build(protocan): добавь host-сборку без CMake

c/protocan-transport/README.md

@@ -104,6 +104,12 @@ Android-проект подключает `ports/android/Android.mk` и доба
 `ports/android/kotlin` в `sourceSets`. JNI-код занимается только преобразованием
 типов и временем жизни parser context, а правила кадра и CAN ID остаются в C.
 
+Если на Windows нет CMake, host-библиотеку тем же MSVC можно собрать так:
+
+```powershell
+python tools/build_host.py --output native/setcore.dll
+```
+
 Либо напрямую:
 
 ```bash

c/protocan-transport/tools/build_host.py

@@ -0,0 +1,86 @@
+"""Build the SETCore shared library without imposing one host toolchain.
+
+CMake remains the primary build.  On a Windows workstation where CMake is
+absent, the script locates Visual Studio and invokes MSVC directly.  Unix-like
+hosts fall back to the system C compiler.
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import platform
+import shutil
+import subprocess
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parent.parent
+INCLUDE = ROOT / "include"
+SOURCES = [
+    ROOT / "src" / name for name in (
+        "pcan_abi.c", "pcan_crc.c", "pcan_frame.c", "pcan_id.c",
+        "pcan_link.c", "pcan_ring.c", "pcan_gas.c",
+    )
+]
+
+
+def _visual_studio_vcvars() -> Path | None:
+    installer = Path(os.environ.get("ProgramFiles(x86)", r"C:\Program Files (x86)"))
+    vswhere = installer / "Microsoft Visual Studio" / "Installer" / "vswhere.exe"
+    if vswhere.exists():
+        result = subprocess.run(
+            [str(vswhere), "-latest", "-products", "*",
+             "-requires", "Microsoft.VisualStudio.Component.VC.Tools.x86.x64",
+             "-property", "installationPath"],
+            text=True, capture_output=True, check=False,
+        )
+        if result.returncode == 0 and result.stdout.strip():
+            candidate = (Path(result.stdout.strip()) / "VC" / "Auxiliary" /
+                         "Build" / "vcvars64.bat")
+            if candidate.exists():
+                return candidate
+    return None
+
+
+def _build_msvc(output: Path, build_dir: Path) -> None:
+    vcvars = _visual_studio_vcvars()
+    if vcvars is None:
+        raise SystemExit("Visual Studio C++ tools were not found")
+    quoted_sources = " ".join(f'"{source}"' for source in SOURCES)
+    command = (
+        f'call "{vcvars}" && cl /nologo /W4 /std:c11 '
+        f'/DPCAN_ABI_BUILD_DLL /I"{INCLUDE}" /LD {quoted_sources} '
+        f'/Fe:"{output}"'
+    )
+    subprocess.run(["cmd.exe", "/d", "/c", command], cwd=build_dir, check=True)
+
+
+def _build_cc(output: Path, build_dir: Path) -> None:
+    compiler = shutil.which("cc") or shutil.which("clang") or shutil.which("gcc")
+    if compiler is None:
+        raise SystemExit("C compiler was not found")
+    command = [compiler, "-std=c99", "-Wall", "-Wextra", "-Wpedantic",
+               "-fPIC", "-shared", f"-I{INCLUDE}", *map(str, SOURCES),
+               "-o", str(output)]
+    subprocess.run(command, cwd=build_dir, check=True)
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--output", type=Path, required=True)
+    args = parser.parse_args()
+    output = args.output.resolve()
+    output.parent.mkdir(parents=True, exist_ok=True)
+    build_dir = output.parent / ".setcore-build"
+    build_dir.mkdir(parents=True, exist_ok=True)
+    if platform.system() == "Windows":
+        _build_msvc(output, build_dir)
+    else:
+        _build_cc(output, build_dir)
+    print(output)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())