X-Git-Url: https://oss.titaniummirror.com/gitweb?p=msp430-binutils.git;a=blobdiff_plain;f=gold%2Fgc.h;fp=gold%2Fgc.h;h=757a33dc309d590a53cd0d2f26f60e1a3d87f062;hp=0000000000000000000000000000000000000000;hb=d5da4f291af551c0b8b79e1d4a9b173d60e5c10e;hpb=7b5ea4fcdf2819e070665ab5610f8b48e3867c10

diff --git a/gold/gc.h b/gold/gc.h
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+// gc.h -- garbage collection of unused sections
+
+// Copyright 2009 Free Software Foundation, Inc.
+// Written by Sriraman Tallam <tmsriram@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#ifndef GOLD_GC_H
+#define GOLD_GC_H
+
+#include <queue>
+#include <vector>
+
+#include "elfcpp.h"
+#include "symtab.h"
+#include "icf.h"
+
+namespace gold
+{
+
+class Object;
+
+template<int size, bool big_endian>
+class Sized_relobj;
+
+template<int sh_type, int size, bool big_endian>
+class Reloc_types;
+
+class Output_section;
+class General_options;
+class Layout;
+
+typedef std::pair<Object *, unsigned int> Section_id;
+
+class Garbage_collection
+{
+  struct Section_id_hash
+  {
+    size_t operator()(const Section_id& loc) const
+    { return reinterpret_cast<uintptr_t>(loc.first) ^ loc.second; }
+  };
+
+ public:
+
+  typedef Unordered_set<Section_id, Section_id_hash> Sections_reachable;
+  typedef std::map<Section_id, Sections_reachable> Section_ref;
+  typedef std::queue<Section_id> Worklist_type;
+
+  Garbage_collection()
+  : is_worklist_ready_(false)
+  { }
+
+  // Accessor methods for the private members.
+
+  Sections_reachable&
+  referenced_list()
+  { return referenced_list_; }
+
+  Section_ref&
+  section_reloc_map()
+  { return this->section_reloc_map_; }
+
+  Worklist_type&
+  worklist()
+  { return this->work_list_; }
+
+  bool
+  is_worklist_ready()
+  { return this->is_worklist_ready_; }
+
+  void
+  worklist_ready()
+  { this->is_worklist_ready_ = true; }
+
+  void
+  do_transitive_closure();
+
+  bool
+  is_section_garbage(Object* obj, unsigned int shndx)
+  { return (this->referenced_list().find(Section_id(obj, shndx))
+            == this->referenced_list().end()); }
+ private:
+
+  Worklist_type work_list_;
+  bool is_worklist_ready_;
+  Section_ref section_reloc_map_;
+  Sections_reachable referenced_list_;
+};
+
+// Data to pass between successive invocations of do_layout
+// in object.cc while garbage collecting.  This data structure
+// is filled by using the data from Read_symbols_data.
+
+struct Symbols_data
+{
+  // Section headers.
+  unsigned char* section_headers_data;
+  // Section names.
+  unsigned char* section_names_data;
+  // Size of section name data in bytes.
+  section_size_type section_names_size;
+  // Symbol data.
+  unsigned char* symbols_data;
+  // Size of symbol data in bytes.
+  section_size_type symbols_size;
+  // Offset of external symbols within symbol data.  This structure
+  // sometimes contains only external symbols, in which case this will
+  // be zero.  Sometimes it contains all symbols.
+  section_offset_type external_symbols_offset;
+  // Symbol names.
+  unsigned char* symbol_names_data;
+  // Size of symbol name data in bytes.
+  section_size_type symbol_names_size;
+};
+
+// This function implements the generic part of reloc
+// processing to map a section to all the sections it
+// references through relocs.  It is called only during
+// garbage collection (--gc-sections) and identical code
+// folding (--icf).
