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Placing size of array at start of array

Richard Collett

Hi all,
I am working with the TI TUSB3200, trying to modify their example code for our own USB device. USB requires many tables which start with a length byte. I would like to use the sizeof operator to calculate this for me, as shown here:

byte code rictest[] =
{
	sizeof(rictest),
	1,
	2
};
This gives the error 
warning C198: sizeof returns 0
, so plainly the compiler only does a single pass through the code, and does not know the array size until it has finished parsing the entire array definition. :(

Is there any other way to achieve this? I presume it would be possible with some sort of pre-processor macro to count the number of elements manually before defining the aray...

Parents
  • 0 in reply to Jon Ward

    Jon suggested "If you are creating the VID and PID tables for USB, you can create structs for each of these and then you may use the sizeof operator to initialize the VID or PID structure."

    Thanks for the suggestion Jon, but it is the mainly the configuration descriptor (which is huge, about 280 bytes), which I am concerned about.

    I am slowly coming to the conclusion that I will have to write a seperate program to dynamically generate a .c file and matching .h file.

Reply
  • 0 in reply to Jon Ward

    Jon suggested "If you are creating the VID and PID tables for USB, you can create structs for each of these and then you may use the sizeof operator to initialize the VID or PID structure."

    Thanks for the suggestion Jon, but it is the mainly the configuration descriptor (which is huge, about 280 bytes), which I am concerned about.

    I am slowly coming to the conclusion that I will have to write a seperate program to dynamically generate a .c file and matching .h file.

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