fix: Android crash — thread-local arena freed after main() returned (v0.4.29)

- perry-native thread ran main() which initialized module-level arrays on
  the thread's arena. After main() returned, the thread exited, triggering
  arena Drop which freed all blocks. UI thread pump ticks then called
  getLevelInfo() on dangling pointers → SIGSEGV at getLevelInfo+44.
- Fix: park the perry-native thread after main() instead of letting it exit,
  keeping the arena and all module-level objects alive.
- Also: -Bsymbolic linker flag prevents ELF symbol interposition.

Author: proggeramlug

CLAUDE.md

@@ -8,7 +8,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Perry is a native TypeScript compiler written in Rust that compiles TypeScript source code directly to native executables. It uses SWC for TypeScript parsing and Cranelift for code generation.
 
-**Current Version:** 0.4.28
+**Current Version:** 0.4.29
 
 ## Workflow Requirements
 
@@ -140,6 +140,10 @@ Projects can list npm packages to compile natively instead of routing to V8. Con
 
 ## Recent Changes
 
+### v0.4.29
+- fix: Android crash in UI pump ticks — perry-native thread exited after `main()` returned, dropping the thread-local arena and freeing all module-level arrays/objects; UI thread's pump tick then called `getLevelInfo()` on dangling pointers → segfault. Fixed by parking the perry-native thread after init instead of letting it exit.
+- fix: Android `-Bsymbolic` linker flag prevents ELF symbol interposition (process's `main()` vs perry's `main()`)
+
 ### v0.4.28
 - fix: module-level arrays/objects with `Unknown`/`Any` HIR type loaded as F64 instead of I64 in functions — `analyze_module_var_types` set `is_union=true` for Unknown/Any, causing `is_pointer && !is_union` to select F64; init stored I64 but functions loaded F64, corrupting pointers on Android (FP flush-to-zero); now arrays/closures/maps/sets/buffers always use I64
 

Cargo.lock

@@ -85,7 +85,7 @@ opt-level = "s"       # Optimize for size in stdlib
 opt-level = 3
 
 [workspace.package]
-version = "0.4.28"
+version = "0.4.29"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/PerryTS/perry"

Cargo.toml

@@ -50,6 +50,8 @@ impl crate::codegen::Compiler {
             self.module.declare_function("_perry_user_main", Linkage::Export, &sig)?
         } else if self.is_entry_module {
             // Entry module: generate "main"
+            // On Android, -Bsymbolic-functions prevents the process's main() from
+            // being called instead of ours via ELF symbol interposition.
             match self.module.declare_function("main", Linkage::Export, &sig) {
                 Ok(id) => id,
                 Err(_) => {

crates/perry-codegen/src/module_init.rs

@@ -139,7 +139,7 @@ pub extern "C" fn Java_com_perry_app_PerryBridge_nativeShutdown(
 
 #[cfg(not(test))]
 extern "C" {
-    fn main();
+    fn main() -> i32;
 }
 
 // js_stdlib_init_dispatch and js_stdlib_process_pending — now provided by perry-runtime
@@ -191,9 +191,19 @@ pub extern "C" fn Java_com_perry_app_PerryBridge_nativeMain(
         main();
         __android_log_print(
             3, b"PerryJNI\0".as_ptr(),
-            b"nativeMain: main() returned\0".as_ptr(),
+            b"nativeMain: main() returned, parking thread\0".as_ptr(),
         );
     }
+
+    // Park this thread forever — do NOT let it exit.
+    // Module-level arrays/objects are allocated on this thread's arena.
+    // If the thread exits, the arena's Drop frees all blocks, turning
+    // every module-level pointer into a dangling reference. The UI thread's
+    // pump ticks call into compiled functions (getLevelInfo etc.) that read
+    // these pointers — segfault if the arena was freed.
+    loop {
+        std::thread::park();
+    }
 }
 
 // =============================================================================

crates/perry-ui-android/src/lib.rs

@@ -4352,6 +4352,11 @@ pub fn run(args: CompileArgs, format: OutputFormat, _use_color: bool, _verbose:
          .arg("-target").arg("aarch64-linux-android24")
          .arg("-Wl,-z,max-page-size=16384")
          .arg("-Wl,-z,separate-loadable-segments")
+         // Prevent ELF symbol interposition: bind all symbols within the .so
+         // to the .so's own definitions. Without this, PLT calls (e.g. to "main")
+         // can resolve to symbols from the host process (app_process/zygote),
+         // bypassing perry's module initialization chain.
+         .arg("-Wl,-Bsymbolic")
          // Allow unresolved symbols from namespace imports (import * as X).
          // The codegen emits short-name extern refs (__export_X) for namespace
          // imports that may not have a corresponding definition when the module