Revert "Add SEMICOLON_IN_EXPRESSIONS_FROM_MACROS lint"

This reverts commit f902551.

Author: Jethro Beekman

Cargo.lock

@@ -3747,7 +3747,6 @@ dependencies = [
  "rustc_errors",
  "rustc_feature",
  "rustc_lexer",
- "rustc_lint_defs",
  "rustc_macros",
  "rustc_parse",
  "rustc_serialize",

compiler/rustc_expand/Cargo.toml

@@ -18,7 +18,6 @@ rustc_attr = { path = "../rustc_attr" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_feature = { path = "../rustc_feature" }
-rustc_lint_defs = { path = "../rustc_lint_defs" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_lexer = { path = "../rustc_lexer" }
 rustc_parse = { path = "../rustc_parse" }

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -11,14 +11,12 @@ use crate::mbe::transcribe::transcribe;
 use rustc_ast as ast;
 use rustc_ast::token::{self, NonterminalKind, NtTT, Token, TokenKind::*};
 use rustc_ast::tokenstream::{DelimSpan, TokenStream};
-use rustc_ast::NodeId;
 use rustc_ast_pretty::pprust;
 use rustc_attr::{self as attr, TransparencyError};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_feature::Features;
-use rustc_lint_defs::builtin::SEMICOLON_IN_EXPRESSIONS_FROM_MACROS;
 use rustc_parse::parser::Parser;
 use rustc_session::parse::ParseSess;
 use rustc_session::Session;
@@ -39,7 +37,6 @@ crate struct ParserAnyMacro<'a> {
     site_span: Span,
     /// The ident of the macro we're parsing
     macro_ident: Ident,
-    lint_node_id: NodeId,
     arm_span: Span,
 }
 
@@ -113,8 +110,7 @@ fn emit_frag_parse_err(
 
 impl<'a> ParserAnyMacro<'a> {
     crate fn make(mut self: Box<ParserAnyMacro<'a>>, kind: AstFragmentKind) -> AstFragment {
-        let ParserAnyMacro { site_span, macro_ident, ref mut parser, lint_node_id, arm_span } =
-            *self;
+        let ParserAnyMacro { site_span, macro_ident, ref mut parser, arm_span } = *self;
         let snapshot = &mut parser.clone();
         let fragment = match parse_ast_fragment(parser, kind) {
             Ok(f) => f,
@@ -128,12 +124,6 @@ impl<'a> ParserAnyMacro<'a> {
         // `macro_rules! m { () => { panic!(); } }` isn't parsed by `.parse_expr()`,
         // but `m!()` is allowed in expression positions (cf. issue #34706).
         if kind == AstFragmentKind::Expr && parser.token == token::Semi {
-            parser.sess.buffer_lint(
-                SEMICOLON_IN_EXPRESSIONS_FROM_MACROS,
-                parser.token.span,
-                lint_node_id,
-                "trailing semicolon in macro used in expression position",
-            );
             parser.bump();
         }
 
@@ -286,7 +276,6 @@ fn generic_extension<'cx>(
 
                 let mut p = Parser::new(sess, tts, false, None);
                 p.last_type_ascription = cx.current_expansion.prior_type_ascription;
-                let lint_node_id = cx.resolver.lint_node_id(cx.current_expansion.id);
 
                 // Let the context choose how to interpret the result.
                 // Weird, but useful for X-macros.
@@ -298,7 +287,6 @@ fn generic_extension<'cx>(
                     // macro leaves unparsed tokens.
                     site_span: sp,
                     macro_ident: name,
-                    lint_node_id,
                     arm_span,
                 });
             }

compiler/rustc_lint_defs/src/builtin.rs

@@ -2834,52 +2834,6 @@ declare_lint! {
     "detects `#[unstable]` on stable trait implementations for stable types"
 }
 
