From f52d1d3eb5d114de7aaf7dfde6b752f48e8f2bc1 Mon Sep 17 00:00:00 2001 From: raskad <32105367+raskad@users.noreply.github.com> Date: Sun, 15 Jan 2023 08:01:24 +0000 Subject: [PATCH] Recognize Directive Prologues correctly (#2521) This Pull Request changes the following: - Recognize the `"use strict"` directive prologue correctly. - Refactor parsers to remove a setter function. --- boa_ast/src/statement_list.rs | 18 ++-- boa_parser/src/parser/function/mod.rs | 36 +------- boa_parser/src/parser/mod.rs | 90 +++++++++---------- boa_parser/src/parser/statement/block/mod.rs | 2 + .../declaration/hoistable/class_decl/mod.rs | 12 ++- boa_parser/src/parser/statement/mod.rs | 34 ++++++- boa_parser/src/parser/statement/switch/mod.rs | 4 + 7 files changed, 104 insertions(+), 92 deletions(-) diff --git a/boa_ast/src/statement_list.rs b/boa_ast/src/statement_list.rs index 1e6cacf6da..2202cc8df0 100644 --- a/boa_ast/src/statement_list.rs +++ b/boa_ast/src/statement_list.rs @@ -121,6 +121,18 @@ pub struct StatementList { } impl StatementList { + /// Creates a new `StatementList` AST node. + #[must_use] + pub fn new(statements: S, strict: bool) -> Self + where + S: Into>, + { + Self { + statements: statements.into(), + strict, + } + } + /// Gets the list of statements. #[inline] #[must_use] @@ -134,12 +146,6 @@ impl StatementList { pub const fn strict(&self) -> bool { self.strict } - - /// Set the strict mode. - #[inline] - pub fn set_strict(&mut self, strict: bool) { - self.strict = strict; - } } impl From> for StatementList { diff --git a/boa_parser/src/parser/function/mod.rs b/boa_parser/src/parser/function/mod.rs index fd58d9bf47..0607aeba5d 100644 --- a/boa_parser/src/parser/function/mod.rs +++ b/boa_parser/src/parser/function/mod.rs @@ -26,7 +26,6 @@ use boa_ast::{ Punctuator, }; use boa_interner::{Interner, Sym}; -use boa_macros::utf16; use boa_profiler::Profiler; use std::io::Read; @@ -449,41 +448,14 @@ where fn parse(self, cursor: &mut Cursor, interner: &mut Interner) -> ParseResult { let _timer = Profiler::global().start_event("FunctionStatementList", "Parsing"); - let global_strict_mode = cursor.strict_mode(); - let mut strict = false; - - if let Some(tk) = cursor.peek(0, interner)? { - match tk.kind() { - TokenKind::Punctuator(Punctuator::CloseBlock) => { - return Ok(Vec::new().into()); - } - TokenKind::StringLiteral(string) - if interner.resolve_expect(*string).join( - |s| s == "use strict", - |g| g == utf16!("use strict"), - true, - ) => - { - cursor.set_strict_mode(true); - strict = true; - } - _ => {} - } - } - - let statement_list = StatementList::new( + StatementList::new( self.allow_yield, self.allow_await, true, &FUNCTION_BREAK_TOKENS, + true, + false, ) - .parse(cursor, interner); - - // Reset strict mode back to the global scope. - cursor.set_strict_mode(global_strict_mode); - - let mut statement_list = statement_list?; - statement_list.set_strict(strict); - Ok(statement_list) + .parse(cursor, interner) } } diff --git a/boa_parser/src/parser/mod.rs b/boa_parser/src/parser/mod.rs index e8a55f6655..18363fdc0b 100644 --- a/boa_parser/src/parser/mod.rs +++ b/boa_parser/src/parser/mod.rs @@ -11,7 +11,6 @@ mod tests; use crate::{ error::ParseResult, - lexer::TokenKind, parser::{ cursor::Cursor, function::{FormalParameters, FunctionStatementList}, @@ -27,7 +26,6 @@ use boa_ast::{ Position, StatementList, }; use boa_interner::Interner; -use boa_macros::utf16; use rustc_hash::FxHashSet; use std::io::Read; @@ -239,52 +237,31 @@ where type Output = StatementList; fn parse(self, cursor: &mut Cursor, interner: &mut Interner) -> ParseResult { - let mut strict = cursor.strict_mode(); - match cursor.peek(0, interner)? { - Some(tok) => { - match tok.kind() { - // Set the strict mode - TokenKind::StringLiteral(string) - if interner.resolve_expect(*string).join( - |s| s == "use strict", - |g| g == utf16!