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Diffstat (limited to 'src/script/parser/qscriptsyntaxchecker.cpp')
| -rw-r--r-- | src/script/parser/qscriptsyntaxchecker.cpp | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/src/script/parser/qscriptsyntaxchecker.cpp b/src/script/parser/qscriptsyntaxchecker.cpp new file mode 100644 index 000000000..ee91c529a --- /dev/null +++ b/src/script/parser/qscriptsyntaxchecker.cpp @@ -0,0 +1,214 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtScript module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at http://qt.nokia.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qscriptsyntaxchecker_p.h" + +#include "qscriptlexer_p.h" +#include "qscriptparser_p.h" + +QT_BEGIN_NAMESPACE + +namespace QScript { + + +SyntaxChecker::SyntaxChecker(): + tos(0), + stack_size(0), + state_stack(0) +{ +} + +SyntaxChecker::~SyntaxChecker() +{ + if (stack_size) { + qFree(state_stack); + } +} + +bool SyntaxChecker::automatic(QScript::Lexer *lexer, int token) const +{ + return token == T_RBRACE || token == 0 || lexer->prevTerminator(); +} + +SyntaxChecker::Result SyntaxChecker::checkSyntax(const QString &code) +{ + const int INITIAL_STATE = 0; + QScript::Lexer lexer (/*engine=*/ 0); + lexer.setCode(code, /*lineNo*/ 1); + + int yytoken = -1; + int saved_yytoken = -1; + QString error_message; + int error_lineno = -1; + int error_column = -1; + State checkerState = Valid; + + reallocateStack(); + + tos = 0; + state_stack[++tos] = INITIAL_STATE; + + while (true) + { + const int state = state_stack [tos]; + if (yytoken == -1 && - TERMINAL_COUNT != action_index [state]) + { + if (saved_yytoken == -1) + yytoken = lexer.lex(); + else + { + yytoken = saved_yytoken; + saved_yytoken = -1; + } + } + + int act = t_action (state, yytoken); + + if (act == ACCEPT_STATE) { + if (lexer.error() == QScript::Lexer::UnclosedComment) + checkerState = Intermediate; + else + checkerState = Valid; + break; + } else if (act > 0) { + if (++tos == stack_size) + reallocateStack(); + + state_stack [tos] = act; + yytoken = -1; + } + + else if (act < 0) + { + int r = - act - 1; + + tos -= rhs [r]; + act = state_stack [tos++]; + + if ((r == Q_SCRIPT_REGEXPLITERAL_RULE1) + || (r == Q_SCRIPT_REGEXPLITERAL_RULE2)) { + // Skip the rest of the RegExp literal + bool rx = lexer.scanRegExp(); + if (!rx) { + checkerState = Intermediate; + break; + } + } + + state_stack [tos] = nt_action (act, lhs [r] - TERMINAL_COUNT); + } + + else + { + if (saved_yytoken == -1 && automatic (&lexer, yytoken) && t_action (state, T_AUTOMATIC_SEMICOLON) > 0) + { + saved_yytoken = yytoken; + yytoken = T_SEMICOLON; + continue; + } + + else if ((state == INITIAL_STATE) && (yytoken == 0)) { + // accept empty input + yytoken = T_SEMICOLON; + continue; + } + + int ers = state; + int shifts = 0; + int reduces = 0; + int expected_tokens [3]; + for (int tk = 0; tk < TERMINAL_COUNT; ++tk) + { + int k = t_action (ers, tk); + + if (! k) + continue; + else if (k < 0) + ++reduces; + else if (spell [tk]) + { + if (shifts < 3) + expected_tokens [shifts] = tk; + ++shifts; + } + } + + error_message.clear (); + if (shifts && shifts < 3) + { + bool first = true; + + for (int s = 0; s < shifts; ++s) + { + if (first) + error_message += QLatin1String ("Expected "); + else + error_message += QLatin1String (", "); + + first = false; + error_message += QLatin1Char('`'); + error_message += QLatin1String (spell [expected_tokens [s]]); + error_message += QLatin1Char('\''); + } + } + + if (error_message.isEmpty()) + error_message = lexer.errorMessage(); + + error_lineno = lexer.startLineNo(); + error_column = lexer.startColumnNo(); + checkerState = Error; + break; + } + } + + if (checkerState == Error) { + if (lexer.error() == QScript::Lexer::UnclosedComment) + checkerState = Intermediate; + else if (yytoken == 0) + checkerState = Intermediate; + } + return Result(checkerState, error_lineno, error_column, error_message); +} + +} // namespace QScript + +QT_END_NAMESPACE |