check-flagged-apis: add list subcommand

Add a new subcommand to list all flagged APIs and corresponding flags.
This provides an overview of what flagged APIs exist in the Android
tree.

Bug: 345207706
Test: build/tools/check-flagged-apis/check-flagged-apis.sh list
Test: atest check-flagged-apis-test
Flag: EXEMPT host side tool
Change-Id: Icc224f3787480353baabbd3946f36f003f35db59

tools/check-flagged-apis/check-flagged-apis.sh

@@ -14,8 +14,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Run check-flagged-apis for public APIs and the three @SystemApi flavours
+# Run check-flagged-apis for public APIs and the three @SystemApi flavours.
-# Usage: lunch <your-target> && source <this script>
+#
+# This script expects an argument to tell it which subcommand of
+# check-flagged-apis to execute. Run the script without any arguments to see
+# the valid options.
+#
+# Remember to lunch to select the relevant release config before running this script.
 
 source $(cd $(dirname $BASH_SOURCE) &> /dev/null && pwd)/../../shell_utils.sh
 require_top
@@ -43,6 +48,10 @@ function build() {
         $MODULE_LIB_XML_VERSIONS
 }
 
+function noop() {
+    true
+}
+
 function aninja() {
     local T="$(gettop)"
     (\cd "${T}" && prebuilts/build-tools/linux-x86/bin/ninja -f out/combined-${TARGET_PRODUCT}.ninja "$@")
@@ -52,7 +61,7 @@ function path_to_api_signature_file {
     aninja -t query device_"$1"_all_targets | grep -A1 -e input: | tail -n1
 }
 
-function run() {
+function run_check() {
     local errors=0
 
     echo "# current"
@@ -89,8 +98,39 @@ function run() {
     return $errors
 }
 
-if [[ "$1" != "--skip-build" ]]; then
+function run_list() {
-    build && run
+    echo "# current"
-else
+    check-flagged-apis list \
-    run
+        --api-signature $(path_to_api_signature_file "frameworks-base-api-current.txt") \
+        --flag-values $(gettop)/out/soong/.intermediates/all_aconfig_declarations.pb
+
+    echo
+    echo "# system-current"
+    check-flagged-apis list \
+        --api-signature $(path_to_api_signature_file "frameworks-base-api-system-current.txt") \
+        --flag-values $(gettop)/out/soong/.intermediates/all_aconfig_declarations.pb
+
+    echo
+    echo "# system-server-current"
+    check-flagged-apis list \
+        --api-signature $(path_to_api_signature_file "frameworks-base-api-system-server-current.txt") \
+        --flag-values $(gettop)/out/soong/.intermediates/all_aconfig_declarations.pb
+
+    echo
+    echo "# module-lib"
+    check-flagged-apis list \
+        --api-signature $(path_to_api_signature_file "frameworks-base-api-module-lib-current.txt") \
+        --flag-values $(gettop)/out/soong/.intermediates/all_aconfig_declarations.pb
+}
+
+build_cmd=build
+if [[ "$1" == "--skip-build" ]]; then
+    build_cmd=noop
+    shift 1
 fi
+
+case "$1" in
+    check) $build_cmd && run_check ;;
+    list) $build_cmd && run_list ;;
+    *) echo "usage: $(basename $0): [--skip-build] check|list"; exit 1
+esac

tools/check-flagged-apis/src/com/android/checkflaggedapis/CheckFlaggedApisTest.kt

