.ycm_extra_conf.py

import os
import ycm_core


def DirectoryOfThisScript():
    return os.path.dirname(os.path.abspath(__file__))


# This is the single most important line in this script. Everything else is just nice to have but
# not strictly necessary.
compilation_database_folder = DirectoryOfThisScript()

# This provides a safe fall-back if no compilation commands are available. You could also add a
# includes relative to your project directory, for example.
flags = [
    "-Wall",
    "-std=c++11",
    "-stdlib=libc++",
    "-x",
    "c++",
    "-I",
    ".",
    "-isystem",
    "/usr/local/include",
    "-isystem",
    "/usr/include",
    "-I.",
]

if compilation_database_folder:
    database = ycm_core.CompilationDatabase(compilation_database_folder)
else:
    database = None

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


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_
        )

    else:
        relative_to = DirectoryOfThisScript()
        final_flags = MakeRelativePathsInFlagsAbsolute(flags, relative_to)

    return {"flags": final_flags, "do_cache": True}