RELEASE-NOTES.md

BLT Software Release Notes

Notes describing significant changes in each BLT release are documented in this file.

The format of this file is based on Keep a Changelog.

The project release numbers follow Semantic Versioning.

Unreleased - Release date yyyy-mm-dd

Changed

• Removed default use of /bigobj flag for Visual Studio builds. Projects should add this flag explicitly if needed for windows builds.
• Removed -Winline from being added to GoogleTest for Clang/Intel as it is a noop and caused a warning on Intel.
• Toggle GoogleTest adding -Wno-implicit-float-size-conversion or -Wno-sycl-implicit-float-size-conversion based on Intel version.
• Update CUDA runtime smoketest to be compatible with CUDA 13

Fixed

• In non-mpi configurations, blt_add_test will now throw a FATAL_ERROR if the user provides NUM_MPI_RANKS and the requested number of ranks is greater than 1. Previously, if MPI_EXECUTABLE was not defined blt_add_test would prepend the test command with the value of NUM_MPI_RANKS, and the test would fail to run.
• GoogleTest: Quiet warning on clang@21 about implicit cast (https://github.com/google/googletest/commit/fa8438ae6b70c57010177de47a9f13d7041a6328)

Version 0.7.1 - Release date 2025-09-04

Changed

• Updated GoogleTest to 1.16.0
• Improved CMake information output for CUDA builds

Version 0.7.0 - Release date 2025-03-11

Added

• Added WORKING_DIRECTORY option to blt_add_test and blt_add_benchmark.
• Added BLT_CXX_FILE_EXTS variable (split out of BLT_C_FILE_EXTS) for use in modified blt_split_source_list_by_language macro.

Changed

• Modified blt_convert_to_system_includes to handle multiple targets and recursively update includes for dependencies.
• Modified blt_split_source_list_by_language to accept a CXX_LIST argument for splitting out C and CXX sources. If not specified, the C_LIST will contain both C and C++ sources.
• HIP support now uses enable_language(HIP), and specifying a HIP compiler must use the variable CMAKE_HIP_COMPILER.
• Updated GoogleBenchmark to 1.9.1

Fixed

• Removed GoogleTest, GoogleMock, and GoogleBenchmarks calling CMake's GNUInstallDirs which was causing non-deterministic install variables depending on your combination of static/shared libraries and if any of the previously mentioned TPLs were enabled.
• Enable C language support and emit a warning when GoogleTest or GoogleMock are enabled but not the C language.
• Guard HIP C smoketest against projects that don't enable C as a language in their projects.
• Changes benchmark custom target run_benchmarks to exclusively run benchmarks (not other general tests).
• Fix HIP smoketests to fail on HIP errors.
• Add -Wno-tautological-compare to GoogleTest/Mock/Benchmark for IntelLLVM compilers to silence warning.

Version 0.6.2 - Release date 2024-03-15

Added

• Added output for CMake's implicitly added link libraries and directories.

Changed

• OpenMP target now uses a generator expression for Fortran flags instead of replacing flags in Fortran targets created with BLT macros.
• Remove setting CMP0076 to OLD which left relative paths in target_sources() instead of altering them to absolute paths.
• Header-only libraries headers now show up under their own target in IDE project views instead of under downstream targets. This only works in CMake >= 3.19, otherwise they will not show up at all.
• Raised version for base CMake version supported by BLT to 3.15 to support ALIAS targets across BLT.

Version 0.6.1 - Release date 2024-01-29

Fixed

• Turned off GoogleTest finding Python

Version 0.6.0 - Release date 2024-01-18

Added

• Added support for C++23. Note: XL and PGI do not support C++23.
• Adds a clang_tidy_style CMake target to allow clang-tidy to fix errors in-place. This requires a CLANGAPPLYREPLACEMENTS_EXECUTABLE CMake variable to point to the clang-apply-replacements executable in addition to the CLANGTIDY_EXECUTABLE. Also adds a corresponding ENABLE_CLANGAPPLYREPLACEMENTS CMake option. Note that the clang_tidy_style target is not added to the style target and must be run separately.
• Added the blt_install_tpl_setups macro, which installs files to setup and create targets for the third-party libraries OpenMP, MPI, CUDA, and HIP. This macro is meant to replace blt_export_tpl_targets as the preferred way to setup third-party libraries with BLT.
• Added blt:: namespaced aliases for BLT targets, cuda, cuda_runtime, mpi, and openmp. These targets still exist but but will be deprecated in a future release. It is recommended that you move to the new alias names, blt::cuda, blt::cuda_runtime, blt::mpi, and blt::openmp

Changed

• SetupHIP now searches for user-defined or environment variables before CMake paths to find the ROCM_PATH.

