HDFGroup · byrnHDF · May 6, 2025 · May 6, 2025 · May 8, 2025 · May 9, 2025
@@ -791,14 +791,13 @@ endif ()
 
 # Parallel IO usage requires MPI to be Linked and Included
 if (H5_HAVE_PARALLEL)
-  set (LINK_LIBS ${LINK_LIBS} ${MPI_C_LIBRARIES})
+  list (APPEND LINK_PUB_LIBS MPI::MPI_C)
   if (MPI_C_LINK_FLAGS)
     set (CMAKE_EXE_LINKER_FLAGS "${MPI_C_LINK_FLAGS} ${CMAKE_EXE_LINKER_FLAGS}")
   endif ()
 endif ()
 
 # Determine if a threading package is available on this system
-option (HDF5_ENABLE_THREADS "Enable thread support" ON)
 set (THREADS_PREFER_PTHREAD_FLAG ON)
 find_package (Threads)
 if (Threads_FOUND)
@@ -821,12 +820,16 @@ if (Threads_FOUND)
   else ()
     message (FATAL_ERROR " **** thread support requires C11 threads, Win32 threads or Pthreads **** ")
   endif ()
+  set (HDF5_THREADS_ENABLED ON) # Used to init hdf5-config.cmake
+  list (APPEND LINK_LIBS Threads::Threads)
 
   # Check for compiler support for atomic variables
   CHECK_INCLUDE_FILE("stdatomic.h" HAVE_STDATOMIC_H)
   if (HAVE_STDATOMIC_H)
     set (H5_HAVE_STDATOMIC_H 1)
   endif()
+else ()
+  set (HDF5_THREADS_ENABLED OFF) # Used to init hdf5-config.cmake
 endif ()
 
 # Determine whether to build the HDF5 Subfiling VFD
@@ -863,6 +866,8 @@ if (HDF5_ENABLE_SUBFILING_VFD)
   endif()
 endif()
 
+message (VERBOSE "LINK_LIBS=${LINK_LIBS}")
+message (VERBOSE "LINK_PUB_LIBS=${LINK_PUB_LIBS}")
 
 set (HDF5_DEFAULT_API_VERSION "v200" CACHE STRING "Enable v2.0 API (v16, v18, v110, v112, v114, v200)")
 set_property (CACHE HDF5_DEFAULT_API_VERSION PROPERTY STRINGS v16 v18 v110 v112 v114 v200)

@@ -23,6 +23,7 @@ if (NOT DEFINED H5PL_ALLOW_EXTERNAL_SUPPORT)
 endif ()
 
 if (H5PL_ALLOW_EXTERNAL_SUPPORT MATCHES "GIT")
+  set (ENABLE_BITGROOM OFF CACHE BOOL "" FORCE)
   set (ENABLE_JPEG OFF CACHE BOOL "" FORCE)
   set (ENABLE_LZF OFF CACHE BOOL "" FORCE)
 endif ()

@@ -46,7 +46,7 @@ set (${HDF5_PACKAGE_NAME}_INSTALL_MOD_FORTRAN "@HDF5_INSTALL_MOD_FORTRAN@")
 set (${HDF5_PACKAGE_NAME}_BUILD_HL_LIB          @HDF5_BUILD_HL_LIB@)
 set (${HDF5_PACKAGE_NAME}_BUILD_SHARED_LIBS     @H5_ENABLE_SHARED_LIB@)
 set (${HDF5_PACKAGE_NAME}_BUILD_STATIC_LIBS     @H5_ENABLE_STATIC_LIB@)
-set (${HDF5_PACKAGE_NAME}_ENABLE_THREADS        @HDF5_ENABLE_THREADS@)
+set (${HDF5_PACKAGE_NAME}_THREADS_ENABLED       @HDF5_THREADS_ENABLED@)
 set (${HDF5_PACKAGE_NAME}_ENABLE_THREADSAFE     @HDF5_ENABLE_THREADSAFE@)
 set (${HDF5_PACKAGE_NAME}_ENABLE_PARALLEL       @HDF5_ENABLE_PARALLEL@)
 set (${HDF5_PACKAGE_NAME}_DEFAULT_API_VERSION  "@HDF5_DEFAULT_API_VERSION@")
@@ -92,7 +92,7 @@ if (${HDF5_PACKAGE_NAME}_ENABLE_PARALLEL)
   find_package(MPI QUIET REQUIRED)
 endif ()
 
