Description of problem:
some software using the signal.h header can't be compiled
on Itanium systems. Assume a file a.c containing only
the #include <signal.h> , compile it:
gcc -c a.c
then you see the following error message:
In file included from /usr/include/signal.h:341,
                  from a.c:1:
/usr/include/bits/sigstack.h:57: redefinition of `struct sigaltstack'

Another problem also only on ia64 has to do with the enum
in sigstack.h line 34+. SS_ONSTACK and SS_DISABLE are already
defined in /usr/include/asm/signal.h . sigstack.h may be included
later so after preprocessing the compiler finally sees:
enum
{
  1 = 1,

  2

};
leading to barfing. in my opinion the enum for ss_flags is
superfluous.

Version-Release number of selected component (if applicable):
glibc-2.3.2-69 through glibc-2.3.2-77

How reproducible:


Steps to Reproduce:
1. echo '#include <signal.h>' > a.c
2. gcc -c a.c
3.
    
Actual results:
Compiler error message


Expected results:
a.o created

Additional info:
does not happen on Opteron or x86 with the same software versions