Fixed

• Fixed infinite loop in blt_find_target_dependencies
• blt_check_code_compiles now works with alias targets

Version 0.5.3 - Release date 2023-06-05

Changed

• Updated Googletest to main from 04/13/2023. Commit: 12a5852e451baabc79c63a86c634912c563d57bc. Note: this version of Googletest requires C++14, and PGI is not supported. If you are using PGI, set ENABLE_GTEST OFF.
• Updated GoogleBenchmark to 1.8
• The clang_tidy_check target is no longer registered with the main check target since its changes are not always safe/valid.

Added

• Added blt_print_variables macro to print variables in current scope, with regex filtering on variable names and values
• Added DEPENDS_ON optional parameter to blt_check_code_compiles macro to allow for checking if a feature is available in a third-party imported target.
• Added CONFIGURATIONS and OMP_NUM_THREADS options to blt_add_benchmark

Fixed

• Guard HIP compiler flag --rocm-path=/path/to/rocm against Crayftn compiler earlier than 15.0.0.
• Fix doubling of INTERFACE_INCLUDE_DIRECTORIES in blt_patch_target(... TREAT_INCLUDES_AS_SYSTEM true).

Removed

• Removed tracking all sources in a project via ${PROJECT_NAME}_ALL_SOURCES.

Version 0.5.2 - Release date 2022-10-05

Added

• Added blt_convert_to_system_includes macro to convert existing interface includes to system interface includes.
• blt_check_code_compiles which compiles a C++ code snippet and returns the result.
• Added variable BLT_CMAKE_IMPLICIT_LINK_LIBRARIES_EXCLUDE for filtering link libraries implicitly added by CMake. See the following example host-config: host-configs/llnl/blueos_3_ppc64le_ib_p9/clang@upstream_nvcc_xlf.cmake

Changed

• Added three extra options to blt_print_target_properties macro to print properties of target's children as well as limit the properties printed with regular expressions:
  • CHILDREN (true/ false) whether or not you want to print the target's children's properties as well (recursively)
  • PROPERTY_NAME_REGEX (regular expression string) reduce which properties to print by name
  • PROPERTY_VALUE_REGEX (regular expression string) reduce which properties to print by value

Version 0.5.1 - Release date 2022-04-22

Added

• Added support for C++20. Note: XL does not support C++20. While PGI has C++20 support, it is currently disabled (A BLT fatal error will occur).
• BLT_CXX_STD now sets CMAKE_HIP_STANDARD, in CMake 3.21+, similar to CMAKE_CUDA_STANDARD.

Fixed

• Removed hard-coded -std=c++11 from various places related to CUDA flags. This now honors CMAKE_CUDA_STANDARD if set otherwise falls back on BLT_CXX_STD or CMAKE_CXX_STANDARD.
• Removed extra HIP offload flags that were being added as generator expressions as opposed to simple flags.
• Skip check for valid ELEMENTS parameter in blt_list_append macro when not appending

Removed

• Removed support for deprecated HCC.

Version 0.5.0 - Release date 2022-03-07

Added

• Added support for IntelLLVM compiler family to blt_append_custom_compiler_flag
• Added support for hip targets configured with cmake 3.21 native hip support
• Added blt_export_tpl_targets macro to add BLT-provided third-party library targets to an export set.

Changed

• BLT_C_FILE_EXTS updated to include .cuh
• Fold BLT_CLANG_HIP_ARCH into the CMAKE_HIP_ARCHITECTURES variable
• When using ENABLE_ALL_WARNINGS, append the flag to the beginning of CMAKE_{C,CXX}_FLAGS instead of the end
• HIP support now uses the hip-config.cmake file provided by ROCM. This modification requires a change to the BLT-provided HIP target names, and they are now available under the blt prefix: blt::hip and blt::hip_runtime.

Fixed

• Source code filename extension filtering now uses regular expressions to allow for more user customization and to improve handling of file names with multiple periods, e.g. 1d.cube.order2.c is considered a .c file.

Version 0.4.1 - Release date 2021-07-20

Added

• Added compilation of HIP with clang using ENABLE_CLANG_HIP and BLT_CLANG_HIP_ARCH

Changed

• XL: Use compiler flag -std=c++14 instead of -std=c++1y when BLT_CXX_STD is set to c++14

Fixed

• Simplified the clang-format version regex that was causing hangs on some version strings.

