Add -Wshadow to the gcc command line options used when compiling the binutils.
[deliverable/binutils-gdb.git] / gold / merge.cc
index 15d3b7cd1bd9e510d2390963019881bc5627b4e8..654f3495fee34a3ee727e1a0ad518706b5197797 100644 (file)
@@ -1,6 +1,6 @@
 // merge.cc -- handle section merging for gold
 
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
 namespace gold
 {
 
-// Class Merge_map::Merge_key_less.
+// Class Object_merge_map.
 
-// Sort the entries in a merge mapping.  The key is an input object, a
-// section index in that object, and an offset in that section.
+// Destructor.
+
+Object_merge_map::~Object_merge_map()
+{
+  for (Section_merge_maps::iterator p = this->section_merge_maps_.begin();
+       p != this->section_merge_maps_.end();
+       ++p)
+    delete p->second;
+}
+
+// Get the Input_merge_map to use for an input section, or NULL.
+
+Object_merge_map::Input_merge_map*
+Object_merge_map::get_input_merge_map(unsigned int shndx)
+{
+  gold_assert(shndx != -1U);
+  if (shndx == this->first_shnum_)
+    return &this->first_map_;
+  if (shndx == this->second_shnum_)
+    return &this->second_map_;
+  Section_merge_maps::const_iterator p = this->section_merge_maps_.find(shndx);
+  if (p != this->section_merge_maps_.end())
+    return p->second;
+  return NULL;
+}
+
+// Get or create the Input_merge_map to use for an input section.
+
+Object_merge_map::Input_merge_map*
+Object_merge_map::get_or_make_input_merge_map(const Merge_map* merge_map,
+                                             unsigned int shndx)
+{
+  Input_merge_map* map = this->get_input_merge_map(shndx);
+  if (map != NULL)
+    {
+      // For a given input section in a given object, every mapping
+      // must be done with the same Merge_map.
+      gold_assert(map->merge_map == merge_map);
+      return map;
+    }
+
+  // We need to create a new entry.
+  if (this->first_shnum_ == -1U)
+    {
+      this->first_shnum_ = shndx;
+      this->first_map_.merge_map = merge_map;
+      return &this->first_map_;
+    }
+  if (this->second_shnum_ == -1U)
+    {
+      this->second_shnum_ = shndx;
+      this->second_map_.merge_map = merge_map;
+      return &this->second_map_;
+    }
+
+  Input_merge_map* new_map = new Input_merge_map;
+  new_map->merge_map = merge_map;
+  this->section_merge_maps_[shndx] = new_map;
+  return new_map;
+}
+
+// Add a mapping.
+
+void
+Object_merge_map::add_mapping(const Merge_map* merge_map, unsigned int shndx,
+                             section_offset_type input_offset,
+                             section_size_type length,
+                             section_offset_type output_offset)
+{
+  Input_merge_map* map = this->get_or_make_input_merge_map(merge_map, shndx);
+
+  // Try to merge the new entry in the last one we saw.
+  if (!map->entries.empty())
+    {
+      Input_merge_entry& entry(map->entries.back());
+
+      // Use section_size_type to avoid signed/unsigned warnings.
+      section_size_type input_offset_u = input_offset;
+      section_size_type output_offset_u = output_offset;
+
+      // If this entry is not in order, we need to sort the vector
+      // before looking anything up.
+      if (input_offset_u < entry.input_offset + entry.length)
+       {
+         gold_assert(input_offset < entry.input_offset);
+         gold_assert(input_offset_u + length
+                     <= static_cast<section_size_type>(entry.input_offset));
+         map->sorted = false;
+       }
+      else if (entry.input_offset + entry.length == input_offset_u
+              && (output_offset == -1
+                  ? entry.output_offset == -1
+                  : entry.output_offset + entry.length == output_offset_u))
+       {
+         entry.length += length;
+         return;
+       }
+    }
+
+  Input_merge_entry entry;
+  entry.input_offset = input_offset;
+  entry.length = length;
+  entry.output_offset = output_offset;
+  map->entries.push_back(entry);
+}
+
+// Get the output offset for an input address.
 
