preprocessor.cpp

奇趣公司比较新的qt/emd版本

            else
#endif
                symbols += Symbol(lineNum, token, input, lexem-begin, data-lexem);
        }
    }
    symbols += Symbol(); // eof symbol
    return symbols;
}

void Preprocessor::substituteMacro(const MacroName &macro, Symbols &substituted, MacroSafeSet safeset)
{
    Symbols saveSymbols = symbols;
    int saveIndex = index;

    symbols = macros.value(macro).symbols;
    index = 0;

    safeset += macro;
    substituteUntilNewline(substituted, safeset);

    symbols = saveSymbols;
    index = saveIndex;
}



void Preprocessor::substituteUntilNewline(Symbols &substituted, MacroSafeSet safeset)
{
    while (hasNext()) {
        Token token = next();
        if (token == PP_IDENTIFIER) {
            MacroName macro = symbol();
            if (macros.contains(macro) && !safeset.contains(macro)) {
                substituteMacro(macro, substituted, safeset);
                continue;
            }
        } else if (token == PP_DEFINED) {
            test(PP_LPAREN);
            next(PP_IDENTIFIER);
            Symbol definedOrNotDefined = symbol();
            definedOrNotDefined.token = macros.contains(definedOrNotDefined)? PP_MOC_TRUE : PP_MOC_FALSE;
            substituted += definedOrNotDefined;
            test(PP_RPAREN);
            continue;
        } else if (token == PP_NEWLINE) {
            substituted += symbol();
            break;
        }
        substituted += symbol();
    }
}


class PP_Expression : public Parser
{
public:
    int value() { index = 0; return unary_expression_lookup() ?  conditional_expression() : 0; }

    int conditional_expression();
    int logical_OR_expression();
    int logical_AND_expression();
    int inclusive_OR_expression();
    int exclusive_OR_expression();
    int AND_expression();
    int equality_expression();
    int relational_expression();
    int shift_expression();
    int additive_expression();
    int multiplicative_expression();
    int unary_expression();
    bool unary_expression_lookup();
    int primary_expression();
    bool primary_expression_lookup();
};

int PP_Expression::conditional_expression()
{
    int value = logical_OR_expression();
    if (test(PP_QUESTION)) {
        int alt1 = conditional_expression();
        int alt2 = test(PP_COLON) ? conditional_expression() : 0;
        return value ? alt1 : alt2;
    }
    return value;
}

int PP_Expression::logical_OR_expression()
{
    int value = logical_AND_expression();
    if (test(PP_OROR))
        return logical_OR_expression() || value;
    return value;
}

int PP_Expression::logical_AND_expression()
{
    int value = inclusive_OR_expression();
    if (test(PP_ANDAND))
        return logical_AND_expression() && value;
    return value;
}

int PP_Expression::inclusive_OR_expression()
{
    int value = exclusive_OR_expression();
    if (test(PP_OR))
        return value | inclusive_OR_expression();
    return value;
}

int PP_Expression::exclusive_OR_expression()
{
    int value = AND_expression();
    if (test(PP_HAT))
        return value ^ exclusive_OR_expression();
    return value;
}

int PP_Expression::AND_expression()
{
    int value = equality_expression();
    if (test(PP_AND))
        return value & AND_expression();
    return value;
}

int PP_Expression::equality_expression()
{
    int value = relational_expression();
    switch (next()) {
    case PP_EQEQ:
        return value == equality_expression();
    case PP_NE:
        return value != equality_expression();
    default:
        prev();
        return value;
    }
}

int PP_Expression::relational_expression()
{
    int value = shift_expression();
    switch (next()) {
    case PP_LANGLE:
        return value < relational_expression();
    case PP_RANGLE:
        return value > relational_expression();
    case PP_LE:
        return value <= relational_expression();
    case PP_GE:
        return value >= relational_expression();
    default:
        prev();
        return value;
    }
}

