[SOLVED] How to tell if dll is 32-bit or 64-bit

[ASerge]

Test

Code: Pascal  [Select]

1. program Project1;
2. {$APPTYPE CONSOLE}
3.  
4. // Code above paste here
5.  
6. function PEBitnessAsText(V: TPEBitness): string;
7. const
8.   CValue: array [TPEBitness] of string = (
9.     'Unknown', '16 bit', '32 bit', '64 bit');
10. begin
11.   Result := CValue[V];
12. end;
13.  
14. procedure WritelnBitness(const FileName: WideString);
15. begin
16.   Writeln(FileName, ' is ', PEBitnessAsText(GetPEBitness(FileName)));
17. end;
18.  
19. const
20.   CDlls: array [1..5] of WideString = (
21.     'c:\Windows\SysWOW64\netmsg.dll',
22.     'c:\Windows\System32\netmsg.dll',
23.     'c:\Windows\Sysnative\netmsg.dll',
24.     'c:\Windows\twain.dll',
25.     'c:\Windows\twain_32.dll');
26. var
27.   i: Integer;
28. begin
29.   for i := Low(CDlls) to High(CDlls) do
30.     WritelnBitness(CDlls[i]);
31.   Readln;
32. end.

Result with 64 compiler:
c:\Windows\SysWOW64\netmsg.dll is 32 bit
c:\Windows\System32\netmsg.dll is 64 bit
c:\Windows\Sysnative\netmsg.dll is Unknown
c:\Windows\twain.dll is 16 bit
c:\Windows\twain_32.dll is 32 bit

Result with 32 compiler:
c:\Windows\SysWOW64\netmsg.dll is 32 bit
c:\Windows\System32\netmsg.dll is 32 bit
c:\Windows\Sysnative\netmsg.dll is 64 bit
c:\Windows\twain.dll is 16 bit
c:\Windows\twain_32.dll is 32 bit

[GetMem]

@Zoran
I'm asking because in the first version (see this post), there was a protective block, and I'm affraid that it was maybe inserted when the function returned 16-bit when it was not a valid 16-bit dll (I don't know, but it just looks like that...).

No, that was a logical error. My original code would fail to detect a 16 bit PE as you correctly pointed out in one of your previous post. I don't think it's a way to detect a corrupted 16/32/64 PE other then checking if a valid  IMAGE_DOS_SIGNATURE,  IMAGE_NT_SIGNATURE, etc... exist. I meant PE_UNKNOWN for special cases when the path to file is invalid or the memory map could not be crated or something else.

@ASerge
Multiple CloseHandle calls can be excluded.

Yes, your code is more compact, however I prefer a slightly verbose approach. It's much easier this way  to figure out what the code does at a later time. For example instead of:

Code: Pascal  [Select]

1. if (Something) then
2.   if (SomethingElse) then
3.     DoThis
4.   else
5.     DoThat;

I always do:

Code: Pascal  [Select]

1. if (Something) then
2. begin
3.   if (SomethingElse) then
4.     DoThis
5.   else
6.     DoThat;
7. end;

Which is code redundancy, but visually is more appealing to me, but I guess is just a personal preference.

[Thaddy]

That's why I like editors with a line length of at least 1024. So I definitely know that my Pascal code intended to have a linebreak and not white  space, but I guess is just a personal preference.