Merge "Replace --revert-annotation with a flags config file" into main
diff --git a/apex/apex_test.go b/apex/apex_test.go
index a0a42a1..36a6974 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -11667,7 +11667,7 @@
 
 	// Arguments passed to aconfig to retrieve the state of the flags defined in the
 	// textproto files
-	aconfigFlagArgs := m.Output("released-flagged-apis-exportable.txt").Args["flags_path"]
+	aconfigFlagArgs := m.Output("released-flags-exportable.pb").Args["flags_path"]
 
 	// "bar-lib" is a static_lib of "foo" and is passed to metalava as classpath. Thus the
 	// cache file provided by the associated aconfig_declarations module "bar" should be passed
diff --git a/java/builder.go b/java/builder.go
index ade9784..dff0032 100644
--- a/java/builder.go
+++ b/java/builder.go
@@ -310,7 +310,7 @@
 
 	gatherReleasedFlaggedApisRule = pctx.AndroidStaticRule("gatherReleasedFlaggedApisRule",
 		blueprint.RuleParams{
-			Command: `${aconfig} dump-cache --dedup --format='{fully_qualified_name}' ` +
+			Command: `${aconfig} dump-cache --dedup --format=protobuf ` +
 				`--out ${out} ` +
 				`${flags_path} ` +
 				`${filter_args} `,
@@ -320,8 +320,8 @@
 
 	generateMetalavaRevertAnnotationsRule = pctx.AndroidStaticRule("generateMetalavaRevertAnnotationsRule",
 		blueprint.RuleParams{
-			Command:     `${keep-flagged-apis} ${in} > ${out}`,
-			CommandDeps: []string{"${keep-flagged-apis}"},
+			Command:     `${aconfig-to-metalava-flags} ${in} > ${out}`,
+			CommandDeps: []string{"${aconfig-to-metalava-flags}"},
 		})
 
 	generateApiXMLRule = pctx.AndroidStaticRule("generateApiXMLRule",
@@ -339,7 +339,7 @@
 	pctx.HostBinToolVariable("aconfig", "aconfig")
 	pctx.HostBinToolVariable("ravenizer", "ravenizer")
 	pctx.HostBinToolVariable("apimapper", "apimapper")
-	pctx.HostBinToolVariable("keep-flagged-apis", "keep-flagged-apis")
+	pctx.HostBinToolVariable("aconfig-to-metalava-flags", "aconfig-to-metalava-flags")
 }
 
 type javaBuilderFlags struct {
diff --git a/java/droidstubs.go b/java/droidstubs.go
index caad688..b3241cc 100644
--- a/java/droidstubs.go
+++ b/java/droidstubs.go
@@ -821,19 +821,17 @@
 		}
 	}
 
-	if len(aconfigFlagsPaths) == 0 {
-		// This argument should not be added for "everything" stubs
-		cmd.Flag("--revert-annotation android.annotation.FlaggedApi")
-		return
-	}
+	// If aconfigFlagsPaths is empty then it is still important to generate the
+	// Metalava flags config file, albeit with an empty set of flags, so that all
+	// flagged APIs will be reverted.
 
-	releasedFlaggedApisFile := android.PathForModuleOut(ctx, fmt.Sprintf("released-flagged-apis-%s.txt", stubsType.String()))
-	revertAnnotationsFile := android.PathForModuleOut(ctx, fmt.Sprintf("revert-annotations-%s.txt", stubsType.String()))
+	releasedFlagsFile := android.PathForModuleOut(ctx, fmt.Sprintf("released-flags-%s.pb", stubsType.String()))
+	metalavaFlagsConfigFile := android.PathForModuleOut(ctx, fmt.Sprintf("flags-config-%s.xml", stubsType.String()))
 
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        gatherReleasedFlaggedApisRule,
 		Inputs:      aconfigFlagsPaths,
-		Output:      releasedFlaggedApisFile,
+		Output:      releasedFlagsFile,
 		Description: fmt.Sprintf("%s gather aconfig flags", stubsType),
 		Args: map[string]string{
 			"flags_path":  android.JoinPathsWithPrefix(aconfigFlagsPaths, "--cache "),
@@ -843,12 +841,12 @@
 
 	ctx.Build(pctx, android.BuildParams{
 		Rule:        generateMetalavaRevertAnnotationsRule,
-		Input:       releasedFlaggedApisFile,
-		Output:      revertAnnotationsFile,
-		Description: fmt.Sprintf("%s revert annotations", stubsType),
+		Input:       releasedFlagsFile,
+		Output:      metalavaFlagsConfigFile,
+		Description: fmt.Sprintf("%s metalava flags config", stubsType),
 	})
 
