bpo-43693: Turn localspluskinds into an object

Include/cpython/code.h

@@ -26,9 +26,6 @@ typedef uint16_t _Py_CODEUNIT;
 typedef struct _PyOpcache _PyOpcache;
 
 
-typedef unsigned char _PyLocalsPlusKind;
-typedef _PyLocalsPlusKind *_PyLocalsPlusKinds;
-
 /* Bytecode object */
 struct PyCodeObject{
  PyObject_HEAD
@@ -75,7 +72,7 @@ struct PyCodeObject{
  int co_firstlineno; /* first source line number */
  PyObject *co_code; /* instruction opcodes */
  PyObject *co_localsplusnames; /* tuple mapping offsets to names */
-_PyLocalsPlusKinds co_localspluskinds; /* array mapping to local kinds */
+PyObject *co_localspluskinds; /* Bytes mapping to local kinds (one byte per variable) */
  PyObject *co_filename; /* unicode (where it was loaded from) */
  PyObject *co_name; /* unicode (name, for reference) */
  PyObject *co_linetable; /* string (encoding addr<->lineno mapping) See
@@ -222,4 +219,3 @@ void PyLineTable_InitAddressRange(const char *linetable, Py_ssize_t length, int
 int PyLineTable_NextAddressRange(PyCodeAddressRange *range);
 int PyLineTable_PreviousAddressRange(PyCodeAddressRange *range);
 
-

Include/internal/pycore_code.h

@@ -180,39 +180,34 @@ extern Py_ssize_t _Py_QuickenedCount;
  * "free" kind is mutually exclusive with both.
  */
 
-// For now _PyLocalsPlusKind and _PyLocalsPlusKinds are defined
-// in Include/cpython/code.h.
-/* Note that these all fit within _PyLocalsPlusKind, as do combinations. */
+// Note that these all fit within a byte, as do combinations.
 // Later, we will use the smaller numbers to differentiate the different
 // kinds of locals (e.g. pos-only arg, varkwargs, local-only).
 #define CO_FAST_LOCAL 0x20
 #define CO_FAST_CELL 0x40
 #define CO_FAST_FREE 0x80
 
-static inline int
-_PyCode_InitLocalsPlusKinds(int num, _PyLocalsPlusKinds *pkinds)
+typedef unsigned char _PyLocals_Kind;
+
+static inline _PyLocals_Kind
+_PyLocals_GetKind(PyObject *kinds, int i)
 {
- if (num == 0){
- *pkinds = NULL;
- return 0;
- }
- _PyLocalsPlusKinds kinds = PyMem_NEW(_PyLocalsPlusKind, num);
- if (kinds == NULL){
- PyErr_NoMemory();
- return -1;
- }
- *pkinds = kinds;
- return 0;
+ assert(PyBytes_Check(kinds));
+ assert(0 <= i && i < PyBytes_GET_SIZE(kinds));
+ char *ptr = PyBytes_AS_STRING(kinds);
+ return (_PyLocals_Kind)(ptr[i]);
 }
 
 static inline void
-_PyCode_ClearLocalsPlusKinds(_PyLocalsPlusKinds kinds)
+_PyLocals_SetKind(PyObject *kinds, int i, _PyLocals_Kind kind)
 {
- if (kinds != NULL){
- PyMem_Free(kinds);
- }
+ assert(PyBytes_Check(kinds));
+ assert(0 <= i && i < PyBytes_GET_SIZE(kinds));
+ char *ptr = PyBytes_AS_STRING(kinds);
+ ptr[i] = (char) kind;
 }
 
+
 struct _PyCodeConstructor{
  /* metadata */
  PyObject *filename;
@@ -229,8 +224,8 @@ struct _PyCodeConstructor{
  PyObject *names;
 
  /* mapping frame offsets to information */
- PyObject *localsplusnames;
-_PyLocalsPlusKinds localspluskinds;
+ PyObject *localsplusnames; // Tuple of strings
+PyObject *localspluskinds; // Bytes object, one byte per variable
 
  /* args (within varnames) */
  int argcount;

Lib/ctypes/test/test_values.py

@@ -80,9 +80,9 @@ class struct_frozen(Structure):
  continue
  items.append((entry.name.decode("ascii"), entry.size))
 
- expected = [("__hello__", 128),
- ("__phello__", -128),
- ("__phello__.spam", 128),
+ expected = [("__hello__", 133),
+ ("__phello__", -133),
+ ("__phello__.spam", 133),
  ]
  self.assertEqual(items, expected, "PyImport_FrozenModules example "
  "in Doc/library/ctypes.rst may be out of date")

Lib/importlib/_bootstrap_external.py

@@ -359,6 +359,7 @@ def _write_atomic(path, data, mode=0o666):
 # Python 3.11a1 3454 (compute cell offsets relative to locals bpo-43693)
 # Python 3.11a1 3455 (add MAKE_CELL bpo-43693)
 # Python 3.11a1 3456 (interleave cell args bpo-43693)
+# Python 3.11a1 3457 (Change localsplus to a bytes object bpo-43693)
 
 #
 # MAGIC must change whenever the bytecode emitted by the compiler may no
@@ -368,7 +369,7 @@ def _write_atomic(path, data, mode=0o666):
 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
 # in PC/launcher.c must also be updated.
 
