Improve check-cfg diagnostics (part 1)

12 files changed, 40 insertions, 38 deletions

diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs
index 70426d86075..5d32080a998 100644
--- a/compiler/rustc_attr/src/builtin.rs
+++ b/compiler/rustc_attr/src/builtin.rs
@@ -591,7 +591,7 @@ pub fn cfg_matches(
                     "unexpected `cfg` condition value",
                     BuiltinLintDiagnostics::UnexpectedCfg(
                         (cfg.name, cfg.name_span),
-                        cfg.value_span.map(|vs| (cfg.value.unwrap(), vs)),
+                        cfg.value.map(|v| (v, cfg.value_span.unwrap())),
                     ),
                 );
             }
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index f53a7bb0c19..63c25d8f030 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -773,7 +773,7 @@ pub trait LintContext: Sized {
 
                     // Suggest the most probable if we found one
                     if let Some(best_match) = find_best_match_for_name(&possibilities, name, None) {
-                        db.span_suggestion(name_span, "did you mean", best_match, Applicability::MaybeIncorrect);
+                        db.span_suggestion(name_span, "there is an config with a similar name", best_match, Applicability::MaybeIncorrect);
                     }
                 },
                 BuiltinLintDiagnostics::UnexpectedCfg((name, name_span), Some((value, value_span))) => {
@@ -794,19 +794,19 @@ pub trait LintContext: Sized {
                             let mut possibilities = possibilities.iter().map(Symbol::as_str).collect::<Vec<_>>();
                             possibilities.sort();
 
-                            let possibilities = possibilities.join(", ");
-                            db.note(format!("expected values for `{name}` are: {possibilities}"));
+                            let possibilities = possibilities.join("`, `");
+                            let none = if have_none_possibility { "(none), " } else { "" };
+
+                            db.note(format!("expected values for `{name}` are: {none}`{possibilities}`"));
                         }
 
                         // Suggest the most probable if we found one
                         if let Some(best_match) = find_best_match_for_name(&possibilities, value, None) {
-                            db.span_suggestion(value_span, "did you mean", format!("\"{best_match}\""), Applicability::MaybeIncorrect);
+                            db.span_suggestion(value_span, "there is an expected value with a similar name", format!("\"{best_match}\""), Applicability::MaybeIncorrect);
                         }
-                    } else {
+                    } else if have_none_possibility {
                         db.note(format!("no expected value for `{name}`"));
-                        if name != sym::feature {
-                            db.span_suggestion(name_span.shrink_to_hi().to(value_span), "remove the value", "", Applicability::MaybeIncorrect);
-                        }
+                        db.span_suggestion(name_span.shrink_to_hi().to(value_span), "remove the value", "", Applicability::MaybeIncorrect);
                     }
                 },
                 BuiltinLintDiagnostics::DeprecatedWhereclauseLocation(new_span, suggestion) => {
diff --git a/tests/rustdoc-ui/check-cfg/check-cfg.stderr b/tests/rustdoc-ui/check-cfg/check-cfg.stderr
index 1db8e1d91c2..03fb6f96fb5 100644
--- a/tests/rustdoc-ui/check-cfg/check-cfg.stderr
+++ b/tests/rustdoc-ui/check-cfg/check-cfg.stderr
@@ -2,7 +2,7 @@ warning: unexpected `cfg` condition name
   --> $DIR/check-cfg.rs:5:7
    |
 LL | #[cfg(uniz)]
-   |       ^^^^ help: did you mean: `unix`
+   |       ^^^^ help: there is a config with a similar name: `unix`
    |
    = note: `#[warn(unexpected_cfgs)]` on by default
 
diff --git a/tests/rustdoc-ui/doctest/check-cfg-test.stderr b/tests/rustdoc-ui/doctest/check-cfg-test.stderr
index 9770be2f191..f84543c2072 100644
--- a/tests/rustdoc-ui/doctest/check-cfg-test.stderr
+++ b/tests/rustdoc-ui/doctest/check-cfg-test.stderr
@@ -4,7 +4,7 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(feature = "invalid")]
    |       ^^^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: test
+   = note: expected values for `feature` are: `test`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/check-cfg/compact-values.stderr b/tests/ui/check-cfg/compact-values.stderr
index 5ca4d3b3de7..70a967c0e5f 100644
--- a/tests/ui/check-cfg/compact-values.stderr
+++ b/tests/ui/check-cfg/compact-values.stderr
@@ -4,7 +4,7 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(target(os = "linux", arch = "X"))]
    |                            ^^^^^^^^^^
    |
-   = note: expected values for `target_arch` are: aarch64, arm, avr, bpf, hexagon, loongarch64, m68k, mips, mips64, msp430, nvptx64, powerpc, powerpc64, riscv32, riscv64, s390x, sparc, sparc64, wasm32, wasm64, x86, x86_64
+   = note: expected values for `target_arch` are: `aarch64`, `arm`, `avr`, `bpf`, `hexagon`, `loongarch64`, `m68k`, `mips`, `mips64`, `msp430`, `nvptx64`, `powerpc`, `powerpc64`, `riscv32`, `riscv64`, `s390x`, `sparc`, `sparc64`, `wasm32`, `wasm64`, `x86`, `x86_64`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/check-cfg/invalid-cfg-name.stderr b/tests/ui/check-cfg/invalid-cfg-name.stderr
index 2bd1821c942..01ee4f209f1 100644
--- a/tests/ui/check-cfg/invalid-cfg-name.stderr
+++ b/tests/ui/check-cfg/invalid-cfg-name.stderr
@@ -2,7 +2,7 @@ warning: unexpected `cfg` condition name
   --> $DIR/invalid-cfg-name.rs:7:7
    |
 LL | #[cfg(widnows)]
-   |       ^^^^^^^ help: did you mean: `windows`
+   |       ^^^^^^^ help: there is an config with a similar name: `windows`
    |
    = note: `#[warn(unexpected_cfgs)]` on by default
 
