[Clang][Driver] Don't pass -mllvm to the linker for non-LLVM offloading toolchains (#153272)

When determining what arguments to pass to `clang-linker-wrapper` as
device linker args, don't forward `-mllvm` args if the offloading
toolchain doesn't have native LLVM support.

I saw this when working with SPIR-V, we were trying to pass `-mllvm` to
`spirv-link`.

Signed-off-by: Sarnie, Nick <[email protected]>

Author: sarnex

clang/lib/Driver/ToolChains/Clang.cpp

@@ -9117,10 +9117,16 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
       OPT_flto_partitions_EQ,
       OPT_flto_EQ};
   const llvm::DenseSet<unsigned> LinkerOptions{OPT_mllvm, OPT_Zlinker_input};
-  auto ShouldForward = [&](const llvm::DenseSet<unsigned> &Set, Arg *A) {
-    return Set.contains(A->getOption().getID()) ||
-           (A->getOption().getGroup().isValid() &&
-            Set.contains(A->getOption().getGroup().getID()));
+  auto ShouldForwardForToolChain = [&](Arg *A, const ToolChain &TC) {
+    // Don't forward -mllvm to toolchains that don't support LLVM.
+    return TC.HasNativeLLVMSupport() || A->getOption().getID() != OPT_mllvm;
+  };
+  auto ShouldForward = [&](const llvm::DenseSet<unsigned> &Set, Arg *A,
+                           const ToolChain &TC) {
+    return (Set.contains(A->getOption().getID()) ||
+            (A->getOption().getGroup().isValid() &&
+             Set.contains(A->getOption().getGroup().getID()))) &&
+           ShouldForwardForToolChain(A, TC);
   };
 
   ArgStringList CmdArgs;
@@ -9139,9 +9145,9 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
       for (Arg *A : ToolChainArgs) {
         if (A->getOption().matches(OPT_Zlinker_input))
           LinkerArgs.emplace_back(A->getValue());
-        else if (ShouldForward(CompilerOptions, A))
+        else if (ShouldForward(CompilerOptions, A, *TC))
           A->render(Args, CompilerArgs);
-        else if (ShouldForward(LinkerOptions, A))
+        else if (ShouldForward(LinkerOptions, A, *TC))
           A->render(Args, LinkerArgs);
       }
 

clang/test/Driver/spirv-openmp-toolchain.c

@@ -60,3 +60,12 @@
 // RUN:        --libomptarget-spirv-bc-path=%t/ -nogpulib %s 2>&1 \
 // RUN: | FileCheck %s --check-prefix=CHECK-OFFLOAD-ARCH-ERROR
 // CHECK-OFFLOAD-ARCH-ERROR: error: failed to deduce triple for target architecture 'spirv64-intel'; specify the triple using '-fopenmp-targets' and '-Xopenmp-target' instead
+
+// RUN: %clang -mllvm --spirv-ext=+SPV_INTEL_function_pointers -### --target=x86_64-unknown-linux-gnu -fopenmp=libomp -fopenmp-targets=spirv64-intel \
+// RUN:        -nogpulib %s 2>&1 \
+// RUN: | FileCheck %s --check-prefix=CHECK-LINKER-ARG
+// CHECK-LINKER-ARG: clang-linker-wrapper
+// CHECK-LINKER-ARG-NOT: --device-linker=spirv64
+// CHECK-LINKER-ARG-NOT: -mllvm
+// CHECK-LINKER-ARG-NOT: --spirv-ext=+SPV_INTEL_function_pointers
+// CHECK-LINKER-ARG: --linker-path