[Bug c/46902] [4.6 Regression] gcc.dg/plugin/plugindir*.c gives ICEs on powerpc-apple-darwin9

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46902

--- Comment #2 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2010-12-13 18:20:16 UTC ---
On Sun, 12 Dec 2010, dominiq at lps dot ens.fr wrote:

> The backtrace is
> 
> Program received signal EXC_BAD_ACCESS, Could not access memory.
> Reason: KERN_INVALID_ADDRESS at address: 0xfffffffc
> 0x94afe928 in strlen ()
> (gdb) bt
> #0  0x94afe928 in strlen ()
> #1  0x008b6414 in concat (first=0xffffffff <Address 0xffffffff out of bounds>)
> at ../../gcc-4.6-work/libiberty/concat.c:76
> #2  0x0051e660 in add_new_plugin (plugin_name=0xbfffdac2 "foo") at
> ../../gcc-4.6-work/gcc/plugin.c:157

Which of the arguments in the call to concat is invalid?  How did that 
argument get its value?