-if (${HDF5_PACKAGE_NAME}_ENABLE_THREADS)
+if (${HDF5_PACKAGE_NAME}_THREADS_ENABLED)
   set(THREADS_PREFER_PTHREAD_FLAG ON)
   find_package(Threads QUIET REQUIRED)
 endif ()

@@ -28,7 +28,7 @@ release_docs/INSTALL_CMake.txt file for more information on the CMake build syst
 | mirror-vfd[Build the socket-based Mirror virtual file driver (VFD). [default=no]] | HDF5_ENABLE_MIRROR_VFD "Build the Mirror Virtual File Driver" [OFF] | if (HDF5_BUILD_UTILS) |
 | ros3-vfd[Build the Read-Only S3 virtual file driver (VFD). [default=no]] | HDF5_ENABLE_ROS3_VFD "Build the ROS3 Virtual File Driver" [OFF] |  |
 | libhdfs[Provide libhdfs library to enable HDFS virtual file driver (VFD) [default=no]] | HDF5_ENABLE_HDFS "Enable HDFS" [OFF] |  |
-| threads[Enable threads capability. A prerequisite for enabling threadsafe API calls.  [default=yes] | HDF5_ENABLE_THREADS "Enable thread support" [ON] |  |
+| threads[Enable threads capability. A prerequisite for enabling threadsafe API calls.  [default=yes] | HDF5_THREADS_ENABLED "Enable thread support" [ON] |  |
 | threadsafe[Enable thread-safe capability. Not compatible with the high-level library, Fortran, or C++ wrappers.  [default=no]] | HDF5_ENABLE_THREADSAFE "Enable Threadsafety" [OFF] |  |
 | file-locking[Sets the default for whether or not to use file locking when opening files. [default=best-effort]] | HDF5_USE_FILE_LOCKING "Use file locking by default (mainly for SWMR)" [ON] | HDF5_IGNORE_DISABLED_FILE_LOCKS "Ignore file locks when disabled on file system" [ON] |
 
@@ -78,5 +78,5 @@ release_docs/INSTALL_CMake.txt file for more information on the CMake build syst
 | ------- |  ------- | ------------ |
 | examplesdir[--with-examplesdir=location], [Specify path for examples [default="DATAROOTDIR/hdf5_examples"]] |  |  |
 | libmfu[--with-libmfu=DIR], [Use the libmfu library [default=no]] |  |  |
-| pthread[--with-pthread=DIR][Specify alternative path to Pthreads library] | Handled by HDF5_ENABLE_THREADS |  |
+| pthread[--with-pthread=DIR][Specify alternative path to Pthreads library] | Handled by HDF5_THREADS_ENABLED |  |
 
@@ -47,6 +47,14 @@ New Features
 
     Configuration:
     -------------
+    - Removed HDF5_ENABLE_THREADS option
+
+      The HDF5_ENABLE_THREADS option has been removed, as it no longer functions
+      as a proper build option. The library will always check for thread support
+      and set the internal status variable, HDF5_THREADS_ENABLED.
+      The HDF5_ENABLE_THREADSAFE option is still available to build with
+      thread-safe API calls.
+
     - Added CMake configuration options to override compilers in h5cc:
 
