diff --git a/py/objexcept.c b/py/objexcept.c index a9fe04094..0a03df9d0 100644 --- a/py/objexcept.c +++ b/py/objexcept.c @@ -38,6 +38,12 @@ #include "py/gc.h" #include "py/mperrno.h" +// Number of items per traceback entry (file, line, block) +#define TRACEBACK_ENTRY_LEN (3) + +// Number of traceback entries to reserve in the emergency exception buffer +#define EMG_TRACEBACK_ALLOC (2 * TRACEBACK_ENTRY_LEN) + // Instance of MemoryError exception - needed by mp_malloc_fail const mp_obj_exception_t mp_const_MemoryError_obj = {{&mp_type_MemoryError}, 0, 0, NULL, (mp_obj_tuple_t*)&mp_const_empty_tuple_obj}; @@ -127,18 +133,51 @@ STATIC void mp_obj_exception_print(const mp_print_t *print, mp_obj_t o_in, mp_pr mp_obj_t mp_obj_exception_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) { mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, false); - mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 0); - if (o == NULL) { - // Couldn't allocate heap memory; use local data instead. - o = &MP_STATE_VM(mp_emergency_exception_obj); - // We can't store any args. - o->args = (mp_obj_tuple_t*)&mp_const_empty_tuple_obj; - } else { - o->args = MP_OBJ_TO_PTR(mp_obj_new_tuple(n_args, args)); + + // Try to allocate memory for the exception, with fallback to emergency exception object + mp_obj_exception_t *o_exc = m_new_obj_maybe(mp_obj_exception_t); + if (o_exc == NULL) { + o_exc = &MP_STATE_VM(mp_emergency_exception_obj); } - o->base.type = type; - o->traceback_data = NULL; - return MP_OBJ_FROM_PTR(o); + + // Populate the exception object + o_exc->base.type = type; + o_exc->traceback_data = NULL; + + mp_obj_tuple_t *o_tuple; + if (n_args == 0) { + // No args, can use the empty tuple straightaway + o_tuple = (mp_obj_tuple_t*)&mp_const_empty_tuple_obj; + } else { + // Try to allocate memory for the tuple containing the args + o_tuple = m_new_obj_var_maybe(mp_obj_tuple_t, mp_obj_t, n_args); + + #if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF + // If we are called by mp_obj_new_exception_msg_varg then it will have + // reserved room (after the traceback data) for a tuple with 1 element. + // Otherwise we are free to use the whole buffer after the traceback data. + if (o_tuple == NULL && mp_emergency_exception_buf_size >= + EMG_TRACEBACK_ALLOC * sizeof(size_t) + sizeof(mp_obj_tuple_t) + n_args * sizeof(mp_obj_t)) { + o_tuple = (mp_obj_tuple_t*) + ((uint8_t*)MP_STATE_VM(mp_emergency_exception_buf) + EMG_TRACEBACK_ALLOC * sizeof(size_t)); + } + #endif + + if (o_tuple == NULL) { + // No memory for a tuple, fallback to an empty tuple + o_tuple = (mp_obj_tuple_t*)&mp_const_empty_tuple_obj; + } else { + // Have memory for a tuple so populate it + o_tuple->base.type = &mp_type_tuple; + o_tuple->len = n_args; + memcpy(o_tuple->items, args, n_args * sizeof(mp_obj_t)); + } + } + + // Store the tuple of args in the exception object + o_exc->args = o_tuple; + + return MP_OBJ_FROM_PTR(o_exc); } // Get exception "value" - that is, first argument, or None @@ -306,87 +345,95 @@ mp_obj_t mp_obj_new_exception_msg(const mp_obj_type_t *exc_type, const char *msg return mp_obj_new_exception_msg_varg(exc_type, msg); } -mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char *fmt, ...) { - // check that the given type is an exception type - assert(exc_type->make_new == mp_obj_exception_make_new); +// The following struct and function implement a simple printer that conservatively +// allocates memory and truncates the output data if no more memory can be obtained. +// It leaves room for a null byte at the end of the buffer. - // make exception object - mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 0); - if (o == NULL) { - // Couldn't allocate heap memory; use local data instead. - // Unfortunately, we won't be able to format the string... - o = &MP_STATE_VM(mp_emergency_exception_obj); - o->base.type = exc_type; - o->traceback_data = NULL; - o->args = (mp_obj_tuple_t*)&mp_const_empty_tuple_obj; +struct _exc_printer_t { + bool allow_realloc; + size_t alloc; + size_t len; + byte *buf; +}; -#if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF - // If the user has provided a buffer, then we try to create a tuple - // of length 1, which has a string object and the string data. - - if (mp_emergency_exception_buf_size > (sizeof(mp_obj_tuple_t) + sizeof(mp_obj_str_t) + sizeof(mp_obj_t))) { - mp_obj_tuple_t *tuple = (mp_obj_tuple_t *)MP_STATE_VM(mp_emergency_exception_buf); - mp_obj_str_t *str = (mp_obj_str_t *)&tuple->items[1]; - - tuple->base.type = &mp_type_tuple; - tuple->len = 1; - tuple->items[0] = MP_OBJ_FROM_PTR(str); - - byte *str_data = (byte *)&str[1]; - size_t max_len = (byte*)MP_STATE_VM(mp_emergency_exception_buf) + mp_emergency_exception_buf_size - - str_data; - - vstr_t vstr; - vstr_init_fixed_buf(&vstr, max_len, (char *)str_data); - - va_list ap; - va_start(ap, fmt); - vstr_vprintf(&vstr, fmt, ap); - va_end(ap); - - str->base.type = &mp_type_str; - str->hash = qstr_compute_hash(str_data, str->len); - str->len = vstr.len; - str->data = str_data; - - o->args = tuple; - - size_t offset = &str_data[str->len] - (byte*)MP_STATE_VM(mp_emergency_exception_buf); - offset += sizeof(void *) - 1; - offset &= ~(sizeof(void *) - 1); - - if ((mp_emergency_exception_buf_size - offset) > (sizeof(o->traceback_data[0]) * 3)) { - // We have room to store some traceback. - o->traceback_data = (size_t*)((byte *)MP_STATE_VM(mp_emergency_exception_buf) + offset); - o->traceback_alloc = ((byte*)MP_STATE_VM(mp_emergency_exception_buf) + mp_emergency_exception_buf_size - (byte *)o->traceback_data) / sizeof(o->traceback_data[0]); - o->traceback_len = 0; - } - } -#endif // MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF - } else { - o->base.type = exc_type; - o->traceback_data = NULL; - o->args = MP_OBJ_TO_PTR(mp_obj_new_tuple(1, NULL)); - - assert(fmt != NULL); - { - if (strchr(fmt, '%') == NULL) { - // no formatting substitutions, avoid allocating vstr. - o->args->items[0] = mp_obj_new_str(fmt, strlen(fmt), false); +STATIC void exc_add_strn(void *data, const char *str, size_t len) { + struct _exc_printer_t *pr = data; + if (pr->len + len >= pr->alloc) { + // Not enough room for data plus a null byte so try to grow the buffer + if (pr->allow_realloc) { + size_t new_alloc = pr->alloc + len + 16; + byte *new_buf = m_renew_maybe(byte, pr->buf, pr->alloc, new_alloc, true); + if (new_buf == NULL) { + pr->allow_realloc = false; + len = pr->alloc - pr->len - 1; } else { - // render exception message and store as .args[0] - va_list ap; - vstr_t vstr; - vstr_init(&vstr, 16); - va_start(ap, fmt); - vstr_vprintf(&vstr, fmt, ap); - va_end(ap); - o->args->items[0] = mp_obj_new_str_from_vstr(&mp_type_str, &vstr); + pr->alloc = new_alloc; + pr->buf = new_buf; } + } else { + len = pr->alloc - pr->len - 1; } } + memcpy(pr->buf + pr->len, str, len); + pr->len += len; +} - return MP_OBJ_FROM_PTR(o); +mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char *fmt, ...) { + assert(fmt != NULL); + + // Check that the given type is an exception type + assert(exc_type->make_new == mp_obj_exception_make_new); + + // Try to allocate memory for the message + mp_obj_str_t *o_str = m_new_obj_maybe(mp_obj_str_t); + size_t o_str_alloc = strlen(fmt) + 1; + byte *o_str_buf = m_new_maybe(byte, o_str_alloc); + + bool used_emg_buf = false; + #if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF + // If memory allocation failed and there is an emergency buffer then try to use + // that buffer to store the string object and its data (at least 16 bytes for + // the string data), reserving room at the start for the traceback and 1-tuple. + if ((o_str == NULL || o_str_buf == NULL) + && mp_emergency_exception_buf_size >= EMG_TRACEBACK_ALLOC * sizeof(size_t) + + sizeof(mp_obj_tuple_t) + sizeof(mp_obj_t) + sizeof(mp_obj_str_t) + 16) { + used_emg_buf = true; + o_str = (mp_obj_str_t*)((uint8_t*)MP_STATE_VM(mp_emergency_exception_buf) + + EMG_TRACEBACK_ALLOC * sizeof(size_t) + sizeof(mp_obj_tuple_t) + sizeof(mp_obj_t)); + o_str_buf = (byte*)&o_str[1]; + o_str_alloc = (uint8_t*)MP_STATE_VM(mp_emergency_exception_buf) + + mp_emergency_exception_buf_size - o_str_buf; + } + #endif + + if (o_str == NULL) { + // No memory for the string object so create the exception with no args + return mp_obj_exception_make_new(exc_type, 0, 0, NULL); + } + + if (o_str_buf == NULL) { + // No memory for the string buffer: assume that the fmt string is in ROM + // and use that data as the data of the string + o_str->len = o_str_alloc - 1; // will be equal to strlen(fmt) + o_str->data = (const byte*)fmt; + } else { + // We have some memory to format the string + struct _exc_printer_t exc_pr = {!used_emg_buf, o_str_alloc, 