Strahinja Val Markovic 421e15f1e1 Readme rewording

2013-01-25 14:50:45 -08:00

18 KiB

Raw Blame History

YouCompleteMe: a code-completion engine for Vim

YouCompleteMe is a fast, as-you-type, fuzzy-search code completion engine for Vim. It has two completion engines: an identifier-based engine that works with every programing language and a semantic, Clang-based engine that provides semantic code completion for C/C++/Objective-C/Objective-C++ (from now on referred to as "the C-family languages").

Mac OS X super-quick installation

Please refer to the full Installation Guide below; the following commands are provided on a best-effort basis and may not work for you.

Install the latest version of MacVim. Yes, MacVim. And yes, the latest.

Install YouCompleteMe with Vundle.

Install CMake. Preferably with Homebrew, but here's the stand-alone CMake installer.

If you care about semantic completion for C-family languages, type in the following commands in the console. If you don't, skip this step.

cd ~
mkdir ycm_temp
cd ycm_temp
curl -O http://llvm.org/releases/3.2/clang+llvm-3.2-x86_64-apple-darwin11.tar.gz
tar -zxvf clang+llvm-3.2-x86_64-apple-darwin11.tar.gz
cp clang+llvm-3.2-x86_64-apple-darwin11/lib/libclang.dylib ~/.vim/bundle/YouCompleteMe/python

Compiling YCM with semantic support for C-family languages (previous step required):

cd ~
makedir ycm_build
cd ycm_build
cmake -G "Unix Makefiles" -DPATH_TO_LLVM_ROOT=~/ycm_temp/clang+llvm-3.2-x86_64-apple-darwin11 . ~/.vim/bundle/YouCompleteMe/cpp
make ycm_core

Compiling YCM without semantic support for C-family languages:

cd ~
makedir ycm_build
cd ycm_build
cmake -G "Unix Makefiles" . ~/.vim/bundle/YouCompleteMe/cpp
make ycm_core

That's it. You're done. Refer to the User Guide section on how to use YCM. Don't forget that if you want the C-family semantic completion engine to work, you will need to provide the compilation flags for your project to YCM. It's all in the User Guide.

YCM comes with sane defaults for its options, but you still may want to take a look at what's available for configuration. There are a few interesting options that are conservatively turned off by default that you may want to turn on.

Ubuntu Linux x64 super-quick installation

Please refer to the full Installation Guide below; the following commands are provided on a best-effort basis and may not work for you.

Make sure you have Vim 7.3.584 with python2 support. At the time of writing, the version of Vim shipping with Ubuntu is too old. You may need to compile Vim from source.

Install YouCompleteMe with Vundle.

Install CMake. sudo apt-get instal cmake

If you care about semantic completion for C-family languages, type in the following commands in the console. If you don't, skip this step.

cd ~
mkdir ycm_temp
cd ycm_temp
curl -O http://llvm.org/releases/3.2/clang+llvm-3.2-x86_64-linux-ubuntu-12.04.tar.gz
tar -zxvf clang+llvm-3.2-x86_64-linux-ubuntu-12.04.tar.gz
cp clang+llvm-3.2-x86_64-linux-ubuntu-12.04/lib/libclang.so ~/.vim/bundle/YouCompleteMe/python

Compiling YCM with semantic support for C-family languages (previous step required):

cd ~
mkdir ycm_build
cd ycm_build
cmake -G "Unix Makefiles" -DPATH_TO_LLVM_ROOT=~/ycm_temp/clang+llvm-3.2-x86_64-linux-ubuntu-12.04 . ~/.vim/bundle/YouCompleteMe/cpp
make ycm_core

Compiling YCM without semantic support for C-family languages:

cd ~
mkdir ycm_build
cd ycm_build
cmake -G "Unix Makefiles" . ~/.vim/bundle/YouCompleteMe/cpp
make ycm_core

Full Installation Guide

These are the steps necessary to get YCM working on a Unix OS like Linux or Mac OS X. My apologies to Windows users, but I don't have a guide for them. The code is platform agnostic, so if everything is configured correctly, YCM should work on Windows without issues (but as of writing, it's untested on that platform).

Please follow the instructions carefully:

Ensure that your version of Vim is at least 7.3.584 and that it has support for python2 scripting.

Inside Vim, type :version. Look at the first two to three lines of output; it should say Vi IMproved 7.3 and then below that, Included patches: 1-X, where X will be some number. That number needs to be 584 or higher.

After you have made sure that you have Vim 7.3.584+, type the following in Vim: :has('python'). The output should be 1. If it's 0, then get a version of Vim with Python support.
Install YCM with Vundle (or Pathogen, but Vundle is a better idea). With Vundle, this would mean adding a Bundle 'Valloric/YouCompleteMe' line to your vimrc.
[Complete this step ONLY if you care about semantic completion support for C-family languages. Otherwise it's not neccessary.]

Download the latest version of libclang. Clang is an open-source compiler that can compile C/C++/Objective-C/Objective-C++. The libclang library it provides is used to power the YCM semantic completion engine for those languages. YCM needs libclang version 3.2 or higher.

