Re: "Run tests with low max_cmd_len" on MSYS/MSVC

[Peter Rosin]

Den 2009-01-21 22:54, skrev Ralf Wildenhues:
> Hi Peter,
>
> * Peter Rosin wrote on Wed, Jan 21, 2009 at 02:26:36AM CET:
> > This patch together with [1] and [2] will make "Run tests with
> > low max_cmd_len" on MSYS/MSVC behave the same as the individual
> > tests.
> >
> > The patch fixes a couple more of the /abs/path issues already
> > fixed in [1] and [2]. However, I fear that these hunks may be
> > more controversial, as they touch code that affects other
> > platforms as well.
>
> Well, for non-w32 systems the patch is pretty obviously ok, as
> func_to_host_path doesn't do much there, and not slowly.  :-)
>
> For Cygwin and MinGW, it will likely make things much slower, since
> this will cause lots of forks.

Indeed.

>                                 From a correctness perspective, the
> patch looks good to go, though.

For MinGW yes, for Wine this is probably not needed (Wine allows
opening both posix and win32 files in its CreateFile implementation),
and for Cygwin it is probably at least theoretically wrong (but it
might work, I don't know how liberal open is in Cygwin...)

As soon as you try to use Cygwin to launch native Win32 programs you
are on thin ice. So, libtool on Cygwin should IMHO assume that the
MinGW toolchain is a Cygwin hosted MinGW targeting toolchain. If the
MinGW toolchain is like that - and I believe that both the soon
historic "gcc -mno-cygwin" as well as the new "i686-pc-mingw32-gcc"
toolchains are - then libtool has no business tampering with the
posix paths using "cygpath -w" in these cases.

Maybe there should be a second (optional) arg to func_to_host_path
that indicates why you want to convert the path? Or perhaps a new
func_to_toolchain_path that only converts the path if the toolchain
isn't really for $host? I.e. is instead running in some kind of
emulator or in some other subsystem or otherwise has a different
notion of paths (like MSVC on MSYS).

But when to use func_to_toolchain_path would be system specific as
it is only needed on MSYS when MSYS for one reason or another fails
to convert the path (an /absolute/path is stored in a command file
or appears after some prefix on the command line that MSYS doesn't
recognize, e.g. -out:/absolute/path). On Cygwin it would be needed
for all /absolute/paths passed to the toolchain. On Wine it wouldn't
be wrong to do as on Cygwin, but it would perhaps be overkill to
always convert as Wine handles posix paths in CreateFile.

Cheers,
Peter