Version 0.4.0 - Release date 2021-04-09

Added

• Added variable BLT_CMAKE_IMPLICIT_LINK_DIRECTORIES_EXCLUDE for filtering link directories implicitly added by CMake. See the following example host-config: host-configs/llnl/blueos_3_ppc64le_ib_p9/clang@upstream_nvcc_c++17.cmake
• Added support for clang-tidy static analysis check
• Added ability to change the output name of an executable via the OUTPUT_NAME parameter of blt_add_executable
• Added user option for enforcing specific versions of autoformatters - the new options are BLT_REQUIRED_ASTYLE_VERSION, BLT_REQUIRED_CLANGFORMAT_VERSION, and BLT_REQUIRED_UNCRUSTIFY_VERSION
• Added HEADERS to blt_add_executable. This is important for build system dependency tracking and IDE folder support.
• Added support for formatting Python code using YAPF.
• Added new blt_import_library macro that creates a real CMake target for imported libraries, intended to be used instead of blt_register_library whenever possible
• Added new blt_patch_target macro to simplify modifying properties of an existing CMake target. This macro accounts for known differences in compilers, target types, and CMake releases.
• Added support for formatting CMake code using cmake-format.
• Added an EXPORTABLE option to blt_import_library that allows imported libraries to be added to an export set and installed.
• Added FRUIT's MPI parallel unit test reporting to BLT's internal copy of FRUIT
• CUDA device links for object libraries can be enabled with the existing CUDA_RESOLVE_DEVICE_SYMBOLS target property.

Changed

• MPI Support when using CMake 3.13 and newer: MPI linker flags are now passed as single string prefixed by SHELL: to prevent de-duplication of flags passed to target_link_options.
• For HIP-dependent builds, only add HCC include directory if it exists.
• HIP CMake utilities updated to AMD's latest version
• Updated add_code_coverage_target to blt_add_code_coverage_target, which now supports user-specified source directories
• Code coverage targets leave LCOV-generated files intact for later use; these files will still be removed by make clean

Fixed

• ClangFormat checks now support multiple Python executable names
• Prefixed blt_register_library() internal variables with _ to avoid collision with input parameters.
• Turn off system includes for registered libraries when using the PGI compiler
• Removed unneeded SYSTEM includes added by googletest that was causing problems in PGI builds (BLT was adding them already to the register library calls)
• Removed variable BLT_CMAKE_CUDA_IMPLICIT_LINK_DIRECTORIES_EXCLUDE, functionality now provided for all languages using BLT_CMAKE_IMPLICIT_LINK_DIRECTORIES_EXCLUDE variable
• ClangQuery was being auto-enabled in cases where no checker directories where defined. This caused a crash. blt_add_clang_query_target learned parameter CHECKER_DIRECTORIES and blt_add_code_checks learned parameter CLANGQUERY_CHECKER_DIRECTORIES. Both still respect BLT_CLANGQUERY_CHECKER_DIRECTORIES.
• It is now a fatal error to supply CLANGFORMAT_CFG_FILE plus ASTYLE_CFG_FILE or UNCRUSTIFY_CFG_FILE arguments to blt_add_code_checks; previously, these combinations were implied to be errors in BLT documentation, but BLT would not return an error in those cases.
• blt_patch_target no longer attempts to set system include directories when a target has no include directories
• Header-only libraries now can have dependencies via DEPENDS_ON in blt_add_library
• Added a workaround for include directories of imported targets on PGI. CMake was erroneously marking them as SYSTEM but this is not supported by PGI.
• Check added to make sure that if HIP is enabled with fortran, the LINKER LANGUAGE is not changed back to Fortran.
• Executables that link to libraries that depend on hip/hip_runtime/cuda/cuda_runtime will automatically be linked with the HIP or CUDA (NVCC) linker
• Patched an issue with the FindHIP macros that added the inclusive scan of specified DEFINEs to compile commands
• Re-added previous OpenMP flag patching logic to maintain compatibility with BLT-registered libraries

Version 0.3.6 - Release date 2020-07-27

Changed

• CUDA_TOOLKIT_ROOT_DIR is now optional. If it is not specified, FindCUDA.cmake will attempt to set it.

Version 0.3.5 - Release date 2020-07-20

Added

• Added blt_assert_exists() utility macro.
• Additional link flags for CUDA may now be specified by setting CMAKE_CUDA_LINK_FLAGS when configuring CMake either in a host-config or at the command-line.
• Added support for ClangFormat.

Changed

• CUDA_TOOLKIT_ROOT_DIR must now be set in order to use CUDA. If it is not specified, BLT will produce an error message.

Fixed

• blt_add_test is no longer trying to extract target properties from non-targets.
• Improved support for HIP 3.5.
• Improved support for CMake 3.13.0+.
• Remove some known spaces that show up in MPI link flags.
• Remove GTest and GBenchmark adding '-Werror' that got inherited.

