/*
 * Copyright 2002-2019 Intel Corporation.
 * 
 * This software is provided to you as Sample Source Code as defined in the accompanying
 * End User License Agreement for the Intel(R) Software Development Products ("Agreement")
 * section 1.L.
 * 
 * This software and the related documents are provided as is, with no express or implied
 * warranties, other than those that are expressly stated in the License.
 */

/*
 * Sample buffering tool
 *
 * This tool collects an address trace of instructions that access memory
 * by filling a buffer.  When the buffer overflows,the callback writes all
 * of the collected records to a file.
 *
 * This tool does a similar task as memtrace.cpp, but it uses the buffering api.
 */


#include <iostream>
#include <fstream>
#include <cstdlib>
#include <cstddef>
#include <unistd.h>
#include "pin.H"
using std::hex;
using std::ofstream;
using std::cerr;
using std::string;
using std::endl;



/*
 * Knobs for tool
 */

/*
 * Name of the output file
 */
KNOB<string> KnobOutputFile(KNOB_MODE_WRITEONCE, "pintool", "o", "membuffer.out", "output file");

/*
 * Emit the address trace to the output file
 */
KNOB<BOOL> KnobEmitTrace(KNOB_MODE_WRITEONCE, "pintool", "emit", "0", "emit a trace in the output file");



/* Struct for holding memory references.
 */
struct MEMREF
{
    ADDRINT pc;
    ADDRINT ea;
};

BUFFER_ID bufId;

TLS_KEY mlog_key;

#define NUM_BUF_PAGES 1024


/*
 * MLOG - thread specific data that is not handled by the buffering API.
 */
class MLOG
{
  public:
    MLOG(THREADID tid);
    ~MLOG();

    VOID DumpBufferToFile( struct MEMREF * reference, UINT64 numElements, THREADID tid );


  private:
    ofstream _ofile;
};


MLOG::MLOG(THREADID tid)
{
    if (KnobEmitTrace)
    {
        const string filename = KnobOutputFile.Value() + "." + decstr(getpid()) + "." + decstr(tid);

        _ofile.open(filename.c_str());

        if ( ! _ofile )
        {
            cerr << "Error: could not open output file." << endl;
            exit(1);
        }

        _ofile << hex;
    }
}


MLOG::~MLOG()
{
    if (KnobEmitTrace)
    {
        _ofile.close();
    }
}


VOID MLOG::DumpBufferToFile( struct MEMREF * reference, UINT64 numElements, THREADID tid )
{
    for(UINT64 i=0; i<numElements; i++, reference++)
    {
        if (reference->ea != 0)
            _ofile << reference->pc << "   " << reference->ea << endl;
    }
}


/*!
 *  Print out help message.
 */
INT32 Usage()
{
    cerr << "This tool demonstrates the basic use of the buffering API." << endl << endl;

    return -1;
}


/*
 * Insert code to write data to a thread-specific buffer for instructions
 * that access memory.
 */
VOID Trace(TRACE trace, VOID *v)
{
    // Insert a call to record the effective address.
    for(BBL bbl = TRACE_BblHead(trace); BBL_Valid(bbl); bbl=BBL_Next(bbl))
    {
        for(INS ins = BBL_InsHead(bbl); INS_Valid(ins); ins=INS_Next(ins))
        {
            if(INS_IsMemoryRead(ins) && INS_IsStandardMemop(ins))
            {
                INS_InsertFillBuffer(ins, IPOINT_BEFORE, bufId,
                                     IARG_INST_PTR, offsetof(struct MEMREF, pc),
                                     IARG_MEMORYREAD_EA, offsetof(struct MEMREF, ea),
                                     IARG_END);
            }

            if (INS_HasMemoryRead2(ins) && INS_IsStandardMemop(ins))
            {
                INS_InsertFillBuffer(ins, IPOINT_BEFORE, bufId,
                                     IARG_INST_PTR, offsetof(struct MEMREF, pc),
                                     IARG_MEMORYREAD2_EA, offsetof(struct MEMREF, ea),
                                     IARG_END);
            }

            if(INS_IsMemoryWrite(ins) && INS_IsStandardMemop(ins))
            {
                INS_InsertFillBuffer(ins, IPOINT_BEFORE, bufId,
                                     IARG_INST_PTR, offsetof(struct MEMREF, pc),
                                     IARG_MEMORYWRITE_EA, offsetof(struct MEMREF, ea),
                                     IARG_END);
            }
        }
    }
}


/**************************************************************************
 *
 *  Callback Routines
 *
 **************************************************************************/

/*!
 * Called when a buffer fills up, or the thread exits, so we can process it or pass it off
 * as we see fit.
 * @param[in] id		buffer handle
 * @param[in] tid		id of owning thread
 * @param[in] ctxt		application context
 * @param[in] buf		actual pointer to buffer
 * @param[in] numElements	number of records
 * @param[in] v			callback value
 * @return  A pointer to the buffer to resume filling.
 */
VOID * BufferFull(BUFFER_ID id, THREADID tid, const CONTEXT *ctxt, VOID *buf,
                  UINT64 numElements, VOID *v)
{
    if ( ! KnobEmitTrace )
        return buf;

    struct MEMREF * reference=(struct MEMREF*)buf;

    MLOG * mlog = static_cast<MLOG*>( PIN_GetThreadData( mlog_key, tid ) );

    mlog->DumpBufferToFile( reference, numElements, tid );

    return buf;
}



VOID ThreadStart(THREADID tid, CONTEXT *ctxt, INT32 flags, VOID *v)
{
    // There is a new MLOG for every thread.  Opens the output file.
    MLOG * mlog = new MLOG(tid);

    // A thread will need to look up its MLOG, so save pointer in TLS
    PIN_SetThreadData(mlog_key, mlog, tid);

}


VOID ThreadFini(THREADID tid, const CONTEXT *ctxt, INT32 code, VOID *v)
{
    MLOG * mlog = static_cast<MLOG*>(PIN_GetThreadData(mlog_key, tid));

    delete mlog;

    PIN_SetThreadData(mlog_key, 0, tid);
}


/*!
 * The main procedure of the tool.
 * This function is called when the application image is loaded but not yet started.
 * @param[in]   argc            total number of elements in the argv array
 * @param[in]   argv            array of command line arguments,
 *                              including pin -t <toolname> -- ...
 */
int main(int argc, char *argv[])
{
    // Initialize PIN library. Print help message if -h(elp) is specified
    // in the command line or the command line is invalid
    if( PIN_Init(argc,argv) )
    {
        return Usage();
    }

    // Initialize the memory reference buffer
    bufId = PIN_DefineTraceBuffer(sizeof(struct MEMREF), NUM_BUF_PAGES,
                                  BufferFull, 0);

    if(bufId == BUFFER_ID_INVALID)
    {
        cerr << "Error: could not allocate initial buffer" << endl;
        return 1;
    }

    // Initialize thread-specific data not handled by buffering api.
    mlog_key = PIN_CreateThreadDataKey(0);

    // add an instrumentation function
    TRACE_AddInstrumentFunction(Trace, 0);

    // add callbacks
    PIN_AddThreadStartFunction(ThreadStart, 0);
    PIN_AddThreadFiniFunction(ThreadFini, 0);

    // Start the program, never returns
    PIN_StartProgram();

    return 0;
}