commit c079c089981251599950d859101f33b39b7a7322
Author: Asherah Connor <ashe@kivikakk.ee>
Date:   Thu Jun 13 21:51:30 2024 +0300

    init.

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..583d76c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+__pycache__
+/build
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..3162d1d
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+Copyright (C) 2024 Asherah Connor
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..56866fa
--- /dev/null
+++ b/README.md
@@ -0,0 +1,9 @@
+# niar
+
+A small framework for building projects with [Amaranth].
+
+See the [template project] for usage.
+
+[Amaranth]: https://amaranth-lang.org/
+[template project]: https://github.com/kivikakk/niar-template
+
diff --git a/niar/__init__.py b/niar/__init__.py
new file mode 100644
index 0000000..b52fcf9
--- /dev/null
+++ b/niar/__init__.py
@@ -0,0 +1,26 @@
+from argparse import ArgumentParser
+
+from . import build, cxxrtl
+from .cxxrtl_platform import CxxrtlPlatform
+from .project import Project
+
+__all__ = ["Project", "cli", "CxxrtlPlatform"]
+
+
+def cli(np: Project):
+    parser = ArgumentParser(prog=np.name)
+    subparsers = parser.add_subparsers(required=True)
+
+    build.add_arguments(
+        np,
+        subparsers.add_parser(
+            "build", help="build the design, and optionally program it"
+        ),
+    )
+    if getattr(np, "cxxrtl_targets"):
+        cxxrtl.add_arguments(
+            np, subparsers.add_parser("cxxrtl", help="run the C++ simulator tests")
+        )
+
+    args = parser.parse_args()
+    args.func(args)
diff --git a/niar/build.py b/niar/build.py
new file mode 100644
index 0000000..e427be1
--- /dev/null
+++ b/niar/build.py
@@ -0,0 +1,108 @@
+import importlib
+import inspect
+import logging
+import re
+from functools import partial
+from typing import Optional
+
+from amaranth.build import Platform
+
+from .logger import logger, logtime
+from .project import Project
+
+__all__ = ["add_arguments"]
+
+
+def add_arguments(np: Project, parser):
+    parser.set_defaults(func=partial(main, np))
+    match sorted(t.__name__ for t in np.targets):
+        case []:
+            raise RuntimeError("no buildable targets defined")
+        case [first, *rest]:
+            parser.add_argument(
+                "-b",
+                "--board",
+                choices=[first, *rest],
+                help="which board to build for",
+                required=bool(rest),
+                **({"default": first} if not rest else {}),
+            )
+    parser.add_argument(
+        "-p",
+        "--program",
+        action="store_true",
+        help="program the design onto the board after building",
+    )
+    parser.add_argument(
+        "-v",
+        "--verilog",
+        action="store_true",
+        help="output debug Verilog",
+    )
+
+
+def main(np: Project, args):
+    logger.info("building %s for %s", np.name, args.board)
+
+    platform = np.target_by_name(args.board)
+    design = construct_top(np, platform)
+
+    with logtime(logging.DEBUG, "elaboration"):
+        plan = platform.prepare(
+            design,
+            np.name,
+            debug_verilog=args.verilog,
+            yosys_opts="-g",
+        )
+    fn = f"{np.name}.il"
+    size = len(plan.files[fn])
+    logger.debug(f"{fn!r}: {size:,} bytes")
+
+    with logtime(logging.DEBUG, "synthesis/pnr"):
+        products = plan.execute_local("build")
+
+    if args.program:
+        with logtime(logging.DEBUG, "programming"):
+            platform.toolchain_program(products, np.name)
+
+    heading = re.compile(r"^\d+\.\d+\. Printing statistics\.$", flags=re.MULTILINE)
+    next_heading = re.compile(r"^\d+\.\d+\. ", flags=re.MULTILINE)
+    log_file_between(logging.INFO, f"build/{np.name}.rpt", heading, next_heading)
+
+    logger.info("Device utilisation:")
+    heading = re.compile(r"^Info: Device utilisation:$", flags=re.MULTILINE)
+    next_heading = re.compile(r"^Info: Placed ", flags=re.MULTILINE)
+    log_file_between(
+        logging.INFO, f"build/{np.name}.tim", heading, next_heading, prefix="Info: "
+    )
+
+
+def construct_top(np: Project, platform: Platform, **kwargs):
+    sig = inspect.signature(np.top)
+    if "platform" in sig.parameters:
+        kwargs["platform"] = platform
+    return np.top(**kwargs)
+
+
+def log_file_between(
+    level: int,
+    path: str,
+    start: re.Pattern,
+    end: re.Pattern,
+    *,
+    prefix: Optional[str] = None,
+):
+    with open(path, "r") as f:
+        for line in f:
