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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 Niels Sejersen

    Hmm, I think you can make use of how Keil arranges/places variables in memory. They are not arranged in order of declaration, they are arranged alphabetically.

    This is a painfully bad idea. Not only is it completely unportable, and needlessly so, it will even break with the Keil tool-chain if you tell C51 to keep varables in order via the ORDER directive.

    Write a program to generate the .c and .h files. Then it could be used with other tools.

Reply
  • 0 in reply to Niels Sejersen

    Hmm, I think you can make use of how Keil arranges/places variables in memory. They are not arranged in order of declaration, they are arranged alphabetically.

    This is a painfully bad idea. Not only is it completely unportable, and needlessly so, it will even break with the Keil tool-chain if you tell C51 to keep varables in order via the ORDER directive.

    Write a program to generate the .c and .h files. Then it could be used with other tools.

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