Remove unstable cfg target(...) compact feature from RFC3239

Author: Urgau

Diff for: compiler/rustc_attr/messages.ftl

@@ -107,9 +107,6 @@ attr_unknown_meta_item =
 attr_unknown_version_literal =
     unknown version literal format, assuming it refers to a future version
 
-attr_unstable_cfg_target_compact =
-    compact `cfg(target(..))` is experimental and subject to change
-
 attr_unsupported_literal_cfg_boolean =
     literal in `cfg` predicate value must be a boolean
 attr_unsupported_literal_cfg_string =

Diff for: compiler/rustc_attr/src/builtin.rs

@@ -20,7 +20,6 @@ use rustc_span::hygiene::Transparency;
 use rustc_span::symbol::{Symbol, kw, sym};
 use rustc_span::{DUMMY_SP, Span};
 
-use crate::fluent_generated;
 use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
 
 /// The version placeholder that recently stabilized features contain inside the
@@ -773,39 +772,6 @@ pub fn eval_condition(
 
                     !eval_condition(mi, sess, features, eval)
                 }
-                sym::target => {
-                    if let Some(features) = features
-                        && !features.cfg_target_compact()
-                    {
-                        feature_err(
-                            sess,
-                            sym::cfg_target_compact,
-                            cfg.span,
-                            fluent_generated::attr_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(
-                            &ast::MetaItemInner::MetaItem(mi),
-                            sess,
-                            features,
-                            eval,
-                        )
-                    })
-                }
                 _ => {
                     dcx.emit_err(session_diagnostics::InvalidPredicate {
                         span: cfg.span,

Diff for: compiler/rustc_feature/src/removed.rs

@@ -52,6 +52,9 @@ declare_features! (
     (removed, box_syntax, "1.70.0", Some(49733), Some("replaced with `#[rustc_box]`")),
     /// Allows capturing disjoint fields in a closure/coroutine (RFC 2229).
     (removed, capture_disjoint_fields, "1.49.0", Some(53488), Some("stabilized in Rust 2021")),
+    /// Allows `cfg(target(abi = "..."))`.
+    (removed, cfg_target_compact, "CURRENT_RUSTC_VERSION", Some(96901),
+     Some("removed due to lack of usefulness and users")),
     /// 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")),

Diff for: compiler/rustc_feature/src/unstable.rs

@@ -399,8 +399,6 @@ 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 = "...")`.