Rollup merge of #56072 - da-x:stabilize-literal-matcher, r=petrochenkov

Stabilize macro_literal_matcher

This followed FCP in #35625.

Closes #35625

7 files changed, 15 insertions, 73 deletions

diff --git a/src/doc/unstable-book/src/language-features/macro-literal-matcher.md b/src/doc/unstable-book/src/language-features/macro-literal-matcher.md
deleted file mode 100644
index 870158200de..00000000000
--- a/src/doc/unstable-book/src/language-features/macro-literal-matcher.md
+++ /dev/null
@@ -1,17 +0,0 @@
-# `macro_literal_matcher`
-
-The tracking issue for this feature is: [#35625]
-
-The RFC is: [rfc#1576].
-
-With this feature gate enabled, the [list of designators] gains one more entry:
-
-* `literal`: a literal. Examples: 2, "string", 'c'
-
-A `literal` may be followed by anything, similarly to the `ident` specifier.
-
-[rfc#1576]: http://rust-lang.github.io/rfcs/1576-macros-literal-matcher.html
-[#35625]: https://github.com/rust-lang/rust/issues/35625
-[list of designators]: ../reference/macros-by-example.html
-
-------------------------
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 6bba891278a..d526e464ba4 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -19,7 +19,7 @@ use ext::tt::macro_parser::{MatchedSeq, MatchedNonterminal};
 use ext::tt::macro_parser::{parse, parse_failure_msg};
 use ext::tt::quoted;
 use ext::tt::transcribe::transcribe;
-use feature_gate::{self, emit_feature_err, Features, GateIssue};
+use feature_gate::Features;
 use parse::{Directory, ParseSess};
 use parse::parser::Parser;
 use parse::token::{self, NtTT};
@@ -1027,26 +1027,21 @@ fn has_legal_fragment_specifier(sess: &ParseSess,
     Ok(())
 }
 
-fn is_legal_fragment_specifier(sess: &ParseSess,
-                               features: &Features,
-                               attrs: &[ast::Attribute],
+fn is_legal_fragment_specifier(_sess: &ParseSess,
+                               _features: &Features,
+                               _attrs: &[ast::Attribute],
                                frag_name: &str,
-                               frag_span: Span) -> bool {
+                               _frag_span: Span) -> bool {
+    /*
+     * If new fragment specifiers are invented in nightly, `_sess`,
+     * `_features`, `_attrs`, and `_frag_span` will be useful here
+     * for checking against feature gates. See past versions of
+     * this function.
+     */
     match frag_name {
         "item" | "block" | "stmt" | "expr" | "pat" | "lifetime" |
-        "path" | "ty" | "ident" | "meta" | "tt" | "vis" | "" => true,
-        "literal" => {
-            if !features.macro_literal_matcher &&
-               !attr::contains_name(attrs, "allow_internal_unstable") {
-                let explain = feature_gate::EXPLAIN_LITERAL_MATCHER;
-                emit_feature_err(sess,
-                                 "macro_literal_matcher",
-                                 frag_span,
-                                 GateIssue::Language,
-                                 explain);
-            }
-            true
-        },
+        "path" | "ty" | "ident" | "meta" | "tt" | "vis" | "literal" |
+        "" => true,
         _ => false,
     }
 }
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 2f5db9bd081..73567765a04 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -436,9 +436,6 @@ declare_features! (
     // Allows irrefutable patterns in if-let and while-let statements (RFC 2086)
     (active, irrefutable_let_patterns, "1.27.0", Some(44495), None),
 
-    // Allows use of the :literal macro fragment specifier (RFC 1576)
-    (active, macro_literal_matcher, "1.27.0", Some(35625), None),
-
     // inconsistent bounds in where clauses
     (active, trivial_bounds, "1.28.0", Some(48214), None),
 
@@ -690,6 +687,8 @@ declare_features! (
     (accepted, impl_header_lifetime_elision, "1.31.0", Some(15872), None),
     // `extern crate foo as bar;` puts `bar` into extern prelude.
     (accepted, extern_crate_item_prelude, "1.31.0", Some(55599), None),
+    // Allows use of the :literal macro fragment specifier (RFC 1576)
+    (accepted, macro_literal_matcher, "1.31.0", Some(35625), None),
 );
 
 // If you change this, please modify src/doc/unstable-book as well. You must
@@ -1425,9 +1424,6 @@ pub const EXPLAIN_DEPR_CUSTOM_DERIVE: &'static str =
 pub const EXPLAIN_DERIVE_UNDERSCORE: &'static str =
     "attributes of the form `#[derive_*]` are reserved for the compiler";
 
-pub const EXPLAIN_LITERAL_MATCHER: &'static str =
-    ":literal fragment specifier is experimental and subject to change";
-
 pub const EXPLAIN_UNSIZED_TUPLE_COERCION: &'static str =
     "unsized tuple coercion is not stable enough for use and is subject to change";
 
diff --git a/src/test/run-pass/issues/issue-52169.rs b/src/test/run-pass/issues/issue-52169.rs
index 19c0f51d235..c4ed534cc20 100644
--- a/src/test/run-pass/issues/issue-52169.rs
+++ b/src/test/run-pass/issues/issue-52169.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 // run-pass
-#![feature(macro_literal_matcher)]
 
 macro_rules! a {
     ($i:literal) => { "right" };
diff --git a/src/test/run-pass/macros/macro-literal.rs b/src/test/run-pass/macros/macro-literal.rs
index ecbb47757d1..de268e3388a 100644
--- a/src/test/run-pass/macros/macro-literal.rs
+++ b/src/test/run-pass/macros/macro-literal.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 // run-pass
-#![feature(macro_literal_matcher)]
 
 macro_rules! mtester {
     ($l:literal) => {
diff --git a/src/test/ui/feature-gates/feature-gate-macro-literal-matcher.rs b/src/test/ui/feature-gates/feature-gate-macro-literal-matcher.rs
deleted file mode 100644
index db5cca193ab..00000000000
--- a/src/test/ui/feature-gates/feature-gate-macro-literal-matcher.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-// Test that the :lifetime macro fragment cannot be used when macro_lifetime_matcher
-// feature gate is not used.
-
-macro_rules! m { ($lt:literal) => {} }
-//~^ ERROR :literal fragment specifier is experimental and subject to change
-
-fn main() {
-    m!("some string literal");
-}
diff --git a/src/test/ui/feature-gates/feature-gate-macro-literal-matcher.stderr b/src/test/ui/feature-gates/feature-gate-macro-literal-matcher.stderr
deleted file mode 100644
index f714b916966..00000000000
--- a/src/test/ui/feature-gates/feature-gate-macro-literal-matcher.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-error[E0658]: :literal fragment specifier is experimental and subject to change (see issue #35625)
-  --> $DIR/feature-gate-macro-literal-matcher.rs:14:19
-   |
-LL | macro_rules! m { ($lt:literal) => {} }
-   |                   ^^^^^^^^^^^
-   |
-   = help: add #![feature(macro_literal_matcher)] to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.