The-OpenROAD-Project_OpenROAD-flow-scripts/flow/scripts/memories/schema.py

#!/usr/bin/env python3
"""The `.memories` file format: a JSON inventory of memory macros.

One `.memories` file (and the flow-generated `memories.json`) describes
memories at the module boundary: geometry, the full pin list with each
pin's function, the behavioral model the RTL provides, and whether the
memory is converted to a macro (`idiomatic`).

The file-based handoff is deliberate: everything downstream — synthesis
blackboxing, liberty/LEF consumption in later stages, build systems that
declare flow artifacts as transitive dependencies — keys off these files
rather than off in-process state.
"""

from __future__ import annotations

import json
from dataclasses import asdict, dataclass, field
from pathlib import Path

SCHEMA_VERSION = 1

PIN_FUNCTIONS = ("addr", "en", "wmode", "mask", "data_in", "data_out", "clk")
DIRECTIONS = ("input", "output")


class SchemaError(ValueError):
    pass


@dataclass
class Pin:
    name: str
    direction: str  # "input" / "output"
    width: int
    port_id: str  # "R0", "W1", "RW0", ...
    function: str  # one of PIN_FUNCTIONS


@dataclass
class Memory:
    name: str
    rows: int = 0
    bits: int = 0
    addr_w: int = 0
    read_ports: int = 0
    write_ports: int = 0
    rw_ports: int = 0
    # Total width of the per-port write mask, 0 if unmasked. Subword-split
    # mask pins (`W0_mask_0..3`) contribute one lane each.
    mask_lanes: int = 0
    pins: list[Pin] = field(default_factory=list)
    # The module whose RTL body simulates this memory: {"file", "module"}.
    behavioral_model: dict | None = None
    # True when the memory is converted to a macro (.lib/.lef emitted and
    # the module blackboxed); False leaves it to synthesize as flops.
    idiomatic: bool = False
    reason: str = ""

    def total_ports(self) -> int:
        return self.read_ports + self.write_ports + self.rw_ports

    def to_dict(self) -> dict:
        return asdict(self)


def _pin_from_dict(d: dict) -> Pin:
    if not isinstance(d, dict):
        raise SchemaError("expected a dictionary for pin record")
    try:
        pin = Pin(
            name=d["name"],
            direction=d["direction"],
            width=int(d["width"]),
            port_id=d["port_id"],
            function=d["function"],
        )
    except KeyError as e:
        raise SchemaError(f"pin record missing field {e}") from e
    if pin.direction not in DIRECTIONS:
        raise SchemaError(f"pin {pin.name}: bad direction '{pin.direction}'")
    if pin.function not in PIN_FUNCTIONS:
        raise SchemaError(
            f"pin {pin.name}: unknown function "
            f"'{pin.function}' (expected one of "
            f"{', '.join(PIN_FUNCTIONS)})"
        )
    if pin.width < 1:
        raise SchemaError(f"pin {pin.name}: width must be >= 1")
    if not pin.port_id:
        raise SchemaError(f"pin {pin.name}: empty port_id")
    return pin


def memory_from_dict(d: dict) -> Memory:
    if not isinstance(d, dict):
        raise SchemaError("expected a dictionary for memory record")
    if "name" not in d:
        raise SchemaError("memory record missing 'name'")
    mem = Memory(name=d["name"])
    for key in (
        "rows",
        "bits",
        "addr_w",
        "read_ports",
        "write_ports",
        "rw_ports",
        "mask_lanes",
    ):
        if key in d:
            setattr(mem, key, int(d[key]))
    if "pins" in d:
        mem.pins = [_pin_from_dict(p) for p in d["pins"]]
    if "behavioral_model" in d:
        mem.behavioral_model = d["behavioral_model"]
    if "idiomatic" in d:
        mem.idiomatic = bool(d["idiomatic"])
    if "reason" in d:
        mem.reason = str(d["reason"])
    return mem


def load(path: Path) -> list[Memory]:
    """Load a .memories / memories.json file.

    We expect the JSON file to be valid and readable. If it is not,
    uncaught exceptions (e.g. FileNotFoundError, JSONDecodeError) provide
    full detailed stack traces and debug information.
    """
    doc = json.loads(path.read_text())
    if not isinstance(doc, dict) or "memories" not in doc:
        raise SchemaError(f"{path}: expected an object with a 'memories' list")
    version = doc.get("version", SCHEMA_VERSION)
    if version != SCHEMA_VERSION:
        raise SchemaError(f"{path}: unsupported schema version {version}")
    return [memory_from_dict(m) for m in doc["memories"]]


def dump(memories: list[Memory], path: Path, platform: str) -> None:
    doc = {
        "version": SCHEMA_VERSION,
        "platform": platform,
        "memories": [m.to_dict() for m in sorted(memories, key=lambda m: m.name)],
    }
    path.write_text(json.dumps(doc, indent=2) + "\n")


def merge(detected: list[Memory], overrides: list[Memory]) -> list[Memory]:
    """Merge user-supplied entries onto the detected set.

    An override naming a detected memory replaces only the fields it
    carries (geometry and pins are kept from detection unless the
    override provides its own). An override naming an unknown memory is
    taken whole — it must then carry pins and geometry itself to be
    emittable.
    """
    by_name = {m.name: m for m in detected}
    for o in overrides:
        base = by_name.get(o.name)
        if base is None:
            by_name[o.name] = o
            continue
        if o.pins:
            base.pins = o.pins
        for key in (
            "rows",
            "bits",
            "addr_w",
            "read_ports",
            "write_ports",
            "rw_ports",
            "mask_lanes",
        ):
            value = getattr(o, key)
            if value:
                setattr(base, key, value)
        if o.behavioral_model is not None:
            base.behavioral_model = o.behavioral_model
        if o.idiomatic:
            base.idiomatic = True
        if o.reason:
            base.reason = o.reason
    return list(by_name.values())


def validate_emittable(mem: Memory) -> None:
    """Raise SchemaError unless `mem` carries enough to emit .lib/.lef."""
    if not mem.pins:
        raise SchemaError(f"memory {mem.name}: no pins")
    if mem.rows < 1 or mem.bits < 1:
        raise SchemaError(
            f"memory {mem.name}: rows ({mem.rows}) and bits ({mem.bits}) "
            f"must be >= 1"
        )
    port_ids = {p.port_id for p in mem.pins}
    for port_id in port_ids:
        functions = {p.function for p in mem.pins if p.port_id == port_id}
        if "clk" not in functions:
            raise SchemaError(f"memory {mem.name}: port {port_id} has no clk pin")
        if "addr" not in functions:
            raise SchemaError(f"memory {mem.name}: port {port_id} has no addr pin")
        if not functions & {"data_in", "data_out"}:
            raise SchemaError(f"memory {mem.name}: port {port_id} has no data pin")