int PP_Expression::shift_expression()
{
    int value = additive_expression();
    switch (next()) {
    case PP_LTLT:
        return value << shift_expression();
    case PP_GTGT:
        return value >> shift_expression();
    default:
        prev();
        return value;
    }
}

int PP_Expression::additive_expression()
{
    int value = multiplicative_expression();
    switch (next()) {
    case PP_PLUS:
        return value + additive_expression();
    case PP_MINUS:
        return value - additive_expression();
    default:
        prev();
        return value;
    }
}

int PP_Expression::multiplicative_expression()
{
    int value = unary_expression();
    switch (next()) {
    case PP_STAR:
        return value * multiplicative_expression();
    case PP_PERCENT:
    {
        int remainder = multiplicative_expression();
        return remainder ? value % remainder : 0;
    }
    case PP_SLASH:
    {
        int div = multiplicative_expression();
        return div ? value / div : 0;
    }
    default:
        prev();
        return value;
    };
}

int PP_Expression::unary_expression()
{
    switch (next()) {
    case PP_PLUS:
        return unary_expression();
    case PP_MINUS:
        return -unary_expression();
    case PP_NOT:
        return !unary_expression();
    case PP_TILDE:
        return ~unary_expression();
    case PP_MOC_TRUE:
        return 1;
    case PP_MOC_FALSE:
        return 0;
    default:
        prev();
        return primary_expression();
    }
}

bool PP_Expression::unary_expression_lookup()
{
    Token t = lookup();
    return (primary_expression_lookup()
            || t == PP_PLUS
            || t == PP_MINUS
            || t == PP_NOT
            || t == PP_TILDE
            || t == PP_DEFINED);
}

int PP_Expression::primary_expression()
{
    int value;
    if (test(PP_LPAREN)) {
        value = conditional_expression();
        test(PP_RPAREN);
    } else {
        next();
        value = lexem().toInt(0, 0);
    }
    return value;
}

bool PP_Expression::primary_expression_lookup()
{
    Token t = lookup();
    return (t == PP_IDENTIFIER
            || t == PP_INTEGER_LITERAL
            || t == PP_FLOATING_LITERAL
            || t == PP_MOC_TRUE
            || t == PP_MOC_FALSE
            || t == PP_LPAREN);
}

int Preprocessor::evaluateCondition()
{
    PP_Expression expression;
    expression.currentFilenames = currentFilenames;

    substituteUntilNewline(expression.symbols);

    return expression.value();
}

void Preprocessor::preprocess(const QByteArray &filename, Symbols &preprocessed)
{
    currentFilenames.push(filename);
    preprocessed.reserve(preprocessed.size() + symbols.size());
    while (hasNext()) {
        Token token = next();

        switch (token) {
        case PP_INCLUDE:
        {
            int lineNum = symbol().lineNum;
            QByteArray include;
            bool local = false;
            if (test(PP_STRING_LITERAL)) {
                local = lexem().startsWith('\"');
                include = unquotedLexem();
            } else
                continue;
            until(PP_NEWLINE);

            // #### stringery
            QFileInfo fi;
            if (local)
                fi.setFile(QFileInfo(QString::fromLocal8Bit(filename)).dir(), QString::fromLocal8Bit(include));
            for (int j = 0; j < Preprocessor::includes.size() && !fi.exists(); ++j) {
                const IncludePath &p = Preprocessor::includes.at(j);
                if (p.isFrameworkPath) {
                    const int slashPos = include.indexOf('/');
                    if (slashPos == -1)
                        continue;
                    QByteArray frameworkCandidate = include.left(slashPos);
                    frameworkCandidate.append(".framework/Headers/");
                    fi.setFile(QString::fromLocal8Bit(p.path + "/" + frameworkCandidate), QString::fromLocal8Bit(include.mid(slashPos + 1)));
                } else {
                    fi.setFile(QString::fromLocal8Bit(p.path), QString::fromLocal8Bit(include));
                }
            }

            if (!fi.exists() || fi.isDir())
                continue;
            include = fi.filePath().toLocal8Bit();

            if (Preprocessor::preprocessedIncludes.contains(include))
                continue;
            Preprocessor::preprocessedIncludes.insert(include);

