Memory Access Violation

[gelarimer]

I have been troubleshooting a memory access
violation and found the following line of code
in a function that initializes the OPENFILENAME
structure:

OFN%LpStrFileTitle = LOC(gszFileTitle//"*.txt"C)

Where gszFileTitle is a Global variable.

code should have been:

OFN%LpStrFileTitle = NULL

LOC(gszFileTitle//"*.txt"C) does not produce a
compiler error, so I assume that a temporary memory
location is created to hold the string
gszFileTitle//"*.txt"//ACHAR(0). However, after the
function returns I assume the address becomes invalid.

If the paragraph above is correct it would explain
the memory access violation.

Any comments would be appreciated.

[Steven_L_Intel1]

Your understanding is correct. You are allowed to take LOC(expression), but the expression is on the routine local stack and the address is no longer valid after the routine exits.

[gelarimer]

Thanks Steve. The program ran for a couple of years before the memory access violations started to occur.Apparently a minor change in another routinecausedthe fn. GetOpenFileName(OFN) to overwrite a critical memory location. That location was the invalid address retained by OFN%LpStrFileTitle. The OFN structure is alsoGlobal.