[tarantool-patches] Re: [PATCH v9 4/7] lua: remove exceptions from function luaL_tofield()
Mergen Imeev
imeevma at tarantool.org
Fri Mar 29 00:41:27 MSK 2019
Added check for number of returned values after pcall. Diff below.
On Thu, Mar 28, 2019 at 10:56:32PM +0300, Mergen Imeev wrote:
> Thank you for fixes! I checked and added some more fixes:
> 1) I added new field is_value_returned for struct
> lua_serialize_status.
> 2) I changed all "return 0" to "return 1" because we should return
> exactly one result since we call this function through pcall.
> 3) I pushed a new value on stack when serialization is not used.
> I think it should work even without this value, since we will
> discard it, but I’m not 100% sure of that.
>
> Diff between commits and diff of whole patch below. I haven't
> squashed these two review fixes.
>
> On Thu, Mar 28, 2019 at 09:40:00PM +0300, Vladislav Shpilevoy wrote:
> > Thanks for the fixes! I've pushed my review fixes on the
> > branch, and dropped at the end of the email. But I've not
> > tested them, so I propose you to do that, if you agree
> > with the concept.
> >
> > =========================================================
> >
Diff:
diff --git a/src/lua/utils.c b/src/lua/utils.c
index e3b12d8..1612c5a 100644
--- a/src/lua/utils.c
+++ b/src/lua/utils.c
@@ -440,10 +440,8 @@ lua_field_try_serialize(struct lua_State *L)
s->is_serialize_used = (luaL_getmetafield(L, 1, LUAL_SERIALIZE) != 0);
s->is_error = false;
s->is_value_returned = false;
- if (! s->is_serialize_used) {
- lua_pushvalue(L, 1);
- return 1;
- }
+ if (! s->is_serialize_used)
+ return 0;
struct luaL_serializer *cfg = s->cfg;
struct luaL_field *field = s->field;
if (lua_isfunction(L, -1)) {
@@ -457,7 +455,8 @@ lua_field_try_serialize(struct lua_State *L)
if (!lua_isstring(L, -1)) {
diag_set(LuajitError, "invalid " LUAL_SERIALIZE " value");
s->is_error = true;
- return 1;
+ lua_pop(L, 1);
+ return 0;
}
const char *type = lua_tostring(L, -1);
if (strcmp(type, "array") == 0 || strcmp(type, "seq") == 0 ||
@@ -477,7 +476,8 @@ lua_field_try_serialize(struct lua_State *L)
diag_set(LuajitError, "invalid " LUAL_SERIALIZE " value");
s->is_error = true;
}
- return 1;
+ lua_pop(L, 1);
+ return 0;
}
static int
@@ -489,6 +489,7 @@ lua_field_inspect_table(struct lua_State *L, struct luaL_serializer *cfg,
uint32_t max = 0;
if (cfg->encode_load_metatables) {
+ int top = lua_gettop(L);
struct lua_serialize_status s;
s.cfg = cfg;
s.field = field;
@@ -501,6 +502,8 @@ lua_field_inspect_table(struct lua_State *L, struct luaL_serializer *cfg,
}
if (s.is_error)
return -1;
+ assert(lua_gettop(L) == top + 1);
+ (void)top;
if (s.is_serialize_used && s.is_value_returned)
lua_replace(L, idx);
else
New patch:
diff --git a/src/box/lua/call.c b/src/box/lua/call.c
index 52939ae..2049ee5 100644
--- a/src/box/lua/call.c
+++ b/src/box/lua/call.c
@@ -164,7 +164,8 @@ luamp_encode_call_16(lua_State *L, struct luaL_serializer *cfg,
*/
for (int i = 1; i <= nrets; ++i) {
struct luaL_field field;
- luaL_tofield(L, cfg, i, &field);
+ if (luaL_tofield(L, cfg, i, &field) < 0)
+ return luaT_error(L);
struct tuple *tuple;
if (field.type == MP_EXT &&
(tuple = luaT_istuple(L, i)) != NULL) {
@@ -192,7 +193,8 @@ luamp_encode_call_16(lua_State *L, struct luaL_serializer *cfg,
* Inspect the first result
*/
struct luaL_field root;
- luaL_tofield(L, cfg, 1, &root);
+ if (luaL_tofield(L, cfg, 1, &root) < 0)
