3c_disasm/CInstrFactory.cpp

   1 /*
   2  * Name:     CInstrFactory
   3  * Author:   Martin Perner, 0725782, 535
   4  * E-Mail:   e0725782@student.tuwien.ac.at
   5  * Purpose:  Factory for creating Instruction from shared libraries
   6  * Date:     29.04.2009
   7  */
   8
   9 #include "CInstrFactory.hpp"
  10
  11 using namespace std;
  12
  13 /**
  14  * Name:    loadFromLib
  15  * Purpose: loads a command from the given library file
  16
  17  * Parameter: std::string lib  location of the library file
  18
  19  * Preconditions:  lib references to a valid library
  20  */
  21 Iinstr* CInstrFactory::loadFromLib(string lib)
  22 {
  23         Iinstr* (*create_instruction)();
  24
  25         // load a Instruction from library
  26         void* instruction = dlopen(lib.c_str(), RTLD_LAZY);
  27         if (!instruction) {
  28                 cerr << "Cannot load library: " << dlerror() << endl;
  29                 exit(EXIT_FAILURE);
  30         }
  31
  32         // load the symbols
  33         void* create = dlsym(instruction, "create_instruction");
  34         void* destroy = dlsym(instruction, "destroy_instruction");
  35
  36         if (!create || !destroy) {
  37                 cerr << "Cannot load symbols: " << dlerror() << endl;
  38                 dlclose(instruction);
  39                 exit(EXIT_FAILURE);
  40         }
  41
  42         memcpy(&create_instruction, &create, sizeof(create));
  43
  44         Iinstr* instructionPointer = create_instruction();
  45
  46         m_libStore.insert(make_pair(instruction, instructionPointer));
  47
  48         return instructionPointer;
  49 }
  50
  51 /**
  52  * Name:    getNextInstruction
  53  * Purpose: returns a pointer to a command
  54
  55  * Returns: Pointer to the loaded command
  56
  57  * Throw:  string
  58  * Preconditions:  a command is left to load
  59  */
  60 Iinstr* CInstrFactory::getNextInstr()
  61 {
  62         if(m_files.size() >= 1) {
  63                 Iinstr* instruction;
  64                 instruction = loadFromLib(m_files[0]);
  65                 m_files.erase(m_files.begin());
  66                 return instruction;
  67         }
  68         else {
  69                 throw string("No more instruction left!");
  70         }
  71 }
  72
  73
  74 /**
  75  * Name:    searchLibsInDir
  76  * Purpose: finds librarys in the given directory
  77
  78  * Returns: number of found librarays
  79
  80  * Parameters: std::string dir  Directory where the libraries are located
  81  * Throw:  string
  82  * Postconditions: all files with a trailing '.so' are ready to be used
  83  */
  84 size_t CInstrFactory::searchLibsInDir(string dir)
  85 {
  86         DIR *dp;
  87
  88         if((dp  = opendir(dir.c_str())) == NULL) {
  89                 stringstream errmsg;
  90                 errmsg << "Error(" << errno << ") opening " << dir << endl;
  91                 throw errmsg.str();
  92         }
  93         struct dirent *dirp;
  94         while ((dirp = readdir(dp)) != NULL) {
  95                 string file = dirp->d_name;
  96                 if(file.size() >= 3) {
  97                         file = file.substr(file.size()-3);
  98                         std::transform(file.begin(), file.end(), file.begin(), ::tolower);
  99                         if(file == ".so") {
 100                                 m_files.push_back(dir+"/"+string(dirp->d_name));
 101                         }
 102                 }
 103         }
 104         closedir(dp);
 105         return m_files.size();
 106 }
 107
 108 /**
 109  * Name:    getNumFiles
 110  * Purpose: returns the number of librarys left
 111
 112  * Returns: size_t number of files left
 113  */
 114 size_t CInstrFactory::getNumFiles()
 115 {
 116         return m_files.size();
 117 }
 118
 119 void CInstrFactory::loadLibsIntoMap(map<short, Iinstr*>& instr, string dir)
 120 {
 121 #ifdef DEBUG
 122                 cout << "Loaded " << this->searchLibsInDir(dir) << " Libraryfiles" << endl;
 123 #else
 124                 this->searchLibsInDir(dir);
 125 #endif
 126                 while(this->getNumFiles() >= 1) {
 127                         Iinstr* pinstr = this->getNextInstr();
 128                         instr.insert(make_pair(pinstr->getOpcode(),pinstr));
 129 #ifdef DEBUG
 130                         cout << "found: " << pinstr->getName() << " its opcode is : " << pinstr->getOpcode() << endl;
 131 #endif
 132                 }
 133 }
 134
 135
 136 /**
 137  * Name:    ~CInstrFactory
 138  * Purpose: Destructor of the Object
 139  */
 140 CInstrFactory::~CInstrFactory()
 141 {
 142         void (*destroy_instruction)(Iinstr*);
 143
 144         while(!m_libStore.empty()) {
 145                 void* destroy = dlsym(m_libStore.begin()->first, "destroy_instruction");
 146                 memcpy(&destroy_instruction, &destroy, sizeof(destroy));
 147                 destroy_instruction(m_libStore.begin()->second);
 148                 dlclose(m_libStore.begin()->first);
 149                 m_libStore.erase(m_libStore.begin());
 150         }
 151 }