/*! @file TraceReaderLogQEMU.cc
 *  @brief TraceReaderLogQEMU Implementation
 *
 *  This file contains the implementation of the functions supporting
 *  reading the QEMU coverage data files.
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <string.h>

#include "qemu-log.h"

#include "app_common.h"
#include "TraceReaderBase.h"
#include "TraceReaderLogQEMU.h"
#include "TraceList.h"

/* XXX really not always right */
typedef uint32_t target_ulong;

#include "qemu-traces.h"

/* hack so this can compile on old Linux versions and FreeBSD */
#if (__GNUC__ <= 2) || defined(__FreeBSD__)
#define STAT stat
#define OPEN fopen
#else
#define STAT stat64
#define OPEN fopen64
#endif


namespace Trace {

  TraceReaderLogQEMU::TraceReaderLogQEMU()
  {
  }

  TraceReaderLogQEMU::~TraceReaderLogQEMU()
  {
  }

  bool TraceReaderLogQEMU::processFile(
    const char* const     file
  )
  {
    bool                done          = false;
    QEMU_LOG_IN_Block_t first         = { 0, "", "" };
    QEMU_LOG_IN_Block_t last          = { 0, "", "" };
    QEMU_LOG_IN_Block_t nextExecuted  = { 0, "", "" };
    uint32_t            nextlogical;
    struct STAT         statbuf;
    int                 status;
    FILE*               logFile;
    int                 result;

    //
    // Verify that the log file has a non-zero size.
    //
    // NOTE: We prefer stat64 because some of the coverage files are HUGE!
    status = STAT( file, &statbuf );
    if (status == -1) {
      fprintf( stderr, "Unable to stat %s\n", file );
      return false;
    }

    if (statbuf.st_size == 0) {
      fprintf( stderr, "%s is 0 bytes long\n", file );
      return false;
    }

    //
    // Open the coverage file and discard the header.
    //
    logFile = OPEN( file, "r" );
    if (!logFile) {
      fprintf( stderr, "Unable to open %s\n", file );
      return false;
    }


    //
    //  Discard Header section
    //
    if (! ReadUntilFound( logFile, QEMU_LOG_SECTION_END ) ) {
      fprintf( stderr, "Unable to locate end of log file header\n" );
      return false;
    }

    //
    //  Find first IN block
    //
    if (! ReadUntilFound( logFile, QEMU_LOG_IN_KEY )){
      fprintf(stderr,"Error: Unable to locate first IN: Block in Log file \n");
      return false;
    }

    //
    //  Read First Start Address
    //
    fgets(inputBuffer, MAX_LINE_LENGTH, logFile );
    result = sscanf( 
      inputBuffer, 
      "0x%08lx: %s %s\n", 
      &first.address, 
      first.instruction, 
      first.data 
    );
    if ( result < 2 ) 
    {
      fprintf(stderr, "Error Unable to Read Initial First Block\n" );
      done = true;
    }

    while (!done) {

      last = first;
   
      // Read until we get to the last instruction in the block.
      do {
        fgets(inputBuffer, MAX_LINE_LENGTH, logFile );
        result = sscanf( 
          inputBuffer, 
          "0x%08lx: %s %s\n", 
          &last.address, 
          last.instruction, 
          last.data 
        );
      } while( result > 1);

      nextlogical = objdumpProcessor->getAddressAfter(last.address);

      if (! ReadUntilFound( logFile, QEMU_LOG_IN_KEY )) {
        done = true;
        nextExecuted = last;
      } else {
        fgets(inputBuffer, MAX_LINE_LENGTH, logFile );
        result = sscanf( 
          inputBuffer, 
          "0x%08lx: %s %s\n", 
          &nextExecuted.address, 
          nextExecuted.instruction, 
          nextExecuted.data 
        );
        if ( result < 2 )  
        {
          fprintf(stderr, "Error Unable to Read First Block\n" );
        }
      }

      // If the nextlogical was not found we are throwing away
      // the block; otherwise add the block to the trace list.
      if (nextlogical != 0) {
        TraceList::exitReason_t reason = TraceList::EXIT_REASON_OTHER;

        if ( objdumpProcessor->IsBranch( last.instruction ) ) {
          if ( nextExecuted.address == nextlogical ) {
            reason = TraceList::EXIT_REASON_BRANCH_NOT_TAKEN;
          }  else {
            reason = TraceList::EXIT_REASON_BRANCH_TAKEN;
          }
        }
        Trace.add( first.address, nextlogical, reason );
      }
      first = nextExecuted;
    } 
    fclose( logFile );
    return true;
  }
}