diff --git a/tests/ui/check-cfg/invalid-cfg-value.stderr b/tests/ui/check-cfg/invalid-cfg-value.stderr
index 83383ea61a4..0ef8a06dc92 100644
--- a/tests/ui/check-cfg/invalid-cfg-value.stderr
+++ b/tests/ui/check-cfg/invalid-cfg-value.stderr
@@ -4,9 +4,9 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(feature = "sedre")]
    |       ^^^^^^^^^^-------
    |                 |
-   |                 help: did you mean: `"serde"`
+   |                 help: there is an expected value with a similar name: `"serde"`
    |
-   = note: expected values for `feature` are: full, serde
+   = note: expected values for `feature` are: `full`, `serde`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition value
@@ -15,7 +15,7 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(feature = "rand")]
    |       ^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: full, serde
+   = note: expected values for `feature` are: `full`, `serde`
 
 warning: unexpected condition value `rand` for condition name `feature`
    |
diff --git a/tests/ui/check-cfg/mix.stderr b/tests/ui/check-cfg/mix.stderr
index 9cf887ec788..e3738af13ff 100644
--- a/tests/ui/check-cfg/mix.stderr
+++ b/tests/ui/check-cfg/mix.stderr
@@ -2,7 +2,7 @@ warning: unexpected `cfg` condition name
   --> $DIR/mix.rs:11:7
    |
 LL | #[cfg(widnows)]
-   |       ^^^^^^^ help: did you mean: `windows`
+   |       ^^^^^^^ help: there is an config with a similar name: `windows`
    |
    = note: `#[warn(unexpected_cfgs)]` on by default
 
@@ -12,7 +12,7 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(feature = "bar")]
    |       ^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition value
   --> $DIR/mix.rs:22:7
@@ -20,7 +20,7 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(feature = "zebra")]
    |       ^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition name
   --> $DIR/mix.rs:26:12
@@ -40,7 +40,7 @@ warning: unexpected `cfg` condition name
   --> $DIR/mix.rs:35:10
    |
 LL |     cfg!(widnows);
-   |          ^^^^^^^ help: did you mean: `windows`
+   |          ^^^^^^^ help: there is an config with a similar name: `windows`
 
 warning: unexpected `cfg` condition value
   --> $DIR/mix.rs:38:10
@@ -48,7 +48,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(feature = "bar");
    |          ^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition value
   --> $DIR/mix.rs:40:10
@@ -56,7 +56,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(feature = "zebra");
    |          ^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition name
   --> $DIR/mix.rs:42:10
@@ -82,7 +82,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(any(feature = "bad", windows));
    |              ^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition name
   --> $DIR/mix.rs:50:23
@@ -126,7 +126,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(any(unix, feature = "zebra"));
    |                    ^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition name
   --> $DIR/mix.rs:62:14
@@ -140,7 +140,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(any(xxx, feature = "zebra"));
    |                   ^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition name
   --> $DIR/mix.rs:65:14
@@ -160,7 +160,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
    |              ^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition value
   --> $DIR/mix.rs:68:33
@@ -168,7 +168,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
    |                                 ^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: unexpected `cfg` condition value
   --> $DIR/mix.rs:68:52
@@ -176,7 +176,7 @@ warning: unexpected `cfg` condition value
 LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
    |                                                    ^^^^^^^^^^^^^^^^^
    |
-   = note: expected values for `feature` are: foo
+   = note: expected values for `feature` are: `foo`
 
