Update year range in copyright notice of binutils files
[deliverable/binutils-gdb.git] / gold / object.cc
index 11c22c6e478ff9eaf29b136bb91b0c8caaf348cf..0c8f7e2598a0aa118d7ee5a13f1f59fb0fed7cd6 100644 (file)
@@ -1,6 +1,6 @@
 // object.cc -- support for an object file for linking in gold
 
-// Copyright (C) 2006-2014 Free Software Foundation, Inc.
+// Copyright (C) 2006-2018 Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
@@ -41,6 +41,7 @@
 #include "plugin.h"
 #include "compressed_output.h"
 #include "incremental.h"
+#include "merge.h"
 
 namespace gold
 {
@@ -268,6 +269,43 @@ Object::handle_split_stack_section(const char* name)
 
 // Class Relobj
 
+template<int size>
+void
+Relobj::initialize_input_to_output_map(unsigned int shndx,
+         typename elfcpp::Elf_types<size>::Elf_Addr starting_address,
+         Unordered_map<section_offset_type,
+         typename elfcpp::Elf_types<size>::Elf_Addr>* output_addresses) const {
+  Object_merge_map *map = this->object_merge_map_;
+  map->initialize_input_to_output_map<size>(shndx, starting_address,
+                                           output_addresses);
+}
+
+void
+Relobj::add_merge_mapping(Output_section_data *output_data,
+                          unsigned int shndx, section_offset_type offset,
+                          section_size_type length,
+                          section_offset_type output_offset) {
+  Object_merge_map* object_merge_map = this->get_or_create_merge_map();
+  object_merge_map->add_mapping(output_data, shndx, offset, length, output_offset);
+}
+
+bool
+Relobj::merge_output_offset(unsigned int shndx, section_offset_type offset,
+                            section_offset_type *poutput) const {
+  Object_merge_map* object_merge_map = this->object_merge_map_;
+  if (object_merge_map == NULL)
+    return false;
+  return object_merge_map->get_output_offset(shndx, offset, poutput);
+}
+
+const Output_section_data*
+Relobj::find_merge_section(unsigned int shndx) const {
+  Object_merge_map* object_merge_map = this->object_merge_map_;
+  if (object_merge_map == NULL)
+    return NULL;
+  return object_merge_map->find_merge_section(shndx);
+}
+
 // To copy the symbols data read from the file to a local data structure.
 // This function is called from do_layout only while doing garbage
 // collection.
@@ -334,7 +372,9 @@ Relobj::is_section_name_included(const char* name)
       || (is_prefix_of(".sdata", name)
          && strstr(name, "personality"))
       || (is_prefix_of(".gnu.linkonce.d", name)
-         && strstr(name, "personality")))
+         && strstr(name, "personality"))
+      || (is_prefix_of(".rodata", name)
+         && strstr(name, "nptl_version")))
     {
       return true;
     }
@@ -366,6 +406,14 @@ Relobj::finalize_incremental_relocs(Layout* layout, bool clear_counts)
   layout->incremental_inputs()->set_reloc_count(rindex);
 }
 
+Object_merge_map*
+Relobj::get_or_create_merge_map()
+{
+  if (!this->object_merge_map_)
+    this->object_merge_map_ = new Object_merge_map();
+  return this->object_merge_map_;
+}
+
 // Class Sized_relobj.
 
 // Iterate over local symbols, calling a visitor class V for each GOT offset
@@ -379,7 +427,8 @@ Sized_relobj<size, big_endian>::do_for_all_local_got_entries(
   unsigned int nsyms = this->local_symbol_count();
   for (unsigned int i = 0; i < nsyms; i++)
     {
-      Local_got_offsets::const_iterator p = this->local_got_offsets_.find(i);
+      Local_got_entry_key key(i, 0);
+      Local_got_offsets::const_iterator p = this->local_got_offsets_.find(key);
       if (p != this->local_got_offsets_.end())
        {
          const Got_offset_list* got_offsets = p->second;
@@ -427,10 +476,10 @@ Sized_relobj_file<size, big_endian>::Sized_relobj_file(
     local_plt_offsets_(),
     kept_comdat_sections_(),
     has_eh_frame_(false),
-    discarded_eh_frame_shndx_(-1U),
+    is_deferred_layout_(false),
     deferred_layout_(),
     deferred_layout_relocs_(),
-    compressed_sections_()
+    output_views_(NULL)
 {
   this->e_type_ = ehdr.get_e_type();
 }
@@ -615,14 +664,12 @@ Sized_relobj_file<size, big_endian>::find_eh_frame(
 
