[Clang] Avoid using unwind library in the MSVC environment

We're seeing the following warnings with --rtlib=compiler-rt: lld-link: warning: ignoring unknown argument '--as-needed' lld-link: warning: ignoring unknown argument '-lunwind' lld-link: warning: ignoring unknown argument '--no-as-needed' MSVC doesn't use the unwind library, so just omit it. Differential Revision: https://reviews.llvm.org/D132440
llvm · Aug 24, 2022 · eca29d4 · eca29d4
1 parent df4e637
commit eca29d4
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diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -1529,7 +1529,7 @@ static void AddUnwindLibrary(const ToolChain &TC, const Driver &D,
   // Targets that don't use unwind libraries.
   if ((TC.getTriple().isAndroid() && UNW == ToolChain::UNW_Libgcc) ||
       TC.getTriple().isOSIAMCU() || TC.getTriple().isOSBinFormatWasm() ||
-      UNW == ToolChain::UNW_None)
+      TC.getTriple().isWindowsMSVCEnvironment() || UNW == ToolChain::UNW_None)
     return;
 
   LibGccType LGT = getLibGccType(TC, D, Args);

diff --git a/clang/test/Driver/compiler-rt-unwind.c b/clang/test/Driver/compiler-rt-unwind.c
@@ -88,6 +88,12 @@
 // RTLIB-GCC-UNWINDLIB-COMPILER_RT: "{{[.|\\\n]*}}--rtlib=libgcc requires --unwindlib=libgcc"
 //
 // RUN: %clang -### %s 2>&1 \
+// RUN:     --target=x86_64-pc-windows-msvc -rtlib=compiler-rt --unwindlib=libunwind \
+// RUN:   | FileCheck --check-prefix=MSVC-RTLIB-COMPILER-RT-UNWINDLIB-COMPILER-RT %s
+// MSVC-RTLIB-COMPILER-RT-UNWINDLIB-COMPILER-RT: "{{.*}}clang_rt.builtins-x86_64.lib"
+// MSVC-RTLIB-COMPILER-RT-UNWINDLIB-COMPILER-RT-NOT: "{{.*}}unwind.lib"
+//
+// RUN: %clang -### %s 2>&1 \
 // RUN:     --target=x86_64-w64-mingw32 -rtlib=compiler-rt --unwindlib=libunwind \
 // RUN:     -shared-libgcc \
 // RUN:     --gcc-toolchain="" \