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const struct/unon initialization proble.

M D

Hi,

with the following sample code...

typedef __packed struct
{
        uint8_t field_1;
        uint8_t field_2;
        uint8_t field_3;
        uint8_t field_4;
} T_Sub;

typedef __packed struct
{
        T_Sub   Sub;
        uint8_t field_1;
        uint8_t field_2;
        uint8_t field_3;
        uint8_t field_4;
} T_Data;

typedef __packed union
{
        T_Data  content;
        uint8_t buffer[sizeof(T_Data)];
} T_Union;

const T_Union C_Union = { {1,2,3,4}, 1, 2, 3, 4, 5};

// The following (no union, just strcut) has the same problem
/*
typedef __packed struct
{
        T_Data  content;
} T_Struct;

const T_Struct C_Struct = { {1,2,3,4}, 1, 2, 3, 4, 5};
*/


I get:

error:  #146: too many initializer values

I'm using uVision4.
The same code works on other compilers. I'm obviously missing something big but I can't figure what...

  • 0

    sorry... the correct code is

    typedef __packed struct
{
        uint8_t field_1;
        uint8_t field_2;
        uint8_t field_3;
        uint8_t field_4;
} T_Sub;

typedef __packed struct
{
        T_Sub   Sub;
        uint8_t field_1;
        uint8_t field_2;
        uint8_t field_3;
        uint8_t field_4;
} T_Data;

typedef __packed union
{
        T_Data  content;
        uint8_t buffer[sizeof(T_Data)];
} T_Union;

const T_Union C_Union = { {1,2,3,4}, 1, 2, 3, 4};

    and I get the same error (the 5th initializer was just a test to check if I get the same error)

  • 0 in reply to M D

    try:

    const T_Union C_Union = {{ {1,2,3,4}, 1, 2, 3, 4}};

  • 0 in reply to M D

    Ummm you may need to consider WHAT structure you are initializing a union can be either structure, so it's possible it could be assuming it's the array portion of the union to which there are too many for a single element ( 4 by viewing your code ). I would suggest you use type T_Data for your constant and not the union. Otherwise you have an ambiguity in which type of structure you are initializing.

    Further more I strong urge you to use MACRO's to form any such structure constants because of one typo can create unexpected results very easily. Save all the drudgery for the PREPROCESSOR I always say.

    Stephen

  • 0 in reply to stephen phillips

    @Stefan HartwigPosted
    Yes, it works... kinda fussy :-)

    @stephen phillipsPosted
    According to many C bibles, the first field of the union is the one that is assigned., there shoud no be ambiguity...
    My code does use macros but I wroted a simple example to exlcude eventual macro errors...

    Thank you

  • 0 in reply to M D

    Yes, it works... kinda fussy :-)
    It isn't fussy at all. Strip down what you are doing:

    typedef __packed struct
{
        uint8_t field_1;
        uint8_t field_2;
        uint8_t field_3;
        uint8_t field_4;
} T_Sub;

const T_Sub T_Sub_example = {1, 2, 3, 4};

typedef __packed struct
{
        T_Sub Sub;
        uint8_t field_1;
        uint8_t field_2;
        uint8_t field_3;
        uint8_t field_4;
} T_Data;

const T_Data T_Data_example =
        {
                /* T_Sub_example */ {1, 2, 3, 4},
                /* field_1 to field_4 */ 5, 6, 7, 8
        };

typedef __packed union
{
        T_Data  content;
        uint8_t buffer[sizeof(T_Data)];
} T_Union;

const T_Union T_Union_example =
        {
        /* T_Data_example */
                {
                /* T_Sub_example */ {1, 2, 3, 4},
                /* field_1 to field_4 */ 5, 6, 7, 8
                }
        /* empty since the array "buffer" is not initialized */
        };