 // Return TRUE if this is a section whose contents will be needed in the
 // Add_symbols task.  This function is only called for sections that have
-// already passed the test in is_compressed_debug_section(), so we know
-// that the section name begins with ".zdebug".
+// already passed the test in is_compressed_debug_section() and the debug
+// section name prefix, ".debug"/".zdebug", has been skipped.
 
 static bool
 need_decompressed_section(const char* name)
 {
-  // Skip over the ".zdebug" and a quick check for the "_".
-  name += 7;
   if (*name++ != '_')
     return false;
 
@@ -672,7 +719,8 @@ build_compressed_section_map(
     unsigned int shnum,
     const char* names,
     section_size_type names_size,
-    Sized_relobj_file<size, big_endian>* obj)
+    Object* obj,
+    bool decompress_if_needed)
 {
   Compressed_section_map* uncompressed_map = new Compressed_section_map();
   const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
@@ -692,24 +740,45 @@ build_compressed_section_map(
            }
 
          const char* name = names + shdr.get_sh_name();
-         if (is_compressed_debug_section(name))
+         bool is_compressed = ((shdr.get_sh_flags()
+                                & elfcpp::SHF_COMPRESSED) != 0);
+         bool is_zcompressed = (!is_compressed
+                                && is_compressed_debug_section(name));
+
+         if (is_zcompressed || is_compressed)
            {
              section_size_type len;
              const unsigned char* contents =
                  obj->section_contents(i, &len, false);
-             uint64_t uncompressed_size = get_uncompressed_size(contents, len);
+             uint64_t uncompressed_size;
+             if (is_zcompressed)
+               {
+                 // Skip over the ".zdebug" prefix.
+                 name += 7;
+                 uncompressed_size = get_uncompressed_size(contents, len);
+               }
+             else
+               {
+                 // Skip over the ".debug" prefix.
+                 name += 6;
+                 elfcpp::Chdr<size, big_endian> chdr(contents);
+                 uncompressed_size = chdr.get_ch_size();
+               }
              Compressed_section_info info;
              info.size = convert_to_section_size_type(uncompressed_size);
+             info.flag = shdr.get_sh_flags();
              info.contents = NULL;
              if (uncompressed_size != -1ULL)
                {
                  unsigned char* uncompressed_data = NULL;
-                 if (need_decompressed_section(name))
+                 if (decompress_if_needed && need_decompressed_section(name))
                    {
                      uncompressed_data = new unsigned char[uncompressed_size];
                      if (decompress_input_section(contents, len,
                                                   uncompressed_data,
-                                                  uncompressed_size))
+                                                  uncompressed_size,
+                                                  size, big_endian,
+                                                  shdr.get_sh_flags()))
                        info.contents = uncompressed_data;
                      else
                        delete[] uncompressed_data;
@@ -737,16 +806,18 @@ Sized_relobj_file<size, big_endian>::do_find_special_sections(
   if (this->find_eh_frame(pshdrs, names, sd->section_names_size))
     this->has_eh_frame_ = true;
 
-  if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL)
-    this->compressed_sections_
-      = build_compressed_section_map(pshdrs, this->shnum(), names,
-                                    sd->section_names_size, this);
+  Compressed_section_map* compressed_sections =
+    build_compressed_section_map<size, big_endian>(
+      pshdrs, this->shnum(), names, sd->section_names_size, this, true);
+  if (compressed_sections != NULL)
+    this->set_compressed_sections(compressed_sections);
+
   return (this->has_eh_frame_
          || (!parameters->options().relocatable()
              && parameters->options().gdb_index()
-             && (memmem(names, sd->section_names_size, "debug_info", 12) == 0
-                 || memmem(names, sd->section_names_size, "debug_types",
-                           13) == 0)));
+             && (memmem(names, sd->section_names_size, "debug_info", 11) != NULL
+                 || memmem(names, sd->section_names_size,
+                           "debug_types", 12) != NULL)));
 }
 
 // Read the sections and symbols from an object file.
@@ -754,6 +825,16 @@ Sized_relobj_file<size, big_endian>::do_find_special_sections(
 template<int size, bool big_endian>
 void
 Sized_relobj_file<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
+{
+  this->base_read_symbols(sd);
+}
+
+// Read the sections and symbols from an object file.  This is common
+// code for all target-specific overrides of do_read_symbols().
+
+template<int size, bool big_endian>
+void
+Sized_relobj_file<size, big_endian>::base_read_symbols(Read_symbols_data* sd)
 {
   this->read_section_data(&this->elf_file_, sd);
 
