Why does gcc ignore attribute((stdcall))?

Question

When I compile the following C source with gcc version 8.1.1, I get a warning: ‘stdcall’ attribute ignored [-Wattributes].

Why does gcc choose to ignore this attribute and what can I do to make it accept it?

__attribute__((stdcall)) int S(int a) {
    return a * (a+1);
}

int main() {
    return S(6);
}

What architecture are you compiling for?

a3f
– a3f

2018-10-09 05:27:11 +00:00
Commented Oct 9, 2018 at 5:27 — a3f
– a3f, Commented Oct 9, 2018 at 5:27
Move to a 32-bit x86 platform.

n. m. could be an AI
– n. m. could be an AI

2018-10-09 05:27:57 +00:00
Commented Oct 9, 2018 at 5:27 — n. m. could be an AI
– n. m. could be an AI, Commented Oct 9, 2018 at 5:27

Community · Accepted Answer · 2020-06-20 09:12:55Z

8

The gcc documentation says:

stdcall

On x86-32 targets, the stdcall attribute causes the compiler to assume that the called function pops off the stack space used to pass arguments, unless it takes a variable number of arguments.

(Emphasis mine.)

So if you're not compiling for a 32-bit machine, stdcall can't be used.

edited Jun 20, 2020 at 9:12

CommunityBot

11 silver badge

answered Oct 9, 2018 at 5:29

melpomene

86.2k8 gold badges96 silver badges155 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

René Nyffenegger Over a year ago

Is there a technical reason that stdcall is not possible on non-x86-32 targets?

melpomene Over a year ago

@RenéNyffenegger x86-64 doesn't pass arguments on the stack (or rather, it prefers using registers before using the stack), so there's little point in defining and using different incompatible conventions for adjusting the stack.

René Nyffenegger Over a year ago

Thanks for clearing that up to me. I was completely unaware of the shift between 32 and 64 bit x86 regarding calling conventions.

CroCo Over a year ago

Is it possible to turn this warning off?

Collectives™ on Stack Overflow

Why does gcc ignore attribute((stdcall))?

1 Answer 1

4 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related