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Commit 1922f4ed authored by Jared Duke's avatar Jared Duke
Browse files

Add feature XML file parsing support 

Add the ability to provide XML feature definition files (those used by
SystemConfig/PackageManager and distributed on devices) as inputs to
SystemFeaturesGenerator via the `--feature-xml-files` arg.

Note: This arg is not yet integrated into production codegen, but will
be used in future changes to scrape `<unavailable-feature />` defs in
product as inputs to codegen, behind a trunk stable build flag.

Bug: 203143243
Test: atest systemfeatures-gen-tests systemfeatures-gen-golden-tests
Flag: EXEMPT tool only change
Change-Id: I7d89106af2fe447e79ef8149b83741fcb371f7d3
parent 7f8e7295

tools/systemfeatures/Android.bp

+15 −1
Original line number Diff line number Diff line
@@ -82,15 +82,23 @@ java_plugin { 


genrule {

    name: "systemfeatures-gen-tests-srcs",

    srcs: [

        "tests/data/features-1.xml",

        "tests/data/features-2.xml",

    ],

    cmd: "$(location systemfeatures-gen-tool) com.android.systemfeatures.RwNoFeatures --readonly=false > $(location RwNoFeatures.java) && " +

        "$(location systemfeatures-gen-tool) com.android.systemfeatures.RoNoFeatures --readonly=true --feature-apis=WATCH > $(location RoNoFeatures.java) && " +

        "$(location systemfeatures-gen-tool) com.android.systemfeatures.RwFeatures --readonly=false --feature=WATCH:1 --feature=WIFI:0 --feature=VULKAN:UNAVAILABLE --feature=AUTO: > $(location RwFeatures.java) && " +

        "$(location systemfeatures-gen-tool) com.android.systemfeatures.RoFeatures --readonly=true --feature=WATCH:1 --feature=WIFI:0 --feature=VULKAN:UNAVAILABLE --feature=AUTO: --feature-apis=WATCH,PC > $(location RoFeatures.java)",

        "$(location systemfeatures-gen-tool) com.android.systemfeatures.RoFeatures --readonly=true --feature=WATCH:1 --feature=WIFI:0 --feature=VULKAN:UNAVAILABLE --feature=AUTO: --feature-apis=WATCH,PC > $(location RoFeatures.java) && " +

        "$(location systemfeatures-gen-tool) com.android.systemfeatures.RwFeaturesFromXml --readonly=false --feature-xml-files=$(location tests/data/features-1.xml),$(location tests/data/features-2.xml) > $(location RwFeaturesFromXml.java) && " +

        "$(location systemfeatures-gen-tool) com.android.systemfeatures.RoFeaturesFromXml --readonly=true --feature-xml-files=$(location tests/data/features-1.xml),$(location tests/data/features-2.xml) > $(location RoFeaturesFromXml.java)",

    out: [

        "RwNoFeatures.java",

        "RoNoFeatures.java",

        "RwFeatures.java",

        "RoFeatures.java",

        "RwFeaturesFromXml.java",

        "RoFeaturesFromXml.java",

    ],

    tools: ["systemfeatures-gen-tool"],

}
@@ -103,6 +111,10 @@ java_test_host { 
        "tests/src/**/*.java",

        ":systemfeatures-gen-tests-srcs",

    ],

    data: [

        "tests/data/features-1.xml",

        "tests/data/features-2.xml",

    ],

    test_options: {

        unit_test: true,

    },
@@ -130,6 +142,8 @@ genrule { 
        "tests/gen/RoNoFeatures.java.gen",

        "tests/gen/RwFeatures.java.gen",

        "tests/gen/RoFeatures.java.gen",

        "tests/gen/RwFeaturesFromXml.java.gen",

        "tests/gen/RoFeaturesFromXml.java.gen",

    ],

}

tools/systemfeatures/src/com/android/systemfeatures/SystemFeaturesGenerator.kt

+105 −9
Original line number Diff line number Diff line
@@ -22,7 +22,13 @@ import com.squareup.javapoet.JavaFile 
import com.squareup.javapoet.MethodSpec

import com.squareup.javapoet.ParameterizedTypeName

import com.squareup.javapoet.TypeSpec

import java.io.File

import javax.lang.model.element.Modifier

import javax.xml.parsers.DocumentBuilderFactory

import javax.xml.xpath.XPathConstants

import javax.xml.xpath.XPathFactory

import org.w3c.dom.Element

import org.w3c.dom.Node



/*

 * Simple Java code generator that takes as input a list of defined features and generates an
@@ -64,6 +70,7 @@ import javax.lang.model.element.Modifier 
 */

object SystemFeaturesGenerator {

    private const val FEATURE_ARG = "--feature="

    private const val FEATURE_XML_FILES_ARG = "--feature-xml-files="

    private const val FEATURE_APIS_ARG = "--feature-apis="

    private const val READONLY_ARG = "--readonly="

    private const val METADATA_ONLY_ARG = "--metadata-only="
@@ -93,6 +100,10 @@ object SystemFeaturesGenerator { 
        println("                           runtime passthrough API will be generated, regardless")

        println("                           of the `--readonly` flag. This allows decoupling the")

        println("                           API surface from variations in device feature sets.")

        println("  --feature-xml-files=\$XML_FILE_1,\$XML_FILE_2")

        println("                           A comma-separated list of XML permission feature files")

        println("                           to parse and add to the generated query APIs. The file")

        println("                           format matches that used by SystemConfig parsing.")

        println("  --metadata-only=true|false Whether to simply output metadata about the")

        println("                             generated API surface.")

