[libc] Forward CUDA options to the runtimes invocation of `libc`

Some configurations may require `-DCUDAToolkit_ROOT` to find CUDA
properly. This is currently not forwarded to the CMake invocation. This
patch adds a prefix so it will be visible when the runtimes build is
started.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D147582

diff --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
index f4c697e..cc5f530 100644 (file)
--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
@@ -183,6 +183,10 @@ foreach(entry ${runtimes})
   if(canon_name STREQUAL "LIBC")
     list(APPEND prefixes "LLVM_LIBC")
     list(APPEND prefixes "LIBC_")
+    # The `libc` project may require '-DCUDAToolkit_ROOT' in GPU mode.
+    if(LIBC_GPU_BUILD OR LIBC_GPU_ARCHITECTURES)
+      list(APPEND prefixes "CUDA")
+    endif()
   endif()
 
   string(FIND ${projName} "lib" LIB_IDX)