-MAGIC_NUMBER = (3456).to_bytes(2, 'little') + b'\r\n'
+MAGIC_NUMBER = (3457).to_bytes(2, 'little') + b'\r\n'
 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c
 
 _PYCACHE = '__pycache__'

Objects/codeobject.c

@@ -156,16 +156,16 @@ validate_and_copy_tuple(PyObject *tup)
 
 // This is also used in compile.c.
 void
-_Py_set_localsplus_info(int offset, PyObject *name, _PyLocalsPlusKind kind,
- PyObject *names, _PyLocalsPlusKinds kinds)
+_Py_set_localsplus_info(int offset, PyObject *name, _PyLocals_Kind kind,
+PyObject *names, PyObject *kinds)
 {
  Py_INCREF(name);
  PyTuple_SET_ITEM(names, offset, name);
- kinds[offset] = kind;
+_PyLocals_SetKind(kinds, offset, kind);
 }
 
 static void
-get_localsplus_counts(PyObject *names, _PyLocalsPlusKinds kinds,
+get_localsplus_counts(PyObject *names, PyObject *kinds,
  int *pnlocals, int *pnplaincellvars, int *pncellvars,
  int *pnfreevars)
 {
@@ -175,17 +175,18 @@ get_localsplus_counts(PyObject *names, _PyLocalsPlusKinds kinds,
  int nfreevars = 0;
  Py_ssize_t nlocalsplus = PyTuple_GET_SIZE(names);
  for (int i = 0; i < nlocalsplus; i++){
- if (kinds[i] & CO_FAST_LOCAL){
+ _PyLocals_Kind kind = _PyLocals_GetKind(kinds, i);
+ if (kind & CO_FAST_LOCAL){
  nlocals += 1;
- if (kinds[i] & CO_FAST_CELL){
+ if (kind & CO_FAST_CELL){
  ncellvars += 1;
  }
  }
- else if (kinds[i] & CO_FAST_CELL){
+ else if (kind & CO_FAST_CELL){
  ncellvars += 1;
  nplaincellvars += 1;
  }
- else if (kinds[i] & CO_FAST_FREE){
+ else if (kind & CO_FAST_FREE){
  nfreevars += 1;
  }
  }
@@ -204,15 +205,16 @@ get_localsplus_counts(PyObject *names, _PyLocalsPlusKinds kinds,
 }
 
 static PyObject *
-get_localsplus_names(PyCodeObject *co, _PyLocalsPlusKind kind, int num)
+get_localsplus_names(PyCodeObject *co, _PyLocals_Kind kind, int num)
 {
  PyObject *names = PyTuple_New(num);
  if (names == NULL){
  return NULL;
  }
  int index = 0;
  for (int offset = 0; offset < co->co_nlocalsplus; offset++){
- if ((co->co_localspluskinds[offset] & kind) == 0){
+ _PyLocals_Kind k = _PyLocals_GetKind(co->co_localspluskinds, offset);
+ if ((k & kind) == 0){
  continue;
  }
  assert(index < num);
@@ -236,8 +238,9 @@ _PyCode_Validate(struct _PyCodeConstructor *con)
  con->consts == NULL || !PyTuple_Check(con->consts) ||
  con->names == NULL || !PyTuple_Check(con->names) ||
  con->localsplusnames == NULL || !PyTuple_Check(con->localsplusnames) ||
- (PyTuple_GET_SIZE(con->localsplusnames) && con->localspluskinds == NULL) ||
- (!PyTuple_GET_SIZE(con->localsplusnames) && con->localspluskinds != NULL) ||
+ con->localspluskinds == NULL || !PyBytes_Check(con->localspluskinds) ||
+ PyTuple_GET_SIZE(con->localsplusnames)
+ != PyBytes_GET_SIZE(con->localspluskinds) ||
  con->name == NULL || !PyUnicode_Check(con->name) ||
  con->filename == NULL || !PyUnicode_Check(con->filename) ||
  con->linetable == NULL || !PyBytes_Check(con->linetable) ||
@@ -309,7 +312,7 @@ init_code(PyCodeObject *co, struct _PyCodeConstructor *con)
 