+
+template<int size, bool big_endian, typename Target_type, int sh_type,
+	 typename Scan>
+inline void
+gc_process_relocs(
+    const General_options& ,
+    Symbol_table* symtab,
+    Layout*,
+    Target_type* ,
+    Sized_relobj<size, big_endian>* src_obj,
+    unsigned int src_indx,
+    const unsigned char* prelocs,
+    size_t reloc_count,
+    Output_section*,
+    bool ,
+    size_t local_count,
+    const unsigned char* plocal_syms)
+{
+  Object *dst_obj;
+  unsigned int dst_indx;
+
+  typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
+  const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
+  const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+
+  std::vector<Section_id>* secvec = NULL;
+  std::vector<Symbol*>* symvec = NULL;
+  std::vector<std::pair<long long, long long> >* addendvec = NULL;
+  bool is_icf_tracked = false;
+
+  if (parameters->options().icf_enabled()
+      && is_prefix_of(".text.", (src_obj)->section_name(src_indx).c_str()))
+    {
+      is_icf_tracked = true;
+      Section_id src_id(src_obj, src_indx);
+      secvec = &symtab->icf()->section_reloc_list()[src_id];
+      symvec = &symtab->icf()->symbol_reloc_list()[src_id];
+      addendvec = &symtab->icf()->addend_reloc_list()[src_id];
+    }
+
+  for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
+    {
+      Reltype reloc(prelocs);
+      typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
+      unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
+      typename elfcpp::Elf_types<size>::Elf_Swxword addend =
+      Reloc_types<sh_type, size, big_endian>::get_reloc_addend_noerror(&reloc);
+
+      if (r_sym < local_count)
+        {
+          gold_assert(plocal_syms != NULL);
+          typename elfcpp::Sym<size, big_endian> lsym(plocal_syms
+                                                      + r_sym * sym_size);
+          unsigned int shndx = lsym.get_st_shndx();
+          bool is_ordinary;
+          shndx = src_obj->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
+          if (!is_ordinary)
+            continue;
+          dst_obj = src_obj;
+          dst_indx = shndx;
+          Section_id dst_id(dst_obj, dst_indx);
+          if (is_icf_tracked)
+            {
+              (*secvec).push_back(dst_id);
+              (*symvec).push_back(NULL);
+              long long symvalue = static_cast<long long>(lsym.get_st_value());
+              (*addendvec).push_back(std::make_pair(symvalue,
+                                              static_cast<long long>(addend)));
+            }
+          if (shndx == src_indx)
+            continue;
+        }
+      else
+        {
+          Symbol* gsym = src_obj->global_symbol(r_sym);
+          gold_assert(gsym != NULL);
+          if (gsym->is_forwarder())
+            gsym = symtab->resolve_forwards(gsym);
+          if (gsym->source() != Symbol::FROM_OBJECT)
+            continue;
+          bool is_ordinary;
+          dst_obj = gsym->object();
+          dst_indx = gsym->shndx(&is_ordinary);
+          if (!is_ordinary)
+            continue;
+          Section_id dst_id(dst_obj, dst_indx);
+          if (is_icf_tracked)
+            {
+              (*secvec).push_back(dst_id);
+              (*symvec).push_back(gsym);
+              Sized_symbol<size>* sized_gsym =
+                        static_cast<Sized_symbol<size>* >(gsym);
+              long long symvalue =
+                        static_cast<long long>(sized_gsym->value());
+              (*addendvec).push_back(std::make_pair(symvalue,
+                                        static_cast<long long>(addend)));
+            }
+        }
+      if (parameters->options().gc_sections())
+        {
+          Section_id src_id(src_obj, src_indx);
+          Section_id dst_id(dst_obj, dst_indx);
+          Garbage_collection::Section_ref::iterator map_it;
+          map_it = symtab->gc()->section_reloc_map().find(src_id);
+          if (map_it == symtab->gc()->section_reloc_map().end())
+            {
+              symtab->gc()->section_reloc_map()[src_id].insert(dst_id);
+            }
+          else
+            {
+              Garbage_collection::Sections_reachable& v(map_it->second);
+              v.insert(dst_id);
+            }
+        }
+    }
+  return;
+}
+
+} // End of namespace gold.
+
+#endif