OgreGLSLESPreprocessor.h

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/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2013 Torus Knot Software Ltd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
-----------------------------------------------------------------------------
*/

#ifndef __OGRE_CPREPROCESSOR_H__
#define __OGRE_CPREPROCESSOR_H__

#include <string.h>
#include <stdlib.h>

namespace Ogre {

class CPreprocessor
{
    class Token
    {
    public:
        enum Kind
        {
            TK_EOS,          // End of input stream
            TK_ERROR,        // An error has been encountered
            TK_WHITESPACE,   // A whitespace span (but not newline)
            TK_NEWLINE,      // A single newline (CR & LF)
            TK_LINECONT,     // Line continuation ('\' followed by LF)
            TK_NUMBER,       // A number
            TK_KEYWORD,      // A keyword
            TK_PUNCTUATION,  // A punctuation character
            TK_DIRECTIVE,    // A preprocessor directive
            TK_STRING,       // A string
            TK_COMMENT,      // A block comment
            TK_LINECOMMENT,  // A line comment
            TK_TEXT          // An unparsed text (cannot be returned from GetToken())
        };

        Kind Type;
        mutable size_t Allocated;
        union
        {
            const char *String;
            char *Buffer;
        };
        size_t Length;

        Token () : Allocated (0), String (NULL)
        { }

        Token (Kind iType) : Type (iType), Allocated (0), String (NULL)
        { }

        Token (Kind iType, const char *iString, size_t iLength) :
            Type (iType), Allocated (0), String (iString), Length (iLength)
        { }

        Token (const Token &iOther)
        {
            Type = iOther.Type;
            Allocated = iOther.Allocated;
            iOther.Allocated = 0; // !!! not quite correct but effective
            String = iOther.String;
            Length = iOther.Length;
        }

        ~Token ()
        { if (Allocated) free (Buffer); }

        Token &operator = (const Token &iOther)
        {
            if (Allocated) free (Buffer);
            Type = iOther.Type;
            Allocated = iOther.Allocated;
            iOther.Allocated = 0; // !!! not quite correct but effective
            String = iOther.String;
            Length = iOther.Length;
            return *this;
        }

        void Append (const char *iString, size_t iLength);

        void Append (const Token &iOther);

        void AppendNL (int iCount);

        int CountNL ();

        bool GetValue (long &oValue) const;

        void SetValue (long iValue);

        bool operator == (const Token &iOther)
        {
            if (iOther.Length != Length)
                return false;
            return (memcmp (String, iOther.String, Length) == 0);
        }
    };

    class Macro
    {
    public:
        Token Name;
        int NumArgs;
        Token *Args;
        Token Value;
        Token Body;
        Macro *Next;
        Token (*ExpandFunc) (CPreprocessor *iParent, int iNumArgs, Token *iArgs);
        bool Expanding;

        Macro (const Token &iName) :
            Name (iName), NumArgs (0), Args (NULL), Next (NULL),
            ExpandFunc (NULL), Expanding (false)
        { }

        ~Macro ()
        //{ OGRE_DELETE [] Args; OGRE_DELETE Next; }
        { delete [] Args; delete Next; }

        Token Expand (int iNumArgs, Token *iArgs, Macro *iMacros);
    };

    friend class CPreprocessor::Macro;

    const char *Source;
    const char *SourceEnd;
    int Line;
    bool BOL;
    unsigned EnableOutput;
    Macro *MacroList;

    CPreprocessor (const Token &iToken, int iLine);

    Token GetToken (bool iExpand);

    Token HandleDirective (Token &iToken, int iLine);

    bool HandleDefine (Token &iBody, int iLine);

    bool HandleUnDef (Token &iBody, int iLine);

    bool HandleIfDef (Token &iBody, int iLine);

    bool HandleIf (Token &iBody, int iLine);

    bool HandleElse (Token &iBody, int iLine);

    bool HandleEndIf (Token &iBody, int iLine);

    Token GetArgument (Token &oArg, bool iExpand);

    Token GetArguments (int &oNumArgs, Token *&oArgs, bool iExpand);

    Token GetExpression (Token &oResult, int iLine, int iOpPriority = 0);

    bool GetValue (const Token &iToken, long &oValue, int iLine);

    Token ExpandMacro (const Token &iToken);

    Macro *IsDefined (const Token &iToken);

    static Token ExpandDefined (CPreprocessor *iParent, int iNumArgs, Token *iArgs);

    Token Parse (const Token &iSource);

    void Error (int iLine, const char *iError, const Token *iToken = NULL);

public:
    CPreprocessor () : MacroList (NULL)
    { }

    virtual ~CPreprocessor ();

    void Define (const char *iMacroName, size_t iMacroNameLen,
                 const char *iMacroValue, size_t iMacroValueLen);

    void Define (const char *iMacroName, size_t iMacroNameLen, long iMacroValue);

    bool Undef (const char *iMacroName, size_t iMacroNameLen);

    char *Parse (const char *iSource, size_t iLength, size_t &oLength);

    typedef void (*ErrorHandlerFunc) (
        void *iData, int iLine, const char *iError,
        const char *iToken, size_t iTokenLen);

    static ErrorHandlerFunc ErrorHandler;

    void *ErrorData;
};

} // namespace Ogre

#endif // __OGRE_CPREPROCESSOR_H__