diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/stmt.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/stmt.rs | 124 |
1 files changed, 84 insertions, 40 deletions
diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs index 131ff1ae6b3..e974556f43a 100644 --- a/compiler/rustc_parse/src/parser/stmt.rs +++ b/compiler/rustc_parse/src/parser/stmt.rs @@ -7,8 +7,10 @@ use super::{BlockMode, Parser, Restrictions, SemiColonMode}; use crate::maybe_whole; use rustc_ast as ast; +use rustc_ast::attr::HasAttrs; use rustc_ast::ptr::P; use rustc_ast::token::{self, TokenKind}; +use rustc_ast::tokenstream::LazyTokenStream; use rustc_ast::util::classify; use rustc_ast::{AttrStyle, AttrVec, Attribute, MacCall, MacCallStmt, MacStmtStyle}; use rustc_ast::{Block, BlockCheckMode, Expr, ExprKind, Local, Stmt, StmtKind, DUMMY_NODE_ID}; @@ -31,45 +33,75 @@ impl<'a> Parser<'a> { } fn parse_stmt_without_recovery(&mut self) -> PResult<'a, Option<Stmt>> { - maybe_whole!(self, NtStmt, |x| Some(x)); - - let attrs = self.parse_outer_attributes()?; + let mut attrs = self.parse_outer_attributes()?; + let has_attrs = !attrs.is_empty(); let lo = self.token.span; - let stmt = if self.eat_keyword(kw::Let) { - self.parse_local_mk(lo, attrs.into())? - } else if self.is_kw_followed_by_ident(kw::Mut) { - self.recover_stmt_local(lo, attrs.into(), "missing keyword", "let mut")? - } else if self.is_kw_followed_by_ident(kw::Auto) { - self.bump(); // `auto` - let msg = "write `let` instead of `auto` to introduce a new variable"; - self.recover_stmt_local(lo, attrs.into(), msg, "let")? - } else if self.is_kw_followed_by_ident(sym::var) { - self.bump(); // `var` - let msg = "write `let` instead of `var` to introduce a new variable"; - self.recover_stmt_local(lo, attrs.into(), msg, "let")? - } else if self.check_path() && !self.token.is_qpath_start() && !self.is_path_start_item() { - // We have avoided contextual keywords like `union`, items with `crate` visibility, - // or `auto trait` items. We aim to parse an arbitrary path `a::b` but not something - // that starts like a path (1 token), but it fact not a path. - // Also, we avoid stealing syntax from `parse_item_`. - self.parse_stmt_path_start(lo, attrs)? - } else if let Some(item) = self.parse_item_common(attrs.clone(), false, true, |_| true)? { - // FIXME: Bad copy of attrs - self.mk_stmt(lo.to(item.span), StmtKind::Item(P(item))) - } else if self.eat(&token::Semi) { - // Do not attempt to parse an expression if we're done here. - self.error_outer_attrs(&attrs); - self.mk_stmt(lo, StmtKind::Empty) - } else if self.token != token::CloseDelim(token::Brace) { - // Remainder are line-expr stmts. - let e = self.parse_expr_res(Restrictions::STMT_EXPR, Some(attrs.into()))?; - self.mk_stmt(lo.to(e.span), StmtKind::Expr(e)) + maybe_whole!(self, NtStmt, |stmt| { + let mut stmt = stmt; + stmt.visit_attrs(|stmt_attrs| { + mem::swap(stmt_attrs, &mut attrs); + stmt_attrs.extend(attrs); + }); + Some(stmt) + }); + + let parse_stmt_inner = |this: &mut Self| { + let stmt = if this.eat_keyword(kw::Let) { + this.parse_local_mk(lo, attrs.into())? + } else if this.is_kw_followed_by_ident(kw::Mut) { + this.recover_stmt_local(lo, attrs.into(), "missing keyword", "let mut")? + } else if this.is_kw_followed_by_ident(kw::Auto) { + this.bump(); // `auto` + let msg = "write `let` instead of `auto` to introduce a new variable"; + this.recover_stmt_local(lo, attrs.into(), msg, "let")? + } else if this.is_kw_followed_by_ident(sym::var) { + this.bump(); // `var` + let msg = "write `let` instead of `var` to introduce a new variable"; + this.recover_stmt_local(lo, attrs.into(), msg, "let")? + } else if this.check_path() + && !this.token.is_qpath_start() + && !this.is_path_start_item() + { + // We