[OpenMP] DO NOT MERGE. This fixes --opaque-offload-linker and temporarily sets default to --opaque-offload-linker for testing.

Author: gregrodgers

clang/include/clang/Driver/Options.td

@@ -3822,10 +3822,17 @@ defm openmp_optimistic_collapse : BoolFOption<"openmp-optimistic-collapse",
   NegFlag<SetFalse>, BothFlags<[NoArgumentUnused, HelpHidden], []>>;
 def static_openmp: Flag<["-"], "static-openmp">,
   HelpText<"Use the static host OpenMP runtime while linking.">;
-def opaque_offload_linker : Flag<["--"], "opaque-offload-linker">, Visibility<[ClangOption, CC1Option]>, Group<f_Group>,
-  HelpText<"Build/link omp offload binary, construct opaque cmd list instead of single clang-linker-wrapper cmd.">;
-def no_opaque_offload_linker : Flag<["--"], "no-opaque-offload-linker">, Visibility<[ClangOption, CC1Option]>, Group<f_Group>,
-  HelpText<"Build/link omp offload binary, using single clang-linker-wrapper cmd.">;
+def opaque_offload_linker
+    : Flag<["--"], "opaque-offload-linker">,
+      Visibility<[ClangOption, FlangOption]>,
+      Group<f_Group>,
+      HelpText<"Build/link omp offload binary, construct opaque cmd list "
+               "instead of single clang-linker-wrapper cmd.">;
+def no_opaque_offload_linker : Flag<["--"], "no-opaque-offload-linker">,
+                               Visibility<[ClangOption, FlangOption]>,
+                               Group<f_Group>,
+                               HelpText<"Build/link omp offload binary, using "
+                                        "single clang-linker-wrapper cmd.">;
 def fopenmp_new_driver : Flag<["-"], "fopenmp-new-driver">, Flags<[HelpHidden]>,
   HelpText<"Use the new driver for OpenMP offloading.">;
 def fno_openmp_new_driver : Flag<["-"], "fno-openmp-new-driver">,

clang/lib/Driver/ToolChains/Clang.cpp

@@ -9384,6 +9384,24 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
                                  const InputInfoList &Inputs,
                                  const ArgList &Args,
                                  const char *LinkingOutput) const {
+  bool isAMDGPU = false;
+  auto offloadTC = C.getOffloadToolChains(Action::OFK_OpenMP);
+  const auto OpenMPTCs = llvm::make_range(offloadTC.first, offloadTC.second);
+  const ToolChain *OTC;
+  for (auto &I : OpenMPTCs) {
+    OTC = I.second;
+    if (OTC->getTriple().isAMDGPU()) {
+      isAMDGPU = true;
+      break;
+    }
+  }
+  if (isAMDGPU && Args.hasFlag(options::OPT_opaque_offload_linker,
+                               options::OPT_no_opaque_offload_linker, true)) {
+    ConstructOpaqueJob(C, JA, Output, Inputs, Args, OTC->getTriple(),
+                       LinkingOutput);
+    return;
+  }
+
   using namespace options;
 
   // A list of permitted options that will be forwarded to the embedded device