Rollup merge of #153138 - mu001999-contrib:print-path-root, r=petrochenkov

Print path root when printing path

Extracted from #152996.

r? petrochenkov

Author: JonathanBrouwer

compiler/rustc_resolve/src/lib.rs

@@ -2504,7 +2504,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
 
 fn names_to_string(names: impl Iterator<Item = Symbol>) -> String {
     let mut result = String::new();
-    for (i, name) in names.filter(|name| *name != kw::PathRoot).enumerate() {
+    for (i, name) in names.enumerate().filter(|(_, name)| *name != kw::PathRoot) {
         if i > 0 {
             result.push_str("::");
         }

tests/ui/resolve/dot-notation-type-namespace-suggest-path-sep.rs

@@ -35,9 +35,9 @@ fn main() {
 macro_rules! Type {
     () => {
         ::std::cell::Cell
-        //~^ ERROR expected value, found struct `std::cell::Cell`
-        //~| ERROR expected value, found struct `std::cell::Cell`
-        //~| ERROR expected value, found struct `std::cell::Cell`
+        //~^ ERROR expected value, found struct `::std::cell::Cell`
+        //~| ERROR expected value, found struct `::std::cell::Cell`
+        //~| ERROR expected value, found struct `::std::cell::Cell`
     };
     (alias) => {
         Alias

tests/ui/resolve/dot-notation-type-namespace-suggest-path-sep.stderr

@@ -70,7 +70,7 @@ LL -     let _ = foo.bar;
 LL +     let _ = foo::bar;
    |
 
-error[E0423]: expected value, found struct `std::cell::Cell`
+error[E0423]: expected value, found struct `::std::cell::Cell`
   --> $DIR/dot-notation-type-namespace-suggest-path-sep.rs:37:9
    |
 LL |         ::std::cell::Cell
@@ -86,7 +86,7 @@ LL -     Type!().get();
 LL +     <Type!()>::get();
    |
 
-error[E0423]: expected value, found struct `std::cell::Cell`
+error[E0423]: expected value, found struct `::std::cell::Cell`
   --> $DIR/dot-notation-type-namespace-suggest-path-sep.rs:37:9
    |
 LL |         ::std::cell::Cell
@@ -166,7 +166,7 @@ LL -         Vec.new
 LL +         Vec::new
    |
 
-error[E0423]: expected value, found struct `std::cell::Cell`
+error[E0423]: expected value, found struct `::std::cell::Cell`
   --> $DIR/dot-notation-type-namespace-suggest-path-sep.rs:37:9
    |
 LL |         ::std::cell::Cell

tests/ui/resolve/issue-100365.rs

@@ -15,8 +15,8 @@ fn main() {
 macro_rules! Trait {
     () => {
         ::std::iter::Iterator
-        //~^ ERROR expected value, found trait `std::iter::Iterator`
-        //~| ERROR expected value, found trait `std::iter::Iterator`
+        //~^ ERROR expected value, found trait `::std::iter::Iterator`
+        //~| ERROR expected value, found trait `::std::iter::Iterator`
     };
 }
 

tests/ui/resolve/issue-100365.stderr

@@ -34,7 +34,7 @@ LL -     let _ = Into::<()>.into;
 LL +     let _ = Into::<()>::into;
    |
 
-error[E0423]: expected value, found trait `std::iter::Iterator`
+error[E0423]: expected value, found trait `::std::iter::Iterator`
   --> $DIR/issue-100365.rs:17:9
    |
 LL |         ::std::iter::Iterator
@@ -45,7 +45,7 @@ LL |     Trait!().map(std::convert::identity); // no `help` here!
    |
    = note: this error originates in the macro `Trait` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error[E0423]: expected value, found trait `std::iter::Iterator`
+error[E0423]: expected value, found trait `::std::iter::Iterator`
   --> $DIR/issue-100365.rs:17:9
    |
 LL |         ::std::iter::Iterator

tests/ui/resolve/resolve-bad-visibility.rs

@@ -2,8 +2,8 @@
 enum E {}
 trait Tr {}
 
-pub(in E) struct S; //~ ERROR expected module, found enum `E`
-pub(in Tr) struct Z; //~ ERROR expected module, found trait `Tr`
+pub(in E) struct S; //~ ERROR expected module, found enum `::E`
+pub(in Tr) struct Z; //~ ERROR expected module, found trait `::Tr`
 pub(in std::vec) struct F; //~ ERROR visibilities can only be restricted to ancestor modules
 pub(in nonexistent) struct G; //~ ERROR cannot find
 pub(in too_soon) struct H; //~ ERROR cannot find

tests/ui/resolve/resolve-bad-visibility.stderr

@@ -1,10 +1,10 @@
-error[E0577]: expected module, found enum `E`
+error[E0577]: expected module, found enum `::E`
   --> $DIR/resolve-bad-visibility.rs:5:8
    |
 LL | pub(in E) struct S;
    |        ^ not a module
 
-error[E0577]: expected module, found trait `Tr`
+error[E0577]: expected module, found trait `::Tr`
   --> $DIR/resolve-bad-visibility.rs:6:8
    |
 LL | pub(in Tr) struct Z;

tests/ui/rfcs/rfc-2126-extern-absolute-paths/single-segment.rs

@@ -6,6 +6,6 @@ use crate; //~ ERROR imports need to be explicitly named
 use *; //~ ERROR cannot glob-import all possible crates
 
 fn main() {
-    let s = ::xcrate; //~ ERROR expected value, found crate `xcrate`
+    let s = ::xcrate; //~ ERROR expected value, found crate `::xcrate`
                       //~^ NOTE not a value
 }

tests/ui/rfcs/rfc-2126-extern-absolute-paths/single-segment.stderr

@@ -15,7 +15,7 @@ error: cannot glob-import all possible crates
 LL | use *;
    |     ^
 
-error[E0423]: expected value, found crate `xcrate`
+error[E0423]: expected value, found crate `::xcrate`
   --> $DIR/single-segment.rs:9:13
    |
 LL |     let s = ::xcrate;