The switch cases (really TARGET(opcode) macros) have been moved from ceval.c to generated_cases.c.h. That file is generated from instruction definitions in bytecodes.c (which impersonates a C file so the C code it contains can be edited without custom support in e.g. VS Code).

The code generator lives in Tools/cases_generator (it has a README.md explaining how it works). The DSL used to describe the instructions is a work in progress, described in https://github.com/faster-cpython/ideas/blob/main/3.12/interpreter_definition.md.

This is surely a work-in-progress. An easy next step could be auto-generating super-instructions.

**IMPORTANT: Merge Conflicts**

If you get a merge conflict for instruction implementations in ceval.c, your best bet is to port your changes to bytecodes.c. That file looks almost the same as the original cases, except instead of `TARGET(NAME)` it uses `inst(NAME)`, and the trailing `DISPATCH()` call is omitted (the code generator adds it automatically).

Debt I owe from PR GH-98830.

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

…rnings. (#99093)

Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>

)

Also mark those opcodes that have no stack effect as such.

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

python#99271)

Also mark those opcodes that have no stack effect as such.

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

python#99271)

Also mark those opcodes that have no stack effect as such.

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

Also complete cache effects for BINARY_SUBSCR family.

Newly supported interpreter definition syntax:
- `op(NAME, (input_stack_effects -- output_stack_effects)) { ... }`
- `macro(NAME) = OP1 + OP2;`

Also some other random improvements:
- Convert `WITH_EXCEPT_START` to use stack effects
- Fix lexer to balk at unrecognized characters, e.g. `@`
- Fix moved output names; support object pointers in cache
- Introduce `error()` method to print errors
- Introduce read_uint16(p) as equivalent to `*p`

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

)

Stack effects can now have a type, e.g. `inst(X, (left, right -- jump/uint64_t)) { ... }`.

Instructions converted to the non-legacy format:

* COMPARE_OP
* COMPARE_OP_FLOAT_JUMP
* COMPARE_OP_INT_JUMP
* COMPARE_OP_STR_JUMP
* STORE_ATTR
* DELETE_ATTR
* STORE_GLOBAL
* STORE_ATTR_INSTANCE_VALUE
* STORE_ATTR_WITH_HINT
* STORE_ATTR_SLOT, and complete the store_attr family
* Complete the store_subscr family: STORE_SUBSCR{,DICT,LIST_INT}
  (STORE_SUBSCR was alread half converted,
  but wasn't using cache effects yet.)
* DELETE_SUBSCR
* PRINT_EXPR
* INTERPRETER_EXIT (a bit weird, ends in return)
* RETURN_VALUE
* GET_AITER (had to restructure it some)
  The original had mysterious `SET_TOP(NULL)` before `goto error`.
  I assume those just account for `obj` having been decref'ed,
  so I got rid of them in favor of the cleanup implied by `ERROR_IF()`.
* LIST_APPEND (a bit unhappy with it)
* SET_ADD (also a bit unhappy with it)

Various other improvements/refactorings as well.

This makes it easier to see what changed in the generated code
when converting an instruction to super or macro.

…#100205)

The presence of this macro indicates that a particular instruction
may be considered for conversion to a register-based format
(see faster-cpython/ideas#485).

An invariant (currently unchecked) is that `DEOPT_IF()` may only
occur *before* `DECREF_INPUTS()`, and `ERROR_IF()` may only occur
*after* it. One reason not to check this is that there are a few
places where we insert *two* `DECREF_INPUTS()` calls, in different
branches of the code. The invariant checking would have to be able
to do some flow control analysis to understand this.

Note that many instructions, especially specialized ones,
can't be converted to use this macro straightforwardly.
This is because the generator currently only generates plain
`Py_DECREF(variable)` statements, and cannot generate
things like `_Py_DECREF_SPECIALIZED()` let alone deal with
`_PyList_AppendTakeRef()`.

… input (python#100205)

The presence of this macro indicates that a particular instruction
may be considered for conversion to a register-based format
(see faster-cpython/ideas#485).

An invariant (currently unchecked) is that `DEOPT_IF()` may only
occur *before* `DECREF_INPUTS()`, and `ERROR_IF()` may only occur
*after* it. One reason not to check this is that there are a few
places where we insert *two* `DECREF_INPUTS()` calls, in different
branches of the code. The invariant checking would have to be able
to do some flow control analysis to understand this.

Note that many instructions, especially specialized ones,
can't be converted to use this macro straightforwardly.
This is because the generator currently only generates plain
`Py_DECREF(variable)` statements, and cannot generate
things like `_Py_DECREF_SPECIALIZED()` let alone deal with
`_PyList_AppendTakeRef()`.

* origin/main: (1306 commits)
  Correct CVE-2020-10735 documentation (python#100306)
  pythongh-100272: Fix JSON serialization of OrderedDict (pythonGH-100273)
  pythongh-93649: Split tracemalloc tests from _testcapimodule.c (python#99551)
  Docs: Use `PY_VERSION_HEX` for version comparison (python#100179)
  pythongh-97909: Fix markup for `PyMethodDef` members (python#100089)
  pythongh-99240: Reset pointer to NULL when the pointed memory is freed in argument parsing (python#99890)
  pythongh-99240: Reset pointer to NULL when the pointed memory is freed in argument parsing (python#99890)
  pythonGH-98831: Add DECREF_INPUTS(), expanding to DECREF() each stack input (python#100205)
  pythongh-78707: deprecate passing >1 argument to `PurePath.[is_]relative_to()` (pythonGH-94469)
  pythongh-99540: Constant hash for _PyNone_Type to aid reproducibility (pythonGH-99541)
  pythongh-100039: enhance __signature__ to work with str and callables (pythonGH-100168)
  pythongh-99830: asyncio: Document returns of remove_{reader,writer} (python#100302)
  "Compound statement" docs: Fix with-statement step indexing (python#100286)
  pythonGH-90043: Handle NaNs in COMPARE_OP_FLOAT_JUMP (pythonGH-100278)
  Improve stats presentation for calls. (pythonGH-100274)
  Better stats for `LOAD_ATTR` and `STORE_ATTR` (pythonGH-100295)
  pythongh-81057: Move the Cached Parser Dummy Name to _PyRuntimeState (python#100277)
  Document that zipfile's pwd parameter is a `bytes` object (python#100209)
  pythongh-99767: mark `PyTypeObject.tp_watched` as internal use only in table (python#100271)
  Fix typo in introduction.rst (python#100266)
  ...

* main:
  pythongh-89727: Fix os.walk RecursionError on deep trees (python#99803)
  Docs: Don't upload CI artifacts (python#100330)
  pythongh-94912: Added marker for non-standard coroutine function detection (python#99247)
  Correct CVE-2020-10735 documentation (python#100306)
  pythongh-100272: Fix JSON serialization of OrderedDict (pythonGH-100273)
  pythongh-93649: Split tracemalloc tests from _testcapimodule.c (python#99551)
  Docs: Use `PY_VERSION_HEX` for version comparison (python#100179)
  pythongh-97909: Fix markup for `PyMethodDef` members (python#100089)
  pythongh-99240: Reset pointer to NULL when the pointed memory is freed in argument parsing (python#99890)
  pythongh-99240: Reset pointer to NULL when the pointed memory is freed in argument parsing (python#99890)
  pythonGH-98831: Add DECREF_INPUTS(), expanding to DECREF() each stack input (python#100205)
  pythongh-78707: deprecate passing >1 argument to `PurePath.[is_]relative_to()` (pythonGH-94469)