Autocompletion plugin for c/c++ with specific header path?

Question

Is there a plugin which autocompletes C/C++ code from specific headers given in a specific path (i.e. /path/)?

If I include some headers from that path, I would get autocompletion from given header.

Answer 1

TL;DR: Set 'path' to include the path to your include files. In your example:

set path+=/path

---

Native completion from include files

Vim native completion is quite useful for C and C++ files, Vim can search for your include files and find candidate completion targets in them and the defaults in Vim are already pretty useful for Vim completion.

You can use the CTRL-X CTRL-I sequence to initiate keyword completion, completing keywords in the current and include files.

And CTRL-X CTRL-D to initiate define completion, completing macros and defines in the current and include files.

set path

The important option to customize for these is 'path', which tells Vim where to search for include files.

By default, Vim will search the directory where the file lives (if you're editing src/submodule/xyz.c, then it will search under src/submodule first), the system include directory (/usr/include) and the current directory (which might typically be the root of your project.)

You might want to add paths to this setting, basically any include path you're passing the compiler through a -I flag should be of interest here.

Other relevant settings

Also relevant are 'include' and 'define', which hold patterns (regexps) used to detect #include and #define directives used for the aforementioned completion commands.

Also 'includeexpr', which can be used to translate an include to a file name (useful for languages in which submodule paths are separated by . rather than /.)

These are already correctly set for C/C++ by default, so you typically don't need to set these unless you're working with a different language.

Other useful commands for include files

There are other commands that can become very useful once 'path' is set correctly to find your include files.

For instance, see include file search for commands such as [i and [d which will show you the first occurrence of a keyword (or a define) and will go inside include files whenever it sees an #include directive. This can be quite powerful, as a quick way to check a function prototype wherever it's declared.

The gf command can be used from an #include line to open that header file. The :find command can be used to open an include file (or really any file under 'path') by name.