-declare_lint! {
-    /// The `semicolon_in_expressions_from_macros` lint detects trailing semicolons
-    /// in macro bodies when the macro is invoked in expression position.
-    /// This was previous accepted, but is being phased out.
-    ///
-    /// ### Example
-    ///
-    /// ```rust,compile_fail
-    /// #![deny(semicolon_in_expressions_from_macros)]
-    /// macro_rules! foo {
-    ///     () => { true; }
-    /// }
-    ///
-    /// fn main() {
-    ///     let val = match true {
-    ///         true => false,
-    ///         _ => foo!()
-    ///     };
-    /// }
-    /// ```
-    ///
-    /// {{produces}}
-    ///
-    /// ### Explanation
-    ///
-    /// Previous, Rust ignored trailing semicolon in a macro
-    /// body when a macro was invoked in expression position.
-    /// However, this makes the treatment of semicolons in the language
-    /// inconsistent, and could lead to unexpected runtime behavior
-    /// in some circumstances (e.g. if the macro author expects
-    /// a value to be dropped).
-    ///
-    /// This is a [future-incompatible] lint to transition this
-    /// to a hard error in the future. See [issue #79813] for more details.
-    ///
-    /// [issue #79813]: https://github.com/rust-lang/rust/issues/79813
-    /// [future-incompatible]: ../index.md#future-incompatible-lints
-    pub SEMICOLON_IN_EXPRESSIONS_FROM_MACROS,
-    Allow,
-    "trailing semicolon in macro body used as expression",
-    @future_incompatible = FutureIncompatibleInfo {
-        reference: "issue #79813 <https://github.com/rust-lang/rust/issues/79813>",
-        edition: None,
-    };
-}
-
 declare_lint_pass! {
     /// Does nothing as a lint pass, but registers some `Lint`s
     /// that are used by other parts of the compiler.
@@ -2967,7 +2921,6 @@ declare_lint_pass! {
         USELESS_DEPRECATED,
         UNSUPPORTED_NAKED_FUNCTIONS,
         MISSING_ABI,
-        SEMICOLON_IN_EXPRESSIONS_FROM_MACROS,
         DISJOINT_CAPTURE_DROP_REORDER,
     ]
 }

compiler/rustc_resolve/src/macros.rs

@@ -344,8 +344,6 @@ impl<'a> ResolverExpand for Resolver<'a> {
     }
 
     fn lint_node_id(&mut self, expn_id: ExpnId) -> NodeId {
-        // FIXME - make this more precise. This currently returns the NodeId of the
-        // nearest closing item - we should try to return the closest parent of the ExpnId
         self.invocation_parents
             .get(&expn_id)
             .map_or(ast::CRATE_NODE_ID, |id| self.def_id_to_node_id[*id])

src/bootstrap/bootstrap.py

@@ -834,7 +834,6 @@ def build_bootstrap(self):
         target_linker = self.get_toml("linker", build_section)
         if target_linker is not None:
             env["RUSTFLAGS"] += " -C linker=" + target_linker
-        # cfg(bootstrap): Add `-Wsemicolon_in_expressions_from_macros` after the next beta bump
         env["RUSTFLAGS"] += " -Wrust_2018_idioms -Wunused_lifetimes"
         if self.get_toml("deny-warnings", "rust") != "false":
             env["RUSTFLAGS"] += " -Dwarnings"

src/bootstrap/builder.rs

@@ -1258,12 +1258,6 @@ impl<'a> Builder<'a> {
             // some code doesn't go through this `rustc` wrapper.
             lint_flags.push("-Wrust_2018_idioms");
             lint_flags.push("-Wunused_lifetimes");
-            // cfg(bootstrap): unconditionally enable this warning after the next beta bump
-            // This is currently disabled for the stage1 libstd, since build scripts
-            // will end up using the bootstrap compiler (which doesn't yet support this lint)
-            if compiler.stage != 0 && mode != Mode::Std {
-                lint_flags.push("-Wsemicolon_in_expressions_from_macros");
-            }
 
             if self.config.deny_warnings {
                 lint_flags.push("-Dwarnings");