gold/target-select.h

   1 // target-select.h -- select a target for an object file  -*- C++ -*-
   2
   3 #ifndef GOLD_TARGET_SELECT_H
   4 #define GOLD_TARGET_SELECT_H
   5
   6 namespace gold
   7 {
   8
   9 class Target;
  10
  11 // We want to avoid a master list of targets, which implies using a
  12 // global constructor.  And we also want the program to start up as
  13 // quickly as possible, which implies avoiding global constructors.
  14 // We compromise on a very simple global constructor.  We use a target
  15 // selector, which specifies an ELF machine number and a recognition
  16 // function.  We use global constructors to build a linked list of
  17 // target selectors--a simple pointer list, not a std::list.
  18
  19 class Target_selector
  20 {
  21  public:
  22   // Create a target selector for a specific machine number, size (32
  23   // or 64), and endianness.  The machine number can be EM_NONE to
  24   // test for any machine number.
  25   Target_selector(int machine, int size, bool big_endian);
  26
  27   virtual ~Target_selector()
  28   { }
  29
  30   // If we can handle this target, return a pointer to a target
  31   // structure.  The size and endianness are known.
  32   virtual Target* recognize(int machine, int osabi, int abiversion) const = 0;
  33
  34   // Return the next Target_selector in the linked list.
  35   Target_selector*
  36   next() const
  37   { return this->next_; }
  38
  39   // Return the machine number this selector is looking for, which can
  40   // be EM_NONE to match any machine number.
  41   int
  42   machine() const
  43   { return this->machine_; }
  44
  45   // Return the size this is looking for (32 or 64).
  46   int
  47   size() const
  48   { return this->size_; }
  49
  50   // Return the endianness this is looking for.
  51   bool
  52   big_endian() const
  53   { return this->big_endian_; }
  54
  55  private:
  56   int machine_;
  57   int size_;
  58   bool big_endian_;
  59   Target_selector* next_;
  60 };
  61
  62 // Select the target for an ELF file.
  63
  64 extern Target* select_target(int machine, int size, bool big_endian,
  65                              int osabi, int abiversion);
  66
  67 } // End namespace gold.
  68
  69 #endif // !defined(GOLD_TARGET_SELECT_H)