POC for tool_requires that make direct dependees inherit generators

conan/internal/api/install/generators.py

@@ -73,6 +73,7 @@ def load_cache_generators(path):
 def write_generators(conanfile, app, envs_generation=None):
     new_gen_folder = conanfile.generators_folder
     _receive_conf(conanfile)
+    _receive_generators(conanfile)
 
     hook_manager = app.hook_manager
     # TODO: Optimize this, so the global generators are not loaded every call to write_generators
@@ -91,8 +92,11 @@ def write_generators(conanfile, app, envs_generation=None):
     conanfile.generators = []
     try:
         for generator_name in old_generators:
-            global_generator = global_generators.get(generator_name)
-            generator_class = global_generator or _get_generator_class(generator_name)
+            if isinstance(generator_name, str):
+                global_generator = global_generators.get(generator_name)
+                generator_class = global_generator or _get_generator_class(generator_name)
+            else:
+                generator_class = generator_name
             if generator_class:
                 try:
                     generator = generator_class(conanfile)
@@ -151,6 +155,13 @@ def _receive_conf(conanfile):
             conanfile.conf.compose_conf(build_require.conf_info)
 
 
+def _receive_generators(conanfile):
+    """  Collect generators_info from the immediate build_requires"""
+    for build_require in conanfile.dependencies.direct_build.values():
+        if build_require.generator_info:
+            conanfile.generators = build_require.generator_info + conanfile.generators
+
+
 def _generate_aggregated_env(conanfile):
 
     def deactivates(filenames):

conans/model/conan_file.py

@@ -74,6 +74,7 @@ class ConanFile:
     buildenv_info = None
     runenv_info = None
     conf_info = None
+    generator_info = None
 
     def __init__(self, display_name=""):
         self.display_name = display_name

conans/model/conanfile_interface.py

@@ -88,6 +88,10 @@ def context(self):
     def conf_info(self):
         return self._conanfile.conf_info
 
+    @property
+    def generator_info(self):
+        return self._conanfile.generator_info
+
     @property
     def dependencies(self):
         return self._conanfile.dependencies

test/integration/generators/test_generators_from_br.py

@@ -0,0 +1,31 @@
+import textwrap
+
+from conan.test.assets.genconanfile import GenConanfile
+from conan.test.utils.tools import TestClient
+
+
+def test_inject_generators_conf():
+    tc = TestClient(light=True)
+    tc.save({"tool/conanfile.py": textwrap.dedent("""
+    from conan import ConanFile
+
+    class MyGenerator:
+        def __init__(self, conanfile):
+            self.conanfile = conanfile
+
+        def generate(self):
+            self.conanfile.output.info("MyGenerator generated")
+
+    class ToolConan(ConanFile):
+        name = "tool"
+        version = "0.1"
+
+        def package_info(self):
+            self.generator_info = ["CMakeToolchain", MyGenerator]
+    """),
+             "conanfile.py": GenConanfile("app", "1.0").with_tool_requires("tool/0.1")})
+
+    tc.run("create tool")
+    tc.run("create .")
+    assert "app/1.0: CMakeToolchain generated: conan_toolchain.cmake" in tc.out
+    assert "app/1.0: MyGenerator generated" in tc.out