Pass CMake Bin to Conan (#131)

Author: Behemyth

cppython/plugins/conan/builder.py

@@ -1,10 +1,11 @@
 """Construction of Conan data"""
 
+import shutil
 from pathlib import Path
 
 from pydantic import DirectoryPath
 
-from cppython.plugins.conan.schema import ConanDependency
+from cppython.plugins.conan.schema import ConanDependency, ConanfileGenerationData
 
 
 class Builder:
@@ -19,8 +20,16 @@ def _create_base_conanfile(
         base_file: Path,
         dependencies: list[ConanDependency],
         dependency_groups: dict[str, list[ConanDependency]],
+        cmake_binary: Path | None = None,
     ) -> None:
-        """Creates a conanfile_base.py with CPPython managed dependencies."""
+        """Creates a conanfile_base.py with CPPython managed dependencies.
+
+        Args:
+            base_file: Path to write the base conanfile
+            dependencies: List of main dependencies
+            dependency_groups: Dictionary of dependency groups (e.g., 'test')
+            cmake_binary: Optional path to CMake binary to use
+        """
         test_dependencies = dependency_groups.get('test', [])
 
         # Generate requirements method content
@@ -37,6 +46,16 @@ def _create_base_conanfile(
             '\n'.join(test_requires_lines) if test_requires_lines else '        pass  # No test requirements'
         )
 
+        # Generate configure method content for cmake_program if specified
+        if cmake_binary:
+            # Use forward slashes for cross-platform compatibility in Conan
+            cmake_path_str = str(cmake_binary.resolve()).replace('\\', '/')
+            configure_content = f'''    def configure(self):
+        """CPPython managed configuration."""
+        self.conf.define("tools.cmake:cmake_program", "{cmake_path_str}")'''
+        else:
+            configure_content = ''
+
         content = f'''"""CPPython managed base ConanFile.
 
 This file is auto-generated by CPPython. Do not edit manually.
@@ -48,6 +67,7 @@ def _create_base_conanfile(
 
 class CPPythonBase(ConanFile):
     """Base ConanFile with CPPython managed dependencies."""
+{configure_content}
 
     def requirements(self):
         """CPPython managed requirements."""
@@ -135,23 +155,36 @@ def export_sources(self):
     def generate_conanfile(
         self,
         directory: DirectoryPath,
-        dependencies: list[ConanDependency],
-        dependency_groups: dict[str, list[ConanDependency]],
-        name: str,
-        version: str,
+        data: ConanfileGenerationData,
     ) -> None:
         """Generate conanfile.py and conanfile_base.py for the project.
 
         Always generates the base conanfile with managed dependencies.
         Only creates conanfile.py if it doesn't exist (never modifies existing files).
+
+        Args:
+            directory: The project directory
+            data: Generation data containing dependencies, project info, and cmake binary path.
+                If cmake_binary is not provided, attempts to find cmake in the current
+                Python environment.
         """
         directory.mkdir(parents=True, exist_ok=True)
 
+        # Resolve cmake binary path
+        resolved_cmake: Path | None = None
+        if data.cmake_binary and data.cmake_binary != 'cmake':
+            resolved_cmake = Path(data.cmake_binary).resolve()
+        else:
+            # Try to find cmake in the current Python environment (venv)
+            cmake_path = shutil.which('cmake')
+            if cmake_path:
+                resolved_cmake = Path(cmake_path).resolve()
+
         # Always regenerate the base conanfile with managed dependencies
         base_file = directory / 'conanfile_base.py'
-        self._create_base_conanfile(base_file, dependencies, dependency_groups)
+        self._create_base_conanfile(base_file, data.dependencies, data.dependency_groups, resolved_cmake)
 
         # Only create conanfile.py if it doesn't exist
         conan_file = directory / self._filename
         if not conan_file.exists():
-            self._create_conanfile(conan_file, name, version)
+            self._create_conanfile(conan_file, data.name, data.version)

cppython/plugins/conan/plugin.py

@@ -20,7 +20,7 @@
 from cppython.plugins.cmake.schema import CMakeSyncData
 from cppython.plugins.conan.builder import Builder
 from cppython.plugins.conan.resolution import resolve_conan_data, resolve_conan_dependency
-from cppython.plugins.conan.schema import ConanData
+from cppython.plugins.conan.schema import ConanData, ConanfileGenerationData
 from cppython.utility.exception import NotSupportedError, ProviderInstallationError
 from cppython.utility.utility import TypeName
 
