https://gcc.gnu.org/bugzilla/show_bug.cgi?id=31186
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |INVALID
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The remaining environment variables apply only when preprocessing the
particular language indicated. Each specifies a list of directories to be
searched as if specified with -isystem, but after any paths given with -isystem
options on the command line.
If a standard system include directory, or a directory specified with -isystem,
is also specified with -I, the -I option is ignored. The directory is still
searched but as a system directory at its normal position in the system include
chain. This is to ensure that GCC’s procedure to fix buggy system headers and
the ordering for the #include_next directive are not inadvertently changed. If
you really need to change the search order for system directories, use the
-nostdinc and/or -isystem options. See System Headers.
This part specifically:
If you really need to change the search order for system directories, use the
-nostdinc and/or -isystem options.
