Feature/language cppstd

conan/tools/cmake/cmakedeps/templates/target_configuration.py

@@ -29,14 +29,18 @@ def context(self):
         is_win = self.conanfile.settings.get_safe("os") == "Windows"
         auto_link = self.cmakedeps.get_property("cmake_set_interface_link_directories",
                                                 self.conanfile, check_type=bool)
+        link_languages = [lang if lang != "C++" else "CXX" for lang in self.conanfile.languages]
+        link_languages = ";".join(link_languages)
+
         return {"pkg_name": self.pkg_name,
                 "root_target_name": self.root_target_name,
                 "config_suffix": self.config_suffix,
                 "config": self.configuration.upper(),
                 "deps_targets_names": ";".join(deps_targets_names),
                 "components_names": components_names,
                 "configuration": self.cmakedeps.configuration,
-                "set_interface_link_directories": auto_link and is_win}
+                "set_interface_link_directories": auto_link and is_win,
+                "link_languages": None}
 
     @property
     def template(self):
@@ -128,6 +132,9 @@ def template(self):
                          $<$<CONFIG:{{configuration}}>:{{ pkg_var(pkg_name, 'LIB_DIRS', config_suffix) }}>)
             {%- endif %}
 
+            {% if link_languages %}
+            set_target_properties({{root_target_name}} PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "{{link_languages}}")
+            {%- endif %}
 
         {%- else %}
 

test/functional/toolchains/cmake/cmakedeps/test_auto_stdcpp.py

@@ -0,0 +1,48 @@
+import textwrap
+
+
+def test_auto_cppstd(matrix_c_interface_client):
+    c = matrix_c_interface_client
+
+    consumer = textwrap.dedent("""
+        cmake_minimum_required(VERSION 3.15)
+        project(myapp C)
+
+        find_package(matrix REQUIRED)
+
+        add_executable(app app.c)
+        target_link_libraries(app PRIVATE matrix::matrix)
+        """)
+
+    conanfile = textwrap.dedent("""\
+        import os
+        from conan import ConanFile
+        from conan.tools.cmake import CMake, cmake_layout
+
+        class Recipe(ConanFile):
+            settings = "os", "compiler", "build_type", "arch"
+            package_type = "application"
+            generators = "CMakeToolchain", "CMakeDeps"
+            requires = "matrix/0.1"
+
+            def layout(self):
+                cmake_layout(self)
+
+            def build(self):
+                cmake = CMake(self)
+                cmake.configure()
+                cmake.build()
+                self.run(os.path.join(self.cpp.build.bindir, "app"), env="conanrun")
+        """)
+    app = textwrap.dedent("""
+        #include "matrix.h"
+        int main(){
+            matrix();
+            return 0;
+        }
+        """)
+    c.save({"conanfile.py": conanfile,
+            "CMakeLists.txt": consumer,
+            "app.c": app}, clean_first=True)
+    c.run("build .")
+    assert "Hello Matrix!" in c.out

test/functional/toolchains/conftest.py

@@ -1,5 +1,6 @@
 import os
 import shutil
+import textwrap
 
 import pytest
 
@@ -48,3 +49,91 @@ def transitive_libraries(_transitive_libraries):
     c.cache_folder = os.path.join(temp_folder(), ".conan2")
     shutil.copytree(_transitive_libraries.cache_folder, c.cache_folder)
     return c
+
+
+@pytest.fixture(scope="session")
+def _matrix_c_interface_client():
+    c = TestClient()
+    matrix_h = textwrap.dedent("""\
+        #pragma once
+        #ifdef __cplusplus
+        extern "C" {
+        #endif
+            void matrix();
+        #ifdef __cplusplus
+        }
+        #endif
+        """)
+    matrix_cpp = textwrap.dedent("""\
+        #include "matrix.h"
+        #include <iostream>
+        #include <string>
+
+        void matrix(){
+            std::cout<< std::string("Hello Matrix!") <<std::endl;
+        }
+        """)
+    cmake = textwrap.dedent("""\
+        cmake_minimum_required(VERSION 3.15)
+        project(matrix C CXX)
+        add_library(matrix STATIC src/matrix.cpp)
+        target_include_directories(matrix PUBLIC
+          $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+          $<INSTALL_INTERFACE:include>
+        )
+        set_target_properties(matrix PROPERTIES PUBLIC_HEADER "include/matrix.h")
+
+        install(TARGETS matrix EXPORT matrixConfig)
+        export(TARGETS matrix
+            NAMESPACE matrix::
+            FILE "${CMAKE_CURRENT_BINARY_DIR}/matrixConfig.cmake"
+        )
+
+        install(EXPORT matrixConfig
+            DESTINATION "${CMAKE_INSTALL_PREFIX}/matrix/cmake"
+            NAMESPACE matrix::
+        )
+        """)
+    conanfile = textwrap.dedent("""\
+        from conan import ConanFile
+        from conan.tools.cmake import CMake, cmake_layout
+
+        class Recipe(ConanFile):
+            name = "matrix"
+            version = "0.1"
+            settings = "os", "compiler", "build_type", "arch"
+            package_type = "static-library"
+            generators = "CMakeToolchain"
+            exports_sources = "CMakeLists.txt", "src/*", "include/*"
+
+            languages = "C", "C++"
+
+            def build(self):
+                cmake = CMake(self)
+                cmake.configure()
+                cmake.build()
+
+            def layout(self):
+                cmake_layout(self)
+
+            def package(self):
+                cmake = CMake(self)
+                cmake.install()
+
+            def package_info(self):
+                self.cpp_info.libs = ["matrix"]
+        """)
+    c.save({"include/matrix.h": matrix_h,
+            "src/matrix.cpp": matrix_cpp,
+            "conanfile.py": conanfile,
+            "CMakeLists.txt": cmake})
+    c.run("create .")
+    return c
+
+
+@pytest.fixture()
+def matrix_c_interface_client(_matrix_c_interface_client):
+    c = TestClient()
+    c.cache_folder = os.path.join(temp_folder(), ".conan2")
+    shutil.copytree(_matrix_c_interface_client.cache_folder, c.cache_folder)
+    return c

test/integration/package_id/test_cache_compatibles.py

@@ -316,7 +316,8 @@ def package_info(self):
         assert "pkg/0.1: CPPSTD: 17" in c.out
 
     def test_check_min_cstd(self):
-        """ test that the check_min_cstd works fine with compatibility
+        """
+        test that the check_min_cstd works fine with compatibility
         """
         conanfile = textwrap.dedent("""
             from conan import ConanFile