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

["dominiq at lps dot ens.fr" <gcc-bugzilla at gcc dot gnu dot org>]

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

           Summary: [4.6 Regression] gcc.dg/plugin/plugindir*.c gives ICEs
                    on powerpc-apple-darwin9
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dominiq@lps.ens.fr
                CC: dj@redhat.com, ian@airs.com, joseph@codesourcery.com,
                    iains@gcc.gnu.org
              Host: powerpc-apple-darwin9
            Target: powerpc-apple-darwin9
             Build: powerpc-apple-darwin9


Between revisions 166379 and 166752 on my logs the following failures in the
test suite appeared on powerpc-apple-darwin9 with both -m32 and -m64:

FAIL: gcc.dg/plugin/plugindir1.c (internal compiler error)
FAIL: gcc.dg/plugin/plugindir1.c (test for excess errors)
FAIL: gcc.dg/plugin/plugindir2.c (internal compiler error)
FAIL: gcc.dg/plugin/plugindir2.c (test for excess errors)
FAIL: gcc.dg/plugin/plugindir3.c (internal compiler error)
FAIL: gcc.dg/plugin/plugindir3.c (test for excess errors)
FAIL: gcc.dg/plugin/plugindir4.c (internal compiler error)
FAIL: gcc.dg/plugin/plugindir4.c (test for excess errors)

Reduced range from regress: revision 166543 works, revision 166589 fails, see:
http://gcc.gnu.org/ml/gcc-testresults/2010-11/msg00831.html
http://gcc.gnu.org/ml/gcc-testresults/2010-11/msg00875.html
Without better knowledge, revisions 166544, 166552, 16653, 166555, 166565, and
166570 could be candidates (no guarantee about an exhaustive list!-).

These failures are due to ICEs during the compilation

[karma] f90/bug% /opt/gcc/gcc4.6w/bin/gcc -c -fplugin=foo
/opt/gcc/gcc-4.6-work/gcc/testsuite/gcc.dg/plugin/plugindir1.c
[address=fffffffc pc=94afe928]
cc1: internal compiler error: Segmentation Fault

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
#3  0x00515888 in handle_common_deferred_options () at
../../gcc-4.6-work/gcc/opts-global.c:385
#4  0x005e3844 in toplev_main (argc=3, argv=0xffffffff) at
../../gcc-4.6-work/gcc/toplev.c:1923
#5  0x00002560 in start ()

This PR seems different from pr43759.