cppcodeformatter.cpp

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**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of Qt Creator.
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** 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
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#include "cppcodeformatter.h"

#include <texteditor/basetextdocumentlayout.h>
#include <cplusplus/Lexer.h>

#include <utils/qtcassert.h>

#include <QDebug>
#include <QMetaEnum>
#include <QTextDocument>
#include <QTextBlock>

using namespace CPlusPlus;
using namespace CppTools;
using namespace TextEditor;
using namespace CppTools::Internal;

CodeFormatter::BlockData::BlockData()
    : m_blockRevision(-1)
{
}

CodeFormatter::CodeFormatter()
    : m_indentDepth(0)
    , m_paddingDepth(0)
    , m_tabSize(4)
{
}

CodeFormatter::~CodeFormatter()
{
}

void CodeFormatter::setTabSize(int tabSize)
{
    m_tabSize = tabSize;
}

void CodeFormatter::recalculateStateAfter(const QTextBlock &block)
{
    restoreCurrentState(block.previous());

    bool endedJoined = false;
    const int lexerState = tokenizeBlock(block, &endedJoined);
    m_tokenIndex = 0;
    m_newStates.clear();

    if (tokenAt(0).kind() == T_POUND) {
        enter(cpp_macro_start);
        m_tokenIndex = 1;
    }

    for (; m_tokenIndex < m_tokens.size(); ) {
        m_currentToken = tokenAt(m_tokenIndex);
        const int kind = m_currentToken.kind();

        switch (m_currentState.top().type) {
        case topmost_intro:
            tryDeclaration();
            break;

        case namespace_start:
            switch (kind) {
            case T_LBRACE:      enter(namespace_open); break;
            case T_SEMICOLON:
            case T_RBRACE:      leave(); break;
            } break;

        case namespace_open:
            if (tryDeclaration())
                break;
            switch (kind) {
            case T_RBRACE:      leave(); continue; // always nested in namespace_start
            } break;

        case extern_start:
            switch (kind) {
            case T_STRING_LITERAL: break; // continue looking for the lbrace
            case T_LBRACE:      enter(extern_open); break;
            default:            leave(); continue;
            } break;

        case extern_open:
            if (tryDeclaration())
                break;
            switch (kind) {
            case T_RBRACE:      leave(); leave(); break; // always nested in extern_start
            } break;

        case class_start:
            switch (kind) {
            case T_SEMICOLON:   leave(); break;
            case T_LPAREN:      turnInto(declaration_start); continue; // "struct Foo bar() {"
            case T_LBRACE:      enter(class_open); break;
            } break;

        case class_open:
            if (tryDeclaration())
                break;
            switch (kind) {
            case T_RBRACE:      leave(); continue; // always nested in class_start
            } break;

        case access_specifier_start:
            switch (kind) {
            case T_COLON:       leave(); break;
            } break;

        case enum_start:
            switch (kind) {
            case T_SEMICOLON:   leave(); break;
            case T_LPAREN:      turnInto(declaration_start); continue; // "enum Foo bar() {"
            case T_LBRACE:      enter(enum_open); break;
            } break;

        case enum_open:
            switch (kind) {
            case T_RBRACE:      leave(); continue; // always nested in enum_start
            case T_LBRACE:      enter(brace_list_open); break;
            } break;

        case brace_list_open:
            switch (kind) {
            case T_RBRACE:      leave(); break;
            case T_LBRACE:      enter(brace_list_open); break;
            } break;

        case using_start:
            switch (kind) {
            case T_SEMICOLON:   leave(); break;
            } break;

        case template_start:
            switch (kind) {
            case T_LESS:        turnInto(template_param); break;
            } break;

        case template_param:
            switch (kind) {
            case T_LESS:        enter(template_param); break;
            case T_GREATER:     leave(); break;
            } break;

        case operator_declaration:
            switch (kind) {
            case T_LPAREN:      break;
            default:            leave(); break;
            } break;

