Add a script to help test dynamic library loading with Java

CMake/JavaCheck.cmake

@@ -0,0 +1,134 @@
+#                 J A V A 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 dlls can be loaded by the Java
+# System.loadLibrary mechanism. Parameters (all are mandatory):
+#
+# JCEXEC = path to javac compiler
+# JAREXEC = path to jar archive creater
+# JEXEC = path to java executable
+# DLLSUFFIX = platform specific shared library suffix (.so, .dll, etc.)
+# DLL_DIR = directory holding shared library files to check
+
+function(JavaCheck JC_EXEC JAR_EXEC J_EXEC DLL_SUFFIX dlldir)
+
+  if (NOT EXISTS "${dlldir}")
+    message(FATAL_ERROR "Dll directory ${dlldir} not found\n")
+  endif ()
+  if (NOT EXISTS "${JC_EXEC}")
+    message(FATAL_ERROR "Java compiler executable ${JC_EXEC} not found\n")
+  endif ()
+  if (NOT EXISTS "${JAR_EXEC}")
+    message(FATAL_ERROR "Java archive creation executable ${JAR_EXEC} not found\n")
+  endif ()
+  if (NOT EXISTS "${J_EXEC}")
+    message(FATAL_ERROR "Java executable ${J_EXEC} not found\n")
+  endif ()
+
+  file(WRITE ${dlldir}/LoadLib.java "class LoadLib
+{
+        public static void main(String []args)
+        {
+                if (args.length < 1) {
+                        System.out.println(\"No DLL specified\");
+                        System.exit(1);
+                }
+                System.out.println(\"Loading \" + args[0]);
+                System.loadLibrary(args[0]);
+                System.out.println(\"Done\");
+        }
+}
+"
+  )
+
+  # Help make sure Java finds the dynamically linked libraries in question
+  if (WIN32)
+    set(ENV{PATH} "${dlldir};$ENV{PATH}")
+  else (WIN32)
+    set(ENV{LD_LIBRARY_PATH} "${dlldir}")
+  endif (WIN32)
+
+  # Compile the file and create the jar archive
+  execute_process(COMMAND ${JC_EXEC} LoadLib.java
+    RESULT_VARIABLE LSTATUS OUTPUT_VARIABLE LOUT ERROR_VARIABLE LOUT
+    WORKING_DIRECTORY ${dlldir}
+    )
+  if (LSTATUS)
+    file(REMOVE ${dlldir}/LoadLib.java)
+    message(FATAL_ERROR "Failed to compile LoadLib.class: ${LOUT}")
+  endif (LSTATUS)
+  execute_process(COMMAND ${JAR_EXEC} -cf LoadLib.jar LoadLib.class
+    RESULT_VARIABLE LSTATUS OUTPUT_VARIABLE LOUT ERROR_VARIABLE LOUT
+    WORKING_DIRECTORY ${dlldir}
+    )
+  if (LSTATUS)
+    file(REMOVE ${dlldir}/LoadLib.java)
+    file(REMOVE ${dlldir}/LoadLib.class)
+    message(FATAL_ERROR "Failed to create JAR file LoadLib.jar: ${LOUT}")
+  endif (LSTATUS)
+
+  file(GLOB dll_files RELATIVE "${dlldir}" "${dlldir}/*${DLL_SUFFIX}")
+  set(load_fail 0)
+  foreach(dlf ${dll_files})
+    string(REGEX REPLACE "^lib" "" dlf "${dlf}")
+    string(REGEX REPLACE "${DLL_SUFFIX}$" "" dlf "${dlf}")
+    message("Dll LoadLibrary check: ${J_EXEC} -cp LoadLib.jar LoadLib ${dlf}")
+    execute_process(COMMAND ${J_EXEC} -cp LoadLib.jar LoadLib ${dlf}
+      RESULT_VARIABLE LSTATUS OUTPUT_VARIABLE LOUT ERROR_VARIABLE LOUT
+      WORKING_DIRECTORY ${dlldir}
+      )
+    if (LSTATUS)
+      message("LoadLibrary call with dll file ${dlf} did not succeed: ${LOUT}")
+      set(load_fail 1)
+    endif (LSTATUS)
+  endforeach(dlf ${dll_files})
+  file(REMOVE ${dlldir}/LoadLib.java)
+  file(REMOVE ${dlldir}/LoadLib.class)
+  file(REMOVE ${dlldir}/LoadLib.jar)
+  if (load_fail)
+    message(FATAL_ERROR "Dll files present that failed to load with LoadLibrary.")
+  endif (load_fail)
+endfunction(JavaCheck)
+
+if (JCEXEC AND JAREXEC AND JEXEC AND DLLSUFFIX AND DLL_DIR)
+  JavaCheck(${JCEXEC} ${JAREXEC} ${JEXEC} ${DLLSUFFIX} ${DLL_DIR})
+endif ()
+
+# Local Variables:
+# tab-width: 8
+# mode: cmake
+# indent-tabs-mode: t
+# End:
+# ex: shiftwidth=2 tabstop=8