@@ -116,12 +116,17 @@ def _prepare_installation(self, groups: list[str] | None = None) -> Path:
                         for req in self.core_data.cppython_data.dependency_groups[group_name]
                     ]
 
+        generation_data = ConanfileGenerationData(
+            dependencies=resolved_dependencies,
+            dependency_groups=resolved_dependency_groups,
+            name=self.core_data.pep621_data.name,
+            version=self.core_data.pep621_data.version,
+            cmake_binary=self._cmake_binary,
+        )
+
         self.builder.generate_conanfile(
             self.core_data.project_data.project_root,
-            resolved_dependencies,
-            resolved_dependency_groups,
-            self.core_data.pep621_data.name,
-            self.core_data.pep621_data.version,
+            generation_data,
         )
 
         # Ensure build directory exists

cppython/plugins/conan/schema.py

@@ -297,6 +297,19 @@ class ConanData(CPPythonModel):
     profile_dir: Path
 
 
+class ConanfileGenerationData(CPPythonModel):
+    """Data required for generating conanfile.py and conanfile_base.py.
+
+    Groups related parameters for conanfile generation to reduce function argument count.
+    """
+
+    dependencies: list[ConanDependency]
+    dependency_groups: dict[str, list[ConanDependency]]
+    name: str
+    version: str
+    cmake_binary: str | None = None
+
+
 class ConanConfiguration(CPPythonModel):
     """Conan provider configuration"""
 

tests/unit/plugins/conan/test_builder.py

@@ -6,7 +6,7 @@
 import pytest
 
 from cppython.plugins.conan.builder import Builder
-from cppython.plugins.conan.schema import ConanDependency, ConanVersion
+from cppython.plugins.conan.schema import ConanDependency, ConanfileGenerationData, ConanVersion
 
 
 class TestBuilder:
@@ -44,13 +44,16 @@ def test_creates_both_files(self, builder: Builder, tmp_path: Path) -> None:
         ]
         dependency_groups = {}
 
-        builder.generate_conanfile(
-            directory=tmp_path,
+        data = ConanfileGenerationData(
             dependencies=dependencies,
             dependency_groups=dependency_groups,
             name='test-project',
             version='1.0.0',
         )
+        builder.generate_conanfile(
+            directory=tmp_path,
+            data=data,
+        )
 
         base_file = tmp_path / 'conanfile_base.py'
         conan_file = tmp_path / 'conanfile.py'
@@ -60,37 +63,43 @@ def test_creates_both_files(self, builder: Builder, tmp_path: Path) -> None:
 
     def test_regenerates_base_file(self, builder: Builder, tmp_path: Path) -> None:
         """Test base file is always regenerated with new dependencies."""
-        dependencies_v1 = [
+        initial_dependencies = [
             ConanDependency(name='boost', version=ConanVersion.from_string('1.80.0')),
         ]
 
-        builder.generate_conanfile(
-            directory=tmp_path,
-            dependencies=dependencies_v1,
+        initial_data = ConanfileGenerationData(
+            dependencies=initial_dependencies,
             dependency_groups={},
             name='test-project',
             version='1.0.0',
         )
+        builder.generate_conanfile(
+            directory=tmp_path,
+            data=initial_data,
+        )
 
         base_file = tmp_path / 'conanfile_base.py'
-        content_v1 = base_file.read_text(encoding='utf-8')
-        assert 'boost/1.80.0' in content_v1
+        initial_content = base_file.read_text(encoding='utf-8')
+        assert 'boost/1.80.0' in initial_content
 
-        dependencies_v2 = [
+        updated_dependencies = [
             ConanDependency(name='zlib', version=ConanVersion.from_string('1.2.13')),
         ]
 
-        builder.generate_conanfile(
-            directory=tmp_path,
-            dependencies=dependencies_v2,
+        updated_data = ConanfileGenerationData(
+            dependencies=updated_dependencies,
             dependency_groups={},
             name='test-project',
             version='1.0.0',
         )
+        builder.generate_conanfile(
+            directory=tmp_path,
+            data=updated_data,
+        )
 