("use strict"), - true, - ) => - { - cursor.set_strict_mode(true); - strict = true; - } - _ => {} - } - let mut statement_list = - ScriptBody::new(self.direct_eval).parse(cursor, interner)?; - statement_list.set_strict(strict); - - // It is a Syntax Error if the LexicallyDeclaredNames of ScriptBody contains any duplicate entries. - // It is a Syntax Error if any element of the LexicallyDeclaredNames of ScriptBody also occurs in the VarDeclaredNames of ScriptBody. - let mut lexical_names = FxHashSet::default(); - for name in top_level_lexically_declared_names(&statement_list) { - if !lexical_names.insert(name) { - return Err(Error::general( - "lexical name declared multiple times", - Position::new(1, 1), - )); - } - } - - for name in top_level_var_declared_names(&statement_list) { - if lexical_names.contains(&name) { - return Err(Error::general( - "lexical name declared multiple times", - Position::new(1, 1), - )); - } - } - - Ok(statement_list) + let statement_list = ScriptBody::new(true, cursor.strict_mode(), self.direct_eval) + .parse(cursor, interner)?; + + // It is a Syntax Error if the LexicallyDeclaredNames of ScriptBody contains any duplicate entries. + // It is a Syntax Error if any element of the LexicallyDeclaredNames of ScriptBody also occurs in the VarDeclaredNames of ScriptBody. + let mut lexical_names = FxHashSet::default(); + for name in top_level_lexically_declared_names(&statement_list) { + if !lexical_names.insert(name) { + return Err(Error::general( + "lexical name declared multiple times", + Position::new(1, 1), + )); } - None => Ok(StatementList::from(Vec::new())), } + + for name in top_level_var_declared_names(&statement_list) { + if lexical_names.contains(&name) { + return Err(Error::general( + "lexical name declared multiple times", + Position::new(1, 1), + )); + } + } + + Ok(statement_list) } } @@ -296,14 +273,20 @@ where /// [spec]: https://tc39.es/ecma262/#prod-ScriptBody #[derive(Debug, Clone, Copy)] pub struct ScriptBody { + directive_prologues: bool, + strict: bool, direct_eval: bool, } impl ScriptBody { /// Create a new `ScriptBody` parser. #[inline] - const fn new(direct_eval: bool) -> Self { - Self { direct_eval } + const fn new(directive_prologues: bool, strict: bool, direct_eval: bool) -> Self { + Self { + directive_prologues, + strict, + direct_eval, + } } } @@ -314,8 +297,15 @@ where type Output = StatementList; fn parse(self, cursor: &mut Cursor, interner: &mut Interner) -> ParseResult { - let body = self::statement::StatementList::new(false, false, false, &[]) - .parse(cursor, interner)?; + let body = self::statement::StatementList::new( + false, + false, + false, + &[], + self.directive_prologues, + self.strict, + ) + .parse(cursor, interner)?; if !self.direct_eval { // It is a Syntax Error if StatementList Contains super unless the source text containing super is eval diff --git a/boa_parser/src/parser/statement/block/mod.rs b/boa_parser/src/parser/statement/block/mod.rs index f0cf432ae4..688d296499 100644 --- a/boa_parser/src/parser/statement/block/mod.rs +++ b/boa_parser/src/parser/statement/block/mod.rs @@ -90,6 +90,8 @@ where self.allow_await, self.allow_return, &BLOCK_BREAK_TOKENS, + false, + false, ) .parse(cursor, interner) .map(statement::Block::from)?; diff --git a/boa_parser/src/parser/statement/declaration/hoistable/class_decl/mod.rs b/boa_parser/src/parser/statement/declaration/hoistable/class_decl/mod.rs index a988670f66..aa4e97cc29 100644 --- a/boa_parser/src/parser/statement/declaration/hoistable/class_decl/mod.rs +++ b/boa_parser/src/parser/statement/declaration/hoistable/class_decl/mod.rs @@ -666,9 +666,15 @@ where let strict = cursor.strict_mode(); cursor.set_strict_mode(true); let position = cursor.peek(0, interner).or_abrupt()?.span().start(); - let statement_list = - StatementList::new(false, true, false, &FUNCTION_BREAK_TOKENS) - .parse(cursor, interner)?; + let statement_list = StatementList::new( + false, + true, + false, + &FUNCTION_BREAK_TOKENS, + false, + false, + ) + .parse(cursor, interner)?; let mut lexical_names = FxHashSet::default(); for name in &lexically_declared_names(&statement_list) { diff --git a/boa_parser/src/parser/statement/mod.rs b/boa_parser/src/parser/statement/mod.rs index 76a3ee4718..1b9ff048c5 100644 --- a/boa_parser/src/parser/statement/mod.rs +++ b/boa_parser/src/parser/statement/mod.rs @@ -50,6 +50,7 @@ use boa_ast::{ Keyword, Punctuator, }; use boa_interner::Interner; +use boa_macros::utf16; use boa_profiler::Profiler; use std::io::Read; @@ -228,6 +229,8 @@ pub(super) struct StatementList { allow_await: AllowAwait, allow_return: AllowReturn, break_nodes: &'static [TokenKind], + directive_prologues: bool, + strict: bool, } impl StatementList { @@ -237,6 +240,8 @@ impl StatementList { allow_await: A, allow_return: R, break_nodes: &'static [TokenKind], + directive_prologues: bool, + strict: bool, ) -> Self where Y: Into, @@ -248,6 +253,8 @@ impl StatementList { allow_await: allow_await.into(), allow_return: allow_return.into(), break_nodes, + directive_prologues, + strict, } } } @@ -272,6 +279,10 @@ where let _timer = Profiler::global().start_event("StatementList", "Parsing"); let mut items = Vec::new(); + let global_strict = cursor.strict_mode(); + let mut directive_prologues = self.directive_prologues; + let mut strict = self.strict; + loop { match cursor.peek(0, interner)? { Some(token) if self.break_nodes.contains(token.kind()) => break, @@ -282,6 +293,25 @@ where let item = StatementListItem::new(self.allow_yield, self.allow_await, self.allow_return) .parse(cursor, interner)?; + + if directive_prologues { + if let ast::StatementListItem::Statement(ast::Statement::Expression( + ast::Expression::Literal(ast::expression::literal::Literal::String(string)), + )) = &item + { + if interner.resolve_expect(*string).join( + |s| s == "use strict", + |g| g == utf16!("use strict"), + true, + ) { + cursor.set_strict_mode(true); + strict = true; + } + } else { + directive_prologues = false; + } + } + items.push(item); // move the cursor forward for any consecutive semicolon. @@ -290,7 +320,9 @@ where items.sort_by(ast::StatementListItem::hoistable_order); - Ok(items.into()) + cursor.set_strict_mode(global_strict); + + Ok(ast::StatementList::new(items, strict)) } } diff --git a/boa_parser/src/parser/statement/switch/mod.rs b/boa_parser/src/parser/statement/switch/mod.rs index 65a8d29627..d08ea4b0fb 100644 --- a/boa_parser/src/parser/statement/switch/mod.rs +++ b/boa_parser/src/parser/statement/switch/mod.rs @@ -173,6 +173,8 @@ where self.allow_await, self.allow_return, &CASE_BREAK_TOKENS, + false, + false, ) .parse(cursor, interner)?; @@ -195,6 +197,8 @@ where self.allow_await, self.allow_return, &CASE_BREAK_TOKENS, + false, + false, ) .parse(cursor, interner)?;