[gcc r14-7830] gccrs: [E0323] Implemented associated const, expected another trait

[gcc r14-7830] gccrs: [E0323] Implemented associated const, expected another trait

[Arthur Cohen]

https://gcc.gnu.org/g:5141707b5b5dcacde76dd0760f6604451f06ef85

commit r14-7830-g5141707b5b5dcacde76dd0760f6604451f06ef85
Author: Muhammad Mahad <mahadtxt@gmail.com>
Date:   Tue Jul 18 18:55:32 2023 +0500

    gccrs: [E0323] Implemented associated const, expected another trait
    
    Refactored Error message similiar to rustc.
    
    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.
    
    Signed-off-by: Muhammad Mahad <mahadtxt@gmail.com>

Diff:
---
 gcc/rust/typecheck/rust-hir-type-check-implitem.cc |  6 ++++--
 gcc/testsuite/rust/compile/non_member_const.rs     | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/gcc/rust/typecheck/rust-hir-type-check-implitem.cc b/gcc/rust/typecheck/rust-hir-type-check-implitem.cc
index b8a73a73111..189dd8797d1 100644
--- a/gcc/rust/typecheck/rust-hir-type-check-implitem.cc
+++ b/gcc/rust/typecheck/rust-hir-type-check-implitem.cc
@@ -389,12 +389,14 @@ TypeCheckImplItemWithTrait::visit (HIR::ConstantItem &constant)
 				       TraitItemReference::TraitItemType::CONST,
 				       &raw_trait_item);
 
-  // unknown trait item
+  // unknown trait item - https://doc.rust-lang.org/error_codes/E0323.html
   if (!found || raw_trait_item->is_error ())
     {
       rich_location r (line_table, constant.get_locus ());
       r.add_range (trait_reference.get_locus ());
-      rust_error_at (r, "constant %<%s%> is not a member of trait %<%s%>",
+      rust_error_at (r, ErrorCode ("E0323"),
+		     "item %qs is an associated const, which does not match "
+		     "its trait %qs",
 		     constant.get_identifier ().as_string ().c_str (),
 		     trait_reference.get_name ().c_str ());
       return;
diff --git a/gcc/testsuite/rust/compile/non_member_const.rs b/gcc/testsuite/rust/compile/non_member_const.rs
new file mode 100644
index 00000000000..b9740025266
--- /dev/null
+++ b/gcc/testsuite/rust/compile/non_member_const.rs
@@ -0,0 +1,15 @@
+// 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>`
+}
+}
\ No newline at end of file