Do not emit suggestions to import assoc const or fn if import_trait_associated_function is not enabled

Author: frank-king

compiler/rustc_resolve/src/diagnostics.rs

@@ -1183,7 +1183,11 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             let in_module_is_extern = !in_module.def_id().is_local();
             in_module.for_each_child(self, |this, ident, ns, name_binding| {
                 // avoid non-importable candidates
-                if !name_binding.is_importable() {
+                if !name_binding.is_importable()
+                    // FIXME(import_trait_associated_functions): remove this when `import_trait_associated_functions` is stable
+                    || name_binding.is_assoc_const_or_fn()
+                        && !this.tcx.features().import_trait_associated_functions()
+                {
                     return;
                 }
 

compiler/rustc_resolve/src/lib.rs

@@ -923,6 +923,8 @@ impl<'ra> NameBindingData<'ra> {
         !matches!(self.res(), Res::Def(DefKind::AssocTy, _))
     }
 
+    // FIXME(import_trait_associated_functions): associate `const` or `fn` are not importable unless
+    // the feature `import_trait_associated_functions` is enable
     fn is_assoc_const_or_fn(&self) -> bool {
         matches!(self.res(), Res::Def(DefKind::AssocConst | DefKind::AssocFn, _))
     }

tests/ui/associated-type-bounds/return-type-notation/not-a-method.stderr

@@ -15,11 +15,6 @@ error[E0576]: cannot find function `method` in this scope
    |
 LL |     method(..): Send,
    |     ^^^^^^ not found in this scope
-   |
-help: consider importing this associated function
-   |
-LL + use Tr::method;
-   |
 
 error[E0412]: cannot find type `method` in this scope
   --> $DIR/not-a-method.rs:36:5

tests/ui/delegation/bad-resolve.stderr

@@ -62,11 +62,6 @@ error[E0425]: cannot find function `foo` in this scope
    |
 LL |     reuse foo { &self.0 }
    |           ^^^ not found in this scope
-   |
-help: consider importing this associated function
-   |
-LL + use Trait::foo;
-   |
 
 error[E0425]: cannot find function `foo2` in trait `Trait`
   --> $DIR/bad-resolve.rs:37:18

tests/ui/delegation/explicit-paths.stderr

@@ -21,58 +21,42 @@ error[E0425]: cannot find function `foo4` in `S`
    |
 LL |     reuse S::foo4;
    |              ^^^^ not found in `S`
-   |
-note: associated function `trait_assoc_fn_to_other::Trait2::foo4` exists but is inaccessible
-  --> $DIR/explicit-paths.rs:65:9
-   |
-LL |         reuse F::foo4 { &F }
-   |         ^^^^^^^^^^^^^ not accessible
 
 error[E0425]: cannot find function `foo4` in `F`
   --> $DIR/explicit-paths.rs:38:18
    |
 LL |         reuse F::foo4 { &self.0 }
    |                  ^^^^ not found in `F`
    |
-note: these items exist but are inaccessible
+note: function `fn_to_other::foo4` exists but is inaccessible
   --> $DIR/explicit-paths.rs:27:5
    |
 LL |     reuse S::foo4;
-   |     ^^^^^^^^^^^^^^ `fn_to_other::foo4`: not accessible
-...
-LL |         reuse F::foo4 { &F }
-   |         ^^^^^^^^^^^^^ `trait_assoc_fn_to_other::Trait2::foo4`: not accessible
+   |     ^^^^^^^^^^^^^^ not accessible
 
 error[E0425]: cannot find function `foo4` in `F`
   --> $DIR/explicit-paths.rs:51:18
    |
 LL |         reuse F::foo4 { &self.0 }
    |                  ^^^^ not found in `F`
    |
-note: these items exist but are inaccessible
+note: function `fn_to_other::foo4` exists but is inaccessible
   --> $DIR/explicit-paths.rs:27:5
    |
 LL |     reuse S::foo4;
-   |     ^^^^^^^^^^^^^^ `fn_to_other::foo4`: not accessible
-...
-LL |         reuse F::foo4 { &F }
-   |         ^^^^^^^^^^^^^ `trait_assoc_fn_to_other::Trait2::foo4`: not accessible
+   |     ^^^^^^^^^^^^^^ not accessible
 
 error[E0425]: cannot find function `foo4` in `F`
   --> $DIR/explicit-paths.rs:65:18
    |
 LL |         reuse F::foo4 { &F }
    |                  ^^^^ not found in `F`
    |
-help: consider importing this associated function
-   |
-LL +     use trait_assoc_fn_to_other::Trait2::foo4;
-   |
-help: if you import `foo4`, refer to it directly
-   |
-LL -         reuse F::foo4 { &F }
-LL +         reuse foo4 { &F }
+note: function `fn_to_other::foo4` exists but is inaccessible
+  --> $DIR/explicit-paths.rs:27:5
    |
+LL |     reuse S::foo4;
+   |     ^^^^^^^^^^^^^^ not accessible
 
 error[E0119]: conflicting implementations of trait `Trait` for type `S`
   --> $DIR/explicit-paths.rs:74:5

tests/ui/delegation/ice-issue-124342.stderr

@@ -3,16 +3,6 @@ error[E0425]: cannot find function `foo` in module `to_reuse`
    |
 LL |     reuse to_reuse::foo { foo }
    |                     ^^^ not found in `to_reuse`
-   |
-help: consider importing this associated function
-   |
-LL + use Trait::foo;
-   |
-help: if you import `foo`, refer to it directly
-   |
-LL -     reuse to_reuse::foo { foo }
-LL +     reuse foo { foo }
-   |
 