 bool
-Merge_map::Merge_key_less::operator()(const Merge_key& mk1,
-                                     const Merge_key& mk2) const
+Object_merge_map::get_output_offset(const Merge_map* merge_map,
+                                   unsigned int shndx,
+                                   section_offset_type input_offset,
+                                   section_offset_type *output_offset)
 {
-  // The order of different objects and different sections doesn't
-  // matter.  We want to get consistent results across links so we
-  // don't use pointer comparison.
-  if (mk1.object != mk2.object)
+  Input_merge_map* map = this->get_input_merge_map(shndx);
+  if (map == NULL
+      || (merge_map != NULL && map->merge_map != merge_map))
+    return false;
+
+  if (!map->sorted)
     {
-      // Two different object files can have the same name: if foo.a
-      // includes both bar/qux.o and baz/qux.o, then both end up with
-      // the name foo.a(qux.o).  But it's impossible for two different
-      // object files to have both the same name and the same offset.
-      if (mk1.object->offset() != mk2.object->offset())
-        return mk1.object->offset() < mk2.object->offset();
-      return mk1.object->name() < mk2.object->name();
+      std::sort(map->entries.begin(), map->entries.end(),
+               Input_merge_compare());
+      map->sorted = true;
+    }
+
+  Input_merge_entry entry;
+  entry.input_offset = input_offset;
+  std::vector<Input_merge_entry>::const_iterator p =
+    std::lower_bound(map->entries.begin(), map->entries.end(),
+                    entry, Input_merge_compare());
+  if (p == map->entries.end() || p->input_offset > input_offset)
+    {
+      if (p == map->entries.begin())
+       return false;
+      --p;
+      gold_assert(p->input_offset <= input_offset);
+    }
+
+  if (input_offset - p->input_offset
+      >= static_cast<section_offset_type>(p->length))
+    return false;
+
+  *output_offset = p->output_offset;
+  if (*output_offset != -1)
+    *output_offset += (input_offset - p->input_offset);
+  return true;
+}
+
+// Return whether this is the merge map for section SHNDX.
+
+inline bool
+Object_merge_map::is_merge_section_for(const Merge_map* merge_map,
+                                      unsigned int shndx)
+{
+  Input_merge_map* map = this->get_input_merge_map(shndx);
+  return map != NULL && map->merge_map == merge_map;
+}
+
+// Initialize a mapping from input offsets to output addresses.
+
+template<int size>
+void
+Object_merge_map::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>* initialize_map)
+{
+  Input_merge_map* map = this->get_input_merge_map(shndx);
+  gold_assert(map != NULL);
+
+  gold_assert(initialize_map->empty());
+  // We know how many entries we are going to add.
+  // reserve_unordered_map takes an expected count of buckets, not a
+  // count of elements, so double it to try to reduce collisions.
+  reserve_unordered_map(initialize_map, map->entries.size() * 2);
+
+  for (Input_merge_map::Entries::const_iterator p = map->entries.begin();
+       p != map->entries.end();
+       ++p)
+    {
+      section_offset_type output_offset = p->output_offset;
+      if (output_offset != -1)
+       output_offset += starting_address;
+      else
+       {
+         // If we see a relocation against an address we have chosen
+         // to discard, we relocate to zero.  FIXME: We could also
+         // issue a warning in this case; that would require
+         // reporting this somehow and checking it in the routines in
+         // reloc.h.
+         output_offset = 0;
+       }
+      initialize_map->insert(std::make_pair(p->input_offset, output_offset));
     }
-  if (mk1.shndx != mk2.shndx)
-    return mk1.shndx < mk2.shndx;
-  return mk1.offset < mk2.offset;
 }
 
 // Class Merge_map.
 
 // Add a mapping for the bytes from OFFSET to OFFSET + LENGTH in input
-// section SHNDX in object OBJECT to an OUTPUT_OFFSET in a merged
-// output section.
+// section SHNDX in object OBJECT to an OUTPUT_OFFSET in merged data
+// in an output section.
 
 void
 Merge_map::add_mapping(Relobj* object, unsigned int shndx,
-                      off_t offset, off_t length, off_t output_offset)
+                      section_offset_type offset, section_size_type length,
+                      section_offset_type output_offset)
 {
-  Merge_key mk;
-  mk.object = object;
-  mk.shndx = shndx;
-  mk.offset = offset;
-
-  Merge_value mv;
-  mv.length = length;
-  mv.output_offset = output_offset;
-
-  std::pair<Merge_mapping::iterator, bool> ins =
-    this->merge_map_.insert(std::make_pair(mk, mv));
-  gold_assert(ins.second);
+  Object_merge_map* object_merge_map = object->merge_map();
+  if (object_merge_map == NULL)
+    {
+      object_merge_map = new Object_merge_map();
+      object->set_merge_map(object_merge_map);
+    }
+
+  object_merge_map->add_mapping(this, shndx, offset, length, output_offset);
 }
 