You can use the system libclang only if you are sure it is version 3.2 or higher, otherwise don't. Even if it is, I recommend using the official binaries from llvm.org if at all possible. Make sure you download the correct archive file for your OS.
Compile the ycm_core plugin plugin (ha!) that YCM needs. This is the C++ engine that YCM uses to get fast completions.

You will need to have cmake installed in order to generate the required makefiles. Linux users can install cmake with their package manager (sudo apt-get install cmake for Ubuntu) whereas other users can download and install cmake from its project site. Mac users can also get it through Homebrew with brew install cmake.

Here we'll assume you installed YCM with Vundle. That means that the top-level YCM directory is in ~/.vim/bundle/YouCompleteMe.

We'll create a new folder where build files will be placed. Run the following:
```
cd ~
mkdir ycm_build
cd ycm_build
```
Now we need to generate the makefiles. If you DON'T care about semantic support for C-family languages, run the following command in the ycm_build directory: cmake -G "Unix Makefiles" . ~/.vim/bundle/YouCompleteMe/cpp

If you DO care about semantic support for C-family languages, then your cmake call will be a bit more complicated. We'll assume you downloaded a binary distribution of LLVM+Clang from llvm.org in step 3 and that you extracted the archive file to folder ~/ycm_temp/llvm_root_dir (with bin, lib, include etc. folders right inside that folder). With that in mind, run the following command in the ycm_build directory: cmake -G "Unix Makefiles" -DPATH_TO_LLVM_ROOT=~/ycm_temp/llvm_root_dir . ~/.vim/bundle/YouCompleteMe/cpp

Now that makefiles have been generated, simply run make ycm_core.

For those who want to use the system version of libclang, you would pass -DUSE_SYSTEM_LIBCLANG=ON to cmake instead of the -DPATH_TO_LLVM_ROOT=... flag.

You could also force the use of a custom libclang library with -DEXTERNAL_LIBCLANG_PATH=/path/to/libclang.so flag (the library would end with .dylib on a Mac). Again, this flag would be used instead of the other flags.
[Complete this step ONLY if you care about semantic completion support for C-family languages. Otherwise it's not neccessary.]

Copy the libclang library file into the YouCompleteMe/python folder. The library file is libclang.so on Linux and libclang.dylib on Mac.

We'll assume you downloaded a binary distribution of LLVM+Clang from llvm.org in step 3 and that you extracted the archive file to folder ~/ycm_temp/llvm_root_dir (with bin, lib, include etc. folders right inside that folder).

We'll also assume you installed YCM with Vundle. That means that the top-level YCM directory is in ~/.vim/bundle/YouCompleteMe.

On Linux, run: cp ~/ycm_temp/llvm_root_dir/lib/libclang.so ~/.vim/bundle/YouCompleteMe/python

On Mac, run: cp ~/ycm_temp/llvm_root_dir/lib/libclang.dylib ~/.vim/bundle/YouCompleteMe/python

User Guide

TODO, still WIP

General Usage

If the offered completions are too broad, keep typing characters; YCM will continue refining the offered completions based on your input.
Use the TAB key to accept a completion and continue pressing TAB to cycle through the completions. Use Ctrl+TAB to cycle backwards.

Semantic Completion Engine Usage

You can use Ctrl+Space to trigger the completion suggestions anywhere, even without a string prefix. This is useful to see which top-level functions are available for use.
You really also want to install the latest version of the Syntastic Vim plugin. It has support for YCM and together they will provide you with compile errors/warnings practically instantly and without saving the file.

YCM looks for a .ycm_extra_conf.py file in the directory of the opened file or in any directory above it in the hierarchy (recursively); when the file is found, it is loaded (only once!) as a Python module. YCM calls a FlagsForFile method in that module which should provide it with the information necessary to compile the current file.

This system was designed this way so that the user can perform any arbitrary sequence of operations to produce a list of compilation flags YCM should hand to Clang.

See YCM's own .ycm_extra_conf.py for details on how this works. You should be able to use it as a starting point. Hint: just replace the strings in the flags variable with compilation flags necessary for your project. That should be enough for 99% of projects.

Yes, Clang's CompilationDatabase system is also supported. Again, see the above linked example file.

TODO: compile flags, include paths, ycm_extra_conf, CompilationDatabase support, how the search system works (subsequence match), extending the semantic engine for other langs, using ListToggle

Options

All options have reasonable defaults so if the plug-in works after installation you don't need to change any options. These options can be configured in your vimrc script by including a line like this:

let g:ycm_min_num_of_chars_for_completion = 1

Note that after changing an option in your [vimrc script] vimrc you have to restart Vim for the changes to take effect.

The `g:ycm_min_num_of_chars_for_completion` option

This option controls the number of characters the user needs to type before completion suggestions are triggered. For example, if the option is set to 2, then when the user types a second alphanumeric character after a whitespace character, completion suggestions will be triggered.

