--- /dev/null
+// merge.cc -- handle section merging for gold
+
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include "gold.h"
+
+#include <cstdlib>
+#include <algorithm>
+
+#include "merge.h"
+
+namespace gold
+{
+
+// Class Object_merge_map.
+
+// 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
+Object_merge_map::get_output_offset(const Merge_map* merge_map,
+ unsigned int shndx,
+ section_offset_type input_offset,
+ section_offset_type *output_offset)
+{
+ 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)
+ {
+ 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));
+ }
+}
+
+// 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 merged data
+// in an output section.
+
+void
+Merge_map::add_mapping(Relobj* object, unsigned int shndx,
+ section_offset_type offset, section_size_type length,
+ section_offset_type output_offset)
+{
+ 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 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,
+ section_offset_type offset,
+ section_offset_type* output_offset) const
+{
+ 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);
+}
+
+// Return whether this is the merge section for SHNDX in OBJECT.
+
+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.
+
+// Return the output offset for an input offset. The input address is
+// at offset OFFSET in section SHNDX in OBJECT. If we know the
+// offset, set *POUTPUT and return true. Otherwise return false.
+
+bool
+Output_merge_base::do_output_offset(const Relobj* object,
+ unsigned int shndx,
+ section_offset_type offset,
+ section_offset_type* poutput) const
+{
+ return this->merge_map_.get_output_offset(object, shndx, offset, 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.
+
+// Compute the hash code for a fixed-size constant.
+
+size_t
+Output_merge_data::Merge_data_hash::operator()(Merge_data_key k) const
+{
+ const unsigned char* p = this->pomd_->constant(k);
+ 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 (section_size_type i = 0; i < entsize; ++i)
+ {
+ result &= (size_t) *p++;
+ result *= 1099511628211ULL;
+ }
+ return result;
+ }
+ else
+ {
+ size_t result = 2166136261UL;
+ for (section_size_type i = 0; i < entsize; ++i)
+ {
+ result ^= (size_t) *p++;
+ result *= 16777619UL;
+ }
+ return result;
+ }
+}
+
+// Return whether one hash table key equals another.
+
+bool
+Output_merge_data::Merge_data_eq::operator()(Merge_data_key k1,
+ Merge_data_key k2) const
+{
+ const unsigned char* p1 = this->pomd_->constant(k1);
+ const unsigned char* p2 = this->pomd_->constant(k2);
+ return memcmp(p1, p2, this->pomd_->entsize()) == 0;
+}
+
+// Add a constant to the end of the section contents.
+
+void
+Output_merge_data::add_constant(const unsigned char* p)
+{
+ section_size_type entsize = convert_to_section_size_type(this->entsize());
+ section_size_type addralign =
+ convert_to_section_size_type(this->addralign());
+ section_size_type addsize = std::max(entsize, addralign);
+ if (this->len_ + addsize > this->alc_)
+ {
+ if (this->alc_ == 0)
+ this->alc_ = 128 * addsize;
+ else
+ this->alc_ *= 2;
+ this->p_ = static_cast<unsigned char*>(realloc(this->p_, this->alc_));
+ if (this->p_ == NULL)
+ gold_nomem();
+ }
+
+ memcpy(this->p_ + this->len_, p, entsize);
+ if (addsize > entsize)
+ memset(this->p_ + this->len_ + entsize, 0, addsize - entsize);
+ this->len_ += addsize;
+}
+
+// Add the input section SHNDX in OBJECT to a merged output section
+// which holds fixed length constants. Return whether we were able to
+// handle the section; if not, it will be linked as usual without
+// constant merging.
+
+bool
+Output_merge_data::do_add_input_section(Relobj* object, unsigned int shndx)
+{
+ section_size_type len;
+ const unsigned char* p = object->section_contents(shndx, &len, false);
+
+ section_size_type entsize = convert_to_section_size_type(this->entsize());
+
+ if (len % entsize != 0)
+ return false;
+
+ this->input_count_ += len / entsize;
+
+ for (section_size_type i = 0; i < len; i += entsize, p += entsize)
+ {
+ // Add the constant to the section contents. If we find that it
+ // is already in the hash table, we will remove it again.
+ Merge_data_key k = this->len_;
+ this->add_constant(p);
+
+ std::pair<Merge_data_hashtable::iterator, bool> ins =
+ this->hashtable_.insert(k);
+
+ if (!ins.second)
+ {
+ // Key was already present. Remove the copy we just added.
+ this->len_ -= entsize;
+ k = *ins.first;
+ }
+
+ // Record the offset of this constant in the output section.
+ this->add_mapping(object, shndx, i, entsize, k);
+ }
+
+ return true;
+}
+
+// Set the final data size in a merged output section with fixed size
+// constants.
+
+void
+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_));
+ gold_assert(this->p_ != NULL);
+ this->set_data_size(this->len_);
+}
+
+// Write the data of a merged output section with fixed size constants
+// to the file.
+
+void
+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.
+
+template<typename Char_type>
+bool
+Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
+ unsigned int shndx)
+{
+ 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)
+ {
+ object->error(_("mergeable string section length not multiple of "
+ "character size"));
+ return false;
+ }
+
+ size_t count = 0;
+
+ // The index I is in bytes, not characters.
+ section_size_type i = 0;
+ while (i < len)
+ {
+ const Char_type* pl;
+ for (pl = p; *pl != 0; ++pl)
+ {
+ if (pl >= pend)
+ {
+ gold_warning(_("%s: last entry in mergeable string section '%s' "
+ "not null terminated"),
+ object->name().c_str(),
+ object->section_name(shndx).c_str());
+ break;
+ }
+ }
+
+ Stringpool::Key key;
+ const Char_type* str = this->stringpool_.add_with_length(p, pl - p, true,
+ &key);
+
+ 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, key));
+
+ p = pl + 1;
+ i += bytelen_with_null;
+ ++count;
+ }
+
+ this->input_count_ += count;
+
+ return true;
+}
+
+// Finalize the mappings from the input sections to the output
+// section, and return the final data size.
+
+template<typename Char_type>
+section_size_type
+Output_merge_string<Char_type>::finalize_merged_data()
+{
+ this->stringpool_.set_string_offsets();
+
+ for (typename Merged_strings::const_iterator p =
+ this->merged_strings_.begin();
+ p != this->merged_strings_.end();
+ ++p)
+ {
+ section_offset_type offset =
+ this->stringpool_.get_offset_from_key(p->stringpool_key);
+ this->add_mapping(p->object, p->shndx, p->offset, p->length, offset);
+ }
+
+ // 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.
+
+template<typename Char_type>
+void
+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
+class Output_merge_string<char>;
+
+template
+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.
projects / msp430-binutils.git / blobdiff