#include "mapped_file.h"

#include <exception/elf.h>
#include <exception/os.h>

#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>

namespace sasm { namespace utils {

mapped_file::~mapped_file()
{
  if (_is_mapped)
    unmap();
}

void mapped_file::map()
{
  int fd;
  struct stat buf;
  char* begin;
  
  if ((fd = open(get_path(), O_RDONLY)) == -1)
    throw sasm::exception::os("open", get_path());

  if (fstat(fd, &buf) == -1)
    throw sasm::exception::os("fstat");

  if (buf.st_size == 0)
    throw sasm::exception::elf(_path.c_str(), "invalid ELF file");

  if ((begin = (char*) mmap(NULL, buf.st_size, PROT_READ, MAP_PRIVATE, fd, 0)) == MAP_FAILED)
    throw sasm::exception::os("mmap");

  close(fd);

  _is_mapped = true;
  _begin = begin;
  _size = buf.st_size;
}

void mapped_file::unmap()
{
  if (munmap((void*) _begin, _size) == -1)
    throw sasm::exception::os("munmap");

  _is_mapped = false;
}

const char* mapped_file::get_path() const
{
  return _path.c_str();
}

}}

#include "mapped_file.h"

#include <exception/os.h>

#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>

namespace sasm { namespace utils {

mapped_file::~mapped_file()
{
  if (_is_mapped)
    unmap();
}

void mapped_file::map()
{
  int fd;
  struct stat buf;
  char* begin;
  
  if ((fd = open(get_path(), O_RDONLY)) == -1)
    throw sasm::exception::os("open", get_path());

  if (fstat(fd, &buf) == -1)
    throw sasm::exception::os("fstat");

  if ((begin = (char*) mmap(NULL, buf.st_size, PROT_READ, MAP_PRIVATE, fd, 0)) == MAP_FAILED)
    throw sasm::exception::os("mmap");

  close(fd);

  _is_mapped = true;
  _begin = begin;
  _size = buf.st_size;
}

void mapped_file::unmap()
{
  if (munmap((void*) _begin, _size) == -1)
    throw sasm::exception::os("munmap");

  _is_mapped = false;
}

const char* mapped_file::get_path() const
{
  return _path.c_str();
}

}}

--- 
+++ 
@@ -1,5 +1,6 @@
 #include "mapped_file.h"
 
+#include <exception/elf.h>
 #include <exception/os.h>
 
 #include <fcntl.h>
@@ -26,6 +27,9 @@
   if (fstat(fd, &buf) == -1)
     throw sasm::exception::os("fstat");
 
+  if (buf.st_size == 0)
+    throw sasm::exception::elf(_path.c_str(), "invalid ELF file");
+
   if ((begin = (char*) mmap(NULL, buf.st_size, PROT_READ, MAP_PRIVATE, fd, 0)) == MAP_FAILED)
     throw sasm::exception::os("mmap");
 
Handle a little bug with empty files.

When giving a length of 0 to mmap(2) we get an EINVAL so the exception
thrown was not accurate.
