First cut at logic to check LoadLibrary behavior with output dlls.

CMake/DllTypeCheck.cmake

@@ -48,7 +48,7 @@ function(DllTypeCheck btype dlldir)
   file(GLOB dll_files RELATIVE "${dlldir}" "${dlldir}/*.dll")
   set(non_match 0)
   foreach(dlf ${dll_files})
-    message("Checking ${dlf}")
+    message("Dll Type check: ${dlf}")
     # dumpbin doesn't like CMake style paths
     file(TO_NATIVE_PATH "${dlf}" TBFN)
     # https://stackoverflow.com/a/28304716/2037687

CMake/LoadLibraryCheck.cmake

@@ -0,0 +1,70 @@
+#           L O A D L I B R A R Y C H E C K . C M A K E
+# BRL-CAD
+#
+# Copyright (c) 2024 United States Government as represented by
+# the U.S. Army Research Laboratory.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following
+# disclaimer in the documentation and/or other materials provided
+# with the distribution.
+#
+# 3. The name of the author may not be used to endorse or promote
+# products derived from this software without specific prior written
+# permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+# GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+###
+# Utility function to check that a dll can be loaded by the LoadLibrary
+# function on Windows.
+
+function(LoadLibraryCheck LLTEST_EXEC dlldir)
+  if (NOT EXISTS "${dlldir}")
+    return()
+  endif (NOT EXISTS "${dlldir}")
+  if (NOT EXISTS "${LLTEST_EXEC}")
+    return()
+  endif (NOT EXISTS "${LLTEST_EXEC}")
+  file(GLOB dll_files RELATIVE "${dlldir}" "${dlldir}/*.dll")
+  set(load_fail 0)
+  foreach(dlf ${dll_files})
+    message("Dll LoadLibrary check: ${dlf}")
+    execute_process(COMMAND ${LLTEST_EXEC} ${dlf} RESULT_VARIABLE LSTATUS OUTPUT_VARIABLE LOUT)
+    if (LSTATUS)
+      message("LoadLibrary call with dll file ${dllfile} did not succeed.")
+      set(load_fail 1)
+    endif (LSTATUS)
+  endforeach(dlf ${dll_files})
+  if (load_fail)
+    message(FATAL_ERROR "Dll files present that failed to load with LoadLibrary.")
+  endif (load_fail)
+endfunction(LoadLibraryCheck)
+
+if (CMAKE_BUILD_TYPE AND LEXEC AND DLL_DIR)
+  LoadLibraryCheck(${CMAKE_BUILD_TYPE} ${LEXEC} ${DLL_DIR})
+endif (CMAKE_BUILD_TYPE AND LEXEC AND DLL_DIR)
+
+# Local Variables:
+# tab-width: 8
+# mode: cmake
+# indent-tabs-mode: t
+# End:
+# ex: shiftwidth=2 tabstop=8

CMake/LoadLibraryTest.cpp

@@ -0,0 +1,43 @@
+/*             L O A D L I B R A R Y T E S T . C P P
+ *
+ * Published in 2024 by the United States Government.
+ * This work is in the public domain.
+ *
+ */
+/** @file LoadLibraryTest.cpp
+ *
+ * File to test if a Dll file can be successfully loaded
+ * by the Windows LoadLibrary call.
+ */
+
+#include <windows.h>
+#include <stdio.h>
+
+int main(int argc, const char **argv)
+{
+    if (argc < 2) {
+	printf("lltest <dllfile>\n");
+	return -1;
+    }
+    HINSTANCE linst = LoadLibrary(TEXT(argv[1]));
+    if (linst == NULL) {
+	printf("LoadLibrary of %s failed\n", argv[1]);
+	return 1;
+    }
+    Bool flr = FreeLibrary(linst);
+    if (!flr) {
+	printf("FreeLibrary failed for %s\n", argv[1]);
+	return 1;
+    }
+    printf("Success\n");
+    return 0;
+}
+
+// Local Variables:
+// tab-width: 8
+// mode: C++
+// c-basic-offset: 4
+// indent-tabs-mode: t
+// c-file-style: "stroustrup"
+// End:
+// ex: shiftwidth=4 tabstop=8

CMakeLists.txt

@@ -491,9 +491,20 @@ endif (EXISTS "${CMAKE_BUNDLE_INSTALL_PREFIX}" AND STALE_INSTALL_WARN)
 # On Windows, if we get dlls built for the wrong configuration it can cause
 # problems.  Define a utility target to check
 ###############################################################################
-add_custom_target(dllcheck
+add_custom_target(dll_typecheck
   COMMAND ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=\"$<CONFIG>\" -DDLL_DIR=\"${CMAKE_INSTALL_PREFIX}/bext_output/install/bin\" -P ${CMAKE_SOURCE_DIR}/CMake/DllTypeCheck.cmake)
 
+###############################################################################
+# Check that Windows LoadLibrary call can succeed with our dll outputs
+###############################################################################
+if (WIN32)
+  add_executable(lltest ${CMAKE_CURRENT_SOURCE_DIR}/LoadLibraryTest.cpp)
+  add_custom_target(dll_loadcheck
+    COMMAND ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=\"$<CONFIG>\" -DLEXEC=\"$<TARGET_FILE>:lltest\" -DDLL_DIR=\"${CMAKE_INSTALL_PREFIX}/bext_output/install/bin\" -P ${CMAKE_SOURCE_DIR}/CMake/LoadLibraryCheck.cmake
+    DEPENDS lltest
+    )
+endif (WIN32)
+
 ###############################################################################
 # Report where we will be putting our output
 ###############################################################################