diff --git a/src/libstd/sys/windows/thread_local.rs b/src/libstd/sys/windows/thread_local.rs index 7550b7ce6c352..d9b7a59712b0c 100644 --- a/src/libstd/sys/windows/thread_local.rs +++ b/src/libstd/sys/windows/thread_local.rs @@ -221,8 +221,24 @@ unsafe fn unregister_dtor(key: Key) -> bool { // // # The article mentions crazy stuff about "/INCLUDE"? // -// It sure does! We include it below for MSVC targets, but it look like for GNU -// targets we don't require it. +// It sure does! Specifically we're talking about this quote: +// +// The Microsoft run-time library facilitates this process by defining a +// memory image of the TLS Directory and giving it the special name +// “__tls_used” (Intel x86 platforms) or “_tls_used” (other platforms). The +// linker looks for this memory image and uses the data there to create the +// TLS Directory. Other compilers that support TLS and work with the +// Microsoft linker must use this same technique. +// +// Basically what this means is that if we want support for our TLS +// destructors/our hook being called then we need to make sure the linker does +// not omit this symbol. Otherwise it will omit it and our callback won't be +// wired up. +// +// We don't actually use the `/INCLUDE` linker flag here like the article +// mentions because the Rust compiler doesn't propagate linker flags, but +// instead we use a shim function which performs a volatile 1-byte load from +// the address of the symbol to ensure it sticks around. #[link_section = ".CRT$XLB"] #[linkage = "external"] @@ -231,13 +247,6 @@ pub static p_thread_callback: unsafe extern "system" fn(LPVOID, DWORD, LPVOID) = on_tls_callback; -#[cfg(all(target_env = "msvc", target_pointer_width = "64"))] -#[link_args = "/INCLUDE:_tls_used"] -extern {} -#[cfg(all(target_env = "msvc", target_pointer_width = "32"))] -#[link_args = "/INCLUDE:__tls_used"] -extern {} - #[allow(warnings)] unsafe extern "system" fn on_tls_callback(h: LPVOID, dwReason: DWORD, @@ -247,6 +256,17 @@ unsafe extern "system" fn on_tls_callback(h: LPVOID, if dwReason == DLL_THREAD_DETACH || dwReason == DLL_PROCESS_DETACH { run_dtors(); } + + // See comments above for what this is doing. Note that we don't need this + // trickery on GNU windows, just on MSVC. + reference_tls_used(); + #[cfg(target_env = "msvc")] + unsafe fn reference_tls_used() { + extern { static _tls_used: u8; } + ::intrinsics::volatile_load(&_tls_used); + } + #[cfg(not(target_env = "msvc"))] + unsafe fn reference_tls_used() {} } #[allow(dead_code)] // actually called above diff --git a/src/test/run-pass/down-with-thread-dtors.rs b/src/test/run-pass/down-with-thread-dtors.rs index ee835785cbe5d..5c449d511d53b 100644 --- a/src/test/run-pass/down-with-thread-dtors.rs +++ b/src/test/run-pass/down-with-thread-dtors.rs @@ -12,6 +12,8 @@ thread_local!(static FOO: Foo = Foo); thread_local!(static BAR: Bar = Bar(1)); thread_local!(static BAZ: Baz = Baz); +static mut HIT: bool = false; + struct Foo; struct Bar(i32); struct Baz; @@ -31,8 +33,15 @@ impl Drop for Bar { } } +impl Drop for Baz { + fn drop(&mut self) { + unsafe { HIT = true; } + } +} + fn main() { std::thread::spawn(|| { FOO.with(|_| {}); }).join().unwrap(); + assert!(unsafe { HIT }); } diff --git a/src/test/run-pass/tls-dtors-are-run-in-a-static-binary.rs b/src/test/run-pass/tls-dtors-are-run-in-a-static-binary.rs new file mode 100644 index 0000000000000..da30100f67ff9 --- /dev/null +++ b/src/test/run-pass/tls-dtors-are-run-in-a-static-binary.rs @@ -0,0 +1,30 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// no-prefer-dynamic + +static mut HIT: bool = false; + +struct Foo; + +impl Drop for Foo { + fn drop(&mut self) { + unsafe { HIT = true; } + } +} + +thread_local!(static FOO: Foo = Foo); + +fn main() { + std::thread::spawn(|| { + FOO.with(|_| {}); + }).join().unwrap(); + assert!(unsafe { HIT }); +}