        case declaration_start:
            switch (kind) {
            case T_RBRACE:      leave(true); continue;
            case T_SEMICOLON:   leave(true); break;
            case T_EQUAL:       enter(assign_open_or_initializer); break;
            case T_LBRACE:      enter(defun_open); break;
            case T_COLON:       enter(member_init_open); enter(member_init_expected); break;
            case T_OPERATOR:    enter(operator_declaration); break;
            default:            tryExpression(true); break;
            } break;

        case assign_open_or_initializer:
            switch (kind) {
            case T_LBRACE:      enter(brace_list_open); break;
            case T_RBRACE:      leave(true); continue;
            case T_SEMICOLON:   leave(); continue;
            case T_RPAREN:      leave(); continue;
            case T_COMMA:       leave(); continue;
            default:            enter(assign_open); continue;
            } break;

        case expression:
            switch (kind) {
            case T_RBRACE:      leave(true); continue;
            case T_SEMICOLON:   leave(); continue;
            case T_LBRACE:
            case T_COLON:
                if (m_currentState.at(m_currentState.size() - 2).type == declaration_start) {
                    // oops, the expression was a function declaration argument list, hand lbrace/colon to declaration_start
                    leave();
                    continue;
                } else {
                    turnInto(substatement_open);
                }
                break;
            default:            tryExpression(); break;
            } break;

        case assign_open:
            switch (kind) {
            case T_RBRACE:      leave(true); continue;
            case T_SEMICOLON:   leave(); continue;
            case T_RPAREN:      leave(); continue;
            case T_COMMA:       leave(); continue;
            default:            tryExpression(); break;
            } break;

        case lambda_instroducer_or_subscribtion:
            switch (kind) {
            case T_RBRACKET:    turnInto(lambda_declarator_expected); break; // we can't determine exact kind of expression. Try again
            case T_COMMA:
            case T_EQUAL:       turnInto(lambda_instroducer); break;              // ',' or '=' inside brackets can be only whithin lambda capture list
            case T_IDENTIFIER:          // '&', id, 'this' are allowed both in the capture list and subscribtion
            case T_AMPER:
            case T_THIS:        break;
            default:            leave(); leave(); tryExpression(m_currentState.at(m_currentState.size() - 1).type == declaration_start); break;
                                        // any other symbol allowed only in subscribtion operator
            } break;

        case lambda_declarator_expected:
            switch (kind) {
            case T_LPAREN:      turnInto(lambda_declarator_or_expression); break; // '(' just after ']'. We can't make decisioin here
            case T_LBRACE:      turnInto(substatement_open); break; // '{' just after ']' opens a lambda-compound statement
            default:
                if (m_currentState.size() >= 3 && m_currentState.at(m_currentState.size() - 3).type == declaration_start)
                    leave();

                leave();
                continue;
            } break;

        case lambda_instroducer:
            switch (kind) {
            case T_RBRACKET:    turnInto(lambda_declarator); break;
            } break;

        case lambda_declarator_or_expression:
            switch (kind) {
            case T_LBRACE:      turnInto(substatement_open); /*tryStatement();*/ break;
            case T_RPAREN:      turnInto(lambda_statement_expected); break;
            case T_IDENTIFIER:
            case T_SEMICOLON:   leave(); continue;
            default:
                if (tryDeclaration()) {// We found the declaration within '()' so it is lambda declarator
                    leave();
                    turnInto(lambda_declarator);
                    break;
                } else {
                    turnInto(expression);
                    enter(arglist_open);
                    continue;
                }
            } break;

        case lambda_statement_expected:
            switch (kind) {
            case T_LBRACE:      turnInto(substatement_open); /*tryStatement()*/; break;
            case T_NOEXCEPT:    // 'noexcept', 'decltype' and 'mutable' are only part of lambda declarator
            case T_DECLTYPE:
            case T_MUTABLE:     turnInto(lambda_declarator); break;
            case T_RBRACKET:    // '[', ']' and '->' can be part of lambda declarator
            case T_LBRACKET:
            case T_ARROW:       break;
            default:            leave(); continue;
            } break;

