gold/incremental.h

   1 // inremental.h -- incremental linking support for gold   -*- C++ -*-
   2
   3 // Copyright 2009 Free Software Foundation, Inc.
   4 // Written by Mikolaj Zalewski <mikolajz@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #ifndef GOLD_INCREMENTAL_H
  24 #define GOLD_INCREMENTAL_H
  25
  26 #include <map>
  27 #include <vector>
  28
  29 #include "stringpool.h"
  30 #include "workqueue.h"
  31 #include "fileread.h"
  32
  33 namespace gold
  34 {
  35
  36 class Archive;
  37 class Input_argument;
  38 class Incremental_inputs_checker;
  39 class Object;
  40 class Output_section_data;
  41
  42 // Incremental input type as stored in .gnu_incremental_inputs.
  43
  44 enum Incremental_input_type
  45 {
  46   INCREMENTAL_INPUT_INVALID = 0,
  47   INCREMENTAL_INPUT_OBJECT = 1,
  48   INCREMENTAL_INPUT_ARCHIVE = 2,
  49   INCREMENTAL_INPUT_SHARED_LIBRARY = 3,
  50   INCREMENTAL_INPUT_SCRIPT = 4
  51 };
  52
  53 // This class contains the information needed during an incremental
  54 // build about the inputs necessary to build the .gnu_incremental_inputs.
  55 class Incremental_inputs
  56 {
  57  public:
  58   Incremental_inputs()
  59     : lock_(new Lock()), inputs_(NULL), command_line_key_(0),
  60       strtab_(new Stringpool())
  61   { }
  62   ~Incremental_inputs() { delete this->strtab_; }
  63
  64   // Record the command line.
  65   void
  66   report_command_line(int argc, const char* const* argv);
  67
  68   // Record the input arguments obtained from parsing the command line.
  69   void
  70   report_inputs(const Input_arguments& inputs)
  71   { this->inputs_ = &inputs; }
  72
  73   // Record that the input argument INPUT is an archive ARCHIVE.
  74   void
  75   report_archive(const Input_argument* input, Archive* archive);
  76
  77   // Record that the input argument INPUT is to an object OBJ.
  78   void
  79   report_object(const Input_argument* input, Object* obj);
  80
  81   // Record that the input argument INPUT is to an script SCRIPT.
  82   void
  83   report_script(const Input_argument* input, Timespec mtime,
  84                 Script_info* script);
  85
  86   // Prepare for layout.  Called from Layout::finalize.
  87   void
  88   finalize();
  89
  90   // Create the content of the .gnu_incremental_inputs section.
  91   Output_section_data*
  92   create_incremental_inputs_section_data();
  93
  94   // Return the .gnu_incremental_strtab stringpool.
  95   Stringpool*
  96   get_stringpool()
  97   { return this->strtab_; }
  98
  99  private:
 100   // Code for each of the four possible variants of create_inputs_section_data.
 101   template<int size, bool big_endian>
 102   Output_section_data*
 103   sized_create_inputs_section_data();
 104
 105   // Compute indexes in the order in which the inputs should appear in
 106   // .gnu_incremental_inputs and put file names to the stringtable.
 107   // This needs to be done after all the scripts are parsed.
 108
 109   void
 110   finalize_inputs(Input_argument_list::const_iterator begin,
 111                   Input_argument_list::const_iterator end,
 112                   unsigned int* index);
 113
 114   // Additional data about an input needed for an incremental link.
 115   // None of these pointers is owned by the structure.
 116   struct Input_info
 117   {
 118     Input_info()
 119       : type(INCREMENTAL_INPUT_INVALID), archive(NULL), filename_key(0),
 120         index(0)
 121     { }
 122
 123     // Type of the file pointed by this argument.
 124     Incremental_input_type type;
 125
 126     union
 127     {
 128       // Present if type == INCREMENTAL_INPUT_ARCHIVE.
 129       Archive* archive;
 130
 131       // Present if type == INCREMENTAL_INPUT_OBJECT or
 132       // INCREMENTAL_INPUT_SHARED_LIBRARY.
 133       Object* object;
 134
 135       // Present if type == INCREMENTAL_INPUT_SCRIPT.
 136       Script_info* script;
 137     };
 138
 139     // Key of the filename string in the section stringtable.
 140     Stringpool::Key filename_key;
 141
 142     // Position of the entry information in the output section.
 143     unsigned int index;
 144
 145     // Last modification time of the file.
 146     Timespec mtime;
 147   };
 148
 149   typedef std::map<const Input_argument*, Input_info> Inputs_info_map;
 150
 151   // A lock guarding access to inputs_ during the first phase of linking, when
 152   // report_ function may be called from multiple threads.
 153   Lock* lock_;
 154
 155   // The list of input arguments obtained from parsing the command line.
 156   const Input_arguments* inputs_;
 157
 158   // A map containing additional information about the input elements.
 159   Inputs_info_map inputs_map_;
 160
 161   // The key of the command line string in the string pool.
 162   Stringpool::Key command_line_key_;
 163   // The .gnu_incremental_strtab string pool associated with the
 164   // .gnu_incremental_inputs.
 165   Stringpool* strtab_;
 166 };
 167
 168 } // End namespace gold.
 169
 170 #endif // !defined(GOLD_INCREMENTAL_H)