 warning: 27 warnings emitted
 
diff --git a/tests/ui/check-cfg/no-values.stderr b/tests/ui/check-cfg/no-values.stderr
index 8c926d187fe..ffa87dc58f2 100644
--- a/tests/ui/check-cfg/no-values.stderr
+++ b/tests/ui/check-cfg/no-values.stderr
@@ -2,7 +2,9 @@ warning: unexpected `cfg` condition value
   --> $DIR/no-values.rs:6:7
    |
 LL | #[cfg(feature = "foo")]
-   |       ^^^^^^^^^^^^^^^
+   |       ^^^^^^^--------
+   |              |
+   |              help: remove the value
    |
    = note: no expected value for `feature`
    = note: `#[warn(unexpected_cfgs)]` on by default
diff --git a/tests/ui/check-cfg/values-target-json.stderr b/tests/ui/check-cfg/values-target-json.stderr
index b58d2970773..8500fc08805 100644
--- a/tests/ui/check-cfg/values-target-json.stderr
+++ b/tests/ui/check-cfg/values-target-json.stderr
@@ -4,9 +4,9 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(target_os = "linuz")]
    |       ^^^^^^^^^^^^-------
    |                   |
-   |                   help: did you mean: `"linux"`
+   |                   help: there is an expected value with a similar name: `"linux"`
    |
-   = note: expected values for `target_os` are: aix, android, cuda, dragonfly, emscripten, ericos, espidf, freebsd, fuchsia, haiku, hermit, horizon, illumos, ios, l4re, linux, macos, netbsd, none, nto, openbsd, psp, redox, solaris, solid_asp3, tvos, uefi, unknown, vita, vxworks, wasi, watchos, windows, xous
+   = note: expected values for `target_os` are: `aix`, `android`, `cuda`, `dragonfly`, `emscripten`, `ericos`, `espidf`, `freebsd`, `fuchsia`, `haiku`, `hermit`, `horizon`, `illumos`, `ios`, `l4re`, `linux`, `macos`, `netbsd`, `none`, `nto`, `openbsd`, `psp`, `redox`, `solaris`, `solid_asp3`, `tvos`, `uefi`, `unknown`, `vita`, `vxworks`, `wasi`, `watchos`, `windows`, `xous`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: 1 warning emitted
diff --git a/tests/ui/check-cfg/well-known-names.stderr b/tests/ui/check-cfg/well-known-names.stderr
index bdbe4d29d30..987339a222a 100644
--- a/tests/ui/check-cfg/well-known-names.stderr
+++ b/tests/ui/check-cfg/well-known-names.stderr
@@ -4,7 +4,7 @@ warning: unexpected `cfg` condition name
 LL | #[cfg(target_oz = "linux")]
    |       ---------^^^^^^^^^^
    |       |
-   |       help: did you mean: `target_os`
+   |       help: there is an config with a similar name: `target_os`
    |
    = note: `#[warn(unexpected_cfgs)]` on by default
 
@@ -14,13 +14,13 @@ warning: unexpected `cfg` condition name
 LL | #[cfg(features = "foo")]
    |       --------^^^^^^^^
    |       |
-   |       help: did you mean: `feature`
+   |       help: there is an config with a similar name: `feature`
 
 warning: unexpected `cfg` condition name
   --> $DIR/well-known-names.rs:20:7
    |
 LL | #[cfg(uniw)]
-   |       ^^^^ help: did you mean: `unix`
+   |       ^^^^ help: there is an config with a similar name: `unix`
 
 warning: 3 warnings emitted
 
diff --git a/tests/ui/check-cfg/well-known-values.stderr b/tests/ui/check-cfg/well-known-values.stderr
index 69d799783a9..4bd8e6ae09f 100644
--- a/tests/ui/check-cfg/well-known-values.stderr
+++ b/tests/ui/check-cfg/well-known-values.stderr
@@ -4,9 +4,9 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(target_os = "linuz")]
    |       ^^^^^^^^^^^^-------
    |                   |
-   |                   help: did you mean: `"linux"`
+   |                   help: there is an expected value with a similar name: `"linux"`
    |
-   = note: expected values for `target_os` are: aix, android, cuda, dragonfly, emscripten, espidf, freebsd, fuchsia, haiku, hermit, horizon, illumos, ios, l4re, linux, macos, netbsd, none, nto, openbsd, psp, redox, solaris, solid_asp3, tvos, uefi, unknown, vita, vxworks, wasi, watchos, windows, xous
+   = note: expected values for `target_os` are: `aix`, `android`, `cuda`, `dragonfly`, `emscripten`, `espidf`, `freebsd`, `fuchsia`, `haiku`, `hermit`, `horizon`, `illumos`, `ios`, `l4re`, `linux`, `macos`, `netbsd`, `none`, `nto`, `openbsd`, `psp`, `redox`, `solaris`, `solid_asp3`, `tvos`, `uefi`, `unknown`, `vita`, `vxworks`, `wasi`, `watchos`, `windows`, `xous`
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition value
@@ -15,9 +15,9 @@ warning: unexpected `cfg` condition value
 LL | #[cfg(target_has_atomic = "0")]
    |       ^^^^^^^^^^^^^^^^^^^^---
    |                           |
-   |                           help: did you mean: `"8"`
+   |                           help: there is an expected value with a similar name: `"8"`
    |
-   = note: expected values for `target_has_atomic` are: 128, 16, 32, 64, 8, ptr
+   = note: expected values for `target_has_atomic` are: (none), `128`, `16`, `32`, `64`, `8`, `ptr`
 
 warning: unexpected `cfg` condition value
   --> $DIR/well-known-values.rs:21:7