Re: master 888ff3755d4 1/3: New function internal--c-header-file-path

[Eli Zaretskii <eliz@gnu.org>]

Stefan,

Thanks for adding this function.  However, the method it uses to find
the include directories is incorrect and unportable.  On most systems
it will produce the default "/usr/include", which is most probably
wrong.

The way to ask GCC to show the list of directories where it looks for
header files is like this:

   (call-process "gcc" nil BUFFER nil "-v" "-E" "-")

and then look in BUFFER for text that begins with "#include <...>
search starts here:" and ends with "End of search list."  What's
in-between is the list of include directories, one directory per line,
which GCC searches for header file, in the order it searches them.