make CppInfo an importable tool (#14101)

* make CppInfo an importable tool

* load/save

conan/tools/__init__.py

@@ -0,0 +1,8 @@
+from conans.model.build_info import CppInfo as _CppInfo
+
+
+def CppInfo(conanfile):
+    # Creation of a CppInfo object, to decouple the creation from the actual internal location
+    # that at the moment doesn't require a ``conanfile`` argument, but might require in the future
+    # and allow us to refactor the location of conans.model.build_info import CppInfo
+    return _CppInfo()

conan/tools/gnu/autotoolsdeps.py

@@ -1,7 +1,7 @@
 from conan.internal import check_duplicated_generator
+from conan.tools import CppInfo
 from conan.tools.env import Environment
 from conan.tools.gnu.gnudeps_flags import GnuDepsFlags
-from conans.model.build_info import CppInfo
 
 
 class AutotoolsDeps:
@@ -18,7 +18,7 @@ def ordered_deps(self):
         return self._ordered_deps
 
     def _get_cpp_info(self):
-        ret = CppInfo()
+        ret = CppInfo(self._conanfile)
         for dep in self.ordered_deps:
             dep_cppinfo = dep.cpp_info.aggregated_components()
             # In case we have components, aggregate them, we do not support isolated

conan/tools/microsoft/nmakedeps.py

@@ -1,8 +1,8 @@
 import os
 
 from conan.internal import check_duplicated_generator
+from conan.tools import CppInfo
 from conan.tools.env import Environment
-from conans.model.build_info import CppInfo
 
 
 class NMakeDeps(object):
@@ -16,7 +16,7 @@ def __init__(self, conanfile):
 
     # TODO: This is similar from AutotoolsDeps: Refactor and make common
     def _get_cpp_info(self):
-        ret = CppInfo()
+        ret = CppInfo(self._conanfile)
         deps = self._conanfile.dependencies.host.topological_sort
         deps = [dep for dep in reversed(deps.values())]
         for dep in deps:

conans/model/build_info.py

@@ -1,9 +1,11 @@
 import copy
+import json
 import os
 from collections import OrderedDict, defaultdict
 
 from conan.api.output import ConanOutput
 from conans.errors import ConanException
+from conans.util.files import load, save
 
 _DIRS_VAR_NAMES = ["_includedirs", "_srcdirs", "_libdirs", "_resdirs", "_bindirs", "_builddirs",
                    "_frameworkdirs", "_objects"]
@@ -112,6 +114,35 @@ def serialize(self):
             "properties": self._properties
         }
 
+    @staticmethod
+    def deserialize(contents):
+        result = _Component()
+        # TODO: Refactor to avoid this repetition
+        fields = [
+            "includedirs",
+            "srcdirs",
+            "libdirs",
+            "resdirs",
+            "bindirs",
+            "builddirs",
+            "frameworkdirs",
+            "system_libs",
+            "frameworks",
+            "libs",
+            "defines",
+            "cflags",
+            "cxxflags",
+            "sharedlinkflags",
+            "exelinkflags",
+            "objects",
+            "sysroot",
+            "requires",
+            "properties"
+        ]
+        for f in fields:
+            setattr(result, f"_{f}", contents[f])
+        return result
+
     @property
     def includedirs(self):
         if self._includedirs is None:
@@ -420,6 +451,19 @@ def serialize(self):
             ret[component_name] = info.serialize()
         return ret
 
+    def deserialize(self, content):
+        self._package = _Component.deserialize(content.pop("root"))
+        for component_name, info in content.items():
+            self.components[component_name] = _Component.deserialize(info)
+        return self
+
+    def save(self, path):
+        save(path, json.dumps(self.serialize()))
+
+    def load(self, path):
+        content = json.loads(load(path))
+        return self.deserialize(content)
+
     @property
     def has_components(self):
         return len(self.components) > 0

conans/test/integration/conanfile/test_cpp_info_serialize.py

@@ -0,0 +1,40 @@
+import json
+import textwrap
+
+from conans.test.utils.tools import TestClient
+
+
+def test_cpp_info_serialize_round_trip():
+    """ test that serialize and deserialize CppInfo works
+    """
+    # TODO: Define standard name for file
+    c = TestClient()
+    conanfile = textwrap.dedent("""\
+        import os
+        from conan import ConanFile
+        from conan.tools import CppInfo
+
+        class Pkg(ConanFile):
+            name = "pkg"
+            version = "0.1"
+
+            def package(self):
+                cpp_info = CppInfo(self)
+                cpp_info.includedirs = ["myinc"]
+                cpp_info.libs = ["mylib", "myother"]
+                cpp_info.libdirs = ["mylibs"]
+                p = os.path.join(self.package_folder, "cpp_info.json")
+                cpp_info.save(p)
+
+            def package_info(self):
+                cpp_info = CppInfo(self).load("cpp_info.json")
+                self.cpp_info = cpp_info
+        """)
+
+    c.save({"conanfile.py": conanfile})
+    c.run("create . --format=json")
+    graph = json.loads(c.stdout)
+    cpp_info = graph["graph"]["nodes"]["1"]["cpp_info"]["root"]
+    assert cpp_info["includedirs"][0].endswith("myinc")
+    assert cpp_info["libdirs"][0].endswith("mylibs")
+    assert cpp_info["libs"] == ["mylib", "myother"]