Prototype changes for multitree

This change contains a prototype implementation for multitree. Several
interfaces and modules are added.

1. Imported/Exported
Modules implementing Exportable interface can export artifacts to other
components. "imported_filegroup" modules can import generated artifacts from other exported modules.

2. Multitree metadata
It contains information about imported/exported modules in each
component, and can be generated via "m update-meta".

3. cc library stub
It's based on prototype stub libraries. It uses imported/exported
mechanism to expose a C API, with a map.txt file and header files.

Bug: 230448564
Test: m
Change-Id: Id7ff7618e2c630c5617a564d8b23b60a1cc9c8e8
diff --git a/cc/library_stub_test.go b/cc/library_stub_test.go
new file mode 100644
index 0000000..15b56d2
--- /dev/null
+++ b/cc/library_stub_test.go
@@ -0,0 +1,108 @@
+// Copyright 2021 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cc
+
+import (
+	_ "fmt"
+	_ "sort"
+
+	"testing"
+
+	"android/soong/android"
+	"android/soong/multitree"
+)
+
+func TestCcApiStubLibraryOutputFiles(t *testing.T) {
+	bp := `
+		cc_api_stub_library {
+			name: "foo",
+			symbol_file: "foo.map.txt",
+			first_version: "29",
+		}
+	`
+	result := prepareForCcTest.RunTestWithBp(t, bp)
+	outputs := result.ModuleForTests("foo", "android_arm64_armv8-a_shared").AllOutputs()
+	expected_file_suffixes := []string{".c", "stub.map", ".o", ".so"}
+	for _, expected_file_suffix := range expected_file_suffixes {
+		android.AssertBoolEquals(t, expected_file_suffix+" file not found in output", true, android.SuffixInList(outputs, expected_file_suffix))
+	}
+}
+
+func TestCcApiStubLibraryVariants(t *testing.T) {
+	bp := `
+		cc_api_stub_library {
+			name: "foo",
+			symbol_file: "foo.map.txt",
+			first_version: "29",
+		}
+	`
+	result := prepareForCcTest.RunTestWithBp(t, bp)
+	variants := result.ModuleVariantsForTests("foo")
+	expected_variants := []string{"29", "30", "S", "Tiramisu"} //TODO: make this test deterministic by using fixtures
+	for _, expected_variant := range expected_variants {
+		android.AssertBoolEquals(t, expected_variant+" variant not found in foo", true, android.SubstringInList(variants, expected_variant))
+	}
+}
+
+func TestCcLibraryUsesCcApiStubLibrary(t *testing.T) {
+	bp := `
+		cc_api_stub_library {
+			name: "foo",
+			symbol_file: "foo.map.txt",
+			first_version: "29",
+		}
+		cc_library {
+			name: "foo_user",
+			shared_libs: [
+				"foo#29",
+			],
+		}
+
+	`
+	prepareForCcTest.RunTestWithBp(t, bp)
+}
+
+func TestApiSurfaceOutputs(t *testing.T) {
+	bp := `
+		api_surface {
+			name: "mysdk",
+			contributions: [
+				"foo",
+			],
+		}
+
+		cc_api_contribution {
+			name: "foo",
+			symbol_file: "foo.map.txt",
+			first_version: "29",
+		}
+	`
+	result := android.GroupFixturePreparers(
+		prepareForCcTest,
+		multitree.PrepareForTestWithApiSurface,
+	).RunTestWithBp(t, bp)
+	mysdk := result.ModuleForTests("mysdk", "")
+
+	actual_surface_inputs := mysdk.Rule("phony").BuildParams.Inputs.Strings()
+	expected_file_suffixes := []string{"mysdk/foo/foo.map.txt"}
+	for _, expected_file_suffix := range expected_file_suffixes {
+		android.AssertBoolEquals(t, expected_file_suffix+" file not found in input", true, android.SuffixInList(actual_surface_inputs, expected_file_suffix))
+	}
+
+	// check args/inputs to rule
+	/*api_surface_gen_rule_args := result.ModuleForTests("mysdk", "").Rule("genApiSurfaceBuildFiles").Args
+	android.AssertStringEquals(t, "name", "foo.mysdk", api_surface_gen_rule_args["name"])
+	android.AssertStringEquals(t, "symbol_file", "foo.map.txt", api_surface_gen_rule_args["symbol_file"])*/
+}