diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/rustc_expand/Cargo.toml | 1 | ||||
| -rw-r--r-- | compiler/rustc_expand/src/mbe/macro_rules.rs | 14 | ||||
| -rw-r--r-- | compiler/rustc_lint_defs/src/builtin.rs | 48 | ||||
| -rw-r--r-- | compiler/rustc_resolve/src/macros.rs | 2 |
4 files changed, 64 insertions, 1 deletions
diff --git a/compiler/rustc_expand/Cargo.toml b/compiler/rustc_expand/Cargo.toml index 25c2851f6de..7413b0d9431 100644 --- a/compiler/rustc_expand/Cargo.toml +++ b/compiler/rustc_expand/Cargo.toml @@ -18,6 +18,7 @@ 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" } diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs index e8c711cae64..73fbde70bda 100644 --- a/compiler/rustc_expand/src/mbe/macro_rules.rs +++ b/compiler/rustc_expand/src/mbe/macro_rules.rs @@ -11,12 +11,14 @@ 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; @@ -37,6 +39,7 @@ 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, } @@ -110,7 +113,8 @@ 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, arm_span } = *self; + let ParserAnyMacro { site_span, macro_ident, ref mut parser, lint_node_id, arm_span } = + *self; let snapshot = &mut parser.clone(); let fragment = match parse_ast_fragment(parser, kind) { Ok(f) => f, @@ -124,6 +128,12 @@ 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(); } @@ -276,6 +286,7 @@ 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. @@ -287,6 +298,7 @@ fn generic_extension<'cx>( // macro leaves unparsed tokens. site_span: sp, macro_ident: name, + lint_node_id, arm_span, }); } diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs index 658372ac336..a8bf1ce51bb 100644 --- a/compiler/rustc_lint_defs/src/builtin.rs +++ b/compiler/rustc_lint_defs/src/builtin.rs @@ -1,3 +1,4 @@ +// ignore-tidy-filelength //! Some lints that are built in to the compiler. //! //! These are the built-in lints that are emitted direct in the main @@ -2833,6 +2834,52 @@ 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. @@ -2920,6 +2967,7 @@ declare_lint_pass! { USELESS_DEPRECATED, UNSUPPORTED_NAKED_FUNCTIONS, MISSING_ABI, + SEMICOLON_IN_EXPRESSIONS_FROM_MACROS, ] } diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs index 5d6120cd310..d0adee2429d 100644 --- a/compiler/rustc_resolve/src/macros.rs +++ b/compiler/rustc_resolve/src/macros.rs @@ -344,6 +344,8 @@ 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]) |