            QFile file(QString::fromLocal8Bit(include));
            if (!file.open(QFile::ReadOnly))
                continue;

            QByteArray input = file.readAll();
            file.close();
            if (input.isEmpty())
                continue;

            Symbols saveSymbols = symbols;
            int saveIndex = index;

            // phase 1: get rid of backslash-newlines
            input = cleaned(input);

            // phase 2: tokenize for the preprocessor
            symbols = tokenize(input);
            input.clear();

            index = 0;

            // phase 3: preprocess conditions and substitute macros
            preprocessed += Symbol(0, MOC_INCLUDE_BEGIN, include);
            preprocess(include, preprocessed);
            preprocessed += Symbol(lineNum, MOC_INCLUDE_END, include);

            symbols = saveSymbols;
            index = saveIndex;
            continue;
        }
        case PP_DEFINE:
        {
            next(IDENTIFIER);
            QByteArray name = lexem();
            int start = index;
            until(PP_NEWLINE);
            Macro macro;
            macro.symbols.reserve(index - start - 1);
            for (int i = start; i < index - 1; ++i)
                macro.symbols += symbols.at(i);
            macros.insert(name, macro);
            continue;
        }
        case PP_UNDEF: {
            next(IDENTIFIER);
            QByteArray name = lexem();
            until(PP_NEWLINE);
            macros.remove(name);
            continue;
        }
        case PP_IDENTIFIER:
        {
//             if (macros.contains(symbol()))
//                 ;
        }
            // we _could_ easily substitute macros by the following
            // four lines, but we choose not to.
            /*
            if (macros.contains(sym.lexem())) {
                preprocessed += substitute(macros, symbols, i);
                continue;
            }
            */
            break;
        case PP_HASH:
            until(PP_NEWLINE);
            continue; // skip unknown preprocessor statement
        case PP_IFDEF:
        case PP_IFNDEF:
        case PP_IF:
            while (!evaluateCondition()) {
                if (!skipBranch())
                    break;
                if (test(PP_ELIF)) {
                } else {
                    until(PP_NEWLINE);
                    break;
                }
            }
            continue;
        case PP_ELIF:
        case PP_ELSE:
            skipUntilEndif();
            // fall through
        case PP_ENDIF:
            until(PP_NEWLINE);
            continue;
        case SIGNALS:
        case SLOTS: {
            Symbol sym = symbol();
            if (macros.contains("QT_NO_KEYWORDS"))
                sym.token = IDENTIFIER;
            else
                sym.token = (token == SIGNALS ? Q_SIGNALS_TOKEN : Q_SLOTS_TOKEN);
            preprocessed += sym;
        } continue;
        default:
            break;
        }
        preprocessed += symbol();
    }

    currentFilenames.pop();
}

Symbols Preprocessor::preprocessed(const QByteArray &filename, FILE *file)
{
    QFile qfile;
    qfile.open(file, QFile::ReadOnly);
    QByteArray input = qfile.readAll();
    if (input.isEmpty())
        return symbols;
    
    // phase 1: get rid of backslash-newlines
    input = cleaned(input);

    // phase 2: tokenize for the preprocessor
    symbols = tokenize(input);

#if 0
    for (int j = 0; j < symbols.size(); ++j)
        fprintf(stderr, "line %d: %s(%s)\n",
               symbols[j].lineNum,
               symbols[j].lexem().constData(),
               tokenTypeName(symbols[j].token));
#endif

    // phase 3: preprocess conditions and substitute macros
    Symbols result;
    preprocess(filename, result);

#if 0
    for (int j = 0; j < result.size(); ++j)
        fprintf(stderr, "line %d: %s(%s)\n",
               result[j].lineNum,
               result[j].lexem().constData(),
               tokenTypeName(result[j].token));
#endif

    return result;
}

void Preprocessor::until(Token t)
{
    while(hasNext() && next() != t)
        ;
}