GH-106008: Make implicit boolean conversions explicit

.gitattributes

@@ -86,6 +86,7 @@ Parser/token.c                                      generated
 Programs/test_frozenmain.h                          generated
 Python/Python-ast.c                                 generated
 Python/generated_cases.c.h                          generated
+Python/opcode_metadata.h                            generated
 Python/opcode_targets.h                             generated
 Python/stdlib_module_names.h                        generated
 Tools/peg_generator/pegen/grammar_parser.py         generated

Doc/library/dis.rst

@@ -43,12 +43,12 @@
       adaptive bytecode can be shown by passing ``adaptive=True``.
 
 
 Example: Given the function :func:`myfunc`::
 
    def myfunc(alist):
        return len(alist)
 
 the following command can be used to display the disassembly of
 :func:`myfunc`:
 
 .. doctest::
@@ -529,6 +529,9 @@
 
    Implements ``STACK[-1] = not STACK[-1]``.
 
+   .. versionchanged:: 3.13
+      This instruction now requires an exact :class:`bool` operand.
+
 
 .. opcode:: UNARY_INVERT
 
@@ -548,6 +551,13 @@
    .. versionadded:: 3.5
 
 
+.. opcode:: TO_BOOL
+
+   Implements ``STACK[-1] = bool(STACK[-1])``.
+
+   .. versionadded:: 3.13
+
+
 **Binary and in-place operations**
 
 Binary operations remove the top two items from the stack (``STACK[-1]`` and
@@ -841,7 +851,7 @@
 
 .. opcode:: LOAD_BUILD_CLASS
 
    Pushes :func:`builtins.__build_class__` onto the stack.  It is later called
    to construct a class.
 
 
@@ -898,14 +908,14 @@
 
 .. opcode:: STORE_NAME (namei)
 
    Implements ``name = STACK.pop()``. *namei* is the index of *name* in the attribute
    :attr:`co_names` of the code object. The compiler tries to use
    :opcode:`STORE_FAST` or :opcode:`STORE_GLOBAL` if possible.
 
 
 .. opcode:: DELETE_NAME (namei)
 
    Implements ``del name``, where *namei* is the index into :attr:`co_names`
    attribute of the code object.
 
 
@@ -944,7 +954,7 @@
       value = STACK.pop()
       obj.name = value
 
    where *namei* is the index of name in :attr:`co_names`.
 
 .. opcode:: DELETE_ATTR (namei)
 
@@ -953,7 +963,7 @@
       obj = STACK.pop()
       del obj.name
 
    where *namei* is the index of name into :attr:`co_names`.
 
 
 .. opcode:: STORE_GLOBAL (namei)
@@ -1127,7 +1137,12 @@
 .. opcode:: COMPARE_OP (opname)
 
    Performs a Boolean operation.  The operation name can be found in
-   ``cmp_op[opname]``.
+   ``cmp_op[opname >> 5]``. If the fifth-lowest bit of ``opname`` is set
+   (``opname & 16``), the result should be coerced to ``bool``.
+
+   .. versionchanged:: 3.13
+      The fifth-lowest bit of the oparg now indicates a forced conversion to
+      :class:`bool`.
 
 
 .. opcode:: IS_OP (invert)
@@ -1191,6 +1206,9 @@
    .. versionchanged:: 3.12
       This is no longer a pseudo-instruction.
 
+   .. versionchanged:: 3.13
+      This instruction now requires an exact :class:`bool` operand.
+
 .. opcode:: POP_JUMP_IF_FALSE (delta)
 
    If ``STACK[-1]`` is false, increments the bytecode counter by *delta*.
@@ -1204,6 +1222,9 @@
    .. versionchanged:: 3.12
       This is no longer a pseudo-instruction.
 
+   .. versionchanged:: 3.13
+      This instruction now requires an exact :class:`bool` operand.
+
 .. opcode:: POP_JUMP_IF_NOT_NONE (delta)
 
    If ``STACK[-1]`` is not ``None``, increments the bytecode counter by *delta*.

Include/internal/pycore_code.h

@@ -101,6 +101,13 @@ typedef struct {
 
 #define INLINE_CACHE_ENTRIES_SEND CACHE_ENTRIES(_PySendCache)
 
+typedef struct {
+    uint16_t counter;
+    uint16_t version[2];
+} _PyToBoolCache;
+
+#define INLINE_CACHE_ENTRIES_TO_BOOL CACHE_ENTRIES(_PyToBoolCache)
+
 // Borrowed references to common callables:
 struct callable_cache {
     PyObject *isinstance;
@@ -246,6 +253,7 @@ extern void _Py_Specialize_UnpackSequence(PyObject *seq, _Py_CODEUNIT *instr,
                                           int oparg);
 extern void _Py_Specialize_ForIter(PyObject *iter, _Py_CODEUNIT *instr, int oparg);
 extern void _Py_Specialize_Send(PyObject *receiver, _Py_CODEUNIT *instr);
+extern void _Py_Specialize_ToBool(PyObject *value, _Py_CODEUNIT *instr);
 
 /* Finalizer function for static codeobjects used in deepfreeze.py */
 extern void _PyStaticCode_Fini(PyCodeObject *co);