// merge.cc -- handle section merging for gold
+// Copyright 2006, 2007 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
{
-// 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.
+// For each object with merge sections, we store an Object_merge_map.
+// This is used to map locations in input sections to a merged output
+// section. The output section itself is not recorded here--it can be
+// found in the map_to_output_ field of the Object.
-bool
-Output_merge_base::Merge_key_less::operator()(const Merge_key& mk1,
- const Merge_key& mk2) const
+class Object_merge_map
{
- // 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)
- return mk1.object->name() < mk2.object->name();
- if (mk1.shndx != mk2.shndx)
- return mk1.shndx < mk2.shndx;
- return mk1.offset < mk2.offset;
+ public:
+ Object_merge_map()
+ : first_shnum_(-1U), first_map_(),
+ second_shnum_(-1U), second_map_(),
+ section_merge_maps_()
+ { }
+
+ ~Object_merge_map();
+
+ // Add a mapping for MERGE_MAP, for the bytes from OFFSET to OFFSET
+ // + LENGTH in the input section SHNDX to OUTPUT_OFFSET in the
+ // output section. An OUTPUT_OFFSET of -1 means that the bytes are
+ // discarded.
+ void
+ add_mapping(const Merge_map*, unsigned int shndx, section_offset_type offset,
+ section_size_type length, section_offset_type output_offset);
+
+ // Get the output offset for an input address in MERGE_MAP. The
+ // input address is at offset OFFSET in section SHNDX. This sets
+ // *OUTPUT_OFFSET to the offset in the output section; this will be
+ // -1 if the bytes are not being copied to the output. This returns
+ // true if the mapping is known, false otherwise.
+ bool
+ get_output_offset(const Merge_map*, unsigned int shndx,
+ section_offset_type offset,
+ section_offset_type *output_offset);
+
+ private:
+ // Map input section offsets to a length and an output section
+ // offset. An output section offset of -1 means that this part of
+ // the input section is being discarded.
+ struct Input_merge_entry
+ {
+ // The offset in the input section.
+ section_offset_type input_offset;
+ // The length.
+ section_size_type length;
+ // The offset in the output section.
+ section_offset_type output_offset;
+ };
+
+ // A less-than comparison routine for Input_merge_entry.
+ struct Input_merge_compare
+ {
+ bool
+ operator()(const Input_merge_entry& i1, const Input_merge_entry& i2) const
+ { return i1.input_offset < i2.input_offset; }
+ };
+
+ // A list of entries for a particular section.
+ struct Input_merge_map
+ {
+ // The Merge_map for this section.
+ const Merge_map* merge_map;
+ // The list of mappings.
+ std::vector<Input_merge_entry> entries;
+ // Whether the ENTRIES field is sorted by input_offset.
+ bool sorted;
+
+ Input_merge_map()
+ : merge_map(NULL), entries(), sorted(true)
+ { }
+ };
+
+ // Map input section indices to merge maps.
+ typedef std::map<unsigned int, Input_merge_map*> Section_merge_maps;
+
+ // Return a pointer to the Input_merge_map to use for the input
+ // section SHNDX, or NULL.
+ Input_merge_map*
+ get_input_merge_map(unsigned int shndx);
+
+ // Get or make the the Input_merge_map to use for the section SHNDX
+ // with MERGE_MAP.
+ Input_merge_map*
+ get_or_make_input_merge_map(const Merge_map* merge_map, unsigned int shndx);
+
+ // Any given object file will normally only have a couple of input
+ // sections with mergeable contents. So we keep the first two input
+ // section numbers inline, and push any further ones into a map. A
+ // value of -1U in first_shnum_ or second_shnum_ means that we don't
+ // have a corresponding entry.
+ unsigned int first_shnum_;
+ Input_merge_map first_map_;
+ unsigned int second_shnum_;
+ Input_merge_map second_map_;
+ Section_merge_maps section_merge_maps_;
+};
+
+// 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;
}
-// Add a mapping from an OFFSET in input section SHNDX in object
-// OBJECT to an OUTPUT_OFFSET in a merged output section. This
-// manages the mapping used to resolve relocations against merged
-// sections.
