Auto merge of #38890 - petrochenkov:noresolve, r=nrc

resolve: Do not use "resolve"/"resolution" in error messages

Use less jargon-y wording instead.
`cannot find <struct> <S> in <this scope>` and `cannot find <struct> <S> in <module a::b>` are used for base messages (this also harmonizes nicely with "you can import it into scope" suggestions) and `not found in <this scope>` and `not found in <a::b>` are used for short labels in fall-back case.
I tweaked some other diagnostics to avoid using "resolve" (see, e.g., `librustc_resolve/macros.rs`), but haven't touched messages for imports.

Closes #38750
r? @nrc

Author: bors

src/librustc_resolve/lib.rs

@@ -2090,10 +2090,25 @@ impl<'a> Resolver<'a> {
             let expected = source.descr_expected();
             let path_str = names_to_string(path);
             let code = source.error_code(def.is_some());
-            let base_msg = if let Some(def) = def {
-                format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str)
+            let (base_msg, fallback_label) = if let Some(def) = def {
+                (format!("expected {}, found {} `{}`", expected, def.kind_name(), path_str),
+                 format!("not a {}", expected))
             } else {
-                format!("unresolved {} `{}`", expected, path_str)
+                let item_str = path[path.len() - 1];
+                let (mod_prefix, mod_str) = if path.len() == 1 {
+                    (format!(""), format!("this scope"))
+                } else if path.len() == 2 && path[0].name == keywords::CrateRoot.name() {
+                    (format!(""), format!("the crate root"))
+                } else {
+                    let mod_path = &path[..path.len() - 1];
+                    let mod_prefix = match this.resolve_path(mod_path, Some(TypeNS), None) {
+                        PathResult::Module(module) => module.def(),
+                        _ => None,
+                    }.map_or(format!(""), |def| format!("{} ", def.kind_name()));
+                    (mod_prefix, format!("`{}`", names_to_string(mod_path)))
+                };
+                (format!("cannot find {} `{}` in {}{}", expected, item_str, mod_prefix, mod_str),
+                 format!("not found in {}", mod_str))
             };
             let mut err = this.session.struct_span_err_with_code(span, &base_msg, code);
 
@@ -2183,12 +2198,8 @@ impl<'a> Resolver<'a> {
                 }
             }
 
-            // Fallback labels.
-            if def.is_some() {
-                err.span_label(span, &format!("not a {}", expected));
-            } else {
-                err.span_label(span, &format!("no resolution found"));
-            }
+            // Fallback label.
+            err.span_label(span, &fallback_label);
             err
         };
         let report_errors = |this: &mut Self, def: Option<Def>| {
@@ -2989,8 +3000,8 @@ impl<'a> Resolver<'a> {
             let participle = |binding: &NameBinding| {
                 if binding.is_import() { "imported" } else { "defined" }
             };
-            let msg1 = format!("`{}` could resolve to the name {} here", name, participle(b1));
-            let msg2 = format!("`{}` could also resolve to the name {} here", name, participle(b2));
+            let msg1 = format!("`{}` could refer to the name {} here", name, participle(b1));
+            let msg2 = format!("`{}` could also refer to the name {} here", name, participle(b2));
             let note = if !lexical && b1.is_glob_import() {
                 format!("consider adding an explicit import of `{}` to disambiguate", name)
             } else if let Def::Macro(..) = b1.def() {

src/librustc_resolve/macros.rs

@@ -380,8 +380,8 @@ impl<'a> Resolver<'a> {
                 MacroBinding::Modern(binding) => (binding.span, "imported"),
                 MacroBinding::Legacy(binding) => (binding.span, "defined"),
             };
-            let msg1 = format!("`{}` could resolve to the macro {} here", ident, participle);
-            let msg2 = format!("`{}` could also resolve to the macro imported here", ident);
+            let msg1 = format!("`{}` could refer to the macro {} here", ident, participle);
+            let msg2 = format!("`{}` could also refer to the macro imported here", ident);
             self.session.struct_span_err(span, &format!("`{}` is ambiguous", ident))
                 .span_note(legacy_span, &msg1)
                 .span_note(resolution.span, &msg2)

src/test/compile-fail-fulldeps/macro-crate-doesnt-resolve.rs

@@ -14,5 +14,5 @@
 extern crate macro_crate_test;
 
 fn main() {
-    macro_crate_test::foo(); //~ ERROR unresolved function `macro_crate_test::foo`
+    macro_crate_test::foo(); //~ ERROR cannot find function `foo` in module `macro_crate_test`
 }

src/test/compile-fail-fulldeps/qquote.rs

@@ -39,6 +39,6 @@ fn main() {
 
     assert_eq!(pprust::expr_to_string(&*quote_expr!(&cx, 23)), "23");
 