        case lambda_declarator:
            switch (kind) {
            case T_LBRACE:      turnInto(substatement_open); /*tryStatement()*/; break;
            } break;

        case arglist_open:
            switch (kind) {
            case T_SEMICOLON:   leave(true); break;
            case T_LBRACE:      enter(brace_list_open); break;
            case T_RBRACE:      leave(true); continue;
            case T_RPAREN:      leave(); break;
            default:            tryExpression(); break;
            } break;

        case braceinit_open:
            switch (kind) {
            case T_RBRACE:      leave(); break;
            case T_RPAREN:      leave(); continue; // recover?
            default:            tryExpression(); break;
            } break;

        case ternary_op:
            switch (kind) {
            case T_RPAREN:
            case T_COMMA:
            case T_SEMICOLON:   leave(); continue; // always nested, propagate
            default:            tryExpression(); break;
            } break;

        case stream_op:
        case stream_op_cont:
            switch (kind) {
            case T_LESS_LESS:
            case T_GREATER_GREATER:
                if (m_currentState.top().type == stream_op)
                    enter(stream_op_cont);
                else // stream_op_cont already
                    turnInto(stream_op_cont);
                break;
            case T_RPAREN:
            case T_COMMA:
            case T_SEMICOLON:   leave(); continue; // always nested, propagate
            default:            tryExpression(); break;
            } break;

        case member_init_open:
            switch (kind) {
            case T_LBRACE:      turnInto(defun_open); break;
            case T_COMMA:       enter(member_init_expected); break;
            case T_SEMICOLON:   leave(); continue; // try to recover
            } break;

        case member_init_expected:
            switch (kind) {
            case T_IDENTIFIER:  turnInto(member_init); break;
            case T_LBRACE:
            case T_SEMICOLON:   leave(); continue; // try to recover
            } break;

        case member_init:
            switch (kind) {
            case T_LBRACE:
            case T_LPAREN:      enter(member_init_nest_open); break;
            case T_RBRACE:
            case T_RPAREN:      leave(); break;
            case T_SEMICOLON:   leave(); continue; // try to recover
            } break;

        case member_init_nest_open:
            switch (kind) {
            case T_RBRACE:
            case T_RPAREN:      leave(); continue;
            case T_SEMICOLON:   leave(); continue; // try to recover
            default:            tryExpression(); break;
            } break;

        case defun_open:
            if (tryStatement())
                break;
            switch (kind) {
            case T_RBRACE:      leave(); leave(); break; // always nested in declaration_start
            } break;

        case switch_statement:
        case statement_with_condition:
        case if_statement:
            switch (kind) {
            case T_LPAREN:      enter(condition_open); break;
            default:            leave(true); continue;
            } break;

        case maybe_else:
            if (m_currentToken.isComment()) {
                break;
            } else if (kind == T_ELSE) {
                turnInto(else_clause);
                enter(substatement);
                break;
            } else {
                leave(true);
                continue;
            }

        case else_clause:
            // ### shouldn't happen
            dump();
            QTC_CHECK(false);
            leave(true);
            break;

        case do_statement:
            // ### shouldn't happen
            dump();
            QTC_CHECK(false);
            leave(true);
            break;

        case return_statement:
            switch (kind) {
            case T_RBRACE:      leave(true); continue;
            case T_SEMICOLON:   leave(true); break;
            } break;

        case substatement:
            // prefer substatement_open over block_open
            if (kind != T_LBRACE && tryStatement())
                break;
            switch (kind) {
            case T_LBRACE:      turnInto(substatement_open); break;
            case T_SEMICOLON:   leave(true); break;
            case T_RBRACE:      leave(true); continue;
            } break;

        case for_statement:
            switch (kind) {
            case T_LPAREN:      enter(for_statement_paren_open); break;
            default:            leave(true); continue;
            } break;

