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/*
 * This tool only runs with the application "intercept-app.cpp".  It's part
 * of a test for PIN_InterceptDebuggingEvent().
 */
 
#include <iostream>
#include <cstdlib>
#include "pin.H"
#include "memlog.hpp"

static void InstrumentRtn(RTN, VOID *);
static VOID InstrumentIns(INS, VOID *);
static void OnCheckpoint(CONTEXT *);
static void OnMemWrite(ADDRINT, ADDRINT);
static BOOL InterceptBreakpoint(THREADID, DEBUGGING_EVENT, CONTEXT *, VOID *);
static void OnExit(INT32, VOID *);

static BOOL FoundCheckpoint = FALSE;
static BOOL IsCheckpointing = FALSE;
static CONTEXT SavedContext;
static MEMLOG MemLog;


int main(int argc, char * argv[])
{
    PIN_Init(argc, argv);
    PIN_InitSymbols();

    RTN_AddInstrumentFunction(InstrumentRtn, 0);
    INS_AddInstrumentFunction(InstrumentIns, 0);
    PIN_InterceptDebuggingEvent(DEBUGGING_EVENT_BREAKPOINT, InterceptBreakpoint, 0);
    PIN_AddFiniFunction(OnExit, 0);
    PIN_StartProgram();
    return 0;
}


// When the application executes the Checkpoint() function, we take a snapshot of the
// registers and start recording changes to memory.  This allows us to roll the application
// back to the Checkpoint() call later.
//
static void InstrumentRtn(RTN rtn, VOID *)
{
    if (RTN_Name(rtn) == "Checkpoint")
    {
        RTN_Open(rtn);
        RTN_InsertCall(rtn, IPOINT_AFTER, AFUNPTR(OnCheckpoint), IARG_CONTEXT, IARG_END);
        FoundCheckpoint = TRUE;
        RTN_Close(rtn);
    }
}

static void InstrumentIns(INS ins, VOID *)
{
    if (INS_IsMemoryWrite(ins))
    {
        INS_InsertCall(ins, IPOINT_BEFORE, (AFUNPTR)OnMemWrite,
            IARG_MEMORYWRITE_EA, IARG_MEMORYWRITE_SIZE, IARG_END);
    }
}

static void OnCheckpoint(CONTEXT *ctxt)
{
    PIN_SaveContext(ctxt, &SavedContext);
    IsCheckpointing = TRUE;
}

static VOID OnMemWrite(ADDRINT addr, ADDRINT size)
{
    if (IsCheckpointing)
        MemLog.Record(addr, size);
}


// This function is called whenever Pin wants to report a breakpoint event to the
// debugger.
//
static BOOL InterceptBreakpoint(THREADID tid, DEBUGGING_EVENT eventType, CONTEXT *ctxt, VOID *)
{
    if (eventType != DEBUGGING_EVENT_BREAKPOINT)
    {
        std::cout << "FAILURE: Wrong event type in InterceptBreakpoint()" << std::endl;
        std::exit(1);
    }

    ADDRINT pc = PIN_GetContextReg(ctxt, REG_INST_PTR);
    RTN rtn = RTN_FindByAddress(pc);
    string rtnName = RTN_Valid(rtn) ? RTN_Name(rtn) : "<N/A>";

    // When the application triggers the breakpoint in Breakpoint1(), squash the breakpoint
    // and roll the application back to the Checkpoint() call.  The application will NOT stop
    // at the breakpoint, and it will immediately resume from Checkpoint().
    //
    if (rtnName == "Breakpoint1")
    {
        std::cout << "Intercepting breakpoint #1 at 0x" << std::hex << pc << std::endl;
        PIN_SaveContext(&SavedContext, ctxt);
        PIN_SetContextReg(ctxt, REG_GAX, 1);
        MemLog.Restore();
        IsCheckpointing = FALSE;
        return FALSE;
    }

    // When the application triggers the breakpoint in Breakpoint2(), do not squash the
    // breakpoint, but change the return value from Breakpoint2().  The application will stop
    // in the debugger, and the debugger should see the modified return value.
    //
    if (rtnName == "Breakpoint2" || rtnName == "Breakpoint2Label")
    {
        std::cout << "Intercepting breakpoint #2 at 0x" << std::hex << pc << std::endl;
        std::cout << "RTN=" << rtnName << std::endl;
        PIN_SetContextReg(ctxt, REG_GAX, 1);
        return TRUE;
    }

    std::cout << "Skipping breakpoint at 0x" << std::hex << pc << ", RTN=" << rtnName << std::endl;
    return TRUE;
}

static void OnExit(INT32, VOID *)
{
    if (!FoundCheckpoint)
    {
        std::cout << "FAILURE: Couldn't add instrumentation routines" << std::endl;
        std::exit(1);
    }
}