0, o_str_buf}; + mp_print_t print = {&exc_pr, exc_add_strn}; + va_list ap; + va_start(ap, fmt); + mp_vprintf(&print, fmt, ap); + va_end(ap); + exc_pr.buf[exc_pr.len] = '\0'; + o_str->len = exc_pr.len; + o_str->data = exc_pr.buf; + } + + // Create the string object and call mp_obj_exception_make_new to create the exception + o_str->base.type = &mp_type_str; + o_str->hash = qstr_compute_hash(o_str->data, o_str->len); + mp_obj_t arg = MP_OBJ_FROM_PTR(o_str); + return mp_obj_exception_make_new(exc_type, 1, 0, &arg); } // return true if the given object is an exception type @@ -443,24 +490,46 @@ void mp_obj_exception_add_traceback(mp_obj_t self_in, qstr file, size_t line, qs // if memory allocation fails (eg because gc is locked), just return if (self->traceback_data == NULL) { - self->traceback_data = m_new_maybe(size_t, 3); + self->traceback_data = m_new_maybe(size_t, TRACEBACK_ENTRY_LEN); if (self->traceback_data == NULL) { + #if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF + if (mp_emergency_exception_buf_size >= EMG_TRACEBACK_ALLOC * sizeof(size_t)) { + // There is room in the emergency buffer for traceback data + size_t *tb = (size_t*)MP_STATE_VM(mp_emergency_exception_buf); + self->traceback_data = tb; + self->traceback_alloc = EMG_TRACEBACK_ALLOC; + } else { + // Can't allocate and no room in emergency buffer + return; + } + #else + // Can't allocate + return; + #endif + } else { + // Allocated the traceback data on the heap + self->traceback_alloc = TRACEBACK_ENTRY_LEN; + } + self->traceback_len = 0; + } else if (self->traceback_len + TRACEBACK_ENTRY_LEN > self->traceback_alloc) { + #if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF + if (self->traceback_data == (size_t*)MP_STATE_VM(mp_emergency_exception_buf)) { + // Can't resize the emergency buffer return; } - self->traceback_alloc = 3; - self->traceback_len = 0; - } else if (self->traceback_len + 3 > self->traceback_alloc) { + #endif // be conservative with growing traceback data - size_t *tb_data = m_renew_maybe(size_t, self->traceback_data, self->traceback_alloc, self->traceback_alloc + 3, true); + size_t *tb_data = m_renew_maybe(size_t, self->traceback_data, self->traceback_alloc, + self->traceback_alloc + TRACEBACK_ENTRY_LEN, true); if (tb_data == NULL) { return; } self->traceback_data = tb_data; - self->traceback_alloc += 3; + self->traceback_alloc += TRACEBACK_ENTRY_LEN; } size_t *tb_data = &self->traceback_data[self->traceback_len]; - self->traceback_len += 3; + self->traceback_len += TRACEBACK_ENTRY_LEN; tb_data[0] = file; tb_data[1] = line; tb_data[2] = block; diff --git a/tests/micropython/emg_exc.py b/tests/micropython/emg_exc.py index d228e6faa..4a9fa18bc 100644 --- a/tests/micropython/emg_exc.py +++ b/tests/micropython/emg_exc.py @@ -2,6 +2,11 @@ import micropython import sys +try: + import uio +except ImportError: + print("SKIP") + raise SystemExit # some ports need to allocate heap for the emg exc try: @@ -14,7 +19,16 @@ def f(): try: raise ValueError(1) except ValueError as er: - sys.print_exception(er) + exc = er micropython.heap_unlock() + # print the exception + buf = uio.StringIO() + sys.print_exception(exc, buf) + for l in buf.getvalue().split("\n"): + if l.startswith(" File "): + print(l.split('"')[2]) + else: + print(l) + f() diff --git a/tests/micropython/emg_exc.py.exp b/tests/micropython/emg_exc.py.exp index 82b10b5f5..fd2cfb272 100644 --- a/tests/micropython/emg_exc.py.exp +++ b/tests/micropython/emg_exc.py.exp @@ -1 +1,4 @@ -ValueError: +Traceback (most recent call last): +, line 20, in f +ValueError: 1 + diff --git a/tests/run-tests b/tests/run-tests index 866a9b7c3..568d99f8e 100755 --- a/tests/run-tests +++ b/tests/run-tests @@ -345,6 +345,7 @@ def run_tests(pyb, tests, args, base_path="."): skip_tests.add('misc/rge_sm.py') # requires yield skip_tests.add('misc/print_exception.py') # because native doesn't have proper traceback info skip_tests.add('misc/sys_exc_info.py') # sys.exc_info() is not supported for native + skip_tests.add('micropython/emg_exc.py') # because native doesn't have proper traceback info skip_tests.add('micropython/heapalloc_traceback.py') # because native doesn't have proper traceback info skip_tests.add('micropython/heapalloc_iter.py') # requires generators skip_tests.add('micropython/schedule.py') # native code doesn't check pending events