[fpc-devel] TypeInfo RTTI / possible inconsistency

[Martin Frb]

I was looking at TypeInfo (based on 3.2.2rc)

line 632  unit TypInfo
>             tkMethod:
>               (MethodKind : TMethodKind;
>                ParamCount : Byte;
>                ParamList : array[0..1023] of Char
>              {in reality ParamList is a array[1..ParamCount] of:
>                   record
>                     Flags : TParamFlags;
>                     ParamName : ShortString;
>                     TypeName : ShortString;
>                   end;
>               followed by
>                   ResultType : ShortString     // for mkFunction, 
> mkClassFunction only
>                   ResultTypeRef : PPTypeInfo;  // for mkFunction, 
> mkClassFunction only
>                   CC : TCallConv;
>                   ParamTypeRefs : array[1..ParamCount] of PPTypeInfo;}
>               );

To find out about alignment (for any target which needs alignment), I 
looked through other code:

fpc_3.2.2\source\tests\webtbs\tw12038.pp
    line 194    procedure DisplayDetails(Informations : TPropInfo; const 
expectedresult: ansistring);
appears to access the data (except for the ParamTypeRefs array)
The testcase does not seem to make any adjustments for alignment.

fpc_3.2.2\source\packages\rtl-objpas\src\inc\rtti.pp
    line 3341    TRttiMethodType.GetParameters
also appears to access the same typeinfo.
It makes alignments in 3 different places
    ptr := AlignTParamFlags(ptr);                // foreach   Flags : 
TParamFlags;   in the ParamList
    ptr := AlignToPtr(PByte(ptr) + ptr^ + SizeOf(Byte));    // ResultTypeRef
    paramtypes := PPPTypeInfo(AlignTypeData(ptr));       // ParamTypeRefs

Which is correct?
Or do they access different structures?


----------------------
A few other notes:
FPC_REQUIRES_PROPER_ALIGNMENT
does not seem to be listed on 
https://www.freepascal.org/docs-html/prog/progap7.html


TypInfo line 1461
in Procedure GetPropInfos(TypeInfo : PTypeInfo;PropList : PPropList);
TP:=aligntoptr(PPropInfo(aligntoptr((Pointer(@TD^.UnitName)+Length(TD^.UnitName)+1))));
Why call aligntoptr twice?
The TypeCast in between does not change the alignment. (all the math is 
done within the innermost call)