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Merged
tridge merged 2 commits into from
Mar 23, 2026
Merged

Inline coding of 0-length messages #39

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fbe5819
add level of indirection to <msg>_encode and <msg>_decode
tpwrules Jul 20, 2024
436bc22
inline coding of 0-length messages
tpwrules Jul 20, 2024
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8 changes: 4 additions & 4 deletions templates/msg.c.em
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Original file line number Diff line number Diff line change
Expand Up @@ -11,14 +11,14 @@
#include <test_helpers.h>
#endif

uint32_t @(msg_underscored_name)_encode(@(msg_c_type)* msg, uint8_t* buffer
uint32_t _@(msg_underscored_name)_encode(@(msg_c_type)* msg, uint8_t* buffer
#if CANARD_ENABLE_TAO_OPTION
, bool tao
#endif
) {
uint32_t bit_ofs = 0;
memset(buffer, 0, @(msg_define_name.upper())_MAX_SIZE);
_@(msg_underscored_name)_encode(buffer, &bit_ofs, msg,
__@(msg_underscored_name)_encode(buffer, &bit_ofs, msg,
#if CANARD_ENABLE_TAO_OPTION
tao
#else
Expand All @@ -31,14 +31,14 @@ uint32_t @(msg_underscored_name)_encode(@(msg_c_type)* msg, uint8_t* buffer
/*
return true if the decode is invalid
*/
bool @(msg_underscored_name)_decode(const CanardRxTransfer* transfer, @(msg_c_type)* msg) {
bool _@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, @(msg_c_type)* msg) {
#if CANARD_ENABLE_TAO_OPTION
if (transfer->tao && (transfer->payload_len > @(msg_define_name.upper())_MAX_SIZE)) {
return true; /* invalid payload length */
}
#endif
uint32_t bit_ofs = 0;
if (_@(msg_underscored_name)_decode(transfer, &bit_ofs, msg,
if (__@(msg_underscored_name)_decode(transfer, &bit_ofs, msg,
#if CANARD_ENABLE_TAO_OPTION
transfer->tao
#else
Expand Down
55 changes: 44 additions & 11 deletions templates/msg.h.em
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Original file line number Diff line number Diff line change
Expand Up @@ -69,18 +69,51 @@ extern "C"
{
#endif

uint32_t @(msg_underscored_name)_encode(@(msg_c_type)* msg, uint8_t* buffer
uint32_t _@(msg_underscored_name)_encode(@(msg_c_type)* msg, uint8_t* buffer
#if CANARD_ENABLE_TAO_OPTION
, bool tao
#endif
);
bool @(msg_underscored_name)_decode(const CanardRxTransfer* transfer, @(msg_c_type)* msg);
bool _@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, @(msg_c_type)* msg);

static inline uint32_t @(msg_underscored_name)_encode(@(msg_c_type)* msg, uint8_t* buffer
#if CANARD_ENABLE_TAO_OPTION
, bool tao
#endif
) {
@[if msg_max_bitlen == 0]
(void)msg;
(void)buffer;
#if CANARD_ENABLE_TAO_OPTION
(void)tao;
#endif

return 0; // 0-length message encodes to 0 bytes
@[else]
return _@(msg_underscored_name)_encode(msg, buffer
#if CANARD_ENABLE_TAO_OPTION
, tao
#endif
);
@[end if]
}

static inline bool @(msg_underscored_name)_decode(const CanardRxTransfer* transfer, @(msg_c_type)* msg) {
@[if msg_max_bitlen == 0]
(void)msg;

// all transports accurately convey a payload length of 0 bytes so any payload is an error
return transfer->payload_len != 0;
@[else]
return _@(msg_underscored_name)_decode(transfer, msg);
@[end if]
}

