Add generated files.
[platform/upstream/binutils.git] / gold / symtab.cc
index 8531911..c433018 100644 (file)
@@ -1,6 +1,6 @@
 // symtab.cc -- the gold symbol table
 
-// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright (C) 2006-2014 Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
@@ -40,6 +40,7 @@
 #include "symtab.h"
 #include "script.h"
 #include "plugin.h"
+#include "incremental.h"
 
 namespace gold
 {
@@ -78,6 +79,7 @@ Symbol::init_fields(const char* name, const char* version,
   this->is_defined_in_discarded_section_ = false;
   this->undef_binding_set_ = false;
   this->undef_binding_weak_ = false;
+  this->is_predefined_ = false;
 }
 
 // Return the demangled version of the symbol's name, but only
@@ -132,7 +134,8 @@ void
 Symbol::init_base_output_data(const char* name, const char* version,
                              Output_data* od, elfcpp::STT type,
                              elfcpp::STB binding, elfcpp::STV visibility,
-                             unsigned char nonvis, bool offset_is_from_end)
+                             unsigned char nonvis, bool offset_is_from_end,
+                             bool is_predefined)
 {
   this->init_fields(name, version, type, binding, visibility, nonvis);
   this->u_.in_output_data.output_data = od;
@@ -140,6 +143,7 @@ Symbol::init_base_output_data(const char* name, const char* version,
   this->source_ = IN_OUTPUT_DATA;
   this->in_reg_ = true;
   this->in_real_elf_ = true;
+  this->is_predefined_ = is_predefined;
 }
 
 // Initialize the fields in the base class Symbol for a symbol defined
@@ -150,7 +154,8 @@ Symbol::init_base_output_segment(const char* name, const char* version,
                                 Output_segment* os, elfcpp::STT type,
                                 elfcpp::STB binding, elfcpp::STV visibility,
                                 unsigned char nonvis,
-                                Segment_offset_base offset_base)
+                                Segment_offset_base offset_base,
+                                bool is_predefined)
 {
   this->init_fields(name, version, type, binding, visibility, nonvis);
   this->u_.in_output_segment.output_segment = os;
@@ -158,6 +163,7 @@ Symbol::init_base_output_segment(const char* name, const char* version,
   this->source_ = IN_OUTPUT_SEGMENT;
   this->in_reg_ = true;
   this->in_real_elf_ = true;
+  this->is_predefined_ = is_predefined;
 }
 
 // Initialize the fields in the base class Symbol for a symbol defined
@@ -166,12 +172,14 @@ Symbol::init_base_output_segment(const char* name, const char* version,
 void
 Symbol::init_base_constant(const char* name, const char* version,
                           elfcpp::STT type, elfcpp::STB binding,
-                          elfcpp::STV visibility, unsigned char nonvis)
+                          elfcpp::STV visibility, unsigned char nonvis,
+                          bool is_predefined)
 {
   this->init_fields(name, version, type, binding, visibility, nonvis);
   this->source_ = IS_CONSTANT;
   this->in_reg_ = true;
   this->in_real_elf_ = true;
+  this->is_predefined_ = is_predefined;
 }
 
 // Initialize the fields in the base class Symbol for an undefined
@@ -226,10 +234,11 @@ Sized_symbol<size>::init_output_data(const char* name, const char* version,
                                     elfcpp::STB binding,
                                     elfcpp::STV visibility,
                                     unsigned char nonvis,
-                                    bool offset_is_from_end)
+                                    bool offset_is_from_end,
+                                    bool is_predefined)
 {
   this->init_base_output_data(name, version, od, type, binding, visibility,
-                             nonvis, offset_is_from_end);
+                             nonvis, offset_is_from_end, is_predefined);
   this->value_ = value;
   this->symsize_ = symsize;
 }
@@ -245,10 +254,11 @@ Sized_symbol<size>::init_output_segment(const char* name, const char* version,
                                        elfcpp::STB binding,
                                        elfcpp::STV visibility,
                                        unsigned char nonvis,
-                                       Segment_offset_base offset_base)
+                                       Segment_offset_base offset_base,
+                                       bool is_predefined)
 {
   this->init_base_output_segment(name, version, os, type, binding, visibility,
-                                nonvis, offset_base);
+                                nonvis, offset_base, is_predefined);
   this->value_ = value;
   this->symsize_ = symsize;
 }
@@ -261,9 +271,11 @@ void
 Sized_symbol<size>::init_constant(const char* name, const char* version,
                                  Value_type value, Size_type symsize,
                                  elfcpp::STT type, elfcpp::STB binding,
-                                 elfcpp::STV visibility, unsigned char nonvis)
+                                 elfcpp::STV visibility, unsigned char nonvis,
+                                 bool is_predefined)
 {
-  this->init_base_constant(name, version, type, binding, visibility, nonvis);
+  this->init_base_constant(name, version, type, binding, visibility, nonvis,
+                          is_predefined);
   this->value_ = value;
   this->symsize_ = symsize;
 }
@@ -281,6 +293,21 @@ Sized_symbol<size>::init_undefined(const char* name, const char* version,
   this->symsize_ = 0;
 }
 
+// Return an allocated string holding the symbol's name as
+// name@version.  This is used for relocatable links.
+
+std::string
+Symbol::versioned_name() const
+{
+  gold_assert(this->version_ != NULL);
+  std::string ret = this->name_;
+  ret.push_back('@');
+  if (this->is_def_)
+    ret.push_back('@');
+  ret += this->version_;
+  return ret;
+}
+
 // Return true if SHNDX represents a common symbol.
 
 bool
@@ -307,9 +334,14 @@ Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
 // Return true if this symbol should be added to the dynamic symbol
 // table.
 
