llvm-project/compiler-rt/lib/asan/asan_report.cc

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//===-- asan_report.cc ----------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// This file contains error reporting code.
//===----------------------------------------------------------------------===//
#include "asan_flags.h"
#include "asan_internal.h"
#include "asan_mapping.h"
#include "asan_report.h"
#include "asan_stack.h"
#include "asan_thread.h"
#include "asan_thread_registry.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_report_decorator.h"
namespace __asan {
// -------------------- User-specified callbacks ----------------- {{{1
static void (*error_report_callback)(const char*);
static char *error_message_buffer = 0;
static uptr error_message_buffer_pos = 0;
static uptr error_message_buffer_size = 0;
void AppendToErrorMessageBuffer(const char *buffer) {
if (error_message_buffer) {
uptr length = internal_strlen(buffer);
CHECK_GE(error_message_buffer_size, error_message_buffer_pos);
uptr remaining = error_message_buffer_size - error_message_buffer_pos;
internal_strncpy(error_message_buffer + error_message_buffer_pos,
buffer, remaining);
error_message_buffer[error_message_buffer_size - 1] = '\0';
// FIXME: reallocate the buffer instead of truncating the message.
error_message_buffer_pos += remaining > length ? length : remaining;
}
}
// ---------------------- Decorator ------------------------------ {{{1
bool PrintsToTtyCached() {
static int cached = 0;
static bool prints_to_tty;
if (!cached) { // Ok wrt threads since we are printing only from one thread.
prints_to_tty = PrintsToTty();
cached = 1;
}
return prints_to_tty;
}
class Decorator: private __sanitizer::AnsiColorDecorator {
public:
Decorator() : __sanitizer::AnsiColorDecorator(PrintsToTtyCached()) { }
const char *Warning() { return Red(); }
const char *EndWarning() { return Default(); }
const char *Access() { return Blue(); }
const char *EndAccess() { return Default(); }
const char *Location() { return Green(); }
const char *EndLocation() { return Default(); }
const char *Allocation() { return Magenta(); }
const char *EndAllocation() { return Default(); }
const char *ShadowByte(u8 byte) {
switch (byte) {
case kAsanHeapLeftRedzoneMagic:
case kAsanHeapRightRedzoneMagic:
return Red();
case kAsanHeapFreeMagic:
return Magenta();
case kAsanStackLeftRedzoneMagic:
case kAsanStackMidRedzoneMagic:
case kAsanStackRightRedzoneMagic:
case kAsanStackPartialRedzoneMagic:
return Red();
case kAsanStackAfterReturnMagic:
return Magenta();
case kAsanInitializationOrderMagic:
return Cyan();
case kAsanUserPoisonedMemoryMagic:
return Blue();
case kAsanStackUseAfterScopeMagic:
return Magenta();
case kAsanGlobalRedzoneMagic:
return Red();
case kAsanInternalHeapMagic:
return Yellow();
default:
return Default();
}
}
const char *EndShadowByte() { return Default(); }
};
// ---------------------- Helper functions ----------------------- {{{1
static void PrintShadowByte(const char *before, u8 byte,
const char *after = "\n") {
Decorator d;
Printf("%s%s%x%x%s%s", before,
d.ShadowByte(byte), byte >> 4, byte & 15, d.EndShadowByte(), after);
}
static void PrintShadowBytes(const char *before, u8 *bytes,
u8 *guilty, uptr n) {
Decorator d;
if (before)
Printf("%s%p:", before, bytes);
for (uptr i = 0; i < n; i++) {
u8 *p = bytes + i;
const char *before = p == guilty ? "[" :
p - 1 == guilty ? "" : " ";
const char *after = p == guilty ? "]" : "";
PrintShadowByte(before, *p, after);
}
Printf("\n");
}
static void PrintShadowMemoryForAddress(uptr addr) {
if (!AddrIsInMem(addr))
return;
uptr shadow_addr = MemToShadow(addr);
const uptr n_bytes_per_row = 16;
uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
Printf("Shadow bytes around the buggy address:\n");
for (int i = -5; i <= 5; i++) {
