Stabilize doc_cfg feature

Author: GuillaumeGomez

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -181,8 +181,6 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
 
                 gate_doc!(
                     "experimental" {
-                        cfg => doc_cfg
-                        auto_cfg => doc_cfg
                         masked => doc_masked
                         notable_trait => doc_notable_trait
                     }

compiler/rustc_error_codes/src/error_codes/E0536.md

@@ -5,7 +5,6 @@ The `not` cfg-predicate was malformed.
 Erroneous code example (using `cargo doc`):
 
 ```ignore, E0536 (only triggers on cargo doc)
-#![feature(doc_cfg)]
 #[doc(cfg(not()))]
 pub fn main() {
 
@@ -15,7 +14,6 @@ pub fn main() {
 The `not` predicate expects one cfg-pattern. Example:
 
 ```
-#![feature(doc_cfg)]
 #[doc(cfg(not(target_os = "linux")))] // ok!
 pub fn main() {
 

compiler/rustc_feature/src/accepted.rs

@@ -187,6 +187,8 @@ declare_features! (
     (accepted, do_not_recommend, "1.85.0", Some(51992)),
     /// Allows `#[doc(alias = "...")]`.
     (accepted, doc_alias, "1.48.0", Some(50146)),
+    /// Allows `#[doc(cfg(...))]`.
+    (accepted, doc_cfg, "1.21.0", Some(43781)),
     /// Allows `..` in tuple (struct) patterns.
     (accepted, dotdot_in_tuple_patterns, "1.14.0", Some(33627)),
     /// Allows `..=` in patterns (RFC 1192).

compiler/rustc_feature/src/unstable.rs

@@ -487,8 +487,6 @@ declare_features! (
     (unstable, derive_from, "1.91.0", Some(144889)),
     /// Allows giving non-const impls custom diagnostic messages if attempted to be used as const
     (unstable, diagnostic_on_const, "CURRENT_RUSTC_VERSION", Some(143874)),
-    /// Allows `#[doc(cfg(...))]`.
-    (unstable, doc_cfg, "1.21.0", Some(43781)),
     /// Allows `#[doc(masked)]`.
     (unstable, doc_masked, "1.21.0", Some(44027)),
     /// Allows features to allow target_feature to better interact with traits.

library/alloc/src/lib.rs

@@ -192,8 +192,6 @@
 #![rustc_preserve_ub_checks]
 // tidy-alphabetical-end
 //
-// Rustdoc features:
-#![feature(doc_cfg)]
 // Technically, this is a bug in rustdoc: rustdoc sees the documentation on `#[lang = slice_alloc]`
 // blocks is for `&[T]`, which also has documentation using this feature in `core`, and gets mad
 // that the feature-gate isn't enabled. Ideally, it wouldn't check for the feature gate for docs

library/core/src/lib.rs

@@ -148,7 +148,6 @@
 #![feature(deprecated_suggestion)]
 #![feature(derive_const)]
 #![feature(diagnostic_on_const)]
-#![feature(doc_cfg)]
 #![feature(doc_notable_trait)]
 #![feature(extern_types)]
 #![feature(f16)]

library/std/src/lib.rs

@@ -278,7 +278,6 @@
 #![feature(core_float_math)]
 #![feature(decl_macro)]
 #![feature(deprecated_suggestion)]
-#![feature(doc_cfg)]
 #![feature(doc_masked)]
 #![feature(doc_notable_trait)]
 #![feature(dropck_eyepatch)]

library/std_detect/src/lib.rs

@@ -15,7 +15,7 @@
 //! * `s390x`: [`is_s390x_feature_detected`]
 
 #![unstable(feature = "stdarch_internal", issue = "none")]
-#![feature(staged_api, cfg_select, doc_cfg, allow_internal_unstable)]
+#![feature(staged_api, cfg_select, allow_internal_unstable)]
 #![deny(rust_2018_idioms)]
 #![allow(clippy::shadow_reuse)]
 #![cfg_attr(test, allow(unused_imports))]

library/stdarch/crates/core_arch/src/lib.rs

@@ -17,7 +17,6 @@
     fmt_helpers_for_derive,
     rustc_attrs,
     staged_api,
-    doc_cfg,
     riscv_target_feature,
     arm_target_feature,
     mips_target_feature,

src/librustdoc/passes/propagate_doc_cfg.rs

@@ -17,11 +17,7 @@ pub(crate) const PROPAGATE_DOC_CFG: Pass = Pass {
 };
 
 pub(crate) fn propagate_doc_cfg(cr: Crate, cx: &mut DocContext<'_>) -> Crate {
-    if cx.tcx.features().doc_cfg() {
-        CfgPropagator { cx, cfg_info: CfgInfo::default() }.fold_crate(cr)
-    } else {
-        cr
-    }
+    CfgPropagator { cx, cfg_info: CfgInfo::default() }.fold_crate(cr)
 }
 
 struct CfgPropagator<'a, 'tcx> {