-inline bool
+bool
 Symbol::should_add_dynsym_entry(Symbol_table* symtab) const
 {
+  // If the symbol is only present on plugin files, the plugin decided we
+  // don't need it.
+  if (!this->in_real_elf())
+    return false;
+
   // If the symbol is used by a dynamic relocation, we need to add it.
   if (this->needs_dynsym_entry())
     return true;
@@ -331,14 +363,23 @@ Symbol::should_add_dynsym_entry(Symbol_table* symtab) const
         return false;
     }
 
+  // If the symbol was forced dynamic in a --dynamic-list file
+  // or an --export-dynamic-symbol option, add it.
+  if (!this->is_from_dynobj()
+      && (parameters->options().in_dynamic_list(this->name())
+         || parameters->options().is_export_dynamic_symbol(this->name())))
+    {
+      if (!this->is_forced_local())
+        return true;
+      gold_warning(_("Cannot export local symbol '%s'"),
+                  this->demangled_name().c_str());
+      return false;
+    }
+
   // If the symbol was forced local in a version script, do not add it.
   if (this->is_forced_local())
     return false;
 
-  // If the symbol was forced dynamic in a --dynamic-list file, add it.
-  if (parameters->options().in_dynamic_list(this->name()))
-    return true;
-
   // If dynamic-list-data was specified, add any STT_OBJECT.
   if (parameters->options().dynamic_list_data()
       && !this->is_from_dynobj()
@@ -382,6 +423,7 @@ Symbol::should_add_dynsym_entry(Symbol_table* symtab) const
   // externally visible, we need to add it.
   if ((parameters->options().export_dynamic() || parameters->options().shared())
       && !this->is_from_dynobj()
+      && !this->is_undefined()
       && this->is_externally_visible())
     return true;
 
@@ -485,6 +527,30 @@ Symbol::set_output_section(Output_section* os)
     }
 }
 
+// Set the symbol's output segment.  This is used for pre-defined
+// symbols whose segments aren't known until after layout is done
+// (e.g., __ehdr_start).
+
+void
+Symbol::set_output_segment(Output_segment* os, Segment_offset_base base)
+{
+  gold_assert(this->is_predefined_);
+  this->source_ = IN_OUTPUT_SEGMENT;
+  this->u_.in_output_segment.output_segment = os;
+  this->u_.in_output_segment.offset_base = base;
+}
+
+// Set the symbol to undefined.  This is used for pre-defined
+// symbols whose segments aren't known until after layout is done
+// (e.g., __ehdr_start).
+
+void
+Symbol::set_undefined()
+{
+  this->source_ = IS_UNDEFINED;
+  this->is_predefined_ = false;
+}
+
 // Class Symbol_table.
 
 Symbol_table::Symbol_table(unsigned int count,
@@ -518,8 +584,8 @@ Symbol_table::is_section_folded(Object* obj, unsigned int shndx) const
           && this->icf_->is_section_folded(obj, shndx));
 }
 
-// For symbols that have been listed with -u option, add them to the
-// work list to avoid gc'ing them.
+// For symbols that have been listed with a -u or --export-dynamic-symbol
+// option, add them to the work list to avoid gc'ing them.
 
 void 
 Symbol_table::gc_mark_undef_symbols(Layout* layout)
@@ -535,14 +601,24 @@ Symbol_table::gc_mark_undef_symbols(Layout* layout)
       if (sym->source() == Symbol::FROM_OBJECT 
           && !sym->object()->is_dynamic())
         {
-          Relobj* obj = static_cast<Relobj*>(sym->object());
-          bool is_ordinary;
-          unsigned int shndx = sym->shndx(&is_ordinary);
-          if (is_ordinary)
-            {
-              gold_assert(this->gc_ != NULL);
-              this->gc_->worklist().push(Section_id(obj, shndx));
-            }
+         this->gc_mark_symbol(sym);
+        }
+    }
+
+  for (options::String_set::const_iterator p =
+        parameters->options().export_dynamic_symbol_begin();
+       p != parameters->options().export_dynamic_symbol_end();
+       ++p)
+    {
+      const char* name = p->c_str();
+      Symbol* sym = this->lookup(name);
+      // It's not an error if a symbol named by --export-dynamic-symbol
+      // is undefined.
+      if (sym != NULL
+         && sym->source() == Symbol::FROM_OBJECT 
+          && !sym->object()->is_dynamic())
+        {
+         this->gc_mark_symbol(sym);
         }
     }
 
@@ -556,34 +632,23 @@ Symbol_table::gc_mark_undef_symbols(Layout* layout)
       if (sym->source() == Symbol::FROM_OBJECT
          && !sym->object()->is_dynamic())
        {
-         Relobj* obj = static_cast<Relobj*>(sym->object());
-         bool is_ordinary;
-         unsigned int shndx = sym->shndx(&is_ordinary);
-         if (is_ordinary)
-           {
-             gold_assert(this->gc_ != NULL);
-             this->gc_->worklist().push(Section_id(obj, shndx));
-           }
+         this->gc_mark_symbol(sym);
        }
     }
 }
 
 void
-Symbol_table::gc_mark_symbol_for_shlib(Symbol* sym)
+Symbol_table::gc_mark_symbol(Symbol* sym)
 {
-  if (!sym->is_from_dynobj() 
-      && sym->is_externally_visible())
+  // Add the object and section to the work list.
+  bool is_ordinary;
+  unsigned int shndx = sym->shndx(&is_ordinary);
+  if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
     {
-      //Add the object and section to the work list.
-      Relobj* obj = static_cast<Relobj*>(sym->object());
-      bool is_ordinary;
-      unsigned int shndx = sym->shndx(&is_ordinary);
-      if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
-        {
-          gold_assert(this->gc_!= NULL);
-          this->gc_->worklist().push(Section_id(obj, shndx));
-        }
+      gold_assert(this->gc_!= NULL);
+      this->gc_->worklist().push(Section_id(sym->object(), shndx));
     }
+  parameters->target().gc_mark_symbol(this, sym);
 }
 