const char *prefix = (i == 0) ? "=>" : " ";
PrintShadowBytes(prefix,
(u8*)(aligned_shadow + i * n_bytes_per_row),
(u8*)shadow_addr, n_bytes_per_row);
}
Printf("Shadow byte legend (one shadow byte represents %d "
"application bytes):\n", (int)SHADOW_GRANULARITY);
PrintShadowByte(" Addressable: ", 0);
Printf(" Partially addressable: ");
for (uptr i = 1; i < SHADOW_GRANULARITY; i++)
PrintShadowByte("", i, " ");
Printf("\n");
PrintShadowByte(" Heap left redzone: ", kAsanHeapLeftRedzoneMagic);
PrintShadowByte(" Heap righ redzone: ", kAsanHeapRightRedzoneMagic);
PrintShadowByte(" Freed Heap region: ", kAsanHeapFreeMagic);
PrintShadowByte(" Stack left redzone: ", kAsanStackLeftRedzoneMagic);
PrintShadowByte(" Stack mid redzone: ", kAsanStackMidRedzoneMagic);
PrintShadowByte(" Stack right redzone: ", kAsanStackRightRedzoneMagic);
PrintShadowByte(" Stack partial redzone: ", kAsanStackPartialRedzoneMagic);
PrintShadowByte(" Stack after return: ", kAsanStackAfterReturnMagic);
PrintShadowByte(" Stack use after scope: ", kAsanStackUseAfterScopeMagic);
PrintShadowByte(" Global redzone: ", kAsanGlobalRedzoneMagic);
PrintShadowByte(" Global init order: ", kAsanInitializationOrderMagic);
PrintShadowByte(" Poisoned by user: ", kAsanUserPoisonedMemoryMagic);
PrintShadowByte(" ASan internal: ", kAsanInternalHeapMagic);
}
static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
const char *zone_name) {
if (zone_ptr) {
if (zone_name) {
Printf("malloc_zone_from_ptr(%p) = %p, which is %s\n",
ptr, zone_ptr, zone_name);
} else {
Printf("malloc_zone_from_ptr(%p) = %p, which doesn't have a name\n",
ptr, zone_ptr);
}
} else {
Printf("malloc_zone_from_ptr(%p) = 0\n", ptr);
}
}
// ---------------------- Address Descriptions ------------------- {{{1
static bool IsASCII(unsigned char c) {
return /*0x00 <= c &&*/ c <= 0x7F;
}
// Check if the global is a zero-terminated ASCII string. If so, print it.
static void PrintGlobalNameIfASCII(const __asan_global &g) {
for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
if (!IsASCII(*(unsigned char*)p)) return;
}
if (*(char*)(g.beg + g.size - 1) != 0) return;
Printf(" '%s' is ascii string '%s'\n", g.name, (char*)g.beg);
}
bool DescribeAddressRelativeToGlobal(uptr addr, const __asan_global &g) {
if (addr < g.beg - kGlobalAndStackRedzone) return false;
if (addr >= g.beg + g.size_with_redzone) return false;
Decorator d;
Printf("%s", d.Location());
Printf("%p is located ", (void*)addr);
if (addr < g.beg) {
Printf("%zd bytes to the left", g.beg - addr);
} else if (addr >= g.beg + g.size) {
Printf("%zd bytes to the right", addr - (g.beg + g.size));
} else {
Printf("%zd bytes inside", addr - g.beg); // Can it happen?
}
Printf(" of global variable '%s' (0x%zx) of size %zu\n",
g.name, g.beg, g.size);
Printf("%s", d.EndLocation());
PrintGlobalNameIfASCII(g);
return true;
}
bool DescribeAddressIfShadow(uptr addr) {
if (AddrIsInMem(addr))
return false;
static const char kAddrInShadowReport[] =
"Address %p is located in the %s.\n";
if (AddrIsInShadowGap(addr)) {
Printf(kAddrInShadowReport, addr, "shadow gap area");
return true;
}
if (AddrIsInHighShadow(addr)) {
Printf(kAddrInShadowReport, addr, "high shadow area");
return true;
}
if (AddrIsInLowShadow(addr)) {
Printf(kAddrInShadowReport, addr, "low shadow area");
return true;
}
CHECK(0 && "Address is not in memory and not in shadow?");
return false;
}
bool DescribeAddressIfStack(uptr addr, uptr access_size) {
AsanThread *t = asanThreadRegistry().FindThreadByStackAddress(addr);
if (!t) return false;
const sptr kBufSize = 4095;
char buf[kBufSize];
uptr offset = 0;
const char *frame_descr = t->GetFrameNameByAddr(addr, &offset);
// This string is created by the compiler and has the following form:
// "FunctioName n alloc_1 alloc_2 ... alloc_n"
// where alloc_i looks like "offset size len ObjectName ".
