text: # Copyright (C) 2014 Google Inc.
  #
  # This file is part of ycmd.
  #
  # ycmd is free software: you can redistribute it and/or modify
  # it under the terms of the GNU General Public License as published by
  # the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.
  #
  # ycmd is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU General Public License
  # along with ycmd.  If not, see <http://www.gnu.org/licenses/>.
  
  import os
  import ycm_core
  
  # These are the compilation flags that will be used in case there's no
  # compilation database set (by default, one is not set).
  # CHANGE THIS LIST OF FLAGS. YES, THIS IS THE DROID YOU HAVE BEEN LOOKING FOR.
  flags = [
  '-Wall',
  '-Wextra',
  '-Werror',
  '-fexceptions',
  '-DDEBUG',
  # THIS IS IMPORTANT! Without a "-std=<something>" flag, clang won't know which
  # language to use when compiling headers. So it will guess. Badly. So C++
  # headers will be compiled as C headers. You don't want that so ALWAYS specify
  # a "-std=<something>".
  # For a C project, you would set this to something like 'c99' instead of
  # 'c++11'.
  '-std=c++11',
  '-stdlib=libc++',
  # ...and the same thing goes for the magic -x option which specifies the
  # language that the files to be compiled are written in. This is mostly
  # relevant for c++ headers.
  # For a C project, you would set this to 'c' instead of 'c++'.
  '-x', 'c++',
  '-isystem', '/usr/include/c++/5/',
  '-isystem', '/usr/include/x86_64-linux-gnu/c++/5/',
  '-isystem', '/usr/include/c++/4.9/',
  '-isystem', '/usr/include/x86_64-linux-gnu/c++/4.9/',
  '-isystem', '/usr/include/c++/4.8/',
  '-isystem', '/usr/include/x86_64-linux-gnu/c++/4.8/',
  '-isystem', '/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include',
  '-isystem', '/System/Library/Frameworks/Python.framework/Headers',
  '-isystem', '../llvm/include',
  '-isystem', '../llvm/tools/clang/include',
  '-isystem', '/usr/include',
  '-isystem', '/usr/local/include',
  '-I', '/usr/local/opt/openssl/include',
  '-I', './googletest/googletest/include',
  '-I', './src',
  ]
  
  
  # 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.
  compilation_database_folder = ''
  
  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 )
  
  
  # This is the entry point; this function is called by ycmd to produce flags for
  # a file.
  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_ )
    else:
      relative_to = DirectoryOfThisScript()
      final_flags = MakeRelativePathsInFlagsAbsolute( flags, relative_to )
  
    return {
      'flags': final_flags,
      'do_cache': True
    }
  
  