From a23bf1786be7c0738a4cf999c2957155bb32d5af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Wed, 19 Jul 2023 14:48:50 +0300
Subject: [PATCH] [clang] [MinGW] Pass LTO options to the linker

This matches what is done on other platforms too.

This fixes one part of
https://github.com/mstorsjo/llvm-mingw/issues/349.

Differential Revision: https://reviews.llvm.org/D158411
---
 clang/lib/Driver/ToolChains/MinGW.cpp | 6 ++++++
 clang/test/Driver/mingw-lto.c         | 4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Driver/ToolChains/MinGW.cpp b/clang/lib/Driver/ToolChains/MinGW.cpp
index b47041dcca70..4674e7fa268f 100644
--- a/clang/lib/Driver/ToolChains/MinGW.cpp
+++ b/clang/lib/Driver/ToolChains/MinGW.cpp
@@ -238,6 +238,12 @@ void tools::MinGW::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);
 
+  if (D.isUsingLTO()) {
+    assert(!Inputs.empty() && "Must have at least one input.");
+    addLTOOptions(TC, Args, CmdArgs, Output, Inputs[0],
+                  D.getLTOMode() == LTOK_Thin);
+  }
+
   if (C.getDriver().IsFlangMode()) {
     addFortranRuntimeLibraryPath(TC, Args, CmdArgs);
     addFortranRuntimeLibs(TC, CmdArgs);
diff --git a/clang/test/Driver/mingw-lto.c b/clang/test/Driver/mingw-lto.c
index 6f5652ddfb86..c10ad6b821bd 100644
--- a/clang/test/Driver/mingw-lto.c
+++ b/clang/test/Driver/mingw-lto.c
@@ -1,4 +1,6 @@
 // The default linker doesn't support LLVM bitcode
 // RUN: not %clang --target=i686-pc-windows-gnu %s -flto -fuse-ld=bfd
 // When using lld, this is allowed though.
-// RUN: %clang --target=i686-pc-windows-gnu -### %s -flto -fuse-ld=lld -B%S/Inputs/lld
+// RUN: %clang --target=i686-pc-windows-gnu -### %s -flto -fuse-ld=lld -B%S/Inputs/lld -femulated-tls 2>&1 | FileCheck %s
+
+// CHECK: "-plugin-opt=-emulated-tls"