 // When doing garbage collection, keep symbols that have been seen in
@@ -593,16 +658,7 @@ Symbol_table::gc_mark_dyn_syms(Symbol* sym)
 {
   if (sym->in_dyn() && sym->source() == Symbol::FROM_OBJECT
       && !sym->object()->is_dynamic())
-    {
-      Relobj* obj = static_cast<Relobj*>(sym->object()); 
-      bool is_ordinary;
-      unsigned int shndx = sym->shndx(&is_ordinary);
-      if (is_ordinary && shndx != elfcpp::SHN_UNDEF)
-        {
-          gold_assert(this->gc_ != NULL);
-          this->gc_->worklist().push(Section_id(obj, shndx));
-        }
-    }
+    this->gc_mark_symbol(sym);
 }
 
 // Make TO a symbol which forwards to FROM.
@@ -923,7 +979,8 @@ Symbol_table::add_from_object(Object* object,
       gold_assert(ret != NULL);
 
       was_undefined = ret->is_undefined();
-      was_common = ret->is_common();
+      // Commons from plugins are just placeholders.
+      was_common = ret->is_common() && ret->object()->pluginobj() == NULL;
 
       this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
                    version);
@@ -946,7 +1003,8 @@ Symbol_table::add_from_object(Object* object,
          ret = this->get_sized_symbol<size>(insdefault.first->second);
 
          was_undefined = ret->is_undefined();
-         was_common = ret->is_common();
+         // Commons from plugins are just placeholders.
+         was_common = ret->is_common() && ret->object()->pluginobj() == NULL;
 
          this->resolve(ret, sym, st_shndx, is_ordinary, orig_st_shndx, object,
                        version);
@@ -1009,8 +1067,10 @@ Symbol_table::add_from_object(Object* object,
     }
 
   // Keep track of common symbols, to speed up common symbol
-  // allocation.
-  if (!was_common && ret->is_common())
+  // allocation.  Don't record commons from plugin objects;
+  // we need to wait until we see the real symbol in the
+  // replacement file.
+  if (!was_common && ret->is_common() && ret->object()->pluginobj() == NULL)
     {
       if (ret->type() == elfcpp::STT_TLS)
        this->tls_commons_.push_back(ret);
@@ -1042,13 +1102,13 @@ Symbol_table::add_from_object(Object* object,
 template<int size, bool big_endian>
 void
 Symbol_table::add_from_relobj(
-    Sized_relobj<size, big_endian>* relobj,
+    Sized_relobj_file<size, big_endian>* relobj,
     const unsigned char* syms,
     size_t count,
     size_t symndx_offset,
     const char* sym_names,
     size_t sym_name_size,
-    typename Sized_relobj<size, big_endian>::Symbols* sympointers,
+    typename Sized_relobj_file<size, big_endian>::Symbols* sympointers,
     size_t* defined)
 {
   *defined = 0;
@@ -1076,6 +1136,10 @@ Symbol_table::add_from_relobj(
 
       const char* name = sym_names + st_name;
 
+      if (strcmp (name, "__gnu_lto_slim") == 0)
+        gold_info(_("%s: plugin needed to handle lto object"),
+                 relobj->name().c_str());
+
       bool is_ordinary;
       unsigned int st_shndx = relobj->adjust_sym_shndx(i + symndx_offset,
                                                       sym.get_st_shndx(),
@@ -1110,6 +1174,14 @@ Symbol_table::add_from_relobj(
       bool is_default_version = false;
       bool is_forced_local = false;
 
+      // FIXME: For incremental links, we don't store version information,
+      // so we need to ignore version symbols for now.
+      if (parameters->incremental_update() && ver != NULL)
+       {
+         namelen = ver - name;
+         ver = NULL;
+       }
+
       if (ver != NULL)
         {
           // The symbol name is of the form foo@VERSION or foo@@VERSION
@@ -1159,12 +1231,14 @@ Symbol_table::add_from_relobj(
        {
          memcpy(symbuf, p, sym_size);
          elfcpp::Sym_write<size, big_endian> sw(symbuf);
-         if (orig_st_shndx != elfcpp::SHN_UNDEF && is_ordinary)
+         if (orig_st_shndx != elfcpp::SHN_UNDEF
+             && is_ordinary
+             && relobj->e_type() == elfcpp::ET_REL)
            {
-             // Symbol values in object files are section relative.
-             // This is normally what we want, but since here we are
-             // converting the symbol to absolute we need to add the
-             // section address.  The section address in an object
+             // Symbol values in relocatable object files are section
+             // relative.  This is normally what we want, but since here
+             // we are converting the symbol to absolute we need to add
+             // the section address.  The section address in an object
              // file is normally zero, but people can use a linker
              // script to change it.
              sw.put_st_value(sym.get_st_value()
@@ -1205,15 +1279,21 @@ Symbol_table::add_from_relobj(
                                  is_default_version, *psym, st_shndx,
                                  is_ordinary, orig_st_shndx);
       
