Add a way to specify link features in CMakeConfigDeps (#19444)

* initial sketch

* Some testing

* more links

* Last remaining link feature for interface libraries

* Integreation tests

* Add functional test with custom link feature

* cleanup

* Add version check

* Update conan/tools/cmake/cmakeconfigdeps/target_configuration.py

Co-authored-by: James <[email protected]>

* Update conan/tools/cmake/cmakeconfigdeps/target_configuration.py

Co-authored-by: James <[email protected]>

---------

Co-authored-by: James <[email protected]>

Author: AbrilRBS

conan/tools/cmake/cmakeconfigdeps/target_configuration.py

@@ -57,8 +57,12 @@ def _requires(self, info, components):
                     continue
                 dep_target = self._cmakedeps.get_property("cmake_target_name", d)
                 dep_target = dep_target or f"{d.ref.name}::{d.ref.name}"
+                link_feature = self._cmakedeps.get_property("cmake_link_feature", d)
                 link = not (pkg_type is PackageType.SHARED and d.package_type is PackageType.SHARED)
-                result[dep_target] = link
+                result[dep_target] = {
+                    "link": link,
+                    "link_feature": link_feature
+                }
             return result
 
         for required_pkg, required_comp in requires:
@@ -70,7 +74,12 @@ def _requires(self, info, components):
                 dep_target = dep_target or f"{pkg_name}::{required_comp}"
                 link = not (pkg_type is PackageType.SHARED and
                             dep_comp.type is PackageType.SHARED)
-                result[dep_target] = link
+                link_feature = self._cmakedeps.get_property("cmake_link_feature", self._conanfile,
+                                                              required_comp)
+                result[dep_target] = {
+                    "link": link,
+                    "link_feature": link_feature
+                }
             else:  # Different package
                 try:
                     dep = transitive_reqs[required_pkg]
@@ -102,8 +111,12 @@ def _requires(self, info, components):
 
                     dep_target = self._cmakedeps.get_property("cmake_target_name", dep, comp)
                     dep_target = dep_target or default_target
+                    link_feature = self._cmakedeps.get_property("cmake_link_feature", dep, comp)
 
-                    result[dep_target] = link
+                    result[dep_target] = {
+                        "link": link,
+                        "link_feature": link_feature
+                    }
         return result
 
     @property
@@ -195,6 +208,7 @@ def _get_cmake_lib(self, info, components, pkg_folder, pkg_folder_var, comp_name
                                                   comp_name=comp_name, check_type=list) or []
         sources = [self._path(source, pkg_folder, pkg_folder_var) for source in info.sources]
         target = {"type": "INTERFACE",
+                  "comp_name": comp_name,
                   "includedirs": includedirs,
                   "defines": defines,
                   "requires": requires,
@@ -264,9 +278,19 @@ def _add_root_lib_target(self, libs, pkg_name, cpp_info):
                     target_name = self._cmakedeps.get_property("cmake_target_name", self._conanfile,
                                                                defaultc)
                     comp_name = target_name or f"{pkg_name}::{defaultc}"
-                    all_requires[comp_name] = True  # It is an interface, full link
+                    link_feature = self._cmakedeps.get_property("cmake_link_feature", self._conanfile,
+                                                                defaultc)
+                    all_requires[comp_name] = {
+                        "link": True,  # It is an interface, full link
+                        "link_feature": link_feature
+                    }
             else:
-                all_requires = {k: True for k in libs.keys()}
+                all_requires = {k: {
+                    "link": True,
+                    "link_feature": self._cmakedeps.get_property("cmake_link_feature", self._conanfile,
+                                                                 v.get("comp_name"))
+                }
+                    for k, v in libs.items()}
             # This target might have an alias, so we need to check it
             cmake_target_aliases = self._get_aliases()
             libs[root_target_name] = {"type": "INTERFACE",
@@ -407,16 +431,26 @@ def _template(self):
 
         {% if lib_info.get("requires") %}
         # Information of transitive dependencies
-        {% for require_target, link in lib_info["requires"].items() %}
-        # Requirement {{require_target}} => Full link: {{link}}
+        {% for require_target, link_info in lib_info["requires"].items() %}
 
