一、简介
YouCompleteMe是Vim的自动补全插件，与同类插件相比，具有如下优势
1、基于语义补全
2、整合实现了多种插件
clang_complete、AutoComplPop 、Supertab 、neocomplcache 、Syntastic(类似功能,仅仅针对c/c++/obj-c代码)
3、支持多种语言
c、c++、obj-c、c#、python
对于其他的语言，会调用vim设置的omnifunc来匹配，因此同样支持php,ruby等语言。
4、YouCompleteMe除了提供了自动补全、自动提示错误的功能外,还提供了类似tags的功能
跳转到定义GoToDefinition
跳转到声明GoToDeclaration
以及两者的合体GoToDefinitionElseDeclaration
科普
Vim作为一款文本编辑器，针对文本自动补全这个功能来说，主要有两种实现方式：
基于文本(acp,omnicppcompleter)
我们常用的omnicppcompleter,acp,vim自带的c-x, c-n的实现方式就是基于文本。更通俗的说法，其实就是一个字：猜
其通过文本进行一些正则表达式的匹配，再根据生成的tags(利用ctags生成)来实现自动补全的效果。
基于语义
顾名思义，其是通过分析源文件，经过语法分析以后进行补全。由于对源文件进行分析，基于语义的补全可以做到很精确。但是这显然是vim所不可能支持的。而且经过这么多年发展，由于语法分析有很高的难度，也一直没有合适的工具出现。直到，由apple支持的clang/llvm横空出世。YouCompleteMe也正是在clang/llvm的基础上进行构建的。
二、安装
1、方式1：基于vundle
使用vundle进行安装，在.vimrc中添加如下代码
Bundle 'Valloric/YouCompleteMe'
保存退出后打开vim，在正常模式下输入
:BundleInstall
等待vundle将YouCompleteMe安装完成，而后需要进行编译安装
cd ~/.vim/bundle/YouCompleteMe
./install.sh --clang-completer
提示：如果不需要c-family的补全，可以去掉--clang-completer。如果需要c#的补全，请加上--omnisharp-completer.
可能出现的报错：
解决办法
yum install cmake
2、方式2：基于spf13-vim
在用户主目录下，编辑文件（若没有，则新建）：.vimrc.before.local
vim .vimrc.before.local
#添加如下内容
let g:spf13_bundle_groups['general', 'writing', 'neocomplcache', 'programming', 'php', 'ruby', 'python', 'javascript', 'html', 'misc', 'youcompleteme', ]
保存退出后打开vim，在正常模式下输入，等待YouCompleteMe安装完成，进行编译安装即可
:BundleInstall
三、配置
YouCompleteMe首先需要编译，另外还需要有配置。在vim启动后，YouCompleteMe会找寻当前路径以及上层路径的.ycm_extra_conf.py.在~/.vim/bundle/YouCompleteMe/cpp/ycm/.ycm_extra_conf.py中提供了默认的模板。也可以参考我的(就在模板上改改而已)。不过这个解决了标准库提示找不到的问题。
一般来说,我会在~目录下放一个默认的模板，而后再根据不同的项目在当前目录下再拷贝个.ycm_extra_conf.py.
# This file is NOT licensed under the GPLv3, which is the license for the rest
# of YouCompleteMe.
#
# Here's the license text for this file:
#
# This is free and unencumbered software released into the public domain.
#
# Anyone is free to copy, modify, publish, use, compile, sell, or
# distribute this software, either in source code form or as a compiled
# binary, for any purpose, commercial or non-commercial, and by any
# means.
#
# In jurisdictions that recognize copyright laws, the author or authors
# of this software dedicate any and all copyright interest in the
# software to the public domain. We make this dedication for the benefit
# of the public at large and to the detriment of our heirs and
# successors. We intend this dedication to be an overt act of
# relinquishment in perpetuity of all present and future rights to this
# software under copyright law.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
# For more information, please refer to <http://unlicense.org/>
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',
#'-Wc++98-compat',
'-Wno-long-long',
'-Wno-variadic-macros',
'-fexceptions',
'-stdlib=libc++',
# 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',
# ...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++',
'-I',
'.',
'-isystem',
'/usr/include',
'-isystem',
'/usr/local/include',
'-isystem',
'/Library/Developer/CommandLineTools/usr/include',
'-isystem',
'/Library/Developer/CommandLineTools/usr/bin/../lib/c++/v1',
]
# 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 = ''
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
}
在.vimrc中对YouCompleteMe的配置如下
" YouCompleteMe配置
let g:ycm_error_symbol = '>>'
let g:ycm_warning_symbol = '>*'
nnoremap <leader>gl :YcmCompleter GoToDeclaration<CR>
nnoremap <leader>gf :YcmCompleter GoToDefinition<CR>
nnoremap <leader>gg :YcmCompleter GoToDefinitionElseDeclaration<CR>
nmap <F4> :YcmDiags<CR>
提示：YouCompleteMe提供的跳跃功能采用了vim的jumplist，往前跳和往后跳的快捷键为Ctrl+O以及Ctrl+I