refactor: make linux kbuild tree recipe-only

recipes/linux-kbuild-tree/all/conanfile.py

@@ -9,207 +9,87 @@ from conan.tools.build import cross_building
 from conan.tools.files import copy, get, save
 
 
-class LinuxKbuildTreeConan(ConanFile):
-    name = "linux-kbuild-tree"
-    package_type = "unknown"
-    upload_policy = "skip"
-    build_policy = "missing"
-
-    settings = "os", "arch", "compiler", "build_type"
-
-    options = {
-        "url": ["ANY"],
-        "defconfig": ["ANY"],
-        "make_modules": [True, False],
-    }
-
-    default_options = {
-        "url": "",
-        "defconfig": "defconfig",
-        "make_modules": False,
-    }
-
-    exports_sources = "configs/*"
-
-    def layout(self):
-        self.folders.build = "build"
-        self.folders.generators = os.path.join(self.folders.build, "generators")
-
-    def package_id(self):
-        c_compiler = self._compiler_executable("c")
-        if c_compiler is not None:
-            self.info.conf.define("tools.build:compiler_executables", {"c": str(c_compiler)})
-
-    def validate(self):
-        if self.settings.os != "Linux":
+def prepare(conanfile, output=None, defconfig=None, make_modules=None, url=None):
+    if conanfile.settings.os != "Linux":
         raise ConanInvalidConfiguration("linux-kbuild-tree requires a Linux target")
 
-        if not self.version:
-            raise ConanInvalidConfiguration(
-                "linux-kbuild-tree requires a package version, e.g. "
-                "conan create recipes/linux-kbuild-tree --version=6.5.9"
-            )
-
-        self._kernel_arch
-
-        if cross_building(self) and self._cross_compile is None:
+    pyreq = conanfile.python_requires["linux-kbuild-tree"]
+    version = str(pyreq.ref.version)
+    arch = kernel_arch(conanfile)
+    cross_compile = _cross_compile(conanfile)
+    if cross_compile is None:
         raise ConanInvalidConfiguration(
             "Cross-building a kernel tree requires "
             "tools.build:compiler_executables with a GCC-like C compiler"
         )
 
-    def source(self):
-        source_url, sha256 = self._linux_source()
-        get(
-            self,
-            source_url,
-            sha256=sha256,
-            destination=os.path.join(self.source_folder, "linux"),
-            strip_root=True,
+    if defconfig is None:
+        defconfig = conanfile.conf.get("user.linux-kbuild-tree:defconfig", default="defconfig")
+    if make_modules is None:
+        make_modules = conanfile.conf.get(
+            "user.linux-kbuild-tree:make_modules",
+            default=False,
         )
+    make_modules = _as_bool(make_modules)
+    if url is None:
+        url = conanfile.conf.get("user.linux-kbuild-tree:url", default=None)
 
-    def build(self):
-        linux = os.path.join(self.source_folder, "linux")
-        arch = self._kernel_arch
-        cross_compile = self._cross_compile or ""
-        jobs = self.conf.get("tools.build:jobs", default=None)
+    linux = output or os.path.join(conanfile.build_folder, "linux-kbuild-tree")
+    source_url, sha256 = _linux_source(pyreq.path, version, url=url)
+
+    if not os.path.exists(os.path.join(linux, "Makefile")):
+        get(conanfile, source_url, sha256=sha256, destination=linux, strip_root=True)
+
+    jobs = conanfile.conf.get("tools.build:jobs", default=None)
     make_jobs = f" -j{jobs}" if jobs else ""
-
     make_base = (
         f"make --no-print-directory -C {shlex.quote(linux)}{make_jobs} "
         f"ARCH={shlex.quote(str(arch))} "
-            f"CROSS_COMPILE={shlex.quote(str(cross_compile))} "
-            f"{self._host_warning_flags_args}"
+        f"CROSS_COMPILE={shlex.quote(str(cross_compile or ''))} "
+        f"{_host_warning_flags_args(version)}"
     )
 
-        self._install_config(linux, make_base)
+    _install_config(conanfile, pyreq.path, linux, make_base, defconfig)
+    conanfile.run(f"{make_base} olddefconfig prepare modules_prepare")
 
-        self.run(f"{make_base} olddefconfig prepare modules_prepare")
-
-        if self.options.make_modules:
+    if make_modules:
         # Required when CONFIG_MODVERSIONS=y and the target kernel exports
         # symbols that are not available from a vendor-provided Module.symvers.
-            self.run(f"{make_base} modules")
+        conanfile.run(f"{make_base} modules")
 
