Add option to build CMake against a system librhash

Create a CMAKE_USE_SYSTEM_LIBRHASH option.

CMakeLists.txt

@@ -104,7 +104,7 @@ macro(CMAKE_HANDLE_SYSTEM_LIBRARIES)
 
   # Allow the user to enable/disable all system utility library options by
   # defining CMAKE_USE_SYSTEM_LIBRARIES or CMAKE_USE_SYSTEM_LIBRARY_${util}.
-  set(UTILITIES BZIP2 CURL EXPAT FORM JSONCPP LIBARCHIVE LIBLZMA LIBUV ZLIB)
+  set(UTILITIES BZIP2 CURL EXPAT FORM JSONCPP LIBARCHIVE LIBLZMA LIBRHASH LIBUV ZLIB)
   foreach(util ${UTILITIES})
     if(NOT DEFINED CMAKE_USE_SYSTEM_LIBRARY_${util}
         AND DEFINED CMAKE_USE_SYSTEM_LIBRARIES)
@@ -144,6 +144,7 @@ macro(CMAKE_HANDLE_SYSTEM_LIBRARIES)
     "${CMAKE_USE_SYSTEM_LIBRARY_LIBLZMA}" "NOT CMAKE_USE_SYSTEM_LIBARCHIVE" ON)
   option(CMAKE_USE_SYSTEM_FORM "Use system-installed libform" "${CMAKE_USE_SYSTEM_LIBRARY_FORM}")
   option(CMAKE_USE_SYSTEM_JSONCPP "Use system-installed jsoncpp" "${CMAKE_USE_SYSTEM_LIBRARY_JSONCPP}")
+  option(CMAKE_USE_SYSTEM_LIBRHASH "Use system-installed librhash" "${CMAKE_USE_SYSTEM_LIBRARY_LIBRHASH}")
   option(CMAKE_USE_SYSTEM_LIBUV "Use system-installed libuv" "${CMAKE_USE_SYSTEM_LIBRARY_LIBUV}")
 
   # For now use system KWIML only if explicitly requested rather
@@ -298,9 +299,22 @@ macro (CMAKE_BUILD_UTILITIES)
     add_subdirectory(Utilities/KWIML)
   endif()
 
-  set(CMAKE_LIBRHASH_LIBRARIES cmlibrhash)
-  add_subdirectory(Utilities/cmlibrhash)
-  CMAKE_SET_TARGET_FOLDER(cmlibrhash "Utilities/3rdParty")
+  if(CMAKE_USE_SYSTEM_LIBRHASH)
+    if(NOT CMAKE_VERSION VERSION_LESS 3.0)
+      find_package(LibRHash)
+    else()
+      message(FATAL_ERROR "CMAKE_USE_SYSTEM_LIBRHASH requires CMake >= 3.0")
+    endif()
+    if(NOT LibRHash_FOUND)
+      message(FATAL_ERROR
+        "CMAKE_USE_SYSTEM_LIBRHASH is ON but LibRHash is not found!")
+    endif()
+    set(CMAKE_LIBRHASH_LIBRARIES LibRHash::LibRHash)
+  else()
+    set(CMAKE_LIBRHASH_LIBRARIES cmlibrhash)
+    add_subdirectory(Utilities/cmlibrhash)
+    CMAKE_SET_TARGET_FOLDER(cmlibrhash "Utilities/3rdParty")
+  endif()
 
   #---------------------------------------------------------------------
   # Build zlib library for Curl, CMake, and CTest.

Utilities/cmThirdParty.h.in

@@ -13,6 +13,7 @@
 #cmakedefine CMAKE_USE_SYSTEM_LIBLZMA
 #cmakedefine CMAKE_USE_SYSTEM_FORM
 #cmakedefine CMAKE_USE_SYSTEM_JSONCPP
+#cmakedefine CMAKE_USE_SYSTEM_LIBRHASH
 #cmakedefine CMAKE_USE_SYSTEM_LIBUV
 #cmakedefine CTEST_USE_XMLRPC
 

Utilities/cm_rhash.h

@@ -3,6 +3,12 @@
 #ifndef cm_rhash_h
 #define cm_rhash_h
 
+/* Use the LibRHash library configured for CMake.  */
+#include "cmThirdParty.h"
+#ifdef CMAKE_USE_SYSTEM_LIBRHASH
+#include <rhash.h>
+#else
 #include <cmlibrhash/librhash/rhash.h>
+#endif
 
 #endif

bootstrap

@@ -493,6 +493,8 @@ Configuration:
   --no-system-liblzma     use cmake-provided liblzma library (default)
   --system-libarchive     use system-installed libarchive library
   --no-system-libarchive  use cmake-provided libarchive library (default)
+  --system-librhash       use system-installed librhash library
+  --no-system-librhash    use cmake-provided librhash library (default)
 
   --qt-gui                build the Qt-based GUI (requires Qt >= 4.2)
   --no-qt-gui             do not build the Qt-based GUI (default)
@@ -726,10 +728,10 @@ while test $# != 0; do
   --init=*) cmake_init_file=`cmake_arg "$1"` ;;
   --system-libs) cmake_bootstrap_system_libs="${cmake_bootstrap_system_libs} -DCMAKE_USE_SYSTEM_LIBRARIES=1" ;;
   --no-system-libs) cmake_bootstrap_system_libs="${cmake_bootstrap_system_libs} -DCMAKE_USE_SYSTEM_LIBRARIES=0" ;;
-  --system-bzip2|--system-curl|--system-expat|--system-jsoncpp|--system-libarchive|--system-zlib|--system-liblzma)
+  --system-bzip2|--system-curl|--system-expat|--system-jsoncpp|--system-libarchive|--system-librhash|--system-zlib|--system-liblzma)
     lib=`cmake_arg "$1" "--system-"`
     cmake_bootstrap_system_libs="${cmake_bootstrap_system_libs} -DCMAKE_USE_SYSTEM_LIBRARY_`cmake_toupper $lib`=1" ;;
-  --no-system-bzip2|--no-system-curl|--no-system-expat|--no-system-jsoncpp|--no-system-libarchive|--no-system-zlib|--no-system-liblzma)
+  --no-system-bzip2|--no-system-curl|--no-system-expat|--no-system-jsoncpp|--no-system-libarchive|--no-system-librhash|--no-system-zlib|--no-system-liblzma)
     lib=`cmake_arg "$1" "--no-system-"`
     cmake_bootstrap_system_libs="${cmake_bootstrap_system_libs} -DCMAKE_USE_SYSTEM_LIBRARY_`cmake_toupper $lib`=0" ;;
   --qt-gui) cmake_bootstrap_qt_gui="1" ;;