Failure in building `offload-tblgen/APIGen.cpp` with parallel build

[Crivella]

LLVM version: 20.1.0

During a 3 stage build using CMake + Make , following a parallel build (make -j 8 VERBOSE=1)
I encountered the following error during the build of the offload-tblgen offload tool

cd /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm.obj.3/runtimes/runtimes-bins/offload/tools/offload-tblgen && /tmp/eb-k5n5152l/tmprub7h5td/rpath_wrappers/clangxx_wrapper/clang++ --target=x86_64-unknown-linux-gnu -DLLVM_BUILD_STATIC -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include -I/home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm.obj.3/include -isystem /home/crivella/.local/easybuild/software/zlib/1.3.1/include --gcc-install-dir=/home/crivella/.local/easybuild/software/GCCcore/13.3.0/lib/gcc/x86_64-pc-linux-gnu/13.3.0 -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wstring-conversion -ffunction-sections -fdata-sections -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -MD -MT offload/tools/offload-tblgen/CMakeFiles/offload-tblgen.dir/APIGen.cpp.o -MF CMakeFiles/offload-tblgen.dir/APIGen.cpp.o.d -o CMakeFiles/offload-tblgen.dir/APIGen.cpp.o -c /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/offload/tools/offload-tblgen/APIGen.cpp

In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/offload/tools/offload-tblgen/APIGen.cpp:14:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/StringExtras.h:17:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/APSInt.h:18:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/APInt.h:19:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/Support/MathExtras.h:16:
/home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/bit.h:18:10: fatal error: 'cstdint' file not found
   18 | #include <cstdint>
      |          ^~~~~~~~~

After attempting to re-execute the build in serial make -j 1 VERBOSE=1 to try and debug the errors 1 by 1 the build actually succeeded.

Could there be a missing dependency for the offload tools that can cause parallel build to fails if the dep is not resolved before the tool build?

[llvmbot]

@llvm/issue-subscribers-offload

Author: Davide Grassano (Crivella)

During a 3 stage build using CMake + Make , following a parallel build (`make -j 8 VERBOSE=1`) I encountered the following error during the build of the `offload-tblgen` offload tool

cd /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm.obj.3/runtimes/runtimes-bins/offload/tools/offload-tblgen && /tmp/eb-k5n5152l/tmprub7h5td/rpath_wrappers/clangxx_wrapper/clang++ --target=x86_64-unknown-linux-gnu -DLLVM_BUILD_STATIC -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include -I/home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm.obj.3/include -isystem /home/crivella/.local/easybuild/software/zlib/1.3.1/include --gcc-install-dir=/home/crivella/.local/easybuild/software/GCCcore/13.3.0/lib/gcc/x86_64-pc-linux-gnu/13.3.0 -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wstring-conversion -ffunction-sections -fdata-sections -O3 -DNDEBUG -std=c++17  -fno-exceptions -funwind-tables -MD -MT offload/tools/offload-tblgen/CMakeFiles/offload-tblgen.dir/APIGen.cpp.o -MF CMakeFiles/offload-tblgen.dir/APIGen.cpp.o.d -o CMakeFiles/offload-tblgen.dir/APIGen.cpp.o -c /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/offload/tools/offload-tblgen/APIGen.cpp

In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/offload/tools/offload-tblgen/APIGen.cpp:14:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/StringExtras.h:17:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/APSInt.h:18:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/APInt.h:19:
In file included from /home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/Support/MathExtras.h:16:
/home/crivella/.local/easybuild/build/LLVM/20.1.0/system-system/llvm-project-20.1.0.src/llvm/include/llvm/ADT/bit.h:18:10: fatal error: 'cstdint' file not found
   18 | #include <cstdint>
      |          ^~~~~~~~~

After attempting to re-execute the build in serial make -j 1 VERBOSE=1 to try and debug the errors 1 by 1 the build actually succeeded.

Could there be a missing dependency for the offload tools that can cause parallel build to fails if the dep is not resolved before the tool build?

[jhuber6]

Likely a difference in how ninja and make handle the dependencies. Most likely requires adding a depends statement somewhere. @callumfare is off right now, but if you need an easy solution I would suggest using ninja instead.