Feature: set CMAKE_FIND_PACKAGE_PREFER_CONFIG=ON (#8599)

* - set CMAKE_FIND_PACKAGE_PREFER_CONFIG=ON

Signed-off-by: SSE4 <tomskside@gmail.com>

* - add conf & test

Signed-off-by: SSE4 <tomskside@gmail.com>

* - remove some debug code

Signed-off-by: SSE4 <tomskside@gmail.com>

* - fix file name for config

Signed-off-by: SSE4 <tomskside@gmail.com>

* Update base.py

* Update base.py

conan/tools/cmake/base.py

@@ -95,6 +95,9 @@ class CMakeToolchainBase(object):
             # We are going to adjust automagically many things as requested by Conan
             #   these are the things done by 'conan_basic_setup()'
             set(CMAKE_EXPORT_NO_PACKAGE_REGISTRY ON)
+            {%- if find_package_prefer_config %}
+            set(CMAKE_FIND_PACKAGE_PREFER_CONFIG {{ find_package_prefer_config }})
+            {%- endif %}
             # To support the cmake_find_package generators
             {% if cmake_module_path -%}
             set(CMAKE_MODULE_PATH {{ cmake_module_path }} ${CMAKE_MODULE_PATH})
@@ -143,6 +146,8 @@ class CMakeToolchainBase(object):
         """)
 
     def __init__(self, conanfile, **kwargs):
+        import six
+
         self._conanfile = conanfile
         self.variables = Variables()
         self.preprocessor_definitions = Variables()
@@ -153,6 +158,12 @@ def __init__(self, conanfile, **kwargs):
 
         self.build_type = None
 
+        self.find_package_prefer_config = \
+            conanfile.conf["tools.cmake.cmaketoolchain"].find_package_prefer_config
+        if self.find_package_prefer_config is not None:
+            self.find_package_prefer_config = "OFF" if self.find_package_prefer_config.lower() in ("false", "0", "off") else "ON"
+        else:
+            self.find_package_prefer_config = "ON"  # assume ON by default if not specified in conf
     def _get_templates(self):
         return {
             'toolchain_macros': self._toolchain_macros_tpl,
@@ -172,6 +183,7 @@ def _get_template_context_data(self):
             "cmake_prefix_path": self.cmake_prefix_path,
             "cmake_module_path": self.cmake_module_path,
             "build_type": self.build_type,
+            "find_package_prefer_config": self.find_package_prefer_config,
         }
         return ctxt_toolchain
 

conans/test/functional/toolchains/cmake/test_cmake.py

@@ -530,3 +530,59 @@ def build(self):
         client.run("install .")
         client.run("build .")
         self.assertIn("VALUE OF CONFIG STRING: my new value", client.out)
+
+
+@pytest.mark.toolchain
+@pytest.mark.tool_cmake
+class CMakeFindPackagePreferConfigTest(unittest.TestCase):
+
+    @parameterized.expand([(True,), (False,)])
+    def test_prefer_config(self, prefer_config):
+        conanfile = textwrap.dedent("""
+            from conans import ConanFile
+            from conan.tools.cmake import CMake, CMakeToolchain
+            class App(ConanFile):
+                settings = "os", "arch", "compiler", "build_type"
+                exports_sources = "CMakeLists.txt"
+                def generate(self):
+                    toolchain = CMakeToolchain(self)
+                    toolchain.generate()
+                def build(self):
+                    cmake = CMake(self)
+                    cmake.configure()
+        """)
+
+        cmakelist = textwrap.dedent("""
+            cmake_minimum_required(VERSION 3.15)
+            project(my_project)
+            find_package(Comandante REQUIRED)
+        """)
+
+        find = textwrap.dedent("""
+            message(STATUS "using FindComandante.cmake")
+        """)
+
+        config = textwrap.dedent("""
+            message(STATUS "using ComandanteConfig.cmake")
+        """)
+
+        profile = textwrap.dedent("""
+            include(default)
+            [conf]
+            tools.cmake.cmaketoolchain:find_package_prefer_config={}
+        """).format(prefer_config)
+
+        client = TestClient()
+        client.save({"conanfile.py": conanfile,
+                     "CMakeLists.txt": cmakelist,
+                     "FindComandante.cmake": find,
+                     "ComandanteConfig.cmake": config,
+                     "profile": profile})
+
+        client.run("install . --profile profile")
+        client.run("build .")
+
+        if prefer_config:
+            self.assertIn("using ComandanteConfig.cmake", client.out)
+        else:
+            self.assertIn("using FindComandante.cmake", client.out)