bpo-43693: Revert commits 2c1e2583fdc4db6b43d163239ea42b0e8394171f and b2bf2bc1ece673d387341e06c8d3c2bc6e259747 (GH-26530)

* Revert "bpo-43693: Compute deref offsets in compiler (gh-25152)"

This reverts commit b2bf2bc1ece673d387341e06c8d3c2bc6e259747.

* Revert "bpo-43693: Add new internal code objects fields: co_fastlocalnames and co_fastlocalkinds. (gh-26388)"

This reverts commit 2c1e2583fdc4db6b43d163239ea42b0e8394171f.

These two commits are breaking the refleak buildbots.

1 files changed, 37 insertions, 122 deletions

diff --git a/Python/compile.c b/Python/compile.c
index 1104250..03d522b 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -2047,16 +2047,16 @@ static int
 compiler_make_closure(struct compiler *c, PyCodeObject *co, Py_ssize_t flags,
                       PyObject *qualname)
 {
+    Py_ssize_t i, free = PyCode_GetNumFree(co);
     if (qualname == NULL)
         qualname = co->co_name;
 
-    if (co->co_nfreevars) {
-        int i = co->co_nlocals + co->co_ncellvars;
-        for (; i < co->co_nlocalsplus; ++i) {
+    if (free) {
+        for (i = 0; i < free; ++i) {
             /* Bypass com_addop_varname because it will generate
                LOAD_DEREF but LOAD_CLOSURE is needed.
             */
-            PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
+            PyObject *name = PyTuple_GET_ITEM(co->co_freevars, i);
 
             /* Special case: If a class contains a method with a
                free variable that has the same name as a method,
@@ -2076,10 +2076,6 @@ compiler_make_closure(struct compiler *c, PyCodeObject *co, Py_ssize_t flags,
                 arg = compiler_lookup_arg(c->u->u_freevars, name);
             }
             if (arg == -1) {
-                PyObject *freevars = _PyCode_GetFreevars(co);
-                if (freevars == NULL) {
-                    PyErr_Clear();
-                }
                 PyErr_Format(PyExc_SystemError,
                     "compiler_lookup_arg(name=%R) with reftype=%d failed in %S; "
                     "freevars of code %S: %R",
@@ -2087,13 +2083,13 @@ compiler_make_closure(struct compiler *c, PyCodeObject *co, Py_ssize_t flags,
                     reftype,
                     c->u->u_name,
                     co->co_name,
-                    freevars);
+                    co->co_freevars);
                 return 0;
             }
             ADDOP_I(c, LOAD_CLOSURE, arg);
         }
         flags |= 0x08;
-        ADDOP_I(c, BUILD_TUPLE, co->co_nfreevars);
+        ADDOP_I(c, BUILD_TUPLE, free);
     }
     ADDOP_LOAD_CONST(c, (PyObject*)co);
     ADDOP_LOAD_CONST(c, qualname);
@@ -7180,46 +7176,6 @@ merge_const_one(struct compiler *c, PyObject **obj)
     return 1;
 }
 
-// This is in codeobject.c.
-extern void _Py_set_localsplus_info(int, PyObject *, _PyLocalsPlusKind,
-                                   PyObject *, _PyLocalsPlusKinds);
-
-static void
-compute_localsplus_info(struct compiler *c,
-                        PyObject *names, _PyLocalsPlusKinds kinds)
-{
-    int nlocalsplus = (int)PyTuple_GET_SIZE(names);
-
-    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.
-        _Py_set_localsplus_info(offset, k, CO_FAST_LOCAL, names, kinds);
-    }
-    int nlocals = (int)PyDict_GET_SIZE(c->u->u_varnames);
-
-    pos = 0;
-    while (PyDict_Next(c->u->u_cellvars, &pos, &k, &v)) {
-        int offset = (int)PyLong_AS_LONG(v);
-        assert(offset >= 0);
-        offset += nlocals;
-        assert(offset < nlocalsplus);
-        _Py_set_localsplus_info(offset, k, CO_FAST_CELL, names, kinds);
-    }
-
-    pos = 0;
-    while (PyDict_Next(c->u->u_freevars, &pos, &k, &v)) {
-        int offset = (int)PyLong_AS_LONG(v);
-        assert(offset >= 0);
-        offset += nlocals;
-        assert(offset < nlocalsplus);
-        _Py_set_localsplus_info(offset, k, CO_FAST_FREE, names, kinds);
-    }
-}
-
 static PyCodeObject *
 makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
          int maxdepth)
@@ -7227,23 +7183,37 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
     PyCodeObject *co = NULL;
     PyObject *names = NULL;
     PyObject *consts = NULL;
-    PyObject *localsplusnames = NULL;
-    _PyLocalsPlusKinds localspluskinds = NULL;
+    PyObject *varnames = NULL;
     PyObject *name = NULL;
+    PyObject *freevars = NULL;
+    PyObject *cellvars = NULL;
+    int flags;
+    int posorkeywordargcount, posonlyargcount, kwonlyargcount;
 
     names = dict_keys_inorder(c->u->u_names, 0);
-    if (!names) {
+    varnames = dict_keys_inorder(c->u->u_varnames, 0);
+    if (!names || !varnames) {
         goto error;
     }
-    if (!merge_const_one(c, &names)) {
+    cellvars = dict_keys_inorder(c->u->u_cellvars, 0);
+    if (!cellvars)
+        goto error;
+    freevars = dict_keys_inorder(c->u->u_freevars, PyTuple_GET_SIZE(cellvars));
+    if (!freevars)
         goto error;
-    }
 
