Add base tool

RustPython · youknowone · Sep 3, 2025 · Aug 31, 2025 · Aug 31, 2025 · Aug 31, 2025
commit 59d61a5f4a6cf9d73eaec7ac3988f8d39e1c7bfc
diff --git a/scripts/libc_posix.py b/scripts/libc_posix.py
@@ -0,0 +1,119 @@
+#!/usr/bin/env python
+import collections
+import re
+import urllib.request
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from collections.abc import Iterator
+
+CONSTS_PAT = re.compile(r"\b_*[A-Z]+(?:_+[A-Z]+)*_*\b")
+OS_CONSTS_PAT = re.compile(
+    r"\bos\.(_*[A-Z]+(?:_+[A-Z]+)*_*)"
+)  # TODO: Exclude matches if they have `(` after (those are functions)
+
+
+LIBC_VERSION = "0.2.175"
+
+EXCLUDE = frozenset(
+    {
+        # Defined at `vm/src/stdlib/os.rs`
+        "O_APPEND",
+        "O_CREAT",
+        "O_EXCL",
+        "O_RDONLY",
+        "O_RDWR",
+        "O_TRUNC",
+        "O_WRONLY",
+        "SEEK_CUR",
+        "SEEK_END",
+        "SEEK_SET",
+        # Functions, not consts
+        "WCOREDUMP",
+        "WIFCONTINUED",
+        "WIFSTOPPED",
+        "WIFSIGNALED",
+        "WIFEXITED",
+        "WEXITSTATUS",
+        "WSTOPSIG",
+        "WTERMSIG",
+        # False positive
+        # "EOF",
+    }
+)
+
+
+def build_url(fname: str) -> str:
+    return f"https://raw.githubusercontent.com/rust-lang/libc/refs/tags/{LIBC_VERSION}/libc-test/semver/{fname}.txt"
+
+
+TARGET_OS = {
+    "android": "android",
+    "dragonfly": "dragonfly",
+    "freebsd": "freebsd",
+    "linux": "linux",
+    "macos": "apple",
+    "netbsd": "netbsd",
+    "openbsd": "openbsd",
+    "redox": "redox",
+    # solaris?
+}
+
+
+def get_consts(url: str, pattern: re.Pattern = CONSTS_PAT) -> frozenset[str]:
+    with urllib.request.urlopen(url) as f:
+        resp = f.read().decode()
+
+    return frozenset(pattern.findall(resp)) - EXCLUDE
+
+
+def format_groups(groups: dict) -> "Iterator[tuple[str, str]]":
+    # sort by length, then alphabet. so we will have a consistent output
+    for targets, consts in sorted(
+        groups.items(), key=lambda t: (len(t[0]), sorted(t[0]))
+    ):
+        cond = ", ".join(f'target_os = "{target_os}"' for target_os in sorted(targets))
+        if len(targets) > 1:
+            cond = f"any({cond})"
+        cfg = f"#[cfg({cond})]"
+
+        imports = ", ".join(sorted(consts))
+        use = f"use libc::{{{imports}}};"
+        yield cfg, use
+
+
+def main():
+    wanted_consts = get_consts(
+        "https://docs.python.org/3.13/library/os.html",  # Should we read from https://github.com/python/cpython/blob/bcee1c322115c581da27600f2ae55e5439c027eb/Modules/posixmodule.c#L17023 instead?
+        pattern=OS_CONSTS_PAT,
+    )
+    available = {
+        target_os: get_consts(build_url(fname))
+        for target_os, fname in TARGET_OS.items()
+    }
+
+    group_consts = collections.defaultdict(set)
+    for const in wanted_consts:
+        target_oses = frozenset(
+            target_os for target_os, consts in available.items() if const in consts
+        )
+        if not target_oses:
+            continue
+
+        group_consts[target_oses].add(const)
+    group_consts = dict(group_consts)
+
+    code = "\n\n".join(
+        f"""
+{cfg}
+#[pyattr]
+{use}
+""".strip()
+        for cfg, use in format_groups(group_consts)
+    )
+
+    print(code)
+
+
+if __name__ == "__main__":
+    main()