        case for_statement_paren_open:
            enter(for_statement_init); continue;

        case for_statement_init:
            switch (kind) {
            case T_SEMICOLON:   turnInto(for_statement_condition); break;
            case T_LPAREN:      enter(condition_paren_open); break;
            case T_RPAREN:      turnInto(for_statement_expression); continue;
            } break;

        case for_statement_condition:
            switch (kind) {
            case T_SEMICOLON:   turnInto(for_statement_expression); break;
            case T_LPAREN:      enter(condition_paren_open); break;
            case T_RPAREN:      turnInto(for_statement_expression); continue;
            } break;

        case for_statement_expression:
            switch (kind) {
            case T_RPAREN:      leave(); turnInto(substatement); break;
            case T_LPAREN:      enter(condition_paren_open); break;
            } break;

        case case_start:
            switch (kind) {
            case T_COLON:       turnInto(case_cont); break;
            } break;

        case case_cont:
            if (kind != T_CASE && kind != T_DEFAULT && tryStatement())
                break;
            switch (kind) {
            case T_RBRACE:      leave(); continue;
            case T_DEFAULT:
            case T_CASE:        leave(); continue;
            } break;

        case substatement_open:
            if (tryStatement())
                break;
            switch (kind) {
            case T_RBRACE:      leave(true); break;
            } break;

        case condition_open:
            switch (kind) {
            case T_RPAREN:      turnInto(substatement); break;
            case T_LPAREN:      enter(condition_paren_open); break;
            } break;

        case block_open:
            if (tryStatement())
                break;
            switch (kind) {
            case T_RBRACE:      leave(true); break;
            } break;

        // paren nesting
        case condition_paren_open:
            switch (kind) {
            case T_RPAREN:      leave(); break;
            case T_LPAREN:      enter(condition_paren_open); break;
            } break;

        case qt_like_macro:
            switch (kind) {
            case T_LPAREN:      enter(arglist_open); break;
            case T_SEMICOLON:   leave(true); break;
            default:            leave(); continue;
            } break;

        case label:
            switch (kind) {
            case T_COLON:       leave(); break;
            default:            leave(); continue; // shouldn't happen
            } break;

        case multiline_comment_start:
        case multiline_comment_cont:
            if (kind != T_COMMENT && kind != T_DOXY_COMMENT) {
                leave();
                continue;
            } else if (m_tokenIndex == m_tokens.size() - 1
                    && lexerState == Lexer::State_Default) {
                leave();
            } else if (m_tokenIndex == 0 && m_currentToken.isComment()) {
                // to allow enter/leave to update the indentDepth
                turnInto(multiline_comment_cont);
            }
            break;

        case cpp_macro_start: {
            const int size = m_currentState.size();

            int previousMarker = -1;
            int previousPreviousMarker = -1;
            for (int i = size - 1; i >= 0; --i) {
                if (m_currentState.at(i).type == cpp_macro_conditional) {
                    if (previousMarker == -1) {
                        previousMarker = i;
                    } else {
                        previousPreviousMarker = i;
                        break;
                    }
                }
            }

            QStringRef tokenText = currentTokenText();
            if (tokenText == QLatin1String("ifdef")
                    || tokenText == QLatin1String("if")
                    || tokenText == QLatin1String("ifndef")) {
                enter(cpp_macro_conditional);
                // copy everything right of previousMarker, excluding cpp_macro_conditional
                for (int i = previousMarker + 1; i < size; ++i)
                    m_currentState += m_currentState.at(i);
            }
            if (previousMarker != -1) {
                if (tokenText == QLatin1String("endif")) {
                    QStack<State>::iterator begin = m_currentState.begin() + previousPreviousMarker + 1;
                    QStack<State>::iterator end = m_currentState.begin() + previousMarker + 1;
                    m_currentState.erase(begin, end);
                } else if (tokenText == QLatin1String("else")
                        || tokenText == QLatin1String("elif")) {
                    m_currentState.resize(previousMarker + 1);
                    for (int i = previousPreviousMarker + 1; i < previousMarker; ++i)
                        m_currentState += m_currentState.at(i);
                }
            }

            turnInto(cpp_macro);
            break;
        }

        case cpp_macro:
        case cpp_macro_cont:
            break;

        default:
            qWarning() << "Unhandled state" << m_currentState.top().type;
            break;

