java_sdk_library: Access outputs using tags

Previously, in order to access say the public stubs source jar it was
necessary to directly reference the module by name. This change adds
support for accessing them indirectly via tags.

Test: nothing
Bug: 155164730
Change-Id: Id6d76e56c7b46944b2d2a44a2163fb05a5b03de9

java/java_test.go

@@ -1230,6 +1230,113 @@ func TestJavaSdkLibrary(t *testing.T) {
 	}
 }
 
+func TestJavaSdkLibrary_UseSourcesFromAnotherSdkLibrary(t *testing.T) {
+	testJava(t, `
+		java_sdk_library {
+			name: "foo",
+			srcs: ["a.java"],
+			api_packages: ["foo"],
+			public: {
+				enabled: true,
+			},
+		}
+
+		java_library {
+			name: "bar",
+			srcs: ["b.java", ":foo{.public.stubs.source}"],
+		}
+		`)
+}
+
+func TestJavaSdkLibrary_AccessOutputFiles_MissingScope(t *testing.T) {
+	testJavaError(t, `"foo" does not provide api scope system`, `
+		java_sdk_library {
+			name: "foo",
+			srcs: ["a.java"],
+			api_packages: ["foo"],
+			public: {
+				enabled: true,
+			},
+		}
+
+		java_library {
+			name: "bar",
+			srcs: ["b.java", ":foo{.system.stubs.source}"],
+		}
+		`)
+}
+
+func TestJavaSdkLibraryImport_AccessOutputFiles(t *testing.T) {
+	testJava(t, `
+		java_sdk_library_import {
+			name: "foo",
+			public: {
+				jars: ["a.jar"],
+				stub_srcs: ["a.java"],
+				current_api: "api/current.txt",
+				removed_api: "api/removed.txt",
+			},
+		}
+
+		java_library {
+			name: "bar",
+			srcs: [":foo{.public.stubs.source}"],
+			java_resources: [
+				":foo{.public.api.txt}",
+				":foo{.public.removed-api.txt}",
+			],
+		}
+		`)
+}
+
+func TestJavaSdkLibraryImport_AccessOutputFiles_Invalid(t *testing.T) {
+	bp := `
+		java_sdk_library_import {
+			name: "foo",
+			public: {
+				jars: ["a.jar"],
+			},
+		}
+		`
+
+	t.Run("stubs.source", func(t *testing.T) {
+		testJavaError(t, `stubs.source not available for api scope public`, bp+`
+		java_library {
+			name: "bar",
+			srcs: [":foo{.public.stubs.source}"],
+			java_resources: [
+				":foo{.public.api.txt}",
+				":foo{.public.removed-api.txt}",
+			],
+		}
+		`)
+	})
+
+	t.Run("api.txt", func(t *testing.T) {
+		testJavaError(t, `api.txt not available for api scope public`, bp+`
+		java_library {
+			name: "bar",
+			srcs: ["a.java"],
+			java_resources: [
+				":foo{.public.api.txt}",
+			],
+		}
+		`)
+	})
+
+	t.Run("removed-api.txt", func(t *testing.T) {
+		testJavaError(t, `removed-api.txt not available for api scope public`, bp+`
+		java_library {
+			name: "bar",
+			srcs: ["a.java"],
+			java_resources: [
+				":foo{.public.removed-api.txt}",
+			],
+		}
+		`)
+	})
+}
+
 func TestJavaSdkLibrary_InvalidScopes(t *testing.T) {
 	testJavaError(t, `module "foo": enabled api scope "system" depends on disabled scope "public"`, `
 		java_sdk_library {