feat: basically finish pkgconfig generation

packer/src/sarasacw_omrf_packer/renders/cmake.py

@@ -65,9 +65,9 @@ class CMakeProperties:
                 "bad target name component in CMake. consider manually specifying it"
             )
         if self.artifact_dll == "":
-            raise ValueError("bad artifact dll file name")
+            raise ValueError("bad artifact dll file name in CMake")
         if self.artifact_lib == "":
-            raise ValueError("bad artifact lib file name")
+            raise ValueError("bad artifact lib file name in CMake")
         if self.version.prerelease is not None or self.version.build is not None:
             raise ValueError(
                 "unsupported semantic version components (prerelease or build) in CMake"

packer/src/sarasacw_omrf_packer/renders/pkgconfig.py

@@ -1,21 +1,90 @@
+"""Renderer for pkg-config package files.
+
+Generates the ``<pkg>.pc`` file consumed by the ``pkg-config`` tool so that the
+distributed Rust FFI library can be located and linked by downstream build
+systems. The data fed to the template is carried by
+:class:`PkgConfigProperties`, and :class:`PkgConfigRender` performs the
+rendering on top of :class:`renders.common.BaseRender`.
+"""
+
 from dataclasses import dataclass
 from typing import Any
 from . import common
+from semver import Version
+
 
 @dataclass(frozen=True)
 class PkgConfigProperties:
-    pass
+    """Inputs required to render the pkg-config ``.pc`` file.
+
+    A frozen dataclass validated in :meth:`__post_init__`; once constructed, an
+    instance is guaranteed to hold only values that are safe to substitute into
+    the ``.pc`` template.
+    """
+
+    name: str
+    """Human-readable name of the library or package.
+
+    This is purely descriptive; the ``pkg-config`` tool itself resolves
+    packages by the file name of the ``.pc`` file, not by this field.
+    """
+    description: str
+    """Brief description of the package."""
+
+    artifact: str
+    """Name of the build artifact.
+
+    ``pkg-config`` uses this value to determine which dynamic library to link.
+    For an artifact named ``XXX``, it looks for ``libXXX.so`` on Linux and
+    ``XXX.lib`` or ``libXXX.dll.a`` on Windows.
+    """
+
+    version: Version
+    """Version of the library. Must not carry a prerelease or build component."""
+
+    def __post_init__(self) -> None:
+        """Validate the fields after construction.
+
+        :raises ValueError: if the name or description is blank, or the
+            version carries a prerelease or build component (unsupported in
+            pkg-config).
+        """
+        if self.name == "":
+            raise ValueError("unexpected blank name of pkg-config")
+        if self.description == "":
+            raise ValueError("unexpected blank description of pkg-config")
+        if self.version.prerelease is not None or self.version.build is not None:
+            raise ValueError(
+                "unsupported semantic version components (prerelease or build) in pkg-config"
+            )
 
 
 class PkgConfigRender:
+    """Renderer that turns :class:`PkgConfigProperties` into a ``.pc`` file.
+
+    Wraps a :class:`renders.common.BaseRender` and exposes :meth:`render` to
+    emit the package configuration file.
+    """
 
     __render: common.BaseRender
     __properties: PkgConfigProperties
 
     def __init__(self, properties: PkgConfigProperties) -> None:
+        """Create the renderer with its Jinja2 backend and bound properties.
+
+        :param properties: Validated inputs reused by :meth:`render`.
+        """
         self.__render = common.BaseRender()
         self.__properties = properties
 
     def render(self) -> str:
-        payload: dict[str, Any] = {}
+        """Render the ``<pkg>.pc`` file.
+
+        :returns: The rendered ``.pc`` content as a string.
+        """
+        payload: dict[str, Any] = {
+            "name": self.__properties.name,
+            "description": self.__properties.description,
+            "artifact": self.__properties.artifact,
+        }
         return self.__render.render("XXX.pc.jinja", payload)