[clang] 9bbd728 - [HIP] Add libhipcxx to the default header search path (#214279)

[via cfe-commits]

Author: Yaxun (Sam) Liu
Date: 2026-08-06T15:47:49-04:00
New Revision: 9bbd728946da0bc8c0aa757dfec19fe5e893ca45

URL: https://github.com/llvm/llvm-project/commit/9bbd728946da0bc8c0aa757dfec19fe5e893ca45
DIFF: https://github.com/llvm/llvm-project/commit/9bbd728946da0bc8c0aa757dfec19fe5e893ca45.diff

LOG: [HIP] Add libhipcxx to the default header search path (#214279)

libhipcxx provides C++ library support for HIP device code, similar to
libcudacxx for CUDA. CUDA toolchains make libcudacxx available through
the
toolkit include path by default. HIP users should likewise be able to
include libhipcxx headers without an installation-specific include
option.

Add include/libhipcxx from the selected ROCm installation when the
directory exists. It follows the same search order and controls as the
other HIP include paths.

Added: 
    clang/test/Driver/Inputs/rocm/include/libhipcxx/cuda/std/atomic

Modified: 
    clang/docs/ReleaseNotes.md
    clang/lib/Driver/ToolChains/AMDGPU.cpp
    clang/test/Driver/hip-include-path.hip

Removed: 
    


################################################################################
diff  --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md
index 2f13ec59483ee..7976b82b63f6e 100644
--- a/clang/docs/ReleaseNotes.md
+++ b/clang/docs/ReleaseNotes.md
@@ -497,6 +497,12 @@ features cannot lower the translation-unit ABI level;
 
 #### CUDA/HIP Language Changes
 
+- HIP compilations now add the `include/libhipcxx` directory from the selected
+  ROCm installation to the header search path when it exists. This allows
+  libhipcxx headers to be included with paths such as `<cuda/std/atomic>`.
+  The `-nogpuinc` option disables this path together with the other HIP include
+  paths.
+
 #### CUDA Support
 
 - Added `--cuda-emit-nvcc-abi` to emit the NVCC-compatible host registration ABI

diff  --git a/clang/lib/Driver/ToolChains/AMDGPU.cpp b/clang/lib/Driver/ToolChains/AMDGPU.cpp
index 7bce060de0596..9718c621698d8 100644
--- a/clang/lib/Driver/ToolChains/AMDGPU.cpp
+++ b/clang/lib/Driver/ToolChains/AMDGPU.cpp
@@ -593,6 +593,12 @@ void RocmInstallationDetector::AddHIPIncludeArgs(const ArgList &DriverArgs,
 
   CC1Args.push_back("-idirafter");
   CC1Args.push_back(DriverArgs.MakeArgString(getIncludePath()));
+  SmallString<128> LibHipCxxPath(getIncludePath());
+  llvm::sys::path::append(LibHipCxxPath, "libhipcxx");
+  if (D.getVFS().exists(LibHipCxxPath)) {
+    CC1Args.push_back("-idirafter");
+    CC1Args.push_back(DriverArgs.MakeArgString(LibHipCxxPath));
+  }
   if (UsesRuntimeWrapper)
     CC1Args.append({"-include", "__clang_hip_runtime_wrapper.h"});
   if (HasHipStdPar)

diff  --git a/clang/test/Driver/Inputs/rocm/include/libhipcxx/cuda/std/atomic b/clang/test/Driver/Inputs/rocm/include/libhipcxx/cuda/std/atomic
new file mode 100644
index 0000000000000..3dcbff4d2a047
--- /dev/null
+++ b/clang/test/Driver/Inputs/rocm/include/libhipcxx/cuda/std/atomic
@@ -0,0 +1 @@
+// This file makes the mock libhipcxx include directory discoverable.