-        content_v2 = base_file.read_text(encoding='utf-8')
-        assert 'zlib/1.2.13' in content_v2
-        assert 'boost/1.80.0' not in content_v2
+        updated_content = base_file.read_text(encoding='utf-8')
+        assert 'zlib/1.2.13' in updated_content
+        assert 'boost/1.80.0' not in updated_content
 
     def test_preserves_user_file(self, builder: Builder, tmp_path: Path) -> None:
         """Test user conanfile is never modified once created."""
@@ -112,13 +121,16 @@ def requirements(self):
             ConanDependency(name='boost', version=ConanVersion.from_string('1.80.0')),
         ]
 
-        builder.generate_conanfile(
-            directory=tmp_path,
+        data = ConanfileGenerationData(
             dependencies=dependencies,
             dependency_groups={},
             name='new-name',
             version='2.0.0',
         )
+        builder.generate_conanfile(
+            directory=tmp_path,
+            data=data,
+        )
 
         final_content = conan_file.read_text()
         assert final_content == custom_content
@@ -137,13 +149,16 @@ def test_inheritance_chain(self, builder: Builder, tmp_path: Path) -> None:
             ]
         }
 
-        builder.generate_conanfile(
-            directory=tmp_path,
+        data = ConanfileGenerationData(
             dependencies=dependencies,
             dependency_groups=dependency_groups,
             name='test-project',
             version='1.0.0',
         )
+        builder.generate_conanfile(
+            directory=tmp_path,
+            data=data,
+        )
 
         base_content = (tmp_path / 'conanfile_base.py').read_text(encoding='utf-8')
         user_content = (tmp_path / 'conanfile.py').read_text(encoding='utf-8')
@@ -156,3 +171,55 @@ def test_inheritance_chain(self, builder: Builder, tmp_path: Path) -> None:
         assert 'class TestProjectPackage(CPPythonBase):' in user_content
         assert 'super().requirements()' in user_content
         assert 'super().build_requirements()' in user_content
+
+    def test_cmake_binary_configure(self, builder: Builder, tmp_path: Path) -> None:
+        """Test that cmake_binary generates configure() with forward slashes."""
+        base_file = tmp_path / 'conanfile_base.py'
+        cmake_path = Path('C:/Program Files/CMake/bin/cmake.exe')
+
+        builder._create_base_conanfile(base_file, [], {}, cmake_binary=cmake_path)
+
+        content = base_file.read_text(encoding='utf-8')
+        assert 'def configure(self):' in content
+        assert 'self.conf.define("tools.cmake:cmake_program"' in content
+        assert 'C:/Program Files/CMake/bin/cmake.exe' in content
+        assert '\\' not in content.split('tools.cmake:cmake_program')[1].split('"')[1]
+
+    def test_no_cmake_binary(self, builder: Builder, tmp_path: Path) -> None:
+        """Test that no cmake_binary means no configure() method."""
+        base_file = tmp_path / 'conanfile_base.py'
+
+        builder._create_base_conanfile(base_file, [], {}, cmake_binary=None)
+
+        content = base_file.read_text(encoding='utf-8')
+        assert 'def configure(self):' not in content
+
+    @pytest.mark.parametrize(
+        ('venv_cmake', 'expect_configure'),
+        [
+            ('/path/to/venv/bin/cmake', True),
+            (None, False),
+        ],
+    )
+    def test_cmake_binary_venv_fallback(
+        self,
+        builder: Builder,
+        tmp_path: Path,
+        monkeypatch: pytest.MonkeyPatch,
+        venv_cmake: str | None,
+        expect_configure: bool,
+    ) -> None:
+        """Test venv cmake fallback when cmake_binary is default."""
+        monkeypatch.setattr('cppython.plugins.conan.builder.shutil.which', lambda _: venv_cmake)
+
+        data = ConanfileGenerationData(
+            dependencies=[],
+            dependency_groups={},
+            name='test-project',
+            version='1.0.0',
+            cmake_binary='cmake',
+        )
+        builder.generate_conanfile(directory=tmp_path, data=data)
+
+        content = (tmp_path / 'conanfile_base.py').read_text(encoding='utf-8')
+        assert ('def configure(self):' in content) == expect_configure