Remove old method for passing C libraries.

Author: jhuber6

clang/lib/Driver/ToolChains/Clang.cpp

@@ -9111,6 +9111,11 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
     A->claim();
   }
 
+  // If we disable the GPU C library support it needs to be forwarded to the
+  // link job.
+  if (!Args.hasFlag(options::OPT_gpulibc, options::OPT_nogpulibc, true))
+    CmdArgs.push_back("--device-linker=-nolibc");
+
   // Add the linker arguments to be forwarded by the wrapper.
   CmdArgs.push_back(Args.MakeArgString(Twine("--linker-path=") +
                                        LinkCommand->getExecutable()));

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -1161,42 +1161,6 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
   }
 }
 
-/// Adds the '-lcgpu' and '-lmgpu' libraries to the compilation to include the
-/// LLVM C library for GPUs.
-static void addOpenMPDeviceLibC(const Compilation &C, const ArgList &Args,
-                                ArgStringList &CmdArgs) {
-  if (Args.hasArg(options::OPT_nogpulib) || Args.hasArg(options::OPT_nolibc))
-    return;
-
-  // Check the resource directory for the LLVM libc GPU declarations. If it's
-  // found we can assume that LLVM was built with support for the GPU libc.
-  SmallString<256> LibCDecls(C.getDriver().ResourceDir);
-  llvm::sys::path::append(LibCDecls, "include", "llvm_libc_wrappers",
-                          "llvm-libc-decls");
-  bool HasLibC = llvm::sys::fs::exists(LibCDecls) &&
-                 llvm::sys::fs::is_directory(LibCDecls);
-  if (!Args.hasFlag(options::OPT_gpulibc, options::OPT_nogpulibc, HasLibC))
-    return;
-
-  SmallVector<const ToolChain *> ToolChains;
-  auto TCRange = C.getOffloadToolChains(Action::OFK_OpenMP);
-  for (auto TI = TCRange.first, TE = TCRange.second; TI != TE; ++TI)
-    ToolChains.push_back(TI->second);
-
-  if (llvm::any_of(ToolChains, [](const ToolChain *TC) {
-        return TC->getTriple().isAMDGPU();
-      })) {
-    CmdArgs.push_back("-lcgpu-amdgpu");
-    CmdArgs.push_back("-lmgpu-amdgpu");
-  }
-  if (llvm::any_of(ToolChains, [](const ToolChain *TC) {
-        return TC->getTriple().isNVPTX();
-      })) {
-    CmdArgs.push_back("-lcgpu-nvptx");
-    CmdArgs.push_back("-lmgpu-nvptx");
-  }
-}
-
 void tools::addOpenMPRuntimeLibraryPath(const ToolChain &TC,
                                         const ArgList &Args,
                                         ArgStringList &CmdArgs) {
@@ -1269,9 +1233,6 @@ bool tools::addOpenMPRuntime(const Compilation &C, ArgStringList &CmdArgs,
   if (IsOffloadingHost && !Args.hasArg(options::OPT_nogpulib))
     CmdArgs.push_back("-lomptarget.devicertl");
 
-  if (IsOffloadingHost)
-    addOpenMPDeviceLibC(C, Args, CmdArgs);
-
   addArchSpecificRPath(TC, Args, CmdArgs);
 
   addOpenMPRuntimeLibraryPath(TC, Args, CmdArgs);

clang/test/Driver/openmp-offload-gpu.c

@@ -372,33 +372,9 @@
 // XARCH-DEVICE: "-cc1" "-triple" "nvptx64-nvidia-cuda"{{.*}}"-O3"
 // XARCH-DEVICE-NOT: "-cc1" "-triple" "x86_64-unknown-linux-gnu"{{.*}}"-O3"
 
-//
-// Check that `-gpulibc` includes the LLVM C libraries for the GPU.
-//
-// RUN:   %clang -### --target=x86_64-unknown-linux-gnu -fopenmp=libomp \
-// RUN:      --libomptarget-nvptx-bc-path=%S/Inputs/libomptarget/libomptarget-nvptx-test.bc \
-// RUN:      --libomptarget-amdgpu-bc-path=%S/Inputs/hip_dev_lib/libomptarget-amdgpu-gfx803.bc \
-// RUN:      --cuda-path=%S/Inputs/CUDA_102/usr/local/cuda \
-// RUN:      --rocm-path=%S/Inputs/rocm \
-// RUN:      --offload-arch=sm_52,gfx803 -gpulibc -nogpuinc %s 2>&1 \
-// RUN:   | FileCheck --check-prefix=LIBC-GPU %s
-// RUN:   %clang -### --target=x86_64-unknown-linux-gnu -fopenmp=libomp \
-// RUN:      --libomptarget-nvptx-bc-path=%S/Inputs/libomptarget/libomptarget-nvptx-test.bc \
-// RUN:      --libomptarget-amdgpu-bc-path=%S/Inputs/hip_dev_lib/libomptarget-amdgpu-gfx803.bc \
-// RUN:      --cuda-path=%S/Inputs/CUDA_102/usr/local/cuda \
-// RUN:      --rocm-path=%S/Inputs/rocm \
-// RUN:      -Xopenmp-target=nvptx64-nvidia-cuda -march=sm_52 \
-// RUN:      -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx803 \
-// RUN:      -fopenmp-targets=nvptx64-nvidia-cuda,amdgcn-amd-amdhsa -gpulibc -nogpuinc %s 2>&1 \
-// RUN:   | FileCheck --check-prefix=LIBC-GPU %s
-// LIBC-GPU-DAG: "-lcgpu-amdgpu"
-// LIBC-GPU-DAG: "-lmgpu-amdgpu"
-// LIBC-GPU-DAG: "-lcgpu-nvptx"
-// LIBC-GPU-DAG: "-lmgpu-nvptx"
-
 // RUN:   %clang -### --target=x86_64-unknown-linux-gnu -fopenmp=libomp \
 // RUN:      --libomptarget-nvptx-bc-path=%S/Inputs/libomptarget/libomptarget-nvptx-test.bc \
 // RUN:      --cuda-path=%S/Inputs/CUDA_102/usr/local/cuda \
 // RUN:      --offload-arch=sm_52 -nogpulibc -nogpuinc %s 2>&1 \
-// RUN:   | FileCheck --check-prefix=NO-LIBC-GPU %s
-// NO-LIBC-GPU-NOT: -lmgpu{{.*}}-lcgpu
+// RUN:   | FileCheck --check-prefix=LIBC-GPU %s
+// LIBC-GPU: clang-linker-wrapper{{.*}}"--device-linker=-nolibc"