+            if start.match(line):
+                break
+        else:
+            return
+
+        for line in f:
+            if end.match(line):
+                return
+            line = line.rstrip()
+            if prefix is not None:
+                line = line.removeprefix(prefix)
+            logger.log(level, line)
diff --git a/niar/cxxrtl.py b/niar/cxxrtl.py
new file mode 100644
index 0000000..70dca4f
--- /dev/null
+++ b/niar/cxxrtl.py
@@ -0,0 +1,197 @@
+import json
+import logging
+import subprocess
+from enum import Enum
+from functools import partial
+from pathlib import Path
+from typing import Any
+
+from amaranth import Elaboratable
+from amaranth._toolchain.yosys import YosysBinary, find_yosys
+from amaranth.back import rtlil
+
+from .build import construct_top
+from .cxxrtl_platform import CxxrtlPlatform
+from .logger import logger, logtime
+from .project import Project
+
+__all__ = ["add_arguments"]
+
+CXXFLAGS = [
+    "-std=c++17",
+    "-g",
+    "-pedantic",
+    "-Wall",
+    "-Wextra",
+    "-Wno-zero-length-array",
+    "-Wno-unused-parameter",
+]
+
+
+class _Optimize(Enum):
+    none = "none"
+    rtl = "rtl"
+
+    def __str__(self):
+        return self.value
+
+    @property
+    def opt_rtl(self) -> bool:
+        return self in (self.rtl,)
+
+
+def add_arguments(np: Project, parser):
+    parser.set_defaults(func=partial(main, np))
+    match sorted(t.__name__ for t in np.cxxrtl_targets or []):
+        case []:
+            raise RuntimeError("no cxxrtl targets defined")
+        case [first, *rest]:
+            parser.add_argument(
+                "-t",
+                "--target",
+                choices=[first, *rest],
+                help="which CXXRTL target to build",
+                required=bool(rest),
+                **({"default": first} if not rest else {}),
+            )
+    parser.add_argument(
+        "-c",
+        "--compile",
+        action="store_true",
+        help="compile only; don't run",
+    )
+    parser.add_argument(
+        "-O",
+        "--optimize",
+        type=_Optimize,
+        choices=_Optimize,
+        help="build with optimizations (default: rtl)",
+        default=_Optimize.rtl,
+    )
+    parser.add_argument(
+        "-d",
+        "--debug",
+        action="store_true",
+        help="generate source-level debug information",
+    )
+    parser.add_argument(
+        "-v",
+        "--vcd",
+        action="store",
+        type=str,
+        help="output a VCD file",
+    )
+
+
+def main(np: Project, args):
+    yosys = find_yosys(lambda ver: ver >= (0, 10))
+
+    platform = np.cxxrtl_target_by_name(args.target)
+    design = construct_top(np, platform)
+
+    cxxrtl_cc_path = np.path.build(f"{np.name}.cc")
+    with logtime(logging.DEBUG, "elaboration"):
+        _cxxrtl_convert_with_header(
+            yosys,
+            cxxrtl_cc_path,
+            design,
+            np.name,
+            platform,
+            black_boxes={},
+        )
+
+    cc_o_paths = {
+        cxxrtl_cc_path: np.path.build(f"{np.name}.o"),
+    }
+    for path in np.path("cxxrtl").glob("*.cc"):
+        cc_o_paths[path] = np.path.build(f"{path.stem}.o")
+
+    cxxflags = CXXFLAGS + [
+        f"-DCLOCK_HZ={int(platform.default_clk_frequency)}",
+        *(["-O3"] if args.optimize.opt_rtl else ["-O0"]),
+        *(["-g"] if args.debug else []),
+    ]
+
+    procs = []
+    compile_commands = {}
+    for cc_path, o_path in cc_o_paths.items():
+        cmd = [
+            "c++",
+            *cxxflags,
+            f"-I{np.path("build")}",
+            f"-I{yosys.data_dir() / "include" / "backends" / "cxxrtl" / "runtime"}",
+            "-c",
+            str(cc_path),
+            "-o",
+            str(o_path),
+        ]
+        compile_commands[o_path] = cmd
+        logger.debug(" ".join(str(e) for e in cmd))
+        procs.append((cc_path, subprocess.Popen(cmd)))
+
+    with open(np.path.build("compile_commands.json"), "w") as f:
+        json.dump(
+            [
+                {
+                    "directory": str(np.path()),
+                    "file": str(file),
+                    "arguments": arguments,
+                }
+                for file, arguments in compile_commands.items()
+            ],
+            f,
+        )
+
+    failed = []
+    for cc_path, p in procs:
+        if p.wait() != 0:
+            failed.append(cc_path)
+
+    if failed:
+        logger.error("Failed to build paths:")
+        for p in failed:
+            logger.error(f"- {p}")
+        raise RuntimeError("failed compile step")
