[llvm] [mlir] [OpenMP][IRBuilder] Handle `target ... nowait` when codegen targets host (PR #124720)

[Kareem Ergawy via llvm-commits]

ergawy wrote:

> LLVM Buildbot has detected a new failure on builder `openmp-offload-libc-amdgpu-runtime` running on `omp-vega20-1` while building `llvm,mlir` at step 7 "Add check check-offload".
> 
> Full details are available at: https://lab.llvm.org/buildbot/#/builders/73/builds/12574
> 
> <details>
> <summary>Here is the relevant piece of the build log for the reference</summary>
> 
> ```
> Step 7 (Add check check-offload) failure: test (failure)
> ******************** TEST 'libomptarget :: amdgcn-amd-amdhsa :: mapping/declare_mapper_nested_mappers.cpp' FAILED ********************
> Exit Code: 2
> 
> Command Output (stdout):
> --
> # RUN: at line 1
> /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./bin/clang++ -fopenmp    -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/offload/test -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./lib -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src  -nogpulib -Wl,-rpath,/home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload -Wl,-rpath,/home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -Wl,-rpath,/home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./lib  -fopenmp-targets=amdgcn-amd-amdhsa /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/offload/test/mapping/declare_mapper_nested_mappers.cpp -o /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload/test/amdgcn-amd-amdhsa/mapping/Output/declare_mapper_nested_mappers.cpp.tmp -Xoffload-linker -lc -Xoffload-linker -lm /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./lib/libomptarget.devicertl.a && /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload/test/amdgcn-amd-amdhsa/mapping/Output/declare_mapper_nested_mappers.cpp.tmp | /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./bin/FileCheck /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/offload/test/mapping/declare_mapper_nested_mappers.cpp
> # executed command: /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./bin/clang++ -fopenmp -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/offload/test -I /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./lib -L /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -nogpulib -Wl,-rpath,/home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload -Wl,-rpath,/home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/openmp/runtime/src -Wl,-rpath,/home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./lib -fopenmp-targets=amdgcn-amd-amdhsa /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/offload/test/mapping/declare_mapper_nested_mappers.cpp -o /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload/test/amdgcn-amd-amdhsa/mapping/Output/declare_mapper_nested_mappers.cpp.tmp -Xoffload-linker -lc -Xoffload-linker -lm /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./lib/libomptarget.devicertl.a
> # executed command: /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/runtimes/runtimes-bins/offload/test/amdgcn-amd-amdhsa/mapping/Output/declare_mapper_nested_mappers.cpp.tmp
> # note: command had no output on stdout or stderr
> # error: command failed with exit status: -11
> # executed command: /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./bin/FileCheck /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/offload/test/mapping/declare_mapper_nested_mappers.cpp
> # .---command stderr------------
> # | FileCheck error: '<stdin>' is empty.
> # | FileCheck command line:  /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.build/./bin/FileCheck /home/ompworker/bbot/openmp-offload-libc-amdgpu-runtime/llvm.src/offload/test/mapping/declare_mapper_nested_mappers.cpp
> # `-----------------------------
> # error: command failed with exit status: 2
> 
> --
> 
> ********************
> 
> 
> ```
> 
> </details>

Looking into this one ...

https://github.com/llvm/llvm-project/pull/124720