Default: 2

let g:ycm_min_num_of_chars_for_completion = 2

The `g:ycm_filetypes_to_completely_ignore` option

This option controls for which Vim filetypes (see :h filetype) should YCM be turned off. The option value should be a Vim dictionary with keys being filetype strings (like python, cpp etc) and values being unimportant (the dictionary is used like a hash set, meaning that only the keys matter). The listed filetypes will be completely ignored by YCM, meaning that neither the identifier-based completion engine nor the semantic engine will operate in files of those filetypes.

You can get the filetype of the current file in Vim with :set ft?.

Default: {notes: 1, markdown: 1, text: 1}

let g:ycm_filetypes_to_completely_ignore = {
      \ 'notes' : 1,
      \ 'markdown' : 1,
      \ 'text' : 1,
      \}

The `g:ycm_filetype_specific_completion_to_disable` option

This option controls for which Vim filetypes (see :h filetype) should the YCM semantic completion engine be turned off. The option value should be a Vim dictionary with keys being filetype strings (like python, cpp etc) and values being unimportant (the dictionary is used like a hash set, meaning that only the keys matter). The listed filetypes will be ignored by the YCM semantic completion engine, but the identifier-based completion engine will still trigger in files of those filetypes.

Note that even if semantic completion is not turned off for a specific filetype, you will not get semantic completion if the semantic engine does not support that filetype. Currently, the semantic engine only supports the c, cpp, objc and objcpp filetypes.

You can get the filetype of the current file in Vim with :set ft?.

Default: {}

let g:ycm_filetype_specific_completion_to_disable = {}

The `g:ycm_allow_changing_updatetime` option

When this option is set to 1, YCM will change the updatetime Vim option to 2000 (see :h updatetime). This may conflict with some other plugins you have (but it's unlikely). The updatetime option is the number of milliseconds that have to pass before Vim's CursorHold (see :h CursorHold) event fires. YCM runs the completion engines' "file comprehension" systems in the background on every such event; the identifier-based engine collects the identifiers whereas the semantic engine compiles the file to build an AST.

The Vim default of 4000 for updatetime is a bit long, so YCM reduces this. Set this option to 0 to force YCM to leave your updatetime setting alone.

Default: 1

let g:ycm_allow_changing_updatetime = 1

The `g:ycm_add_preview_to_completeopt` option

When this option is set to 1, YCM will add the preview string to Vim's completeopt option (see :h completeopt). If your completeopt option already has preview set, there will be no effect. You can see the current state of your completeopt setting with :set completeopt? (yes, the question mark is important).

When preview is present in completeopt, YCM will use the preview window at the top of the file to store detailed information about the current completion candidate (but only if the candidate came from the semantic engine). For instance, it would show the full function prototype and all the function overloads in the window if the current completion is a function name.

Default: 0

let g:ycm_add_preview_to_completeopt = 0

The `g:ycm_autoclose_preview_window_after_completion` option

When this option is set to 1, YCM will auto-close the preview window after the user accepts the offered completion string. If there is no preview window triggered because there is no preview string in completeopt, this option is irrelevant. See the g:ycm_add_preview_to_completeopt option for more details.

Default: 0

let g:ycm_autoclose_preview_window_after_completion = 0

The `g:ycm_max_diagnostics_to_display` option

This option controls the maximum number of diagnostics shown to the user when errors or warnings are detected in the file. This option is only relevant if you are using the semantic completion engine and have installed the version of the Syntastic plugin that supports YCM.

Default: 30

let g:ycm_max_diagnostics_to_display = 30

FAQ

I get a strange linker warning regarding `libpython` on Mac

If the warning is ld: warning: path '/usr/lib/libpython2.7.dylib' following -L not a directory, then feel free to ignore it; it's caused by a limitation of CMake and is not an issue. Everything should still work fine.

I get a weird window at the top of my file when I use the semantic engine

This is Vim's preview window. Vim uses it to show you extra information about something if such information is available. YCM provides Vim with such extra information. For instance, when you select a function in the completion list, the preview window will hold that function's prototype and the prototypes of any overloads of the function. It will stay there after you select the completion so that you can use the information about the parameters and their types to write the function call.

If you would like this window to auto-close after you select a completion string, set the g:ycm_autoclose_preview_window_after_completion option to 1 in your vimrc file.

If you don't want this window to ever show up, add set completeopt-=preview to your vimrc. Also make sure that the g:ycm_add_preview_to_completeopt option is set to 0.

Contact

If you have questions, bug reports, suggestions, etc. please use the [issue tracker][tracker]. The latest version is available at http://valloric.github.com/YouCompleteMe/.

The author's homepage is http://val.markovic.io.

18 KiB Raw Blame History

YouCompleteMe: a code-completion engine for Vim

Mac OS X super-quick installation

Ubuntu Linux x64 super-quick installation

Full Installation Guide

User Guide

General Usage

Semantic Completion Engine Usage

Options

The g:ycm_min_num_of_chars_for_completion option

The g:ycm_filetypes_to_completely_ignore option

The g:ycm_filetype_specific_completion_to_disable option

The g:ycm_allow_changing_updatetime option

The g:ycm_add_preview_to_completeopt option

The g:ycm_autoclose_preview_window_after_completion option

The g:ycm_max_diagnostics_to_display option

FAQ

I get a strange linker warning regarding libpython on Mac