-    int flags = compute_code_flags(c);
-    if (flags < 0) {
+    if (!merge_const_one(c, &names) ||
+            !merge_const_one(c, &varnames) ||
+            !merge_const_one(c, &cellvars) ||
+            !merge_const_one(c, &freevars))
+    {
         goto error;
     }
 
+    flags = compute_code_flags(c);
+    if (flags < 0)
+        goto error;
+
     consts = PyList_AsTuple(constslist); /* PyCode_New requires a tuple */
     if (consts == NULL) {
         goto error;
@@ -7252,32 +7222,9 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
         goto error;
     }
 
-    assert(c->u->u_posonlyargcount < INT_MAX);
-    assert(c->u->u_argcount < INT_MAX);
-    assert(c->u->u_kwonlyargcount < INT_MAX);
-    int posonlyargcount = (int)c->u->u_posonlyargcount;
-    int posorkwargcount = (int)c->u->u_argcount;
-    assert(INT_MAX - posonlyargcount - posorkwargcount > 0);
-    int kwonlyargcount = (int)c->u->u_kwonlyargcount;
-
-    Py_ssize_t nlocals = PyDict_GET_SIZE(c->u->u_varnames);
-    Py_ssize_t ncellvars = PyDict_GET_SIZE(c->u->u_cellvars);
-    Py_ssize_t nfreevars = PyDict_GET_SIZE(c->u->u_freevars);
-    assert(nlocals < INT_MAX);
-    assert(ncellvars < INT_MAX);
-    assert(nfreevars < INT_MAX);
-    assert(INT_MAX - nlocals - ncellvars - nfreevars > 0);
-    int nlocalsplus = (int)nlocals + (int)ncellvars + (int)nfreevars;
-
-    localsplusnames = PyTuple_New(nlocalsplus);
-    if (localsplusnames == NULL) {
-        goto error;
-    }
-    if (_PyCode_InitLocalsPlusKinds(nlocalsplus, &localspluskinds) < 0) {
-        goto error;
-    }
-    compute_localsplus_info(c, localsplusnames, localspluskinds);
-
+    posonlyargcount = Py_SAFE_DOWNCAST(c->u->u_posonlyargcount, Py_ssize_t, int);
+    posorkeywordargcount = Py_SAFE_DOWNCAST(c->u->u_argcount, Py_ssize_t, int);
+    kwonlyargcount = Py_SAFE_DOWNCAST(c->u->u_kwonlyargcount, Py_ssize_t, int);
     struct _PyCodeConstructor con = {
         .filename = c->c_filename,
         .name = c->u->u_name,
@@ -7290,10 +7237,11 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
         .consts = consts,
         .names = names,
 
-        .localsplusnames = localsplusnames,
-        .localspluskinds = localspluskinds,
+        .varnames = varnames,
+        .cellvars = cellvars,
+        .freevars = freevars,
 
-        .argcount = posonlyargcount + posorkwargcount,
+        .argcount = posonlyargcount + posorkeywordargcount,
         .posonlyargcount = posonlyargcount,
         .kwonlyargcount = kwonlyargcount,
 
@@ -7301,30 +7249,18 @@ makecode(struct compiler *c, struct assembler *a, PyObject *constslist,
 
         .exceptiontable = a->a_except_table,
     };
-
     if (_PyCode_Validate(&con) < 0) {
         goto error;
     }
-
-    if (!merge_const_one(c, &localsplusnames)) {
-        _PyCode_ClearLocalsPlusKinds(con.localspluskinds);
-        goto error;
-    }
-    con.localsplusnames = localsplusnames;
-
     co = _PyCode_New(&con);
-    if (co == NULL) {
-        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(varnames);
     Py_XDECREF(name);
+    Py_XDECREF(freevars);
+    Py_XDECREF(cellvars);
     return co;
 }
 
@@ -7435,24 +7371,6 @@ guarantee_lineno_for_exits(struct assembler *a, int firstlineno) {
     }
 }
 
-static void
-offset_derefs(basicblock *entryblock, int nlocals)
-{
-    for (basicblock *b = entryblock; b != NULL; b = b->b_next) {
-        for (int i = 0; i < b->b_iused; i++) {
-            struct instr *inst = &b->b_instr[i];
-            switch(inst->i_opcode) {
-                case LOAD_CLOSURE:
-                case LOAD_DEREF:
-                case STORE_DEREF:
-                case DELETE_DEREF:
-                case LOAD_CLASSDEREF:
-                    inst->i_oparg += nlocals;
-            }
-        }
-    }
-}
-
 static PyCodeObject *
 assemble(struct compiler *c, int addNone)
 {
@@ -7508,9 +7426,6 @@ assemble(struct compiler *c, int addNone)
     a.a_entry = entryblock;
     a.a_nblocks = nblocks;
 
-    assert(PyDict_GET_SIZE(c->u->u_varnames) < INT_MAX);
-    offset_derefs(entryblock, (int)PyDict_GET_SIZE(c->u->u_varnames));
-
     consts = consts_dict_keys_inorder(c->u->u_consts);
     if (consts == NULL) {
         goto error;