Re: [MinGW] Set NATIVE_SYSTEM_HEADER_DIR relative to configured prefix

["Ranjit Mathew" <rmathew at gmail dot com>]

On 6/3/06, Mark Mitchell <mark@codesourcery.com> wrote:
> Ranjit Mathew wrote:
> > Hi,
> >
> >   After Mark's patch in:
> >
> >   http://gcc.gnu.org/ml/gcc-patches/2005-08/msg00122.html
>
> Ranjit --
>
> Sorry, I got these messages out of order.  Now, I understand what you
> were asking about.

So did you mean STANDARD_INCLUDE_DIR or SYSTEM_INCLUDE_DIR
in that patch? The configury seems to set SYSTEM_INCLUDE_DIR to
NATIVE_SYSTEM_HEADER_DIR for native builds, so your assertion in
t-mingw32 seemed to be a tautology to me.


> > So I propose that MinGW's NATIVE_SYSTEM_HEADER_DIR be
> > set relative to its configured prefix as shown by the
> > attached patch.
>
> That doesn't make sense to me.  There's no guarantee that the MinGW
> headers are in the same location as the compiler; if your MinGW headers
> are in /mingw/include, you can still install the compiler in /usr/local.
>  On most systems, the system header directory is a constant; if it's
> not, for MinGW, then I think you need a new configure option.

Unlike UNIX, MinGW does not have a standard include folder where
headers are *always* supposed to be. "/mingw/include" is more like
a convention and possibly proclaimed from being forced to spell out
such a thing by the rest of GCC (Danny will correct me if I'm wrong).

One can get the following packages from MinGW:

 1. GCC
 2. binutils
 3. mingw-runtime
 4. w32api

extract them into a folder of one's choice and expect to have a
working compiler system. The all-in-one MinGW installer does a
similar thing. MSYS asks for your MinGW installation path and adds
an /etc/fstab entry to make "/mingw" map to that location.

My point is that expecting standard headers in the "include" sub-folder
of the compiler installation root seems to be the norm in MinGW-land
rather than the exception and in my humble opinion, a very desirable
property for toolchain relocation.

When I create a crossed-native compiler, creating "/mingw" is not
always possible or desirable and I have to use --with-sys-root. Even
then the headers have to be extracted into the "mingw" sub-folder of
the sys-root folder, which is weird when you pack it all up and install
it on a Windows box.


> (Of course, if users are free to put the MinGW headers wherever they
> like, then if you ship compiler binaries to someone, you can't know
> where they may have put the headers.  So, I would expect people would
> need to use -isystem in that situation.)

Exactly. If people don't want to put headers inside the "include"
sub-folder of the GCC installation for MinGW for some reason, they
can always use -isystem.

Thanks,
Ranjit.

--
Ranjit Mathew      Email: rmathew AT gmail DOT com

Bangalore, INDIA.    Web: http://rmathew.com/