           HDF5_H5CC_C_COMPILER       for the C compiler

@@ -1110,13 +1110,8 @@ if (BUILD_STATIC_LIBS)
   TARGET_C_PROPERTIES (${HDF5_LIB_TARGET} STATIC)
   target_link_libraries (${HDF5_LIB_TARGET}
       PRIVATE ${LINK_LIBS} ${LINK_COMP_LIBS}
-      PUBLIC "$<$<PLATFORM_ID:Windows>:${LINK_PUB_LIBS}>" "$<$<NOT:$<PLATFORM_ID:Windows>>:${CMAKE_DL_LIBS}>" "$<$<BOOL:${HDF5_ENABLE_PARALLEL}>:MPI::MPI_C>"
+      PUBLIC ${LINK_PUB_LIBS}
   )
-  if (NOT WIN32)
-    target_link_libraries (${HDF5_LIB_TARGET}
-      PRIVATE "$<$<OR:$<BOOL:${HDF5_ENABLE_THREADS}>,$<BOOL:${HDF5_ENABLE_SUBFILING_VFD}>>:Threads::Threads>"
-    )
-  endif ()
   set_global_variable (HDF5_LIBRARIES_TO_EXPORT ${HDF5_LIB_TARGET})
   H5_SET_LIB_OPTIONS (${HDF5_LIB_TARGET} ${HDF5_LIB_NAME} STATIC 0)
   set_target_properties (${HDF5_LIB_TARGET} PROPERTIES FOLDER libraries)
@@ -1137,16 +1132,14 @@ if (BUILD_SHARED_LIBS)
           "H5_BUILT_AS_DYNAMIC_LIB"
           ${HDF_EXTRA_C_FLAGS}
       PRIVATE
-          "$<$<BOOL:${HDF5_ENABLE_THREADS}>:H5_HAVE_THREADS>"
-          "$<$<BOOL:${HDF5_ENABLE_THREADSAFE}>:H5_HAVE_THREADSAFE>"
           "$<$<BOOL:${HDF5_ENABLE_TRACE}>:H5_DEBUG_API>"  # Enable tracing of the API
           "$<$<BOOL:${HDF5_ENABLE_DEBUG_APIS}>:${HDF5_DEBUG_APIS}>"
           "$<$<CONFIG:Developer>:${HDF5_DEVELOPER_DEFS}>"
   )
   TARGET_C_PROPERTIES (${HDF5_LIBSH_TARGET} SHARED)
   target_link_libraries (${HDF5_LIBSH_TARGET}
       PRIVATE ${LINK_LIBS} ${LINK_COMP_LIBS}
-      PUBLIC "$<$<PLATFORM_ID:Windows>:${LINK_PUB_LIBS}>" "$<$<NOT:$<PLATFORM_ID:Windows>>:${CMAKE_DL_LIBS}>" "$<$<BOOL:${HDF5_ENABLE_PARALLEL}>:MPI::MPI_C>" "$<$<OR:$<BOOL:${HDF5_ENABLE_THREADS}>,$<BOOL:${HDF5_ENABLE_SUBFILING_VFD}>>:Threads::Threads>"
+      PUBLIC ${LINK_PUB_LIBS}
   )
   set_global_variable (HDF5_LIBRARIES_TO_EXPORT "${HDF5_LIBRARIES_TO_EXPORT};${HDF5_LIBSH_TARGET}")
   H5_SET_LIB_OPTIONS (${HDF5_LIBSH_TARGET} ${HDF5_LIB_NAME} SHARED "LIB")

@@ -73,7 +73,7 @@ Features:
 Dimension scales w/ new references: @DIMENSION_SCALES_WITH_NEW_REF@
                   Build HDF5 Tests: @BUILD_TESTING@
                   Build HDF5 Tools: @HDF5_BUILD_TOOLS@
-                           Threads: @HDF5_ENABLE_THREADS@
+                           Threads: @HDF5_THREADS_ENABLED@
                       Threadsafety: @HDF5_ENABLE_THREADSAFE@
                        Concurrency: @HDF5_ENABLE_CONCURRENCY@
                Default API mapping: @HDF5_DEFAULT_API_VERSION@