Click any function or variable to jump to its definition.
If an API you rely on has changed, you can use Xref to find all instances of that function across the entire codebase to understand how to migrate your code. How to Use xref.aosp.org Effectively 1. Searching for Definitions and Usages
When viewing a source file (such as a .cpp , .java , or .hal file), almost every identifier is a clickable link. If you click on WindowManagerService , XREF immediately shows you where that class is defined and every place it is instantiated. 2. Advanced Search Operators xref aosp
Xref AOSP refers to instances of source code cross-referencers—most notably Google's official and the open-source OpenGrok engine—configured specifically for Android. Core Functions
Are you trying to understand the of a specific AOSP sub-project? Share public link Click any function or variable to jump to its definition
Select your desired Android version branch (e.g., android-14.0.0_r1 ). In the field, type ZygoteInit .
| Platform | Supported Versions / Branches | Key Features | Performance | Access | | :--- | :--- | :--- | :--- | :--- | | | Latest master branch, AndroidX libraries | Semantic analysis (Kythe), official Google tool | Instant, reliable | May require VPN from some regions | | aospxref.com | Android 10 to current (fast updates) | OpenGrok 2.0+, very fast updates, supports many search types | Excellent (200-300ms) | Unrestricted | | xrefandroid.com | Android 1.6 to 16.0, OpenHarmony 5.0+ | Supports Android, Android Kernel, and HarmonyOS code | Very good (800-900ms) | No VPN needed, fast from many regions | | androidxref.com | Android 4.4 to 9.0 (older branches) | OpenGrok 1.0, stable for older code | Slower (500-1000ms) | Unrestricted | Searching for Definitions and Usages When viewing a
This period saw the emergence of faster, more feature-rich platforms:
Point OpenGrok to your local AOSP root directory to generate the cross-reference data.
For developers, finding the definition of a specific function—say, AudioFlinger::openOutput() —by manually grepping through a local repo can take minutes. For reviewers trying to understand a patch's impact across subsystems, it’s a nightmare.