From 1af95898e523a92f962c100db82a55a1a80632e7 Mon Sep 17 00:00:00 2001
From: Shravan Narayan <shravanrn@gmail.com>
Date: Tue, 15 Oct 2024 00:29:43 -0500
Subject: [PATCH] wasm2c: Cleanup TLS: check for __thread and declare TLS vars
 only when needed

---
 wasm2c/wasm-rt-impl.c | 2 ++
 wasm2c/wasm-rt-impl.h | 2 ++
 wasm2c/wasm-rt.h      | 9 ++++++---
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/wasm2c/wasm-rt-impl.c b/wasm2c/wasm-rt-impl.c
index 456c30257b..92616351db 100644
--- a/wasm2c/wasm-rt-impl.c
+++ b/wasm2c/wasm-rt-impl.c
@@ -73,7 +73,9 @@ WASM_RT_THREAD_LOCAL uint32_t wasm_rt_saved_call_stack_depth;
 static WASM_RT_THREAD_LOCAL void* g_alt_stack = NULL;
 #endif
 
+#ifndef WASM_RT_TRAP_HANDLER
 WASM_RT_THREAD_LOCAL wasm_rt_jmp_buf g_wasm_rt_jmp_buf;
+#endif
 
 #ifdef WASM_RT_TRAP_HANDLER
 extern void WASM_RT_TRAP_HANDLER(wasm_rt_trap_t code);
diff --git a/wasm2c/wasm-rt-impl.h b/wasm2c/wasm-rt-impl.h
index aa6f46d98b..ed46b09721 100644
--- a/wasm2c/wasm-rt-impl.h
+++ b/wasm2c/wasm-rt-impl.h
@@ -27,8 +27,10 @@
 extern "C" {
 #endif
 
+#ifndef WASM_RT_TRAP_HANDLER
 /** A setjmp buffer used for handling traps. */
 extern WASM_RT_THREAD_LOCAL wasm_rt_jmp_buf g_wasm_rt_jmp_buf;
+#endif
 
 #if WASM_RT_STACK_DEPTH_COUNT
 /** Saved call stack depth that will be restored in case a trap occurs. */
diff --git a/wasm2c/wasm-rt.h b/wasm2c/wasm-rt.h
index 3274a15d2f..c5bad6142e 100644
--- a/wasm2c/wasm-rt.h
+++ b/wasm2c/wasm-rt.h
@@ -79,10 +79,13 @@ extern "C" {
 
 #endif
 
-#ifdef _MSC_VER
-#define WASM_RT_THREAD_LOCAL __declspec(thread)
-#elif defined(WASM_RT_C11_AVAILABLE)
+#ifdef WASM_RT_C11_AVAILABLE
 #define WASM_RT_THREAD_LOCAL _Thread_local
+#elif defined(_MSC_VER)
+#define WASM_RT_THREAD_LOCAL __declspec(thread)
+#elif (defined(__GNUC__) || defined(__clang__)) && !defined(__APPLE__)
+// Disabled on Apple systems due to sporadic test failures.
+#define WASM_RT_THREAD_LOCAL __thread
 #else
 #define WASM_RT_THREAD_LOCAL
 #endif