Auto merge of rust-lang#85806 - ATiltedTree:android-ndk-beta, r=petro…

…chenkov

Support Android ndk versions `r23-beta3` and up

Since android ndk version `r23-beta3`, `libgcc` has been replaced with `libunwind`. This moves the linking of `libgcc`/`libunwind` into the `unwind` crate where we check if the system compiler can find `libunwind` and fall back to `libgcc` if needed.

Cargo.lock

@@ -652,9 +652,9 @@ dependencies = [
 
 [[package]]
 name = "compiler_builtins"
-version = "0.1.43"
+version = "0.1.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65af2dcae4779003dfa91aedc6ade7bdc7ba685944e50a8b4f9380df376a4466"
+checksum = "787187ae221adfcda34b03006f1617099e4ae26b50e5a4db282496014ab75837"
 dependencies = [
  "cc",
  "rustc-std-workspace-core",

library/std/Cargo.toml

@@ -17,7 +17,7 @@ panic_unwind = { path = "../panic_unwind", optional = true }
 panic_abort = { path = "../panic_abort" }
 core = { path = "../core" }
 libc = { version = "0.2.93", default-features = false, features = ['rustc-dep-of-std'] }
-compiler_builtins = { version = "0.1.43" }
+compiler_builtins = { version = "0.1.44" }
 profiler_builtins = { path = "../profiler_builtins", optional = true }
 unwind = { path = "../unwind" }
 hashbrown = { version = "0.11", default-features = false, features = ['rustc-dep-of-std'] }

library/std/src/sys/unix/mod.rs

@@ -210,7 +210,6 @@ cfg_if::cfg_if! {
     if #[cfg(target_os = "android")] {
         #[link(name = "dl")]
         #[link(name = "log")]
-        #[link(name = "gcc")]
         extern "C" {}
     } else if #[cfg(target_os = "freebsd")] {
         #[link(name = "execinfo")]

library/unwind/build.rs

@@ -20,6 +20,20 @@ fn main() {
         // linking for Linux is handled in lib.rs
         if target.contains("musl") {
             llvm_libunwind::compile();
+        } else if target.contains("android") {
+            let build = cc::Build::new();
+
+            // Since ndk r23 beta 3 `libgcc` was replaced with `libunwind` thus
+            // check if we have `libunwind` available and if so use it. Otherwise
+            // fall back to `libgcc` to support older ndk versions.
+            let has_unwind =
+                build.is_flag_supported("-lunwind").expect("Unable to invoke compiler");
+
+            if has_unwind {
+                println!("cargo:rustc-link-lib=unwind");
+            } else {
+                println!("cargo:rustc-link-lib=gcc");
+            }
         }
     } else if target.contains("freebsd") {
         println!("cargo:rustc-link-lib=gcc_s");