Refactor stage2

In this change I reverted some plain variables back to
@property method and throws NotImplementedError. Because this pattern
caused too many trouble with mypy and pylint.

Rather than # disable everywhere, I'd just fold and use @property.

Change-Id: I8660b6fb41ce89d9d5d3d159adce6feeb449eab8

1 files changed, 51 insertions, 7 deletions

diff --git a/toolchains.py b/toolchains.py
index 37cbc89..3c747e1 100644
--- a/toolchains.py
+++ b/toolchains.py
@@ -20,26 +20,66 @@ from pathlib import Path
 import constants
 import hosts
 import paths
+import version
 
 class Toolchain:
     """Base toolchain."""
 
-    cc: Path  # pylint: disable=invalid-name
-    cxx: Path
     path: Path
 
+    @property
+    def cc(self) -> Path:  # pylint: disable=invalid-name
+        """Returns the path to c compiler."""
+        raise NotImplementedError()
+
+    @property
+    def cxx(self) -> Path:
+        """Returns the path to c++ compiler."""
+        raise NotImplementedError()
+
+    @property
+    def lib_dir(self) -> Path:
+        """Returns the path to lib dir."""
+        raise NotImplementedError()
+
+    def get_resource_dir(self, arch: str = '') -> Path:
+        """Returns resource dir path for an arch."""
+        raise NotImplementedError()
+
 
 class _HostToolchain(Toolchain):
     """Base toolchain that compiles host binary."""
 
+    def __init__(self, path: Path) -> None:
+        self.path = path
+
     @property
-    def cc(self) -> Path:  # type: ignore
+    def cc(self) -> Path:  # pylint: disable=invalid-name
         return self.path / 'bin' / 'clang'
 
     @property
-    def cxx(self) -> Path:  # type: ignore
+    def cxx(self) -> Path:
+        """Returns the path to c++ compiler."""
         return self.path / 'bin' / 'clang++'
 
+    @property
+    def lib_dir(self) -> Path:
+        """Returns the path to lib dir."""
+        return self.path / 'lib64'
+
+    @property
+    def _version_file(self) -> Path:
+        return self.path / 'include' / 'clang' / 'Basic'/ 'Version.inc'
+
+    @property
+    def _version(self) -> version.Version:
+        return version.Version(self._version_file)
+
+    def get_resource_dir(self, arch: str = '') -> Path:
+        """Returns the path to resource dir."""
+        return (self.lib_dir / 'clang' / self._version.long_version() /
+                'lib' / 'linux' / arch)
+
 
 def _clang_prebuilt_path(host: hosts.Host) -> Path:
     """Returns the path to prebuilt clang toolchain."""
@@ -47,7 +87,11 @@ def _clang_prebuilt_path(host: hosts.Host) -> Path:
             host.os_tag / constants.CLANG_PREBUILT_VERSION)
 
 
-class PrebuiltToolchain(_HostToolchain):
-    """A prebuilt toolchain used to build stage1."""
+def build_toolchain_for_path(path: Path) -> Toolchain:
+    """Returns a toolchain object for a given path."""
+    return _HostToolchain(path)
+
 
-    path: Path = _clang_prebuilt_path(hosts.build_host())
+def get_prebuilt_toolchain() -> Toolchain:
+    """Returns the prebuilt toolchain."""
+    return build_toolchain_for_path(_clang_prebuilt_path(hosts.build_host()))