have avoided contextual keywords like `union`, items with `crate` visibility, + // or `auto trait` items. We aim to parse an arbitrary path `a::b` but not something + // that starts like a path (1 token), but it fact not a path. + // Also, we avoid stealing syntax from `parse_item_`. + this.parse_stmt_path_start(lo, attrs)? + } else if let Some(item) = + this.parse_item_common(attrs.clone(), false, true, |_| true)? + { + // FIXME: Bad copy of attrs + this.mk_stmt(lo.to(item.span), StmtKind::Item(P(item))) + } else if this.eat(&token::Semi) { + // Do not attempt to parse an expression if we're done here. + this.error_outer_attrs(&attrs); + this.mk_stmt(lo, StmtKind::Empty) + } else if this.token != token::CloseDelim(token::Brace) { + // Remainder are line-expr stmts. + let e = this.parse_expr_res(Restrictions::STMT_EXPR, Some(attrs.into()))?; + this.mk_stmt(lo.to(e.span), StmtKind::Expr(e)) + } else { + this.error_outer_attrs(&attrs); + return Ok(None); + }; + Ok(Some(stmt)) + }; + + let stmt = if has_attrs { + let (mut stmt, tokens) = self.collect_tokens(parse_stmt_inner)?; + if let Some(stmt) = &mut stmt { + // If we already have tokens (e.g. due to encounting an `NtStmt`), + // use those instead. + if stmt.tokens().is_none() { + stmt.set_tokens(tokens); + } + } + stmt } else { - self.error_outer_attrs(&attrs); - return Ok(None); + parse_stmt_inner(self)? }; - Ok(Some(stmt)) + Ok(stmt) } fn parse_stmt_path_start(&mut self, lo: Span, attrs: Vec<Attribute>) -> PResult<'a, Stmt> { @@ -107,7 +139,7 @@ impl<'a> Parser<'a> { let kind = if delim == token::Brace || self.token == token::Semi || self.token == token::Eof { - StmtKind::MacCall(P(MacCallStmt { mac, style, attrs })) + StmtKind::MacCall(P(MacCallStmt { mac, style, attrs, tokens: None })) } else { // Since none of the above applied, this is an expression statement macro. let e = self.mk_expr(lo.to(hi), ExprKind::MacCall(mac), AttrVec::new()); @@ -219,7 +251,7 @@ impl<'a> Parser<'a> { } }; let hi = if self.token == token::Semi { self.token.span } else { self.prev_token.span }; - Ok(P(ast::Local { ty, pat, init, id: DUMMY_NODE_ID, span: lo.to(hi), attrs })) + Ok(P(ast::Local { ty, pat, init, id: DUMMY_NODE_ID, span: lo.to(hi), attrs, tokens: None })) } /// Parses the RHS of a local variable declaration (e.g., '= 14;'). @@ -376,6 +408,12 @@ impl<'a> Parser<'a> { None => return Ok(None), }; + let add_semi_token = |tokens: Option<&mut LazyTokenStream>| { + if let Some(tokens) = tokens { + *tokens = tokens.add_trailing_semi(); + } + }; + let mut eat_semi = true; match stmt.kind { // Expression without semicolon. @@ -417,6 +455,7 @@ impl<'a> Parser<'a> { *expr = self.mk_expr_err(sp); } } + StmtKind::Expr(_) | StmtKind::MacCall(_) => {} StmtKind::Local(ref mut local) => { if let Err(e) = self.expect_semi() { // We might be at the `,` in `let x = foo<bar, baz>;`. Try to recover. @@ -430,13 +469,18 @@ impl<'a> Parser<'a> { } } eat_semi = false; + // We just checked that there's a semicolon in the tokenstream, + // so capture it + add_semi_token(local.tokens.as_mut()); } - StmtKind::Empty => eat_semi = false, - _ => {} + StmtKind::Empty | StmtKind::Item(_) | StmtKind::Semi(_) => eat_semi = false, } if eat_semi && self.eat(&token::Semi) { stmt = stmt.add_trailing_semicolon(); + // We just checked that we have a semicolon in the tokenstream, + // so capture it + add_semi_token(stmt.tokens_mut()); } stmt.span = stmt.span.to(self.prev_token.span); Ok(Some(stmt)) @@ -447,7 +491,7 @@ impl<'a> Parser<'a> { } pub(super) fn mk_stmt(&self, span: Span, kind: StmtKind) -> Stmt { - Stmt { id: DUMMY_NODE_ID, kind, span, tokens: None } + Stmt { id: DUMMY_NODE_ID, kind, span } } pub(super) fn mk_stmt_err(&self, span: Span) -> Stmt { |