diff  --git a/clang/test/Driver/hip-include-path.hip b/clang/test/Driver/hip-include-path.hip
index efa91c651c45f..12d37bae092d6 100644
--- a/clang/test/Driver/hip-include-path.hip
+++ b/clang/test/Driver/hip-include-path.hip
@@ -16,10 +16,26 @@
 // RUN:   -std=c++11 --rocm-path=%S/Inputs/rocm --no-offload-inc -nogpulib --offload-inc %s 2>&1 \
 // RUN:   | FileCheck -check-prefixes=COMMON,CLANG,HIP -DRESOURCE_DIR=%clang-resource-dir %s
 
+// RUN: %clang -c -### --target=x86_64-unknown-linux-gnu --cuda-gpu-arch=gfx900 \
+// RUN:   -std=c++11 --rocm-path=%S/Inputs/rocm -nogpulib -nostdinc++ %s 2>&1 \
+// RUN:   | FileCheck -check-prefixes=COMMON,CLANG,HIP -DRESOURCE_DIR=%clang-resource-dir %s
+
+// RUN: %clang -fsyntax-only --target=x86_64-unknown-linux-gnu \
+// RUN:   --cuda-gpu-arch=gfx900 -std=c++11 --rocm-path=%S/Inputs/rocm \
+// RUN:   -nogpulib -nohipwrapperinc %s
+
+// RUN: %clang -c -### --target=x86_64-unknown-linux-gnu --cuda-gpu-arch=gfx900 \
+// RUN:   -std=c++11 --rocm-path=%S/Inputs/rocm-invalid -nogpulib %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=NOLIBHIPCXX %s
+
+// NOLIBHIPCXX: "-idirafter" "{{[^"]*}}Inputs/rocm-invalid/include"
+// NOLIBHIPCXX-NOT: "{{.*}}Inputs/rocm-invalid/include/libhipcxx"
+
 // COMMON-LABEL: "{{[^"]*}}clang{{[^"]*}}" "-cc1"
 // CLANG-SAME: "-internal-isystem" "[[RESOURCE_DIR]]/include/cuda_wrappers"
 // NOCLANG-NOT: "[[RESOURCE_DIR]]/include/cuda_wrappers"
 // HIP-SAME: "-idirafter" "{{[^"]*}}Inputs/rocm/include"
+// HIP-SAME: "-idirafter" "{{[^"]*}}Inputs/rocm/include/libhipcxx"
 // HIP-SAME: "-include" "__clang_hip_runtime_wrapper.h"
 // NOHIP-NOT: "-include" "__clang_hip_runtime_wrapper.h"
 // skip check of standard C++ include path
@@ -31,6 +47,7 @@
 // CLANG-SAME: "-internal-isystem" "[[RESOURCE_DIR]]/include/cuda_wrappers"
 // NOCLANG-NOT: "[[RESOURCE_DIR]]/include/cuda_wrappers"
 // HIP-SAME: "-idirafter" "{{[^"]*}}Inputs/rocm/include"
+// HIP-SAME: "-idirafter" "{{[^"]*}}Inputs/rocm/include/libhipcxx"
 // HIP-SAME: "-include" "__clang_hip_runtime_wrapper.h"
 // NOHIP-NOT: "-include" "__clang_hip_runtime_wrapper.h"
 // skip check of standard C++ include path
@@ -46,6 +63,7 @@
 // ROCM35-NOT: "[[RESOURCE_DIR]]/include/cuda_wrappers"
 // ROCM35-SAME: "-internal-isystem" "[[RESOURCE_DIR]]"
 // ROCM35-SAME: "-idirafter" "{{[^"]*}}Inputs/rocm/include"
+// ROCM35-SAME: "-idirafter" "{{[^"]*}}Inputs/rocm/include/libhipcxx"
 // ROCM35-NOT: "-include" "__clang_hip_runtime_wrapper.h"
 // skip check of standard C++ include path
 // ROCM35-SAME: "-internal-isystem" "[[RESOURCE_DIR]]/include"
@@ -59,3 +77,5 @@
 
 // HOSTINC-LABEL: "{{[^"]*}}clang{{[^"]*}}" "-cc1" "-triple" "amdgcn-amd-amdhsa"
 // HOSTINC: "-internal-externc-isystem" "{{[^"]*}}Inputs/basic_linux_tree/usr/include"
+
+#include <cuda/std/atomic>