LibJS: Do not execute scripts with parse errors

This adds missing checks in several LibJS consumers.
akimdi · Apr 13, 2020 · 984c290 · 984c290
1 parent 50b6b6e
commit 984c290
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Showing 4 changed files with 36 additions and 7 deletions.
diff --git a/Libraries/LibJS/Parser.h b/Libraries/LibJS/Parser.h
@@ -72,7 +72,7 @@ class Parser {
  NonnullRefPtr<NewExpression> parse_new_expression();
  RefPtr<FunctionExpression> try_parse_arrow_function_expression(bool expect_parens);
 
- bool has_errors() const { return m_parser_state.m_has_errors; }
+ bool has_errors() const { return m_parser_state.m_lexer.has_errors() || m_parser_state.m_has_errors; }
 
 private:
  int operator_precedence(TokenType) const;

diff --git a/Libraries/LibWeb/DOM/Document.cpp b/Libraries/LibWeb/DOM/Document.cpp
@@ -374,7 +374,11 @@ JS::Interpreter& Document::interpreter()
 
 JS::Value Document::run_javascript(const StringView& source)
 {
- auto program = JS::Parser(JS::Lexer(source)).parse_program();
+ auto parser = JS::Parser(JS::Lexer(source));
+ auto program = parser.parse_program();
+ if (parser.has_errors()) {
+ return JS::js_undefined();
+ }
  dbg() << "Document::run_javascript('" << source << "') will run:";
  program->dump(0);
  return document().interpreter().run(*program);

diff --git a/Libraries/LibWeb/DOM/HTMLScriptElement.cpp b/Libraries/LibWeb/DOM/HTMLScriptElement.cpp
@@ -59,7 +59,11 @@ void HTMLScriptElement::children_changed()
  if (source.is_empty())
  return;
 
- auto program = JS::Parser(JS::Lexer(source)).parse_program();
+ auto parser = JS::Parser(JS::Lexer(source));
+ auto program = parser.parse_program();
+ if (parser.has_errors())
+ return;
+
  document().interpreter().run(*program);
 }
 
@@ -90,7 +94,11 @@ void HTMLScriptElement::inserted_into(Node& new_parent)
  return;
  }
 
- auto program = JS::Parser(JS::Lexer(source)).parse_program();
+ auto parser = JS::Parser(JS::Lexer(source));
+ auto program = parser.parse_program();
+ if (parser.has_errors())
+ return;
+
  document().interpreter().run(*program);
 }
 

diff --git a/Userland/js.cpp b/Userland/js.cpp
@@ -328,9 +328,14 @@ JS::Value ReplObject::load_file(JS::Interpreter& interpreter)
  } else {
  source = file_contents;
  }
- auto program = JS::Parser(JS::Lexer(source)).parse_program();
+ auto parser = JS::Parser(JS::Lexer(source));
+ auto program = parser.parse_program();
  if (dump_ast)
  program->dump(0);
+
+ if (parser.has_errors())
+ continue;
+
  interpreter.run(*program);
  if (print_last_result)
  print(interpreter.last_value());
@@ -345,10 +350,16 @@ void repl(JS::Interpreter& interpreter)
  if (piece.is_empty())
  continue;
  repl_statements.append(piece);
- auto program = JS::Parser(JS::Lexer(piece)).parse_program();
+ auto parser = JS::Parser(JS::Lexer(piece));
+ auto program = parser.parse_program();
  if (dump_ast)
  program->dump(0);
 
+ if (parser.has_errors()) {
+ printf("Parse error\n");
+ continue;
+ }
+
  interpreter.run(*program);
  if (interpreter.exception()) {
  printf("Uncaught exception: ");
@@ -634,11 +645,17 @@ int main(int argc, char** argv)
  } else {
  source = file_contents;
  }
- auto program = JS::Parser(JS::Lexer(source)).parse_program();
+ auto parser = JS::Parser(JS::Lexer(source));
+ auto program = parser.parse_program();
 
  if (dump_ast)
  program->dump(0);
 
+ if (parser.has_errors()) {
+ printf("Parse Error\n");
+ return 1;
+ }
+
  auto result = interpreter->run(*program);
 
  if (interpreter->exception()) {