[Openmp-commits] [llvm] [openmp] [Offload] Provide a cache file for building OpenMP w/ Flang offloading (PR #178472)

[Joseph Huber via Openmp-commits]

https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/178472

Summary:
This build is more annoying, enables everything required for this
version of the runtime.


>From 58520b7634faaa2cc7ede58637d60876653ae3bb Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Wed, 28 Jan 2026 11:22:27 -0600
Subject: [PATCH] [Offload] Provide a cache file for building OpenMP w/ Flang
 offloading

Summary:
This build is more annoying, enables everything required for this
version of the runtime.
---
 offload/cmake/caches/FlangOffload.cmake | 13 +++++++++++++
 openmp/docs/Building.md                 |  2 ++
 2 files changed, 15 insertions(+)
 create mode 100644 offload/cmake/caches/FlangOffload.cmake

diff --git a/offload/cmake/caches/FlangOffload.cmake b/offload/cmake/caches/FlangOffload.cmake
new file mode 100644
index 0000000000000..ed75df6bb7e13
--- /dev/null
+++ b/offload/cmake/caches/FlangOffload.cmake
@@ -0,0 +1,13 @@
+set(LLVM_ENABLE_PROJECTS "clang;flang;mlir;clang-tools-extra;lld" CACHE STRING "")
+set(LLVM_ENABLE_RUNTIMES "compiler-rt;flang-rt;libunwind;libcxx;libcxxabi;openmp;offload" CACHE STRING "")
+set(LLVM_ENABLE_PER_TARGET_RUNTIME_DIR ON CACHE BOOL "")
+
+set(LLVM_RUNTIME_TARGETS default;amdgcn-amd-amdhsa;nvptx64-nvidia-cuda CACHE STRING "") 
+set(RUNTIMES_nvptx64-nvidia-cuda_CACHE_FILES "${CMAKE_SOURCE_DIR}/../libcxx/cmake/caches/NVPTX.cmake" CACHE STRING "")
+set(RUNTIMES_amdgcn-amd-amdhsa_CACHE_FILES "${CMAKE_SOURCE_DIR}/../libcxx/cmake/caches/AMDGPU.cmake" CACHE STRING "")
+set(RUNTIMES_nvptx64-nvidia-cuda_LLVM_ENABLE_RUNTIMES "compiler-rt;libc;openmp;libcxx;libcxxabi;flang-rt" CACHE STRING "")
+set(RUNTIMES_amdgcn-amd-amdhsa_LLVM_ENABLE_RUNTIMES "compiler-rt;libc;openmp;libcxx;libcxxabi;flang-rt" CACHE STRING "")
+set(RUNTIMES_nvptx64-nvidia-cuda_FLANG_RT_LIBC_PROVIDER llvm CACHE STRING "")
+set(RUNTIMES_nvptx64-nvidia-cuda_FLANG_RT_LIBCXX_PROVIDER llvm CACHE STRING "")
+set(RUNTIMES_amdgcn-amd-amdhsa_FLANG_RT_LIBC_PROVIDER llvm CACHE STRING "")
+set(RUNTIMES_amdgcn-amd-amdhsa_FLANG_RT_LIBCXX_PROVIDER llvm CACHE STRING "")
diff --git a/openmp/docs/Building.md b/openmp/docs/Building.md
index 15d39d855b158..c023a6e6717df 100644
--- a/openmp/docs/Building.md
+++ b/openmp/docs/Building.md
@@ -194,6 +194,8 @@ cmake ../llvm -G Ninja                       \
     -DCMAKE_INSTALL_PREFIX=<PATH>
 ```
 
+Additionally, the `FlangOffload.cmake` file is provided for users that wish to
+build a complete Fortran offloading toolchain.
 
 ## Building on Windows