GCC seems to have a problem dereferenzing pointers. Example code:
1 | #define MAX_A 4
|
2 | #define MAX_AS 5
|
3 | |
4 | typedef char str16[16]; |
5 | |
6 | typedef struct stc_a* ptr_stc_a; |
7 | |
8 | typedef struct stc_a { |
9 | U8 number_a; |
10 | str16 text_a; |
11 | } t_a, *ptr_t_a; |
12 | |
13 | typedef t_a arr_t_a[MAX_AS]; |
14 | typedef arr_t_a* ptr_arr_t_a; |
15 | |
16 | |
17 | typedef struct stc_b* ptr_stc_b; |
18 | |
19 | typedef struct stc_b { |
20 | U8 number_b; |
21 | ptr_arr_t_a arr_a; |
22 | } t_b, *ptr_t_b; |
23 | |
24 | |
25 | #define PTR_ARR_A (ptr_arr_t_a)&array_a
|
26 | |
27 | const arr_t_a array_a = { |
28 | {0,"ZERO\0"}, |
29 | {1,"ONE\0"}, |
30 | {2,"TWO\0"}, |
31 | {3,"THREE\0"}, |
32 | {4,"FOUR\0"} |
33 | };
|
34 | |
35 | t_b b = { 0, PTR_ARR_A }; |
36 | |
37 | ptr_t_b ptr_b; |
38 | |
39 | |
40 | #define CR PUTCH0('\r')
|
41 | |
42 | void test_stc(void) |
43 | {
|
44 | U8 i; |
45 | |
46 | ptr_b = (ptr_t_b)&b; |
47 | |
48 | CR; |
49 | my_prints("TEST\r"); |
50 | my_printf("ptr_b = %lp\r",ptr_b); |
51 | my_printf("&b = %lp\r",&b); |
52 | my_printf("&array_a = %lp\r",&array_a); |
53 | |
54 | my_printf("sizeof(t_a) = 0x%02X\r",sizeof(t_a)); |
55 | my_printf("sizeof(arr_t_a) = 0x%02X\r",sizeof(arr_t_a)); |
56 | my_printf("sizeof(t_b) = 0x%02X\r",sizeof(t_b)); |
57 | |
58 | CR; |
59 | my_prints("Addresses dereferencing ptr_b \r"); |
60 | my_printf("ptr_b->number_b = %lp\r",&(ptr_b->number_b)); |
61 | for(i=0;i<MAX_AS;i++) |
62 | {
|
63 | my_printf("ptr_b->arr_a[%d] = %lp\r",i,&(ptr_b->arr_a[i])); |
64 | }
|
65 | |
66 | CR; |
67 | my_prints("Addresses const array_a in FLASH \r"); |
68 | my_printf("&array_a = %lp\r",&(array_a)); |
69 | for(i=0;i<MAX_AS;i++) |
70 | {
|
71 | my_printf("&array_a[%d] = %lp\r",i,&(array_a[i])); |
72 | }
|
73 | |
74 | }
|
Debug output (UART)
1 | MCU : Spansion FM3 MB9BF516N ARM Cortex-M3 |
2 | Firmware : v00.02 |
3 | CM3 CMSIS : v04.30 |
4 | GNUC : v05.02.01 (46712) |
5 | Compiled : Feb 29 2016 @ 13:28:05 |
6 | |
7 | TEST |
8 | ptr_b = 0x1fff8038 |
9 | &b = 0x1fff8038 |
10 | &array_a = 0xba5c |
11 | sizeof(t_a) = 0x11 |
12 | sizeof(arr_t_a) = 0x55 |
13 | sizeof(t_b) = 0x08 |
14 | |
15 | Addresses dereferencing ptr_b |
16 | ptr_b->number_b = 0x1fff8038 |
17 | ptr_b->arr_a[0] = 0xba5c |
18 | ptr_b->arr_a[1] = 0xbab1 |
19 | ptr_b->arr_a[2] = 0xbb06 |
20 | ptr_b->arr_a[3] = 0xbb5b |
21 | ptr_b->arr_a[4] = 0xbbb0 |
22 | |
23 | Addresses const array_a in FLASH |
24 | &array_a = 0xba5c |
25 | &array_a[0] = 0xba5c |
26 | &array_a[1] = 0xba6d |
27 | &array_a[2] = 0xba7e |
28 | &array_a[3] = 0xba8f |
29 | &array_a[4] = 0xbaa0 |
As you can see accessing the array via "ptr_b->arr_a[x]" the pointer is incremented with sizeof(arr_t_a) instead sizeof(t_a)... Ideas/Workarounds???
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