[WIP] [BROKEN] Move early buffered check-cfg lints to dyn lint diagnostics

Author: fmease

compiler/rustc_attr_parsing/messages.ftl

@@ -217,6 +217,50 @@ attr_parsing_stability_outside_std = stability attributes may not be used outsid
 attr_parsing_suffixed_literal_in_attribute = suffixed literals are not allowed in attributes
     .help = instead of using a suffixed literal (`1u8`, `1.0f32`, etc.), use an unsuffixed version (`1`, `1.0`, etc.)
 
+attr_parsing_unexpected_cfg_add_build_rs_println = or consider adding `{$build_rs_println}` to the top of the `build.rs`
+attr_parsing_unexpected_cfg_add_cargo_feature = consider using a Cargo feature instead
+attr_parsing_unexpected_cfg_add_cargo_toml_lint_cfg = or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:{$cargo_toml_lint_cfg}
+attr_parsing_unexpected_cfg_add_cmdline_arg = to expect this configuration use `{$cmdline_arg}`
+attr_parsing_unexpected_cfg_cargo_update = the {$macro_kind} `{$macro_name}` may come from an old version of the `{$crate_name}` crate, try updating your dependency with `cargo update -p {$crate_name}`
+
+attr_parsing_unexpected_cfg_define_features = consider defining some features in `Cargo.toml`
+attr_parsing_unexpected_cfg_doc_cargo = see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
+attr_parsing_unexpected_cfg_doc_rustc = see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
+
+attr_parsing_unexpected_cfg_from_external_macro_origin = using a cfg inside a {$macro_kind} will use the cfgs from the destination crate and not the ones from the defining crate
+attr_parsing_unexpected_cfg_from_external_macro_refer = try referring to `{$macro_name}` crate for guidance on how handle this unexpected cfg
+attr_parsing_unexpected_cfg_name = unexpected `cfg` condition name: `{$name}`
+attr_parsing_unexpected_cfg_name_expected_names = expected names are: {$possibilities}{$and_more ->
+        [0] {""}
+        *[other] {" "}and {$and_more} more
+    }
+attr_parsing_unexpected_cfg_name_expected_values = expected values for `{$best_match}` are: {$possibilities}
+attr_parsing_unexpected_cfg_name_similar_name = there is a config with a similar name
+attr_parsing_unexpected_cfg_name_similar_name_different_values = there is a config with a similar name and different values
+attr_parsing_unexpected_cfg_name_similar_name_no_value = there is a config with a similar name and no value
+attr_parsing_unexpected_cfg_name_similar_name_value = there is a config with a similar name and value
+attr_parsing_unexpected_cfg_name_version_syntax = there is a similar config predicate: `version("..")`
+attr_parsing_unexpected_cfg_name_with_similar_value = found config with similar value
+
+attr_parsing_unexpected_cfg_value = unexpected `cfg` condition value: {$has_value ->
+        [true] `{$value}`
+        *[false] (none)
+    }
+attr_parsing_unexpected_cfg_value_add_feature = consider adding `{$value}` as a feature in `Cargo.toml`
+attr_parsing_unexpected_cfg_value_expected_values = expected values for `{$name}` are: {$have_none_possibility ->
+        [true] {"(none), "}
+        *[false] {""}
+    }{$possibilities}{$and_more ->
+        [0] {""}
+        *[other] {" "}and {$and_more} more
+    }
+attr_parsing_unexpected_cfg_value_no_expected_value = no expected value for `{$name}`
+attr_parsing_unexpected_cfg_value_no_expected_values = no expected values for `{$name}`
+attr_parsing_unexpected_cfg_value_remove_condition = remove the condition
+attr_parsing_unexpected_cfg_value_remove_value = remove the value
+attr_parsing_unexpected_cfg_value_similar_name = there is a expected value with a similar name
+attr_parsing_unexpected_cfg_value_specify_value = specify a config value
+
 attr_parsing_unknown_meta_item =
     unknown meta item '{$item}'
     .label = expected one of {$expected}

compiler/rustc_attr_parsing/src/attributes/cfg.rs

@@ -16,6 +16,9 @@ use crate::{
     CfgMatchesLintEmitter, fluent_generated, parse_version, session_diagnostics, try_gate_cfg,
 };
 
+// NOTE: Crate-public since it's also used in sibling module `cfg_old`.
+pub(crate) mod check_cfg;
+
 pub const CFG_TEMPLATE: AttributeTemplate = template!(
     List: &["predicate"],
     "https://doc.rust-lang.org/reference/conditional-compilation.html#the-cfg-attribute"
@@ -234,35 +237,37 @@ pub fn eval_config_entry(
                 EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: *span }
             }
         }
-        CfgEntry::NameValue { name, name_span, value, span } => {
+        &CfgEntry::NameValue { name, name_span, value, span } => {
             if let ShouldEmit::ErrorsAndLints = emit_lints {
-                match sess.psess.check_config.expecteds.get(name) {
+                match sess.psess.check_config.expecteds.get(&name) {
                     Some(ExpectedValues::Some(values))
                         if !values.contains(&value.map(|(v, _)| v)) =>
                     {
                         id.emit_span_lint(
                             sess,
                             UNEXPECTED_CFGS,
-                            *span,
-                            BuiltinLintDiag::UnexpectedCfgValue((*name, *name_span), *value),
+                            span,
+                            // TODO: Do it lazily! Somehow pass a TyCtxt if possible
+                            check_cfg::unexpected_cfg_value(sess, None, (name, name_span), value),
                         );
                     }
                     None if sess.psess.check_config.exhaustive_names => {
                         id.emit_span_lint(
                             sess,
                             UNEXPECTED_CFGS,
-                            *span,
-                            BuiltinLintDiag::UnexpectedCfgName((*name, *name_span), *value),
+                            span,
+                            // TODO: Do it lazily! Somehow pass a TyCtxt if possible
+                            check_cfg::unexpected_cfg_name(sess, None, (name, name_span), value),
                         );
                     }
                     _ => { /* not unexpected */ }
                 }
             }
 
-            if sess.psess.config.contains(&(*name, value.map(|(v, _)| v))) {
+            if sess.psess.config.contains(&(name, value.map(|(v, _)| v))) {
                 EvalConfigResult::True
             } else {
-                EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: *span }
+                EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: span }
             }
         }
         CfgEntry::Version(min_version, version_span) => {