cpython/Tools/cases_generator/flags.py

102 lines
3.3 KiB
Python

import dataclasses
from formatting import Formatter
import lexer as lx
import parsing
@dataclasses.dataclass
class InstructionFlags:
"""Construct and manipulate instruction flags"""
HAS_ARG_FLAG: bool
HAS_CONST_FLAG: bool
HAS_NAME_FLAG: bool
HAS_JUMP_FLAG: bool
HAS_FREE_FLAG: bool
HAS_LOCAL_FLAG: bool
def __post_init__(self) -> None:
self.bitmask = {name: (1 << i) for i, name in enumerate(self.names())}
@staticmethod
def fromInstruction(instr: parsing.Node) -> "InstructionFlags":
has_free = (
variable_used(instr, "PyCell_New")
or variable_used(instr, "PyCell_GET")
or variable_used(instr, "PyCell_SET")
)
return InstructionFlags(
HAS_ARG_FLAG=variable_used(instr, "oparg"),
HAS_CONST_FLAG=variable_used(instr, "FRAME_CO_CONSTS"),
HAS_NAME_FLAG=variable_used(instr, "FRAME_CO_NAMES"),
HAS_JUMP_FLAG=variable_used(instr, "JUMPBY"),
HAS_FREE_FLAG=has_free,
HAS_LOCAL_FLAG=(
variable_used(instr, "GETLOCAL") or variable_used(instr, "SETLOCAL")
)
and not has_free,
)
@staticmethod
def newEmpty() -> "InstructionFlags":
return InstructionFlags(False, False, False, False, False, False)
def add(self, other: "InstructionFlags") -> None:
for name, value in dataclasses.asdict(other).items():
if value:
setattr(self, name, value)
def names(self, value: bool | None = None) -> list[str]:
if value is None:
return list(dataclasses.asdict(self).keys())
return [n for n, v in dataclasses.asdict(self).items() if v == value]
def bitmap(self) -> int:
flags = 0
for name in self.names():
if getattr(self, name):
flags |= self.bitmask[name]
return flags
@classmethod
def emit_macros(cls, out: Formatter) -> None:
flags = cls.newEmpty()
for name, value in flags.bitmask.items():
out.emit(f"#define {name} ({value})")
for name, value in flags.bitmask.items():
out.emit(
f"#define OPCODE_{name[:-len('_FLAG')]}(OP) "
f"(_PyOpcode_opcode_metadata[OP].flags & ({name}))"
)
def variable_used(node: parsing.Node, name: str) -> bool:
"""Determine whether a variable with a given name is used in a node."""
return any(
token.kind == "IDENTIFIER" and token.text == name for token in node.tokens
)
def variable_used_unspecialized(node: parsing.Node, name: str) -> bool:
"""Like variable_used(), but skips #if ENABLE_SPECIALIZATION blocks."""
tokens: list[lx.Token] = []
skipping = False
for i, token in enumerate(node.tokens):
if token.kind == "MACRO":
text = "".join(token.text.split())
# TODO: Handle nested #if
if text == "#if":
if i + 1 < len(node.tokens) and node.tokens[i + 1].text in (
"ENABLE_SPECIALIZATION",
"TIER_ONE",
):
skipping = True
elif text in ("#else", "#endif"):
skipping = False
if not skipping:
tokens.append(token)
return any(token.kind == "IDENTIFIER" and token.text == name for token in tokens)