[clang] [clang] [MinGW] Tolerate mingw specific linker options during compilation (PR #67891)

[Martin Storsjö via cfe-commits]

https://github.com/mstorsjo updated https://github.com/llvm/llvm-project/pull/67891

>From da64c467a35cf544df5346b512746715ffc3db32 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin at martin.st>
Date: Sun, 1 Oct 2023 00:29:21 +0300
Subject: [PATCH] [clang] [MinGW] Tolerate mingw specific linker options during
 compilation

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 5af7ea985a28a18..5872e13bda358f8 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 000000000000000..b4f1d05a719f3af
--- /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 '{{.*}}'