((noinline))
#endif
int crash(int x) NOINLINE;
int oh_what(int x) NOINLINE;
int a_tangled_web(int x) NOINLINE;
int we_weave(int x) NOINLINE;
#ifdef HAVE_CFLAG_WNULL_DEREFERENCE
DISABLE_GCC_WARNING(null-dereference)
#endif
int
crash(int x)
{
if (crashtype == 0) {
#if defined(__clang_analyzer__) || defined(__COVERITY__)
tor_assert(1 == 0); /* Avert your eyes, clangalyzer and coverity! You
* don't need to see us dereference NULL. */
#else
*(volatile int *)0 = 0;
#endif /* defined(__clang_analyzer__) || defined(__COVERITY__) */
} else if (crashtype == 1) {
tor_assert(1 == 0);
} else if (crashtype == -1) {
;
}
crashtype *= x;
return crashtype;
}
#ifdef HAVE_CFLAG_WNULL_DEREFERENCE
ENABLE_GCC_WARNING(null-dereference)
#endif
int
oh_what(int x)
{
/* We call crash() twice here, so that the compiler won't try to do a
* tail-call optimization. Only the first call will actually happen, but
* telling the compiler to maybe do the second call will prevent it from
* replacing the first call with a jump. */
return crash(x) + crash(x*2);
}
int
a_tangled_web(int x)
{
return oh_what(x) * 99 + oh_what(x);
}
int
we_weave(int x)
{
return a_tangled_web(x) + a_tangled_web(x+1);
}
int
main(int argc, char **argv)
{
log_severity_list_t severity;
if (argc < 2) {
puts("I take an argument. It should be \"assert\" or \"crash\" or "
"\"backtraces\" or \"none\"");
return 1;
}
#if !(defined(HAVE_EXECINFO_H) && defined(HAVE_BACKTRACE) && \
defined(HAVE_BACKTRACE_SYMBOLS_FD) && defined(HAVE_SIGACTION))
puts("Backtrace reporting is not supported on this platform");
return 77;
#endif
if (!strcmp(argv[1], "assert")) {
crashtype = 1;
} else if (!strcmp(argv[1], "crash")) {
crashtype = 0;
} else if (!strcmp(argv[1], "none")) {
crashtype = -1;
} else if (!strcmp(argv[1], "backtraces")) {
return 0;
} else {
puts("Argument should be \"assert\" or \"crash\" or \"none\"");
return 1;
}
init_logging(1);
set_log_severity_config(LOG_WARN, LOG_ERR, &severity);
add_stream_log(&severity, "stdout", STDOUT_FILENO);
tor_log_update_sigsafe_err_fds();
configure_backtrace_handler(NULL);
printf("%d\n", we_weave(2));
clean_up_backtrace_handler();
logs_free_all();
return 0;
}
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