-        kernelrelease = self._capture(f"{make_base} kernelrelease")
-        compiler = self._capture(f"{self._cross_gcc} --version").splitlines()[0]
-        source_url, sha256 = self._linux_source()
+    kernelrelease = _capture(f"{make_base} kernelrelease")
+    compiler = _capture(f"{_cross_gcc(cross_compile)} --version").splitlines()[0]
+    info_path = os.path.join(linux, "kbuild-tree-info.txt")
 
     save(
-            self,
-            os.path.join(self.build_folder, "kbuild-tree-info.txt"),
+        conanfile,
+        info_path,
         "\n".join(
             [
                 f"url={source_url}",
-                    f"ref={self._linux_ref_from_version()}",
+                f"ref={_linux_ref_from_version(version)}",
                 f"sha256={sha256 or ''}",
                 f"kernelrelease={kernelrelease}",
                 f"arch={arch}",
-                    f"cross_compile={cross_compile}",
+                f"cross_compile={cross_compile or ''}",
                 f"compiler={compiler}",
-                    f"make_modules={self.options.make_modules}",
+                f"make_modules={make_modules}",
                 "",
             ]
         ),
     )
 
-    def package(self):
-        linux = os.path.join(self.source_folder, "linux")
+    return {
+        "path": linux,
+        "info_path": info_path,
+        "kernelrelease": kernelrelease,
+        "arch": arch,
+        "cross_compile": cross_compile or "",
+    }
 
-        # External module builds need source files, generated headers, scripts,
-        # .config, and often Module.symvers. Packaging the whole prepared tree is
-        # intentionally conservative and can be optimized after the flow is stable.
-        copy(self, "*", src=linux, dst=self.package_folder, excludes=(".git", ".git/*"))
-        copy(self, ".config", src=linux, dst=self.package_folder, keep_path=False)
-        copy(
-            self,
-            "kbuild-tree-info.txt",
-            src=self.build_folder,
-            dst=self.package_folder,
-            keep_path=False,
-        )
 
-    def package_info(self):
-        self.cpp_info.includedirs = []
-        self.cpp_info.libdirs = []
-        self.cpp_info.bindirs = []
-
-    def _linux_ref_from_version(self):
-        # Upstream Linux tags base releases as v6.8, while the kernel release
-        # and Conan package version are commonly represented as 6.8.0.
-        version_parts = str(self.version).split(".")
-        if len(version_parts) == 3 and version_parts[2] == "0":
-            return f"v{version_parts[0]}.{version_parts[1]}"
-        return f"v{self.version}"
-
-    def _linux_archive_version(self):
-        version_parts = str(self.version).split(".")
-        if len(version_parts) == 3 and version_parts[2] == "0":
-            return f"{version_parts[0]}.{version_parts[1]}"
-        return str(self.version)
-
-    def _linux_source(self):
-        source = self.conan_data.get("sources", {}).get(str(self.version)) or {}
-        source_url = source.get("url") or self._kernel_cdn_url()
-        return source_url, source.get("sha256")
-
-    def _kernel_cdn_url(self):
-        archive_version = self._linux_archive_version()
-        major = archive_version.split(".", 1)[0]
-        return (
-            f"https://cdn.kernel.org/pub/linux/kernel/v{major}.x/"
-            f"linux-{archive_version}.tar.gz"
-        )
-
-    @property
-    def _host_warning_flags_args(self):
-        hostcflags = []
-
-        if self._version_lt("5.16.0") and self._host_compiler_accepts(
-            "-Wno-error=use-after-free"
-        ):
-            # Older objtool builds use -Werror and trip GCC 14's realloc(ptr)
-            # use-after-free diagnostic in tools/lib/subcmd/subcmd-util.h.
-            hostcflags.append("-Wno-error=use-after-free")
-
-        if not hostcflags:
-            return ""
-
-        flags = shlex.quote(" ".join(hostcflags))
-        return f"HOSTCFLAGS={flags} EXTRA_CFLAGS={flags}"
-
-    def _host_compiler_accepts(self, flag):
-        try:
-            subprocess.run(
-                [
-                    "gcc",
-                    flag,
-                    "-x",
-                    "c",
-                    "-c",
-                    "-o",
-                    os.devnull,
-                    "-",
-                ],
-                input="int main(void) { return 0; }\n",
-                text=True,
-                stdout=subprocess.DEVNULL,
-                stderr=subprocess.DEVNULL,
-                check=True,
-            )
-        except (OSError, subprocess.CalledProcessError):
-            return False
-        return True
-
-    def _version_lt(self, other):
-        return self._version_tuple(str(self.version)) < self._version_tuple(other)
-
-    def _version_tuple(self, version):
-        return tuple(int(part) for part in version.split("."))
-
-    @property
-    def _kernel_arch(self):
-        arch = str(self.settings.arch)
+def kernel_arch(conanfile):
+    arch = str(conanfile.settings.arch)
     arch_map = {
         "x86": "x86",
         "x86_64": "x86",
@@ -245,57 +125,169 @@ class LinuxKbuildTreeConan(ConanFile):
         )
     return arch_map[arch]
 
