[Mingw-users] S_IRWXG, S_IRWXO undefined when building gcc 4.9.2 with mingwrt 3.20

[David G. <DGr...@am...>]

I had previously successfully built gcc 4.9.2 ; I am now trying it again after
having upgraded to the mingwrt 3.21 and I am having problems.

I get through a large part of the build, but shortly after generating 13,000 
lines  in the log file, the xgcc compiler chokes on this file:

gcc-4.9.2/libgfortran/io/unix.c

at line 1133.

The offending line is

mode_mask = umask (S_IXUSR | S_IRWXG | S_IRWXO);

The compiler has no problems with S_IXUSR but cannot find definitions for
S_IRWXG and S_IRWXO. 

S_IXUSR is defined in  sys/stat.h and I would expect  theother two to be 
defined there as well, but they are not.

A bit of searching finds both of the missing items are defined  in a directory
fairly deeply buried in the msys directory structure, but the definitions there 
look very unixish and won't do for use in the MinGW sys/stat.h.

A search for the missing definitions in the source code for the previous
version of mingwrt turns up nothing. 

The offending line of code is protected inside an #ifdef HAVE_UMASK.

This leads me to believe that something in mingwrt 3.21 is causing the
gcc 4.9.2 build to be misconfigured and it is causing HAVE_UMASK to
be defined  when it should not be, so that the build is compiling code that
should not be compiled for Windows. I should file a ticket for this,
but I would like to be able to propose a patch when I do that.

Does anybody have any idea  what could be causing this? The next 
step is to compare the present and previous versions of mingwrt,
but I don't want to waste time reinventing wheels that someone else
already knows about.