-      // If building a shared library using garbage collection, do not 
-      // treat externally visible symbols as garbage.
-      if (parameters->options().gc_sections() 
-          && parameters->options().shared())
-        this->gc_mark_symbol_for_shlib(res);
-
       if (is_forced_local)
        this->force_local(res);
 
+      // Do not treat this symbol as garbage if this symbol will be
+      // exported to the dynamic symbol table.  This is true when
+      // building a shared library or using --export-dynamic and
+      // the symbol is externally visible.
+      if (parameters->options().gc_sections()
+         && res->is_externally_visible()
+         && !res->is_from_dynobj()
+          && (parameters->options().shared()
+             || parameters->options().export_dynamic()
+             || parameters->options().in_dynamic_list(res->name())))
+        this->gc_mark_symbol(res);
+
       if (is_defined_in_discarded_section)
        res->set_is_defined_in_discarded_section();
 
@@ -1298,7 +1378,7 @@ Symbol_table::add_from_dynobj(
     const unsigned char* versym,
     size_t versym_size,
     const std::vector<const char*>* version_map,
-    typename Sized_relobj<size, big_endian>::Symbols* sympointers,
+    typename Sized_relobj_file<size, big_endian>::Symbols* sympointers,
     size_t* defined)
 {
   *defined = 0;
@@ -1311,6 +1391,11 @@ Symbol_table::add_from_dynobj(
       return;
     }
 
+  // FIXME: For incremental links, we don't store version information,
+  // so we need to ignore version symbols for now.
+  if (parameters->incremental_update())
+    versym = NULL;
+
   if (versym != NULL && versym_size / 2 < count)
     {
       dynobj->error(_("too few symbol versions"));
@@ -1480,6 +1565,37 @@ Symbol_table::add_from_dynobj(
   this->record_weak_aliases(&object_symbols);
 }
 
+// Add a symbol from a incremental object file.
+
+template<int size, bool big_endian>
+Sized_symbol<size>*
+Symbol_table::add_from_incrobj(
+    Object* obj,
+    const char* name,
+    const char* ver,
+    elfcpp::Sym<size, big_endian>* sym)
+{
+  unsigned int st_shndx = sym->get_st_shndx();
+  bool is_ordinary = st_shndx < elfcpp::SHN_LORESERVE;
+
+  Stringpool::Key ver_key = 0;
+  bool is_default_version = false;
+  bool is_forced_local = false;
+
+  Stringpool::Key name_key;
+  name = this->namepool_.add(name, true, &name_key);
+
+  Sized_symbol<size>* res;
+  res = this->add_from_object(obj, name, name_key, ver, ver_key,
+                             is_default_version, *sym, st_shndx,
+                             is_ordinary, st_shndx);
+
+  if (is_forced_local)
+    this->force_local(res);
+
+  return res;
+}
+
 // This is used to sort weak aliases.  We sort them first by section
 // index, then by offset, then by weak ahead of strong.
 
@@ -1580,6 +1696,7 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion,
                                    bool* resolve_oldsym)
 {
   *resolve_oldsym = false;
+  *poldsym = NULL;
 
   // If the caller didn't give us a version, see if we get one from
   // the version script.
@@ -1617,7 +1734,9 @@ Symbol_table::define_special_symbol(const char** pname, const char** pversion,
        return NULL;
 
       *pname = oldsym->name();
-      if (!is_default_version)
+      if (is_default_version)
+       *pversion = this->namepool_.add(*pversion, true, NULL);
+      else
        *pversion = oldsym->version();
     }
   else
@@ -1806,7 +1925,8 @@ Symbol_table::do_define_in_output_data(
     return NULL;
 
   sym->init_output_data(name, version, od, value, symsize, type, binding,
-                       visibility, nonvis, offset_is_from_end);
+                       visibility, nonvis, offset_is_from_end,
+                       defined == PREDEFINED);
 
   if (oldsym == NULL)
     {
@@ -1818,7 +1938,7 @@ Symbol_table::do_define_in_output_data(
       return sym;
     }
 
-  if (Symbol_table::should_override_with_special(oldsym, defined))
+  if (Symbol_table::should_override_with_special(oldsym, type, defined))
     this->override_with_special(oldsym, sym);
 
   if (resolve_oldsym)
@@ -1919,7 +2039,8 @@ Symbol_table::do_define_in_output_segment(
     return NULL;
 
   sym->init_output_segment(name, version, os, value, symsize, type, binding,
-                          visibility, nonvis, offset_base);
+                          visibility, nonvis, offset_base,
+                          defined == PREDEFINED);
 
   if (oldsym == NULL)
     {
@@ -1931,7 +2052,7 @@ Symbol_table::do_define_in_output_segment(
       return sym;
     }
 
-  if (Symbol_table::should_override_with_special(oldsym, defined))
+  if (Symbol_table::should_override_with_special(oldsym, type, defined))
     this->override_with_special(oldsym, sym);
 
   if (resolve_oldsym)
@@ -2031,7 +2152,7 @@ Symbol_table::do_define_as_constant(
     return NULL;
 
   sym->init_constant(name, version, value, symsize, type, binding, visibility,
-                    nonvis);
+                    nonvis, defined == PREDEFINED);
 
   if (oldsym == NULL)
     {
@@ -2050,7 +2171,7 @@ Symbol_table::do_define_as_constant(
     }
 
   if (force_override
-      || Symbol_table::should_override_with_special(oldsym, defined))
+      || Symbol_table::should_override_with_special(oldsym, type, defined))
     this->override_with_special(oldsym, sym);
 
   if (resolve_oldsym)
@@ -2216,6 +2337,12 @@ Symbol_table::do_add_undefined_symbols_from_command_line(Layout* layout)
        ++p)
     this->add_undefined_symbol_from_command_line<size>(p->c_str());
 
