Auto merge of #108089 - Zoxc:windows-tls, r=bjorn3

Support TLS access into dylibs on Windows

This allows access to `#[thread_local]`  in upstream dylibs on Windows by introducing a MIR shim to return the address of the thread local. Accesses that go into an upstream dylib will call the MIR shim to get the address of it.

`convert_tls_rvalues` is introduced in `rustc_codegen_ssa` which rewrites MIR TLS accesses to dummy calls which are replaced with calls to the MIR shims when the dummy calls are lowered to backend calls.

A new `dll_tls_export` target option enables this behavior with a `false` value which is set for Windows platforms.

This fixes https://github.com/rust-lang/rust/issues/84933.

1 files changed, 1 insertions, 0 deletions

diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index b69186c9451..5c7415192b9 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -271,6 +271,7 @@ impl<'tcx> Inliner<'tcx> {
             | InstanceDef::ClosureOnceShim { .. }
             | InstanceDef::DropGlue(..)
             | InstanceDef::CloneShim(..)
+            | InstanceDef::ThreadLocalShim(..)
             | InstanceDef::FnPtrAddrShim(..) => return Ok(()),
         }