diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/stmt.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/stmt.rs | 60 |
1 files changed, 42 insertions, 18 deletions
diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs index 3a9dc5ce798..0896bd88b4c 100644 --- a/compiler/rustc_parse/src/parser/stmt.rs +++ b/compiler/rustc_parse/src/parser/stmt.rs @@ -5,7 +5,7 @@ use std::ops::Bound; use ast::Label; use rustc_ast as ast; use rustc_ast::ptr::P; -use rustc_ast::token::{self, Delimiter, TokenKind}; +use rustc_ast::token::{self, Delimiter, InvisibleOrigin, MetaVarKind, TokenKind}; use rustc_ast::util::classify::{self, TrailingBrace}; use rustc_ast::{ AttrStyle, AttrVec, Block, BlockCheckMode, DUMMY_NODE_ID, Expr, ExprKind, HasAttrs, Local, @@ -33,8 +33,8 @@ impl<'a> Parser<'a> { /// If `force_collect` is [`ForceCollect::Yes`], forces collection of tokens regardless of /// whether or not we have attributes. // Public for rustfmt usage. - pub(super) fn parse_stmt(&mut self, force_collect: ForceCollect) -> PResult<'a, Option<Stmt>> { - Ok(self.parse_stmt_without_recovery(false, force_collect).unwrap_or_else(|e| { + pub fn parse_stmt(&mut self, force_collect: ForceCollect) -> PResult<'a, Option<Stmt>> { + Ok(self.parse_stmt_without_recovery(false, force_collect, false).unwrap_or_else(|e| { e.emit(); self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore); None @@ -42,23 +42,27 @@ impl<'a> Parser<'a> { } /// If `force_collect` is [`ForceCollect::Yes`], forces collection of tokens regardless of - /// whether or not we have attributes. - // Public for `cfg_eval` macro expansion. + /// whether or not we have attributes. If `force_full_expr` is true, parses the stmt without + /// using `Restriction::STMT_EXPR`. Public for `cfg_eval` macro expansion. pub fn parse_stmt_without_recovery( &mut self, capture_semi: bool, force_collect: ForceCollect, + force_full_expr: bool, ) -> PResult<'a, Option<Stmt>> { let pre_attr_pos = self.collect_pos(); let attrs = self.parse_outer_attributes()?; let lo = self.token.span; - maybe_whole!(self, NtStmt, |stmt| { + if let Some(stmt) = self.eat_metavar_seq(MetaVarKind::Stmt, |this| { + this.parse_stmt_without_recovery(false, ForceCollect::Yes, false) + }) { + let mut stmt = stmt.expect("an actual statement"); stmt.visit_attrs(|stmt_attrs| { attrs.prepend_to_nt_inner(stmt_attrs); }); - Some(stmt.into_inner()) - }); + return Ok(Some(stmt)); + } if self.token.is_keyword(kw::Mut) && self.is_keyword_ahead(1, &[kw::Let]) { self.bump(); @@ -147,12 +151,14 @@ impl<'a> Parser<'a> { } else if self.token != token::CloseDelim(Delimiter::Brace) { // Remainder are line-expr stmts. This is similar to the `parse_stmt_path_start` case // above. + let restrictions = + if force_full_expr { Restrictions::empty() } else { Restrictions::STMT_EXPR }; let e = self.collect_tokens( Some(pre_attr_pos), AttrWrapper::empty(), force_collect, |this, _empty_attrs| { - let (expr, _) = this.parse_expr_res(Restrictions::STMT_EXPR, attrs)?; + let (expr, _) = this.parse_expr_res(restrictions, attrs)?; Ok((expr, Trailing::No, UsePreAttrPos::Yes)) }, )?; @@ -229,11 +235,15 @@ impl<'a> Parser<'a> { let mac = P(MacCall { path, args }); let kind = if (style == MacStmtStyle::Braces - && self.token != token::Dot - && self.token != token::Question) - || self.token == token::Semi - || self.token == token::Eof - { + && !matches!(self.token.kind, token::Dot | token::Question)) + || matches!( + self.token.kind, + token::Semi + | token::Eof + | token::CloseDelim(Delimiter::Invisible(InvisibleOrigin::MetaVar( + MetaVarKind::Stmt + ))) + ) { StmtKind::MacCall(P(MacCallStmt { mac, style, attrs, tokens: None })) } else { // Since none of the above applied, this is an expression statement macro. @@ -501,7 +511,7 @@ impl<'a> Parser<'a> { // bar; // // which is valid in other languages, but not Rust. - match self.parse_stmt_without_recovery(false, ForceCollect::No) { + match self.parse_stmt_without_recovery(false, ForceCollect::No, false) { // If the next token is an open brace, e.g., we have: // // if expr other_expr { @@ -810,10 +820,24 @@ impl<'a> Parser<'a> { &mut self, recover: AttemptLocalParseRecovery, ) -> PResult<'a, Option<Stmt>> { - // Skip looking for a trailing semicolon when we have an interpolated statement. - maybe_whole!(self, NtStmt, |stmt| Some(stmt.into_inner())); + // Skip looking for a trailing semicolon when we have a metavar seq. + if let Some(stmt) = self.eat_metavar_seq(MetaVarKind::Stmt, |this| { + // Why pass `true` for `force_full_expr`? Statement expressions are less expressive + // than "full" expressions, due to the `STMT_EXPR` restriction, and sometimes need + // parentheses. E.g. the "full" expression `match paren_around_match {} | true` when + // used in statement context must be written `(match paren_around_match {} | true)`. + // However, if the expression we are parsing in this statement context was pasted by a + // declarative macro, it may have come from a "full" expression context, and lack + // these parentheses. So we lift the `STMT_EXPR` restriction to ensure the statement + // will reparse successfully. + this.parse_stmt_without_recovery(false, ForceCollect::No, true) + }) { + let stmt = stmt.expect("an actual statement"); + return Ok(Some(stmt)); + } - let Some(mut stmt) = self.parse_stmt_without_recovery(true, ForceCollect::No)? else { + let Some(mut stmt) = self.parse_stmt_without_recovery(true, ForceCollect::No, false)? + else { return Ok(None); }; |