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.
diff --git a/py/objexcept.c b/py/objexcept.c
index 824c9b0..8bd802e 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -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 @@
// 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 @@
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 @@
// 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 @@
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 @@
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.
- 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.
- return;
- }
- }
- #endif
+ // append this traceback info to traceback data
+ // if memory allocation fails (eg because gc is locked), just return
- // 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) {
+ if (self->traceback_data == NULL) {
+ self->traceback_data = m_new_maybe(mp_uint_t, 3);
+ if (self->traceback_data == NULL) {
return;
}
+ 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;
}
- 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;
}
}
diff --git a/py/objexcept.h b/py/objexcept.h
index d6cfacd..783f694 100644
--- a/py/objexcept.h
+++ b/py/objexcept.h
@@ -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;
diff --git a/py/objlist.c b/py/objlist.c
index e9af365..e0c8953 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -477,25 +477,6 @@
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;
diff --git a/py/objlist.h b/py/objlist.h
index 1f3f452..443ede5 100644
--- a/py/objlist.h
+++ b/py/objlist.h
@@ -35,6 +35,4 @@
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__
diff --git a/tests/misc/print_exception.py b/tests/misc/print_exception.py
index e65b8d1..4e23bf1 100644
--- a/tests/misc/print_exception.py
+++ b/tests/misc/print_exception.py
@@ -6,19 +6,35 @@
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)