decompiler.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef STARK_TOOLS_SCRIPT_H
#define STARK_TOOLS_SCRIPT_H

#include "common/str.h"

#include "engines/stark/resources/script.h"

namespace Stark {

namespace Resources {
class Script;
}

namespace Tools {

class Block;
class CFGCommand;
class DefinitionRegistry;
struct ControlStructure;
struct ASTBlock;
struct ASTNode;
struct ASTCondition;
struct ASTLoop;

class Decompiler {
public:
    Decompiler(Resources::Script *script);
    ~Decompiler();

    void printCommands() const;
    void printBlocks() const;
    void printDecompiled();

    Common::String getError() const;

private:
    // Command control flow graph construction
    bool checkCommands();
    void linkCommandBranches();
    CFGCommand *findEntryPoint();

    // Block control flow graph construction
    void buildBlocks();
    void buildBlocks(Block *block, CFGCommand *command);
    Block *buildBranchBlocks(CFGCommand *command);

    // Control flow analysis
    void analyseControlFlow();
    void detectInfiniteLoop();
    void detectWhile();
    void detectIf();

    // AST generation
    ASTNode *buildAST();
    void buildASTFromBlock(ASTBlock *parent, Block *block, Block *stopBlock);
    ASTCondition *buildASTConditionFromBlock(ASTNode *parent, Block *block);
    ASTLoop *buildASTLoopFromBlock(ASTNode *parent, Block *block);

    // AST verification
    void verifyAST();
    bool verifyCommandInAST(CFGCommand *cfgCommand);
    bool verifyCommandSuccessorInAST(CFGCommand *cfgCommand, CFGCommand *cfgSuccessor, ASTNode *astSuccessor, const char *successorType);

    Common::String _error;

    Common::Array<CFGCommand *> _commands;
    CFGCommand *_entryPoint;

    Common::Array<Block *> _blocks;
    Common::Array<ControlStructure *> _controlStructures;

    ASTNode *_astHead;
    Common::Array<Block *> _visitedInfiniteLoopStarts;
    Common::Array<Block *> _visitedBlocks;

    DefinitionRegistry *_definitionRegistry;
};

} // End of namespace Tools
} // End of namespace Stark

#endif // STARK_TOOLS_SCRIPT_H