-        {% if link %}
+        # Requirement {{lib}} -> {{require_target}} (Full link: {{link_info["link"]}})
+        {% if link_info["link"] %}
+        {% if link_info["link_feature"] %}
+        # Link feature: {{link_info["link_feature"]}}
+        if(CMAKE_VERSION VERSION_LESS "3.24")
+            message(FATAL_ERROR "The 'CMakeConfigDeps' generator LINK_FEATURE property only works with CMake >= 3.24")
+        endif()
+        {% endif %}
         # set property allows to append, and lib_info[requires] will iterate
         set_property(TARGET {{lib}} APPEND PROPERTY INTERFACE_LINK_LIBRARIES
+            {% if link_info["link_feature"] %}
+                     "$<LINK_LIBRARY:{{link_info["link_feature"]}},{{config_wrapper(config, require_target)}}>")
+            {% else %}
                      "{{config_wrapper(config, require_target)}}")
+            {% endif %}
         {% else %}
-        if(${CMAKE_VERSION} VERSION_LESS "3.27")
-            message(FATAL_ERROR "The 'CMakeToolchain' generator only works with CMake >= 3.27")
+        if(CMAKE_VERSION VERSION_LESS "3.27")
+            message(FATAL_ERROR "The 'CMakeConfigDeps' generator COMPILE_ONLY expression only works with CMake >= 3.27")
         endif()
         # If the headers trait is not there, this will do nothing
         target_link_libraries({{lib}} INTERFACE

test/functional/toolchains/cmake/cmakedeps2/test_cmakeconfigdeps_new.py

@@ -402,6 +402,28 @@ def test_transitive_headers(self, shared):
         c.run(f"build . -o *:shared={shared} -c tools.cmake.cmakedeps:new={new_value}")
         # it works
 
+    @pytest.mark.tool("cmake", "3.27")
+    def test_link_features(self):
+        tc = TestClient()
+        tc.run("new cmake_lib -d name=matrix -d version=0.1")
+        conanfile = tc.load("conanfile.py")
+        # So that the custom link feature works
+        conanfile += ("        self.cpp_info.set_property('cmake_extra_variables', "
+                      "{'CMAKE_LINK_LIBRARY_USING_MYFET_SUPPORTED': True,"
+                      "'CMAKE_LINK_LIBRARY_USING_MYFET': '<LIBRARY>'})\n")
+        # And set this library to use the custom link feature
+        conanfile += "        self.cpp_info.set_property('cmake_link_feature', 'MYFET')"
+        tc.save({"conanfile.py": conanfile})
+        tc.run(f"create -c tools.cmake.cmakedeps:new={new_value}")
+
+        tc.save({}, clean_first=True)
+        tc.run("new cmake_lib -d name=lib -d version=0.1 -d requires=matrix/0.1")
+        tc.run(f"create -c tools.cmake.cmakedeps:new={new_value}")
+        test_build_folder = tc.created_test_build_folder("lib/0.1")
+        test_generators_folder = os.path.join("test_package", test_build_folder, "generators")
+        libs_targets = tc.load(os.path.join(test_generators_folder, "lib-Targets-release.cmake"))
+        assert '"$<LINK_LIBRARY:MYFET,$<$<CONFIG:RELEASE>:matrix::matrix>>"' in libs_targets
+
 
 @pytest.mark.tool("cmake")
 class TestLibsComponents:

test/integration/toolchains/cmake/cmakedeps2/test_cmakedeps.py

@@ -495,7 +495,7 @@ def package_info(self):
         targets = c.load("libtool-Targets-release.cmake")
         # The libtool shouldn't depend on the automake::automake target
         assert "automake::automake" not in targets
-        assert "# Requirement automake::mylibapp => Full link: True" in targets
+        assert "# Requirement libtool::libtool -> automake::mylibapp (Full link: True)" in targets
         assert "$<$<CONFIG:RELEASE>:automake::mylibapp>" in targets
 