-    let expr = quote_expr!(&cx, 2 - $abcd + 7); //~ ERROR unresolved value `abcd`
+    let expr = quote_expr!(&cx, 2 - $abcd + 7); //~ ERROR cannot find value `abcd` in this scope
     assert_eq!(pprust::expr_to_string(&*expr), "2 - $abcd + 7");
 }

src/test/compile-fail/associated-path-shl.rs

@@ -11,10 +11,10 @@
 // Check that associated paths starting with `<<` are successfully parsed.
 
 fn main() {
-    let _: <<A>::B>::C; //~ ERROR unresolved type `A`
-    let _ = <<A>::B>::C; //~ ERROR unresolved type `A`
-    let <<A>::B>::C; //~ ERROR unresolved type `A`
-    let 0 ... <<A>::B>::C; //~ ERROR unresolved type `A`
+    let _: <<A>::B>::C; //~ ERROR cannot find type `A` in this scope
+    let _ = <<A>::B>::C; //~ ERROR cannot find type `A` in this scope
+    let <<A>::B>::C; //~ ERROR cannot find type `A` in this scope
+    let 0 ... <<A>::B>::C; //~ ERROR cannot find type `A` in this scope
                            //~^ ERROR only char and numeric types are allowed in range patterns
-    <<A>::B>::C; //~ ERROR unresolved type `A`
+    <<A>::B>::C; //~ ERROR cannot find type `A` in this scope
 }

src/test/compile-fail/associated-types-eq-1.rs

@@ -17,7 +17,7 @@ pub trait Foo {
 }
 
 fn foo2<I: Foo>(x: I) {
-    let _: A = x.boo(); //~ ERROR unresolved type `A`
+    let _: A = x.boo(); //~ ERROR cannot find type `A` in this scope
 }
 
 pub fn main() {}

src/test/compile-fail/bad-expr-path.rs

@@ -12,7 +12,7 @@ mod m1 {}
 
 fn main(arguments: Vec<String>) { //~ ERROR main function has wrong type
     log(debug, m1::arguments);
-    //~^ ERROR unresolved function `log`
-    //~| ERROR unresolved value `debug`
-    //~| ERROR unresolved value `m1::arguments`
+    //~^ ERROR cannot find function `log` in this scope
+    //~| ERROR cannot find value `debug` in this scope
+    //~| ERROR cannot find value `arguments` in module `m1`
 }

src/test/compile-fail/bad-expr-path2.rs

@@ -14,7 +14,7 @@ mod m1 {
 
 fn main(arguments: Vec<String>) { //~ ERROR main function has wrong type
     log(debug, m1::arguments);
-    //~^ ERROR unresolved function `log`
-    //~| ERROR unresolved value `debug`
+    //~^ ERROR cannot find function `log` in this scope
+    //~| ERROR cannot find value `debug` in this scope
     //~| ERROR expected value, found module `m1::arguments`
 }

src/test/compile-fail/class-missing-self.rs

@@ -16,8 +16,8 @@ impl cat {
     fn sleep(&self) { loop{} }
     fn meow(&self) {
       println!("Meow");
-      meows += 1; //~ ERROR unresolved value `meows`
-      sleep();     //~ ERROR unresolved function `sleep`
+      meows += 1; //~ ERROR cannot find value `meows` in this scope
+      sleep();     //~ ERROR cannot find function `sleep` in this scope
     }
 
 }

src/test/compile-fail/coherence-error-suppression.rs

@@ -16,7 +16,7 @@ impl Foo for i8 {}
 impl Foo for i16 {}
 impl Foo for i32 {}
 impl Foo for i64 {}
-impl Foo for DoesNotExist {} //~ ERROR unresolved type `DoesNotExist`
+impl Foo for DoesNotExist {} //~ ERROR cannot find type `DoesNotExist` in this scope
 impl Foo for u8 {}
 impl Foo for u16 {}
 impl Foo for u32 {}