Rollup merge of #40027 - cramertj:stabilize_static_recursion, r=nrc

Stabilize static_recursion

Fix #29719.

8 files changed, 8 insertions, 94 deletions

diff --git a/src/librustc_passes/static_recursion.rs b/src/librustc_passes/static_recursion.rs
index 1ef8a5b0080..fc05471ead3 100644
--- a/src/librustc_passes/static_recursion.rs
+++ b/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();
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index b66b08f8cd8..c2b72edb66c 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/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
diff --git a/src/test/compile-fail/feature-gate-static_recursion.rs b/src/test/compile-fail/feature-gate-static_recursion.rs
deleted file mode 100644
index bd20c891d8e..00000000000
--- a/src/test/compile-fail/feature-gate-static_recursion.rs
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-static mut S: *const u8 = unsafe { &S as *const *const u8 as *const u8 };
-//~^ ERROR recursive static (see issue #29719)
-
-struct StaticDoubleLinked {
-    prev: &'static StaticDoubleLinked,
-    next: &'static StaticDoubleLinked,
-    data: i32,
-    head: bool,
-}
-
-static L1: StaticDoubleLinked = StaticDoubleLinked{prev: &L3, next: &L2, data: 1, head: true};
-//~^ ERROR recursive static (see issue #29719)
-//~^^ ERROR recursive static (see issue #29719)
-//~^^^ ERROR recursive static (see issue #29719)
-static L2: StaticDoubleLinked = StaticDoubleLinked{prev: &L1, next: &L3, data: 2, head: false};
-static L3: StaticDoubleLinked = StaticDoubleLinked{prev: &L2, next: &L1, data: 3, head: false};
-
-
-pub fn main() {
-    unsafe { assert_eq!(S, *(S as *const *const u8)); }
-
-    let mut test_vec = Vec::new();
-    let mut cur = &L1;
-    loop {
-        test_vec.push(cur.data);
-        cur = cur.next;
-        if cur.head { break }
-    }
-    assert_eq!(&test_vec, &[1,2,3]);
-
-    let mut test_vec = Vec::new();
-    let mut cur = &L1;
-    loop {
-        cur = cur.prev;
-        test_vec.push(cur.data);
-        if cur.head { break }
-    }
-    assert_eq!(&test_vec, &[3,2,1]);
-}
diff --git a/src/test/compile-fail/issue-3008-2.rs b/src/test/compile-fail/issue-3008-2.rs
index 38b5fcbb3db..3bc8413cbca 100644
--- a/src/test/compile-fail/issue-3008-2.rs
+++ b/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
diff --git a/src/test/compile-fail/static-recursion-gate.rs b/src/test/compile-fail/static-recursion-gate.rs
deleted file mode 100644
index 29b5689fa93..00000000000
--- a/src/test/compile-fail/static-recursion-gate.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-static mut S: *const u8 = unsafe { &S as *const *const u8 as *const u8 };
-//~^ ERROR recursive static
-
-pub fn main() {
-    unsafe { assert_eq!(S, *(S as *const *const u8)); }
-}
diff --git a/src/test/run-pass/issue-2063-resource.rs b/src/test/run-pass/issue-2063-resource.rs
index aa9a7afc37f..c3a0dc67e83 100644
--- a/src/test/run-pass/issue-2063-resource.rs
+++ b/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.
diff --git a/src/test/run-pass/issue-2063.rs b/src/test/run-pass/issue-2063.rs
index 48da7ecc508..5be4f8e8e73 100644
--- a/src/test/run-pass/issue-2063.rs
+++ b/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.
diff --git a/src/test/run-pass/static-recursive.rs b/src/test/run-pass/static-recursive.rs
index f3db102ea5a..4a6ba984eef 100644
--- a/src/test/run-pass/static-recursive.rs
+++ b/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 {