[EMAIL PROTECTED] wrote: > On Mon, Oct 10, 2005 at 02:11:04PM +0200, Florian Klaempfl wrote: > >>[EMAIL PROTECTED] wrote: >> >> >>>Hi. >>> >>>After a few hours with gdb was isolated errors and strangeness in compiler >>>at work with variants: >>> >>>Example: >>> >>>function c(const vv: variant): variant; >>>begin >>> result := vv; >>>end; >>> >>>function b(vv: variant): variant; >>>begin >>> result := vv; >>>end; >>> >>>function a(var vv: variant): variant; >>>begin >>> result := vv; >>>end; >>> >>>procedure start; >>>var >>> v, v1: Variant; >>>begin >>> v := VarArrayCreate([0, 0], varVariant); >>> >>> a(v); >>> //if variant result of a() isn't assigned, fpc_finalize() at end of a(v) >>> //destroys temporary result. But when start() ends fpc_finalize() tryes >>> //to destroy it again >>> >>> b(v); >>> //if b() is called then variant param is copied but not whole (deeply), >>> vv.varray >>> //points to the same place as v.array. At end of b(v) is pointer >>> //vv.array destroyed by fpc_decref() and then v.array points to the >>> //destroyed memory >>> >>> c(v); >>> //At the start of func c() is v copied to the vv deeply but i think >>> //that behaviour of "var" and "const" calling should be the same (by >>> //reference) not vy value like c() >>>end; >>> >>>I try to understand compiler code and repair it, but this is "very long >>>distance race". But like I see the responses to my previous reports >>>(absolutely no interest), this will be fastest solution :(. Really here >>>isn't anybody who understand to compiler code and help me with repair? >>>Or is anywhere another e-mail list or another comunication channel where >>>i can talk about this problem? >>> >>>Petr >>> >> >>The var arrays problems are known, see also >>http://www.freepascal.org/bugs/showrec.php3?ID=3830 >> >>It requires some design changes though that's why it isn't fixed yet. The >>problem is that the compiler handles variants as ref. counted types when >>passing >>them as parameters etc. However, this is wrong behaviour as soon as a variant >>contains an array. > > Thanks for explanation. Yesterday i looked at compiler code and fpc > internals documentation. I must recognize that fixing this is beyond my > strength. Is somebody working on it? I can help with debugging. > Vararray problem stopped my work -- porting big information system to fpc. > In Rtl/fcl i can repair or fill missing, but here i'am helpless. > For that reason i hurry on fixing this.
If you implement a fpc_copy procedure which copies rtti'ed types properly in rtl/inc/rtti.inc, we're already a huge step forward :) _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
