mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-03 16:39:00 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8
cpython/Tools/cases_generator
History
Ken Jin cb640b659e
gh-128563: A new tail-calling interpreter (GH-128718) 
Co-authored-by: Garrett Gu <garrettgu777@gmail.com>
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
2025-02-06 23:21:57 +08:00
..
_typing_backports.py gh-104504: cases generator: Add --warn-unreachable to the mypy config (#108112) 2023-08-21 00:40:41 +01:00
analyzer.py gh-128563: A new tail-calling interpreter (GH-128718) 2025-02-06 23:21:57 +08:00
cwriter.py GH-119866: Spill the stack around escaping calls. (GH-124392) 2024-10-07 14:56:39 +01:00
generators_common.py gh-128563: A new tail-calling interpreter (GH-128718) 2025-02-06 23:21:57 +08:00
interpreter_definition.md gh-119786: Fix miscellaneous typos in InternalDocs/interpreter_definition.md (#127957) 2024-12-15 19:11:50 +02:00
lexer.py GH-128682: Spill the stack pointer in labels, as well as instructions (GH-129618) 2025-02-04 12:18:31 +00:00
mypy.ini Replace strict_concatenate = True with extra_checks = True (#126391) 2025-01-25 12:44:23 +03:00
opcode_id_generator.py GH-122390: Replace _Py_GetbaseOpcode with _Py_GetBaseCodeUnit (GH-122942) 2024-08-13 14:22:57 +01:00
opcode_metadata_generator.py Revert "GH-128914: Remove conditional stack effects from bytecodes.c and the code generators (GH-128918)" (GH-129202) 2025-01-23 09:26:25 +00:00
optimizer_generator.py GH-128682: Spill the stack pointer in labels, as well as instructions (GH-129618) 2025-02-04 12:18:31 +00:00
parser.py GH-128682: Spill the stack pointer in labels, as well as instructions (GH-129618) 2025-02-04 12:18:31 +00:00
parsing.py GH-128682: Spill the stack pointer in labels, as well as instructions (GH-129618) 2025-02-04 12:18:31 +00:00
plexer.py gh-106812: Refactor cases_generator to allow uops with array stack effects (#107564) 2023-08-04 09:35:56 -07:00
py_metadata_generator.py GH-120024: Tidy up case generator code a bit. (GH-122780) 2024-08-08 10:57:59 +01:00
README.md Rename tier 2 redundancy eliminator to optimizer (#115888) 2024-02-26 08:42:53 -08:00
stack.py GH-128682: Spill the stack pointer in labels, as well as instructions (GH-129618) 2025-02-04 12:18:31 +00:00
target_generator.py gh-128563: A new tail-calling interpreter (GH-128718) 2025-02-06 23:21:57 +08:00
tier1_generator.py gh-128563: A new tail-calling interpreter (GH-128718) 2025-02-06 23:21:57 +08:00
tier2_generator.py GH-128682: Spill the stack pointer in labels, as well as instructions (GH-129618) 2025-02-04 12:18:31 +00:00
uop_id_generator.py gh-120417: Remove unused imports in cases_generator (#120622) 2024-06-17 21:58:56 +02:00
uop_metadata_generator.py GH-126222: Fix _PyUop_num_popped (GH-126507) 2024-11-07 10:48:27 +00:00

README.md

Tooling to generate interpreters

Documentation for the instruction definitions in Python/bytecodes.c ("the DSL") is here.

What's currently here:

  • analyzer.py: code for converting AST generated by Parser to more high-level structure for easier interaction
  • lexer.py: lexer for C, originally written by Mark Shannon
  • plexer.py: OO interface on top of lexer.py; main class: PLexer
  • parsing.py: Parser for instruction definition DSL; main class: Parser
  • parser.py helper for interactions with parsing.py
  • tierN_generator.py: a couple of driver scripts to read Python/bytecodes.c and write Python/generated_cases.c.h (and several other files)
  • optimizer_generator.py: reads Python/bytecodes.c and Python/optimizer_bytecodes.c and writes Python/optimizer_cases.c.h
  • stack.py: code to handle generalized stack effects
  • cwriter.py: code which understands tokens and how to format C code; main class: CWriter
  • generators_common.py: helpers for generators
  • opcode_id_generator.py: generate a list of opcodes and write them to Include/opcode_ids.h
  • opcode_metadata_generator.py: reads the instruction definitions and write the metadata to Include/internal/pycore_opcode_metadata.h
  • py_metadata_generator.py: reads the instruction definitions and write the metadata to Lib/_opcode_metadata.py
  • target_generator.py: generate targets for computed goto dispatch and write them to Python/opcode_targets.h
  • uop_id_generator.py: generate a list of uop IDs and write them to Include/internal/pycore_uop_ids.h
  • uop_metadata_generator.py: reads the instruction definitions and write the metadata to Include/internal/pycore_uop_metadata.h

Note that there is some dummy C code at the top and bottom of Python/bytecodes.c to fool text editors like VS Code into believing this is valid C code.

A bit about the parser

The parser class uses a pretty standard recursive descent scheme, but with unlimited backtracking. The PLexer class tokenizes the entire input before parsing starts. We do not run the C preprocessor. Each parsing method returns either an AST node (a Node instance) or None, or raises SyntaxError (showing the error in the C source).

Most parsing methods are decorated with @contextual, which automatically resets the tokenizer input position when None is returned. Parsing methods may also raise SyntaxError, which is irrecoverable. When a parsing method returns None, it is possible that after backtracking a different parsing method returns a valid AST.

Neither the lexer nor the parsers are complete or fully correct. Most known issues are tersely indicated by # TODO: comments. We plan to fix issues as they become relevant.