Updated Verilator to not reply on system python

Author: abrisco

.bazelrc

@@ -37,3 +37,14 @@ test:ciremotebuild --tls_client_certificate=/root/.ssh/buildbuddy-cert.pem
 test:ciremotebuild --tls_client_key=/root/.ssh/buildbuddy-key.pem
 test:ciremotebuild --build_metadata=VISIBILITY=PUBLIC
 test:ciremotebuild --remote_timeout=3600
+
+###############################################################################
+## User flags
+###############################################################################
+# Optionally allow users to define custom flags when developing new features.
+# https://bazel.build/configure/best-practices#bazelrc-file
+#
+# Note: This line should always be last in this file to ensure consistent behavior
+# with flags defined in this file.
+#
+try-import %workspace$/user.bazelrc

.gitignore

@@ -1,4 +1,5 @@
 bazel-*/
 bazel-*
+user.bazelrc
 MODULE.bazel
 MODULE.bazel.lock

dependency_support/verilator/BUILD renamed to dependency_support/verilator/BUILD.bazel

@@ -0,0 +1,13 @@
+load("@rules_python//python:defs.bzl", "py_binary")
+
+py_binary(
+    name = "verilator_astgen",
+    srcs = ["verilator_astgen.py"],
+    visibility = ["@verilator//:__pkg__"],
+)
+
+py_binary(
+    name = "verilator_flexfix",
+    srcs = ["verilator_flexfix.py"],
+    visibility = ["@verilator//:__pkg__"],
+)

dependency_support/verilator/private/BUILD.bazel

@@ -0,0 +1,70 @@
+"""A process wrapper for running Verilator's astgen tool in a Bazel action."""
+
+import argparse
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+
+
+def parse_args() -> argparse.Namespace:
+    """Parse command line arguments"""
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument(
+        "--src",
+        dest="srcs",
+        type=Path,
+        action="append",
+        required=True,
+        help="Sources that need to appear in include paths.",
+    )
+
+    parser.add_argument(
+        "--out",
+        dest="outputs",
+        type=Path,
+        action="append",
+        required=True,
+        help="The expected output files.",
+    )
+
+    parser.add_argument(
+        "--astgen", type=Path, required=True, help="The path to the astgen tool."
+    )
+
+    parser.add_argument(
+        "astgen_args",
+        nargs="*",
+        help="Remaining args to forward to astgen.",
+    )
+
+    return parser.parse_args()
+
+
+def main() -> None:
+    """The main entrypoint"""
+    args = parse_args()
+
+    includes = []
+    for parent in set(path.parent for path in args.srcs):
+        includes.extend(["-I", str(parent)])
+
+    result = subprocess.run(
+        [sys.executable, str(args.astgen)] + includes + args.astgen_args,
+        check=False,
+        stderr=subprocess.STDOUT,
+        stdout=subprocess.PIPE,
+        encoding="utf-8",
+    )
+
+    if result.returncode:
+        print(result.stdout, file=sys.stderr)
+        sys.exit(result.returncode)
+
+    for out in args.outputs:
+        shutil.copyfile(out.name, out)
+
+
+if __name__ == "__main__":
+    main()

dependency_support/verilator/private/verilator_astgen.py

@@ -0,0 +1,65 @@
+"""A process wrapper for running Verilator's flexfix tool in a Bazel action."""
+
+import argparse
+import subprocess
+import sys
+from pathlib import Path
+
+
+def parse_args() -> argparse.Namespace:
+    """Parse command line arguments"""
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument(
+        "--flexfix",
+        type=Path,
+        required=True,
+        help="The path to `flexfix`.",
+    )
+
+    parser.add_argument(
+        "--src",
+        type=Path,
+        required=True,
+        help="The input source file to pass to `flexfix`",
+    )
+
+    parser.add_argument(
+        "--output",
+        type=Path,
+        required=True,
+        help="The path to the output file the action must produce.",
+    )
+
+    parser.add_argument(
+        dest="flexfix_args",
+        nargs="*",
+        help="Additional args to be passed to `flexfix`.",
+    )
+
+    return parser.parse_args()
+
+
+def main() -> None:
+    """The main entrypoint"""
+    args = parse_args()
+
+    with args.src.open() as handle:
+        result = subprocess.run(
+            [sys.executable, args.flexfix] + args.flexfix_args,
+            stdin=handle,
+            check=False,
+            stderr=subprocess.STDOUT,
+            stdout=subprocess.PIPE,
+            encoding="utf-8",
+        )
+
+        if result.returncode:
+            print(result.stdout, file=sys.stderr)
+            sys.exit(result.returncode)
+
+    args.output.write_text(result.stdout, encoding="utf-8")
+
+
+if __name__ == "__main__":
+    main()