        } // end of state switch

        ++m_tokenIndex;
    }

    int topState = m_currentState.top().type;

    if (topState != multiline_comment_start
            && topState != multiline_comment_cont
            && (lexerState == Lexer::State_MultiLineComment
                || lexerState == Lexer::State_MultiLineDoxyComment)) {
        enter(multiline_comment_start);
    }

    if (topState == qt_like_macro)
        leave(true);

    if ((topState == cpp_macro_cont
            || topState == cpp_macro) && !endedJoined)
        leave();

    if (topState == cpp_macro && endedJoined)
        turnInto(cpp_macro_cont);

    saveCurrentState(block);
}

void CodeFormatter::indentFor(const QTextBlock &block, int *indent, int *padding)
{
//    qDebug() << "indenting for" << block.blockNumber() + 1;

    restoreCurrentState(block.previous());
    correctIndentation(block);
    *indent = m_indentDepth;
    *padding = m_paddingDepth;
}

void CodeFormatter::indentForNewLineAfter(const QTextBlock &block, int *indent, int *padding)
{
    restoreCurrentState(block);
    *indent = m_indentDepth;
    *padding = m_paddingDepth;

    int lexerState = loadLexerState(block);
    m_tokens.clear();
    m_currentLine.clear();
    adjustIndent(m_tokens, lexerState, indent, padding);
}

void CodeFormatter::updateStateUntil(const QTextBlock &endBlock)
{
    QStack<State> previousState = initialState();
    QTextBlock it = endBlock.document()->firstBlock();

    // find the first block that needs recalculation
    for (; it.isValid() && it != endBlock; it = it.next()) {
        BlockData blockData;
        if (!loadBlockData(it, &blockData))
            break;
        if (blockData.m_blockRevision != it.revision())
            break;
        if (previousState.isEmpty() || blockData.m_beginState.isEmpty()
                || previousState != blockData.m_beginState)
            break;
        if (loadLexerState(it) == -1)
            break;

        previousState = blockData.m_endState;
    }

    if (it == endBlock)
        return;

    // update everthing until endBlock
    for (; it.isValid() && it != endBlock; it = it.next()) {
        recalculateStateAfter(it);
    }

    // invalidate everything below by marking the state in endBlock as invalid
    if (it.isValid()) {
        BlockData invalidBlockData;
        saveBlockData(&it, invalidBlockData);
    }
}

void CodeFormatter::updateLineStateChange(const QTextBlock &block)
{
    if (!block.isValid())
        return;

    BlockData blockData;
    if (loadBlockData(block, &blockData) && blockData.m_blockRevision == block.revision())
        return;

    recalculateStateAfter(block);

    // invalidate everything below by marking the next block's state as invalid
    QTextBlock next = block.next();
    if (!next.isValid())
        return;

    saveBlockData(&next, BlockData());
}

CodeFormatter::State CodeFormatter::state(int belowTop) const
{
    if (belowTop < m_currentState.size())
        return m_currentState.at(m_currentState.size() - 1 - belowTop);
    else
        return State();
}

const QVector<CodeFormatter::State> &CodeFormatter::newStatesThisLine() const
{
    return m_newStates;
}

int CodeFormatter::tokenIndex() const
{
    return m_tokenIndex;
}

int CodeFormatter::tokenCount() const
{
    return m_tokens.size();
}

const CPlusPlus::Token &CodeFormatter::currentToken() const
{
    return m_currentToken;
}

void CodeFormatter::invalidateCache(QTextDocument *document)
{
    if (!document)
        return;

