il_rewriter.h

#ifndef OTEL_CLR_PROFILER_IL_REWRITER_H_
#define OTEL_CLR_PROFILER_IL_REWRITER_H_

// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full
// license information.

#include <corhlpr.h>
#include <corprof.h>

typedef enum
{
#define OPDEF(c, s, pop, push, args, type, l, s1, s2, ctrl) c,
#include "opcode.def"
#undef OPDEF
    CEE_COUNT,
    CEE_SWITCH_ARG,
    // special internal instructions
} OPCODE;

struct ILInstr
{
    ILInstr* m_pNext;
    ILInstr* m_pPrev;

    unsigned m_opcode;
    unsigned m_offset;

    union
    {
        ILInstr* m_pTarget;
        INT8 m_Arg8;
        INT16 m_Arg16;
        INT32 m_Arg32;
        INT64 m_Arg64;
    };
};

struct EHClause
{
    CorExceptionFlag m_Flags;
    ILInstr* m_pTryBegin;
    ILInstr* m_pTryEnd;
    ILInstr* m_pHandlerBegin; // First instruction inside the handler
    ILInstr* m_pHandlerEnd;   // Last instruction inside the handler
    union
    {
        DWORD m_ClassToken; // use for type-based exception handlers
        ILInstr* m_pFilter; // use for filter-based exception handlers
                            // (COR_ILEXCEPTION_CLAUSE_FILTER is set)
    };
};

class ILRewriter
{
private:
    ICorProfilerInfo* m_pICorProfilerInfo;
    ICorProfilerFunctionControl* m_pICorProfilerFunctionControl;

    ModuleID m_moduleId;
    mdToken m_tkMethod;

    mdToken m_tkLocalVarSig;
    unsigned m_maxStack;
    unsigned m_flags;
    bool m_fGenerateTinyHeader;

    ILInstr m_IL; // Double linked list of all il instructions

    unsigned m_nEH;
    EHClause* m_pEH;

    // Helper table for importing.  Sparse array that maps BYTE offset of
    // beginning of an instruction to that instruction's ILInstr*.  BYTE offsets
    // that don't correspond to the beginning of an instruction are mapped to
    // NULL.
    ILInstr** m_pOffsetToInstr;
    unsigned m_CodeSize;

    unsigned m_nInstrs;

    BYTE* m_pOutputBuffer;

    IMethodMalloc* m_pIMethodMalloc;

public:
    ILRewriter(ICorProfilerInfo* pICorProfilerInfo, ICorProfilerFunctionControl* pICorProfilerFunctionControl,
               ModuleID moduleID, mdToken tkMethod);

    ~ILRewriter();

    void InitializeTiny();

    mdToken GetTkLocalVarSig();

    void SetTkLocalVarSig(mdToken tkLocalVarSig);

    unsigned GetEHCount();

    EHClause* GetEHPointer();

    void SetEHClause(EHClause* ehPointer, unsigned ehLength);

    /////////////////////////////////////////////////////////////////////////////////////////////////
    //
    // I M P O R T
    //
    ////////////////////////////////////////////////////////////////////////////////////////////////

    HRESULT Import();

    HRESULT ImportIL(LPCBYTE pIL);

    HRESULT ImportEH(const COR_ILMETHOD_SECT_EH* pILEH, unsigned nEH);

    ILInstr* NewILInstr();

    HRESULT GetInstrFromOffset(unsigned offset, ILInstr** ppInstr);

    void InsertBefore(ILInstr* pWhere, ILInstr* pWhat);

    void InsertAfter(ILInstr* pWhere, ILInstr* pWhat);

    void AdjustState(ILInstr* pNewInstr);

    ILInstr* GetILList();

    /////////////////////////////////////////////////////////////////////////////////////////////////
    //
    // E X P O R T
    //
    ////////////////////////////////////////////////////////////////////////////////////////////////

    HRESULT Export();

    HRESULT SetILFunctionBody(unsigned size, LPBYTE pBody);

    LPBYTE AllocateILMemory(unsigned size);

    void DeallocateILMemory(LPBYTE pBody);

    unsigned GetMaxStackValue();
};

#endif // OTEL_CLR_PROFILER_IL_REWRITER_H_