    }
@@ -139,19 +150,37 @@ object SystemFeaturesGenerator { 
                        }

                    )

                }

                arg.startsWith(FEATURE_XML_FILES_ARG) -> {

                    featureArgs.addAll(

                        parseFeatureXmlFiles(arg.substring(FEATURE_XML_FILES_ARG.length).split(","))

                    )

                }

                else -> outputClassName = ClassName.bestGuess(arg)

            }

        }



        // First load in all of the feature APIs we want to generate. Explicit feature definitions

        // will then override this set with the appropriate readonly and version value.

        val features = mutableMapOf<String, FeatureInfo>()

        // will then override this set with the appropriate readonly and version value. Note that we

        // use a sorted map to ensure stable codegen outputs given identical inputs.

        val features = sortedMapOf<String, FeatureInfo>()

        featureApiArgs.associateByTo(

            features,

            { it },

            { FeatureInfo(it, version = null, readonly = false) },

        )

        featureArgs.associateByTo(



        // Multiple defs for the same feature may be present when aggregating permission files.

        // To preserve SystemConfig semantics, use the following ordering for insertion priority:

        //     * readonly (build-time overrides runtime)

        //     * unavailable (version == null, overrides available)

        //     * version (higher overrides lower)

        featureArgs

            .sortedWith(

                compareBy<FeatureInfo> { it.readonly }

                    .thenBy { it.version == null }

                    .thenBy { it.version }

            )

            .associateByTo(

                features,

                { it.name },

                { FeatureInfo(it.name, it.version, it.readonly && readonly) },
@@ -159,7 +188,7 @@ object SystemFeaturesGenerator { 


        outputClassName

            ?: run {

                println("Output class name must be provided.")

                System.err.println("Output class name must be provided.")

                usage()

                return

            }
@@ -214,7 +243,7 @@ object SystemFeaturesGenerator { 
    private fun parseFeatureName(name: String): String =

        when {

            name.startsWith("android") -> {

                SystemFeaturesLookup.getDeclaredFeatureVarNameFromValue(name)

                parseFeatureNameFromValue(name)

                    ?: throw IllegalArgumentException(

                        "Unrecognized Android system feature name: $name"

                    )
@@ -223,6 +252,73 @@ object SystemFeaturesGenerator { 
            else -> "FEATURE_$name"

        }



    private fun parseFeatureNameFromValue(name: String): String? =

        SystemFeaturesLookup.getDeclaredFeatureVarNameFromValue(name)





    /**

     * Parses a list of feature permission XML file paths into a list of FeatureInfo definitions.

     */

    private fun parseFeatureXmlFiles(filePaths: Collection<String>): Collection<FeatureInfo> =

        filePaths.flatMap {

            try {

                parseFeatureXmlFile(File(it))

            } catch (e: Exception) {

                throw IllegalArgumentException("Error parsing feature XML file: $it", e)

            }

        }



    /**

     * Parses a feature permission XML file into a (possibly empty) list of FeatureInfo definitions.

     */

    private fun parseFeatureXmlFile(file: File): Collection<FeatureInfo> {

        val doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(file)

        doc.documentElement.normalize()



        val xPath = XPathFactory.newInstance().newXPath()

        val rootElement =

            xPath.evaluate("/permissions", doc, XPathConstants.NODE) as? Element

                ?: xPath.evaluate("/config", doc, XPathConstants.NODE) as? Element

        if (rootElement == null) {

            System.err.println("Warning: No <permissions>/<config> elements found in ${file.path}")

            return emptyList()

        }



        return rootElement.childNodes.let { nodeList ->

            (0 until nodeList.length)

                .asSequence()

                .map { nodeList.item(it) }

                .filter { it.nodeType == Node.ELEMENT_NODE }

                .map { it as Element }

                .mapNotNull { element ->

                    when (element.tagName) {

                        "feature" -> parseFeatureElement(element)

                        "unavailable-feature" -> parseUnavailableFeatureElement(element)

                        else -> null

                    }

                }

                .toList()

        }

    }



    private fun parseFeatureElement(element: Element): FeatureInfo? {

        val name = parseFeatureNameFromValue(element.getAttribute("name")) ?: return null

        return if (element.getAttribute("notLowRam") == "true") {

            // If a feature is marked as being disabled on low-ram devices (notLowRam==true), we

            // we cannot finalize the exported feature version or its availability, as we don't

            // (yet) know whether the target product is low-ram.

