Remove unstable cfg target(...) compact feature

compiler/rustc_attr_parsing/messages.ftl

@@ -115,9 +115,6 @@ attr_parsing_unrecognized_repr_hint =
     unrecognized representation hint
     .help = valid reprs are `Rust` (default), `C`, `align`, `packed`, `transparent`, `simd`, `i8`, `u8`, `i16`, `u16`, `i32`, `u32`, `i64`, `u64`, `i128`, `u128`, `isize`, `usize`
 
-attr_parsing_unstable_cfg_target_compact =
-    compact `cfg(target(..))` is experimental and subject to change
-
 attr_parsing_unsupported_literal_cfg_boolean =
     literal in `cfg` predicate value must be a boolean
 attr_parsing_unsupported_literal_cfg_string =

compiler/rustc_attr_parsing/src/attributes/cfg.rs

@@ -9,8 +9,8 @@ use rustc_session::lint::{BuiltinLintDiag, Lint};
 use rustc_session::parse::feature_err;
 use rustc_span::{Span, Symbol, sym};
 
+use crate::parse_version;
 use crate::session_diagnostics::{self, UnsupportedLiteralReason};
-use crate::{fluent_generated, parse_version};
 
 /// Emitter of a builtin lint from `cfg_matches`.
 ///
@@ -183,34 +183,6 @@ pub fn eval_condition(
 
                     !eval_condition(mi, sess, features, eval)
                 }
-                Some(sym::target) => {
-                    if let Some(features) = features
-                        && !features.cfg_target_compact()
-                    {
-                        feature_err(
-                            sess,
-                            sym::cfg_target_compact,
-                            cfg.span,
-                            fluent_generated::attr_parsing_unstable_cfg_target_compact,
-                        )
-                        .emit();
-                    }
-
-                    mis.iter().fold(true, |res, mi| {
-                        let Some(mut mi) = mi.meta_item().cloned() else {
-                            dcx.emit_err(session_diagnostics::CfgPredicateIdentifier {
-                                span: mi.span(),
-                            });
-                            return false;
-                        };
-
-                        if let [seg, ..] = &mut mi.path.segments[..] {
-                            seg.ident.name = Symbol::intern(&format!("target_{}", seg.ident.name));
-                        }
-
-                        res & eval_condition(&MetaItemInner::MetaItem(mi), sess, features, eval)
-                    })
-                }
                 _ => {
                     dcx.emit_err(session_diagnostics::InvalidPredicate {
                         span: cfg.span,

compiler/rustc_feature/src/removed.rs

@@ -65,6 +65,9 @@ declare_features! (
     (removed, box_syntax, "1.70.0", Some(49733), Some("replaced with `#[rustc_box]`"), 108471),
     /// Allows capturing disjoint fields in a closure/coroutine (RFC 2229).
     (removed, capture_disjoint_fields, "1.69.0", Some(53488), Some("stabilized in Rust 2021"), 108550),
+    /// Allows `cfg(target(abi = "..."))`.
+    (removed, cfg_target_compact, "CURRENT_RUSTC_VERSION", Some(96901),
+     Some("removed due to lack of usefulness and users"), 130780),
     /// Allows comparing raw pointers during const eval.
     (removed, const_compare_raw_pointers, "1.46.0", Some(53020),
      Some("cannot be allowed in const eval in any meaningful way"), 73398),

compiler/rustc_feature/src/unstable.rs

@@ -409,8 +409,6 @@ declare_features! (
     (unstable, cfg_sanitize, "1.41.0", Some(39699)),
     /// Allows `cfg(sanitizer_cfi_generalize_pointers)` and `cfg(sanitizer_cfi_normalize_integers)`.
     (unstable, cfg_sanitizer_cfi, "1.77.0", Some(89653)),
-    /// Allows `cfg(target(abi = "..."))`.
-    (unstable, cfg_target_compact, "1.63.0", Some(96901)),
     /// Allows `cfg(target_has_atomic_load_store = "...")`.
     (unstable, cfg_target_has_atomic, "1.60.0", Some(94039)),
     /// Allows `cfg(target_has_atomic_equal_alignment = "...")`.