From e39de2b8862ae43459324da84279366997265078 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Sun, 1 Oct 2023 23:42:16 +0300
Subject: [PATCH] [clang] [MinGW] Tolerate mingw specific linker options during
 compilation (#67891)

Prior to 591c4b64b3650884c2c68eb47d755ebb62981b99, the mingw specific
linker options -mthreads, -mconsole, -mwindows and -mdll would be
tolerated also at compile time, but generating a warning about being
unused.

After that commit, they were marked as target specific, which means that
it's an error if they're unused (which would consider them used for the
wrong target). These specific options are only relevant when linking,
but we want to tolerate them at compile time too, like before.

This was fixed for -mthreads in
a79995ca6004082774a87f7a58ab6be5343364b7, while the other options didn't
seem to be commonly used during compilation.

After the 17.x release, we've got more reports about this actually being
an issue, in #64464. Therefore, apply the same fix for them; marking
them as tolerated for mingw targets during compilation, even if they're
unused. Also add a testcase for -mthreads which was already handled.

Thus, this fixes #64464.
---
 clang/lib/Driver/ToolChains/MinGW.cpp    |  7 +++++--
 clang/test/Driver/mingw-linker-options.c | 10 ++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 clang/test/Driver/mingw-linker-options.c

diff --git a/clang/lib/Driver/ToolChains/MinGW.cpp b/clang/lib/Driver/ToolChains/MinGW.cpp
index 5af7ea985a28a1..5872e13bda358f 100644
--- a/clang/lib/Driver/ToolChains/MinGW.cpp
+++ b/clang/lib/Driver/ToolChains/MinGW.cpp
@@ -709,8 +709,11 @@ void toolchains::MinGW::addClangTargetOptions(
     }
   }
 
-  if (Arg *A = DriverArgs.getLastArgNoClaim(options::OPT_mthreads))
-    A->ignoreTargetSpecific();
+  for (auto Opt : {options::OPT_mthreads, options::OPT_mwindows,
+                   options::OPT_mconsole, options::OPT_mdll}) {
+    if (Arg *A = DriverArgs.getLastArgNoClaim(Opt))
+      A->ignoreTargetSpecific();
+  }
 }
 
 void toolchains::MinGW::AddClangCXXStdlibIncludeArgs(
diff --git a/clang/test/Driver/mingw-linker-options.c b/clang/test/Driver/mingw-linker-options.c
new file mode 100644
index 00000000000000..b4f1d05a719f3a
--- /dev/null
+++ b/clang/test/Driver/mingw-linker-options.c
@@ -0,0 +1,10 @@
+// RUN: %clang --target=x86_64-windows-gnu -c -mwindows %s -### 2>&1 | FileCheck %s --check-prefix=WARNING
+// RUN: %clang --target=x86_64-windows-gnu -c -mconsole %s -### 2>&1 | FileCheck %s --check-prefix=WARNING
+// RUN: %clang --target=x86_64-windows-gnu -c -mdll %s -### 2>&1 | FileCheck %s --check-prefix=WARNING
+// RUN: %clang --target=x86_64-windows-gnu -c -mthreads %s -### 2>&1 | FileCheck %s --check-prefix=WARNING
+// RUN: not %clang --target=x86_64-windows-msvc -c -mwindows %s -### 2>&1 | FileCheck %s --check-prefix=ERROR
+// RUN: not %clang --target=x86_64-windows-msvc -c -mconsole %s -### 2>&1 | FileCheck %s --check-prefix=ERROR
+// RUN: not %clang --target=x86_64-windows-msvc -c -mdll %s -### 2>&1 | FileCheck %s --check-prefix=ERROR
+// RUN: not %clang --target=x86_64-windows-msvc -c -mthreads %s -### 2>&1 | FileCheck %s --check-prefix=ERROR
+// WARNING: warning: argument unused during compilation: '{{.*}}' [-Wunused-command-line-argument]
+// ERROR: error: unsupported option '{{.*}}' for target '{{.*}}'