    BlockData invalidBlockData;
    QTextBlock it = document->firstBlock();
    for (; it.isValid(); it = it.next()) {
        saveBlockData(&it, invalidBlockData);
    }
}

void CodeFormatter::enter(int newState)
{
    int savedIndentDepth = m_indentDepth;
    int savedPaddingDepth = m_paddingDepth;
    onEnter(newState, &m_indentDepth, &savedIndentDepth, &m_paddingDepth, &savedPaddingDepth);
    State s(newState, savedIndentDepth, savedPaddingDepth);
    m_currentState.push(s);
    m_newStates.push(s);
}

void CodeFormatter::leave(bool statementDone)
{
    QTC_ASSERT(m_currentState.size() > 1, return);
    if (m_currentState.top().type == topmost_intro)
        return;

    if (m_newStates.size() > 0)
        m_newStates.pop();

    // restore indent depth
    State poppedState = m_currentState.pop();
    m_indentDepth = poppedState.savedIndentDepth;
    m_paddingDepth = poppedState.savedPaddingDepth;

    int topState = m_currentState.top().type;

    // does it suffice to check if token is T_SEMICOLON or T_RBRACE?
    // maybe distinction between leave and turnInto?
    if (statementDone) {
        if (topState == substatement
                || topState == statement_with_condition
                || topState == for_statement
                || topState == switch_statement
                || topState == do_statement) {
            leave(true);
        } else if (topState == if_statement) {
            if (poppedState.type != maybe_else)
                enter(maybe_else);
            else
                leave(true);
        } else if (topState == else_clause) {
            // leave the else *and* the surrounding if, to prevent another else
            leave();
            leave(true);
        }
    }
}

void CodeFormatter::correctIndentation(const QTextBlock &block)
{
    const int lexerState = tokenizeBlock(block);
    QTC_ASSERT(m_currentState.size() >= 1, return);

    adjustIndent(m_tokens, lexerState, &m_indentDepth, &m_paddingDepth);
}

bool CodeFormatter::tryExpression(bool alsoExpression)
{
    int newState = -1;

    const int kind = m_currentToken.kind();
    switch (kind) {
    case T_LPAREN:          newState = arglist_open; break;
    case T_QUESTION:        newState = ternary_op; break;
    case T_LBRACE:          newState = braceinit_open; break;

    case T_EQUAL:
    case T_AMPER_EQUAL:
    case T_CARET_EQUAL:
    case T_SLASH_EQUAL:
    case T_EXCLAIM_EQUAL:
    case T_GREATER_GREATER_EQUAL:
    case T_LESS_LESS_EQUAL:
    case T_MINUS_EQUAL:
    case T_PERCENT_EQUAL:
    case T_PIPE_EQUAL:
    case T_PLUS_EQUAL:
    case T_STAR_EQUAL:
    case T_TILDE_EQUAL:
        newState = assign_open;
        break;

    case T_LESS_LESS:
    case T_GREATER_GREATER:
        newState = stream_op;
        for (int i = m_currentState.size() - 1; i >= 0; --i) {
            const int type = m_currentState.at(i).type;
            if (type == arglist_open) { // likely a left-shift instead
                newState = -1;
                break;
            }
            if (type == topmost_intro
                    || type == substatement_open
                    || type == defun_open
                    || type == namespace_open
                    || type == extern_open
                    || type == class_open
                    || type == brace_list_open) {
                break;
            }
        }
        break;
    case T_LBRACKET:
        newState = lambda_instroducer_or_subscribtion;
        break;
    }

    if (newState != -1) {
        if (alsoExpression)
            enter(expression);
        enter(newState);
        return true;
    }

