[Offload] Fix missing dependencies in Offload API generation

[callumfare]

Thanks to @RossBrunton for spotting this.

We attempt to clang-format the generated Offload header files, but if clang-format isn't available we just copy the generated files instead. That fallback path was missing the correct dependencies.

Fixes #142756

[llvmbot]

@llvm/pr-subscribers-offload

Author: Callum Fare (callumfare)

Changes

Thanks to @RossBrunton for spotting this.

We attempt to clang-format the generated Offload header files, but if clang-format isn't available we just copy the generated files instead. That fallback path was missing the correct dependencies.

Fixes #142756

---

Full diff: https://github.com/llvm/llvm-project/pull/142776.diff

1 Files Affected:

• (modified) offload/liboffload/API/CMakeLists.txt (+2)

diff --git a/offload/liboffload/API/CMakeLists.txt b/offload/liboffload/API/CMakeLists.txt
index cf6e132aa57a9..216710faa84f6 100644
--- a/offload/liboffload/API/CMakeLists.txt
+++ b/offload/liboffload/API/CMakeLists.txt
@@ -42,5 +42,7 @@ else()
             COMMAND ${CMAKE_COMMAND} -E copy_if_different generated/${file}.gen ${CMAKE_CURRENT_BINARY_DIR}/${file}
             DEPENDS generated/${file}.gen
         )
+        add_custom_target(OffloadAPI.${file} DEPENDS ${file})
+        add_dependencies(OffloadAPI OffloadAPI.${file})
     endforeach()
 endif()

[jhuber6]

Didn't my original patch have that? Guess I didn't notice it missing.

[kparzysz]

The generation fails if the "generated" and "include" subdirectories are missing.

runtimes/runtimes-bins/offload/plugins-nextgen/common/include
runtimes/runtimes-bins/offload/liboffload/API/generated

[callumfare]

@kparzysz I don't see any failures when building with a completely clean build directory. Could you share the build log where you're getting those failures?

[kparzysz]

Here's the error

[ 62%] Building include/OffloadErrcodes.inc...
[ 62%] Linking CXX static library /work/kparzysz/git/llvm.org/b/x86/lib/amdgcn-amd-amdhsa/libompdevice.a
[ 62%] Built target RTScudoCUnitTest.x86_64
[ 62%] Building CXX object openmp/runtime/src/CMakeFiles/omp.dir/kmp_alloc.cpp.o/work/kparzysz/git/llvm.org/b/x86/bin/offload-tblgen: error opening /work/kparzysz/git/llvm.org/b/x86/runtimes/runtimes-bins/offload/plugins-nextgen/common/include/OffloadErrcodes.inc: No such file or directory
make[5]: *** [offload/plugins-nextgen/common/CMakeFiles/PluginErrcodes.dir/build.make:121: offload/plugins-nextgen/common/include/OffloadErrcodes.inc] Error 1
make[5]: Leaving directory '/work2/kparzysz/git/llvm.org/b/x86/runtimes/runtimes-bins'
make[4]: *** [CMakeFiles/Makefile2:26763: offload/plugins-nextgen/common/CMakeFiles/PluginErrcodes.dir/all] Error 2
make[4]: *** Waiting for unfinished jobs....

My cmake command was

cmake -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_ASSERTIONS=ON -DLLVM_LIT_ARGS='-sv -j64' -DCMAKE_INSTALL_PREFIX=/work/kparzysz/c/org -DCMAKE_BUILD_TYPE=Release -DCLANG_DEFAULT_LINKER=lld -DLLVM_BUILD_TESTS=ON -DLLVM_INCLUDE_TESTS=ON -DCLANG_INCLUDE_TESTS=ON -DLLVM_TARGETS_TO_BUILD=all -DLLVM_ENABLE_RUNTIMES='openmp;offload;compiler-rt;libcxx;libcxxabi;libunwind' -DLLVM_ENABLE_PROJECTS='bolt;clang;clang-tools-extra;flang;lld;lldb;mlir;polly;pstl' -DBUILD_SHARED_LIBS=ON -DLIBOMPTARGET_PLUGINS_TO_BUILD='amdgpu;host' -DCLANG_DEFAULT_PIE_ON_LINUX=OFF -DLIBOMP_OMPT_SUPPORT=OFF -DLLVM_OMIT_DAGISEL_COMMENTS=OFF ../../llvm

[kparzysz]

Manually creating the two directories fixes the problem: make all install completes successfully.

[callumfare]

Thanks, it could be a difference between Ninja and Makefile, I'll investigate

[kparzysz]

This happens when I start with an empty directory as the build tree. Once it's populated with make files and subdirectories (with these two created by hand), everything works in all subsequent builds.

[callumfare]

@kparzysz I was able to reproduce this failure, it should be fixed by this PR #142817