[fpc-pascal] Platform Dependent Integer Types

[African Wild Dog]

2017-04-06 18:50 GMT-03:00 Mattias Gaertner <nc-gaertnma at netcologne.de>:

> Why do you think that Delphi's longint has 64bits anywhere?
> Delphi's NativeInt is 32 or 64bit depending on platform.
>
>
http://docwiki.embarcadero.com/RADStudio/Tokyo/en/Internal_Data_Formats_(Delphi)#Platform-Independent_Signed_Integer_Types
.
As Marco have pointed out, in Windows the Delphi's LongInt type is always
32-bits. On other platforms is platform dependent.


>
> > The documentation says "every platform has a ”native” integer size,
> > depending on whether the platform is 8-bit, 16-bit, 32-bit or 64-bit.
> e.g.
> > On AVR this is 8-bit. ", but it is not clear about which integer types
> are
> > "natives".
>
> Most of FPC's integer types defined via IFDFEs. See
> fpc/rtl/inc/systemh.inc
> You can use Lazarus' Find Declaration on any type and see the
> definition.
> For example:
>
> {$ifdef CPU64}
>   SizeInt = Int64;
>   SizeUInt = QWord;
>   PtrInt = Int64;
>   PtrUInt = QWord;
>   ValSInt = int64;
>   ValUInt = qword;
>   CodePointer = Pointer;
>   CodePtrInt = PtrInt;
>   CodePtrUInt = PtrUInt;
> {$endif CPU64}
>
> {$ifdef CPU32}
>   SizeInt = Longint;
>   SizeUInt = DWord;
>   PtrInt = Longint;
>   PtrUInt = DWord;
>   ValSInt = Longint;
>   ValUInt = Cardinal;
>   CodePointer = Pointer;
>   CodePtrInt = PtrInt;
>   CodePtrUInt = PtrUInt;
> {$endif CPU32}
>
>
>   { NativeInt and NativeUInt are Delphi compatibility types. Even though
> Delphi
>     has IntPtr and UIntPtr, the Delphi documentation for NativeInt states
> that
>     'The size of NativeInt is equivalent to the size of the pointer on the
>     current platform'. Because of the misleading names, these types
> shouldn't be
>     used in the FPC RTL. Note that on i8086 their size changes between
> 16-bit
>     and 32-bit according to the memory model, so they're not really a
> 'native
>     int' type there at all. }
>

Still not clear for me. Are NativeInt and NativeUInt provided for Delphi
compatibility, right? So, if i need an integer type which depends on
platform/fpc compilation mode, which one should i use?
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