dependency_support/verilator/private/verilator_flexfix.py

@@ -0,0 +1,167 @@
+"""Utility rules used to compile Verilator"""
+
+def _verilator_astgen_impl(ctx):
+    args = ctx.actions.args()
+    args.add("--astgen", ctx.file.astgen)
+    args.add_all(ctx.files.srcs, format_each = "--src=%s")
+    args.add_all(ctx.outputs.outs, format_each = "--out=%s")
+    args.add("--")
+    args.add_all(ctx.attr.args)
+
+    ctx.actions.run(
+        executable = ctx.executable._process_wrapper,
+        mnemonic = "VerilatorASTgen",
+        arguments = [args],
+        inputs = ctx.files.srcs,
+        outputs = ctx.outputs.outs,
+        tools = [ctx.file.astgen],
+    )
+
+    return [DefaultInfo(
+        files = depset(ctx.outputs.outs),
+    )]
+
+verilator_astgen = rule(
+    doc = "Run Verilator's `astgen` tool and collect the requested outputs.",
+    implementation = _verilator_astgen_impl,
+    attrs = {
+        "args": attr.string_list(
+            doc = "The command line arugments for `astgen`.",
+        ),
+        "astgen": attr.label(
+            doc = "The path to the `astgen` tool.",
+            allow_single_file = True,
+            mandatory = True,
+        ),
+        "outs": attr.output_list(
+            doc = "The output sources generated by `astgen`.",
+            allow_empty = False,
+            mandatory = True,
+        ),
+        "srcs": attr.label_list(
+            doc = "Input sources for `astgen`.",
+            allow_files = True,
+        ),
+        "_process_wrapper": attr.label(
+            cfg = "exec",
+            executable = True,
+            default = Label("//dependency_support/verilator/private:verilator_astgen"),
+        ),
+    },
+)
+
+def _is_expandable(value):
+    for prefix in ("$(execpath", "$(location"):
+        if prefix in value:
+            return True
+
+    return False
+
+def _verilator_bisonpre_impl(ctx):
+    data = [ctx.attr.bisonpre] + ctx.attr.srcs + ctx.attr.tools
+    args = [
+        ctx.expand_location(a, data) if _is_expandable(a) else a
+        for a in ctx.attr.args
+    ]
+    envs = {
+        # Expand $(location) / $(locations) in the values.
+        k: ctx.expand_location(v, data) if _is_expandable(v) else v
+        for k, v in ctx.attr.env.items()
+    }
+    ctx.actions.run(
+        outputs = ctx.outputs.outs,
+        inputs = ctx.files.srcs,
+        tools = [ctx.executable.bisonpre] + ctx.files.tools,
+        executable = ctx.executable.bisonpre,
+        arguments = args,
+        mnemonic = "VerilatorBisonPre",
+        use_default_shell_env = False,
+        env = envs,
+    )
+    return DefaultInfo(
+        files = depset(ctx.outputs.outs),
+        runfiles = ctx.runfiles(files = ctx.outputs.outs),
+    )
+
+verilator_bisonpre = rule(
+    doc = "Run Verilator's `bisonpre` tool and collect the requested outputs.",
+    implementation = _verilator_bisonpre_impl,
+    attrs = {
+        "args": attr.string_list(
+            doc = "Command line arguments of the `bisonpre`",
+        ),
+        "bisonpre": attr.label(
+            doc = "The path to the `bisonpre` tool.",
+            executable = True,
+            mandatory = True,
+            cfg = "exec",
+        ),
+        "env": attr.string_dict(
+            doc = "Environment variables of the action.",
+        ),
+        "outs": attr.output_list(
+            mandatory = True,
+            doc = "Output files generated by the action.",
+        ),
+        "srcs": attr.label_list(
+            allow_files = True,
+            doc = "Additional inputs of the action.",
+        ),
+        "tools": attr.label_list(
+            allow_files = True,
+            cfg = "exec",
+            doc = "Additional tools of the action.",
+        ),
+    },
+)
+
+def _verilator_flexfix_impl(ctx):
+    args = ctx.actions.args()
+    args.add("--flexfix", ctx.file.flexfix)
+    args.add("--src", ctx.file.src)
+    args.add("--output", ctx.outputs.out)
+    args.add("--")
+    args.add_all(ctx.attr.args)
+
+    ctx.actions.run(
+        executable = ctx.executable._process_wrapper,
+        mnemonic = "VerilatorFlexFix",
+        outputs = [ctx.outputs.out],
+        inputs = [ctx.file.src],
+        tools = [ctx.file.flexfix],
+        arguments = [args],
+    )
+
+    return [DefaultInfo(
+        files = depset([ctx.outputs.out]),
+    )]
+
+verilator_flexfix = rule(
+    doc = "Run Verilator's `flexfix` tool and collect the requested outputs.",
+    implementation = _verilator_flexfix_impl,
+    attrs = {
+        "args": attr.string_list(
+            doc = "The command line arugments for `flexfix`.",
+        ),
+        "flexfix": attr.label(
+            doc = "The path to the `flexfix` tool.",
+            cfg = "exec",
+            allow_single_file = True,
+            mandatory = True,
+        ),
+        "out": attr.output(
+            doc = "The output source generated by `flexfix`.",
+            mandatory = True,
+        ),
+        "src": attr.label(
+            doc = "The source file to pass to `flexfix`.",
+            mandatory = True,
+            allow_single_file = True,
+        ),
+        "_process_wrapper": attr.label(
+            cfg = "exec",
+            executable = True,
+            default = Label("//dependency_support/verilator/private:verilator_flexfix"),
+        ),
+    },
+)