import os

import ycm_core

flags = [

'-Wall',

'-Wextra',

'-Werror',

'-x', 'c',

'-Iinclude',

]

# Set this to the absolute path to the folder (NOT the file!) containing the

# compile_commands.json file to use that instead of 'flags'. See here for

# more details: http://clang.llvm.org/docs/JSONCompilationDatabase.html

#

# Most projects will NOT need to set this to anything; you can just change the

# 'flags' list of compilation flags. Notice that YCM itself uses that approach.

compilation_database_folder = 'obj'

if os.path.exists( compilation_database_folder ):

  database = ycm_core.CompilationDatabase( compilation_database_folder )

else:

  database = None

SOURCE_EXTENSIONS = [ '.cpp', '.cxx', '.cc', '.c', '.m', '.mm' ]

def DirectoryOfThisScript():

  return os.path.dirname( os.path.abspath( __file__ ) )

def MakeRelativePathsInFlagsAbsolute( flags, working_directory ):

  if not working_directory:

    return list( flags )

  new_flags = []

  make_next_absolute = False

  path_flags = [ '-isystem', '-I', '-iquote', '--sysroot=' ]

  for flag in flags:

    new_flag = flag

    if make_next_absolute:

      make_next_absolute = False

      if not flag.startswith( '/' ):

        new_flag = os.path.join( working_directory, flag )

    for path_flag in path_flags:

      if flag == path_flag:

        make_next_absolute = True

        break

      if flag.startswith( path_flag ):

        path = flag[ len( path_flag ): ]

        new_flag = path_flag + os.path.join( working_directory, path )

        break

    if new_flag:

      new_flags.append( new_flag )

  return new_flags

def IsHeaderFile( filename ):

  extension = os.path.splitext( filename )[ 1 ]

  return extension in [ '.h', '.hxx', '.hpp', '.hh' ]

def GetCompilationInfoForFile( filename ):

  # The compilation_commands.json file generated by CMake does not have entries

  # for header files. So we do our best by asking the db for flags for a

  # corresponding source file, if any. If one exists, the flags for that file

  # should be good enough.

  if IsHeaderFile( filename ):

    basename = os.path.splitext( filename )[ 0 ]

    for extension in SOURCE_EXTENSIONS:

      replacement_file = basename + extension

      if os.path.exists( replacement_file ):

        compilation_info = database.GetCompilationInfoForFile(

          replacement_file )

        if compilation_info.compiler_flags_:

          return compilation_info

    return None

  return database.GetCompilationInfoForFile( filename )

def FlagsForFile( filename, **kwargs ):

  if database:

    # Bear in mind that compilation_info.compiler_flags_ does NOT return a

    # python list, but a "list-like" StringVec object

    compilation_info = GetCompilationInfoForFile( filename )

    if not compilation_info:

      return None

    final_flags = MakeRelativePathsInFlagsAbsolute(

      compilation_info.compiler_flags_,

      compilation_info.compiler_working_dir_ )

    # NOTE: This is just for YouCompleteMe; it's highly likely that your project

    # does NOT need to remove the stdlib flag. DO NOT USE THIS IN YOUR

    # ycm_extra_conf IF YOU'RE NOT 100% SURE YOU NEED IT.

    try:

      final_flags.remove( '-stdlib=libc++' )

    except ValueError:

      pass

  else:

    relative_to = DirectoryOfThisScript()

    final_flags = MakeRelativePathsInFlagsAbsolute( flags, relative_to )

  return {

    'flags': final_flags,

    'do_cache': True

  }