[fpc-devel] 32 bit fpc gives no warning for cast that fails on 64 bit?

Martin fpc at mfriebe.de
Sun Apr 18 00:57:01 CEST 2010


On 17/04/2010 23:48, Jonas Maebe wrote:
> On 17 Apr 2010, at 21:47, Martin wrote:
>
>    
>> Maybe it's my setting, but I get other warnings, hints even..
>>
>> var
>>   p: Pointer;
>>   e: TEnumType;
>> begin
>>   e:= TEnumType(p);
>>
>> didn't give me any warning (2.4.0, 2.5.1), but it fails (so I am told) on 64bit, [ Illegal type conversion: "^untyped" to "<enumeration type>"]
>>
>> If untyped^ to enum is forbiden, then why does it even *work* on 32 bit? (not to speak, of not giving a warning?)
>>      
> It works in 32 bit because the default size of enumeration types is 4 bytes (also on 64 bit platforms, to avoid problems with reading binary files containing enumeration types), and explicitly type casting one type to another type of the same size is always allowed.
>    

ah yes, I see, so a warning would upset many people using other 64bit 
unsave code....
My initial confusion was when I saw the error message => I thought the 
problem was because it was untyped (and it was untyped in 32 bit too


Maybe at some point a switch -w#### some way to enable warnings for code 
that isn't 64/32 compatible?

Martin



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