[E0323] Implemented associated const, expected another trait

[MahadMuhammad]

Const is not member of trait E0323

• Refactored Error message similiar to rustc.

---

Code tested from E0323:

// https://doc.rust-lang.org/error_codes/E0323.html
#![allow(unused)]
fn main() {
trait Foo {
    type N;
}

struct Bar;

impl Foo for Bar {
    const N : u32 = 0; // { dg-error "item .N. is an associated const, which does not match its trait .Foo." }
    // error: item `N` is an associated const, which doesn't match its
    //        trait `<Bar as Foo>`
}
}

---

Output:

/home/mahad/Desktop/mahad/gccrs/gcc/testsuite/rust/compile/non_member_const.rs:11:5: error: item 'N' is an associated const, which does not match its trait 'Foo' [E0323]
compiler exited with status 1
PASS: rust/compile/non_member_const.rs  (test for errors, line 11)
PASS: rust/compile/non_member_const.rs (test for excess errors)

---

gcc/rust/ChangeLog:

* typecheck/rust-hir-type-check-implitem.cc (TypeCheckImplItemWithTrait::visit): called error function.

gcc/testsuite/ChangeLog:

* rust/compile/non_member_const.rs: New test.

[MahadMuhammad]

• Refactored Error message, similiar to rustc.
• With a little difference,
• The diff of rustc and gccrs error is:

# gccrs
+ item ‘N’ is an associated const, which does not match its trait ‘Foo’  

- item `N` is an associated const, which doesn't match its trait `Foo`

Is there a way to add single apostrophe, in the error message:

../../gccrs/gcc/rust/typecheck/rust-hir-type-check-implitem.cc:398:68: warning: bare apostrophe ‘'’ in format [-Wformat-diag]
  398 |                      "item %<%s%> is an associated const, which doe's not match "
      |                                                                    ^
../../gccrs/gcc/rust/typecheck/rust-hir-type-check-implitem.cc:398:22: note: if avoiding the apostrophe is not feasible, enclose it in a pair of ‘%<’ and ‘%>’ directives instead
  398 |                      "item %<%s%> is an associated const, which doe's not match "
      |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  399 |                      "its trait %<%s%>",
      |                      ~~~~~~~~~~~~~~~~~~

[CohenArthur]

the grammar you used is correct, no need to add a single apostrophe?

[MahadMuhammad]

@CohenArthur, Yeah there is no need to add a single apostrophe. But it would be better to add, then the whole message will be exactly similiar to rustc..

[CohenArthur]

the grammar you used is correct, no need to add a single apostrophe?

[CohenArthur]

I liked this error message a little more personally :D but that's just nitpicking haha

[MahadMuhammad]

@CohenArthur We accidently merged wrong error message & error code in this PR :(

The error code should be E0438 and previous message was also wrong. For this error code E0323, we need to do some extra work. I'll fix this in some other PR :)

[CohenArthur]

@CohenArthur We accidently merged wrong error message & error code in this PR :(

The error code should be E0438 and previous message was also wrong. For this error code E0323, we need to do some extra work. I'll fix this in some other PR :)

that's okay, good catch! can you open an issue so we don't forget to address it?