jsparse.cpp

static JSBool
MatchOrInsertSemicolon(JSContext *cx, TokenStream *ts) 
{
    TokenKind tt = ts->peekTokenSameLine(TSF_OPERAND);
    if (tt == TOK_ERROR)                                                                                                                                                                          
        return JS_FALSE;
    if (tt != TOK_EOF && tt != TOK_EOL && tt != TOK_SEMI && tt != TOK_RC) {
        /* Advance the scanner for proper error location reporting. */
        ts->getToken(TSF_OPERAND);
        ReportCompileErrorNumber(cx, ts, NULL, JSREPORT_ERROR, JSMSG_SEMI_BEFORE_STMNT);
        return JS_FALSE;
    }    
    (void) ts->matchToken(TOK_SEMI);
    return JS_TRUE;
}

parser.cc

void Parser::ExpectSemicolon(bool* ok) {
  // Check for automatic semicolon insertion according to
  // the rules given in ECMA-262, section 7.9, page 21.
  Token::Value tok = peek();
  if (tok == Token::SEMICOLON) {                                                                                                                                                                  
    Next();
    return;
  }
  if (scanner().HasAnyLineTerminatorBeforeNext() ||
      tok == Token::RBRACE ||
      tok == Token::EOS) {
    return;
  }
  Expect(Token::SEMICOLON, ok); 
}