Merge pull request #702 from jtattermusch/visual_studio_build_static_runtime

Link runtime statically for VS build

cmake/CMakeLists.txt

@@ -43,6 +43,19 @@ endif (HAVE_ZLIB)
 if (MSVC)
   if (BUILD_SHARED_LIBS)
     add_definitions(-DPROTOBUF_USE_DLLS)
+  else (BUILD_SHARED_LIBS)
+    # In case we are building static libraries, link also the runtime library statically
+	# so that MSVCR*.DLL is not required at runtime.
+    # https://msdn.microsoft.com/en-us/library/2kzt1wy3.aspx
+    # This is achieved by replacing msvc option /MD with /MT and /MDd with /MTd
+    # http://www.cmake.org/Wiki/CMake_FAQ#How_can_I_build_my_MSVC_application_with_a_static_runtime.3F
+    foreach(flag_var
+        CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
+        CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
+      if(${flag_var} MATCHES "/MD")
+        string(REGEX REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
+      endif(${flag_var} MATCHES "/MD")
+    endforeach(flag_var)
   endif (BUILD_SHARED_LIBS)
   add_definitions(/wd4244 /wd4267 /wd4018 /wd4355 /wd4800 /wd4251 /wd4996 /wd4146 /wd4305)
 endif (MSVC)