From 2baa073fb1dc1a3556d174b58e5bc94b28682119 Mon Sep 17 00:00:00 2001
From: quininer <quininer@live.com>
Date: Mon, 13 Nov 2023 20:48:23 +0800
Subject: [PATCH] Add emulated TLS support

Currently LLVM uses emutls by default
for some targets (such as android, openbsd),
but rust does not use it, because `has_thread_local` is false.

This commit has some changes to allow users to enable emutls:

1. add `-Zhas-thread-local` flag to specify
    that std uses `#[thread_local]` instead of pthread key.
2. when using emutls, decorate symbol names
    to find thread local symbol correctly.
3. change `-Zforce-emulated-tls` to `-Ztls-model=emulated`
    to explicitly specify whether to generate emutls.
---
 src/context.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/context.rs b/src/context.rs
index a043660ea632..893cad051618 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -569,5 +569,6 @@ fn to_gcc_tls_mode(tls_model: TlsModel) -> gccjit::TlsModel {
         TlsModel::LocalDynamic => gccjit::TlsModel::LocalDynamic,
         TlsModel::InitialExec => gccjit::TlsModel::InitialExec,
         TlsModel::LocalExec => gccjit::TlsModel::LocalExec,
+        TlsModel::Emulated => gccjit::TlsModel::GlobalDynamic,
     }
 }