+
+    exe_o_path = np.path.build("cxxrtl")
+    cmd = [
+        "c++",
+        *cxxflags,
+        *cc_o_paths.values(),
+        "-o",
+        exe_o_path,
+    ]
+    logger.debug(" ".join(str(e) for e in cmd))
+    subprocess.run(cmd, check=True)
+
+    if not args.compile:
+        cmd = [exe_o_path]
+        if args.vcd:
+            cmd += ["--vcd", args.vcd]
+        logger.debug(" ".join(str(e) for e in cmd))
+        subprocess.run(cmd, check=True)
+
+
+def _cxxrtl_convert_with_header(
+    yosys: YosysBinary,
+    cc_out: Path,
+    design: Elaboratable,
+    name: str,
+    platform: CxxrtlPlatform,
+    *,
+    black_boxes: dict[Any, str],
+):
+    if cc_out.is_absolute():
+        try:
+            cc_out = cc_out.relative_to(Path.cwd())
+        except ValueError:
+            raise AssertionError(
+                "cc_out must be relative to cwd for builtin-yosys to write to it"
+            )
+    rtlil_text = rtlil.convert(design, name=name, platform=platform)
+    script = []
+    for box_source in black_boxes.values():
+        script.append(f"read_rtlil <<rtlil\n{box_source}\nrtlil")
+    script.append(f"read_rtlil <<rtlil\n{rtlil_text}\nrtlil")
+    script.append(f"write_cxxrtl -header {cc_out}")
+    yosys.run(["-q", "-"], "\n".join(script))
diff --git a/niar/cxxrtl_platform.py b/niar/cxxrtl_platform.py
new file mode 100644
index 0000000..e654e0b
--- /dev/null
+++ b/niar/cxxrtl_platform.py
@@ -0,0 +1,7 @@
+from abc import ABCMeta, abstractmethod
+
+__all__ = ["CxxrtlPlatform"]
+
+
+class CxxrtlPlatform(metaclass=ABCMeta):
+    default_clk_frequency = property(abstractmethod(lambda _: None))
diff --git a/niar/logger.py b/niar/logger.py
new file mode 100644
index 0000000..fddb946
--- /dev/null
+++ b/niar/logger.py
@@ -0,0 +1,37 @@
+import logging
+from contextlib import contextmanager
+from datetime import datetime
+from typing import Optional
+
+__all__ = ["logger", "logtime", "enable", "disable"]
+
+logging.basicConfig(
+    format="[%(asctime)s] %(name)s: %(levelname)s: %(message)s",
+    level=logging.DEBUG,
+)
+
+logger = logging.getLogger("niar")
+
+
+@contextmanager
+def logtime(level: int, activity: str, /, fail_level: Optional[int] = None):
+    global logger
+    start = datetime.now()
+    logger.log(level, "starting %s", activity)
+    try:
+        yield
+    except:
+        finish = datetime.now()
+        logger.log(fail_level or level, "%s failed in %s", activity, finish - start)
+        raise
+    else:
+        finish = datetime.now()
+        logger.log(level, "%s finished in %s", activity, finish - start)
+
+
+def disable():
+    logger.disabled = True
+
+
+def enable():
+    logger.disabled = False
diff --git a/niar/project.py b/niar/project.py
new file mode 100644
index 0000000..03d9324
--- /dev/null
+++ b/niar/project.py
@@ -0,0 +1,142 @@
+import sys
+from pathlib import Path
+from typing import Optional
+
+from amaranth import Elaboratable
+from amaranth.build import Platform
+
+from .cxxrtl_platform import CxxrtlPlatform
+
+__all__ = ["Project"]
+
+
+class Prop:
+    def __init__(
+        self,
+        name: str,
+        *,
+        description: str,
+        required: bool,
+        isinstance: Optional[type] = None,
+        issubclass: Optional[type] = None,
+        issubclass_list: Optional[type] = None,
+    ):
+        self.name = name
+        self.description = description
+        self.required = required
+        self.isinstance = isinstance
+        self.issubclass = issubclass
+        self.issubclass_list = issubclass_list
+
+    def validate(self, project):
+        assert not (
+            self.issubclass and self.issubclass_list
+        ), "may only define one of issubclass and issubclass_list"
+
+        if self.required:
+            assert hasattr(project, self.name), (
+                f"{project.__module__}.{project.__class__.__qualname__} is missing "
+                f"property {self.name!r} ({self.description})"
+            )
+        elif not hasattr(project, self.name):
+            return
+
+        attr = getattr(project, self.name)
+        if self.isinstance:
+            assert isinstance(attr, self.isinstance), (
+                f"{project.__module__}.{project.__class__.__qualname__} property "
+                f"{self.name!r} ({self.description}) should an instance of "
+                f"{self.isinstance!r}, but is {attr!r}"
+            )
+        if self.issubclass:
+            assert issubclass(attr, self.issubclass), (
