Re: CL Parameter ends up fulla crud. -- MIDRANGE-L


On 17/01/2006, at 8:41 AM, Larry Bolhuis wrote:

Called PGM has three parms 10, 8 and 8 bytes all character.

Calling pgm passes in 10, 8 and 1 byte parms, also all character.

Everything comes across but parm 3 has 7 bytes of crud after byte 1,
which is correct.


Yes, it's correct that there is crud in the final 7 bytes.

This ain't supposed ta happen, correct?

Yes, it is supposed to happen. You are passing one byte to a programexpecting 8 bytes. Unless told otherwise the receiving program will see8 bytes of storage at the address passed by the caller.

We'd fix the one byte parm to 8 bytes but there are hundreds of thesein the system and
the crud just appears randomly.

The crud will appear random because it's whatever happens to be instorage after the 1 byte value.


Either:
        o change the caller to pass the correct 8 bytes, or
        o change the receiver to expect 1 byte, or
        o change both caller and callee to pass a length parameter.

If you are calling a module or procedure then you could use operationaldescriptors to determine the length passed in the callee. This willrequire a prototyped call with OPDESC specified in RPG, a #pragmadescriptor in C, and 'linkage procedure using all described' in COBOL.CLLE always passes operational descriptors.

i5, V5R3, late 2005 CUMes and Groups.


Immaterial--this is a programming defect.

Regards,
Simon Coulter.
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