verilator/include/verilated_vcd_c.h

// -*- mode: C++; c-file-style: "cc-mode" -*-
//=============================================================================
//
// Code available from: https://verilator.org
//
// Copyright 2001-2022 by Wilson Snyder. This program is free software; you
// can redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
//
//=============================================================================
///
/// \file
/// \brief Verilated tracing in VCD format header
///
/// User wrapper code should use this header when creating VCD traces.
///
//=============================================================================

#ifndef VERILATOR_VERILATED_VCD_C_H_
#define VERILATOR_VERILATED_VCD_C_H_

#include "verilated.h"
#include "verilated_trace.h"

#include <map>
#include <string>
#include <vector>

class VerilatedVcd;

//=============================================================================
// VerilatedFile
/// Class representing a file to write to. These virtual methods can be
/// overrode for e.g. socket I/O.

class VerilatedVcdFile VL_NOT_FINAL {
private:
    int m_fd = 0;  // File descriptor we're writing to
public:
    // METHODS
    /// Construct a (as yet) closed file
    VerilatedVcdFile() = default;
    /// Close and destruct
    virtual ~VerilatedVcdFile() = default;
    /// Open a file with given filename
    virtual bool open(const std::string& name) VL_MT_UNSAFE;
    /// Close object's file
    virtual void close() VL_MT_UNSAFE;
    /// Write data to file (if it is open)
    virtual ssize_t write(const char* bufp, ssize_t len) VL_MT_UNSAFE;
};

//=============================================================================
// VerilatedVcd
// Base class to create a Verilator VCD dump
// This is an internally used class - see VerilatedVcdC for what to call from applications

class VerilatedVcd VL_NOT_FINAL : public VerilatedTrace<VerilatedVcd> {
private:
    // Give the superclass access to private bits (to avoid virtual functions)
    friend class VerilatedTrace<VerilatedVcd>;

    //=========================================================================
    // VCD specific internals

    VerilatedVcdFile* m_filep;  // File we're writing to
    bool m_fileNewed;  // m_filep needs destruction
    bool m_isOpen = false;  // True indicates open file
    bool m_evcd = false;  // True for evcd format
    std::string m_filename;  // Filename we're writing to (if open)
    uint64_t m_rolloverMB = 0;  // MB of file size to rollover at
    int m_modDepth = 0;  // Depth of module hierarchy

    char* m_wrBufp;  // Output buffer
    const char* m_wrFlushp;  // Output buffer flush trigger location
    char* m_writep;  // Write pointer into output buffer
    uint64_t m_wrChunkSize;  // Output buffer size
    uint64_t m_wroteBytes = 0;  // Number of bytes written to this file

    std::vector<char> m_suffixes;  // VCD line end string codes + metadata

    using NameMap = std::map<const std::string, const std::string>;
    NameMap* m_namemapp = nullptr;  // List of names for the header

    void bufferResize(uint64_t minsize);
    void bufferFlush() VL_MT_UNSAFE_ONE;
    inline void bufferCheck() {
        // Flush the write buffer if there's not enough space left for new information
        // We only call this once per vector, so we need enough slop for a very wide "b###" line
        if (VL_UNLIKELY(m_writep > m_wrFlushp)) bufferFlush();
    }
    void openNextImp(bool incFilename);
    void closePrev();
    void closeErr();
    void makeNameMap();
    void deleteNameMap();
    void printIndent(int level_change);
    void printStr(const char* str);
    void printQuad(uint64_t n);
    void printTime(uint64_t timeui);
    void declare(uint32_t code, const char* name, const char* wirep, bool array, int arraynum,
                 bool tri, bool bussed, int msb, int lsb);

    void dumpHeader();

    static char* writeCode(char* writep, uint32_t code);

    void finishLine(uint32_t code, char* writep);

    // CONSTRUCTORS
    VL_UNCOPYABLE(VerilatedVcd);

protected:
    //=========================================================================
    // Implementation of VerilatedTrace interface

    // Implementations of protected virtual methods for VerilatedTrace
    virtual void emitTimeChange(uint64_t timeui) override;

    // Hooks called from VerilatedTrace
    virtual bool preFullDump() override { return isOpen(); }
    virtual bool preChangeDump() override;

    // Implementations of duck-typed methods for VerilatedTrace. These are
    // called from only one place (namely full*) so always inline them.
    inline void emitBit(uint32_t code, CData newval);
    inline void emitCData(uint32_t code, CData newval, int bits);
    inline void emitSData(uint32_t code, SData newval, int bits);
    inline void emitIData(uint32_t code, IData newval, int bits);
    inline void emitQData(uint32_t code, QData newval, int bits);
    inline void emitWData(uint32_t code, const WData* newvalp, int bits);
    inline void emitDouble(uint32_t code, double newval);

public:
    //=========================================================================
    // External interface to client code

    explicit VerilatedVcd(VerilatedVcdFile* filep = nullptr);
    ~VerilatedVcd();

    // ACCESSORS
    // Set size in megabytes after which new file should be created
    void rolloverMB(uint64_t rolloverMB) { m_rolloverMB = rolloverMB; }

