The Old New Thing

What happens when you get dllimport wrong?

July 26, 2006 Jul 26, 2006 07/26/06
Raymond Chen
Now that we've learned what the declaration specifier does, what if you get it wrong? If you forget to declare a function as , then you're basically making the compiler act like a naive compiler that doesn't understand . When the linker goes to resolve the external reference for the function, it will use the stub from the import library, and...

If you know German, the world is, well, slightly more confusing

July 25, 2006 Jul 25, 2006 07/25/06
Raymond Chen
While it may be true that if you know Swedish, the world is funnier, I have to admit that my knowledge of German only served to create momentary confusion. When I saw the headline that the head of BetonSports was arrested, I thought to myself, "Who the heck would have a web site devoted to sports in concrete?" That's because the German word...

Issues related to forcing a stub to be created for an imported function

July 25, 2006 Jul 25, 2006 07/25/06
Raymond Chen
I noted last time that you can concoct situations that force the creation of a stub for an imported function. For example, if you declare a global function pointer variable: then the C compiler is forced to generate the stub and assign the address of the stub to the variable. That's the best it can do, since the loader will patch up only...

Raise la lanterne rouge

July 24, 2006 Jul 24, 2006 07/24/06
Raymond Chen
Sure, everybody knows that Floyd Landis won this year's Tour de France. But what about the guy who came in last? While the race leader wears the maillot jaune (yellow jersey), the person at the bottom of the pack is saddled with the lanterne rouge (red lantern), after the lamp that hangs on the back of a train. This year's "winner" is Wim ...

How a less naive compiler calls an imported function

July 24, 2006 Jul 24, 2006 07/24/06
Raymond Chen
If a function is declared with the declaration specifier, this instructs the Visual Studio C/C++ compiler that the function in question is an imported function rather than a normal function with external linkage. With this additional information, the compiler generates slightly different code when it needs to reference an imported function, ...

Floyd Landis stuns everybody on stage 17; Raymond less impressive

July 21, 2006 Jul 21, 2006 07/21/06
Raymond Chen
Wow. I delayed my departure for work Thursday morning until the results were in. And then I was inspired by Floyd's fantastic performance to kick it up a notch on one of the hills on my route, only to find about two thirds of the way up that there's a reason I don't normally go up the hill that fast... (On an unrelated note, a mini-van tried...

Calling an imported function, the naive way

July 21, 2006 Jul 21, 2006 07/21/06
Raymond Chen
An import library resolves symbols for imported functions, but it isn't consulted until the link phase. Let's consider a naive implementation where the compiler is blissfully unaware of the existence of imported functions. In the 16-bit world, this caused no difficulty at all. The compiler generated a far call instruction and left an external...

Buy me some peanuts and a set of double-pointed 2's

July 20, 2006 Jul 20, 2006 07/20/06
Raymond Chen
It's the second annual Stitch 'n Pitch at Safeco Field. Stitch n' Pitch events for other cities can be found on the Stitch n' Pitch web site. (Channeling Lynne Truss: Ahem, people, the spelling of the middle word is 'n' with an apostrophe fore and aft.) [10am: Fixed sepleling.] Seattle Times readers Dave Butner and Mike Wilson took issue ...

Rethinking the way DLL exports are resolved for 32-bit Windows

July 20, 2006 Jul 20, 2006 07/20/06
Raymond Chen
Over the past few days we've learned how 16-bit Windows exported and imported functions from DLLs and that the way functions are exported from 32-bit DLLs matches the 16-bit method reasonably well. But the 16-bit way functions are imported simply doesn't work in the 32-bit world. Recall that in 16-bit Windows, the fixups for an imported ...