Using __attribute__((packed)) instead of pragmas

Author: cmaglie

cores/arduino/USB/CDC.cpp

@@ -37,15 +37,14 @@ extern USBDevice_SAMD21G18x usbd;
 
 #define CDC_LINESTATE_READY		(CDC_LINESTATE_RTS | CDC_LINESTATE_DTR)
 
-typedef struct {
+typedef struct __attribute__((packed)) {
 	uint32_t dwDTERate;
 	uint8_t bCharFormat;
 	uint8_t bParityType;
 	uint8_t bDataBits;
 	uint8_t lineState;
 } LineInfo;
 
-_Pragma("pack(1)")
 static volatile LineInfo _usbLineInfo = {
 	115200, // dWDTERate
 	0x00,   // bCharFormat
@@ -55,7 +54,6 @@ static volatile LineInfo _usbLineInfo = {
 };
 
 static volatile int32_t breakValue = -1;
-_Pragma("pack()")
 
 // CDC
 #define CDC_ACM_INTERFACE  pluggedInterface              // CDC ACM

cores/arduino/USB/USBCore.cpp

@@ -156,9 +156,7 @@ uint32_t USBDeviceClass::sendConfiguration(uint32_t maxlen)
 	_dry_run = true;
 	uint8_t interfaces = SendInterfaces(&total);
 
-	_Pragma("pack(1)")
 	ConfigDescriptor config = D_CONFIG((uint16_t)(total + sizeof(ConfigDescriptor)), interfaces);
-	_Pragma("pack()")
 
 	//	Now send them
 	_dry_run = false;

cores/arduino/USB/USBCore.h

@@ -107,10 +107,8 @@
 #define MSC_SUBCLASS_SCSI						0x06
 #define MSC_PROTOCOL_BULK_ONLY					0x50
 
-_Pragma("pack(1)")
-
 //	Device
-typedef struct {
+typedef struct __attribute__((packed)) {
 	uint8_t len;				// 18
 	uint8_t dtype;				// 1 USB_DEVICE_DESCRIPTOR_TYPE
 	uint16_t usbVersion;		// 0x200
@@ -128,7 +126,7 @@ typedef struct {
 } DeviceDescriptor;
 
 //	Config
-typedef struct {
+typedef struct __attribute__((packed)) {
 	uint8_t	len;			// 9
 	uint8_t	dtype;			// 2
 	uint16_t clen;			// total length
@@ -142,8 +140,7 @@ typedef struct {
 //	String
 
 //	Interface
-typedef struct
-{
+typedef struct __attribute__((packed)) {
 	uint8_t len;		// 9
 	uint8_t dtype;		// 4
 	uint8_t number;
@@ -156,8 +153,7 @@ typedef struct
 } InterfaceDescriptor;
 
 //	Endpoint
-typedef struct
-{
+typedef struct __attribute__((packed)) {
 	uint8_t len;		// 7
 	uint8_t dtype;		// 5
 	uint8_t addr;
@@ -168,8 +164,7 @@ typedef struct
 
 // Interface Association Descriptor
 // Used to bind 2 interfaces together in CDC compostite device
-typedef struct
-{
+typedef struct __attribute__((packed)) {
 	uint8_t len;				// 8
 	uint8_t dtype;				// 11
 	uint8_t firstInterface;
@@ -180,15 +175,12 @@ typedef struct
 	uint8_t iInterface;
 } IADDescriptor;
 
-typedef struct
-{
+typedef struct __attribute__((packed)) {
 	InterfaceDescriptor			msc;
 	EndpointDescriptor			in;
 	EndpointDescriptor			out;
 } MSCDescriptor;
 
-_Pragma("pack()")
-
 #define D_DEVICE(_class,_subClass,_proto,_packetSize0,_vid,_pid,_version,_im,_ip,_is,_configs) \
 	{ 18, 1, 0x200, _class,_subClass,_proto,_packetSize0,_vid,_pid,_version,_im,_ip,_is,_configs }
 /* Table 9-8. Standard Device Descriptor