From 231922802741afaf17e053f6ca14279b87115e92 Mon Sep 17 00:00:00 2001
From: Jordan Rose <jrose@signal.org>
Date: Wed, 17 Jul 2024 17:40:19 -0700
Subject: [PATCH] android: Don't strip debug info out of the AAR

This *greatly* increases the size of the artifacts uploaded to Maven,
but it looks like the libraries do correctly get stripped when the
final APK is built. (This was not true in the past.)

Also, make sure the built library includes a "build ID", or else the
stripped version of the library will be treated as a different
library, and all the line tables will go to waste.
---
 java/android/build.gradle | 2 ++
 rust/bridge/jni/build.rs  | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/java/android/build.gradle b/java/android/build.gradle
index edba9df7..7405a6dc 100644
--- a/java/android/build.gradle
+++ b/java/android/build.gradle
@@ -54,6 +54,8 @@ android {
             pickFirst 'lib/*/libsignal_jni.so'
             pickFirst 'lib/*/libsignal_jni_testing.so'
         }
+        // Defer stripping to the Android app project.
+        doNotStrip '**/*.so'
     }
 
     publishing {
diff --git a/rust/bridge/jni/build.rs b/rust/bridge/jni/build.rs
index 9f7bcfc4..457a6979 100644
--- a/rust/bridge/jni/build.rs
+++ b/rust/bridge/jni/build.rs
@@ -9,6 +9,9 @@ fn main() {
     if env::var("CARGO_CFG_TARGET_ARCH").expect("set by Cargo") == "aarch64"
         && env::var("CARGO_CFG_TARGET_OS").expect("set by Cargo") == "android"
     {
+        // --build-id ensures that Android Studio's LLDB can map stripped binaries back to their debug info
+        println!("cargo:rustc-cdylib-link-arg=-Wl,--build-id");
+
         // HACK: Force libdl to be linked.
         // Something about the Docker-based build results in it getting skipped;
         // if we figure out what, we can remove this.