+ return luaT_error(L);
struct tuple *tuple;
if (root.type == MP_EXT && (tuple = luaT_istuple(L, 1)) != NULL) {
/* `return box.tuple()` */
@@ -221,7 +223,8 @@ luamp_encode_call_16(lua_State *L, struct luaL_serializer *cfg,
for (uint32_t t = 1; t <= root.size; t++) {
lua_rawgeti(L, 1, t);
struct luaL_field field;
- luaL_tofield(L, cfg, -1, &field);
+ if (luaL_tofield(L, cfg, -1, &field) < 0)
+ return luaT_error(L);
if (field.type == MP_EXT && (tuple = luaT_istuple(L, -1))) {
tuple_to_mpstream(tuple, stream);
} else if (field.type != MP_ARRAY) {
diff --git a/src/box/lua/tuple.c b/src/box/lua/tuple.c
index 60c1a39..1903ee8 100644
--- a/src/box/lua/tuple.c
+++ b/src/box/lua/tuple.c
@@ -229,7 +229,8 @@ luamp_convert_key(struct lua_State *L, struct luaL_serializer *cfg,
return tuple_to_mpstream(tuple, stream);
struct luaL_field field;
- luaL_tofield(L, cfg, index, &field);
+ if (luaL_tofield(L, cfg, index, &field) < 0)
+ luaT_error(L);
if (field.type == MP_ARRAY) {
lua_pushvalue(L, index);
luamp_encode_r(L, cfg, stream, &field, 0);
diff --git a/src/lua/msgpack.c b/src/lua/msgpack.c
index b470060..1b1874e 100644
--- a/src/lua/msgpack.c
+++ b/src/lua/msgpack.c
@@ -149,10 +149,12 @@ restart: /* used by MP_EXT */
lua_pushnil(L); /* first key */
while (lua_next(L, top) != 0) {
lua_pushvalue(L, -2); /* push a copy of key to top */
- luaL_tofield(L, cfg, lua_gettop(L), field);
+ if (luaL_tofield(L, cfg, lua_gettop(L), field) < 0)
+ return luaT_error(L);
luamp_encode_r(L, cfg, stream, field, level + 1);
lua_pop(L, 1); /* pop a copy of key */
- luaL_tofield(L, cfg, lua_gettop(L), field);
+ if (luaL_tofield(L, cfg, lua_gettop(L), field) < 0)
+ return luaT_error(L);
luamp_encode_r(L, cfg, stream, field, level + 1);
lua_pop(L, 1); /* pop value */
}
@@ -168,7 +170,8 @@ restart: /* used by MP_EXT */
mpstream_encode_array(stream, size);
for (uint32_t i = 0; i < size; i++) {
lua_rawgeti(L, top, i + 1);
- luaL_tofield(L, cfg, top + 1, field);
+ if (luaL_tofield(L, cfg, top + 1, field) < 0)
+ return luaT_error(L);
luamp_encode_r(L, cfg, stream, field, level + 1);
lua_pop(L, 1);
}
@@ -203,7 +206,8 @@ luamp_encode(struct lua_State *L, struct luaL_serializer *cfg,
}
struct luaL_field field;
- luaL_tofield(L, cfg, lua_gettop(L), &field);
+ if (luaL_tofield(L, cfg, lua_gettop(L), &field) < 0)
+ return luaT_error(L);
enum mp_type top_type = luamp_encode_r(L, cfg, stream, &field, 0);
if (!on_top) {
diff --git a/src/lua/utils.c b/src/lua/utils.c
index a418b95..1612c5a 100644
--- a/src/lua/utils.c
+++ b/src/lua/utils.c
@@ -392,61 +392,126 @@ lua_field_inspect_ucdata(struct lua_State *L, struct luaL_serializer *cfg,
lua_pcall(L, 1, 1, 0);
/* replace obj with the unpacked value */
lua_replace(L, idx);
- luaL_tofield(L, cfg, idx, field);
+ if (luaL_tofield(L, cfg, idx, field) < 0)
+ luaT_error(L);
} /* else ignore lua_gettable exceptions */
lua_settop(L, top); /* remove temporary objects */
}
-static void
-lua_field_inspect_table(struct lua_State *L, struct luaL_serializer *cfg,
- int idx, struct luaL_field *field)
-{
- assert(lua_type(L, idx) == LUA_TTABLE);
- const char *type;
- uint32_t size = 0;
- uint32_t max = 0;
-
- /* Try to get field LUAL_SERIALIZER_TYPE from metatable */
- if (!cfg->encode_load_metatables ||
- !luaL_getmetafield(L, idx, LUAL_SERIALIZE))
- goto skip;
+/**
+ * A helper structure to simplify safe call of __serialize method.