#if defined(CANARD_DSDLC_INTERNAL)
@{indent = 0}@{ind = ' '*indent}@
static inline void _@(msg_underscored_name)_encode(uint8_t* buffer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao);
static inline bool _@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao);
void _@(msg_underscored_name)_encode(uint8_t* buffer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao) {
static inline void __@(msg_underscored_name)_encode(uint8_t* buffer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao);
static inline bool __@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao);
void __@(msg_underscored_name)_encode(uint8_t* buffer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao) {
@{indent += 1}@{ind = ' '*indent}@
@(ind)(void)buffer;
@(ind)(void)bit_ofs;
Expand All @@ -101,7 +134,7 @@ void _@(msg_underscored_name)_encode(uint8_t* buffer, uint32_t* bit_ofs, @(msg_c
@{indent += 1}@{ind = ' '*indent}@
@[ end if]@
@[ if field.type.category == field.type.CATEGORY_COMPOUND]@
@(ind)_@(underscored_name(field.type))_encode(buffer, bit_ofs, &msg->@(field.name), @('tao' if (field == msg_fields[-1] or msg_union) else 'false'));
@(ind)__@(underscored_name(field.type))_encode(buffer, bit_ofs, &msg->@(field.name), @('tao' if (field == msg_fields[-1] or msg_union) else 'false'));
@[ elif field.type.category == field.type.CATEGORY_PRIMITIVE]@
@[ if field.type.kind == field.type.KIND_FLOAT and field.type.bitlen == 16]@
@(ind){
Expand Down Expand Up @@ -144,7 +177,7 @@ void _@(msg_underscored_name)_encode(uint8_t* buffer, uint32_t* bit_ofs, @(msg_c
@[ end if]@
@(ind)*bit_ofs += @(field.type.value_type.bitlen);
@[ elif field.type.value_type.category == field.type.value_type.CATEGORY_COMPOUND]@
@(ind)_@(underscored_name(field.type.value_type))_encode(buffer, bit_ofs, &msg->@(field_get_data(field))[i], @[if field == msg_fields[-1] and field.type.value_type.get_min_bitlen() < 8]tao && i==msg->@(field.name).len@[else]false@[end if]);
@(ind)__@(underscored_name(field.type.value_type))_encode(buffer, bit_ofs, &msg->@(field_get_data(field))[i], @[if field == msg_fields[-1] and field.type.value_type.get_min_bitlen() < 8]tao && i==msg->@(field.name).len@[else]false@[end if]);
@[ end if]@
@{indent -= 1}@{ind = ' '*indent}@
@(ind)}
Expand All @@ -167,7 +200,7 @@ void _@(msg_underscored_name)_encode(uint8_t* buffer, uint32_t* bit_ofs, @(msg_c
/*
decode @(msg_underscored_name), return true on failure, false on success
*/
bool _@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao) {
bool __@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, uint32_t* bit_ofs, @(msg_c_type)* msg, bool tao) {
@{indent += 1}@{ind = ' '*indent}@
@(ind)(void)transfer;
@(ind)(void)bit_ofs;
Expand All @@ -194,7 +227,7 @@ bool _@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, uint32_t*
@{indent += 1}@{ind = ' '*indent}@
@[ end if]@
@[ if field.type.category == field.type.CATEGORY_COMPOUND]@
@(ind)if (_@(underscored_name(field.type))_decode(transfer, bit_ofs, &msg->@(field.name), @('tao' if (field == msg_fields[-1] or msg_union) else 'false'))) {return true;}
@(ind)if (__@(underscored_name(field.type))_decode(transfer, bit_ofs, &msg->@(field.name), @('tao' if (field == msg_fields[-1] or msg_union) else 'false'))) {return true;}
@[ elif field.type.category == field.type.CATEGORY_PRIMITIVE]@
@[ if field.type.kind == field.type.KIND_FLOAT and field.type.bitlen == 16]@
@(ind){
Expand Down Expand Up @@ -235,7 +268,7 @@ bool _@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, uint32_t*
@(ind)uint32_t max_bits = (transfer->payload_len*8)-7; // TAO elements must be >= 8 bits
@(ind)while (max_bits > *bit_ofs) {
@{indent += 1}@{ind = ' '*indent}@
@(ind)if (!max_len-- || _@(underscored_name(field.type.value_type))_decode(transfer, bit_ofs, &msg->@(field_get_data(field))[msg->@(field.name).len], @[if field == msg_fields[-1] and field.type.value_type.get_min_bitlen() < 8]tao && i==msg->@(field.name).len@[else]false@[end if])) {return true;}
@(ind)if (!max_len-- || __@(underscored_name(field.type.value_type))_decode(transfer, bit_ofs, &msg->@(field_get_data(field))[msg->@(field.name).len], @[if field == msg_fields[-1] and field.type.value_type.get_min_bitlen() < 8]tao && i==msg->@(field.name).len@[else]false@[end if])) {return true;}
@(ind)msg->@(field.name).len++;
@{indent -= 1}@{ind = ' '*indent}@
@(ind)}
Expand Down Expand Up @@ -269,7 +302,7 @@ bool _@(msg_underscored_name)_decode(const CanardRxTransfer* transfer, uint32_t*
@[ end if]@
@(ind)*bit_ofs += @(field.type.value_type.bitlen);
@[ elif field.type.value_type.category == field.type.value_type.CATEGORY_COMPOUND]@
@(ind)if (_@(underscored_name(field.type.value_type))_decode(transfer, bit_ofs, &msg->@(field_get_data(field))[i], @[if field == msg_fields[-1] and field.type.value_type.get_min_bitlen() < 8]tao && i==msg->@(field.name).len@[else]false@[end if])) {return true;}
@(ind)if (__@(underscored_name(field.type.value_type))_decode(transfer, bit_ofs, &msg->@(field_get_data(field))[i], @[if field == msg_fields[-1] and field.type.value_type.get_min_bitlen() < 8]tao && i==msg->@(field.name).len@[else]false@[end if])) {return true;}
@[ end if]@
@{indent -= 1}@{ind = ' '*indent}@
@(ind)}
Expand Down
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