dpclang fails to build with custom installed L0 in parallel to system installed one

[dvrogozh]

With v7.0.1 on Linux (Ubuntu 24.04). Note that issue can't be reproduced on b73d26e (latest sycl branch head as of 8/27/2026) - I explain why in the #23045 (comment).

Consider that system has outdated system-wide installation of L0, for example, on PVC system with LTS 2350 driver set:

$ find /usr/lib/x86_64-linux-gnu/ -name libze_loader.so.1.*
/usr/lib/x86_64-linux-gnu/libze_loader.so.1.24.0
$ pkg-config --modversion level-zero
1.24.0

This version is too old to build dpclang. Thus user can opt-in to build dpclang against custom installation of L0, so he does:

git clone https://github.com/oneapi-src/level-zero.git && cd level-zero
git checkout v1.33.1
cmake -B _build -S . -G Ninja \
            -DCMAKE_BUILD_TYPE=Release \
            -DCMAKE_INSTALL_PREFIX=$HOME/_install
cmake --build _build
cmake --install _build

Note that user installs L0 into custom local directory $HOME/_install. In this case build of the dpclang will fail:

$ export PKG_CONFIG_PATH=$HOME/_install/lib/pkgconfig/
$ export LD_LIBRARY_PATH=$HOME/_install/lib:$LD_LIBRARY_PATH
$ cmake -B _build -S llvm -G Ninja \
            -DCMAKE_BUILD_TYPE=Release \
            -DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX \
            -DBUILD_SHARED_LIBS=ON \
            -DLLVM_BUILD_TOOLS=ON \
            -DLLVM_ENABLE_ASSERTIONS=ON \
            -DLLVM_ENABLE_DOXYGEN=OFF \
            -DLLVM_ENABLE_LLD=OFF \
            -DLLVM_ENABLE_PROJECTS='clang;sycl;llvm-spirv;opencl;xpti;xptifw;compiler-rt;libdevice;sycl-jit' \
            -DLLVM_ENABLE_RTTI=ON \
            -DLLVM_ENABLE_SPHINX=OFF \
            -DLLVM_ENABLE_ZSTD=ON \
            -DLLVM_EXTERNAL_PROJECTS='sycl;llvm-spirv;opencl;xpti;xptifw;compiler-rt;libdevice;sycl-jit' \
            -DLLVM_SPIRV_ENABLE_LIBSPIRV_DIS=OFF \
            -DLLVM_TARGETS_TO_BUILD='host;SPIRV' \
            -DSYCL_ENABLE_EXTENSION_JIT=ON \
            -DSYCL_ENABLE_MAJOR_RELEASE_PREVIEW_LIB=OFF \
            -DSYCL_ENABLE_WERROR=OFF \
            -DSYCL_ENABLE_XPTI_TRACING=ON \
            -DLLVM_EXTERNAL_LIBDEVICE_SOURCE_DIR=$(pwd)/libdevice \
            -DLLVM_EXTERNAL_LLVM_SPIRV_SOURCE_DIR=$(pwd)/llvm-spirv \
            -DLLVM_EXTERNAL_SYCL_JIT_SOURCE_DIR=$(pwd)/sycl-jit \
            -DLLVM_EXTERNAL_SYCL_SOURCE_DIR=$(pwd)/sycl \
            -DLLVM_EXTERNAL_XPTI_SOURCE_DIR=$(pwd)/xpti \
            -DLLVM_EXTERNAL_XPTIFW_SOURCE_DIR=$(pwd)/xptifw \
            -DSYCL_INCLUDE_TESTS=OFF \
            -DXPTI_ENABLE_WERROR=OFF
$ cmake --build _build