-	cmd.FlagWithInput("@", revertAnnotationsFile)
+	cmd.FlagWithInput("--config-file ", metalavaFlagsConfigFile)
 }
 
 func (d *Droidstubs) commonMetalavaStubCmd(ctx android.ModuleContext, rule *android.RuleBuilder,
diff --git a/java/droidstubs_test.go b/java/droidstubs_test.go
index dfdf877..1f9d223 100644
--- a/java/droidstubs_test.go
+++ b/java/droidstubs_test.go
@@ -410,12 +410,12 @@
 
 	m := result.ModuleForTests(t, "foo", "android_common")
 	android.AssertStringDoesContain(t, "foo generates revert annotations file",
-		strings.Join(m.AllOutputs(), ""), "revert-annotations-exportable.txt")
+		strings.Join(m.AllOutputs(), ""), "flags-config-exportable.xml")
 
 	// revert-annotations.txt passed to exportable stubs generation metalava command
 	manifest := m.Output("metalava_exportable.sbox.textproto")
 	cmdline := String(android.RuleBuilderSboxProtoForTests(t, result.TestContext, manifest).Commands[0].Command)
-	android.AssertStringDoesContain(t, "flagged api hide command not included", cmdline, "revert-annotations-exportable.txt")
+	android.AssertStringDoesContain(t, "flagged api hide command not included", cmdline, "flags-config-exportable.xml")
 
 	android.AssertStringDoesContain(t, "foo generates exportable stubs jar",
 		strings.Join(m.AllOutputs(), ""), "exportable/foo-stubs.srcjar")
@@ -460,7 +460,7 @@
 
 	m := result.ModuleForTests(t, "foo", "android_common")
 
-	rule := m.Output("released-flagged-apis-exportable.txt")
+	rule := m.Output("released-flags-exportable.pb")
 	exposeWritableApisFilter := "--filter='state:ENABLED+permission:READ_ONLY' --filter='permission:READ_WRITE'"
 	android.AssertStringEquals(t, "Filter argument expected to contain READ_WRITE permissions", exposeWritableApisFilter, rule.Args["filter_args"])
 }
diff --git a/java/java_test.go b/java/java_test.go
index a6290a6..6df81e5 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -2912,12 +2912,12 @@
 
 	m := result.ModuleForTests(t, "foo", "android_common")
 	android.AssertStringDoesContain(t, "foo generates revert annotations file",
-		strings.Join(m.AllOutputs(), ""), "revert-annotations-exportable.txt")
+		strings.Join(m.AllOutputs(), ""), "flags-config-exportable.xml")
 
 	// revert-annotations.txt passed to exportable stubs generation metalava command
 	manifest := m.Output("metalava.sbox.textproto")
 	cmdline := String(android.RuleBuilderSboxProtoForTests(t, result.TestContext, manifest).Commands[0].Command)
-	android.AssertStringDoesContain(t, "flagged api hide command not included", cmdline, "revert-annotations-exportable.txt")
+	android.AssertStringDoesContain(t, "flagged api hide command not included", cmdline, "flags-config-exportable.xml")
 }
 
 func TestTestOnly(t *testing.T) {
diff --git a/scripts/Android.bp b/scripts/Android.bp
index 94163a5..c0e13d5 100644
--- a/scripts/Android.bp
+++ b/scripts/Android.bp
@@ -287,9 +287,13 @@
     ],
 }
 
-sh_binary_host {
-    name: "keep-flagged-apis",
-    src: "keep-flagged-apis.sh",
+python_binary_host {
+    name: "aconfig-to-metalava-flags",
+    main: "aconfig-to-metalava-flags.py",
+    srcs: ["aconfig-to-metalava-flags.py"],
+    libs: [
+        "libaconfig_python_proto",
+    ],
 }
 
