[Bug libstdc++/55041] prettyprinting/shared_ptr & cxx11 fails on some platforms

["redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55041

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-10-28 12:54:01 UTC ---
I think the reason this doesn't show up everywhere is due to a problem with
older versions of GDB.  Using GDB 7.3.50.20110722-16.fc16 I get this in the
test logs:

48362.gdb:5: Error in sourced command file:^M
No symbol "t1" in current context.^M
skipping: 48362.gdb:5: Error in sourced command file:^M
skipping: No symbol "t1" in current context.^M
UNSUPPORTED: libstdc++-prettyprinters/48362.cc

and I've had the same problem running gdb myself, with gdb saying "No symbol x
in current context" for all local variables, when they clearly do exist!

I also see GDB 7.3 completely confused about the type of std::string:

Temporary breakpoint 1, main () at d.cc:6
6         std::string s1 = "string 1";
(gdb) n
7         std::string s2 = "string 2";
(gdb) p s1
$1 = {i = {1431655765, -1077586603}, x = -0.16666666666666666}
(gdb) ptype s1
type = const union {
    int4 i[2];
    double x;
}

Huh?!

Using GDB from the git mirror or upgrading to rawhide's 7.5.0.20120926-25.fc18
makes the problem go away and now I see the FAILs when running
libstdc++-prettyprinters.exp (which I'm fixing now)

This only happens for code built with trunk, so there seems to be some problem
with trunk and GDB 7.3 - any ideas?