[llvm] [offload] Give libLLVMOffloadKernel a working rpath in a shared-library build (PR #218629)

[Larry Meadows via llvm-commits]

https://github.com/lfmeadow created https://github.com/llvm/llvm-project/pull/218629

libLLVMOffloadKernel links against libLLVMOffload and finds it through an
`$ORIGIN` rpath, which resolves only if the two land in the same directory.
`add_llvm_library` puts the kernel library in LLVM's `lib` while libLLVMOffload
is in `lib/<triple>`, so every test that loads it fails at startup with

    libLLVMOffload.so: cannot open shared object file: No such file or directory

Set `LIBRARY_OUTPUT_DIRECTORY` the way `RUNTIME_OUTPUT_DIRECTORY` already is.

## Testing

Based on `main` at 65d6b72e5e12. CMake only, no test changes. With shared
libraries and `LLVM_ENABLE_RUNTIMES=...;openmp;offload`, the kernel library now
lands beside libLLVMOffload and loads.


>From 8b74fdeed62c8ed39686244f5a239ffaab8f081e Mon Sep 17 00:00:00 2001
From: Larry Meadows <Lawrence.Meadows at amd.com>
Date: Fri, 21 Aug 2026 22:16:32 -0500
Subject: [PATCH] [offload] Give libLLVMOffloadKernel a working rpath in a
 shared-library build

libLLVMOffloadKernel links against libLLVMOffload and finds it through an
$ORIGIN rpath, which resolves only if the two land in the same directory. Set
LIBRARY_OUTPUT_DIRECTORY the way RUNTIME_OUTPUT_DIRECTORY already is.

Co-authored-by: Cursor <cursoragent at cursor.com>
---
 offload/languages/kernel/CMakeLists.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/offload/languages/kernel/CMakeLists.txt b/offload/languages/kernel/CMakeLists.txt
index ff0bb81c7f017..e2fef39a1b041 100644
--- a/offload/languages/kernel/CMakeLists.txt
+++ b/offload/languages/kernel/CMakeLists.txt
@@ -66,6 +66,7 @@ target_compile_definitions(LLVMOffloadKernel PRIVATE
 
 set_target_properties(LLVMOffloadKernel PROPERTIES
                       RUNTIME_OUTPUT_DIRECTORY "${LLVM_LIBRARY_OUTPUT_INTDIR}/${OFFLOAD_TARGET_SUBDIR}"
+                      LIBRARY_OUTPUT_DIRECTORY "${LLVM_LIBRARY_OUTPUT_INTDIR}/${OFFLOAD_TARGET_SUBDIR}"
                       POSITION_INDEPENDENT_CODE ON
                       INSTALL_RPATH "$ORIGIN"
                       BUILD_RPATH "$ORIGIN:${CMAKE_CURRENT_BINARY_DIR}/..")