Use #[inline] on Windows for thread local access

Author: Zoxc

library/std/src/sys/common/thread_local/fast_local.rs

@@ -10,7 +10,7 @@
 macro_rules! __thread_local_inner {
  // used to generate the `LocalKey` value for const-initialized thread locals
  (@key $t:ty, const $init:expr) => {{
- #[cfg_attr(not(windows), inline)] // see comments below
+ #[cfg_attr(not(bootstrap), inline)]
  #[deny(unsafe_op_in_unsafe_fn)]
  unsafe fn __getit(
  _init: $crate::option::Option<&mut $crate::option::Option<$t>>,
@@ -77,29 +77,7 @@ macro_rules! __thread_local_inner {
  #[inline]
  fn __init() -> $t { $init }
 
- // When reading this function you might ask "why is this inlined
- // everywhere other than Windows?", and that's a very reasonable
- // question to ask. The short story is that it segfaults rustc if
- // this function is inlined. The longer story is that Windows looks
- // to not support `extern` references to thread locals across DLL
- // boundaries. This appears to at least not be supported in the ABI
- // that LLVM implements.
- //
- // Because of this we never inline on Windows, but we do inline on
- // other platforms (where external references to thread locals
- // across DLLs are supported). A better fix for this would be to
- // inline this function on Windows, but only for "statically linked"
- // components. For example if two separately compiled rlibs end up
- // getting linked into a DLL then it's fine to inline this function
- // across that boundary. It's only not fine to inline this function
- // across a DLL boundary. Unfortunately rustc doesn't currently
- // have this sort of logic available in an attribute, and it's not
- // clear that rustc is even equipped to answer this (it's more of a
- // Cargo question kinda). This means that, unfortunately, Windows
- // gets the pessimistic path for now where it's never inlined.
- //
- // The issue of "should enable on Windows sometimes" is #84933
- #[cfg_attr(not(windows), inline)]
+ #[cfg_attr(not(bootstrap), inline)]
  unsafe fn __getit(
  init: $crate::option::Option<&mut $crate::option::Option<$t>>,
  ) -> $crate::option::Option<&'static $t> {

library/std/src/sys/common/thread_local/os_local.rs

@@ -10,7 +10,7 @@
 macro_rules! __thread_local_inner {
  // used to generate the `LocalKey` value for const-initialized thread locals
  (@key $t:ty, const $init:expr) => {{
- #[cfg_attr(not(windows), inline)] // see comments below
+ #[cfg_attr(not(bootstrap), inline)]
  #[deny(unsafe_op_in_unsafe_fn)]
  unsafe fn __getit(
  _init: $crate::option::Option<&mut $crate::option::Option<$t>>,
@@ -49,29 +49,7 @@ macro_rules! __thread_local_inner {
  #[inline]
  fn __init() -> $t { $init }
 
- // When reading this function you might ask "why is this inlined
- // everywhere other than Windows?", and that's a very reasonable
- // question to ask. The short story is that it segfaults rustc if
- // this function is inlined. The longer story is that Windows looks
- // to not support `extern` references to thread locals across DLL
- // boundaries. This appears to at least not be supported in the ABI
- // that LLVM implements.
- //
- // Because of this we never inline on Windows, but we do inline on
- // other platforms (where external references to thread locals
- // across DLLs are supported). A better fix for this would be to
- // inline this function on Windows, but only for "statically linked"
- // components. For example if two separately compiled rlibs end up
- // getting linked into a DLL then it's fine to inline this function
- // across that boundary. It's only not fine to inline this function
- // across a DLL boundary. Unfortunately rustc doesn't currently
- // have this sort of logic available in an attribute, and it's not
- // clear that rustc is even equipped to answer this (it's more of a
- // Cargo question kinda). This means that, unfortunately, Windows
- // gets the pessimistic path for now where it's never inlined.
- //
- // The issue of "should enable on Windows sometimes" is #84933
- #[cfg_attr(not(windows), inline)]
+ #[cfg_attr(not(bootstrap), inline)]
  unsafe fn __getit(
  init: $crate::option::Option<&mut $crate::option::Option<$t>>,
  ) -> $crate::option::Option<&'static $t> {