Re: Wierd sparc sunos4 intermittant SEGV during bootstrap in libgcc2.a

[Jim Wilson <wilson at cygnus dot com>]

I haven't tried any FSF gcc sources on SunOS4 systems here.

However, the Cygnus source tree has been failing on SunOS4 systems since our
last merge from the FSF gcc source tree.  I tracked the problem down to a
problem with the Sun C library strncmp function reading past the end of
strings.  Now that gcc uses mmap, and we've got mmap allocating disjoint
memory regions, we end up with many places where mapped memory ends.  Formerly,
there was only one place where mapped memory ended, at the end of the heap.
When you have lots of places where memory ends, there is a much higher change
that a string will end up against a place where memory ends, and if that
happens, then you can get a segfault.  These failures I saw were repeatable
though.

Disabling use of mmap is one of the first things I'd try if I had problems
with SunOS4.

Jim