[fpc-devel] windows shlobj SIGDN longint

[J. Gareth "Kit" Moreton]

Ah, if you mean that SIGDN is defined as a DWord in its C headers but as 
a LongInt in FPC, then I think it's due to backwards compatibility back 
when Turbo Pascal and Delphi didn't have an unsigned 32-bit integer type 
(LongWord), and so such a hexadecimal constant would default to LongInt.

Gareth aka. Kit

On 24/06/2026 23:51, Mattias Gaertner via fpc-devel wrote:
>
>
> On 6/24/26 22:54, J. Gareth "Kit" Moreton via fpc-devel wrote:
>> Hmmm, that's a little bit difficult.  What happens if you define the 
>> constants as, say, "SIGDN_FILESYSPATH = longint($80058000);"?
>
> Then it would compile.
>
> But it seems the C code uses DWord, so why should FPC use longint?
>
> Mattias
>
>>
>> Gareth aka. Kit
>>
>> On 24/06/2026 21:44, Mattias Gaertner via fpc-devel wrote:
>>>
>>>
>>> On 6/24/26 22:35, J. Gareth "Kit" Moreton via fpc-devel wrote:
>>>> I think it's deliberately designed that way so such codes are 
>>>> negative numbers in signed 32-bit.
>>>
>>> I spotted it because code fails to compile with a range check error.
>>>
>>> Windows docs says these constants are from an enumeration.
>>>
>>> Mattias
>>>
>>>
>>>> Gareth aka. Kit
>>>>
>>>> On 24/06/2026 20:51, Mattias Gaertner via fpc-devel wrote:
>>>>> Hi,
>>>>>
>>>>> Unit shlobj has:
>>>>>
>>>>>       SIGDN      = longint;
>>>>>
>>>>> But the constants are for example:
>>>>>
>>>>> SIGDN_FILESYSPATH               = $80058000;
>>>>>
>>>>>
>>>>> Maybe SIGDN must be DWord?
>>>>>
>>>>> Mattias
>>>>>
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