correct check for -rdynamic

[Dan McMahill]

Anyone have a correct check to see if the compiler needs/accepts 
-rdynamic or maybe -Wl,--export-dynamic?


We were using a test like:

AC_MSG_CHECKING([If the compiler accepts -rdynamic])
old_LDFLAGS="$LDFLAGS"
LDFLAGS="$LDFLAGS -rdynamic"
AC_LINK_IFELSE([int main(){}],
        [AC_MSG_RESULT([yes])],
        [LDFLAGS="$old_LDFLAGS"
        AC_MSG_RESULT([no])
        ])


unfortunately, while this seems to work with gcc, it does not work with 
SunPRO.  Here are some examples of how this test might play out.


> cc -rdynamic -o foo foo.c
cc: Warning: illegal option -dynamic
> echo $?
0

so configure thinks rdynamic is ok however, foo is not ok:

> file foo
foo:            ELF 32-bit MSB relocatable SPARC32PLUS Version 1, V8+ 
Required
> ls -l foo
-rw-r--r--   1 yyyyy yyyyy     429116 Oct 16 22:12 foo

note that foo is not an executible, it is a relocatable.

Without  -rdynamic, things are ok:

> cc  -o foo foo.c
> file foo
foo:            ELF 32-bit MSB executable SPARC32PLUS Version 1, V8+ 
Required, dynamically linked, not stripped
> ls -l foo
-rwxr-xr-x   1 yyyyy yyyyy       6984 Oct 16 22:12 foo


> cc -V
cc: Sun C 5.8 2005/10/13
usage: cc [ options] files.  Use 'cc -flags' for details


I actually don't think you need any sort of -rdynamic or 
-Wl,--export-dynamic with SunPRO, but I really don't know about some of 
the other compilers out there (MipsPRO for example).

Suggestions?

Thanks
-Dan