implement elf dynamic linking check

setup.py

@@ -33,6 +33,7 @@ setup(
         "cerberus",
         "inflection",
         "passlib",
+        "pyelftools",
         "requests",
         "srcinfo",
     ],

src/ahriman/models/package_archive.py

@@ -0,0 +1,95 @@
+#
+# Copyright (c) 2021-2023 ahriman team.
+#
+# This file is part of ahriman
+# (see https://github.com/arcan1s/ahriman).
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+from dataclasses import dataclass
+from pathlib import Path
+from typing import IO
+
+from elftools.elf.elffile import ELFFile
+from elftools.elf.dynamic import DynamicSection
+from pyalpm import Package  # type: ignore[import]
+
+from ahriman.core.util import walk
+
+
+@dataclass
+class PackageArchive:
+    """
+    helper for package archives
+    """
+
+    package: Package
+
+    @staticmethod
+    def get_depends_paths(package_base: str, root: Path) -> tuple[set[str], set[Path]]:
+        dependencies = set()
+        roots = set()
+
+        package_dir = root / "build" / package_base / "pkg"
+        for path in walk(package_dir):
+            dependencies.update(PackageArchive.get_dynamic(path))
+            roots.update(path.relative_to(package_dir).parents)
+
+        return dependencies, roots
+
+    @staticmethod
+    def get_dynamic(binary_path: Path) -> list[str]:
+        with binary_path.open("rb") as binary_file:
+            if not PackageArchive.is_elf(binary_file):
+                return []
+
+            elf_file = ELFFile(binary_file)
+            dynamic_section = next((section for section in elf_file.iter_sections() if isinstance(section, DynamicSection)), None)
+            if dynamic_section is None:
+                return []
+
+            return [tag.needed for tag in dynamic_section.iter_tags() if tag.entry.d_tag == "DT_NEEDED"]
+
+    @staticmethod
+    def get_filesystem(root: Path) -> dict[str, tuple[list[Path], list[Path]]]:
+        result = {}
+        for path in filter(lambda fn: fn.name == "files", walk(root / "var" / "lib" / "pacman" / "local")):
+            package, *_ = path.parent.name.rsplit("-", 2)
+
+            directories = []
+            files = []
+            for entry in path.read_text(encoding="utf8").splitlines():
+                if not entry or entry == "%FILES%":
+                    continue  # header
+                entry_path = Path(entry)
+                if entry_path.name == "":
+                    directories.append(entry_path)
+                else:
+                    files.append(entry_path)
+
+            result[package] = (directories, files)
+
+        return result
+
+    @staticmethod
+    def is_elf(descriptor: IO[bytes]) -> bool:
+        expected = b"\x7fELF"
+        length = len(expected)
+
+        magic_bytes = descriptor.read(length)
+        descriptor.seek(0)  # reset reading position
+
+        return magic_bytes == expected
+
+