missing_fragment_specifier -> hard error

Author: Centril

src/doc/rustc/src/lints/listing/deny-by-default.md

@@ -91,16 +91,6 @@ The legacy_directory_ownership warning is issued when
 The warning can be fixed by renaming the parent module to "mod.rs" and moving
 it into its own directory if appropriate.
 
-
-## missing-fragment-specifier
-
-The missing_fragment_specifier warning is issued when an unused pattern in a
-`macro_rules!` macro definition has a meta-variable (e.g. `$e`) that is not
-followed by a fragment specifier (e.g. `:expr`).
-
-This warning can always be fixed by removing the unused pattern in the
-`macro_rules!` macro definition.
-
 ## mutable-transmutes
 
 This lint catches transmuting from `&T` to `&mut T` because it is undefined

src/librustc/lint/builtin.rs

@@ -182,12 +182,6 @@ declare_lint! {
     "detects use of struct constructors that would be invisible with new visibility rules"
 }
 
-declare_lint! {
-    pub MISSING_FRAGMENT_SPECIFIER,
-    Deny,
-    "detects missing fragment specifiers in unused `macro_rules!` patterns"
-}
-
 declare_lint! {
     pub PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
     Deny,
@@ -428,7 +422,6 @@ declare_lint_pass! {
         PATTERNS_IN_FNS_WITHOUT_BODY,
         LEGACY_DIRECTORY_OWNERSHIP,
         LEGACY_CONSTRUCTOR_VISIBILITY,
-        MISSING_FRAGMENT_SPECIFIER,
         PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
         LATE_BOUND_LIFETIME_ARGUMENTS,
         ORDER_DEPENDENT_TRAIT_OBJECTS,

src/librustc_interface/passes.rs

@@ -432,19 +432,6 @@ fn configure_and_expand_inner<'a>(
             ecx.check_unused_macros();
         });
 
-        let mut missing_fragment_specifiers: Vec<_> = ecx.parse_sess
-            .missing_fragment_specifiers
-            .borrow()
-            .iter()
-            .cloned()
-            .collect();
-        missing_fragment_specifiers.sort();
-
-        for span in missing_fragment_specifiers {
-            let lint = lint::builtin::MISSING_FRAGMENT_SPECIFIER;
-            let msg = "missing fragment specifier";
-            sess.buffer_lint(lint, ast::CRATE_NODE_ID, span, msg);
-        }
         if cfg!(windows) {
             env::set_var("PATH", &old_path);
         }

src/librustc_lint/lib.rs

@@ -341,11 +341,6 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
             reference: "issue #39207 <https://github.com/rust-lang/rust/issues/39207>",
             edition: None,
         },
-        FutureIncompatibleInfo {
-            id: LintId::of(MISSING_FRAGMENT_SPECIFIER),
-            reference: "issue #40107 <https://github.com/rust-lang/rust/issues/40107>",
-            edition: None,
-        },
         FutureIncompatibleInfo {
             id: LintId::of(ILLEGAL_FLOATING_POINT_LITERAL_PATTERN),
             reference: "issue #41620 <https://github.com/rust-lang/rust/issues/41620>",
@@ -488,6 +483,8 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
         "converted into hard error, see https://github.com/rust-lang/rust/issues/57742");
     store.register_removed("incoherent_fundamental_impls",
         "converted into hard error, see https://github.com/rust-lang/rust/issues/46205");
+    store.register_removed("missing_fragment_specifier",
+        "converted into hard error, see https://github.com/rust-lang/rust/issues/40107");
 }
 
 pub fn register_internals(store: &mut lint::LintStore, sess: Option<&Session>) {

src/libsyntax/ext/tt/macro_parser.rs

@@ -382,9 +382,7 @@ fn nameize<I: Iterator<Item = NamedMatch>>(
                 n_rec(sess, next_m, res.by_ref(), ret_val)?;
             },
             TokenTree::MetaVarDecl(span, _, id) if id.name == kw::Invalid => {
-                if sess.missing_fragment_specifiers.borrow_mut().remove(&span) {
-                    return Err((span, "missing fragment specifier".to_string()));
-                }
+                return Err((span, "missing fragment specifier".to_string()));
             }
             TokenTree::MetaVarDecl(sp, bind_name, _) => {
                 match ret_val.entry(bind_name) {
@@ -444,7 +442,6 @@ fn token_name_eq(t1: &Token, t2: &Token) -> bool {
 ///
 /// # Parameters
 ///
-/// - `sess`: the parsing session into which errors are emitted.
 /// - `cur_items`: the set of current items to be processed. This should be empty by the end of a
 ///   successful execution of this function.
 /// - `next_items`: the set of newly generated items. These are used to replenish `cur_items` in
@@ -459,7 +456,6 @@ fn token_name_eq(t1: &Token, t2: &Token) -> bool {
 ///
 /// A `ParseResult`. Note that matches are kept track of through the items generated.
 fn inner_parse_loop<'root, 'tt>(
-    sess: &ParseSess,
     cur_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
     next_items: &mut Vec<MatcherPosHandle<'root, 'tt>>,
     eof_items: &mut SmallVec<[MatcherPosHandle<'root, 'tt>; 1]>,
@@ -585,9 +581,7 @@ fn inner_parse_loop<'root, 'tt>(
 
