Merge pull request #2513 from ethereum/cmake_llvm_version

LLVM version requirements in cmake

evmjit/CMakeLists.txt

@@ -25,8 +25,11 @@ if (${CMAKE_SYSTEM_NAME} STREQUAL "Linux" AND NOT LLVM_DIR)
 	add_definitions(-D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS)
 	link_directories(/usr/lib/llvm-3.7/lib)
 else()
-	find_package(LLVM 3.7 REQUIRED CONFIG)
-	message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
+	find_package(LLVM REQUIRED CONFIG)
+	if (${LLVM_VERSION} VERSION_LESS 3.7)
+		message(FATAL_ERROR "Incompatible LLVM version ${LLVM_VERSION}")
+	endif()
+	message(STATUS "Found LLVM ${LLVM_VERSION}")
 	message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")
 	add_definitions(${LLVM_DEFINITIONS})
 	llvm_map_components_to_libnames(LLVM_LIBS core support mcjit x86asmparser x86codegen ipo)