+                f"{project.__module__}.{project.__class__.__qualname__} property "
+                f"{self.name!r} ({self.description}) should be a subclass of "
+                f"{self.issubclass!r}, but is {attr!r}"
+            )
+        if self.issubclass_list:
+            assert isinstance(attr, list)
+            for elem in attr:
+                assert issubclass(elem, self.issubclass_list), (
+                    f"{project.__module__}.{project.__class__.__qualname__} property "
+                    f"{self.name!r} ({self.description}) should be a list of subclasses of "
+                    f"{self.issubclass!r}, but has element {attr!r}"
+                )
+
+
+class Project:
+    name: str
+    top: type[Elaboratable]
+    targets: list[type[Platform]]
+    cxxrtl_targets: Optional[list[type[CxxrtlPlatform]]]
+
+    origin: Path
+
+    PROPS = [
+        Prop(
+            "name",
+            description="a keyword-like identifier for the project",
+            required=True,
+            isinstance=str,
+        ),
+        Prop(
+            "top",
+            description="a reference to the default top-level elaboratable to be built",
+            required=True,
+            issubclass=Elaboratable,
+        ),
+        Prop(
+            "targets",
+            description="a list of platform classes the elaboratable is targetted for",
+            required=True,
+            issubclass_list=Platform,
+        ),
+        Prop(
+            "cxxrtl_targets",
+            description="a list of niar.CxxrtlPlatform classes the elaboratable is targetted for",
+            required=False,
+            issubclass_list=CxxrtlPlatform,
+        ),
+    ]
+
+    def __init_subclass__(cls):
+        # We expect to be called from project-root/module/__init.py__ or similar;
+        # self.origin is project-root.
+        cls.origin = Path(sys._getframe(1).f_code.co_filename).parent.parent.absolute()
+        extras = cls.__dict__.keys() - {"__module__", "__doc__", "origin"}
+        for prop in cls.PROPS:
+            prop.validate(cls)
+            extras -= {prop.name}
+        assert extras == set(), f"unknown project properties: {extras}"
+
+    def target_by_name(self, name: str) -> Platform:
+        for t in self.targets:
+            if t.__name__ == name:
+                return t()
+        raise KeyError(f"unknown target {name!r}")
+
+    def cxxrtl_target_by_name(self, name: str) -> CxxrtlPlatform:
+        for t in self.cxxrtl_targets or []:
+            if t.__name__ == name:
+                return t()
+        raise KeyError(f"unknown CXXRTL target {name!r}")
+
+    def main(self):
+        from . import cli
+
+        cli(self)
+
+    @property
+    def path(self):
+        return ProjectPath(self)
+
+
+class ProjectPath:
+    def __init__(self, np: Project):
+        self.np = np
+
+    def __call__(self, *components):
+        return self.np.origin.joinpath(*components)
+
+    def build(self, *components):
+        return self("build", *components)
diff --git a/niar/test_cli.py b/niar/test_cli.py
new file mode 100644
index 0000000..9093a3c
--- /dev/null
+++ b/niar/test_cli.py
@@ -0,0 +1,32 @@
+import unittest
+from argparse import ArgumentParser
+
+from amaranth import Elaboratable, Module
+from amaranth_boards.icebreaker import ICEBreakerPlatform
+
+from . import Project, build, logger
+
+calling_test = False
+
+
+class FixtureTop(Elaboratable):
+    def elaborate(self, platform):
+        return Module()
+
+
+class FixtureProject(Project):
+    name = "fixture"
+    top = FixtureTop
+    targets = [ICEBreakerPlatform]
+
+
+class TestCLI(unittest.TestCase):
+    def setUp(self):
+        logger.disable()
+        self.addCleanup(logger.enable)
+
+    def test_build_works(self):
+        parser = ArgumentParser()
+        build.add_arguments(FixtureProject(), parser)
+        args, _argv = parser.parse_known_args()
+        args.func(args)
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..0a3ffb3
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,24 @@
+[project]
+name = "niar"
+version = "0.1"
+description = "A small framework for building projects with Amaranth"
+authors = [
+    {name = "Asherah Connor", email = "ashe@kivikakk.ee"},
+]
+dependencies = [
+    "amaranth >= 0.4.5, < 0.6",
+]
+requires-python = ">=3.8"
+license = {text = "BSD-2-Clause"}
+
+[project.optional-dependencies]
+build = [
+    "amaranth-boards",  # for test
+]
+
+[project.urls]
+Homepage = "https://github.com/kivikakk/niar"
+
+[build-system]
+requires = ["pdm-backend"]
+build-backend = "pdm.backend"