test/com/facebook/buck/cxx/testdata/preprocessing_per_file_flags/BUCK

cxx_binary(
  name = 'bin',
  srcs = {
    'main.cpp': 'main.cpp',
    'file_one.cpp': ('file.cpp', ['-DFUNCTION_NAME=oneFunction']),
    'file_another.cpp': ('file.cpp', ['-DFUNCTION_NAME=anotherFunction']),
  },
  headers = [
    'file.h'
  ],
)