tree-cfg.c (verify_gimple_in_cfg): Verify no non-label stmts with the exception…

tree-cfg.c (verify_gimple_in_cfg): Verify no non-label stmts with the exception of debug begin stmt markers appear...

	* tree-cfg.c (verify_gimple_in_cfg): Verify no non-label stmts
	with the exception of debug begin stmt markers appear before
	labels.

From-SVN: r255611

gcc/ChangeLog

 2017-12-13  Jakub Jelinek  <jakub@redhat.com>
 
+	* tree-cfg.c (verify_gimple_in_cfg): Verify no non-label stmts
+	with the exception of debug begin stmt markers appear before
+	labels.
+
 	PR bootstrap/83396
 	* final.c (rest_of_handle_final): Call variable_tracking_main only
 	if !flag_var_tracking.

gcc/tree-cfg.c

@@ -5380,6 +5380,7 @@ verify_gimple_in_cfg (struct function *fn, bool verify_nothrow)
 	  err |= err2;
 	}
 
+      bool label_allowed = true;
       for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
 	{
 	  gimple *stmt = gsi_stmt (gsi);
@@ -5396,6 +5397,19 @@ verify_gimple_in_cfg (struct function *fn, bool verify_nothrow)
 	      err2 = true;
 	    }
 
+	  /* Labels may be preceded only by debug markers, not debug bind
+	     or source bind or any other statements.  */
+	  if (gimple_code (stmt) == GIMPLE_LABEL)
+	    {
+	      if (!label_allowed)
+		{
+		  error ("gimple label in the middle of a basic block");
+		  err2 = true;
+		}
+	    }
+	  else if (!gimple_debug_begin_stmt_p (stmt))
+	    label_allowed = false;
+
 	  err2 |= verify_gimple_stmt (stmt);
 	  err2 |= verify_location (&blocks, gimple_location (stmt));