Rollup merge of rust-lang#40027 - cramertj:stabilize_static_recursion…

…, r=nrc

Stabilize static_recursion

Fix rust-lang#29719.

src/librustc_passes/static_recursion.rs

@@ -18,7 +18,6 @@ use rustc::hir::def::{Def, CtorKind};
 use rustc::util::nodemap::{NodeMap, NodeSet};
 
 use syntax::ast;
-use syntax::feature_gate::{GateIssue, emit_feature_err};
 use syntax_pos::Span;
 use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
 use rustc::hir;
@@ -43,7 +42,7 @@ impl<'a, 'hir: 'a> Visitor<'hir> for CheckCrateVisitor<'a, 'hir> {
         match it.node {
             hir::ItemStatic(..) |
             hir::ItemConst(..) => {
-                let mut recursion_visitor = CheckItemRecursionVisitor::new(self, &it.span);
+                let mut recursion_visitor = CheckItemRecursionVisitor::new(self);
                 recursion_visitor.visit_item(it);
             }
             hir::ItemEnum(ref enum_def, ref generics) => {
@@ -52,8 +51,7 @@ impl<'a, 'hir: 'a> Visitor<'hir> for CheckCrateVisitor<'a, 'hir> {
                 // less redundant output.
                 for variant in &enum_def.variants {
                     if let Some(_) = variant.node.disr_expr {
-                        let mut recursion_visitor = CheckItemRecursionVisitor::new(self,
-                                                                                   &variant.span);
+                        let mut recursion_visitor = CheckItemRecursionVisitor::new(self);
                         recursion_visitor.populate_enum_discriminants(enum_def);
                         recursion_visitor.visit_variant(variant, generics, it.id);
                     }
@@ -68,7 +66,7 @@ impl<'a, 'hir: 'a> Visitor<'hir> for CheckCrateVisitor<'a, 'hir> {
         match ti.node {
             hir::TraitItemKind::Const(_, ref default) => {
                 if let Some(_) = *default {
-                    let mut recursion_visitor = CheckItemRecursionVisitor::new(self, &ti.span);
+                    let mut recursion_visitor = CheckItemRecursionVisitor::new(self);
                     recursion_visitor.visit_trait_item(ti);
                 }
             }
@@ -80,7 +78,7 @@ impl<'a, 'hir: 'a> Visitor<'hir> for CheckCrateVisitor<'a, 'hir> {
     fn visit_impl_item(&mut self, ii: &'hir hir::ImplItem) {
         match ii.node {
             hir::ImplItemKind::Const(..) => {
-                let mut recursion_visitor = CheckItemRecursionVisitor::new(self, &ii.span);
+                let mut recursion_visitor = CheckItemRecursionVisitor::new(self);
                 recursion_visitor.visit_impl_item(ii);
             }
             _ => {}
@@ -105,7 +103,6 @@ pub fn check_crate<'hir>(sess: &Session, hir_map: &hir_map::Map<'hir>) -> Compil
 }
 
 struct CheckItemRecursionVisitor<'a, 'b: 'a, 'hir: 'b> {
-    root_span: &'b Span,
     sess: &'b Session,
     hir_map: &'b hir_map::Map<'hir>,
     discriminant_map: &'a mut NodeMap<Option<hir::BodyId>>,
@@ -114,9 +111,8 @@ struct CheckItemRecursionVisitor<'a, 'b: 'a, 'hir: 'b> {
 }
 
 impl<'a, 'b: 'a, 'hir: 'b> CheckItemRecursionVisitor<'a, 'b, 'hir> {
-    fn new(v: &'a mut CheckCrateVisitor<'b, 'hir>, span: &'b Span) -> Self {
+    fn new(v: &'a mut CheckCrateVisitor<'b, 'hir>) -> Self {
         CheckItemRecursionVisitor {
-            root_span: span,
             sess: v.sess,
             hir_map: v.hir_map,
             discriminant_map: &mut v.discriminant_map,
@@ -143,15 +139,7 @@ impl<'a, 'b: 'a, 'hir: 'b> CheckItemRecursionVisitor<'a, 'b, 'hir> {
                     false
                 }
             });
-            if any_static {
-                if !self.sess.features.borrow().static_recursion {
-                    emit_feature_err(&self.sess.parse_sess,
-                                     "static_recursion",
-                                     *self.root_span,
-                                     GateIssue::Language,
-                                     "recursive static");
-                }
-            } else {
+            if !any_static {
                 struct_span_err!(self.sess, span, E0265, "recursive constant")
                     .span_label(span, &format!("recursion not allowed in constant"))
                     .emit();

src/libsyntax/feature_gate.rs

@@ -200,9 +200,6 @@ declare_features! (
     // rustc internal
     (active, prelude_import, "1.2.0", None),
 
-    // Allows the definition recursive static items.
-    (active, static_recursion, "1.3.0", Some(29719)),
-
     // Allows default type parameters to influence type inference.
     (active, default_type_parameter_fallback, "1.3.0", Some(27336)),
 
@@ -391,6 +388,8 @@ declare_features! (
     (accepted, static_in_const, "1.17.0", Some(35897)),
     // Allows field shorthands (`x` meaning `x: x`) in struct literal expressions.
     (accepted, field_init_shorthand, "1.17.0", Some(37340)),
+    // Allows the definition recursive static items.
+    (accepted, static_recursion, "1.17.0", Some(29719)),
 );
 // If you change this, please modify src/doc/unstable-book as well. You must
 // move that documentation into the relevant place in the other docs, and

src/test/compile-fail/issue-3008-2.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(static_recursion)]
-
 enum foo { foo_(bar) }
 struct bar { x: bar }
 //~^ ERROR E0072

src/test/run-pass/issue-2063-resource.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(static_recursion)]
-
 // test that autoderef of a type like this does not
 // cause compiler to loop.  Note that no instances
 // of such a type could ever be constructed.

src/test/run-pass/issue-2063.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(static_recursion)]
-
 // test that autoderef of a type like this does not
 // cause compiler to loop.  Note that no instances
 // of such a type could ever be constructed.

src/test/run-pass/static-recursive.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(static_recursion)]
-
 static mut S: *const u8 = unsafe { &S as *const *const u8 as *const u8 };
 
 struct StaticDoubleLinked {