    // METHODS
    // Open the file; call isOpen() to see if errors
    void open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex);
    // Open next data-only file
    void openNext(bool incFilename) VL_MT_SAFE_EXCLUDES(m_mutex);
    // Close the file
    void close() VL_MT_SAFE_EXCLUDES(m_mutex);
    // Flush any remaining data to this file
    void flush() VL_MT_SAFE_EXCLUDES(m_mutex);
    // Return if file is open
    bool isOpen() const VL_MT_SAFE { return m_isOpen; }

    //=========================================================================
    // Internal interface to Verilator generated code

    void declBit(uint32_t code, const char* name, bool array, int arraynum);
    void declBus(uint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
    void declQuad(uint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
    void declArray(uint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
    void declDouble(uint32_t code, const char* name, bool array, int arraynum);
};

#ifndef DOXYGEN
// Declare specializations here they are used in VerilatedVcdC just below
template <> void VerilatedTrace<VerilatedVcd>::dump(uint64_t timeui);
template <> void VerilatedTrace<VerilatedVcd>::set_time_unit(const char* unitp);
template <> void VerilatedTrace<VerilatedVcd>::set_time_unit(const std::string& unit);
template <> void VerilatedTrace<VerilatedVcd>::set_time_resolution(const char* unitp);
template <> void VerilatedTrace<VerilatedVcd>::set_time_resolution(const std::string& unit);
template <> void VerilatedTrace<VerilatedVcd>::dumpvars(int level, const std::string& hier);
#endif  // DOXYGEN

//=============================================================================
// VerilatedVcdC
/// Class representing a VCD dump file in C standalone (no SystemC)
/// simulations.  Also derived for use in SystemC simulations.

class VerilatedVcdC VL_NOT_FINAL {
    VerilatedVcd m_sptrace;  // Trace file being created

    // CONSTRUCTORS
    VL_UNCOPYABLE(VerilatedVcdC);

public:
    /// Construct the dump. Optional argument is a preconstructed file.
    explicit VerilatedVcdC(VerilatedVcdFile* filep = nullptr)
        : m_sptrace{filep} {}
    /// Destruct, flush, and close the dump
    virtual ~VerilatedVcdC() { close(); }

public:
    // METHODS - User called

    /// Return if file is open
    bool isOpen() const VL_MT_SAFE { return m_sptrace.isOpen(); }
    /// Open a new VCD file
    /// This includes a complete header dump each time it is called,
    /// just as if this object was deleted and reconstructed.
    virtual void open(const char* filename) VL_MT_SAFE { m_sptrace.open(filename); }
    /// Continue a VCD dump by rotating to a new file name
    /// The header is only in the first file created, this allows
    /// "cat" to be used to combine the header plus any number of data files.
    void openNext(bool incFilename = true) VL_MT_SAFE { m_sptrace.openNext(incFilename); }
    /// Set size in megabytes after which new file should be created
    void rolloverMB(size_t rolloverMB) VL_MT_SAFE { m_sptrace.rolloverMB(rolloverMB); }
    /// Close dump
    void close() VL_MT_SAFE { m_sptrace.close(); }
    /// Flush dump
    void flush() VL_MT_SAFE { m_sptrace.flush(); }
    /// Write one cycle of dump data
    /// Call with the current context's time just after eval'ed,
    /// e.g. ->dump(contextp->time())
    void dump(uint64_t timeui) VL_MT_SAFE { m_sptrace.dump(timeui); }
    /// Write one cycle of dump data - backward compatible and to reduce
    /// conversion warnings.  It's better to use a uint64_t time instead.
    void dump(double timestamp) { dump(static_cast<uint64_t>(timestamp)); }
    void dump(uint32_t timestamp) { dump(static_cast<uint64_t>(timestamp)); }
    void dump(int timestamp) { dump(static_cast<uint64_t>(timestamp)); }

    // METHODS - Internal/backward compatible
    // \protectedsection

    // Set time units (s/ms, defaults to ns)
    // Users should not need to call this, as for Verilated models, these
    // propage from the Verilated default timeunit
    void set_time_unit(const char* unit) VL_MT_SAFE { m_sptrace.set_time_unit(unit); }
    void set_time_unit(const std::string& unit) VL_MT_SAFE { m_sptrace.set_time_unit(unit); }
    // Set time resolution (s/ms, defaults to ns)
    // Users should not need to call this, as for Verilated models, these
    // propage from the Verilated default timeprecision
    void set_time_resolution(const char* unit) VL_MT_SAFE { m_sptrace.set_time_resolution(unit); }
    void set_time_resolution(const std::string& unit) VL_MT_SAFE {
        m_sptrace.set_time_resolution(unit);
    }
    // Set variables to dump, using $dumpvars format
    // If level = 0, dump everything and hier is then ignored
    void dumpvars(int level, const std::string& hier) VL_MT_SAFE {
        m_sptrace.dumpvars(level, hier);
    }

    // Internal class access
    inline VerilatedVcd* spTrace() { return &m_sptrace; }
};

#endif  // guard