Disable static + thread-safe on Windows w/ CMake (#3622) (#3631)

* Disable static + thread-safe on Windows w/ CMake (#3622)

The thread-safety feature on Windows requires a hook in DllMain() and thus
is only available when HDF5 is built as a shared library.

This was previously a warning, but has now been elevated to a fatal error
that cannot be overridden with ALLOW_UNSUPPORTED.

Fixes GitHub #3613

.github/workflows/main.yml

@@ -455,6 +455,7 @@ jobs:
         if: (matrix.generator != 'autogen') && ! (matrix.thread_safety.enabled)
 
 
+      # NOTE: Windows does not support static + thread-safe
       - name: CMake Configure (Thread-Safe)
         run: |
           mkdir "${{ runner.workspace }}/build"
@@ -464,6 +465,7 @@ jobs:
             -DCMAKE_BUILD_TYPE=${{ matrix.build_mode.cmake }} \
             -DCMAKE_TOOLCHAIN_FILE=${{ matrix.toolchain }} \
             -DBUILD_SHARED_LIBS=ON \
+            -DBUILD_STATIC_LIBS=OFF \
             -DHDF5_ENABLE_ALL_WARNINGS=ON \
             -DHDF5_ENABLE_THREADSAFE:BOOL=ON \
             -DHDF5_ENABLE_PARALLEL:BOOL=${{ matrix.parallel }} \

CMakeLists.txt

@@ -820,9 +820,8 @@ option (HDF5_ENABLE_THREADSAFE "Enable thread-safety" OFF)
 if (HDF5_ENABLE_THREADSAFE)
   # check for unsupported options
   if (WIN32)
-    if (CMAKE_VERSION VERSION_GREATER_EQUAL "3.15.0")
-      message (VERBOSE " **** thread-safety option not supported with static library **** ")
-      message (VERBOSE " **** thread-safety option will not be used building static library **** ")
+    if (BUILD_STATIC_LIBS)
+        message (FATAL_ERROR " **** thread-safety option not supported with static library **** ")
     endif ()
   endif ()
   if (HDF5_ENABLE_PARALLEL)

release_docs/RELEASE.txt

@@ -47,6 +47,17 @@ New Features
 
     Configuration:
     -------------
+    - Thread-safety + static library disabled on Windows w/ CMake
+
+      The thread-safety feature requires hooks in DllMain(), which is only
+      present in the shared library.
+
+      We previously just warned about this, but now any CMake configuration
+      that tries to build thread-safety and the static library will fail.
+      This cannot be overridden with ALLOW_UNSUPPORTED.
+
+      Fixes GitHub issue #3613
+
     - Bumped the minimum required version of Autoconf to 2.71.
 
       This fixes a problem with the Intel oneAPI Fortran compiler's -loopopt