Rollup merge of rust-lang#134701 - compiler-errors:non-const-def-descr, r=Urgau,fmease

Correctly note item kind in `NonConstFunctionCall` error message

Don't just call everything a "`fn`". This is more consistent with the error message we give for conditionally-const items, which do note the item's def kind.

r? fmease, this is a prerequisite for making those `~const PartialEq` error messages better. Re-roll if you're busy or don't want to review this.

Author: Zalathar

compiler/rustc_const_eval/messages.ftl

@@ -253,7 +253,7 @@ const_eval_non_const_fmt_macro_call =
     cannot call non-const formatting macro in {const_eval_const_context}s
 
 const_eval_non_const_fn_call =
-    cannot call non-const fn `{$def_path_str}` in {const_eval_const_context}s
+    cannot call non-const {$def_descr} `{$def_path_str}` in {const_eval_const_context}s
 
 const_eval_non_const_impl =
     impl defined here, but it is not `const`

compiler/rustc_const_eval/src/check_consts/ops.rs

@@ -304,6 +304,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallNonConst<'tcx> {
             }
             _ => ccx.dcx().create_err(errors::NonConstFnCall {
                 span,
+                def_descr: ccx.tcx.def_descr(callee),
                 def_path_str: ccx.tcx.def_path_str_with_args(callee, args),
                 kind: ccx.const_kind(),
             }),

compiler/rustc_const_eval/src/errors.rs

@@ -192,6 +192,7 @@ pub(crate) struct NonConstFnCall {
     #[primary_span]
     pub span: Span,
     pub def_path_str: String,
+    pub def_descr: &'static str,
     pub kind: ConstContext,
 }
 

compiler/rustc_error_codes/src/error_codes/E0015.md

@@ -7,7 +7,7 @@ fn create_some() -> Option<u8> {
     Some(1)
 }
 
-// error: cannot call non-const fn `create_some` in constants
+// error: cannot call non-const function `create_some` in constants
 const FOO: Option<u8> = create_some();
 ```
 

tests/run-make/const-trait-stable-toolchain/const-super-trait-nightly-disabled.stderr

@@ -52,7 +52,7 @@ help: enable `#![feature(const_trait_impl)]` in your crate and mark `Bar` as `#[
 LL | #[const_trait] trait Bar: ~const Foo {}
    | ++++++++++++++
 
-error[E0015]: cannot call non-const fn `<T as Foo>::a` in constant functions
+error[E0015]: cannot call non-const method `<T as Foo>::a` in constant functions
   --> const-super-trait.rs:10:7
    |
 LL |     x.a();

tests/run-make/const-trait-stable-toolchain/const-super-trait-nightly-enabled.stderr

@@ -32,7 +32,7 @@ help: mark `Bar` as `#[const_trait]` to allow it to have `const` implementations
 LL | #[const_trait] trait Bar: ~const Foo {}
    | ++++++++++++++
 
-error[E0015]: cannot call non-const fn `<T as Foo>::a` in constant functions
+error[E0015]: cannot call non-const method `<T as Foo>::a` in constant functions
   --> const-super-trait.rs:10:7
    |
 LL |     x.a();

tests/run-make/const-trait-stable-toolchain/const-super-trait-stable-disabled.stderr

@@ -50,7 +50,7 @@ note: `Bar` can't be used with `~const` because it isn't annotated with `#[const
 7 | trait Bar: ~const Foo {}
   | ^^^^^^^^^^^^^^^^^^^^^
 
-error[E0015]: cannot call non-const fn `<T as Foo>::a` in constant functions
+error[E0015]: cannot call non-const method `<T as Foo>::a` in constant functions
   --> const-super-trait.rs:10:7
    |
 10 |     x.a();

tests/run-make/const-trait-stable-toolchain/const-super-trait-stable-enabled.stderr

@@ -40,7 +40,7 @@ note: `Bar` can't be used with `~const` because it isn't annotated with `#[const
 7 | trait Bar: ~const Foo {}
   | ^^^^^^^^^^^^^^^^^^^^^
 
-error[E0015]: cannot call non-const fn `<T as Foo>::a` in constant functions
+error[E0015]: cannot call non-const method `<T as Foo>::a` in constant functions
   --> const-super-trait.rs:10:7
    |
 10 |     x.a();

tests/ui/asm/non-const.rs

@@ -8,4 +8,4 @@ fn main() {}
 fn non_const_fn(x: i32) -> i32 { x }
 
 global_asm!("/* {} */", const non_const_fn(0));
-//~^ERROR: cannot call non-const fn
+//~^ERROR: cannot call non-const function

tests/ui/asm/non-const.stderr

@@ -1,4 +1,4 @@
-error[E0015]: cannot call non-const fn `non_const_fn` in constants
+error[E0015]: cannot call non-const function `non_const_fn` in constants
   --> $DIR/non-const.rs:10:31
    |
 LL | global_asm!("/* {} */", const non_const_fn(0));