@@ -1221,13 +1302,7 @@ Sized_relobj_file<size, big_endian>::layout_eh_frame_section(
                                               &offset);
   this->output_sections()[shndx] = os;
   if (os == NULL || offset == -1)
-    {
-      // An object can contain at most one section holding exception
-      // frame information.
-      gold_assert(this->discarded_eh_frame_shndx_ == -1U);
-      this->discarded_eh_frame_shndx_ = shndx;
-      this->section_offsets()[shndx] = invalid_address;
-    }
+    this->section_offsets()[shndx] = invalid_address;
   else
     this->section_offsets()[shndx] = convert_types<Address, off_t>(offset);
 
@@ -1418,6 +1493,7 @@ Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
     {
       parameters->options().plugins()->add_deferred_layout_object(this);
       this->deferred_layout_.reserve(num_sections_to_defer);
+      this->is_deferred_layout_ = true;
     }
 
   // Whether we've seen a .note.GNU-stack section.
@@ -1537,7 +1613,7 @@ Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
              || shdr.get_sh_type() == elfcpp::SHT_INIT_ARRAY
              || shdr.get_sh_type() == elfcpp::SHT_FINI_ARRAY)
            {
-             symtab->gc()->worklist().push(Section_id(this, i));
+             symtab->gc()->worklist().push_back(Section_id(this, i));
            }
          // If the section name XXX can be represented as a C identifier
          // it cannot be discarded if there are references to
@@ -1578,10 +1654,13 @@ Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
        {
          if (is_pass_one)
            {
-             out_sections[i] = reinterpret_cast<Output_section*>(1);
+             if (this->is_deferred_layout())
+               out_sections[i] = reinterpret_cast<Output_section*>(2);
+             else
+               out_sections[i] = reinterpret_cast<Output_section*>(1);
              out_section_offsets[i] = invalid_address;
            }
-         else if (should_defer_layout)
+         else if (this->is_deferred_layout())
            this->deferred_layout_.push_back(Deferred_layout(i, name,
                                                             pshdrs,
                                                             reloc_shndx[i],
@@ -1632,7 +1711,7 @@ Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
                                symtab->icf()->get_folded_section(this, i);
                    Relobj* folded_obj =
                                reinterpret_cast<Relobj*>(folded.first);
-                   gold_info(_("%s: ICF folding section '%s' in file '%s'"
+                   gold_info(_("%s: ICF folding section '%s' in file '%s' "
                                "into '%s' in file '%s'"),
                              program_name, this->section_name(i).c_str(),
                              this->name().c_str(),
@@ -1646,11 +1725,12 @@ Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
        }
 
       // Defer layout here if input files are claimed by plugins.  When gc
-      // is turned on this function is called twice.  For the second call
-      // should_defer_layout should be false.
-      if (should_defer_layout && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
+      // is turned on this function is called twice; we only want to do this
+      // on the first pass.
+      if (!is_pass_two
+          && this->is_deferred_layout()
+          && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC))
        {
-         gold_assert(!is_pass_two);
          this->deferred_layout_.push_back(Deferred_layout(i, name,
                                                           pshdrs,
                                                           reloc_shndx[i],
@@ -1752,6 +1832,8 @@ Sized_relobj_file<size, big_endian>::do_layout(Symbol_table* symtab,
       Output_section* data_section = out_sections[data_shndx];
       if (data_section == reinterpret_cast<Output_section*>(2))
        {
+         if (is_pass_two)
+           continue;
          // The layout for the data section was deferred, so we need
          // to defer the relocation section, too.
          const char* name = pnames + shdr.get_sh_name();
@@ -1848,7 +1930,7 @@ Sized_relobj_file<size, big_endian>::do_layout_deferred_sections(Layout* layout)
 
          // Reading the symbols again here may be slow.
          Read_symbols_data sd;
-         this->read_symbols(&sd);
+         this->base_read_symbols(&sd);
          this->layout_eh_frame_section(layout,
                                        sd.symbols->data(),
                                        sd.symbols_size,
@@ -2103,6 +2185,7 @@ Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
   // Loop over the local symbols.
 
   const Output_sections& out_sections(this->output_sections());
+  std::vector<Address>& out_section_offsets(this->section_offsets());
   unsigned int shnum = this->shnum();
   unsigned int count = 0;
   unsigned int dyncount = 0;
@@ -2111,6 +2194,7 @@ Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
   bool strip_all = parameters->options().strip_all();
   bool discard_all = parameters->options().discard_all();
   bool discard_locals = parameters->options().discard_locals();
+  bool discard_sec_merge = parameters->options().discard_sec_merge();
   for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
     {
       elfcpp::Sym<size, big_endian> sym(psyms);
@@ -2134,9 +2218,14 @@ Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
 
       // Decide whether this symbol should go into the output file.
 