+  for (options::String_set::const_iterator p =
+        parameters->options().export_dynamic_symbol_begin();
+       p != parameters->options().export_dynamic_symbol_end();
+       ++p)
+    this->add_undefined_symbol_from_command_line<size>(p->c_str());
+
   for (Script_options::referenced_const_iterator p =
         layout->script_options()->referenced_begin();
        p != layout->script_options()->referenced_end();
@@ -2274,6 +2401,27 @@ Symbol_table::set_dynsym_indexes(unsigned int index,
                                 Stringpool* dynpool,
                                 Versions* versions)
 {
+  std::vector<Symbol*> as_needed_sym;
+
+  // Allow a target to set dynsym indexes.
+  if (parameters->target().has_custom_set_dynsym_indexes())
+    {
+      std::vector<Symbol*> dyn_symbols;
+      for (Symbol_table_type::iterator p = this->table_.begin();
+           p != this->table_.end();
+           ++p)
+        {
+          Symbol* sym = p->second;
+          if (!sym->should_add_dynsym_entry(this))
+            sym->set_dynsym_index(-1U);
+          else
+            dyn_symbols.push_back(sym);
+        }
+
+      return parameters->target().set_dynsym_indexes(&dyn_symbols, index, syms,
+                                                     dynpool, versions, this);
+    }
+
   for (Symbol_table_type::iterator p = this->table_.begin();
        p != this->table_.end();
        ++p)
@@ -2293,18 +2441,43 @@ Symbol_table::set_dynsym_indexes(unsigned int index,
          syms->push_back(sym);
          dynpool->add(sym->name(), false, NULL);
 
-         // Record any version information.
-          if (sym->version() != NULL)
-            versions->record_version(this, dynpool, sym);
-
          // If the symbol is defined in a dynamic object and is
-         // referenced in a regular object, then mark the dynamic
-         // object as needed.  This is used to implement --as-needed.
-         if (sym->is_from_dynobj() && sym->in_reg())
+         // referenced strongly in a regular object, then mark the
+         // dynamic object as needed.  This is used to implement
+         // --as-needed.
+         if (sym->is_from_dynobj()
+             && sym->in_reg()
+             && !sym->is_undef_binding_weak())
            sym->object()->set_is_needed();
+
+         // Record any version information, except those from
+         // as-needed libraries not seen to be needed.  Note that the
+         // is_needed state for such libraries can change in this loop.
+         if (sym->version() != NULL)
+           {
+             if (!sym->is_from_dynobj()
+                 || !sym->object()->as_needed()
+                 || sym->object()->is_needed())
+               versions->record_version(this, dynpool, sym);
+             else
+               as_needed_sym.push_back(sym);
+           }
        }
     }
 
+  // Process version information for symbols from as-needed libraries.
+  for (std::vector<Symbol*>::iterator p = as_needed_sym.begin();
+       p != as_needed_sym.end();
+       ++p)
+    {
+      Symbol* sym = *p;
+
+      if (sym->object()->is_needed())
+       versions->record_version(this, dynpool, sym);
+      else
+       sym->clear_version();
+    }
+
   // Finish up the versions.  In some cases this may add new dynamic
   // symbols.
   index = versions->finalize(this, index, syms);
@@ -2366,7 +2539,10 @@ Symbol_table::add_to_final_symtab(Symbol* sym, Stringpool* pool,
                                  unsigned int* pindex, off_t* poff)
 {
   sym->set_symtab_index(*pindex);
-  pool->add(sym->name(), false, NULL);
+  if (sym->version() == NULL || !parameters->options().relocatable())
+    pool->add(sym->name(), false, NULL);
+  else
+    pool->add(sym->versioned_name(), true, NULL);
   ++*pindex;
   *poff += elfcpp::Elf_sizes<size>::sym_size;
 }
@@ -2593,6 +2769,15 @@ Symbol_table::sized_finalize_symbol(Symbol* unsized_sym)
       return false;
     }
 
+  // If the symbol is only present on plugin files, the plugin decided we
+  // don't need it.
+  if (!sym->in_real_elf())
+    {
+      gold_assert(!sym->has_symtab_index());
+      sym->set_symtab_index(-1U);
+      return false;
+    }
+
   // Compute final symbol value.
   Compute_final_value_status status;
   Value_type value = this->compute_final_value(sym, &status);
@@ -2727,6 +2912,12 @@ Symbol_table::sized_write_globals(const Stringpool* sympool,
       typename elfcpp::Elf_types<size>::Elf_Addr sym_value = sym->value();
       typename elfcpp::Elf_types<size>::Elf_Addr dynsym_value = sym_value;
       elfcpp::STB binding = sym->binding();
+
+      // If --no-gnu-unique is set, change STB_GNU_UNIQUE to STB_GLOBAL.
+      if (binding == elfcpp::STB_GNU_UNIQUE
+         && !parameters->options().gnu_unique())
+       binding = elfcpp::STB_GLOBAL;
+
       switch (sym->source())
        {
        case Symbol::FROM_OBJECT:
@@ -2801,15 +2992,24 @@ Symbol_table::sized_write_globals(const Stringpool* sympool,
          break;
 
