[fpc-pascal]Strange Segfault...

Matt Emson memsom at interalpha.co.uk
Mon Jul 14 11:23:30 CEST 2003

> Yes and no. Why is it so bad to write a function in that way ? It could
> of course be written two different ways, but I'd rather this way where I
> modify the string passed to the function.
> Explain it to me :) (I'm the only one that works on this project of
> ~30,000 LOC, so I don't see any problem)

Turbo Pascal and Delphi 1 had a type called 'String'. This was limited to
255 chars, size of 256 chars, and position 0 holds the strings length.
Delphi 2+ has a type called shortstring that behaves in exactly the same way
as the old style string.

Delphi 2+ altered the string type to be a pointer to a chunk of memory, and
added a whole load of compiler magic to make strings automatically grow and
shrink, added reference counting and 'copy of change' functionality (the
last two to aid in not having to copy a string until someone alters it.)
This is where your problem lies.

Because FPC mimics Delphi string functionality, basically you'll end up with
similar results.

You'd be much better off Returning a value, and thereby avoiding the
potential for big allocation/deallocations. That or use shortstrings.


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