Add CMake Build Output Options

Add two new options to CMakeLists.txt:

`BUILD_SHARED` - Whether or not to build the shared object (Default: ON)
`BUILD_STATIC` - Whether or not to build the static archive (Default: ON)

CMakeLists.txt

@@ -290,7 +290,6 @@ if (LIBZMQ_WERROR)
   zmq_check_cxx_flag_prepend ("-errwarn=%all")
 endif ()
 
-
 if (CMAKE_SYSTEM_PROCESSOR MATCHES "^sparc")
   zmq_check_cxx_flag_prepend ("-mcpu=v9")
 endif ()
@@ -724,8 +723,21 @@ endif ()
 
 #-----------------------------------------------------------------------------
 # output
+option(BUILD_SHARED "Whether or not to build the shared object"  ON)
+option(BUILD_STATIC "Whether or not to build the static archive" ON)
+
+list(APPEND target_outputs "")
+
+if (BUILD_SHARED)
+  list(APPEND target_outputs "zmq-shared")
+endif()
+
+if (BUILD_STATIC)
+  list(APPEND target_outputs "zmq-static")
+endif()
 
 if (MSVC)
+  if (BUILD_SHARED)
     add_library (zmq-shared SHARED ${sources} ${public_headers} ${html-docs} ${readme-docs} ${CMAKE_CURRENT_BINARY_DIR}/NSIS.template.in)
     target_link_libraries (zmq-shared ${OPTIONAL_LIBRARIES})
     set_target_properties (zmq-shared PROPERTIES
@@ -736,6 +748,9 @@ if (MSVC)
       RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin"
       COMPILE_DEFINITIONS "DLL_EXPORT"
       OUTPUT_NAME "libzmq")
+  endif()
+  
+  if (BUILD_STATIC)
     add_library (zmq-static STATIC ${sources})
     set_target_properties (zmq-static PROPERTIES
       PUBLIC_HEADER "${public_headers}"
@@ -744,7 +759,9 @@ if (MSVC)
       DEBUG_POSTFIX "${MSVC_TOOLSET}-mt-sgd-${ZMQ_VERSION_MAJOR}_${ZMQ_VERSION_MINOR}_${ZMQ_VERSION_PATCH}"
       COMPILE_FLAGS "/DZMQ_STATIC"
       OUTPUT_NAME "libzmq")
+  endif()
 else ()
+  if (BUILD_SHARED)
     add_library (zmq-shared SHARED ${sources} ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig})
     # NOTE: the SOVERSION MUST be the same as the one generated by libtool!
     set_target_properties (zmq-shared PROPERTIES
@@ -767,6 +784,9 @@ else ()
       set_source_files_properties (${zmq-pkgconfig} PROPERTIES
                                   MACOSX_PACKAGE_LOCATION lib/pkgconfig)
     endif ()
+  endif()
+
+  if (BUILD_STATIC)
     add_library (zmq-static STATIC ${sources} ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig})
     set_target_properties (zmq-static PROPERTIES
       PUBLIC_HEADER "${public_headers}"
@@ -774,8 +794,9 @@ else ()
       OUTPUT_NAME "zmq"
       PREFIX "lib")
   endif()
+endif ()
 
-foreach (target zmq-shared zmq-static)
+foreach (target ${target_outputs})
   target_include_directories (${target}
     PUBLIC
       $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
@@ -784,6 +805,7 @@ foreach (target zmq-shared zmq-static)
   )
 endforeach()
 
+if (BUILD_SHARED)
   target_link_libraries (zmq-shared ${CMAKE_THREAD_LIBS_INIT})
 
   if (SODIUM_FOUND)
@@ -806,7 +828,9 @@ endif ()
   if (RT_LIBRARY)
     target_link_libraries (zmq-shared ${RT_LIBRARY})
   endif ()
+endif ()
 
+if (BUILD_SHARED)
   set (perf-tools local_lat
                  remote_lat
                  local_thr
@@ -845,6 +869,9 @@ if (WITH_PERF_TOOL)
       endif ()
     endforeach ()
   endif ()
+elseif (WITH_PERF_TOOL)
+  message(FATAL_ERROR "Shared library disabled - perf-tools unavailable.")
+endif ()
 
 #-----------------------------------------------------------------------------
 # tests
@@ -862,14 +889,14 @@ endif ()
 include(GNUInstallDirs)
 
 if (MSVC)
-  install (TARGETS zmq-shared zmq-static
+  install (TARGETS ${target_outputs}
           EXPORT ${PROJECT_NAME}-targets
           ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
           LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
           PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
           COMPONENT SDK)
   if (CMAKE_BUILD_TYPE STREQUAL "Debug")
-    install (TARGETS zmq-shared zmq-static
+    install (TARGETS ${target_outputs}
             RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
             ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
             PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
@@ -878,14 +905,14 @@ if (MSVC)
       install (FILES ${CMAKE_CURRENT_BINARY_DIR}/bin/libzmq${MSVC_TOOLSET}-mt-gd-${ZMQ_VERSION_MAJOR}_${ZMQ_VERSION_MINOR}_${ZMQ_VERSION_PATCH}.pdb DESTINATION lib
             COMPONENT SDK)
     endif ()
-  else ()
+  elseif (BUILD_SHARED)
     install (TARGETS zmq-shared
             RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
             PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
             COMPONENT Runtime)
   endif ()
 else ()
-  install (TARGETS zmq-shared zmq-static
+  install (TARGETS ${target_outputs}
           EXPORT ${PROJECT_NAME}-targets
           RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
           ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}