Including header files recursively for syntastic

I'm working with a C++ project and trying to configure it to use syntastic. In my project I have a nested directory structure of header files (The actual nested structure is much worse, this is an example).

--libs    
    |---dir1
         |---foo1.h    
    |---dir2
         |---foo2.h
         |---foo3.h
         |---dir3
               |---foo4.h

I have included the lib files in my .vimrc file using:

let g:syntastic_cpp_include_dirs = [ 'libs/']

I assumed this would take all the header files recursively, but it doesn't. In the code, syntastic complains with the error 'no such file or directory found'.

When I explicitly change the variable to refer to a specific directory:

let g:syntastic_cpp_include_dirs = [ 'libs/dir2/dir3/']

it works.

My questions:

1. How do you configure syntastic so that it includes header files of a set of directories recursively?
2. How do you do this for multiple projects? Always editing the .vimrc as I switch the project I'm working on doesn't sound right. I believe there must be a better way.

EDIT:

I didn't mention that in my .vimrc, the following options are present for syntastic:

let g:syntastic_check_on_open=1
let g:syntastic_enable_signs=1
let g:syntastic_cpp_include_dirs = ['libs/dir2/dir3', 'libs/dir2 ]
let g:syntastic_cpp_check_header = 1
let g:syntastic_cpp_remove_include_errors = 1

You can include all the directories to be searched for header files per project in the project root directory in a file .syntastic_cpp_config. The format for doing so would the same as providing the -I directives to the compiler.

For your case it means:

• Create a file .syntastic_cpp_config under sources (assuming that's where your code is and sources is at a same depth level in the directory hierarchy as libs).

• Put the following lines in it:

  -Ilibs/dir1

  -Ilibs/dir2

  -Ilibs/dir2/dir3

• Note the the flags are 1 per line.

• This way you don't have to have all the include directories in your .vimrc.

You can have a different file to hold this custom configuration per project, specified by the .vimrc global variable g:syntastic_cpp_config_file, eg

let g:syntastic_cpp_config_file = '.my_custom_include_file_for_syntastic'

Syntastic will check each source directory and upwards until it finds this file and then use it for producing its output.

See the Syntastic wiki page, Old link for more details.