ast_validation: tweak diagnostic output

Author: Centril

src/librustc_ast_passes/ast_validation.rs

@@ -223,21 +223,29 @@ impl<'a> AstValidator<'a> {
 
     fn check_trait_fn_not_async(&self, fn_span: Span, asyncness: Async) {
         if let Async::Yes { span, .. } = asyncness {
-            struct_span_err!(self.session, fn_span, E0706, "trait fns cannot be declared `async`")
-                .span_label(span, "`async` because of this")
-                .note("`async` trait functions are not currently supported")
-                .note(
-                    "consider using the `async-trait` crate: https://crates.io/crates/async-trait",
-                )
-                .emit();
+            struct_span_err!(
+                self.session,
+                fn_span,
+                E0706,
+                "functions in traits cannot be declared `async`"
+            )
+            .span_label(span, "`async` because of this")
+            .note("`async` trait functions are not currently supported")
+            .note("consider using the `async-trait` crate: https://crates.io/crates/async-trait")
+            .emit();
         }
     }
 
     fn check_trait_fn_not_const(&self, constness: Const) {
         if let Const::Yes(span) = constness {
-            struct_span_err!(self.session, span, E0379, "trait fns cannot be declared const")
-                .span_label(span, "trait fns cannot be const")
-                .emit();
+            struct_span_err!(
+                self.session,
+                span,
+                E0379,
+                "functions in traits cannot be declared const"
+            )
+            .span_label(span, "functions in traits cannot be const")
+            .emit();
         }
     }
 
@@ -513,8 +521,11 @@ impl<'a> AstValidator<'a> {
             for param in &generics.params {
                 if let GenericParamKind::Const { .. } = param.kind {
                     self.err_handler()
-                        .struct_span_err(span, "const parameters are not permitted in `const fn`")
-                        .span_label(const_span, "`const fn` because of this")
+                        .struct_span_err(
+                            span,
+                            "const parameters are not permitted in const functions",
+                        )
+                        .span_label(const_span, "`const` because of this")
                         .emit();
                 }
             }

src/test/ui/async-await/async-trait-fn.rs

@@ -1,7 +1,7 @@
 // edition:2018
 trait T {
-    async fn foo() {} //~ ERROR trait fns cannot be declared `async`
-    async fn bar(&self) {} //~ ERROR trait fns cannot be declared `async`
+    async fn foo() {} //~ ERROR functions in traits cannot be declared `async`
+    async fn bar(&self) {} //~ ERROR functions in traits cannot be declared `async`
 }
 
 fn main() {}

src/test/ui/async-await/async-trait-fn.stderr

@@ -1,4 +1,4 @@
-error[E0706]: trait fns cannot be declared `async`
+error[E0706]: functions in traits cannot be declared `async`
   --> $DIR/async-trait-fn.rs:3:5
    |
 LL |     async fn foo() {}
@@ -9,7 +9,7 @@ LL |     async fn foo() {}
    = note: `async` trait functions are not currently supported
    = note: consider using the `async-trait` crate: https://crates.io/crates/async-trait
 
-error[E0706]: trait fns cannot be declared `async`
+error[E0706]: functions in traits cannot be declared `async`
   --> $DIR/async-trait-fn.rs:4:5
    |
 LL |     async fn bar(&self) {}

src/test/ui/async-await/edition-deny-async-fns-2015.rs

@@ -16,7 +16,7 @@ impl Foo {
 
 trait Bar {
     async fn foo() {} //~ ERROR `async fn` is not permitted in the 2015 edition
-                      //~^ ERROR trait fns cannot be declared `async`
+                      //~^ ERROR functions in traits cannot be declared `async`
 }
 
 fn main() {

src/test/ui/async-await/edition-deny-async-fns-2015.stderr

@@ -88,7 +88,7 @@ LL |             async fn bar() {}
    = help: set `edition = "2018"` in `Cargo.toml`
    = note: for more on editions, read https://doc.rust-lang.org/edition-guide
 
-error[E0706]: trait fns cannot be declared `async`
+error[E0706]: functions in traits cannot be declared `async`
   --> $DIR/edition-deny-async-fns-2015.rs:18:5
    |
 LL |     async fn foo() {}

src/test/ui/const-generics/const-fn-with-const-param.rs

@@ -2,7 +2,7 @@
 //~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
 
 const fn const_u32_identity<const X: u32>() -> u32 {
-    //~^ ERROR const parameters are not permitted in `const fn`
+    //~^ ERROR const parameters are not permitted in const functions
     X
 }
 

src/test/ui/const-generics/const-fn-with-const-param.stderr

@@ -1,10 +1,10 @@
-error: const parameters are not permitted in `const fn`
+error: const parameters are not permitted in const functions
   --> $DIR/const-fn-with-const-param.rs:4:1
    |
 LL |   const fn const_u32_identity<const X: u32>() -> u32 {
    |   ^----
    |   |
-   |  _`const fn` because of this
+   |  _`const` because of this
    | |
 LL | |
 LL | |     X

src/test/ui/consts/const-fn-mismatch.rs

@@ -10,8 +10,10 @@ trait Foo {
 }
 
 impl Foo for u32 {
-    const fn f() -> u32 { 22 }
-    //~^ ERROR trait fns cannot be declared const
+    const fn f() -> u32 {
+        //~^ ERROR functions in traits cannot be declared const
+        22
+    }
 }
 
-fn main() { }
+fn main() {}

src/test/ui/consts/const-fn-mismatch.stderr

@@ -1,8 +1,8 @@
-error[E0379]: trait fns cannot be declared const
+error[E0379]: functions in traits cannot be declared const
   --> $DIR/const-fn-mismatch.rs:13:5
    |
-LL |     const fn f() -> u32 { 22 }
-   |     ^^^^^ trait fns cannot be const
+LL |     const fn f() -> u32 {
+   |     ^^^^^ functions in traits cannot be const
 
 error: aborting due to previous error
 

src/test/ui/consts/const-fn-not-in-trait.rs

@@ -5,9 +5,11 @@
 
 trait Foo {
     const fn f() -> u32;
-    //~^ ERROR trait fns cannot be declared const
-    const fn g() -> u32 { 0 }
-    //~^ ERROR trait fns cannot be declared const
+    //~^ ERROR functions in traits cannot be declared const
+    const fn g() -> u32 {
+        //~^ ERROR functions in traits cannot be declared const
+        0
+    }
 }
 
-fn main() { }
+fn main() {}