Some low-hanging -Wunreachable-code fruits.

- after croak/die/exit (or return), break (or return!) are pointless
  (break is not a terminator/separator, it's a promise of a jump)
- after goto, another goto (!) is pointless
- in some cases (usually function ends) introduce explicit NOT_REACHED
  to make the noreturn nature clearer (do not do this everywhere, though,
  since that would mean adding NOT_REACHED after every croak)
- for the added NOT_REACHED also add /* NOTREACHED */ since
  NOT_REACHED is for gcc (and VC), while the comment is for linters
- declaring variables in switch blocks is just too fragile:
  it kind of works for narrowing the scope (which is nice),
  but breaks the moment there are initializations for the variables
  (they will be skipped!); in some easy cases simply hoist the declarations
  out of the block and move them earlier

There are still a few places left.

1 files changed, 3 insertions, 4 deletions

diff --git a/pp_ctl.c b/pp_ctl.c
index ab729b0334..8957a8ceed 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -1357,9 +1357,8 @@ Perl_block_gimme(pTHX)
 	return G_ARRAY;
     default:
 	Perl_croak(aTHX_ "panic: bad gimme: %d\n", cxstack[cxix].blk_gimme);
-	assert(0); /* NOTREACHED */
-	return 0;
     }
+    NOT_REACHED; /* NOTREACHED */
 }
 
 I32
@@ -4336,8 +4335,8 @@ PP(pp_leaveeval)
 			SvPVX_const(namesv),
                         SvUTF8(namesv) ? -(I32)SvCUR(namesv) : (I32)SvCUR(namesv),
 			G_DISCARD);
-	retop = Perl_die(aTHX_ "%"SVf" did not return a true value",
-			       SVfARG(namesv));
+	Perl_die(aTHX_ "%"SVf" did not return a true value", SVfARG(namesv));
+        NOT_REACHED; /* NOTREACHED */
 	/* die_unwind() did LEAVE, or we won't be here */
     }
     else {