gold/readsyms.cc

   1 // readsyms.cc -- read input file symbols for gold
   2
   3 #include "gold.h"
   4
   5 #include <cstring>
   6
   7 #include "elfcpp.h"
   8 #include "options.h"
   9 #include "dirsearch.h"
  10 #include "readsyms.h"
  11
  12 namespace gold
  13 {
  14
  15 // Class read_symbols.
  16
  17 Read_symbols::~Read_symbols()
  18 {
  19   // The this_blocker_ and next_blocker_ pointers are passed on to the
  20   // Add_symbols task.
  21 }
  22
  23 // Return whether a Read_symbols task is runnable.  We need write
  24 // access to the symbol table.  We can read an ordinary input file
  25 // immediately.  For an archive specified using -l, we have to wait
  26 // until the search path is complete.
  27
  28 Task::Is_runnable_type
  29 Read_symbols::is_runnable(Workqueue*)
  30 {
  31   if (this->input_.is_lib() && this->dirpath_.token().is_blocked())
  32     return IS_BLOCKED;
  33
  34   return IS_RUNNABLE;
  35 }
  36
  37 // Return a Task_locker for a Read_symbols task.  We don't need any
  38 // locks here.
  39
  40 Task_locker*
  41 Read_symbols::locks(Workqueue*)
  42 {
  43   return NULL;
  44 }
  45
  46 // Run a Read_symbols task.  This is where we actually read the
  47 // symbols and relocations.
  48
  49 void
  50 Read_symbols::run(Workqueue* workqueue)
  51 {
  52   // We don't keep track of Input_file objects, so this is a memory
  53   // leak.
  54   Input_file* input_file = new Input_file(this->input_);
  55   input_file->open(this->options_, this->dirpath_);
  56
  57   // Read enough of the file to pick up the entire ELF header.
  58
  59   int ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
  60   off_t bytes;
  61   const unsigned char* p = input_file->file().get_view(0, ehdr_size, &bytes);
  62   if (bytes >= 4)
  63     {
  64       static unsigned char elfmagic[4] =
  65         {
  66           elfcpp::ELFMAG0, elfcpp::ELFMAG1,
  67           elfcpp::ELFMAG2, elfcpp::ELFMAG3
  68         };
  69       if (memcmp(p, elfmagic, 4) == 0)
  70         {
  71           // This is an ELF object.
  72           Object* obj = make_elf_object(this->input_.name(), input_file, 0,
  73                                         p, bytes);
  74
  75           Read_symbols_data sd = obj->read_symbols();
  76           workqueue->queue(new Add_symbols(obj, sd, this->this_blocker_,
  77                                            this->next_blocker_));
  78
  79           // Opening the file locked it, so now we need to unlock it.
  80           input_file->file().unlock();
  81
  82           return;
  83         }
  84     }
  85
  86   // Here we have to handle archives and any other input file
  87   // types we need.
  88   gold_fatal("only objects are currently supported", false);
  89 }
  90
  91 // Class Add_symbols.
  92
  93 Add_symbols::~Add_symbols()
  94 {
  95   if (this->this_blocker_ != NULL)
  96     delete this->this_blocker_;
  97   // next_blocker_ is deleted by the task associated with the next
  98   // input file.
  99 }
 100
 101 // We are blocked by this_blocker_.  We block next_blocker_.
 102
 103 Task::Is_runnable_type
 104 Add_symbols::is_runnable(Workqueue*)
 105 {
 106   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 107     return IS_BLOCKED;
 108   return IS_RUNNABLE;
 109 }
 110
 111 Task_locker*
 112 Add_symbols::locks(Workqueue* workqueue)
 113 {
 114   return new Task_locker_block(*this->next_blocker_, workqueue);
 115 }
 116
 117 void
 118 Add_symbols::run(Workqueue*)
 119 {
 120   this->object_->add_symbols(this->sd_);
 121 }
 122
 123 } // End namespace gold.