Add golden tests for systemfeatures codegen

Add a simple golden test suite for systemfeature codegen. This can be
run via atest, or as a standalone script. The golden sources can be
updated via:

  ./frameworks/base/tools/systemfeatures/tests/golden_test.sh --update

Test: atest systemfeatures-gen-golden-tests
Bug: 203143243
Flag: NA

Change-Id: Iacb9558617845132ccfffbae34c333d39c84c065
diff --git a/tools/systemfeatures/tests/golden/RoFeatures.java.gen b/tools/systemfeatures/tests/golden/RoFeatures.java.gen
new file mode 100644
index 0000000..724639b
--- /dev/null
+++ b/tools/systemfeatures/tests/golden/RoFeatures.java.gen
@@ -0,0 +1,88 @@
+// This file is auto-generated. DO NOT MODIFY.
+// Args: com.android.systemfeatures.RoFeatures \
+//            --readonly=true \
+//            --feature=WATCH:1 \
+//            --feature=WIFI:0 \
+//            --feature=VULKAN:-1 \
+//            --feature=AUTO: \
+//            --feature-apis=WATCH,PC
+package com.android.systemfeatures;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import com.android.aconfig.annotations.AssumeFalseForR8;
+import com.android.aconfig.annotations.AssumeTrueForR8;
+
+/**
+ * @hide
+ */
+public final class RoFeatures {
+    /**
+     * Check for FEATURE_WATCH.
+     *
+     * @hide
+     */
+    @AssumeTrueForR8
+    public static boolean hasFeatureWatch(Context context) {
+        return true;
+    }
+
+    /**
+     * Check for FEATURE_PC.
+     *
+     * @hide
+     */
+    public static boolean hasFeaturePc(Context context) {
+        return hasFeatureFallback(context, PackageManager.FEATURE_PC);
+    }
+
+    /**
+     * Check for FEATURE_WIFI.
+     *
+     * @hide
+     */
+    @AssumeTrueForR8
+    public static boolean hasFeatureWifi(Context context) {
+        return true;
+    }
+
+    /**
+     * Check for FEATURE_VULKAN.
+     *
+     * @hide
+     */
+    @AssumeFalseForR8
+    public static boolean hasFeatureVulkan(Context context) {
+        return false;
+    }
+
+    /**
+     * Check for FEATURE_AUTO.
+     *
+     * @hide
+     */
+    @AssumeFalseForR8
+    public static boolean hasFeatureAuto(Context context) {
+        return false;
+    }
+
+    private static boolean hasFeatureFallback(Context context, String featureName) {
+        return context.getPackageManager().hasSystemFeature(featureName, 0);
+    }
+
+    /**
+     * @hide
+     */
+    @Nullable
+    public static Boolean maybeHasFeature(String featureName, int version) {
+        switch (featureName) {
+            case PackageManager.FEATURE_WATCH: return 1 >= version;
+            case PackageManager.FEATURE_WIFI: return 0 >= version;
+            case PackageManager.FEATURE_VULKAN: return -1 >= version;
+            case PackageManager.FEATURE_AUTO: return false;
+            default: break;
+        }
+        return null;
+    }
+}
diff --git a/tools/systemfeatures/tests/golden/RoNoFeatures.java.gen b/tools/systemfeatures/tests/golden/RoNoFeatures.java.gen
new file mode 100644
index 0000000..59c5b4e
--- /dev/null
+++ b/tools/systemfeatures/tests/golden/RoNoFeatures.java.gen
@@ -0,0 +1,35 @@
+// This file is auto-generated. DO NOT MODIFY.
+// Args: com.android.systemfeatures.RoNoFeatures \
+//            --readonly=true \
+//            --feature-apis=WATCH
+package com.android.systemfeatures;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.content.pm.PackageManager;
+
+/**
+ * @hide
+ */
+public final class RoNoFeatures {
+    /**
+     * Check for FEATURE_WATCH.
+     *
+     * @hide
+     */
+    public static boolean hasFeatureWatch(Context context) {
+        return hasFeatureFallback(context, PackageManager.FEATURE_WATCH);
+    }
+
+    private static boolean hasFeatureFallback(Context context, String featureName) {
+        return context.getPackageManager().hasSystemFeature(featureName, 0);
+    }
+
+    /**
+     * @hide
+     */
+    @Nullable
+    public static Boolean maybeHasFeature(String featureName, int version) {
+        return null;
+    }
+}
diff --git a/tools/systemfeatures/tests/golden/RwFeatures.java.gen b/tools/systemfeatures/tests/golden/RwFeatures.java.gen
new file mode 100644
index 0000000..6f89759
--- /dev/null
+++ b/tools/systemfeatures/tests/golden/RwFeatures.java.gen
@@ -0,0 +1,65 @@
+// This file is auto-generated. DO NOT MODIFY.
+// Args: com.android.systemfeatures.RwFeatures \
+//            --readonly=false \
+//            --feature=WATCH:1 \
+//            --feature=WIFI:0 \
+//            --feature=VULKAN:-1 \
+//            --feature=AUTO:
+package com.android.systemfeatures;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.content.pm.PackageManager;
+
+/**
+ * @hide
+ */
+public final class RwFeatures {
+    /**
+     * Check for FEATURE_WATCH.
+     *
+     * @hide
+     */
+    public static boolean hasFeatureWatch(Context context) {
+        return hasFeatureFallback(context, PackageManager.FEATURE_WATCH);
+    }
+
+    /**
+     * Check for FEATURE_WIFI.
+     *