            FeatureInfo(name, version = null, readonly = false)

        } else {

            val version = element.getAttribute("version")

            FeatureInfo(name, version.toIntOrNull() ?: 0, readonly = true)

        }

    }



    private fun parseUnavailableFeatureElement(element: Element): FeatureInfo? {

        val name = parseFeatureNameFromValue(element.getAttribute("name")) ?: return null

        return FeatureInfo(name, version = null, readonly = true)

    }



    /*

     * Adds per-feature query methods to the class with the form:

     * {@code public static boolean hasFeatureX(Context context)},

tools/systemfeatures/tests/data/features-1.xml

0 → 100644
+29 −0
Original line number Diff line number Diff line 
<?xml version="1.0" encoding="utf-8"?>

<!-- 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.

-->



<permissions>

     <!-- Implicit version=0 will be overridden in features-2.xml. -->

    <feature name="android.hardware.type.embedded" />

    <!--- Overridden by the pc <unavailable-feature /> def in features-2.xml. -->

    <feature name="android.hardware.type.pc" />

    <!-- Ignored as it's not a platform-defined feature. -->

    <feature name="com.arbitrary.feature" />

    <!-- Overrides the watch <feature /> def in features-2.xml. -->

    <unavailable-feature name="android.hardware.type.watch" />

    <!-- Exposed in the API but not as a build-time constant (readonly) feature,

         as we don't know if the device is low-ram. -->

    <feature name="android.hardware.bluetooth" notLowRam="true" />

</permissions>
 
 No newline at end of file

tools/systemfeatures/tests/data/features-2.xml

0 → 100644
+28 −0
Original line number Diff line number Diff line 
<?xml version="1.0" encoding="utf-8"?>

<!-- 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.

-->



<permissions>

    <!-- Overrides the embedded <feature /> version from features-1.xml. -->

    <feature name="android.hardware.type.embedded" version="1"/>

    <!-- Overridden by the <unavailable-feature /> def in features-1.xml. -->

    <feature name="android.hardware.type.watch" version="1" />

    <!-- Redundant with the wifi <feature /> def in features-1.xml. -->

    <feature name="android.hardware.wifi" />

    <!-- Ignored as it's not a platform-defined feature. -->

    <feature name="com.arbitrary.feature.2" />

    <!-- Overrides the pc <feature /> def from features-1.xml. -->

    <unavailable-feature name="android.hardware.type.pc" />

</permissions>
 
 No newline at end of file

tools/systemfeatures/tests/golden/RoFeatures.java.gen

+16 −16
Original line number Diff line number Diff line
@@ -22,13 +22,12 @@ import com.android.aconfig.annotations.AssumeTrueForR8; 
 */

public final class RoFeatures {

    /**

     * Check for FEATURE_WATCH.

     * Check for FEATURE_AUTO.

     *

     * @hide

     */

    @AssumeTrueForR8

    public static boolean hasFeatureWatch(Context context) {

        return true;

    public static boolean hasFeatureAuto(Context context) {

        return hasFeatureFallback(context, PackageManager.FEATURE_AUTO);

    }



    /**
@@ -41,32 +40,33 @@ public final class RoFeatures { 
    }



    /**

     * Check for FEATURE_WIFI.

     * Check for FEATURE_VULKAN.

     *

     * @hide

     */

    @AssumeTrueForR8

    public static boolean hasFeatureWifi(Context context) {

        return true;

    @AssumeFalseForR8

    public static boolean hasFeatureVulkan(Context context) {

        return false;

    }



    /**

     * Check for FEATURE_VULKAN.

     * Check for FEATURE_WATCH.

     *

     * @hide

     */

    @AssumeFalseForR8

    public static boolean hasFeatureVulkan(Context context) {

        return false;

    @AssumeTrueForR8

    public static boolean hasFeatureWatch(Context context) {

        return true;

    }



    /**

     * Check for FEATURE_AUTO.

     * Check for FEATURE_WIFI.

     *

     * @hide

     */

    public static boolean hasFeatureAuto(Context context) {

        return hasFeatureFallback(context, PackageManager.FEATURE_AUTO);

    @AssumeTrueForR8

    public static boolean hasFeatureWifi(Context context) {

        return true;

    }



    private static boolean hasFeatureFallback(Context context, String featureName) {
@@ -79,9 +79,9 @@ public final class RoFeatures { 
    @Nullable

    public static Boolean maybeHasFeature(String featureName, int version) {

        switch (featureName) {

            case PackageManager.FEATURE_VULKAN: return false;

            case PackageManager.FEATURE_WATCH: return 1 >= version;

            case PackageManager.FEATURE_WIFI: return 0 >= version;

            case PackageManager.FEATURE_VULKAN: return false;

            default: break;

        }

        return null;