 // Return the output offset for an input address.  The input address
 // is at offset OFFSET in section SHNDX in OBJECT.  This sets
-// *OUTPUT_OFFSET to the offset in the output section.  This returns
-// true if the mapping is known, false otherwise.
+// *OUTPUT_OFFSET to the offset in the merged data in the output
+// section.  This returns true if the mapping is known, false
+// otherwise.
 
 bool
 Merge_map::get_output_offset(const Relobj* object, unsigned int shndx,
-                            off_t offset, off_t* output_offset) const
+                            section_offset_type offset,
+                            section_offset_type* output_offset) const
 {
-  Merge_key mk;
-  mk.object = object;
-  mk.shndx = shndx;
-  mk.offset = offset;
-  Merge_mapping::const_iterator p = this->merge_map_.lower_bound(mk);
-
-  // If MK is not in the map, lower_bound returns the next iterator
-  // larger than it.
-  if (p == this->merge_map_.end()
-      || p->first.object != object
-      || p->first.shndx != shndx
-      || p->first.offset != offset)
-    {
-      if (p == this->merge_map_.begin())
-       return false;
-      --p;
-    }
-
-  if (p->first.object != object || p->first.shndx != shndx)
+  Object_merge_map* object_merge_map = object->merge_map();
+  if (object_merge_map == NULL)
     return false;
+  return object_merge_map->get_output_offset(this, shndx, offset,
+                                            output_offset);
+}
 
-  if (offset - p->first.offset >= p->second.length)
-    return false;
+// Return whether this is the merge section for SHNDX in OBJECT.
 
-  *output_offset = p->second.output_offset;
-  if (*output_offset != -1)
-    *output_offset += (offset - p->first.offset);
-  return true;
+bool
+Merge_map::is_merge_section_for(const Relobj* object, unsigned int shndx) const
+{
+  Object_merge_map* object_merge_map = object->merge_map();
+  if (object_merge_map == NULL)
+    return false;
+  return object_merge_map->is_merge_section_for(this, shndx);
 }
 
 // Class Output_merge_base.
@@ -129,10 +289,19 @@ Merge_map::get_output_offset(const Relobj* object, unsigned int shndx,
 bool
 Output_merge_base::do_output_offset(const Relobj* object,
                                    unsigned int shndx,
-                                   off_t offset,
-                                   off_t* poutput) const
+                                   section_offset_type off,
+                                   section_offset_type* poutput) const
 {
-  return this->merge_map_.get_output_offset(object, shndx, offset, poutput);
+  return this->merge_map_.get_output_offset(object, shndx, off, poutput);
+}
+
+// Return whether this is the merge section for SHNDX in OBJECT.
+
+bool
+Output_merge_base::do_is_merge_section_for(const Relobj* object,
+                                          unsigned int shndx) const
+{
+  return this->merge_map_.is_merge_section_for(object, shndx);
 }
 
 // Class Output_merge_data.
@@ -143,13 +312,14 @@ size_t
 Output_merge_data::Merge_data_hash::operator()(Merge_data_key k) const
 {
   const unsigned char* p = this->pomd_->constant(k);
-  uint64_t entsize = this->pomd_->entsize();
+  section_size_type entsize =
+    convert_to_section_size_type(this->pomd_->entsize());
 
   // Fowler/Noll/Vo (FNV) hash (type FNV-1a).
   if (sizeof(size_t) == 8)
     {
       size_t result = static_cast<size_t>(14695981039346656037ULL);
-      for (uint64_t i = 0; i < entsize; ++i)
+      for (section_size_type i = 0; i < entsize; ++i)
        {
          result &= (size_t) *p++;
          result *= 1099511628211ULL;
@@ -159,7 +329,7 @@ Output_merge_data::Merge_data_hash::operator()(Merge_data_key k) const
   else
     {
       size_t result = 2166136261UL;
-      for (uint64_t i = 0; i < entsize; ++i)
+      for (section_size_type i = 0; i < entsize; ++i)
        {
          result ^= (size_t) *p++;
          result *= 16777619UL;
@@ -184,8 +354,10 @@ Output_merge_data::Merge_data_eq::operator()(Merge_data_key k1,
 void
 Output_merge_data::add_constant(const unsigned char* p)
 {
-  uint64_t entsize = this->entsize();
-  uint64_t addsize = std::max(entsize, this->addralign());
+  section_size_type ent_size = convert_to_section_size_type(this->entsize());
+  section_size_type addr_align =
+    convert_to_section_size_type(this->addralign());
+  section_size_type addsize = std::max(ent_size, addr_align);
   if (this->len_ + addsize > this->alc_)
     {
       if (this->alc_ == 0)
@@ -197,9 +369,9 @@ Output_merge_data::add_constant(const unsigned char* p)
        gold_nomem();
     }
 
