diff --git a/core/java/com/android/internal/content/om/OverlayConfigParser.java b/core/java/com/android/internal/content/om/OverlayConfigParser.java
index faaf7d5cef18f158a8fcb7016a971e7b418d30b9..8132652ed6f4cf3bc3793419164a91e65330abe5 100644
--- a/core/java/com/android/internal/content/om/OverlayConfigParser.java
+++ b/core/java/com/android/internal/content/om/OverlayConfigParser.java
@@ -24,6 +24,8 @@ import android.content.pm.PackagePartitions;
import android.content.pm.PackagePartitions.SystemPartition;
import android.os.Build;
import android.os.FileUtils;
+import android.os.SystemProperties;
+import android.text.TextUtils;
import android.util.ArraySet;
import android.util.Log;
import android.util.Xml;
@@ -241,6 +243,18 @@ public final class OverlayConfigParser {
}
}
+ @FunctionalInterface
+ public interface SysPropWrapper{
+ /**
+ * Get system property
+ *
+ * @param property the key to look up.
+ *
+ * @return The property value if found, empty string otherwise.
+ */
+ String get(String property);
+ }
+
/**
* Retrieves overlays configured within the partition in increasing priority order.
*
@@ -319,6 +333,76 @@ public final class OverlayConfigParser {
}
}
+ /**
+ * Expand the property inside a rro configuration path.
+ *
+ * A RRO configuration can contain a property, this method expands
+ * the property to its value.
+ *
+ * Only read only properties allowed, prefixed with ro. Other
+ * properties will raise exception.
+ *
+ * Only a single property in the path is allowed.
+ *
+ * Example "${ro.boot.hardware.sku}/config.xml" would expand to
+ * "G020N/config.xml"
+ *
+ * @param configPath path to expand
+ * @param sysPropWrapper method used for reading properties
+ *
+ * @return The expanded path. Returns null if configPath is null.
+ */
+ @VisibleForTesting
+ public static String expandProperty(String configPath,
+ SysPropWrapper sysPropWrapper) {
+ if (configPath == null) {
+ return null;
+ }
+
+ int propStartPos = configPath.indexOf("${");
+ if (propStartPos == -1) {
+ // No properties inside the string, return as is
+ return configPath;
+ }
+
+ final StringBuilder sb = new StringBuilder();
+ sb.append(configPath.substring(0, propStartPos));
+
+ // Read out the end position
+ int propEndPos = configPath.indexOf("}", propStartPos);
+ if (propEndPos == -1) {
+ throw new IllegalStateException("Malformed property, unmatched braces, in: "
+ + configPath);
+ }
+
+ // Confirm that there is only one property inside the string
+ if (configPath.indexOf("${", propStartPos + 2) != -1) {
+ throw new IllegalStateException("Only a single property supported in path: "
+ + configPath);
+ }
+
+ final String propertyName = configPath.substring(propStartPos + 2, propEndPos);
+ if (!propertyName.startsWith("ro.")) {
+ throw new IllegalStateException("Only read only properties can be used when "
+ + "merging RRO config files: " + propertyName);
+ }
+ final String propertyValue = sysPropWrapper.get(propertyName);
+ if (TextUtils.isEmpty(propertyValue)) {
+ throw new IllegalStateException("Property is empty or doesn't exist: " + propertyName);
+ }
+ Log.d(TAG, String.format("Using property in overlay config path: \"%s\"", propertyName));
+ sb.append(propertyValue);
+
+ // propEndPos points to '}', need to step to next character, might be outside of string
+ propEndPos = propEndPos + 1;
+ // Append the remainder, if exists
+ if (propEndPos < configPath.length()) {
+ sb.append(configPath.substring(propEndPos));
+ }
+
+ return sb.toString();
+ }
+
/**
* Parses a <merge> tag within an overlay configuration file.
