Error Variadic Parameters - [E0045]

[MahadMuhammad]

Variadic Parameters Used on Non-C ABI Function

• Fixing this error will improve gccrs to emit error codes similiar to rustc.
• You can view the same on compiler-explorer

I tried this code from E0045:

// https://doc.rust-lang.org/error_codes/E0045.html
#![allow(unused)]
fn main() {
extern "Rust" {
    fn foo(x: u8, ...); // error!
}
}

---

I expected to see this happen:

• Give error like rustc:

error[E0045]: C-variadic function must have C or cdecl calling convention
 --> <source>:4:5
  |
4 |     fn foo(x: u8, ...); // error!
  |     ^^^^^^^^^^^^^^^^^^^ C-variadics require C or cdecl calling convention

error: aborting due to previous error

For more information about this error, try `rustc --explain E0045`.
Compiler returned: 1

---

Instead, this happened:

• Compiled Successfully.

Compiler returned: 0

---

Meta

• What version of Rust GCC were you using, git sha 5406b63.
• Godbolt version : gccrs (Compiler-Explorer-Build-gcc-2f91d511200bf85558c9013b09a458c06edd1e02-binutils-2.40) 13.0.1 20230417 (experimental)

---

[philberty]

We need to add an ABI check in type check of call expressions:

https://github.com/Rust-GCC/gccrs/blob/5406b633a1f5e6e3ae8da02589adf4ea003dec12/gcc/rust/typecheck/rust-tyty-call.cc#L92C30-L92C30

we can check of the function we are type checking is varadic this is missing another if statement for:

if (type.get_abi () != ABI::C)

[philberty]

@MahadMuhammad ^^^

[philberty]

gccrs/gcc/rust/typecheck/rust-hir-type-check-implitem.cc

Line 148 in 5406b63

auto fnType = new TyTy::FnType (function.get_mappings ().get_hirid (),