[Bug middle-end/79297] New: [7 Regression] ICE (segfault) in main_block_label

[doko at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79297

            Bug ID: 79297
           Summary: [7 Regression] ICE (segfault) in main_block_label
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: doko at gcc dot gnu.org
  Target Milestone: ---

seen with trunk 20170129

$ cat share.ii
struct a {
  a() {
    goto b;
    if (0)
    b:;
  }
} c;
(exp)doko@gb:/scratch/packages/tmp/yosys-0.7$ g++ -std=c++11 -c share.ii 
share.ii: In constructor 'a::a()':
share.ii:2:3: internal compiler error: Segmentation fault
   a() {
   ^
0xb1317f crash_signal
        ../../src/gcc/toplev.c:333
0xb3c743 main_block_label
        ../../src/gcc/tree-cfg.c:1381
0xb3cc3d cleanup_dead_labels()
        ../../src/gcc/tree-cfg.c:1564
0xb477f1 build_gimple_cfg
        ../../src/gcc/tree-cfg.c:238
0xb477f1 execute_build_cfg
        ../../src/gcc/tree-cfg.c:397
0xb477f1 execute
        ../../src/gcc/tree-cfg.c:433
Please submit a full bug report,
with preprocessed source if appropriate.