CHECK(frame_descr);
// Report the function name and the offset.
const char *name_end = internal_strchr(frame_descr, ' ');
CHECK(name_end);
buf[0] = 0;
internal_strncat(buf, frame_descr,
Min(kBufSize,
static_cast<sptr>(name_end - frame_descr)));
Decorator d;
Printf("%s", d.Location());
Printf("Address %p is located at offset %zu "
"in frame <%s> of T%d's stack:\n",
(void*)addr, offset, buf, t->tid());
Printf("%s", d.EndLocation());
// Report the number of stack objects.
char *p;
uptr n_objects = internal_simple_strtoll(name_end, &p, 10);
CHECK(n_objects > 0);
Printf(" This frame has %zu object(s):\n", n_objects);
// Report all objects in this frame.
for (uptr i = 0; i < n_objects; i++) {
uptr beg, size;
sptr len;
beg = internal_simple_strtoll(p, &p, 10);
size = internal_simple_strtoll(p, &p, 10);
len = internal_simple_strtoll(p, &p, 10);
if (beg <= 0 || size <= 0 || len < 0 || *p != ' ') {
Printf("AddressSanitizer can't parse the stack frame "
"descriptor: |%s|\n", frame_descr);
break;
}
p++;
buf[0] = 0;
internal_strncat(buf, p, Min(kBufSize, len));
p += len;
Printf(" [%zu, %zu) '%s'\n", beg, beg + size, buf);
}
Printf("HINT: this may be a false positive if your program uses "
"some custom stack unwind mechanism or swapcontext\n"
" (longjmp and C++ exceptions *are* supported)\n");
DescribeThread(t->summary());
return true;
}
static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
uptr access_size) {
uptr offset;
Decorator d;
Printf("%s", d.Location());
Printf("%p is located ", (void*)addr);
if (chunk.AddrIsInside(addr, access_size, &offset)) {
Printf("%zu bytes inside of", offset);
} else if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
Printf("%zu bytes to the left of", offset);
} else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
Printf("%zu bytes to the right of", offset);
} else {
Printf(" somewhere around (this is AddressSanitizer bug!)");
}
Printf(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
(void*)(chunk.Beg()), (void*)(chunk.End()));
Printf("%s", d.EndLocation());
}
// Return " (thread_name) " or an empty string if the name is empty.
const char *ThreadNameWithParenthesis(AsanThreadSummary *t, char buff[],
uptr buff_len) {
const char *name = t->name();
if (*name == 0) return "";
buff[0] = 0;
internal_strncat(buff, " (", 3);
internal_strncat(buff, name, buff_len - 4);
internal_strncat(buff, ")", 2);
return buff;
}
const char *ThreadNameWithParenthesis(u32 tid, char buff[],
uptr buff_len) {
if (tid == kInvalidTid) return "";
AsanThreadSummary *t = asanThreadRegistry().FindByTid(tid);
return ThreadNameWithParenthesis(t, buff, buff_len);
}
void DescribeHeapAddress(uptr addr, uptr access_size) {
AsanChunkView chunk = FindHeapChunkByAddress(addr);
if (!chunk.IsValid()) return;
DescribeAccessToHeapChunk(chunk, addr, access_size);
CHECK(chunk.AllocTid() != kInvalidTid);
AsanThreadSummary *alloc_thread =
asanThreadRegistry().FindByTid(chunk.AllocTid());
StackTrace alloc_stack;
chunk.GetAllocStack(&alloc_stack);
AsanThread *t = asanThreadRegistry().GetCurrent();
CHECK(t);
char tname[128];
Decorator d;
if (chunk.FreeTid() != kInvalidTid) {
AsanThreadSummary *free_thread =
asanThreadRegistry().FindByTid(chunk.FreeTid());
Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
free_thread->tid(),
ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
d.EndAllocation());
StackTrace free_stack;
chunk.GetFreeStack(&free_stack);
PrintStack(&free_stack);
Printf("%spreviously allocated by thread T%d%s here:%s\n",
d.Allocation(), alloc_thread->tid(),
ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
d.EndAllocation());
PrintStack(&alloc_stack);
DescribeThread(t->summary());
DescribeThread(free_thread);
DescribeThread(alloc_thread);
} else {
Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
alloc_thread->tid(),
ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
d.EndAllocation());
PrintStack(&alloc_stack);
DescribeThread(t->summary());
DescribeThread(alloc_thread);
}
}
void DescribeAddress(uptr addr, uptr access_size) {
// Check if this is shadow or shadow gap.
if (DescribeAddressIfShadow(addr))
return;
CHECK(AddrIsInMem(addr));
if (DescribeAddressIfGlobal(addr))
return;
if (DescribeAddressIfStack(addr, access_size))
return;
// Assume it is a heap address.
