Fix GCC7 warnings about switch-case fallthroughs

GCC7 with -Wextra warns about switch-case blocks which fallthrough with
"this statement may fall through [-Werror=implicit-fallthrough=]". This
can be fixed by adding "special" comments: "/* fallthrough */".

See https://gcc.gnu.org/gcc-7/changes.html

Change-Id: Iba0be791dbdd86984489b2d9a0592bb59828da1e
Signed-off-by: Freddie Chopin <freddie.chopin@gmail.com>
Reviewed-on: http://openocd.zylin.com/4174
Tested-by: jenkins

src/flash/mflash.c

@@ -259,11 +259,11 @@ static int mg_dsk_wait(mg_io_type_wait wait_local, uint32_t time_var)
 				case mg_io_wait_rdy:
 					if (status & mg_io_rbit_status_ready)
 						return ERROR_OK;
-
+					/* fallthrough */
 				case mg_io_wait_drq:
 					if (status & mg_io_rbit_status_data_req)
 						return ERROR_OK;
-
+					/* fallthrough */
 				default:
 					break;
 			}

src/flash/nand/mx3.c

@@ -281,6 +281,7 @@ static int imx31_command(struct nand_device *nand, uint8_t command)
 			 * offset == one half of page size
 			 */
 			in_sram_address = MX3_NF_MAIN_BUFFER0 + (nand->page_size >> 1);
+			break;
 		default:
 			in_sram_address = MX3_NF_MAIN_BUFFER0;
 	}

src/flash/nor/kinetis.c

@@ -2126,6 +2126,7 @@ static int kinetis_probe_chip(struct kinetis_chip *k_chip)
 			case KINETIS_SDID_FAMILYID_K6X | KINETIS_SDID_SUBFAMID_KX1:	/* errata 7534 - should be K63 */
 			case KINETIS_SDID_FAMILYID_K6X | KINETIS_SDID_SUBFAMID_KX2:	/* errata 7534 - should be K64 */
 				subfamid += 2; /* errata 7534 fix */
+				/* fallthrough */
 			case KINETIS_SDID_FAMILYID_K6X | KINETIS_SDID_SUBFAMID_KX3:
 				/* K63FN1M0 */
 			case KINETIS_SDID_FAMILYID_K6X | KINETIS_SDID_SUBFAMID_KX4:

src/helper/command.c

@@ -1456,8 +1456,8 @@ COMMAND_HELPER(handle_command_parse_bool, bool *out, const char *label)
 				LOG_ERROR("%s: argument '%s' is not valid", CMD_NAME, in);
 				return ERROR_COMMAND_SYNTAX_ERROR;
 			}
-			/* fall through */
 		}
+			/* fallthrough */
 		case 0:
 			LOG_INFO("%s is %s", label, *out ? "enabled" : "disabled");
 			break;

src/jtag/drivers/ftdi.c

@@ -855,6 +855,7 @@ COMMAND_HANDLER(ftdi_handle_set_signal_command)
 			ftdi_set_signal(sig, *CMD_ARGV[1]);
 			break;
 		}
+		/* fallthrough */
 	default:
 		LOG_ERROR("unknown signal level '%s', use 0, 1 or z", CMD_ARGV[1]);
 		return ERROR_COMMAND_SYNTAX_ERROR;

src/jtag/drivers/kitprog.c

@@ -657,6 +657,7 @@ static int kitprog_swd_switch_seq(enum swd_special_seq seq)
 				LOG_DEBUG("JTAG to SWD not supported");
 				/* Fall through to fix target reset issue */
 			}
+			/* fallthrough */
 		case LINE_RESET:
 			LOG_DEBUG("SWD line reset");
 			if (kitprog_swd_seq(SEQUENCE_LINE_RESET) != ERROR_OK)

src/svf/svf.c

@@ -661,11 +661,13 @@ static int svf_read_command_from_file(FILE *fd)
 				if (svf_getline(&svf_read_line, &svf_read_line_size, svf_fd) <= 0)
 					return ERROR_FAIL;
 				i = -1;
+				/* fallthrough */
 			case '\r':
 				slash = 0;
 				/* Don't save '\r' and '\n' if no data is parsed */
 				if (!cmd_pos)
 					break;
+				/* fallthrough */
 			default:
 				/* The parsing code currently expects a space
 				 * before parentheses -- "TDI (123)".  Also a

src/target/arm_adi_v5.c

@@ -346,8 +346,10 @@ static int mem_ap_write(struct adiv5_ap *ap, const uint8_t *buffer, uint32_t siz
 			case 4:
 				outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
 				outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
+				/* fallthrough */
 			case 2:
 				outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
+				/* fallthrough */
 			case 1:
 				outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
 			}
@@ -509,8 +511,10 @@ static int mem_ap_read(struct adiv5_ap *ap, uint8_t *buffer, uint32_t size, uint
 			case 4:
 				*buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
 				*buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
+				/* fallthrough */
 			case 2:
 				*buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
+				/* fallthrough */
 			case 1:
 				*buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
 			}
@@ -519,8 +523,10 @@ static int mem_ap_read(struct adiv5_ap *ap, uint8_t *buffer, uint32_t size, uint
 			case 4:
 				*buffer++ = *read_ptr >> 8 * (address++ & 3);
 				*buffer++ = *read_ptr >> 8 * (address++ & 3);
+				/* fallthrough */
 			case 2:
 				*buffer++ = *read_ptr >> 8 * (address++ & 3);
+				/* fallthrough */
 			case 1:
 				*buffer++ = *read_ptr >> 8 * (address++ & 3);
 			}

src/target/arm_disassembler.c

@@ -3299,6 +3299,7 @@ static int t2ev_data_immed(uint32_t opcode, uint32_t address,
 		case 0x10:
 		case 0x12:
 			is_signed = true;
+			/* fallthrough */
 		case 0x18:
 		case 0x1a:
 			/* signed/unsigned saturated add */

src/target/target.c

@@ -3684,7 +3684,7 @@ COMMAND_HANDLER(handle_bp_command)
 				addr = 0;
 				return handle_bp_command_set(CMD_CTX, addr, asid, length, hw);
 			}
-
+			/* fallthrough */
 		case 4:
 			hw = BKPT_HARD;
 			COMMAND_PARSE_ADDRESS(CMD_ARGV[0], addr);