/usr/bin/c++ -DUR_ADAPTER_LEVEL_ZERO_V2 -DUR_ENABLE_SANITIZER -DUR_ENABLE_TRACING -DUR_STATIC_LEVEL_ZERO -DUR_VALIDATION_LAYER_SUPPORTED_VERSION=\"0\" -DUR_VERSION=\"0\" -D_DEBUG -D_GLIBCXX_ASSERTIONS -D_GLIBCXX_USE_CXX11_ABI=1 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Dur_adapter_level_zero_v2_EXPORTS -I/home/dvrogozh/git/intel-llvm/_build/unified-runtime/source/adapters/level_zero -I/home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero -I/home/dvrogozh/git/intel-llvm/_build/include -I/home/dvrogozh/git/intel-llvm/llvm/include -I/home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/../.. -I/home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/../../ur -I/home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/LevelZeroLoader-Headers -I/home/dvrogozh/git/intel-llvm/unified-runtime/include -I/home/dvrogozh/git/intel-llvm/unified-runtime/source/common -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/include -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/src -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/src/ravl -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/src/critnib -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/src/provider -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/src/memspaces -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/src/memtargets -I/home/dvrogozh/git/intel-llvm/_build/_deps/unified-memory-framework-src/src/uthash -I/home/dvrogozh/tmp/_install/lib/pkgconfig/../../include/level_zero -I/home/dvrogozh/git/intel-llvm/_build/content-exp-headers/level_zero/include -I/home/dvrogozh/git/intel-llvm/_build/content-exp-headers/level_zero/include/../.. -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wimplicit-fallthrough -Wno-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-dangling-reference -Wno-redundant-move -Wno-pessimizing-move -Wno-array-bounds -Wno-stringop-overread -Wno-noexcept-type -Wdelete-non-virtual-dtor -Wsuggest-override -Wno-comment -Wno-misleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wno-error -O3 -DNDEBUG -std=c++17 -fPIC -UNDEBUG -Wall -Wpedantic -Wempty-body -Wformat -Wformat-security -Wunused-parameter -fstack-protector-strong -fvisibility=hidden -fcf-protection=full -fstack-clash-protection -fdiagnostics-color=always -MD -MT unified-runtime/source/adapters/level_zero/CMakeFiles/ur_adapter_level_zero_v2.dir/v2/graph.cpp.o -MF unified-runtime/source/adapters/level_zero/CMakeFiles/ur_adapter_level_zero_v2.dir/v2/graph.cpp.o.d -o unified-runtime/source/adapters/level_zero/CMakeFiles/ur_adapter_level_zero_v2.dir/v2/graph.cpp.o -c /home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/v2/graph.cpp
In file included from /home/dvrogozh/tmp/_install/lib/pkgconfig/../../include/level_zero/loader/ze_loader.h:16,
                 from /home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/v2/../common.hpp:28,
                 from /home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/v2/common.hpp:16,
                 from /home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/v2/graph.hpp:13,
                 from /home/dvrogozh/git/intel-llvm/unified-runtime/source/adapters/level_zero/v2/graph.cpp:11:
/home/dvrogozh/tmp/_install/lib/pkgconfig/../../include/level_zero/loader/../layers/zel_tracing_register_cb.h:874:5: error: ‘ze_validate_runtime_requirements_output_t’ does not name a type; did you mean ‘_ze_device_validate_runtime_requirements_params_t’?
  874 |     ze_validate_runtime_requirements_output_t** ppOut;
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |     _ze_device_validate_runtime_requirements_params_t
/home/dvrogozh/tmp/_install/lib/pkgconfig/../../include/level_zero/loader/../layers/zel_tracing_register_cb.h:926:5: error: ‘ze_device_compiler_info_t’ does not name a type; did you mean ‘ze_device_properties_t’?
  926 |     ze_device_compiler_info_t* pparamName;
      |     ^~~~~~~~~~~~~~~~~~~~~~~~~
      |     ze_device_properties_t

Please, support this usage scenario. This usage comes from the pytorch CI where dpclang and PTI libraries have different requirements for the minimal L0 version and system level L0 is too old to be used by both. To handle this issue we need to build L0 on pytorch CI side and use it to further build dpclang, PTI and pytorch - that's where we step into issue. On pytorch side see:

• ci/dpclang: profiler related tests fail torch-xpu-ops#5051

CC: @sarnex, @dm-vodopyanov, @mschilling0

[dvrogozh]

Issue happens due to how dpclang handles L0 pkg-config include directories. Specifically here:

llvm/unified-runtime/cmake/FetchLevelZero.cmake

Line 19 in f6de1a6

set(LEVEL_ZERO_INCLUDE_DIR "${level-zero_INCLUDEDIR}/level_zero")

The mistake is that cflags from level-zero.pc are actually ignored. Instead above relies on the includedir variable defined in the level-zero.pc file and manually constructs (actually guessing) includes location by appending /level_zero to the queried includedir. In reality level-zero.pc cflags look like the following:

$ pkg-config --cflags level-zero
-I/home/dvrogozh/tmp/_install/lib/pkgconfig/../../include/level_zero -I/home/dvrogozh/tmp/_install/lib/pkgconfig/../../include

The compilation fails when unified runtime sources inconsistently work with L0 includes (on v7.0.1):

$ fgrep -rsn ze_api.h unified-runtime/
...
unified-runtime/source/adapters/level_zero/queue.hpp:24:#include <ze_api.h>
unified-runtime/source/adapters/level_zero/queue.cpp:25:#include "ze_api.h"
unified-runtime/source/adapters/level_zero/external/driver_experimental/zex_module.h:14:#include <level_zero/ze_api.h>
unified-runtime/source/adapters/level_zero/external/driver_experimental/zex_driver.h:15:#include <level_zero/ze_api.h>
unified-runtime/source/adapters/level_zero/external/driver_experimental/zex_event.h:14:#include <level_zero/ze_api.h>
...

As a result some headers are taken from the system installation of L0 and some from user installation.

The issue in cmake still present on b73d26e (latest sycl branch head as of 8/27/2026), but build passes because there is no inconsistency in how unified runtime includes L0 headers. On v7.0.1 unified runtime includes L0 headers in different manner (see above grep) and build fails.

[dvrogozh]

Workaround possible for v7.0.1 with:

grep -rl '#include <level_zero/ze_api.h>' unified-runtime/ | \
  xargs sed -i 's|#include <level_zero/ze_api.h>|#include <ze_api.h>|g'

[arcusbuilds]

I would like to work on it!

[mschilling0]

Just for reference, on the PTI side - PTI wraps the PC file in a Find module and uses #include <level_zero/ze_api.h>. I think with #include <level_zero/ze_api.h>, on Linux, you don't need to pass any more include flags into the compiler.

This could be helpful with minimal reproducers and not needing to pull L0 headers if the system has already installed them less build system complexity. The caveat being on FetchContent time, one needs to copy the headers into the level_zero directory. (related: oneapi-src/level-zero#260). So it may not be worth it in this case.