        case Symbol::IN_OUTPUT_DATA:
-         shndx = sym->output_data()->out_shndx();
-         if (shndx >= elfcpp::SHN_LORESERVE)
-           {
-             if (sym_index != -1U)
-               symtab_xindex->add(sym_index, shndx);
-             if (dynsym_index != -1U)
-               dynsym_xindex->add(dynsym_index, shndx);
-             shndx = elfcpp::SHN_XINDEX;
-           }
+         {
+           Output_data* od = sym->output_data();
+
+           shndx = od->out_shndx();
+           if (shndx >= elfcpp::SHN_LORESERVE)
+             {
+               if (sym_index != -1U)
+                 symtab_xindex->add(sym_index, shndx);
+               if (dynsym_index != -1U)
+                 dynsym_xindex->add(dynsym_index, shndx);
+               shndx = elfcpp::SHN_XINDEX;
+             }
+
+           // In object files symbol values are section
+           // relative.
+           if (parameters->options().relocatable())
+             sym_value -= od->address();
+         }
          break;
 
        case Symbol::IN_OUTPUT_SEGMENT:
@@ -2844,6 +3044,8 @@ Symbol_table::sized_write_globals(const Stringpool* sympool,
          unsigned char* pd = dynamic_view + (dynsym_index * sym_size);
          this->sized_write_symbol<size, big_endian>(sym, dynsym_value, shndx,
                                                     binding, dynpool, pd);
+          // Allow a target to adjust dynamic symbol value.
+          parameters->target().adjust_dyn_symbol(sym, pd);
        }
     }
 
@@ -2866,7 +3068,10 @@ Symbol_table::sized_write_symbol(
     unsigned char* p) const
 {
   elfcpp::Sym_write<size, big_endian> osym(p);
-  osym.put_st_name(pool->get_offset(sym->name()));
+  if (sym->version() == NULL || !parameters->options().relocatable())
+    osym.put_st_name(pool->get_offset(sym->name()));
+  else
+    osym.put_st_name(pool->get_offset(sym->versioned_name()));
   osym.put_st_value(value);
   // Use a symbol size of zero for undefined symbols from shared libraries.
   if (shndx == elfcpp::SHN_UNDEF && sym->is_from_dynobj())
@@ -3011,34 +3216,97 @@ Symbol_table::print_stats() const
 
 // We check for ODR violations by looking for symbols with the same
 // name for which the debugging information reports that they were
-// defined in different source locations.  When comparing the source
-// location, we consider instances with the same base filename and
-// line number to be the same.  This is because different object
-// files/shared libraries can include the same header file using
-// different paths, and we don't want to report an ODR violation in
-// that case.
+// defined in disjoint source locations.  When comparing the source
+// location, we consider instances with the same base filename to be
+// the same.  This is because different object files/shared libraries
+// can include the same header file using different paths, and
+// different optimization settings can make the line number appear to
+// be a couple lines off, and we don't want to report an ODR violation
+// in those cases.
 
 // This struct is used to compare line information, as returned by
 // Dwarf_line_info::one_addr2line.  It implements a < comparison
-// operator used with std::set.
+// operator used with std::sort.
 
 struct Odr_violation_compare
 {
   bool
   operator()(const std::string& s1, const std::string& s2) const
   {
-    std::string::size_type pos1 = s1.rfind('/');
-    std::string::size_type pos2 = s2.rfind('/');
-    if (pos1 == std::string::npos
-       || pos2 == std::string::npos)
-      return s1 < s2;
-    return s1.compare(pos1, std::string::npos,
-                     s2, pos2, std::string::npos) < 0;
+    // Inputs should be of the form "dirname/filename:linenum" where
+    // "dirname/" is optional.  We want to compare just the filename:linenum.
+
+    // Find the last '/' in each string.
+    std::string::size_type s1begin = s1.rfind('/');
+    std::string::size_type s2begin = s2.rfind('/');
+    // If there was no '/' in a string, start at the beginning.
+    if (s1begin == std::string::npos)
+      s1begin = 0;
+    if (s2begin == std::string::npos)
+      s2begin = 0;
+    return s1.compare(s1begin, std::string::npos,
+                     s2, s2begin, std::string::npos) < 0;
   }
 };
 
+// Returns all of the lines attached to LOC, not just the one the
+// instruction actually came from.
+std::vector<std::string>
+Symbol_table::linenos_from_loc(const Task* task,
+                               const Symbol_location& loc)
+{
+  // We need to lock the object in order to read it.  This
+  // means that we have to run in a singleton Task.  If we
+  // want to run this in a general Task for better
+  // performance, we will need one Task for object, plus
+  // appropriate locking to ensure that we don't conflict with
+  // other uses of the object.  Also note, one_addr2line is not
+  // currently thread-safe.
+  Task_lock_obj<Object> tl(task, loc.object);
+
+  std::vector<std::string> result;
+  Symbol_location code_loc = loc;
+  parameters->target().function_location(&code_loc);
+  // 16 is the size of the object-cache that one_addr2line should use.
+  std::string canonical_result = Dwarf_line_info::one_addr2line(
+      code_loc.object, code_loc.shndx, code_loc.offset, 16, &result);
+  if (!canonical_result.empty())
+    result.push_back(canonical_result);
+  return result;
+}
+
+// OutputIterator that records if it was ever assigned to.  This
+// allows it to be used with std::set_intersection() to check for
+// intersection rather than computing the intersection.
+struct Check_intersection
+{
+  Check_intersection()
+    : value_(false)
+  {}
+
+  bool had_intersection() const
+  { return this->value_; }
+
+  Check_intersection& operator++()
+  { return *this; }
+
+  Check_intersection& operator*()
+  { return *this; }
+
+  template<typename T>
+  Check_intersection& operator=(const T&)
+  {
+    this->value_ = true;
+    return *this;
+  }
+
+ private:
+  bool value_;
+};
+
 // Check candidate_odr_violations_ to find symbols with the same name
-// but apparently different definitions (different source-file/line-no).
+// but apparently different definitions (different source-file/line-no
+// for each line assigned to the first instruction).
 
