[Bug middle-end/50295] New: [4.6 Regression] ICE (segfault) in expand_debug_expr at cfgexpand.c:2380

[doko at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50295

             Bug #: 50295
           Summary: [4.6 Regression] ICE (segfault) in expand_debug_expr
                    at cfgexpand.c:2380
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: doko@gcc.gnu.org


Created attachment 25197
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25197
preprocessed source

seen with 4.6 20110903 on i686-linux-gnu, with -Os and -O2, works with -O1 and
-O0, works with -Os and -O2 when omitting -g.

The ICE is triggered by the nsrefcnt WyciwygChannelChild::AddRef line, omitting
this line doesn't show the ICE.

$ gcc -c -g -O2 -std=gnu++0x  WyciwygChannelChild.ii 
/home/chrisccoulson/src/firefox/firefox-7.0~b4+build2+nobinonly/build-tree/mozilla/netwerk/protocol/wyciwyg/WyciwygChannelChild.cpp:
In member function 'virtual nsresult
mozilla::net::WyciwygChannelChild::CloseCacheEntry(nsresult)':
/home/chrisccoulson/src/firefox/firefox-7.0~b4+build2+nobinonly/build-tree/mozilla/netwerk/protocol/wyciwyg/WyciwygChannelChild.cpp:605:1:
internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.

Program received signal SIGSEGV, Segmentation fault.
0x0820cec8 in expand_debug_expr (exp=0xf28c5d50) at
../../gcc-4_6-branch/gcc/cfgexpand.c:2380
2380      enum machine_mode mode = TYPE_MODE (TREE_TYPE (exp));
(gdb) bt
#0  0x0820cec8 in expand_debug_expr (exp=0xf28c5d50) at
../../gcc-4_6-branch/gcc/cfgexpand.c:2380
#1  0x08210208 in expand_debug_locations () at
../../gcc-4_6-branch/gcc/cfgexpand.c:3316
#2  gimple_expand_cfg () at ../../gcc-4_6-branch/gcc/cfgexpand.c:4112
#3  0x08366147 in execute_one_pass (pass=0x8aa5780) at
../../gcc-4_6-branch/gcc/passes.c:1556
#4  0x083663f5 in execute_pass_list (pass=0x8aa5780) at
../../gcc-4_6-branch/gcc/passes.c:1611
#5  0x08434ac5 in tree_rest_of_compilation (fndecl=0xf3447d80) at
../../gcc-4_6-branch/gcc/tree-optimize.c:422
#6  0x085711f9 in cgraph_expand_function (node=0xf3342000) at
../../gcc-4_6-branch/gcc/cgraphunit.c:1576
#7  0x08572f85 in cgraph_expand_all_functions () at
../../gcc-4_6-branch/gcc/cgraphunit.c:1635
#8  cgraph_optimize () at ../../gcc-4_6-branch/gcc/cgraphunit.c:1899
#9  0x08573405 in cgraph_finalize_compilation_unit () at
../../gcc-4_6-branch/gcc/cgraphunit.c:1096
#10 0x0812682b in cp_write_global_declarations () at
../../gcc-4_6-branch/gcc/cp/decl2.c:4000
#11 0x083f800d in compile_file () at ../../gcc-4_6-branch/gcc/toplev.c:591
#12 do_compile () at ../../gcc-4_6-branch/gcc/toplev.c:1900
#13 toplev_main (argc=16, argv=0xffffd6c4) at
../../gcc-4_6-branch/gcc/toplev.c:1963
#14 0x080d018b in main (argc=16, argv=0xffffd6c4) at
../../gcc-4_6-branch/gcc/main.c:36