Index: llvm/trunk/cmake/modules/CheckLinkerFlag.cmake
===================================================================
--- llvm/trunk/cmake/modules/CheckLinkerFlag.cmake
+++ llvm/trunk/cmake/modules/CheckLinkerFlag.cmake
@@ -0,0 +1,8 @@
+include(CheckCXXCompilerFlag)
+
+function(check_linker_flag flag out_var)
+  set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${flag}")
+  check_cxx_compiler_flag("" ${out_var})
+  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
+endfunction()
Index: llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
+++ llvm/trunk/cmake/modules/HandleLLVMOptions.cmake
@@ -597,6 +597,14 @@
   append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif()
 
+# lld doesn't print colored diagnostics when invoked from Ninja
+if (UNIX AND CMAKE_GENERATOR STREQUAL "Ninja")
+  include(CheckLinkerFlag)
+  check_linker_flag("-Wl,-color-diagnostics" LINKER_SUPPORTS_COLOR_DIAGNOSTICS)
+  append_if(LINKER_SUPPORTS_COLOR_DIAGNOSTICS "-Wl,-color-diagnostics"
+    CMAKE_EXE_LINKER_FLAGS CMAKE_MODULE_LINKER_FLAGS CMAKE_SHARED_LINKER_FLAGS)
+endif()
+
 # Add flags for add_dead_strip().
 # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF?
 # But MinSizeRel seems to add that automatically, so maybe disable these