+     * @hide
+     */
+    public static boolean hasFeatureWifi(Context context) {
+        return hasFeatureFallback(context, PackageManager.FEATURE_WIFI);
+    }
+
+    /**
+     * Check for FEATURE_VULKAN.
+     *
+     * @hide
+     */
+    public static boolean hasFeatureVulkan(Context context) {
+        return hasFeatureFallback(context, PackageManager.FEATURE_VULKAN);
+    }
+
+    /**
+     * Check for FEATURE_AUTO.
+     *
+     * @hide
+     */
+    public static boolean hasFeatureAuto(Context context) {
+        return hasFeatureFallback(context, PackageManager.FEATURE_AUTO);
+    }
+
+    private static boolean hasFeatureFallback(Context context, String featureName) {
+        return context.getPackageManager().hasSystemFeature(featureName, 0);
+    }
+
+    /**
+     * @hide
+     */
+    @Nullable
+    public static Boolean maybeHasFeature(String featureName, int version) {
+        return null;
+    }
+}
diff --git a/tools/systemfeatures/tests/golden/RwNoFeatures.java.gen b/tools/systemfeatures/tests/golden/RwNoFeatures.java.gen
new file mode 100644
index 0000000..2111d56
--- /dev/null
+++ b/tools/systemfeatures/tests/golden/RwNoFeatures.java.gen
@@ -0,0 +1,24 @@
+// This file is auto-generated. DO NOT MODIFY.
+// Args: com.android.systemfeatures.RwNoFeatures \
+//            --readonly=false
+package com.android.systemfeatures;
+
+import android.annotation.Nullable;
+import android.content.Context;
+
+/**
+ * @hide
+ */
+public final class RwNoFeatures {
+    private static boolean hasFeatureFallback(Context context, String featureName) {
+        return context.getPackageManager().hasSystemFeature(featureName, 0);
+    }
+
+    /**
+     * @hide
+     */
+    @Nullable
+    public static Boolean maybeHasFeature(String featureName, int version) {
+        return null;
+    }
+}
diff --git a/tools/systemfeatures/tests/golden_test.sh b/tools/systemfeatures/tests/golden_test.sh
new file mode 100755
index 0000000..c249254
--- /dev/null
+++ b/tools/systemfeatures/tests/golden_test.sh
@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+# Copyright (C) 2024 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.
+
+set -e
+
+GEN_DIR="tests/gen"
+GOLDEN_DIR="tests/golden"
+
+if [[ $(basename $0) == "golden_test.sh" ]]; then
+  # We're running via command-line, so we need to:
+  #   1) manually update generated srcs
+  #   2) use absolute paths
+  if [ -z $ANDROID_BUILD_TOP ]; then
+    echo "You need to source and lunch before you can use this script directly."
+    exit 1
+  fi
+  GEN_DIR="$ANDROID_BUILD_TOP/out/soong/.intermediates/frameworks/base/tools/systemfeatures/systemfeatures-gen-tests-golden-srcs/gen/$GEN_DIR"
+  GOLDEN_DIR="$ANDROID_BUILD_TOP/frameworks/base/tools/systemfeatures/$GOLDEN_DIR"
+  rm -rf "$GEN_DIR"
+  "$ANDROID_BUILD_TOP"/build/soong/soong_ui.bash --make-mode systemfeatures-gen-tests-golden-srcs
+fi
+
+if [[ "$1" == "--update" ]]; then
+  rm -rf "$GOLDEN_DIR"
+  cp -R "$GEN_DIR" "$GOLDEN_DIR"
+  echo "Updated golden test files."
+else
+  echo "Running diff from test output against golden test files..."
+  if diff -ruN "$GOLDEN_DIR" "$GEN_DIR" ; then
+    echo "No changes."
+  else
+    echo
+    echo "----------------------------------------------------------------------------------------"
+    echo "If changes look OK, run:"
+    echo "  \$ANDROID_BUILD_TOP/frameworks/base/tools/systemfeatures/tests/golden_test.sh --update"
+    echo "----------------------------------------------------------------------------------------"
+    exit 1
+  fi
+fi
diff --git a/tools/systemfeatures/tests/Context.java b/tools/systemfeatures/tests/src/Context.java
similarity index 100%
rename from tools/systemfeatures/tests/Context.java
rename to tools/systemfeatures/tests/src/Context.java
diff --git a/tools/systemfeatures/tests/PackageManager.java b/tools/systemfeatures/tests/src/PackageManager.java
similarity index 100%
rename from tools/systemfeatures/tests/PackageManager.java
rename to tools/systemfeatures/tests/src/PackageManager.java
diff --git a/tools/systemfeatures/tests/SystemFeaturesGeneratorTest.java b/tools/systemfeatures/tests/src/SystemFeaturesGeneratorTest.java
similarity index 100%
rename from tools/systemfeatures/tests/SystemFeaturesGeneratorTest.java
rename to tools/systemfeatures/tests/src/SystemFeaturesGeneratorTest.java
diff --git a/tools/systemfeatures/tests/systemfeatures-gen-golden-tests.xml b/tools/systemfeatures/tests/systemfeatures-gen-golden-tests.xml
new file mode 100644
index 0000000..e3a5841
--- /dev/null
+++ b/tools/systemfeatures/tests/systemfeatures-gen-golden-tests.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2024 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.
+-->
+<configuration description="Runs systemfeatures-gen golden diff test">
+    <test class="com.android.tradefed.testtype.binary.ExecutableHostTest" >
+      <option name="binary" value="systemfeatures-gen-golden-tests.sh"/>
+    </test>
+</configuration>