-      if ((shndx < shnum && out_sections[shndx] == NULL)
-         || shndx == this->discarded_eh_frame_shndx_)
+      if (is_ordinary
+         && shndx < shnum
+         && (out_sections[shndx] == NULL
+             || (out_sections[shndx]->order() == ORDER_EHFRAME
+                 && out_section_offsets[shndx] == invalid_address)))
        {
+         // This is either a discarded section or an optimized .eh_frame
+         // section.
          lv.set_no_output_symtab_entry();
          gold_assert(!lv.needs_output_dynsym_entry());
          continue;
@@ -2175,6 +2264,7 @@ Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
          continue;
        }
 
+      // By default, discard temporary local symbols in merge sections.
       // If --discard-locals option is used, discard all temporary local
       // symbols.  These symbols start with system-specific local label
       // prefixes, typically .L for ELF system.  We want to be compatible
@@ -2187,7 +2277,10 @@ Sized_relobj_file<size, big_endian>::do_count_local_symbols(Stringpool* pool,
       //   - the symbol has a name.
       //
       // We do not discard a symbol if it needs a dynamic symbol entry.
-      if (discard_locals
+      if ((discard_locals
+          || (discard_sec_merge
+              && is_ordinary
+              && out_section_offsets[shndx] == invalid_address))
          && sym.get_st_type() != elfcpp::STT_FILE
          && !lv.needs_output_dynsym_entry()
          && lv.may_be_discarded_from_output_symtab()
@@ -2297,10 +2390,10 @@ Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
 
          // This is a SHF_MERGE section or one which otherwise
          // requires special handling.
-         if (shndx == this->discarded_eh_frame_shndx_)
+         if (os->order() == ORDER_EHFRAME)
            {
-             // This local symbol belongs to a discarded .eh_frame
-             // section.  Just treat it like the case in which
+             // This local symbol belongs to a discarded or optimized
+             // .eh_frame section.  Just treat it like the case in which
              // os == NULL above.
              gold_assert(this->has_eh_frame_);
              return This::CFLV_DISCARDED;
@@ -2309,8 +2402,11 @@ Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
            {
              // This is not a section symbol.  We can determine
              // the final value now.
-             lv_out->set_output_value(
-                 os->output_address(this, shndx, lv_in->input_value()));
+             uint64_t value =
+               os->output_address(this, shndx, lv_in->input_value());
+             if (relocatable)
+               value -= os->address();
+             lv_out->set_output_value(value);
            }
          else if (!os->find_starting_output_address(this, shndx, &start))
            {
@@ -2324,10 +2420,10 @@ Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
                os->find_relaxed_input_section(this, shndx);
              if (posd != NULL)
                {
-                 Address relocatable_link_adjustment =
-                   relocatable ? os->address() : 0;
-                 lv_out->set_output_value(posd->address()
-                                          - relocatable_link_adjustment);
+                 uint64_t value = posd->address();
+                 if (relocatable)
+                   value -= os->address();
+                 lv_out->set_output_value(value);
                }
              else
                lv_out->set_output_value(os->address());
@@ -2347,7 +2443,9 @@ Sized_relobj_file<size, big_endian>::compute_final_local_value_internal(
              lv_out->set_merged_symbol_value(msv);
            }
        }
-      else if (lv_in->is_tls_symbol())
+      else if (lv_in->is_tls_symbol()
+               || (lv_in->is_section_symbol()
+                   && (os->flags() & elfcpp::SHF_TLS)))
        lv_out->set_output_value(os->tls_offset()
                                 + secoffset
                                 + lv_in->input_value());
@@ -2567,7 +2665,7 @@ Sized_relobj_file<size, big_endian>::write_local_symbols(
     dyn_oview = of->get_output_view(this->local_dynsym_offset_,
                                    dyn_output_size);
 
-  const Output_sections out_sections(this->output_sections());
+  const Output_sections& out_sections(this->output_sections());
 
   gold_assert(this->local_values_.size() == loccount);
 
