Commit 4852e09c authored by Damien George's avatar Damien George
Browse files

py: Fix adding of traceback so that it appends to existing info.

This makes exception traceback info self contained (ie doesn't rely on
list object, which was a bit of a hack), reduces code size, and reduces
RAM footprint of exception by eliminating the list object.

Addresses part of issue #1126.
parent d155fecf
......@@ -38,7 +38,7 @@
#include "py/gc.h"
// Instance of MemoryError exception - needed by mp_malloc_fail
const mp_obj_exception_t mp_const_MemoryError_obj = {{&mp_type_MemoryError}, MP_OBJ_NULL, mp_const_empty_tuple};
const mp_obj_exception_t mp_const_MemoryError_obj = {{&mp_type_MemoryError}, 0, 0, MP_OBJ_NULL, mp_const_empty_tuple};
// Optionally allocated buffer for storing the first argument of an exception
// allocated when the heap is locked.
......@@ -88,7 +88,7 @@ mp_obj_t mp_alloc_emergency_exception_buf(mp_obj_t size_in) {
// Instance of GeneratorExit exception - needed by generator.close()
// This would belong to objgenerator.c, but to keep mp_obj_exception_t
// definition module-private so far, have it here.
const mp_obj_exception_t mp_const_GeneratorExit_obj = {{&mp_type_GeneratorExit}, MP_OBJ_NULL, mp_const_empty_tuple};
const mp_obj_exception_t mp_const_GeneratorExit_obj = {{&mp_type_GeneratorExit}, 0, 0, MP_OBJ_NULL, mp_const_empty_tuple};
STATIC void mp_obj_exception_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
mp_obj_exception_t *o = o_in;
......@@ -126,7 +126,7 @@ mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t
o->args = mp_obj_new_tuple(n_args, args);
}
o->base.type = type_in;
o->traceback = MP_OBJ_NULL;
o->traceback_data = NULL;
return o;
}
......@@ -298,7 +298,7 @@ mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char
// 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 = MP_OBJ_NULL;
o->traceback_data = NULL;
o->args = mp_const_empty_tuple;
#if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF
......@@ -332,21 +332,17 @@ mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char
offset += sizeof(void *) - 1;
offset &= ~(sizeof(void *) - 1);
if ((mp_emergency_exception_buf_size - offset) > (sizeof(mp_obj_list_t) + sizeof(mp_obj_t) * 3)) {
if ((mp_emergency_exception_buf_size - offset) > (sizeof(mp_uint_t) * 3)) {
// We have room to store some traceback.
mp_obj_list_t *list = (mp_obj_list_t *)((byte *)MP_STATE_VM(mp_emergency_exception_buf) + offset);
list->base.type = &mp_type_list;
list->items = (mp_obj_t)&list[1];
list->alloc = (MP_STATE_VM(mp_emergency_exception_buf) + mp_emergency_exception_buf_size - (byte *)list->items) / sizeof(list->items[0]);
list->len = 0;
o->traceback = list;
o->traceback_data = (mp_uint_t*)((byte *)MP_STATE_VM(mp_emergency_exception_buf) + offset);
o->traceback_alloc = (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 = MP_OBJ_NULL;
o->traceback_data = NULL;
o->args = mp_obj_new_tuple(1, NULL);
if (fmt == NULL) {
......@@ -416,50 +412,47 @@ void mp_obj_exception_clear_traceback(mp_obj_t self_in) {
GET_NATIVE_EXCEPTION(self, self_in);
// just set the traceback to the null object
// we don't want to call any memory management functions here
self->traceback = MP_OBJ_NULL;
self->traceback_data = NULL;
}
void mp_obj_exception_add_traceback(mp_obj_t self_in, qstr file, mp_uint_t line, qstr block) {
GET_NATIVE_EXCEPTION(self, self_in);
#if MICROPY_ENABLE_GC
if (gc_is_locked()) {
if (self->traceback == MP_OBJ_NULL) {
// We can't allocate any memory, and no memory has been
// pre-allocated, so there is nothing else we can do.
// append this traceback info to traceback data
// if memory allocation fails (eg because gc is locked), just return
if (self->traceback_data == NULL) {