Version 0.3.0 - Release date 2020-01-08

Added

• Sets CMake policy CMP0074 to NEW, when available.
• Added simpler Clang+XLF+Cuda host-config for LLNL's blueos
• API Docs that are public!
• Added the ability to override blt's custom target names, e.g. for code checks, formatting and generating documentation. The new variables are: BLT_CODE_CHECK_TARGET_NAME, BLT_CODE_STYLE_TARGET_NAME, BLT_DOCS_TARGET_NAME and BLT_RUN_BENCHMARKS_TARGET_NAME.
• Clean up linking flags when CUDA_LINK_WITH_NVCC is ON. Added logic to automatically convert '-Wl,-rpath' linking flag to '-Xlinker -rpath -Xlinker' and removes -pthread from from MPI linking flags returned from FindMPI because it doesn't work (see https://gitlab.kitware.com/cmake/cmake/issues/18008).
• In CMake 3.13+, "SHELL:" was added to blt_add_target_link_flags. This stops CMake from de-duplicating needed linker flags.
• Added optional SCOPE to all target property macros, blt_add_target_link_flags, etc. It defaults to PUBLIC.
• Added support for Cray compilers in blt_append_custom_compiler_flag.
• Added ability to add flags to the cppcheck command line through blt_add_code_checks()
• Added ability for blt_add_test() to set required number of OpenMP threads via new option NUM_OMP_THREADS.
• Added ClangFormat as an option for code styling. This has some caveats that are noted here: https://llnl-blt.readthedocs.io/en/develop/api/code_check.html

Changed

• Restructured the host-config directory by site and platform.
• Updated gbenchmark to 1.5.0, note that this requires C++11 to build.
• Updated gtest and gmock to Master as of 2020-01-07, note that this requires C++11 to build.

Fixed

• Fixed some warnings in CMake 3.14+
• Duplication of MPI link flags in CMake 3.14+ when Fortran was enabled.

Removed

• Removed unused HEADERS_OUTPUT_SUBDIR argument from blt_add_library().

Version 0.2.5 - Release date 2019-06-13

Added

• Added support for C++17. Note: Neither XL nor CMake's CUDA_STANDARD supports C++17 (A BLT fatal error will occur).
• Added ability to override all MPI variables: BLT_MPI_COMPILE_FLAGS, BLT_MPI_INCLUDES, BLT_MPI_LIBRARIES, and BLT_MPI_LINK_FLAGS
• blt_list_remove_duplicates(): macro for removing duplicates from a list that doesn't error on empty lists.

Changed

• Handle CMake 3.10+ changing all the FindMPI output variables.
• BLT_CXX_STD is no longer defined to "c++11" by default. If undefined, BLT will not try and add any C++ standard flags.
• Handle FindMPI variable MPIEXEC changed to MPIEXEC_EXECUTABLE in CMake 3.10+. This now works regardless of which the user defines or what CMake returns.
• Handle CMake target property LINK_FLAGS changed to LINK_OPTIONS in CMake 3.13+. blt_add_target_link_flags() handles this under the covers and converts the users strings to a list (3.13+) or list to a string (<3.13). New property supports generator expressions so thats a plus.
• Improved how all BLT MPI information is being merged together and reported to users.
• Increased number of ranks in blt_mpi_smoke test to catch regression.
• blt_split_source_list_by_language now supports non-BLT object libraries and errors out when any other generator expression is given in source list. This is to avoid very bad side effects of not being able to set source properties on anything inside the generator expression. This is because BLT cannot evaluate them.

Fixed

• Error out with better message when empty file extensions is hit in blt_split_source_list_by_language.

Version 0.2.0 - Release date 2019-02-15

Added

• Release notes...
• Explicitly check for CMake 3.8+ for required CMake features (Not fatal error)
• Object library support through blt_add_library(... OBJECT TRUE ...)
• Now reporting BLT version through CMake cache variable BLT_VERSION
• Output CMake version and executable used during CMake step
• Clang-query support now added (Thanks David Poliakoff)

Removed

Deprecated

Changed

• Object libraries no longer call target_link_libraries() but will pass inherited information because why would anyone ever want to install/export a bunch of object files.
• Remove duplicates of select target properties at the end of blt_add_library and blt_add_executable. (include directories and compile defines)

Fixed

• Incorrect use of cuda vs cuda_runtime targets
• Improved tutorial documentation
• Incorrect use of Fortran flags with CUDA (Thanks Robert Blake)
• Handle correctly CMake version differences with CUDA host compiler variables (Thanks Randy Settgast)
• Handle uncrustify (version 0.68) command line option changes (--no-backup)

Known Bugs