[Clang] Only link C device libraries by default for OpenMP (#151239)

Summary: We link these implicitly for OpenMP because it's the canonical implementation of those C language features. This was inhereted by HIP and ended up with these resolving functions. There are some useful functions in here, but this can be problematic as it could potentially override functions intended to be provided by the ROCm device libraries. Additionally the HIP runtime does not currently provide the handling for the RPC server required to run the host resources so those just segfault.

Author: jhuber6

clang/lib/Driver/ToolChains/Clang.cpp

@@ -9214,8 +9214,9 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
  options::OPT_nogpulibc)) {
  forAllAssociatedToolChains(C, JA, getToolChain(), [&](const ToolChain &TC) {
  // The device C library is only available for NVPTX and AMDGPU targets
- // currently.
- if (!TC.getTriple().isNVPTX() && !TC.getTriple().isAMDGPU())
+ // and we only link it by default for OpenMP currently.
+ if ((!TC.getTriple().isNVPTX() && !TC.getTriple().isAMDGPU()) ||
+ !JA.isHostOffloading(Action::OFK_OpenMP))
  return;
  bool HasLibC = TC.getStdlibIncludePath().has_value();
  if (HasLibC) {

clang/test/Driver/gpu-libc-headers.c

@@ -0,0 +1,32 @@
+// RUN: %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx90a --sysroot=%S/Inputs/basic_gpu_tree \
+// RUN: -ccc-install-dir %S/Inputs/basic_gpu_tree/bin -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-AMDGPU
+// RUN: %clang -### --target=nvptx64-nvidia-cuda -march=sm_89 --sysroot=%S/Inputs/basic_gpu_tree \
+// RUN: -ccc-install-dir %S/Inputs/basic_gpu_tree/bin -nogpulib %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-NVPTX
+// CHECK-HEADERS-AMDGPU: "-cc1"{{.*}}"-isysroot"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}amdgcn-amd-amdhsa"
+// CHECK-HEADERS-NVPTX: "-cc1"{{.*}}"-isysroot"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}nvptx64-nvidia-cuda"
+
+// RUN: %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
+// RUN: -nogpuinc %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-DISABLED
+// RUN: %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
+// RUN: -nostdinc %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-DISABLED
+// RUN: %clang -### --target=amdgcn-amd-amdhsa -mcpu=gfx1030 -nogpulib \
+// RUN: -nobuiltininc %s 2>&1 | FileCheck %s --check-prefix=CHECK-HEADERS-DISABLED
+// CHECK-HEADERS-DISABLED-NOT: "-cc1"{{.*}}"-internal-isystem" "{{.*}}include{{.*}}gpu-none-llvm"
+
+
+// RUN: %clang -### -fopenmp=libomp --target=x86_64-unknown-linux-gnu \
+// RUN: --offload-arch=gfx908 --rocm-path=%S/Inputs/rocm --sysroot=%S/Inputs/basic_gpu_tree \
+// RUN: -ccc-install-dir %S/Inputs/basic_gpu_tree/bin %s 2>&1 | FileCheck %s --check-prefix=OPENMP-AMDGPU
+// OPENMP-AMDGPU: clang-linker-wrapper{{.*}}"--device-linker=amdgcn-amd-amdhsa=-lc"
+// RUN: %clang -### -fopenmp=libomp --target=x86_64-unknown-linux-gnu -foffload-lto \
+// RUN: --offload-arch=sm_52 --cuda-path=%S/Inputs/CUDA_111/usr/local/cuda --sysroot=%S/Inputs/basic_gpu_tree \
+// RUN: -ccc-install-dir %S/Inputs/basic_gpu_tree/bin %s 2>&1 | FileCheck %s --check-prefix=OPENMP-NVPTX
+// OPENMP-NVPTX: clang-linker-wrapper{{.*}}"--device-linker=nvptx64-nvidia-cuda=-lc"
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu --offload-arch=gfx908 \
+// RUN: --offload-new-driver --rocm-path=%S/Inputs/rocm --sysroot=%S/Inputs/basic_gpu_tree \
+// RUN: -ccc-install-dir %S/Inputs/basic_gpu_tree/bin -x hip %s 2>&1 | FileCheck %s --check-prefix=HIP
+// HIP-NOT: "--device-linker=amdgcn-amd-amdhsa=-lc"
+// RUN: %clang -### --target=x86_64-unknown-linux-gnu -fgpu-rdc --offload-arch=sm_52 \
+// RUN: --cuda-path=%S/Inputs/CUDA_111/usr/local/cuda --sysroot=%S/Inputs/basic_gpu_tree \
+// RUN: -ccc-install-dir %S/Inputs/basic_gpu_tree/bin -x cuda %s 2>&1 | FileCheck %s --check-prefix=CUDA
+// CUDA-NOT: "--device-linker=nvptx64-nvidia-cuda=-lc"