@@ -2607,7 +2705,7 @@ Sized_relobj_file<size, big_endian>::write_local_symbols(
          gold_assert(isym.get_st_name() < strtab_size);
          const char* name = pnames + isym.get_st_name();
          osym.put_st_name(sympool->get_offset(name));
-         osym.put_st_value(this->local_values_[i].value(this, 0));
+         osym.put_st_value(lv.value(this, 0));
          osym.put_st_size(isym.get_st_size());
          osym.put_st_info(isym.get_st_info());
          osym.put_st_other(isym.get_st_other());
@@ -2625,7 +2723,7 @@ Sized_relobj_file<size, big_endian>::write_local_symbols(
          gold_assert(isym.get_st_name() < strtab_size);
          const char* name = pnames + isym.get_st_name();
          osym.put_st_name(dynpool->get_offset(name));
-         osym.put_st_value(this->local_values_[i].value(this, 0));
+         osym.put_st_value(lv.value(this, 0));
          osym.put_st_size(isym.get_st_size());
          osym.put_st_info(isym.get_st_info());
          osym.put_st_other(isym.get_st_other());
@@ -2782,9 +2880,8 @@ Sized_relobj_file<size, big_endian>::do_get_global_symbol_counts(
 // to the size.  Set *IS_NEW to true if the contents need to be freed
 // by the caller.
 
-template<int size, bool big_endian>
 const unsigned char*
-Sized_relobj_file<size, big_endian>::do_decompressed_section_contents(
+Object::decompressed_section_contents(
     unsigned int shndx,
     section_size_type* plen,
     bool* is_new)
@@ -2821,7 +2918,10 @@ Sized_relobj_file<size, big_endian>::do_decompressed_section_contents(
   if (!decompress_input_section(buffer,
                                buffer_size,
                                uncompressed_data,
-                               uncompressed_size))
+                               uncompressed_size,
+                               elfsize(),
+                               is_big_endian(),
+                               p->second.flag))
     this->error(_("could not decompress section %s"),
                this->do_section_name(shndx).c_str());
 
@@ -2838,9 +2938,8 @@ Sized_relobj_file<size, big_endian>::do_decompressed_section_contents(
 // Discard any buffers of uncompressed sections.  This is done
 // at the end of the Add_symbols task.
 
-template<int size, bool big_endian>
 void
-Sized_relobj_file<size, big_endian>::do_discard_decompressed_sections()
+Object::discard_decompressed_sections()
 {
   if (this->compressed_sections_ == NULL)
     return;
@@ -2877,11 +2976,20 @@ Input_objects::add_object(Object* obj)
       Dynobj* dynobj = static_cast<Dynobj*>(obj);
       const char* soname = dynobj->soname();
 
-      std::pair<Unordered_set<std::string>::iterator, bool> ins =
-       this->sonames_.insert(soname);
+      Unordered_map<std::string, Object*>::value_type val(soname, obj);
+      std::pair<Unordered_map<std::string, Object*>::iterator, bool> ins =
+       this->sonames_.insert(val);
       if (!ins.second)
        {
          // We have already seen a dynamic object with this soname.
+         // If any instances of this object on the command line have
+         // the --no-as-needed flag, make sure the one we keep is
+         // marked so.
+         if (!obj->as_needed())
+           {
+             gold_assert(ins.first->second != NULL);
+             ins.first->second->clear_as_needed();
+           }
          return false;
        }
 
@@ -3187,6 +3295,24 @@ make_elf_object(const std::string& name, Input_file* input_file, off_t offset,
 
 // Instantiate the templates we need.
 
+#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
+template
+void
+Relobj::initialize_input_to_output_map<64>(unsigned int shndx,
+      elfcpp::Elf_types<64>::Elf_Addr starting_address,
+      Unordered_map<section_offset_type,
+      elfcpp::Elf_types<64>::Elf_Addr>* output_addresses) const;
+#endif
+
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+template
+void
+Relobj::initialize_input_to_output_map<32>(unsigned int shndx,
+      elfcpp::Elf_types<32>::Elf_Addr starting_address,
+      Unordered_map<section_offset_type,
+      elfcpp::Elf_types<32>::Elf_Addr>* output_addresses) const;
+#endif
+
 #ifdef HAVE_TARGET_32_LITTLE
 template
 void
@@ -3327,4 +3453,36 @@ Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
                                     const unsigned char*);
 #endif
 
+#ifdef HAVE_TARGET_32_LITTLE
+template
+Compressed_section_map*
+build_compressed_section_map<32, false>(const unsigned char*, unsigned int,
+                                       const char*, section_size_type, 
+                                       Object*, bool);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+Compressed_section_map*
+build_compressed_section_map<32, true>(const unsigned char*, unsigned int,
+                                       const char*, section_size_type, 
+                                       Object*, bool);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+Compressed_section_map*
+build_compressed_section_map<64, false>(const unsigned char*, unsigned int,
+                                       const char*, section_size_type, 
+                                       Object*, bool);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+Compressed_section_map*
+build_compressed_section_map<64, true>(const unsigned char*, unsigned int,
+                                       const char*, section_size_type, 
+                                       Object*, bool);
+#endif
+
 } // End namespace gold.
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