  Py_INCREF(con->localsplusnames);
  co->co_localsplusnames = con->localsplusnames;
-// We take ownership of the kinds array.
+Py_INCREF(con->localspluskinds);
  co->co_localspluskinds = con->localspluskinds;
 
  co->co_argcount = con->argcount;
@@ -394,7 +397,7 @@ PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount,
 {
  PyCodeObject *co = NULL;
  PyObject *localsplusnames = NULL;
-_PyLocalsPlusKinds localspluskinds = NULL;
+PyObject *localspluskinds = NULL;
 
  if (varnames == NULL || !PyTuple_Check(varnames) ||
  cellvars == NULL || !PyTuple_Check(cellvars) ||
@@ -413,7 +416,8 @@ PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount,
  if (localsplusnames == NULL){
  goto error;
  }
- if (_PyCode_InitLocalsPlusKinds(nlocalsplus, &localspluskinds) < 0){
+ localspluskinds = PyBytes_FromStringAndSize(NULL, nlocalsplus);
+ if (localspluskinds == NULL){
  goto error;
  }
  int offset = 0;
@@ -438,7 +442,8 @@ PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount,
  // Merge the localsplus indices.
  nlocalsplus -= 1;
  offset -= 1;
- localspluskinds[argoffset] |= CO_FAST_CELL;
+ _PyLocals_Kind kind = _PyLocals_GetKind(localspluskinds, argoffset);
+ _PyLocals_SetKind(localspluskinds, argoffset, kind | CO_FAST_CELL);
  continue;
  }
  _Py_set_localsplus_info(offset, name, CO_FAST_CELL,
@@ -495,7 +500,6 @@ PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount,
  goto error;
  }
 
- localspluskinds = NULL; // This keeps it from getting freed below.
  Py_INCREF(varnames);
  co->co_varnames = varnames;
  Py_INCREF(cellvars);
@@ -505,7 +509,7 @@ PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount,
 
 error:
  Py_XDECREF(localsplusnames);
-_PyCode_ClearLocalsPlusKinds(localspluskinds);
+Py_XDECREF(localspluskinds);
  return co;
 }
 
@@ -558,6 +562,7 @@ PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno)
  .consts = nulltuple,
  .names = nulltuple,
  .localsplusnames = nulltuple,
+ .localspluskinds = emptystring,
  .exceptiontable = emptystring,
  };
  result = _PyCode_New(&con);
@@ -1142,7 +1147,7 @@ code_dealloc(PyCodeObject *co)
  Py_XDECREF(co->co_consts);
  Py_XDECREF(co->co_names);
  Py_XDECREF(co->co_localsplusnames);
-_PyCode_ClearLocalsPlusKinds(co->co_localspluskinds);
+Py_XDECREF(co->co_localspluskinds);
  Py_XDECREF(co->co_varnames);
  Py_XDECREF(co->co_freevars);
  Py_XDECREF(co->co_cellvars);

Objects/frameobject.c

@@ -958,7 +958,7 @@ PyFrame_FastToLocalsWithError(PyFrameObject *f)
  co = _PyFrame_GetCode(f);
  fast = f->f_localsptr;
  for (int i = 0; i < co->co_nlocalsplus; i++){
-_PyLocalsPlusKind kind = co->co_localspluskinds[i];
+_PyLocals_Kind kind = _PyLocals_GetKind(co->co_localspluskinds, i);
 
  /* If the namespace is unoptimized, then one of the
  following cases applies:
@@ -1052,7 +1052,7 @@ PyFrame_LocalsToFast(PyFrameObject *f, int clear)
 
  PyErr_Fetch(&error_type, &error_value, &error_traceback);
  for (int i = 0; i < co->co_nlocalsplus; i++){
-_PyLocalsPlusKind kind = co->co_localspluskinds[i];
+_PyLocals_Kind kind = _PyLocals_GetKind(co->co_localspluskinds, i);
 
  /* Same test as in PyFrame_FastToLocals() above. */
  if (kind & CO_FAST_FREE && !(co->co_flags & CO_OPTIMIZED)){

Objects/typeobject.c

@@ -8864,7 +8864,7 @@ super_init_without_args(PyFrameObject *f, PyCodeObject *co,
 
