deoplete-clang2
   ^{Electric Boogaloo}

This is a clang completer for deoplete.nvim that's faster than deoplete-clang. Instead of using libclang, it just uses clang -cc1 like most other clang plugins. Unlike other plugins, Objective-C was given a little more attention.

If you are like me, you:

• want completions to be relatively easy to setup
• are not entirely sure how to use clang -cc1
• just want the damned completions
  • for Objective-C
    • with the ability to fill in method arguments without having an aneurysm
    • and type ] to wrap method calls (within reason)
      • (you also think Xcode's method of doing this sucks)
    • also, magically get completions for the MacOSX SDKs
      • without Xcode
        • on Linux

This was developed mainly to scratch an old itch. I'm currently not committed to continuing development beyond fixing obvious bugs. Pull requests to add useful features are welcome, though.

With that said, you may want to keep an eye on clang-server that @zchee is working on.

Requirements

• Neovim with Python 3 configured
• deoplete.nvim
• clang

I'm using clang 3.8.0. Lower versions may work, but are untested.

Install

Follow your package manager's instructions.

Usage

Completions will insert functions with argument placeholders in the form of <#Type var#>. While the cursor is on a line with one of these placeholders, pressing <tab> will enter select mode with the next placeholder selected. Pressing <tab> again will move to the next placeholder and pressing <s-tab> will cycle backwards.

In Objective-C sources, pressing ] will try to place a [ in the appropriate place. While it isn't perfect, it's a whole lot better than how Xcode works. You will have the best results by avoiding nested multi-argument method calls.

Config

Note: For simple projects, you probably don't need to configure anything. You definitely shouldn't need to configure anything if your project uses a compilation database.

Create a .clang file at your project root. You should be able to just paste most of your compile flags in there (the parts that make sense at least). Mainly, it should have the relevant -I, -D, -F flags. The plugin will try to fill in the blanks for system include paths and discard the flags that are causing completions to not work.

You can also use let g:deoplete#sources#clang#flags = ['-Iwhatever', ...] in your nvim configs.

g:deoplete#sources#clang#executable sets the path to the clang executable.

g:deoplete#sources#clang#autofill_neomake is a boolean that tells this plugin to fill in the g:neomake_<filetype>_clang_maker variable with the clang executable path and flags. You will still need to enable it with g:neomake_<filetype>_enabled_makers = ["clang"].

g:deoplete#sources#clang#std is a dict containing the standards you want to use. It's not used if you already have -std=whatever in your flags. The defaults are:

{
    'c': 'c11',
    'cpp': 'c++1z',
    'objc': 'c11',
    'objcpp': 'c++1z',
}

g:deoplete#sources#clang#preproc_max_lines sets the maximum number of lines to search for a #ifdef or #endif line. #ifdef lines are discarded to get completions within conditional preprocessor blocks. The default is 50, setting it to 0 disables this feature.

MacOSX10._ SDK completions

(You may find it funny that I haven't tested this on macOS)

Just add -darwin=10.XX to your flags (where XX is the release, e.g. 10.8). It will be turned into the following flags:

-D__MACH__
-D__MAC_OS_X_VERSION_MAX_ALLOWED=10XX
-D__APPLE_CPP__
-DTARGET_CPU_X86_64
-fblocks
-fasm-blocks
-fno-builtin
-isysroot<sdk_path>
-iframework<sdk_path>/System/Library/Frameworks
-isystem<sdk_path>/usr/include

The above is the minimum flags to get SDK completions without clang spewing a litany of errors. If you're working on a simple project, -darwin=10.XX should be the only flag you need.

On macOS, the following directories are searched for the SDK:

• /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs
• /Developer/SDKs
• ~/Library/Developer/Frameworks (download destination)

On non-macOS:

• $XDG_DATA_HOME/SDKs or ~/.local/share/SDKs (download destination)

If the SDK is not found on the system or SDK paths, it will be downloaded from phracker/MacOSX-SDKs in the background.