Tool/software: TI C/C++ Compiler
I am using C2000 compiler 18.1.7.LTS and have the following (complex) aggregate initialization:
struct can_rcv_buffer_element can_buf_tx_motor_stat = {0};
the struct definition is:
struct can_rcv_buffer_sdu
{
uint32_t can_id;
uint16_t data[8];
uint16_t len;
bool locked;
};
{
uint32_t can_id;
uint16_t data[8];
uint16_t len;
bool locked;
};
struct can_rcv_buffer_element
{
struct can_rcv_buffer_sdu sdu[2]; /* double-buffer */
uint16_t recent_page;
};
{
struct can_rcv_buffer_sdu sdu[2]; /* double-buffer */
uint16_t recent_page;
};
Acc. to dis2000 it creates the following .cinit entry:
DATA Section .cinit (Little Endian), 0x26 words at 0x00000000
...
0000000a fffe .word 0xfffe /* length = 2 */
0000000b 0040 .word 0x0040 /* address */
0000000c 0000 .word 0x0000 /* address */
0000000d 0000 .word 0x0000 /* value */
0000000e 0000 .word 0x0000 /* value */
This makes only limited sense. The first element in the struct is 32bit, however
in my understanding, the initialization should follow C standard clauses:
10 If an object that has automatic storage duration is not initialized explicitly, its value is indeterminate.
If an object that has static storage duration is not initialized explicitly, then:
— if it has pointer type, it is initialized to a null pointer;
— if it has arithmetic type, it is initialized to (positive or unsigned) zero;
— if it is an aggregate, every member is initialized (recursively) according to these rules;
— if it is a union, the first named member is initialized (recursively) according to theserules
21 If there are fewer initializers in a brace-enclosed list than there are elements or members of an aggregate, or fewer characters in a string literal used to initialize an array of knownsize than there are elements in the array, the remainder of the aggregate shall beinitialized implicitly the same as objects that have static storage duration.
With a complete explicit initialization, compiler behaves as it should:
struct can_rcv_buffer_element can_buf_tx_motor_stat = {
.sdu[0].can_id = 0,
.sdu[0].data = {1,2,3,4,5,6,7,8},
.sdu[0].len = 0,
.sdu[0].locked = 0,
.sdu[1].can_id = 0,
.sdu[1].data = {1,2,3,4,5,6,7,8},
.sdu[1].len = 0,
.sdu[1].locked = 0,
.recent_page = 0,
};-->
0000000a ffe7 .word 0xffe7 /* length = 25 */
0000000b 0040 .word 0x0040
0000000c 0000 .word 0x0000
0000000d 0000 .word 0x0000
0000000e 0000 .word 0x0000
0000000f 0001 .word 0x0001
00000010 0002 .word 0x0002
00000011 0003 .word 0x0003
00000012 0004 .word 0x0004
00000013 0005 .word 0x0005
00000014 0006 .word 0x0006
00000015 0007 .word 0x0007
00000016 0008 .word 0x0008
00000017 0000 .word 0x0000
00000018 0000 .word 0x0000
00000019 0000 .word 0x0000
0000001a 0000 .word 0x0000
0000001b 0001 .word 0x0001
0000001c 0002 .word 0x0002
0000001d 0003 .word 0x0003
0000001e 0004 .word 0x0004
0000001f 0005 .word 0x0005
00000020 0006 .word 0x0006
00000021 0007 .word 0x0007
00000022 0008 .word 0x0008
00000023 0000 .word 0x0000
00000024 0000 .word 0x0000
00000025 0000 .word 0x0000