     def test_requires_from_library_component(self):
@@ -656,4 +656,112 @@ def package_info(self):
     client.run(f"install --requires=pkg/0.1 -g CMakeDeps -c tools.cmake.cmakedeps:new={new_value}")
     target = client.load("pkg-Targets-release.cmake")
     assert 'add_library(pkg::base INTERFACE IMPORTED)' in target
-    assert "# Requirement pkg::base => Full link: True" in target
+    assert "# Requirement pkg::comp -> pkg::base (Full link: True)" in target
+
+
+class TestLinkFeatures:
+    def test_link_info_global_cpp_info(self):
+        tc = TestClient()
+        conanfile = textwrap.dedent("""
+        from conan import ConanFile
+
+        class Pkg(ConanFile):
+            name = "pkg"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+
+            def package_info(self):
+                self.cpp_info.set_property("cmake_link_feature", "MYFET")
+        """)
+        tc.save({"conanfile.py": conanfile})
+        tc.run("create")
+
+        dep = textwrap.dedent("""
+        from conan import ConanFile
+        class Dep(ConanFile):
+            name = "dep"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+            requires = "pkg/1.0"
+        """)
+        tc.save({"conanfile.py": dep})
+        tc.run("create")
+        tc.run("install --requires=dep/1.0 -g CMakeConfigDeps")
+        # The requirement should propagate the link feature info
+        target = tc.load("dep-Targets-release.cmake")
+        assert "# Requirement dep::dep -> pkg::pkg (Full link: True)\n# Link feature: MYFET" in target
+
+    def test_link_info_local_component_from_interface(self):
+        tc = TestClient()
+        conanfile = textwrap.dedent("""
+        from conan import ConanFile
+
+        class Pkg(ConanFile):
+            name = "pkg"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+
+            def package_info(self):
+                self.cpp_info.components["compA"].set_property("cmake_link_feature", "MYFET")
+        """)
+        tc.save({"conanfile.py": conanfile})
+        tc.run("create")
+        tc.run("install --requires=pkg/1.0 -g CMakeConfigDeps")
+        targets = tc.load("pkg-Targets-release.cmake")
+        # The interface library created as a global target should have the requirement
+        assert "# Requirement pkg::pkg -> pkg::compA (Full link: True)\n# Link feature: MYFET" in targets
+
+    def test_link_info_local_component_to_component_require(self):
+        tc = TestClient()
+        conanfile = textwrap.dedent("""
+        from conan import ConanFile
+
+        class Pkg(ConanFile):
+            name = "pkg"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+
+            def package_info(self):
+                self.cpp_info.components["compA"].set_property("cmake_link_feature", "MYFET")
+                self.cpp_info.components["compB"].requires = ["compA"]
+        """)
+        tc.save({"conanfile.py": conanfile})
+        tc.run("create")
+        tc.run("install --requires=pkg/1.0 -g CMakeConfigDeps")
+        targets = tc.load("pkg-Targets-release.cmake")
+        # The component requirement should have the link feature info
+        assert "# Requirement pkg::compB -> pkg::compA (Full link: True)\n# Link feature: MYFET" in targets
+
+    def test_link_info_lib_to_component_require(self):
+        tc = TestClient()
+        conanfile = textwrap.dedent("""
+        from conan import ConanFile
+
+        class Pkg(ConanFile):
+            name = "pkg"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+
+            def package_info(self):
+                self.cpp_info.components["compA"].set_property("cmake_link_feature", "MYFET")
+        """)
+        tc.save({"conanfile.py": conanfile})
+        tc.run("create")
+
+        dep = textwrap.dedent("""
+        from conan import ConanFile
+        class Dep(ConanFile):
+            name = "dep"
+            version = "1.0"
+            settings = "os", "compiler", "build_type", "arch"
+            requires = "pkg/1.0"
+
+            def package_info(self):
+                self.cpp_info.requires = ["pkg::compA"]
+        """)
+        tc.save({"conanfile.py": dep})
+        tc.run("create")
+        tc.run("install --requires=dep/1.0 -g CMakeConfigDeps")
+        targets = tc.load("dep-Targets-release.cmake")
+        # The requirement should have the link feature info
+        assert "# Requirement dep::dep -> pkg::compA (Full link: True)\n# Link feature: MYFET" in targets