util: Added disassembler using objdump tool.

The disassembler disassembles an elf file with
an external objdump tool.
The architecture specific objdump must be configured
via cmake (ARCH_TOOL_PREFIX), e.g. arm-none-eabi- for
arm-none-eabi-objdump.

src/core/util/Disassembler.cc

@@ -0,0 +1,100 @@
+#include "Disassembler.hpp"
+#include <cstdlib>
+#include "pstream.h"
+#include <sstream>
+#include <iostream>
+#include <vector>
+#include <utility>
+#ifndef __puma
+#include <boost/regex.hpp>
+#include <boost/algorithm/string.hpp>
+#endif
+
+namespace fail {
+
+  const std::string DISASSEMBLER::FAILED = "[Disassembler] Disassemble failed.";
+
+  Disassembler::Disassembler() : m_log("Fail*Disassembler", false){  }
+
+  int Disassembler::init() {
+    // try to open elf file from environment variable
+    char * elfpath = getenv("FAIL_ELF_PATH");
+    if(elfpath == NULL){
+      m_log << "FAIL_ELF_PATH not set :(" << std::endl;
+      return 0;
+    }else{
+      return init(elfpath);
+    }
+  }
+
+  int Disassembler::init(const char* path){
+    // Disassemble ELF
+#ifndef __puma
+    std::string command = std::string(ARCH_TOOL_PREFIX) +  std::string("objdump -d ") + std::string(path);
+    m_log << "Executing: " << command << std::endl;
+    redi::ipstream objdump( command );
+    std::string str;
+    while(std::getline(objdump, str)){
+      evaluate(str);
+    }
+
+    objdump.close();
+    if(objdump.rdbuf()->exited()){
+      int ex = objdump.rdbuf()->status();
+      if(ex != 0){
+        m_code.clear();
+        m_log << "Could not disassemble!" << std::endl;
+        return 0;
+      }
+    }
+    m_log << "disassembled " << m_code.size() << " lines." << std::endl;
+#endif
+    return m_code.size();
+  }
+
+  std::ostream& operator <<(std::ostream & os, const fail::Instruction & i) {
+    os << i.opcode << "\t" << i.instruction << "\t" << i.comment;
+    return os;
+  }
+
+  void Disassembler::evaluate(const std::string& line){
+#ifndef __puma
+    // Only read in real code lines:
+    // Code lines start with a leading whitespace! (hopefully in each objdump implementation!)
+    if(line.size() > 0 && isspace(line[0])){
+      // a line looks like: 800156c:\tdd14          \tble.n   8001598 <_ZN2hw3hal7T32Term8PutBlockEPci+0x30>
+      boost::regex expr("\\s+([A-Fa-f0-9]+):((?:\\s+[A-Fa-f0-9]+)+)\\s+(.+?)(;.*)?$");
+      boost::smatch res;
+      if(boost::regex_search(line, res, expr)){
+        std::string address = res[1];
+        std::stringstream ss;
+        ss << std::hex << address;
+        address_t addr = 0;
+        ss >> addr;
+        std::string opcode = res[2];
+        boost::trim(opcode);
+        std::string instruction = res[3];
+        boost::trim(instruction);
+        std::string comment = res[4];
+        boost::trim(comment);
+
+        m_code.insert(std::make_pair(addr, Instruction(opcode, instruction, comment)));
+      }
+    }
+#endif
+  }
+
+  static Instruction g_InstructionNotFound;
+
+  const Instruction& Disassembler::disassemble(address_t address){
+    InstructionMap_t::const_iterator it = m_code.find(address);
+    if(it == m_code.end()){
+      return g_InstructionNotFound;
+    }else{
+      return it->second;
+    }
+  }
+
+
+} // end of namespace
+