missing symbols on x86_64 android emulator

Cargo.lock

@@ -5290,6 +5290,7 @@ dependencies = [
  "flume",
  "futures-util",
  "getrandom",
+ "glob",
  "hex",
  "ifstructs",
  "jni",

veilid-core/Cargo.toml

@@ -279,6 +279,7 @@ wasm-logger = "0.2.0"
 
 [build-dependencies]
 capnpc = "0.18.0"
+glob = "0.3.1"
 
 [package.metadata.wasm-pack.profile.release]
 wasm-opt = ["-O", "--enable-mutable-globals"]

veilid-core/build.rs

@@ -1,4 +1,8 @@
-use std::process::{Command, Stdio};
+use glob::glob;
+use std::{
+    env,
+    process::{Command, Stdio},
+};
 
 const CAPNP_VERSION: &str = "1.0.1"; // Keep in sync with scripts/install_capnp.sh
 const PROTOC_VERSION: &str = "24.3"; // Keep in sync with scripts/install_protoc.sh
@@ -111,4 +115,25 @@ fn main() {
             .run()
             .expect("compiling schema");
     }
+
+    // Fix for missing __extenddftf2 on Android x86_64 Emulator
+    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
+    // if target_os == "android" || target_os == "linux" {
+    //     println!("cargo:rustc-link-lib=stdc++");
+    // } else {
+    //     println!("cargo:rustc-link-lib=c++");
+    // }
+    let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
+    if target_arch == "x86_64" && target_os == "android" {
+        let missing_library = "clang_rt.builtins-x86_64-android";
+        let android_ndk_home = env::var("ANDROID_NDK_HOME").expect("ANDROID_NDK_HOME not set");
+        let lib_path = glob(&format!("{android_ndk_home}/**/lib{missing_library}.a"))
+            .expect("failed to glob")
+            .next()
+            .expect("Need libclang_rt.builtins-x86_64-android.a")
+            .unwrap();
+        let lib_dir = lib_path.parent().unwrap();
+        println!("cargo:rustc-link-search={}", lib_dir.display());
+        println!("cargo:rustc-link-lib=static={missing_library}");
+    }
 }