../../i86pc/os/trap.c:610:4: error: this statement may fall through [-Werror=implicit-fallthrough=]
    (void) die(type, rp, addr, cpuid);
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../i86pc/os/trap.c:614:2: note: here
  case T_PGFLT:  /* system page fault */
  ^~~~

../../i86pc/os/trap.c: In function 'dump_ttrace':
../../i86pc/os/trap.c:2161:10: error: this statement may fall through [-Werror=implicit-fallthrough=]
      sys = &sysent[rec->ttr_sysnum];
      ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
../../i86pc/os/trap.c:2168:5: note: here
     case TT_SYSC:
     ^~~~

../../i86pc/boot/boot_console.c:507:3: error: this statement may fall through [-Werror=implicit-fallthrough=]
   ++p;
   ^~~
../../i86pc/boot/boot_console.c:508:2: note: here
  default:
  ^~~~~~~
../../i86pc/boot/boot_console.c:525:3: error: this statement may fall through [-Werror=implicit-fallthrough=]
   ++p;
   ^~~
../../i86pc/boot/boot_console.c:526:2: note: here
  default:
  ^~~~~~~

../../common/disp/cmt.c: In function 'pg_cmt_lineage_validate':
../../common/disp/cmt.c:1887:6: error: this statement may fall through [-Werror=implicit-fallthrough=]
   if (((pghw_t *)pg)->pghw_hw == PGHW_CHIP) {
      ^
../../common/disp/cmt.c:1894:2: note: here
  case CMT_LINEAGE_NON_PROMOTABLE:
  ^~~~

../../common/os/lgrp.c:3726:6: error: this statement may fall through [-Werror=implicit-fallthrough=]
   if (lgrp != lgrp_root) {
      ^
../../common/os/lgrp.c:3735:2: note: here
  case LGRP_MEM_POLICY_RANDOM:
  ^~~~
../../common/os/lgrp.c:3785:8: error: this statement may fall through [-Werror=implicit-fallthrough=]
   stat = LGRP_NUM_RANDOM_PROC;
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~
../../common/os/lgrp.c:3788:2: note: here
  case LGRP_MEM_POLICY_RANDOM_PSET:
  ^~~~

cc1: all warnings being treated as errors