self->traceback_data = m_new_maybe(mp_uint_t, 3);
if (self->traceback_data == NULL) {
return;
}
mp_obj_list_t *list = self->traceback;
if (list->alloc <= (list->len + 3)) {
// There is some preallocated memory, but not enough to store an
// entire record.
self->traceback_alloc = 3;
self->traceback_len = 0;
} else if (self->traceback_len + 3 > self->traceback_alloc) {
// be conservative with growing traceback data
mp_uint_t *tb_data = m_renew_maybe(mp_uint_t, self->traceback_data, self->traceback_alloc, self->traceback_alloc + 3);
if (tb_data == NULL) {
return;
}
self->traceback_data = tb_data;
self->traceback_alloc += 3;
}
#endif
// for traceback, we are just using the list object for convenience, it's not really a list of Python objects
if (self->traceback == MP_OBJ_NULL) {
self->traceback = mp_obj_new_list_maybe(3);
if (self->traceback == MP_OBJ_NULL) {
return;
}
}
mp_obj_list_t *list = self->traceback;
list->items[0] = (mp_obj_t)(mp_uint_t)file;
list->items[1] = (mp_obj_t)(mp_uint_t)line;
list->items[2] = (mp_obj_t)(mp_uint_t)block;
mp_uint_t *tb_data = &self->traceback_data[self->traceback_len];
self->traceback_len += 3;
tb_data[0] = (mp_uint_t)file;
tb_data[1] = (mp_uint_t)line;
tb_data[2] = (mp_uint_t)block;
}
void mp_obj_exception_get_traceback(mp_obj_t self_in, mp_uint_t *n, mp_uint_t **values) {
GET_NATIVE_EXCEPTION(self, self_in);
if (self->traceback == MP_OBJ_NULL) {
if (self->traceback_data == NULL) {
*n = 0;
*values = NULL;
} else {
mp_uint_t n2;
mp_obj_list_get(self->traceback, &n2, (mp_obj_t**)values);
*n = n2;
*n = self->traceback_len;
*values = self->traceback_data;
}
}
......@@ -31,7 +31,9 @@
typedef struct _mp_obj_exception_t {
mp_obj_base_t base;
mp_obj_t traceback; // a list object, holding (file,line,block) as numbers (not Python objects); a hack for now
mp_uint_t traceback_alloc : (BITS_PER_WORD / 2);
mp_uint_t traceback_len : (BITS_PER_WORD / 2);
mp_uint_t *traceback_data;
mp_obj_tuple_t *args;
} mp_obj_exception_t;
......
......@@ -477,25 +477,6 @@ mp_obj_t mp_obj_new_list(mp_uint_t n, mp_obj_t *items) {
return o;
}
// Special method for usage with exceptions
// Doesn't initialize items, assumes they will be initialized by client.
mp_obj_t mp_obj_new_list_maybe(mp_uint_t n) {
mp_obj_list_t *o = m_new_obj_maybe(mp_obj_list_t);
if (!o) {
return o;
}
o->items = m_new_maybe(mp_obj_t, n);
if (!o->items) {
m_del_obj(mp_obj_list_t, o);
return MP_OBJ_NULL;
}
o->base.type = &mp_type_list;
o->len = o->alloc = n;
return o;
}
void mp_obj_list_get(mp_obj_t self_in, mp_uint_t *len, mp_obj_t **items) {
mp_obj_list_t *self = self_in;
*len = self->len;
......
......@@ -35,6 +35,4 @@ typedef struct _mp_obj_list_t {
mp_obj_t *items;
} mp_obj_list_t;
mp_obj_t mp_obj_new_list_maybe(mp_uint_t n);
#endif // __MICROPY_INCLUDED_PY_OBJLIST_H__
......@@ -6,19 +6,35 @@ else:
import traceback
print_exception = lambda e, f: traceback.print_exception(None, e, None, file=f)
try:
XXX
except Exception as e:
print('caught')
def print_exc(e):
buf = io.StringIO()
print_exception(e, buf)
s = buf.getvalue()
for l in s.split("\n"):
# uPy on pyboard prints <stdin> as file, so remove filename.
if l.startswith(" File "):
print(l[:8], l[-23:])
l = l.split('"')
print(l[0], l[2])
# uPy and CPy tracebacks differ in that CPy prints a source line for
# each traceback entry. In this case, we know that offending line
# has 4-space indent, so filter it out.
elif not l.startswith(" "):
print(l)
# basic exception message
try:
XXX
except Exception as e:
print('caught')
print_exc(e)
# exception message with more than 1 source-code line
def f():
g()
def g():
YYY
try:
f()
except Exception as e:
print('caught')
print_exc(e)
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