[libomptarget][amdcgn] Only add opt/llvm-link dependency if TARGET is…

… available

In some build configurations, the target we depend on is not available for declaring the build dependency.
We only need to declare the build dependency, if the build target is available in the same build.

Fixes the issue raised in https://reviews.llvm.org/D107156#2969862
This patch should go into release/13 together with D108404

Differential Revision: https://reviews.llvm.org/D108868

(cherry picked from commit 5ea1c37)

llvm/runtimes/CMakeLists.txt

@@ -350,9 +350,14 @@ if(runtimes)
   # Create a runtimes target that uses this file as its top-level CMake file.
   # The runtimes target is a configuration of all the runtime libraries
   # together in a single CMake invocaiton.
+  set(extra_deps "")
   if("openmp" IN_LIST LLVM_ENABLE_RUNTIMES)
-    message(STATUS "Adding dependencies opt llvm-link")
-    set(extra_deps opt llvm-link)
+    if(TARGET opt)
+      list(APPEND extra_deps opt)
+    endif()
+    if(TARGET llvm-link)
+      list(APPEND extra_deps llvm-link)
+    endif()
   endif()
   if(NOT LLVM_RUNTIME_TARGETS)
     runtime_default_target(

openmp/libomptarget/deviceRTLs/amdgcn/CMakeLists.txt

@@ -149,6 +149,14 @@ endmacro()
 
 set(libname "omptarget-amdgcn")
 
+set(toolchain_deps "")
+if(TARGET llvm-link)
+  list(APPEND toolchain_deps llvm-link)
+endif()
+if(TARGET opt)
+  list(APPEND toolchain_deps opt)
+endif()
+
 foreach(mcpu ${mcpus})
   set(bc_files)
   add_cuda_bc_library(${cuda_sources})
@@ -157,7 +165,7 @@ foreach(mcpu ${mcpus})
   add_custom_command(
     OUTPUT ${bc_libname}
     COMMAND ${LINK_TOOL} ${bc_files} | ${OPT_TOOL} --always-inline -o ${OUTPUTDIR}/${bc_libname}
-    DEPENDS ${bc_files} llvm-link opt)
+    DEPENDS ${bc_files} ${toolchain_deps})
 
   add_custom_target(lib${libname}-${mcpu} ALL DEPENDS ${bc_libname})