+ * It passes some arguments into the serializer called via pcall,
+ * and carries out some results.
+ */
+struct lua_serialize_status {
+ /**
+ * True if an attempt to call __serialize has failed. A
+ * diag message is set.
+ */
+ bool is_error;
+ /**
+ * True, if __serialize exists. Otherwise an ordinary
+ * default serialization is used.
+ */
+ bool is_serialize_used;
+ /**
+ * True, if value should be returned after serialization.
+ */
+ bool is_value_returned;
+ /** Parameters, passed originally to luaL_tofield. */
+ struct luaL_serializer *cfg;
+ struct luaL_field *field;
+};
+/**
+ * Call __serialize method of a table object if the former exists.
+ * The function expects 2 values pushed onto the Lua stack: a
+ * value to serialize, and a pointer at a struct
+ * lua_serialize_status object. If __serialize exists and is
+ * correct, then one value is pushed as a result of serialization.
+ * Otherwise is_error and is_serialize_used attributes of status
+ * should be checked.
+ */
+static int
+lua_field_try_serialize(struct lua_State *L)
+{
+ struct lua_serialize_status *s =
+ (struct lua_serialize_status *) lua_touserdata(L, 2);
+ s->is_serialize_used = (luaL_getmetafield(L, 1, LUAL_SERIALIZE) != 0);
+ s->is_error = false;
+ s->is_value_returned = false;
+ if (! s->is_serialize_used)
+ return 0;
+ struct luaL_serializer *cfg = s->cfg;
+ struct luaL_field *field = s->field;
if (lua_isfunction(L, -1)) {
/* copy object itself */
- lua_pushvalue(L, idx);
+ lua_pushvalue(L, 1);
lua_call(L, 1, 1);
- /* replace obj with the unpacked value */
- lua_replace(L, idx);
- luaL_tofield(L, cfg, idx, field);
- return;
- } else if (!lua_isstring(L, -1)) {
- luaL_error(L, "invalid " LUAL_SERIALIZE " value");
+ s->is_error = (luaL_tofield(L, cfg, -1, field) != 0);
+ s->is_value_returned = true;
+ return 1;
}
-
- type = lua_tostring(L, -1);
+ if (!lua_isstring(L, -1)) {
+ diag_set(LuajitError, "invalid " LUAL_SERIALIZE " value");
+ s->is_error = true;
+ lua_pop(L, 1);
+ return 0;
+ }
+ const char *type = lua_tostring(L, -1);
if (strcmp(type, "array") == 0 || strcmp(type, "seq") == 0 ||
strcmp(type, "sequence") == 0) {
field->type = MP_ARRAY; /* Override type */
- field->size = luaL_arrlen(L, idx);
+ field->size = luaL_arrlen(L, 1);
/* YAML: use flow mode if __serialize == 'seq' */
if (cfg->has_compact && type[3] == '\0')
field->compact = true;
- lua_pop(L, 1); /* type */
-
- return;
} else if (strcmp(type, "map") == 0 || strcmp(type, "mapping") == 0) {
field->type = MP_MAP; /* Override type */
- field->size = luaL_maplen(L, idx);
+ field->size = luaL_maplen(L, 1);
/* YAML: use flow mode if __serialize == 'map' */
if (cfg->has_compact && type[3] == '\0')
field->compact = true;
- lua_pop(L, 1); /* type */
- return;
} else {
- luaL_error(L, "invalid " LUAL_SERIALIZE " value");
+ diag_set(LuajitError, "invalid " LUAL_SERIALIZE " value");
+ s->is_error = true;
+ }
+ lua_pop(L, 1);
+ return 0;
+}
+
+static int