                 // We need to match a metavar (but the identifier is invalid)... this is an error
                 TokenTree::MetaVarDecl(span, _, id) if id.name == kw::Invalid => {
-                    if sess.missing_fragment_specifiers.borrow_mut().remove(&span) {
-                        return Error(span, "missing fragment specifier".to_string());
-                    }
+                    return Error(span, "missing fragment specifier".to_string());
                 }
 
                 // We need to match a metavar with a valid ident... call out to the black-box
@@ -689,7 +683,6 @@ pub fn parse(
         // parsing from the black-box parser done. The result is that `next_items` will contain a
         // bunch of possible next matcher positions in `next_items`.
         match inner_parse_loop(
-            sess,
             &mut cur_items,
             &mut next_items,
             &mut eof_items,

src/libsyntax/ext/tt/quoted.rs

@@ -241,7 +241,9 @@ pub fn parse(
                     }
                     tree => tree.as_ref().map(tokenstream::TokenTree::span).unwrap_or(start_sp),
                 };
-                sess.missing_fragment_specifiers.borrow_mut().insert(span);
+
+                sess.span_diagnostic.span_err(span, "missing fragment specifier");
+
                 result.push(TokenTree::MetaVarDecl(span, ident, ast::Ident::invalid()));
             }
 

src/libsyntax/parse/lexer/tests.rs

@@ -10,7 +10,7 @@ use crate::with_default_globals;
 use std::io;
 use std::path::PathBuf;
 use syntax_pos::{BytePos, Span, NO_EXPANSION, edition::Edition};
-use rustc_data_structures::fx::{FxHashSet, FxHashMap};
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::{Lock, Once};
 
 fn mk_sess(sm: Lrc<SourceMap>) -> ParseSess {
@@ -25,7 +25,6 @@ fn mk_sess(sm: Lrc<SourceMap>) -> ParseSess {
         config: CrateConfig::default(),
         included_mod_stack: Lock::new(Vec::new()),
         source_map: sm,
-        missing_fragment_specifiers: Lock::new(FxHashSet::default()),
         raw_identifier_spans: Lock::new(Vec::new()),
         registered_diagnostics: Lock::new(ErrorMap::new()),
         buffered_lints: Lock::new(vec![]),

src/libsyntax/parse/mod.rs

@@ -44,7 +44,6 @@ pub struct ParseSess {
     pub unstable_features: UnstableFeatures,
     pub config: CrateConfig,
     pub edition: Edition,
-    pub missing_fragment_specifiers: Lock<FxHashSet<Span>>,
     /// Places where raw identifiers were used. This is used for feature-gating raw identifiers.
     pub raw_identifier_spans: Lock<Vec<Span>>,
     /// The registered diagnostics codes.
@@ -80,7 +79,6 @@ impl ParseSess {
             span_diagnostic: handler,
             unstable_features: UnstableFeatures::from_environment(),
             config: FxHashSet::default(),
-            missing_fragment_specifiers: Lock::new(FxHashSet::default()),
             raw_identifier_spans: Lock::new(Vec::new()),
             registered_diagnostics: Lock::new(ErrorMap::new()),
             included_mod_stack: Lock::new(vec![]),

src/test/ui/issues/issue-39404.rs

@@ -1,7 +1,4 @@
-#![allow(unused)]
-
 macro_rules! m { ($i) => {} }
 //~^ ERROR missing fragment specifier
-//~| WARN previously accepted
 
 fn main() {}

src/test/ui/issues/issue-39404.stderr

@@ -1,12 +1,8 @@
 error: missing fragment specifier
-  --> $DIR/issue-39404.rs:3:19
+  --> $DIR/issue-39404.rs:1:19
    |
 LL | macro_rules! m { ($i) => {} }
    |                   ^^
-   |
-   = note: `#[deny(missing_fragment_specifier)]` on by default
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #40107 <https://github.com/rust-lang/rust/issues/40107>
 
 error: aborting due to previous error