@@ -358,4 +358,23 @@ class CheckFlaggedApisTest {
             parseApiVersions(API_VERSIONS.byteInputStream()))
     assertEquals(expected, actual)
   }
+
+  @Test
+  fun testListFlaggedApis() {
+    val expected =
+        listOf(
+            "android.flag.bar DISABLED android/Clazz/Builder",
+            "android.flag.foo ENABLED android/Clazz",
+            "android.flag.foo ENABLED android/Clazz/Clazz()",
+            "android.flag.foo ENABLED android/Clazz/FOO",
+            "android.flag.foo ENABLED android/Clazz/getErrorCode()",
+            "android.flag.foo ENABLED android/Clazz/innerClassArg(Landroid/Clazz/Builder;)",
+            "android.flag.foo ENABLED android/Clazz/setData(I[[ILandroid/util/Utility;)",
+            "android.flag.foo ENABLED android/Clazz/setVariableData(I[Landroid/util/Atom;)")
+    val actual =
+        listFlaggedApis(
+            parseApiSignature("in-memory", API_SIGNATURE.byteInputStream()),
+            parseFlagValues(generateFlagsProto(ENABLED, DISABLED)))
+    assertEquals(expected, actual)
+  }
 }

tools/check-flagged-apis/src/com/android/checkflaggedapis/Main.kt

@@ -210,6 +210,40 @@ The tool will exit with a non-zero exit code if any flagged APIs are found to be
   }
 }
 
+class ListCommand :
+    CliktCommand(
+        help =
+            """
+List all flagged APIs and corresponding flags.
+
+The output format is "<fully-qualified-name-of-flag> <state-of-flag> <API>", one line per API.
+
+The output can be post-processed by e.g. piping it to grep to filter out only enabled APIs, or all APIs guarded by a given flag.
+""") {
+  private val apiSignaturePath by
+      option(ARG_API_SIGNATURE)
+          .help(ARG_API_SIGNATURE_HELP)
+          .path(mustExist = true, canBeDir = false, mustBeReadable = true)
+          .required()
+  private val flagValuesPath by
+      option(ARG_FLAG_VALUES)
+          .help(ARG_FLAG_VALUES_HELP)
+          .path(mustExist = true, canBeDir = false, mustBeReadable = true)
+          .required()
+
+  override fun run() {
+    val flaggedSymbols =
+        apiSignaturePath.toFile().inputStream().use {
+          parseApiSignature(apiSignaturePath.toString(), it)
+        }
+    val flags = flagValuesPath.toFile().inputStream().use { parseFlagValues(it) }
+    val output = listFlaggedApis(flaggedSymbols, flags)
+    if (output.isNotEmpty()) {
+      println(output.joinToString("\n"))
+    }
+  }
+}
+
 internal fun parseApiSignature(path: String, input: InputStream): Set<Pair<Symbol, Flag>> {
   val output = mutableSetOf<Pair<Symbol, Flag>>()
   val visitor =
@@ -460,4 +494,35 @@ internal fun findErrors(
   return errors
 }
 
-fun main(args: Array<String>) = MainCommand().subcommands(CheckCommand()).main(args)
+/**
+ * Collect all known info about all @FlaggedApi annotated APIs.
+ *
+ * Each API will be represented as a String, on the format
+ * <pre>
+ *   &lt;fully-qualified-name-of-flag&lt; &lt;state-of-flag&lt; &lt;API&lt;
+ * </pre>
+ *
+ * @param flaggedSymbolsInSource the set of symbols that are flagged in the source code
+ * @param flags the set of flags and their values
+ * @return a list of Strings encoding API data using the format described above, sorted
+ *   alphabetically
+ */
+internal fun listFlaggedApis(
+    flaggedSymbolsInSource: Set<Pair<Symbol, Flag>>,
+    flags: Map<Flag, Boolean>
+): List<String> {
+  val output = mutableListOf<String>()
+  for ((symbol, flag) in flaggedSymbolsInSource) {
+    val flagState =
+        when (flags.get(flag)) {
+          true -> "ENABLED"
+          false -> "DISABLED"
+          null -> "UNKNOWN"
+        }
+    output.add("$flag $flagState ${symbol.toPrettyString()}")
+  }
+  output.sort()
+  return output
+}
+
+fun main(args: Array<String>) = MainCommand().subcommands(CheckCommand(), ListCommand()).main(args)