//
//Copyright (C) 2016 Google, Inc.
//
//All rights reserved.
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//    notice, this list of conditions and the following disclaimer.
//
//    Redistributions in binary form must reproduce the above
//    copyright notice, this list of conditions and the following
//    disclaimer in the documentation and/or other materials provided
//    with the distribution.
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//LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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//BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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//
// This holds context specific to the HLSL scanner, which
// sits between the preprocessor scanner and HLSL parser.
//

#ifndef HLSLSCANCONTEXT_H_
#define HLSLSCANCONTEXT_H_

#include "../glslang/MachineIndependent/ParseHelper.h"
#include "hlslTokens.h"

namespace glslang {

class TPpContext;
class TPpToken;


//
// Everything needed to fully describe a token.
//
struct HlslToken {
    HlslToken() : isType(false), string(nullptr), symbol(nullptr) { loc.init(); }
    TSourceLoc loc;                // location of token in the source
    EHlslTokenClass tokenClass;    // what kind of token it is
    bool isType;                   // true if the token represents a user type
    union {                        // what data the token holds
        glslang::TString *string;  // for identifiers
        int i;                     // for literals
        unsigned int u;
        bool b;
        double d;
    };
    glslang::TSymbol* symbol;      // if a symbol table lookup was done already, this is the result
};

//
// The state of scanning and translating raw tokens to slightly richer
// semantics, like knowing if an identifier is an existing symbol, or
// user-defined type.
//
class HlslScanContext {
public:
    HlslScanContext(TParseContextBase& parseContext, TPpContext& ppContext)
        : parseContext(parseContext), ppContext(ppContext), afterType(false), field(false) { }
    virtual ~HlslScanContext() { }

    static void fillInKeywordMap();
    static void deleteKeywordMap();

    void tokenize(HlslToken&);

protected:
    HlslScanContext(HlslScanContext&);
    HlslScanContext& operator=(HlslScanContext&);

    EHlslTokenClass tokenizeClass(HlslToken&);
    EHlslTokenClass tokenizeIdentifier();
    EHlslTokenClass identifierOrType();
    EHlslTokenClass reservedWord();
    EHlslTokenClass identifierOrReserved(bool reserved);
    EHlslTokenClass nonreservedKeyword(int version);

    TParseContextBase& parseContext;
    TPpContext& ppContext;
    bool afterType;           // true if we've recognized a type, so can only be looking for an identifier
    bool field;               // true if we're on a field, right after a '.'
    TSourceLoc loc;
    TPpToken* ppToken;
    HlslToken* parserToken;

    const char* tokenText;
    EHlslTokenClass keyword;
};

} // end namespace glslang

#endif // HLSLSCANCONTEXT_H_