[3.11] gh-93382: Cache result of PyCode_GetCode in codeobject (GH-93383)

Include/cpython/code.h

@@ -89,6 +89,7 @@ typedef uint16_t _Py_CODEUNIT;
     PyObject *co_qualname;        /* unicode (qualname, for reference) */      \
     PyObject *co_linetable;       /* bytes object that holds location info */  \
     PyObject *co_weakreflist;     /* to support weakrefs to code objects */    \
+    PyObject *_co_code;           /* cached co_code object/attribute */        \
     char *_co_linearray;          /* array of line offsets */                  \
     /* Scratch space for extra data relating to the code object.               \
        Type is a void* to keep the format private in codeobject.c to force     \

Misc/NEWS.d/next/Core and Builtins/2022-05-31-16-36-30.gh-issue-93382.Jf6gAj.rst

@@ -0,0 +1,2 @@
+Cache the result of :c:func:`PyCode_GetCode` function to restore the O(1)
+lookup of the :attr:`~types.CodeType.co_code` attribute.

Objects/codeobject.c

@@ -334,6 +334,7 @@ init_code(PyCodeObject *co, struct _PyCodeConstructor *con)
     /* not set */
     co->co_weakreflist = NULL;
     co->co_extra = NULL;
+    co->_co_code = NULL;
 
     co->co_warmup = QUICKENING_INITIAL_WARMUP_VALUE;
     co->_co_linearray_entry_size = 0;
@@ -1421,12 +1422,17 @@ deopt_code(_Py_CODEUNIT *instructions, Py_ssize_t len)
 PyObject *
 _PyCode_GetCode(PyCodeObject *co)
 {
+    if (co->_co_code != NULL) {
+        return Py_NewRef(co->_co_code);
+    }
     PyObject *code = PyBytes_FromStringAndSize((const char *)_PyCode_CODE(co),
                                                _PyCode_NBYTES(co));
     if (code == NULL) {
         return NULL;
     }
     deopt_code((_Py_CODEUNIT *)PyBytes_AS_STRING(code), Py_SIZE(co));
+    assert(co->_co_code == NULL);
+    co->_co_code = Py_NewRef(code);
     return code;
 }
 
@@ -1585,6 +1591,7 @@ code_dealloc(PyCodeObject *co)
     Py_XDECREF(co->co_qualname);
     Py_XDECREF(co->co_linetable);
     Py_XDECREF(co->co_exceptiontable);
+    Py_XDECREF(co->_co_code);
     if (co->co_weakreflist != NULL) {
         PyObject_ClearWeakRefs((PyObject*)co);
     }
@@ -2142,6 +2149,7 @@ _PyStaticCode_Dealloc(PyCodeObject *co)
     deopt_code(_PyCode_CODE(co), Py_SIZE(co));
     co->co_warmup = QUICKENING_INITIAL_WARMUP_VALUE;
     PyMem_Free(co->co_extra);
+    Py_CLEAR(co->_co_code);
     co->co_extra = NULL;
     if (co->co_weakreflist != NULL) {
         PyObject_ClearWeakRefs((PyObject *)co);

Tools/scripts/deepfreeze.py

@@ -279,6 +279,7 @@ def generate_code(self, name: str, code: types.CodeType) -> str:
             self.write(f".co_name = {co_name},")
             self.write(f".co_qualname = {co_qualname},")
             self.write(f".co_linetable = {co_linetable},")
+            self.write(f"._co_code = NULL,")
             self.write("._co_linearray = NULL,")
             self.write(f".co_code_adaptive = {co_code_adaptive},")
         name_as_code = f"(PyCodeObject *)&{name}"