| .. | ||
| _typing_backports.py | ||
| analyzer.py | ||
| cwriter.py | ||
| generators_common.py | ||
| interpreter_definition.md | ||
| lexer.py | ||
| mypy.ini | ||
| opcode_id_generator.py | ||
| opcode_metadata_generator.py | ||
| optimizer_generator.py | ||
| parser.py | ||
| parsing.py | ||
| plexer.py | ||
| py_metadata_generator.py | ||
| README.md | ||
| stack.py | ||
| target_generator.py | ||
| tier1_generator.py | ||
| tier2_generator.py | ||
| uop_id_generator.py | ||
| uop_metadata_generator.py | ||
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 convertingASTgenerated byParserto more high-level structure for easier interactionlexer.py: lexer for C, originally written by Mark Shannonplexer.py: OO interface on top of lexer.py; main class:PLexerparsing.py: Parser for instruction definition DSL; main class:Parserparser.pyhelper for interactions withparsing.pytierN_generator.py: a couple of driver scripts to readPython/bytecodes.cand writePython/generated_cases.c.h(and several other files)optimizer_generator.py: readsPython/bytecodes.candPython/optimizer_bytecodes.cand writesPython/optimizer_cases.c.hstack.py: code to handle generalized stack effectscwriter.py: code which understands tokens and how to format C code; main class:CWritergenerators_common.py: helpers for generatorsopcode_id_generator.py: generate a list of opcodes and write them toInclude/opcode_ids.hopcode_metadata_generator.py: reads the instruction definitions and write the metadata toInclude/internal/pycore_opcode_metadata.hpy_metadata_generator.py: reads the instruction definitions and write the metadata toLib/_opcode_metadata.pytarget_generator.py: generate targets for computed goto dispatch and write them toPython/opcode_targets.huop_id_generator.py: generate a list of uop IDs and write them toInclude/internal/pycore_uop_ids.huop_metadata_generator.py: reads the instruction definitions and write the metadata toInclude/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.