From 447765609befbf16fcff471b2fda913c3e31432b Mon Sep 17 00:00:00 2001
From: Dana Robinson <43805+derobins@users.noreply.github.com>
Date: Tue, 3 Oct 2023 16:37:44 -0700
Subject: 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
---
 CMakeLists.txt           |  5 +++--
 release_docs/RELEASE.txt | 11 +++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index da6a4d1..aa91dbe 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -872,8 +872,9 @@ option (HDF5_ENABLE_THREADSAFE "Enable thread-safety" OFF)
 if (HDF5_ENABLE_THREADSAFE)
   # check for unsupported options
   if (WIN32)
-    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_BUILD_FORTRAN)
     if (NOT ALLOW_UNSUPPORTED)
diff --git a/release_docs/RELEASE.txt b/release_docs/RELEASE.txt
index 0e1dbe4..4214631 100644
--- a/release_docs/RELEASE.txt
+++ b/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
+
     - Autotools builds now build the szip filter by default when an appropriate
       library is found
 
-- 
cgit v0.12