 error[E0425]: cannot find value `foo` in this scope
   --> $DIR/ice-issue-124342.rs:7:27
@@ -24,10 +14,6 @@ help: you might have meant to refer to the associated function
    |
 LL |     reuse to_reuse::foo { Self::foo }
    |                           ++++++
-help: consider importing this associated function
-   |
-LL + use Trait::foo;
-   |
 
 error: aborting due to 2 previous errors
 

tests/ui/macros/rfc-3086-metavar-expr/syntax-errors.stderr

@@ -313,21 +313,6 @@ LL |     unknown_metavar!(a);
    |
    = note: this error originates in the macro `unknown_metavar` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0425]: cannot find function `count` in this scope
-  --> $DIR/syntax-errors.rs:23:30
-   |
-LL |     ( $( $i:ident ),* ) => { count(i) };
-   |                              ^^^^^ not found in this scope
-...
-LL |     no_curly__no_rhs_dollar__round!(a, b, c);
-   |     ---------------------------------------- in this macro invocation
-   |
-   = note: this error originates in the macro `no_curly__no_rhs_dollar__round` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing this associated function
-   |
-LL + use std::iter::Iterator::count;
-   |
-
 error[E0425]: cannot find value `i` in this scope
   --> $DIR/syntax-errors.rs:23:36
    |
@@ -339,26 +324,39 @@ LL |     no_curly__no_rhs_dollar__round!(a, b, c);
    |
    = note: this error originates in the macro `no_curly__no_rhs_dollar__round` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0425]: cannot find function `count` in this scope
-  --> $DIR/syntax-errors.rs:30:23
+error[E0425]: cannot find value `i` in this scope
+  --> $DIR/syntax-errors.rs:30:29
    |
 LL |     ( $i:ident ) => { count(i) };
-   |                       ^^^^^ not found in this scope
+   |                             ^ not found in this scope
 ...
 LL |     no_curly__no_rhs_dollar__no_round!(a);
    |     ------------------------------------- in this macro invocation
    |
    = note: this error originates in the macro `no_curly__no_rhs_dollar__no_round` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing this associated function
+
+error[E0425]: cannot find value `a` in this scope
+  --> $DIR/syntax-errors.rs:152:37
+   |
+LL |     no_curly__rhs_dollar__no_round!(a);
+   |                                     ^ not found in this scope
+
+error[E0425]: cannot find function `count` in this scope
+  --> $DIR/syntax-errors.rs:23:30
    |
-LL + use std::iter::Iterator::count;
+LL |     ( $( $i:ident ),* ) => { count(i) };
+   |                              ^^^^^ not found in this scope
+...
+LL |     no_curly__no_rhs_dollar__round!(a, b, c);
+   |     ---------------------------------------- in this macro invocation
    |
+   = note: this error originates in the macro `no_curly__no_rhs_dollar__round` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0425]: cannot find value `i` in this scope
-  --> $DIR/syntax-errors.rs:30:29
+error[E0425]: cannot find function `count` in this scope
+  --> $DIR/syntax-errors.rs:30:23
    |
 LL |     ( $i:ident ) => { count(i) };
-   |                             ^ not found in this scope
+   |                       ^^^^^ not found in this scope
 ...
 LL |     no_curly__no_rhs_dollar__no_round!(a);
    |     ------------------------------------- in this macro invocation
@@ -375,16 +373,6 @@ LL |     no_curly__rhs_dollar__no_round!(a);
    |     ---------------------------------- in this macro invocation
    |
    = note: this error originates in the macro `no_curly__rhs_dollar__no_round` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: consider importing this associated function
-   |
-LL + use std::iter::Iterator::count;
-   |
-
-error[E0425]: cannot find value `a` in this scope
-  --> $DIR/syntax-errors.rs:152:37
-   |
-LL |     no_curly__rhs_dollar__no_round!(a);
-   |                                     ^ not found in this scope
 
 error: aborting due to 39 previous errors
 

tests/ui/methods/suggest-method-on-call-for-ambig-receiver.stderr

@@ -3,11 +3,6 @@ error[E0425]: cannot find function `consume` in this scope
    |
 LL |             consume(right);
    |             ^^^^^^^ not found in this scope
-   |
-help: consider importing this associated function
-   |
-LL + use std::io::BufRead::consume;
-   |
 
 error: aborting due to 1 previous error
 

tests/ui/methods/suggest-method-on-call-with-macro-rcvr.stderr

@@ -4,9 +4,10 @@ error[E0425]: cannot find function `len` in this scope
 LL |     let hello = len(vec![]);
    |                 ^^^ not found in this scope
    |
-help: consider importing this associated function
+help: use the `.` operator to call the method `len` on `&Vec<_>`
    |
-LL + use std::iter::ExactSizeIterator::len;
+LL -     let hello = len(vec![]);
+LL +     let hello = vec![].len();
    |
 
 error: aborting due to 1 previous error

tests/ui/resolve/associated-fn-called-as-fn.rs

@@ -1,6 +1,4 @@
 struct S;
-//~^ HELP consider importing one of these associated functions
-//~| HELP consider importing one of these associated functions
 
 impl Foo for S {
     fn parse(s: &str) {