diff --git a/py/objexcept.c b/py/objexcept.c
index a9fe04094149e72560935c872f41ebdc10f4fcc1..0a03df9d035722aa5e5facbbde585a799b2cc51c 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;
+
+ // 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);
+ }
+
+ // 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 {
- o->args = MP_OBJ_TO_PTR(mp_obj_new_tuple(n_args, args));
+ // 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));
+ }
}
- o->base.type = type;
- o->traceback_data = NULL;
- return MP_OBJ_FROM_PTR(o);
+
+ // 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);
-
- // 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;
-
-#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.
+// 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.
- 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;
+struct _exc_printer_t {
+ bool allow_realloc;
+ size_t alloc;
+ size_t len;
+ byte *buf;
+};
- vstr_t vstr;
- vstr_init_fixed_buf(&vstr, max_len, (char *)str_data);
+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 {
+ 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;
+}
- va_list ap;
- va_start(ap, fmt);
- vstr_vprintf(&vstr, fmt, ap);
- va_end(ap);
+mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char *fmt, ...) {
+ assert(fmt != NULL);
- str->base.type = &mp_type_str;
- str->hash = qstr_compute_hash(str_data, str->len);
- str->len = vstr.len;
- str->data = str_data;
+ // Check that the given type is an exception type
+ assert(exc_type->make_new == mp_obj_exception_make_new);
- o->args = tuple;
+ // 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
- size_t offset = &str_data[str->len] - (byte*)MP_STATE_VM(mp_emergency_exception_buf);
- offset += sizeof(void *) - 1;
- offset &= ~(sizeof(void *) - 1);
+ 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 ((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
+ 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 {
- 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);
- } 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);
- }
- }
+ // 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;
}
- return MP_OBJ_FROM_PTR(o);
+ // 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_alloc = 3;
self->traceback_len = 0;
- } else if (self->traceback_len + 3 > self->traceback_alloc) {
+ } 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;
+ }
+ #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 d228e6faab856e22fa655e1bd84ecf2c982114b8..4a9fa18bc17513775067ca09db12b56f8dda2952 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 82b10b5f5448d6bbe0b40de65cedf933b2c3bcad..fd2cfb27225184c28e9a04f669077c88bcbe6c2f 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 866a9b7c3d6900616acb95619489a73c5835e68b..568d99f8e80dc745a96f31d488e1bd09f9655add 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