-  memcpy(this->p_ + this->len_, p, entsize);
-  if (addsize > entsize)
-    memset(this->p_ + this->len_ + entsize, 0, addsize - entsize);
+  memcpy(this->p_ + this->len_, p, ent_size);
+  if (addsize > ent_size)
+    memset(this->p_ + this->len_ + ent_size, 0, addsize - ent_size);
   this->len_ += addsize;
 }
 
@@ -211,15 +383,17 @@ Output_merge_data::add_constant(const unsigned char* p)
 bool
 Output_merge_data::do_add_input_section(Relobj* object, unsigned int shndx)
 {
-  off_t len;
+  section_size_type len;
   const unsigned char* p = object->section_contents(shndx, &len, false);
 
-  uint64_t entsize = this->entsize();
+  section_size_type ent_size = convert_to_section_size_type(this->entsize());
 
-  if (len % entsize != 0)
+  if (len % ent_size != 0)
     return false;
 
-  for (off_t i = 0; i < len; i += entsize, p += entsize)
+  this->input_count_ += len / ent_size;
+
+  for (section_size_type i = 0; i < len; i += ent_size, p += ent_size)
     {
       // Add the constant to the section contents.  If we find that it
       // is already in the hash table, we will remove it again.
@@ -232,12 +406,12 @@ Output_merge_data::do_add_input_section(Relobj* object, unsigned int shndx)
       if (!ins.second)
        {
          // Key was already present.  Remove the copy we just added.
-         this->len_ -= entsize;
+         this->len_ -= ent_size;
          k = *ins.first;
        }
 
       // Record the offset of this constant in the output section.
-      this->add_mapping(object, shndx, i, entsize, k);
+      this->add_mapping(object, shndx, i, ent_size, k);
     }
 
   return true;
@@ -247,7 +421,7 @@ Output_merge_data::do_add_input_section(Relobj* object, unsigned int shndx)
 // constants.
 
 void
-Output_merge_data::do_set_address(uint64_t, off_t)
+Output_merge_data::set_final_data_size()
 {
   // Release the memory we don't need.
   this->p_ = static_cast<unsigned char*>(realloc(this->p_, this->len_));
@@ -264,6 +438,26 @@ Output_merge_data::do_write(Output_file* of)
   of->write(this->offset(), this->p_, this->len_);
 }
 
+// Write the data to a buffer.
+
+void
+Output_merge_data::do_write_to_buffer(unsigned char* buffer)
+{
+  memcpy(buffer, this->p_, this->len_);
+}
+
+// Print merge stats to stderr.
+
+void
+Output_merge_data::do_print_merge_stats(const char* section_name)
+{
+  fprintf(stderr,
+         _("%s: %s merged constants size: %lu; input: %zu; output: %zu\n"),
+         program_name, section_name,
+         static_cast<unsigned long>(this->entsize()),
+         this->input_count_, this->hashtable_.size());
+}
+
 // Class Output_merge_string.
 
 // Add an input section to a merged string section.
@@ -273,10 +467,11 @@ bool
 Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
                                                     unsigned int shndx)
 {
-  off_t len;
+  section_size_type len;
   const unsigned char* pdata = object->section_contents(shndx, &len, false);
 
   const Char_type* p = reinterpret_cast<const Char_type*>(pdata);
+  const Char_type* pend = p + len / sizeof(Char_type);
 
   if (len % sizeof(Char_type) != 0)
     {
@@ -285,43 +480,49 @@ Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
       return false;
     }
 
+  size_t count = 0;
+
   // The index I is in bytes, not characters.
-  off_t i = 0;
+  section_size_type i = 0;
   while (i < len)
     {
-      off_t plen = 0;
-      for (const Char_type* pl = p; *pl != 0; ++pl)
+      const Char_type* pl;
+      for (pl = p; *pl != 0; ++pl)
        {
-          // The length PLEN is in characters, not bytes.
-         ++plen;
-         if (i + plen * static_cast<off_t>(sizeof(Char_type)) >= len)
+         if (pl >= pend)
            {
-             object->error(_("entry in mergeable string section "
-                             "not null terminated"));
+             gold_warning(_("%s: last entry in mergeable string section '%s' "
+                            "not null terminated"),
+                          object->name().c_str(),
+                          object->section_name(shndx).c_str());
              break;
            }
        }
 