-    @property
-    def _cross_compile(self):
-        if not cross_building(self):
+
+def _linux_ref_from_version(version):
+    # Upstream Linux tags base releases as v6.8, while the kernel release
+    # and Conan package version are commonly represented as 6.8.0.
+    version_parts = str(version).split(".")
+    if len(version_parts) == 3 and version_parts[2] == "0":
+        return f"v{version_parts[0]}.{version_parts[1]}"
+    return f"v{version}"
+
+
+def _linux_archive_version(version):
+    version_parts = str(version).split(".")
+    if len(version_parts) == 3 and version_parts[2] == "0":
+        return f"{version_parts[0]}.{version_parts[1]}"
+    return str(version)
+
+
+def _linux_source(recipe_path, version, url=None):
+    source = _conandata_sources(recipe_path).get(str(version), {})
+    source_url = url or source.get("url") or _kernel_cdn_url(version)
+    return source_url, source.get("sha256")
+
+
+def _kernel_cdn_url(version):
+    archive_version = _linux_archive_version(version)
+    major = archive_version.split(".", 1)[0]
+    return (
+        f"https://cdn.kernel.org/pub/linux/kernel/v{major}.x/"
+        f"linux-{archive_version}.tar.gz"
+    )
+
+
+def _conandata_sources(recipe_path):
+    path = os.path.join(recipe_path, "conandata.yml")
+    if not os.path.isfile(path):
+        return {}
+
+    sources = {}
+    current = None
+    in_sources = False
+    with open(path, encoding="utf-8") as conandata:
+        for raw_line in conandata:
+            line = raw_line.rstrip()
+            stripped = line.strip()
+            if not stripped or stripped.startswith("#"):
+                continue
+            if stripped == "sources:":
+                in_sources = True
+                continue
+            if not in_sources:
+                continue
+            if not line.startswith("  "):
+                break
+            version_match = re.match(r'^\s{2}"?([^":]+)"?:\s*$', line)
+            if version_match:
+                current = version_match.group(1)
+                sources[current] = {}
+                continue
+            field_match = re.match(r'^\s{4}([A-Za-z0-9_-]+):\s*"?([^"]*)"?\s*$', line)
+            if current and field_match:
+                key, value = field_match.groups()
+                sources[current][key] = value
+    return sources
+
+
+def _host_warning_flags_args(version):
+    hostcflags = []
+
+    if _version_lt(version, "5.16.0") and _host_compiler_accepts("-Wno-error=use-after-free"):
+        # Older objtool builds use -Werror and trip GCC 14's realloc(ptr)
+        # use-after-free diagnostic in tools/lib/subcmd/subcmd-util.h.
+        hostcflags.append("-Wno-error=use-after-free")
+
+    if not hostcflags:
         return ""
 
-        c_compiler = self._compiler_executable("c")
+    flags = shlex.quote(" ".join(hostcflags))
+    return f"HOSTCFLAGS={flags} EXTRA_CFLAGS={flags}"
+
+
+def _as_bool(value):
+    if isinstance(value, str):
+        return value.lower() in ("1", "true", "yes", "on")
+    return bool(value)
+
+
+def _host_compiler_accepts(flag):
+    try:
+        subprocess.run(
+            [
+                "gcc",
+                flag,
+                "-x",
+                "c",
+                "-c",
+                "-o",
+                os.devnull,
+                "-",
+            ],
+            input="int main(void) { return 0; }\n",
+            text=True,
+            stdout=subprocess.DEVNULL,
+            stderr=subprocess.DEVNULL,
+            check=True,
+        )
+    except (OSError, subprocess.CalledProcessError):
+        return False
+    return True
+
+
+def _version_lt(version, other):
+    return _version_tuple(str(version)) < _version_tuple(other)
+
+
+def _version_tuple(version):
+    return tuple(int(part) for part in version.split("."))
+
+
+def _cross_compile(conanfile):
+    if not cross_building(conanfile):
+        return ""
+
+    c_compiler = _compiler_executable(conanfile, "c")
     if not c_compiler:
         return None
 
-        return self._cross_compile_from_executable(c_compiler)
+    return _cross_compile_from_executable(c_compiler)
 
-    def _cross_compile_from_compiler_executables(self):
-        c_compiler = self._compiler_executable("c")
-        if not c_compiler:
-            return None
-        return self._cross_compile_from_executable(c_compiler)
 
