From 19db887a6c57ad42b17b24256a5b2cf9125e898b Mon Sep 17 00:00:00 2001
From: Thomas Martens <thomas@defaultschuldiger.de>
Date: Mon, 14 Aug 2017 22:52:21 +0200
Subject: [PATCH] Added a define "FALLTHROUGH" to suppress 'this statement may
 fallthrough' messages Since avr-gcc version 7 the flag -Wimplicit-fallthrough
 is set, so that a missing "break;" inside a switch-case statement will throw
 an error in the compiling process. The missing breaks are replaced by the
 FALLTHROUGH define and no errors occours. FALLTHROUGH is simply an
 "__attribute__((fallthrough));" - if it is supported by the compiler.

---
 examples/board_timer_64led/timer_64led.c |  2 ++
 simavr/sim/avr_adc.c                     |  2 ++
 simavr/sim/sim_avr.h                     | 10 ++++++++++
 simavr/sim/sim_core.c                    |  1 +
 4 files changed, 15 insertions(+)

diff --git a/examples/board_timer_64led/timer_64led.c b/examples/board_timer_64led/timer_64led.c
index 5e6fe3f..c5f4e26 100644
--- a/examples/board_timer_64led/timer_64led.c
+++ b/examples/board_timer_64led/timer_64led.c
@@ -104,8 +104,10 @@ void displayCB(void)		/* function called whenever redisplay needed */
 			switch (i) {
 				case 3:
 					dy += 3.0f * pixsize;
+					FALLTHROUGH
 				case 6:
 					dy += 3.0f * pixsize;
+					FALLTHROUGH
 				case 0:
 					dx += 1.0f * pixsize;
 					glVertex2f(dx + size, dy + size); glVertex2f(dx, dy + size); glVertex2f(dx, dy); glVertex2f(dx + size, dy);
diff --git a/simavr/sim/avr_adc.c b/simavr/sim/avr_adc.c
index 4565b89..b563cba 100644
--- a/simavr/sim/avr_adc.c
+++ b/simavr/sim/avr_adc.c
@@ -140,8 +140,10 @@ avr_adc_read_h(
 	switch (p->read_status) {
 		case 0:
 			avr_adc_read_l(avr, p->r_adcl, param);
+			FALLTHROUGH
 		case 1:
 			p->read_status = 2;
+			FALLTHROUGH
 		default:
 			return avr_core_watch_read(avr, addr);
 	}
diff --git a/simavr/sim/sim_avr.h b/simavr/sim/sim_avr.h
index 035e41e..aedffb2 100644
--- a/simavr/sim/sim_avr.h
+++ b/simavr/sim/sim_avr.h
@@ -26,6 +26,16 @@
 extern "C" {
 #endif
 
+#ifndef __has_attribute
+	#define __has_attribute(x) 0
+#endif
+
+#if __has_attribute(fallthrough)
+	#define FALLTHROUGH __attribute__((fallthrough));
+#else
+	#define FALLTHROUGH
+#endif
+
 #include "sim_irq.h"
 #include "sim_interrupts.h"
 #include "sim_cmds.h"
diff --git a/simavr/sim/sim_core.c b/simavr/sim/sim_core.c
index 8650c85..f3b163d 100644
--- a/simavr/sim/sim_core.c
+++ b/simavr/sim/sim_core.c
@@ -976,6 +976,7 @@ run_one_again:
 				case 0x9518: 	// RETI -- Return from Interrupt -- 1001 0101 0001 1000
 					avr_sreg_set(avr, S_I, 1);
 					avr_interrupt_reti(avr);
+					FALLTHROUGH
 				case 0x9508: {	// RET -- Return -- 1001 0101 0000 1000
 					new_pc = _avr_pop_addr(avr);
 					cycle += 1 + avr->address_size;
-- 
2.39.5