Auto merge of #51828 - kennytm:no-simd-swap-for-mac, r=alexcrichton

Do not allow LLVM to increase a TLS's alignment on macOS.

This addresses the various TLS segfault on macOS 10.10.

Fix #51794.
Fix #51758.
Fix #50867.
Fix #48866.
Fix #46355.
Fix #44056.

1 files changed, 40 insertions, 0 deletions

diff --git a/src/test/codegen/issue-44056-macos-tls-align.rs b/src/test/codegen/issue-44056-macos-tls-align.rs
new file mode 100644
index 00000000000..3235ef0bb33
--- /dev/null
+++ b/src/test/codegen/issue-44056-macos-tls-align.rs
@@ -0,0 +1,40 @@
+// Copyright 2018 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 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-tidy-linelength
+// only-macos
+// no-system-llvm
+// min-llvm-version 6.0
+// compile-flags: -O
+
+#![crate_type = "rlib"]
+#![feature(thread_local)]
+
+// CHECK: @STATIC_VAR_1 = internal thread_local unnamed_addr global <{ [32 x i8] }> zeroinitializer, section "__DATA,__thread_bss", align 4
+#[no_mangle]
+#[allow(private_no_mangle_statics)]
+#[thread_local]
+static mut STATIC_VAR_1: [u32; 8] = [0; 8];
+
+// CHECK: @STATIC_VAR_2 = internal thread_local unnamed_addr global <{ [32 x i8] }> <{{[^>]*}}>, section "__DATA,__thread_data", align 4
+#[no_mangle]
+#[allow(private_no_mangle_statics)]
+#[thread_local]
+static mut STATIC_VAR_2: [u32; 8] = [4; 8];
+
+#[no_mangle]
+pub unsafe fn f(x: &mut [u32; 8]) {
+    std::mem::swap(x, &mut STATIC_VAR_1)
+}
+
+#[no_mangle]
+pub unsafe fn g(x: &mut [u32; 8]) {
+    std::mem::swap(x, &mut STATIC_VAR_2)
+}