From 95e9609b9dade04590b7f3b9f6c3f7b02d116b3f Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Fri, 24 Nov 2017 09:18:22 -0800 Subject: std: Flag Windows TLS dtor symbol as #[used] Turns out ThinLTO was internalizing this symbol and eliminating it. Worse yet if you compiled with LTO turns out no TLS destructors would run on Windows! The `#[used]` annotation should be a more bulletproof implementation (in the face of LTO) of preserving this symbol all the way through in LLVM and ensuring it makes it all the way to the linker which will take care of it. --- src/libstd/sys/windows/thread_local.rs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/libstd/sys') diff --git a/src/libstd/sys/windows/thread_local.rs b/src/libstd/sys/windows/thread_local.rs index 7ae9ed917bd..cdad320e122 100644 --- a/src/libstd/sys/windows/thread_local.rs +++ b/src/libstd/sys/windows/thread_local.rs @@ -200,8 +200,9 @@ unsafe fn register_dtor(key: Key, dtor: Dtor) { // the address of the symbol to ensure it sticks around. #[link_section = ".CRT$XLB"] -#[linkage = "external"] #[allow(dead_code, unused_variables)] +#[used] // we don't want LLVM eliminating this symbol for any reason, and + // when the symbol makes it to the linker the linker will take over pub static p_thread_callback: unsafe extern "system" fn(c::LPVOID, c::DWORD, c::LPVOID) = on_tls_callback; -- cgit 1.4.1-3-g733a5