-    def _cross_compile_from_executable(self, c_compiler):
+def _cross_compile_from_executable(c_compiler):
     executable = os.path.basename(c_compiler)
     match = re.match(r"^(.+?)(?:gcc|cc)(?:-\d+(?:\.\d+)*)?$", executable)
     if not match:
         return None
     return match.group(1)
 
-    @property
-    def _cross_gcc(self):
-        cross_compile = self._cross_compile or ""
-        return shlex.quote(f"{cross_compile}gcc")
 
-    def _compiler_executable(self, language):
-        executables = self.conf.get("tools.build:compiler_executables", default={})
+def _cross_gcc(cross_compile):
+    return shlex.quote(f"{cross_compile or ''}gcc")
+
+
+def _compiler_executable(conanfile, language):
+    executables = conanfile.conf.get("tools.build:compiler_executables", default={})
     if not executables:
         return None
     if hasattr(executables, "get"):
         return executables.get(language)
     return None
 
-    def _install_config(self, linux, make_base):
-        defconfig = str(self.options.defconfig)
+
+def _install_config(conanfile, recipe_path, linux, make_base, defconfig):
+    defconfig = "" if defconfig is None else str(defconfig)
     if not defconfig:
         if not os.path.exists(os.path.join(linux, ".config")):
             raise ConanInvalidConfiguration(
-                    "Missing kernel config: set linux-kbuild-tree/*:defconfig "
-                    "or provide a source tree with .config"
+                "Missing kernel config: pass defconfig or provide a source tree with .config"
             )
         return
 
-        exported_config = os.path.join(self.source_folder, "configs", defconfig)
+    exported_config = os.path.join(recipe_path, "configs", defconfig)
     if os.path.isfile(exported_config):
         copy(
-                self,
+            conanfile,
             defconfig,
             src=os.path.dirname(exported_config),
             dst=linux,
@@ -304,9 +296,10 @@ class LinuxKbuildTreeConan(ConanFile):
         os.replace(os.path.join(linux, defconfig), os.path.join(linux, ".config"))
         return
 
-        self.run(f"{make_base} {shlex.quote(defconfig)}")
+    conanfile.run(f"{make_base} {shlex.quote(defconfig)}")
 
-    def _capture(self, command):
+
+def _capture(command):
     output = subprocess.check_output(
         command,
         shell=True,
@@ -316,3 +309,11 @@ class LinuxKbuildTreeConan(ConanFile):
     if not output:
         raise ConanInvalidConfiguration(f"Command produced no output: {command}")
     return output
+
+
+class LinuxKbuildTreeConan(ConanFile):
+    name = "linux-kbuild-tree"
+    package_type = "python-require"
+    upload_policy = "skip"
+
+    exports = "configs/*"

recipes/linux-kbuild-tree/all/test_package/conanfile.py

@@ -8,23 +8,26 @@ from conan.tools.files import copy
 
 class TestPackageConan(ConanFile):
     test_type = "explicit"
+    python_requires = "tested_reference_str"
 
     settings = "os", "compiler", "build_type", "arch"
     exports_sources = "Makefile", "test_kbuild_module.c"
 
-    def requirements(self):
-        self.requires(self.tested_reference_str)
-
     def layout(self):
         self.folders.build = "build"
         self.folders.generators = os.path.join(self.folders.build, "generators")
 
     def build(self):
-        kernel_tree = self.dependencies["linux-kbuild-tree"].package_folder
+        linux_kbuild_tree = self.python_requires["linux-kbuild-tree"].module
+        tree_info = linux_kbuild_tree.prepare(
+            self,
+            output=os.path.join(self.build_folder, "linux-kbuild-tree"),
+        )
+
+        kernel_tree = tree_info["path"]
         module_dir = os.path.join(self.build_folder, "module")
         copy(self, "*", src=self.source_folder, dst=module_dir)
 
-        tree_info = self._read_tree_info(kernel_tree)
         arch = tree_info.get("arch", "")
         cross_compile = tree_info.get("cross_compile", "")
         jobs = self.conf.get("tools.build:jobs", default=None)
@@ -44,18 +47,3 @@ class TestPackageConan(ConanFile):
         module_path = os.path.join(self.build_folder, "module", "test_kbuild_module.ko")
         if not os.path.isfile(module_path):
             raise ConanException(f"Kernel module was not built: {module_path}")
-
-    def _read_tree_info(self, kernel_tree):
-        path = os.path.join(kernel_tree, "kbuild-tree-info.txt")
-        if not os.path.isfile(path):
-            raise ConanException(f"Missing linux-kbuild-tree metadata: {path}")
-
-        result = {}
-        with open(path, encoding="utf-8") as tree_info:
-            for line in tree_info:
-                line = line.strip()
-                if not line or "=" not in line:
-                    continue
-                key, value = line.split("=", 1)
-                result[key] = value
-        return result