 python_binary_host {
diff --git a/scripts/aconfig-to-metalava-flags.py b/scripts/aconfig-to-metalava-flags.py
new file mode 100644
index 0000000..efa85ec
--- /dev/null
+++ b/scripts/aconfig-to-metalava-flags.py
@@ -0,0 +1,103 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2025 The Android Open Source Project
+#
+# 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.
+
+"""Converts a set of aconfig protobuf flags to a Metalava config file."""
+
+# Formatted using `pyformat -i scripts/aconfig-to-metalava-flags.py`
+
+import argparse
+import sys
+import xml.etree.ElementTree as ET
+
+from protos import aconfig_pb2
+
+_READ_ONLY = aconfig_pb2.flag_permission.READ_ONLY
+_ENABLED = aconfig_pb2.flag_state.ENABLED
+_DISABLED = aconfig_pb2.flag_state.DISABLED
+
+# The namespace of the Metalava config file.
+CONFIG_NS = 'http://www.google.com/tools/metalava/config'
+
+
+def config_name(tag: str):
+  """Create a QName in the config namespace.
+
+  :param:tag the name of the entity in the config namespace.
+  """
+  return f'{{{CONFIG_NS}}}{tag}'
+
+
+def main():
+  """Program entry point."""
+  args_parser = argparse.ArgumentParser(
+      description='Generate Metalava flags config from aconfig protobuf',
+  )
+  args_parser.add_argument(
+      'input',
+      help='The path to the aconfig protobuf file',
+  )
+  args = args_parser.parse_args(sys.argv[1:])
+
+  # Read the parsed_flags from the protobuf file.
+  with open(args.input, 'rb') as f:
+    parsed_flags = aconfig_pb2.parsed_flags.FromString(f.read())
+
+  # Create the structure of the XML config file.
+  config = ET.Element(config_name('config'))
+  api_flags = ET.SubElement(config, config_name('api-flags'))
+  # Create an <api-flag> element for each parsed_flag.
+  for flag in parsed_flags.parsed_flag:
+    if flag.permission == _READ_ONLY:
+      # Ignore any read only disabled flags as Metalava assumes that as the
+      # default when an <api-flags/> element is provided so this reduces the
+      # size of the file.
+      if flag.state == _DISABLED:
+        continue
+      mutability = 'immutable'
+    else:
+      mutability = 'mutable'
+    if flag.state == _ENABLED:
+      status = 'enabled'
+    else:
+      status = 'disabled'
+    attributes = {
+        'package': flag.package,
+        'name': flag.name,
+        'mutability': mutability,
+        'status': status,
+    }
+    # Convert the attribute names into qualified names in, what will become, the
+    # default namespace for the XML file. This is needed to ensure that the
+    # attribute will be written in the XML file without a prefix, e.g.
+    # `name="flag_name"`. Without it, a namespace prefix, e.g. `ns1`, will be
+    # synthesized for the attribute when writing the XML file, i.e. it
+    # will be written as `ns1:name="flag_name"`. Strictly speaking, that is
+    # unnecessary as the "Namespaces in XML 1.0 (Third Edition)" specification
+    # says that unprefixed attribute names have no namespace.
+    qualified_attributes = {config_name(k): v for (k, v) in attributes.items()}
+    ET.SubElement(api_flags, config_name('api-flag'), qualified_attributes)
+
+  # Create a tree and add white space so it will pretty print when written out.
+  tree = ET.ElementTree(config)
+  ET.indent(tree)
+
+  # Write the tree using the config namespace as the default.
+  tree.write(sys.stdout, encoding='unicode', default_namespace=CONFIG_NS)
+  sys.stdout.close()
+
+
+if __name__ == '__main__':
+  main()
diff --git a/scripts/keep-flagged-apis.sh b/scripts/keep-flagged-apis.sh
deleted file mode 100755
index 48efb7a..0000000
--- a/scripts/keep-flagged-apis.sh
+++ /dev/null
@@ -1,37 +0,0 @@
-#!/bin/bash -e
-#
-# Copyright 2023 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.
-
-# Convert a list of flags in the input file to a list of metalava options
-# that will keep the APIs for those flags will hiding all other flagged
-# APIs.
-
-FLAGS="$1"
-
-FLAGGED="android.annotation.FlaggedApi"
-
-# Convert the list of feature flags in the input file to Metalava options
-# of the form `--revert-annotation !android.annotation.FlaggedApi("<flag>")`
-# to prevent the annotated APIs from being hidden, i.e. include the annotated
-# APIs in the SDK snapshots.
-while read -r line; do
-  # Escape and quote the key for sed
-  escaped_line=$(echo "$line" | sed "s/'/\\\'/g; s/ /\\ /g")
-
-  echo "--revert-annotation '!$FLAGGED(\"$escaped_line\")'"
-done < "$FLAGS"
-
-# Revert all flagged APIs, unless listed above.
-echo "--revert-annotation $FLAGGED"