+lua_field_inspect_table(struct lua_State *L, struct luaL_serializer *cfg,
+ int idx, struct luaL_field *field)
+{
+ assert(lua_type(L, idx) == LUA_TTABLE);
+ uint32_t size = 0;
+ uint32_t max = 0;
+
+ if (cfg->encode_load_metatables) {
+ int top = lua_gettop(L);
+ struct lua_serialize_status s;
+ s.cfg = cfg;
+ s.field = field;
+ lua_pushcfunction(L, lua_field_try_serialize);
+ lua_pushvalue(L, idx);
+ lua_pushlightuserdata(L, &s);
+ if (lua_pcall(L, 2, 1, 0) != 0) {
+ diag_set(LuajitError, lua_tostring(L, -1));
+ return -1;
+ }
+ if (s.is_error)
+ return -1;
+ assert(lua_gettop(L) == top + 1);
+ (void)top;
+ if (s.is_serialize_used && s.is_value_returned)
+ lua_replace(L, idx);
+ else
+ lua_pop(L, 1);
+ if (s.is_serialize_used)
+ return 0;
}
-skip:
field->type = MP_ARRAY;
/* Calculate size and check that table can represent an array */
@@ -465,7 +530,7 @@ skip:
}
field->type = MP_MAP;
field->size = size;
- return;
+ return 0;
}
if (k > max)
max = k;
@@ -475,15 +540,18 @@ skip:
if (cfg->encode_sparse_ratio > 0 &&
max > size * (uint32_t)cfg->encode_sparse_ratio &&
max > (uint32_t)cfg->encode_sparse_safe) {
- if (!cfg->encode_sparse_convert)
- luaL_error(L, "excessively sparse array");
+ if (!cfg->encode_sparse_convert) {
+ diag_set(LuajitError, "excessively sparse array");
+ return -1;
+ }
field->type = MP_MAP;
field->size = size;
- return;
+ return 0;
}
assert(field->type == MP_ARRAY);
field->size = max;
+ return 0;
}
static void
@@ -496,12 +564,13 @@ lua_field_tostring(struct lua_State *L, struct luaL_serializer *cfg, int idx,
lua_call(L, 1, 1);
lua_replace(L, idx);
lua_settop(L, top);
- luaL_tofield(L, cfg, idx, field);
+ if (luaL_tofield(L, cfg, idx, field) < 0)
+ luaT_error(L);
}
-void
+int
luaL_tofield(struct lua_State *L, struct luaL_serializer *cfg, int index,
- struct luaL_field *field)
+ struct luaL_field *field)
{
if (index < 0)
index = lua_gettop(L) + index + 1;
@@ -510,10 +579,12 @@ luaL_tofield(struct lua_State *L, struct luaL_serializer *cfg, int index,
double intpart;
size_t size;
-#define CHECK_NUMBER(x) ({\
- if (!isfinite(x) && !cfg->encode_invalid_numbers) { \
- if (!cfg->encode_invalid_as_nil) \
- luaL_error(L, "number must not be NaN or Inf"); \
+#define CHECK_NUMBER(x) ({ \
+ if (!isfinite(x) && !cfg->encode_invalid_numbers) { \
+ if (!cfg->encode_invalid_as_nil) { \
+ diag_set(LuajitError, "number must not be NaN or Inf"); \
+ return -1; \
+ } \
field->type = MP_NIL; \
}})
@@ -534,94 +605,93 @@ luaL_tofield(struct lua_State *L, struct luaL_serializer *cfg, int index,
field->dval = num;
CHECK_NUMBER(num);
}
- return;
+ return 0;
case LUA_TCDATA:
{
- uint32_t ctypeid = 0;
- void *cdata = luaL_checkcdata(L, index, &ctypeid);
+ GCcdata *cd = cdataV(L->base + index - 1);
+ void *cdata = (void *)cdataptr(cd);
+
int64_t ival;
- switch (ctypeid) {
+ switch (cd->ctypeid) {
case CTID_BOOL:
field->type = MP_BOOL;
field->bval = *(bool*) cdata;
- return;
+ return 0;
case CTID_CCHAR:
case CTID_INT8:
ival = *(int8_t *) cdata;
field->type = (ival >= 0) ? MP_UINT : MP_INT;
field->ival = ival;
- return;
+ return 0;
case CTID_INT16:
ival = *(int16_t *) cdata;
field->type = (ival >= 0) ? MP_UINT : MP_INT;
field->ival = ival;
- return;
+ return 0;
case CTID_INT32:
ival = *(int32_t *) cdata;
field->type = (ival >= 0) ? MP_UINT : MP_INT;
field->ival = ival;
- return;
+ return 0;
case CTID_INT64:
ival = *(int64_t *) cdata;
field->type = (ival >= 0) ? MP_UINT : MP_INT;
field->ival = ival;
- return;
+ return 0;
case CTID_UINT8:
field->type = MP_UINT;
field->ival = *(uint8_t *) cdata;
- return;
+ return 0;
case CTID_UINT16:
field->type = MP_UINT;
field->ival = *(uint16_t *) cdata;
- return;
+ return 0;
case CTID_UINT32:
field->type = MP_UINT;
field->ival = *(uint32_t *) cdata;
- return;
+ return 0;
case CTID_UINT64:
field->type = MP_UINT;
field->ival = *(uint64_t *) cdata;
- return;
+ return 0;
case CTID_FLOAT:
field->type = MP_FLOAT;
field->fval = *(float *) cdata;
CHECK_NUMBER(field->fval);
- return;
+ return 0;
case CTID_DOUBLE:
field->type = MP_DOUBLE;
field->dval = *(double *) cdata;
CHECK_NUMBER(field->dval);
- return;
+ return 0;
case CTID_P_CVOID:
case CTID_P_VOID:
if (*(void **) cdata == NULL) {
field->type = MP_NIL;
- return;
+ return 0;
}
/* Fall through */
default:
field->type = MP_EXT;
- return;
}
- return;
+ return 0;
}
case LUA_TBOOLEAN:
field->type = MP_BOOL;
field->bval = lua_toboolean(L, index);
- return;
+ return 0;
case LUA_TNIL:
field->type = MP_NIL;
- return;
+ return 0;
case LUA_TSTRING:
field->sval.data = lua_tolstring(L, index, &size);
field->sval.len = (uint32_t) size;
field->type = MP_STR;
- return;
+ return 0;
case LUA_TTABLE:
{
field->compact = false;
- lua_field_inspect_table(L, cfg, index, field);
- return;
+ return lua_field_inspect_table(L, cfg, index, field);
}
case LUA_TLIGHTUSERDATA:
case LUA_TUSERDATA:
@@ -629,14 +699,14 @@ luaL_tofield(struct lua_State *L, struct luaL_serializer *cfg, int index,
field->sval.len = 0;
if (lua_touserdata(L, index) == NULL) {
field->type = MP_NIL;
- return;
+ return 0;
}
/* Fall through */
default:
field->type = MP_EXT;
- return;
}
#undef CHECK_NUMBER
+ return 0;
}
void
diff --git a/src/lua/utils.h b/src/lua/utils.h
index 96311b7..df4d50e 100644
--- a/src/lua/utils.h
+++ b/src/lua/utils.h
@@ -311,8 +311,11 @@ struct luaL_field {
* @param cfg configuration
* @param index stack index
* @param field conversion result
+ *
+ * @retval 0 Success.
+ * @retval -1 Error.
*/
-void
+int
luaL_tofield(struct lua_State *L, struct luaL_serializer *cfg, int index,
struct luaL_field *field);
@@ -352,7 +355,8 @@ static inline void
luaL_checkfield(struct lua_State *L, struct luaL_serializer *cfg, int idx,
struct luaL_field *field)
{
- luaL_tofield(L, cfg, idx, field);
+ if (luaL_tofield(L, cfg, idx, field) < 0)
+ luaT_error(L);
if (field->type != MP_EXT)
return;
luaL_convertfield(L, cfg, idx, field);
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