-      const Char_type* str = this->stringpool_.add(p, true, NULL);
+      Stringpool::Key key;
+      const Char_type* str = this->stringpool_.add_with_length(p, pl - p, true,
+                                                              &key);
 
-      off_t bytelen_with_null = (plen + 1) * sizeof(Char_type);
+      section_size_type bytelen_with_null = ((pl - p) + 1) * sizeof(Char_type);
       this->merged_strings_.push_back(Merged_string(object, shndx, i, str,
-                                                   bytelen_with_null));
+                                                   bytelen_with_null, key));
 
-      p += plen + 1;
+      p = pl + 1;
       i += bytelen_with_null;
+      ++count;
     }
 
+  this->input_count_ += count;
+
   return true;
 }
 
-// Set the final data size of a merged string section.  This is where
-// we finalize the mappings from the input sections to the output
-// section.
+// Finalize the mappings from the input sections to the output
+// section, and return the final data size.
 
 template<typename Char_type>
-void
-Output_merge_string<Char_type>::do_set_address(uint64_t, off_t)
+section_size_type
+Output_merge_string<Char_type>::finalize_merged_data()
 {
   this->stringpool_.set_string_offsets();
 
@@ -329,13 +530,26 @@ Output_merge_string<Char_type>::do_set_address(uint64_t, off_t)
         this->merged_strings_.begin();
        p != this->merged_strings_.end();
        ++p)
-    this->add_mapping(p->object, p->shndx, p->offset, p->length,
-                     this->stringpool_.get_offset(p->string));
-
-  this->set_data_size(this->stringpool_.get_strtab_size());
+    {
+      section_offset_type soffset =
+       this->stringpool_.get_offset_from_key(p->stringpool_key);
+      this->add_mapping(p->object, p->shndx, p->offset, p->length, soffset);
+    }
 
-  // Save some memory.
+  // Save some memory.  This also ensures that this function will work
+  // if called twice, as may happen if Layout::set_segment_offsets
+  // finds a better alignment.
   this->merged_strings_.clear();
+
+  return this->stringpool_.get_strtab_size();
+}
+
+template<typename Char_type>
+void
+Output_merge_string<Char_type>::set_final_data_size()
+{
+  const off_t final_data_size = this->finalize_merged_data();
+  this->set_data_size(final_data_size);
 }
 
 // Write out a merged string section.
@@ -347,6 +561,60 @@ Output_merge_string<Char_type>::do_write(Output_file* of)
   this->stringpool_.write(of, this->offset());
 }
 
+// Write a merged string section to a buffer.
+
+template<typename Char_type>
+void
+Output_merge_string<Char_type>::do_write_to_buffer(unsigned char* buffer)
+{
+  this->stringpool_.write_to_buffer(buffer, this->data_size());
+}
+
+// Return the name of the types of string to use with
+// do_print_merge_stats.
+
+template<typename Char_type>
+const char*
+Output_merge_string<Char_type>::string_name()
+{
+  gold_unreachable();
+  return NULL;
+}
+
+template<>
+const char*
+Output_merge_string<char>::string_name()
+{
+  return "strings";
+}
+
+template<>
+const char*
+Output_merge_string<uint16_t>::string_name()
+{
+  return "16-bit strings";
+}
+
+template<>
+const char*
+Output_merge_string<uint32_t>::string_name()
+{
+  return "32-bit strings";
+}
+
+// Print merge stats to stderr.
+
+template<typename Char_type>
+void
+Output_merge_string<Char_type>::do_print_merge_stats(const char* section_name)
+{
+  char buf[200];
+  snprintf(buf, sizeof buf, "%s merged %s", section_name, this->string_name());
+  fprintf(stderr, _("%s: %s input: %zu\n"),
+         program_name, buf, this->input_count_);
+  this->stringpool_.print_stats(buf);
+}
+
 // Instantiate the templates we need.
 
 template
@@ -358,4 +626,22 @@ class Output_merge_string<uint16_t>;
 template
 class Output_merge_string<uint32_t>;
 
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+template
+void
+Object_merge_map::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>*);
+#endif
+
+#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
+template
+void
+Object_merge_map::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>*);
+#endif
+
 } // End namespace gold.
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