DescribeHeapAddress(addr, access_size);
}
// ------------------- Thread description -------------------- {{{1
void DescribeThread(AsanThreadSummary *summary) {
CHECK(summary);
// No need to announce the main thread.
if (summary->tid() == 0 || summary->announced()) {
return;
}
summary->set_announced(true);
char tname[128];
Printf("Thread T%d%s", summary->tid(),
ThreadNameWithParenthesis(summary->tid(), tname, sizeof(tname)));
Printf(" created by T%d%s here:\n",
summary->parent_tid(),
ThreadNameWithParenthesis(summary->parent_tid(),
tname, sizeof(tname)));
PrintStack(summary->stack());
// Recursively described parent thread if needed.
if (flags()->print_full_thread_history) {
AsanThreadSummary *parent_summary =
asanThreadRegistry().FindByTid(summary->parent_tid());
DescribeThread(parent_summary);
}
}
// -------------------- Different kinds of reports ----------------- {{{1
// Use ScopedInErrorReport to run common actions just before and
// immediately after printing error report.
class ScopedInErrorReport {
public:
ScopedInErrorReport() {
static atomic_uint32_t num_calls;
static u32 reporting_thread_tid;
if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
// Do not print more than one report, otherwise they will mix up.
// Error reporting functions shouldn't return at this situation, as
// they are defined as no-return.
Report("AddressSanitizer: while reporting a bug found another one."
"Ignoring.\n");
u32 current_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
if (current_tid != reporting_thread_tid) {
// ASan found two bugs in different threads simultaneously. Sleep
// long enough to make sure that the thread which started to print
// an error report will finish doing it.
SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
}
// If we're still not dead for some reason, use raw Exit() instead of
// Die() to bypass any additional checks.
Exit(flags()->exitcode);
}
ASAN_ON_ERROR();
reporting_thread_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
Printf("===================================================="
"=============\n");
if (reporting_thread_tid != kInvalidTid) {
// We started reporting an error message. Stop using the fake stack
// in case we call an instrumented function from a symbolizer.
AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
CHECK(curr_thread);
curr_thread->fake_stack().StopUsingFakeStack();
}
}
// Destructor is NORETURN, as functions that report errors are.
NORETURN ~ScopedInErrorReport() {
// Make sure the current thread is announced.
AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
if (curr_thread) {
DescribeThread(curr_thread->summary());
}
// Print memory stats.
__asan_print_accumulated_stats();
if (error_report_callback) {
error_report_callback(error_message_buffer);
}
Report("ABORTING\n");
Die();
}
};
void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, uptr addr) {
ScopedInErrorReport in_report;
Decorator d;
Printf("%s", d.Warning());
Report("ERROR: AddressSanitizer: SEGV on unknown address %p"
" (pc %p sp %p bp %p T%d)\n",
(void*)addr, (void*)pc, (void*)sp, (void*)bp,
asanThreadRegistry().GetCurrentTidOrInvalid());
Printf("%s", d.EndWarning());
Printf("AddressSanitizer can not provide additional info.\n");
GET_STACK_TRACE_FATAL(pc, bp);
PrintStack(&stack);
}
void ReportDoubleFree(uptr addr, StackTrace *stack) {
ScopedInErrorReport in_report;
Decorator d;
Printf("%s", d.Warning());
Report("ERROR: AddressSanitizer: attempting double-free on %p:\n", addr);
Printf("%s", d.EndWarning());
PrintStack(stack);
DescribeHeapAddress(addr, 1);
}
void ReportFreeNotMalloced(uptr addr, StackTrace *stack) {
ScopedInErrorReport in_report;
Decorator d;
Printf("%s", d.Warning());
Report("ERROR: AddressSanitizer: attempting free on address "
"which was not malloc()-ed: %p\n", addr);
Printf("%s", d.EndWarning());
PrintStack(stack);
DescribeHeapAddress(addr, 1);
}
void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
ScopedInErrorReport in_report;
Decorator d;
Printf("%s", d.Warning());
Report("ERROR: AddressSanitizer: attempting to call "
"malloc_usable_size() for pointer which is "
"not owned: %p\n", addr);
Printf("%s", d.EndWarning());
PrintStack(stack);
DescribeHeapAddress(addr, 1);
}
void ReportAsanGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
ScopedInErrorReport in_report;
Decorator d;
Printf("%s", d.Warning());
Report("ERROR: AddressSanitizer: attempting to call "
"__asan_get_allocated_size() for pointer which is "
"not owned: %p\n", addr);
Printf("%s", d.EndWarning());
PrintStack(stack);
DescribeHeapAddress(addr, 1);
}
void ReportStringFunctionMemoryRangesOverlap(
const char *function, const char *offset1, uptr length1,
const char *offset2, uptr length2, StackTrace *stack) {
ScopedInErrorReport in_report;
Decorator d;
Printf("%s", d.Warning());
Report("ERROR: AddressSanitizer: %s-param-overlap: "
"memory ranges [%p,%p) and [%p, %p) overlap\n", \
function, offset1, offset1 + length1, offset2, offset2 + length2);
Printf("%s", d.EndWarning());
PrintStack(stack);
DescribeAddress((uptr)offset1, length1);
DescribeAddress((uptr)offset2, length2);
}
// ----------------------- Mac-specific reports ----------------- {{{1
void WarnMacFreeUnallocated(
uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
// Just print a warning here.