    return false;
}

bool CodeFormatter::tryDeclaration()
{
    const int kind = m_currentToken.kind();
    switch (kind) {
    case T_Q_ENUMS:
    case T_Q_PROPERTY:
    case T_Q_PRIVATE_PROPERTY:
    case T_Q_FLAGS:
    case T_Q_GADGET:
    case T_Q_OBJECT:
    case T_Q_INTERFACES:
    case T_Q_DECLARE_INTERFACE:
    case T_Q_PRIVATE_SLOT:
        enter(qt_like_macro);
        return true;
    case T_IDENTIFIER:
        if (m_tokenIndex == 0) {
            const QStringRef tokenText = currentTokenText();
            if (tokenText.startsWith(QLatin1String("Q_"))
                    || tokenText.startsWith(QLatin1String("QT_"))
                    || tokenText.startsWith(QLatin1String("QML_"))
                    || tokenText.startsWith(QLatin1String("QDOC_"))) {
                enter(qt_like_macro);
                return true;
            }
            if (m_tokens.size() > 1 && m_tokens.at(1).kind() == T_COLON) {
                enter(label);
                return true;
            }
        }
        // fallthrough
    case T_CHAR:
    case T_CHAR16_T:
    case T_CHAR32_T:
    case T_WCHAR_T:
    case T_BOOL:
    case T_SHORT:
    case T_INT:
    case T_LONG:
    case T_SIGNED:
    case T_UNSIGNED:
    case T_FLOAT:
    case T_DOUBLE:
    case T_VOID:
    case T_AUTO:
    case T___TYPEOF__:
    case T___ATTRIBUTE__:
    case T_STATIC:
    case T_FRIEND:
    case T_CONST:
    case T_VOLATILE:
    case T_INLINE:
        enter(declaration_start);
        return true;

    case T_TEMPLATE:
        enter(template_start);
        return true;

    case T_NAMESPACE:
        enter(namespace_start);
        return true;

    case T_EXTERN:
        enter(extern_start);
        return true;

    case T_STRUCT:
    case T_UNION:
    case T_CLASS:
        enter(class_start);
        return true;

    case T_ENUM:
        enter(enum_start);
        return true;

    case T_USING:
        enter(using_start);
        return true;

    case T_PUBLIC:
    case T_PRIVATE:
    case T_PROTECTED:
    case T_Q_SIGNALS:
        if (m_currentState.top().type == class_open) {
            enter(access_specifier_start);
            return true;
        }
        return false;

    default:
        return false;
    }
}

bool CodeFormatter::tryStatement()
{
    const int kind = m_currentToken.kind();
    if (tryDeclaration())
        return true;
    switch (kind) {
    case T_RETURN:
        enter(return_statement);
        enter(expression);
        return true;
    case T_FOR:
        enter(for_statement);
        return true;
    case T_SWITCH:
        enter(switch_statement);
        return true;
    case T_IF:
        enter(if_statement);
        return true;
    case T_WHILE:
    case T_Q_FOREACH:
        enter(statement_with_condition);
        return true;
    case T_DO:
        enter(do_statement);
        enter(substatement);
        return true;
    case T_CASE:
    case T_DEFAULT:
        enter(case_start);
        return true;
    case T_LBRACE:
        enter(block_open);
        return true;
    default:
        return false;
    }
}

bool CodeFormatter::isBracelessState(int type) const
{
    return type == substatement
        || type == if_statement
        || type == else_clause
        || type == statement_with_condition
        || type == for_statement
        || type == do_statement;
}

const Token &CodeFormatter::tokenAt(int idx) const
{
    static const Token empty;
    if (idx < 0 || idx >= m_tokens.size())
        return empty;
    else
        return m_tokens.at(idx);
}

int CodeFormatter::column(int index) const
{
    int col = 0;
    if (index > m_currentLine.length())
        index = m_currentLine.length();

    const QChar tab = QLatin1Char('\t');

    for (int i = 0; i < index; i++) {
        if (m_currentLine[i] == tab)
            col = ((col / m_tabSize) + 1) * m_tabSize;
        else
            col++;
    }
    return col;
}

QStringRef CodeFormatter::currentTokenText() const
{
    return m_currentLine.midRef(m_currentToken.begin(), m_currentToken.length());
}