VIM - Sourcing tags from multiple locations in project

Question

Good day,

I typically work on relatively small (less than 20,000 lines of code) projects that are all self contained within a single directory, have their own Makefile, and are fairly easy to work with.

VIM is my preferred editor, and when I open a project, I typically build the ctags list via a mapping to the F10 key:

map <F10> :!ctags -R --c++-kinds=+p --fields=+iaS --extra=+q .<CR>

This allows me to jump to the definition of a variable/struct/etc via moving the cursor over the text, and hitting CTRL+], as well as using code completion with a drop-down list via OmniCppComplete.

However, I am now working on a slightly larger project which makes use of LOTS of structures. Furthermore, many of these structures have arrays of other custom structures as members, so code completion is a very useful and important tool for me right now.

I have two paths that include a lot of .C files and .h files, and they may change from machine to machine. On each machine, however, we have an environment variable in our .bashrc file that points to them like so:

SDK_SRC_PLUS_HEADERS=/public/sdk
THIRD_PARTY_SDK=/private/sdk

I would like to be able to have VIM automatically refer to the contents of these additional paths when I attempt to do code completion (via VIM's built-in OmniCppComplete feature), or to jump to the files in these locations when I use CTRL+] in VIM to jump to the definition of a struct, function, variable, etc.

So, for both of the above paths, I cd into them, and generate the tags via ctags -R. Then, I modified my ~/.vimrc file to include additional tags paths, like so:

tags=./tags
tags+=$SDK_SRC_PLUS_HEADERS/tags
tags+=$THIRD_PARTY_SDK/tags

I then cd into my project at /home/user1/projects/test, start VIM, and hit F10 in VIM to index it. However, this does not work at all. In fact, it breaks my ability to even use tags just for the project itself (ie: CTRL+] now does nothing).

Does anyone have any suggestions on how I could have code completion source tags and jump-to-definitions using multiple source directories via environment variables?

Thank you all in advance for your time and assistance!

Answer 1

It indeed appears to be the problem that you can't use environment variables inside the tags setting.

I came up with this as a workaround:

:let &tags.=expand(",$SDK_SRC_PLUS_HEADERS/tags")

This might be slightly more friendly:

:exec expand("set tags+=$SDK_SRC_PLUS_HEADERS/tags")

Answer 2

I wanted to add to the solution provided by @sehe.

This is the final set of changes I made to my .vimrc. The first lines are for adding expanded environment variable paths to my tags variable. The other is for auto-updating tags in the event that I have to update my SDK and don't want to be able to accidentally use out-of-date tags:

" CTAGS tag generation for OmniCppComplete
set tags+=./tags
exec expand("set tags+=$SDK_SRC_PLUS_HEADERS/tags")
exec expand("set tags+=$THIRD_PARTY_SDK/tags")
" Can verify taglist is correct via ":set verbose tags?" command

" Create a mapping to delete the old tags, re-generate them, and use them
map <F10> :!ctags -R --c++-kinds=+p --fields=+iaS --extra=+q . \| rm -f $SDK_SRC_PLUS_HEADERS/tags \| ctags -R -f $SDK_SRC_PLUS_HEADERS/tags $SDK_SRC_PLUS_HEADERS/tags  \| rm -f $THIRD_PARTY_SDK/tags \| ctags -R -f $THIRD_PARTY_SDK/tags $THIRD_PARTY_SDK/tags  \| echo "Done re-generating tags."<CR>