 void
 Symbol_table::detect_odr_violations(const Task* task,
@@ -3048,48 +3316,73 @@ Symbol_table::detect_odr_violations(const Task* task,
        it != candidate_odr_violations_.end();
        ++it)
     {
-      const char* symbol_name = it->first;
-      // Maps from symbol location to a sample object file we found
-      // that location in.  We use a sorted map so the location order
-      // is deterministic, but we only store an arbitrary object file
-      // to avoid copying lots of names.
-      std::map<std::string, std::string, Odr_violation_compare> line_nums;
-
-      for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
-               locs = it->second.begin();
-           locs != it->second.end();
-           ++locs)
+      const char* const symbol_name = it->first;
+
+      std::string first_object_name;
+      std::vector<std::string> first_object_linenos;
+
+      Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
+          locs = it->second.begin();
+      const Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
+          locs_end = it->second.end();
+      for (; locs != locs_end && first_object_linenos.empty(); ++locs)
         {
-         // We need to lock the object in order to read it.  This
-         // means that we have to run in a singleton Task.  If we
-         // want to run this in a general Task for better
-         // performance, we will need one Task for object, plus
-         // appropriate locking to ensure that we don't conflict with
-         // other uses of the object.  Also note, one_addr2line is not
-          // currently thread-safe.
-         Task_lock_obj<Object> tl(task, locs->object);
-          // 16 is the size of the object-cache that one_addr2line should use.
-          std::string lineno = Dwarf_line_info::one_addr2line(
-              locs->object, locs->shndx, locs->offset, 16);
-          if (!lineno.empty())
-            {
-              std::string& sample_object = line_nums[lineno];
-              if (sample_object.empty())
-                sample_object = locs->object->name();
-            }
+          // Save the line numbers from the first definition to
+          // compare to the other definitions.  Ideally, we'd compare
+          // every definition to every other, but we don't want to
+          // take O(N^2) time to do this.  This shortcut may cause
+          // false negatives that appear or disappear depending on the
+          // link order, but it won't cause false positives.
+          first_object_name = locs->object->name();
+          first_object_linenos = this->linenos_from_loc(task, *locs);
         }
 
-      if (line_nums.size() > 1)
+      // Sort by Odr_violation_compare to make std::set_intersection work.
+      std::sort(first_object_linenos.begin(), first_object_linenos.end(),
+                Odr_violation_compare());
+
+      for (; locs != locs_end; ++locs)
         {
-          gold_warning(_("while linking %s: symbol '%s' defined in multiple "
-                         "places (possible ODR violation):"),
-                       output_file_name, demangle(symbol_name).c_str());
-          for (std::map<std::string, std::string>::const_iterator it2 =
-                line_nums.begin();
-              it2 != line_nums.end();
-              ++it2)
-            fprintf(stderr, _("  %s from %s\n"),
-                    it2->first.c_str(), it2->second.c_str());
+          std::vector<std::string> linenos =
+              this->linenos_from_loc(task, *locs);
+          // linenos will be empty if we couldn't parse the debug info.
+          if (linenos.empty())
+            continue;
+          // Sort by Odr_violation_compare to make std::set_intersection work.
+          std::sort(linenos.begin(), linenos.end(), Odr_violation_compare());
+
+          Check_intersection intersection_result =
+              std::set_intersection(first_object_linenos.begin(),
+                                    first_object_linenos.end(),
+                                    linenos.begin(),
+                                    linenos.end(),
+                                    Check_intersection(),
+                                    Odr_violation_compare());
+          if (!intersection_result.had_intersection())
+            {
+              gold_warning(_("while linking %s: symbol '%s' defined in "
+                             "multiple places (possible ODR violation):"),
+                           output_file_name, demangle(symbol_name).c_str());
+              // This only prints one location from each definition,
+              // which may not be the location we expect to intersect
+              // with another definition.  We could print the whole
+              // set of locations, but that seems too verbose.
+              gold_assert(!first_object_linenos.empty());
+              gold_assert(!linenos.empty());
+              fprintf(stderr, _("  %s from %s\n"),
+                      first_object_linenos[0].c_str(),
+                      first_object_name.c_str());
+              fprintf(stderr, _("  %s from %s\n"),
+                      linenos[0].c_str(),
+                      locs->object->name().c_str());
+              // Only print one broken pair, to avoid needing to
+              // compare against a list of the disjoint definition
+              // locations we've found so far.  (If we kept comparing
+              // against just the first one, we'd get a lot of
+              // redundant complaints about the second definition
+              // location.)
+              break;
+            }
         }
     }
   // We only call one_addr2line() in this function, so we can clear its cache.
@@ -3137,6 +3430,12 @@ Warnings::issue_warning(const Symbol* sym,
                        size_t relnum, off_t reloffset) const
 {
   gold_assert(sym->has_warning());
+
+  // We don't want to issue a warning for a relocation against the
+  // symbol in the same object file in which the symbol is defined.
+  if (sym->object() == relinfo->object)
+    return;
+
   Warning_table::const_iterator p = this->warnings_.find(sym->name());
   gold_assert(p != this->warnings_.end());
   gold_warning_at_location(relinfo, relnum, reloffset,
@@ -3163,13 +3462,13 @@ Sized_symbol<64>::allocate_common(Output_data*, Value_type);
 template
 void
 Symbol_table::add_from_relobj<32, false>(
-    Sized_relobj<32, false>* relobj,
+    Sized_relobj_file<32, false>* relobj,
     const unsigned char* syms,
     size_t count,
     size_t symndx_offset,
     const char* sym_names,
     size_t sym_name_size,
-    Sized_relobj<32, false>::Symbols* sympointers,
+    Sized_relobj_file<32, false>::Symbols* sympointers,
     size_t* defined);
 #endif
 