*
@@ -331,10 +415,21 @@ public final class OverlayConfigParser {
@Nullable OverlayScanner scanner,
@Nullable Map<String, ParsedOverlayInfo> packageManagerOverlayInfos,
@NonNull ParsingContext parsingContext) {
- final String path = parser.getAttributeValue(null, "path");
+ final String path;
+
+ try {
+ SysPropWrapper sysPropWrapper = p -> {
+ return SystemProperties.get(p, "");
+ };
+ path = expandProperty(parser.getAttributeValue(null, "path"), sysPropWrapper);
+ } catch (IllegalStateException e) {
+ throw new IllegalStateException(String.format("<merge> path expand error in %s at %s",
+ configFile, parser.getPositionDescription()), e);
+ }
+
if (path == null) {
- throw new IllegalStateException(String.format("<merge> without path in %s at %s"
- + configFile, parser.getPositionDescription()));
+ throw new IllegalStateException(String.format("<merge> without path in %s at %s",
+ configFile, parser.getPositionDescription()));
}
if (path.startsWith("/")) {
diff --git a/core/tests/coretests/src/com/android/internal/content/res/OverlayConfigParserTest.java b/core/tests/coretests/src/com/android/internal/content/res/OverlayConfigParserTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..4eccbe5f1dc473acadddf136e2045c346014c0fb
--- /dev/null
+++ b/core/tests/coretests/src/com/android/internal/content/res/OverlayConfigParserTest.java
@@ -0,0 +1,119 @@
+/*
+ * 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.
+ */
+
+package com.android.internal.content.res;
+
+import static com.android.internal.content.om.OverlayConfigParser.SysPropWrapper;
+
+import static org.junit.Assert.assertEquals;
+
+import android.platform.test.annotations.Presubmit;
+
+import androidx.test.runner.AndroidJUnit4;
+
+import com.android.internal.content.om.OverlayConfigParser;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@Presubmit
+@RunWith(AndroidJUnit4.class)
+public class OverlayConfigParserTest {
+ @Test(expected = IllegalStateException.class)
+ public void testMergePropNotRoProp() {
+ SysPropWrapper sysProp = p -> {
+ return "dummy_value";
+ };
+ OverlayConfigParser.expandProperty("${persist.value}/path", sysProp);
+ }
+
+ @Test(expected = IllegalStateException.class)
+ public void testMergePropMissingEndBracket() {
+ SysPropWrapper sysProp = p -> {
+ return "dummy_value";
+ };
+ OverlayConfigParser.expandProperty("${ro.value/path", sysProp);
+ }
+
+ @Test(expected = IllegalStateException.class)
+ public void testMergeOnlyPropStart() {
+ SysPropWrapper sysProp = p -> {
+ return "dummy_value";
+ };
+ OverlayConfigParser.expandProperty("path/${", sysProp);
+ }
+
+ @Test(expected = IllegalStateException.class)
+ public void testMergePropInProp() {
+ SysPropWrapper sysProp = p -> {
+ return "dummy_value";
+ };
+ OverlayConfigParser.expandProperty("path/${${ro.value}}", sysProp);
+ }
+
+ /**
+ * The path is only allowed to contain one property.
+ */
+ @Test(expected = IllegalStateException.class)
+ public void testMergePropMultipleProps() {
+ SysPropWrapper sysProp = p -> {
+ return "dummy_value";
+ };
+ OverlayConfigParser.expandProperty("${ro.value}/path${ro.value2}/path", sysProp);
+ }
+
+ @Test
+ public void testMergePropOneProp() {
+ final SysPropWrapper sysProp = p -> {
+ if ("ro.value".equals(p)) {
+ return "dummy_value";
+ } else {
+ return "invalid";
+ }
+ };
+
+ // Property in the beginnig of the string
+ String result = OverlayConfigParser.expandProperty("${ro.value}/path",
+ sysProp);
+ assertEquals("dummy_value/path", result);
+
+ // Property in the middle of the string
+ result = OverlayConfigParser.expandProperty("path/${ro.value}/file",
+ sysProp);
+ assertEquals("path/dummy_value/file", result);
+
+ // Property at the of the string
+ result = OverlayConfigParser.expandProperty("path/${ro.value}",
+ sysProp);
+ assertEquals("path/dummy_value", result);
+
+ // Property is the entire string
+ result = OverlayConfigParser.expandProperty("${ro.value}",
+ sysProp);
+ assertEquals("dummy_value", result);
+ }
+
+ @Test
+ public void testMergePropNoProp() {
+ final SysPropWrapper sysProp = p -> {
+ return "dummy_value";
+ };
+
+ final String path = "no_props/path";
+ String result = OverlayConfigParser.expandProperty(path, sysProp);
+ assertEquals(path, result);
+ }
+}