[Bug middle-end/59119] New: Segfault in -fisolate-erroneous-paths pass

[uweigand at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59119

            Bug ID: 59119
           Summary: Segfault in -fisolate-erroneous-paths pass
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: uweigand at gcc dot gnu.org

Building the following test case (reduced from Python 2.7.5) with -O2 -g:

extern void *memmove (void *, const void *, __SIZE_TYPE__);
extern void *memset (void *, int, __SIZE_TYPE__);

typedef struct {
    long n_prefix;
    long n_spadding;
} NumberFieldWidths;

void
fill_number(char *buf, const NumberFieldWidths *spec)
{
    if (spec->n_prefix) {
        memmove(buf,
                (char *) 0,
                spec->n_prefix * sizeof(char));
        buf += spec->n_prefix;
    }
    if (spec->n_spadding) {
        memset(buf, 0, spec->n_spadding);
        buf += spec->n_spadding;
    }
}

crashes the compiler with:

formatter_string.i: In function ‘fill_number’:
formatter_string.i:11:1: internal compiler error: Segmentation fault
 fill_number(char *buf, const NumberFieldWidths *spec)
 ^
0x1064f147 crash_signal
        /home/uweigand/src/gcc/gcc/toplev.c:334
0x1090806c ptrofftype_p
        /home/uweigand/src/gcc/gcc/tree.h:4463
0x1090806c build2_stat(tree_code, tree_node*, tree_node*, tree_node*)
        /home/uweigand/src/gcc/gcc/tree.c:4151
0x1022c0db gimple_assign_rhs_to_tree(gimple_statement_d*)
        /home/uweigand/src/gcc/gcc/cfgexpand.c:103
0x10861e67 insert_debug_temp_for_var_def(gimple_stmt_iterator_d*, tree_node*)
        /home/uweigand/src/gcc/gcc/tree-ssa.c:442
0x10862397 insert_debug_temps_for_defs(gimple_stmt_iterator_d*)
        /home/uweigand/src/gcc/gcc/tree-ssa.c:549
0x103ff49b gsi_remove(gimple_stmt_iterator_d*, bool)
        /home/uweigand/src/gcc/gcc/gimple-iterator.c:563
0x10ba8083 insert_trap_and_remove_trailing_statements
        /home/uweigand/src/gcc/gcc/gimple-ssa-isolate-paths.c:110
0x10ba8a47 gimple_ssa_isolate_erroneous_paths
        /home/uweigand/src/gcc/gcc/gimple-ssa-isolate-paths.c:305
0x10ba8a47 execute
        /home/uweigand/src/gcc/gcc/gimple-ssa-isolate-paths.c:370