Printf("free_common(%p) -- attempting to free unallocated memory.\n"
"AddressSanitizer is ignoring this error on Mac OS now.\n",
addr);
PrintZoneForPointer(addr, zone_ptr, zone_name);
PrintStack(stack);
DescribeHeapAddress(addr, 1);
}
void ReportMacMzReallocUnknown(
uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
ScopedInErrorReport in_report;
Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
"This is an unrecoverable problem, exiting now.\n",
addr);
PrintZoneForPointer(addr, zone_ptr, zone_name);
PrintStack(stack);
DescribeHeapAddress(addr, 1);
}
void ReportMacCfReallocUnknown(
uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
ScopedInErrorReport in_report;
Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
"This is an unrecoverable problem, exiting now.\n",
addr);
PrintZoneForPointer(addr, zone_ptr, zone_name);
PrintStack(stack);
DescribeHeapAddress(addr, 1);
}
} // namespace __asan
// --------------------------- Interface --------------------- {{{1
using namespace __asan; // NOLINT
void __asan_report_error(uptr pc, uptr bp, uptr sp,
uptr addr, bool is_write, uptr access_size) {
ScopedInErrorReport in_report;
// Determine the error type.
const char *bug_descr = "unknown-crash";
if (AddrIsInMem(addr)) {
u8 *shadow_addr = (u8*)MemToShadow(addr);
// If we are accessing 16 bytes, look at the second shadow byte.
if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
shadow_addr++;
// If we are in the partial right redzone, look at the next shadow byte.
if (*shadow_addr > 0 && *shadow_addr < 128)
shadow_addr++;
switch (*shadow_addr) {
case kAsanHeapLeftRedzoneMagic:
case kAsanHeapRightRedzoneMagic:
bug_descr = "heap-buffer-overflow";
break;
case kAsanHeapFreeMagic:
bug_descr = "heap-use-after-free";
break;
case kAsanStackLeftRedzoneMagic:
bug_descr = "stack-buffer-underflow";
break;
case kAsanInitializationOrderMagic:
bug_descr = "initialization-order-fiasco";
break;
case kAsanStackMidRedzoneMagic:
case kAsanStackRightRedzoneMagic:
case kAsanStackPartialRedzoneMagic:
bug_descr = "stack-buffer-overflow";
break;
case kAsanStackAfterReturnMagic:
bug_descr = "stack-use-after-return";
break;
case kAsanUserPoisonedMemoryMagic:
bug_descr = "use-after-poison";
break;
case kAsanStackUseAfterScopeMagic:
bug_descr = "stack-use-after-scope";
break;
case kAsanGlobalRedzoneMagic:
bug_descr = "global-buffer-overflow";
break;
}
}
Decorator d;
Printf("%s", d.Warning());
Report("ERROR: AddressSanitizer: %s on address "
"%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
bug_descr, (void*)addr, pc, bp, sp);
Printf("%s", d.EndWarning());
u32 curr_tid = asanThreadRegistry().GetCurrentTidOrInvalid();
char tname[128];
Printf("%s%s of size %zu at %p thread T%d%s%s\n",
d.Access(),
access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
access_size, (void*)addr, curr_tid,
ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
d.EndAccess());
GET_STACK_TRACE_FATAL(pc, bp);
PrintStack(&stack);
DescribeAddress(addr, access_size);
PrintShadowMemoryForAddress(addr);
}
void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
error_report_callback = callback;
if (callback) {
error_message_buffer_size = 1 << 16;
error_message_buffer =
(char*)MmapOrDie(error_message_buffer_size, __FUNCTION__);
error_message_buffer_pos = 0;
}
}
#if !SANITIZER_SUPPORTS_WEAK_HOOKS
// Provide default implementation of __asan_on_error that does nothing
// and may be overriden by user.
SANITIZER_WEAK_ATTRIBUTE SANITIZER_INTERFACE_ATTRIBUTE NOINLINE
void __asan_on_error() {}
#endif