  PyObject *firstarg = f->f_localsptr[0];
  // The first argument might be a cell.
- if (firstarg != NULL && (co->co_localspluskinds[0] & CO_FAST_CELL)){
+ if (firstarg != NULL && (_PyLocals_GetKind(co->co_localspluskinds, 0) & CO_FAST_CELL)){
  // "firstarg" is a cell here unless (very unlikely) super()
  // was called from the C-API before the first MAKE_CELL op.
  if (f->f_lasti >= 0){
@@ -8883,7 +8883,7 @@ super_init_without_args(PyFrameObject *f, PyCodeObject *co,
  PyTypeObject *type = NULL;
  int i = co->co_nlocals + co->co_nplaincellvars;
  for (; i < co->co_nlocalsplus; i++){
- assert((co->co_localspluskinds[i] & CO_FAST_FREE) != 0);
+ assert((_PyLocals_GetKind(co->co_localspluskinds, i) & CO_FAST_FREE) != 0);
  PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
  assert(PyUnicode_Check(name));
  if (_PyUnicode_EqualToASCIIId(name, &PyId___class__)){

Python/compile.c

@@ -7187,23 +7187,21 @@ merge_const_one(struct compiler *c, PyObject **obj)
 }
 
 // This is in codeobject.c.
-extern void _Py_set_localsplus_info(int, PyObject *, _PyLocalsPlusKind,
- PyObject *, _PyLocalsPlusKinds);
+extern void _Py_set_localsplus_info(int, PyObject *, unsigned char,
+ PyObject *, PyObject *);
 
 static void
 compute_localsplus_info(struct compiler *c, int nlocalsplus,
- PyObject *names, _PyLocalsPlusKinds kinds)
+ PyObject *names, PyObject *kinds)
 {
- assert(PyTuple_GET_SIZE(names) == nlocalsplus);
-
  PyObject *k, *v;
  Py_ssize_t pos = 0;
  while (PyDict_Next(c->u->u_varnames, &pos, &k, &v)){
  int offset = (int)PyLong_AS_LONG(v);
  assert(offset >= 0);
  assert(offset < nlocalsplus);
  // For now we do not distinguish arg kinds.
-_PyLocalsPlusKind kind = CO_FAST_LOCAL;
+_PyLocals_Kind kind = CO_FAST_LOCAL;
  if (PyDict_GetItem(c->u->u_cellvars, k) != NULL){
  kind |= CO_FAST_CELL;
  }
@@ -7245,7 +7243,7 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
  PyObject *names = NULL;
  PyObject *consts = NULL;
  PyObject *localsplusnames = NULL;
-_PyLocalsPlusKinds localspluskinds = NULL;
+PyObject *localspluskinds = NULL;
  PyObject *name = NULL;
 
  names = dict_keys_inorder(c->u->u_names, 0);
@@ -7281,7 +7279,8 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
  if (localsplusnames == NULL){
  goto error;
  }
- if (_PyCode_InitLocalsPlusKinds(nlocalsplus, &localspluskinds) < 0){
+ localspluskinds = PyBytes_FromStringAndSize(NULL, nlocalsplus);
+ if (localspluskinds == NULL){
  goto error;
  }
  compute_localsplus_info(c, nlocalsplus, localsplusnames, localspluskinds);
@@ -7315,7 +7314,6 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
  }
 
  if (!merge_const_one(c, &localsplusnames)){
- _PyCode_ClearLocalsPlusKinds(con.localspluskinds);
  goto error;
  }
  con.localsplusnames = localsplusnames;
@@ -7325,13 +7323,11 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
  goto error;
  }
 
- localspluskinds = NULL; // This keeps it from getting freed below.
-
  error:
  Py_XDECREF(names);
  Py_XDECREF(consts);
  Py_XDECREF(localsplusnames);
-_PyCode_ClearLocalsPlusKinds(localspluskinds);
+Py_XDECREF(localspluskinds);
  Py_XDECREF(name);
  return co;
 }

Python/frozen_hello.h

@@ -5,7 +5,8 @@ const unsigned char _Py_M__hello[] ={
  100,1,131,1,1,0,100,2,83,0,41,3,84,122,12,72,
  101,108,108,111,32,119,111,114,108,100,33,78,41,2,90,11,
  105,110,105,116,105,97,108,105,122,101,100,218,5,112,114,105,
- 110,116,169,0,122,14,60,102,114,111,122,101,110,32,104,101,
- 108,108,111,62,218,8,60,109,111,100,117,108,101,62,1,0,
- 0,0,115,4,0,0,0,4,0,12,1,243,0,0,0,0,
+ 110,116,169,0,243,0,0,0,0,122,14,60,102,114,111,122,
+ 101,110,32,104,101,108,108,111,62,218,8,60,109,111,100,117,
+ 108,101,62,1,0,0,0,115,4,0,0,0,4,0,12,1,
+ 114,2,0,0,0,
 };