Added option FLATBUFFERS_BUILD_FLATC

When FLATBUFFERS_BUILD_FLATC is set to OFF, the flatbuffer compiler
and tests will not be build.

Change-Id: I42b87b71daab4cb9c06605c813e7e4b62d6bf67a

CMakeLists.txt

@@ -6,6 +6,13 @@ project(FlatBuffers)
 option(FLATBUFFERS_CODE_COVERAGE "Enable the code coverage build option." OFF)
 option(FLATBUFFERS_BUILD_TESTS "Enable the build of tests and samples." ON)
 option(FLATBUFFERS_INSTALL "Enable the installation of targets." ON)
+option(FLATBUFFERS_BUILD_FLATC "Enable the build of the flatbuffers compiler" ON)
+
+if(NOT FLATBUFFERS_BUILD_FLATC AND FLATBUFFERS_BUILD_TESTS)
+    message(WARNING
+    "Cannot build tests without building the compiler. Tests will be disabled.")
+    set(FLATBUFFERS_BUILD_TESTS OFF)
+endif()
 
 set(FlatBuffers_Compiler_SRCS
   include/flatbuffers/flatbuffers.h
@@ -69,7 +76,9 @@ endif()
 
 include_directories(include)
 
+if(FLATBUFFERS_BUILD_FLATC)
 add_executable(flatc ${FlatBuffers_Compiler_SRCS})
+endif()
 
 function(compile_flatbuffers_schema_to_cpp SRC_FBS)
   get_filename_component(SRC_FBS_DIR ${SRC_FBS} PATH)
@@ -93,7 +102,9 @@ endif()
 
 if(FLATBUFFERS_INSTALL)
   install(DIRECTORY include/flatbuffers DESTINATION include)
-  install(TARGETS flatc DESTINATION bin)
+  if(FLATBUFFERS_BUILD_FLATC)
+    install(TARGETS flatc DESTINATION bin)
+  endif()
 endif()
 
 if(FLATBUFFERS_BUILD_TESTS)