@@ -3177,13 +3476,13 @@ Symbol_table::add_from_relobj<32, false>(
 template
 void
 Symbol_table::add_from_relobj<32, true>(
-    Sized_relobj<32, true>* relobj,
+    Sized_relobj_file<32, true>* relobj,
     const unsigned char* syms,
     size_t count,
     size_t symndx_offset,
     const char* sym_names,
     size_t sym_name_size,
-    Sized_relobj<32, true>::Symbols* sympointers,
+    Sized_relobj_file<32, true>::Symbols* sympointers,
     size_t* defined);
 #endif
 
@@ -3191,13 +3490,13 @@ Symbol_table::add_from_relobj<32, true>(
 template
 void
 Symbol_table::add_from_relobj<64, false>(
-    Sized_relobj<64, false>* relobj,
+    Sized_relobj_file<64, false>* relobj,
     const unsigned char* syms,
     size_t count,
     size_t symndx_offset,
     const char* sym_names,
     size_t sym_name_size,
-    Sized_relobj<64, false>::Symbols* sympointers,
+    Sized_relobj_file<64, false>::Symbols* sympointers,
     size_t* defined);
 #endif
 
@@ -3205,13 +3504,13 @@ Symbol_table::add_from_relobj<64, false>(
 template
 void
 Symbol_table::add_from_relobj<64, true>(
-    Sized_relobj<64, true>* relobj,
+    Sized_relobj_file<64, true>* relobj,
     const unsigned char* syms,
     size_t count,
     size_t symndx_offset,
     const char* sym_names,
     size_t sym_name_size,
-    Sized_relobj<64, true>::Symbols* sympointers,
+    Sized_relobj_file<64, true>::Symbols* sympointers,
     size_t* defined);
 #endif
 
@@ -3267,7 +3566,7 @@ Symbol_table::add_from_dynobj<32, false>(
     const unsigned char* versym,
     size_t versym_size,
     const std::vector<const char*>* version_map,
-    Sized_relobj<32, false>::Symbols* sympointers,
+    Sized_relobj_file<32, false>::Symbols* sympointers,
     size_t* defined);
 #endif
 
@@ -3283,7 +3582,7 @@ Symbol_table::add_from_dynobj<32, true>(
     const unsigned char* versym,
     size_t versym_size,
     const std::vector<const char*>* version_map,
-    Sized_relobj<32, true>::Symbols* sympointers,
+    Sized_relobj_file<32, true>::Symbols* sympointers,
     size_t* defined);
 #endif
 
@@ -3299,7 +3598,7 @@ Symbol_table::add_from_dynobj<64, false>(
     const unsigned char* versym,
     size_t versym_size,
     const std::vector<const char*>* version_map,
-    Sized_relobj<64, false>::Symbols* sympointers,
+    Sized_relobj_file<64, false>::Symbols* sympointers,
     size_t* defined);
 #endif
 
@@ -3315,10 +3614,50 @@ Symbol_table::add_from_dynobj<64, true>(
     const unsigned char* versym,
     size_t versym_size,
     const std::vector<const char*>* version_map,
-    Sized_relobj<64, true>::Symbols* sympointers,
+    Sized_relobj_file<64, true>::Symbols* sympointers,
     size_t* defined);
 #endif
 
+#ifdef HAVE_TARGET_32_LITTLE
+template
+Sized_symbol<32>*
+Symbol_table::add_from_incrobj(
+    Object* obj,
+    const char* name,
+    const char* ver,
+    elfcpp::Sym<32, false>* sym);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+Sized_symbol<32>*
+Symbol_table::add_from_incrobj(
+    Object* obj,
+    const char* name,
+    const char* ver,
+    elfcpp::Sym<32, true>* sym);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+Sized_symbol<64>*
+Symbol_table::add_from_incrobj(
+    Object* obj,
+    const char* name,
+    const char* ver,
+    elfcpp::Sym<64, false>* sym);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+Sized_symbol<64>*
+Symbol_table::add_from_incrobj(
+    Object* obj,
+    const char* name,
+    const char* ver,
+    elfcpp::Sym<64, true>* sym);
+#endif
+
 #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
 template
 void
@@ -3337,6 +3676,32 @@ Symbol_table::define_with_copy_reloc<64>(
     elfcpp::Elf_types<64>::Elf_Addr value);
 #endif
 
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+template
+void
+Sized_symbol<32>::init_output_data(const char* name, const char* version,
+                                  Output_data* od, Value_type value,
+                                  Size_type symsize, elfcpp::STT type,
+                                  elfcpp::STB binding,
+                                  elfcpp::STV visibility,
+                                  unsigned char nonvis,
+                                  bool offset_is_from_end,
+                                  bool is_predefined);
+#endif
+
+#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
+template
+void
+Sized_symbol<64>::init_output_data(const char* name, const char* version,
+                                  Output_data* od, Value_type value,
+                                  Size_type symsize, elfcpp::STT type,
+                                  elfcpp::STB binding,
+                                  elfcpp::STV visibility,
+                                  unsigned char nonvis,
+                                  bool offset_is_from_end,
+                                  bool is_predefined);
+#endif
+
 #ifdef HAVE_TARGET_32_LITTLE
 template
 void