+// 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 donw 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
-Output_merge_base::add_mapping(Relobj* object, unsigned int shndx,
- off_t offset, off_t output_offset)
+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)
{
- Merge_key mk;
- mk.object = object;
- mk.shndx = shndx;
- mk.offset = offset;
- std::pair<Merge_map::iterator, bool> ins =
- this->merge_map_.insert(std::make_pair(mk, output_offset));
- gold_assert(ins.second);
+ 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);
}
-// Return the output address for an input address. The input address
-// is at offset OFFSET in section SHNDX in OBJECT.
-// OUTPUT_SECTION_ADDRESS is the address of the output section. If we
-// know the address, set *POUTPUT and return true. Otherwise return
-// false.
+// Get the output offset for an input address.
bool
-Output_merge_base::do_output_address(const Relobj* object, unsigned int shndx,
- off_t offset,
- uint64_t output_section_address,
- uint64_t* poutput) 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)
{
- gold_assert(output_section_address == this->address());
-
- Merge_key mk;
- mk.object = object;
- mk.shndx = shndx;
- mk.offset = offset;
- Merge_map::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->first.object != object
- || p->first.shndx != shndx
- || p->first.offset != offset)
+ Input_merge_map* map = this->get_input_merge_map(shndx);
+ if (map == NULL || map->merge_map != merge_map)
+ return false;
+
+ if (!map->sorted)
{
- if (p == this->merge_map_.begin())
+ 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 (p->first.object != object || p->first.shndx != shndx)
+ if (input_offset - p->input_offset
+ >= static_cast<section_offset_type>(p->length))
return false;
- // Any input section is fully mapped: we don't need to know the size
- // of the range starting at P->FIRST.OFFSET.
- *poutput = output_section_address + p->second + (offset - p->first.offset);
+ *output_offset = p->output_offset;
+ if (*output_offset != -1)
+ *output_offset += (input_offset - p->input_offset);
return true;
}
+// 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.
+
+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 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);
+}
+
+// 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);
+}
+
+// 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);
- 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;
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;
void
Output_merge_data::add_constant(const unsigned char* p)
{
- uint64_t entsize = this->entsize();
- if (this->len_ + entsize > this->alc_)
+ 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 * entsize;
+ this->alc_ = 128 * addsize;
else
this->alc_ *= 2;
this->p_ = static_cast<unsigned char*>(realloc(this->p_, this->alc_));
if (this->p_ == NULL)
- gold_fatal("out of memory", true);
+ gold_nomem();
}
memcpy(this->p_ + this->len_, p, entsize);
- this->len_ += 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
bool
Output_merge_data::do_add_input_section(Relobj* object, unsigned int shndx)
{
- off_t len;
- const unsigned char* p = object->section_contents(shndx, &len);
+ section_size_type len;
+ const unsigned char* p = object->section_contents(shndx, &len, false);
- uint64_t entsize = this->entsize();
+ section_size_type entsize = convert_to_section_size_type(this->entsize());
if (len % entsize != 0)
return false;
- for (off_t i = 0; i < len; i += entsize, p += 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.
}
// Record the offset of this constant in the output section.
- this->add_mapping(object, shndx, i, k);
+ this->add_mapping(object, shndx, i, entsize, k);
}
return true;
// 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_));
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_);
+}
+
+// Class Output_merge_string.
+
// Add an input section to a merged string section.
template<typename Char_type>
Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
unsigned int shndx)
{
- off_t len;
- const unsigned char* pdata = object->section_contents(shndx, &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;
if (len % sizeof(Char_type) != 0)
{
- fprintf(stderr,
- _("%s: %s: mergeable string section length not multiple of "
- "character size\n"),
- program_name, object->name().c_str());
- gold_exit(false);
+ object->error(_("mergeable string section length not multiple of "
+ "character size"));
+ return false;
}
- len /= sizeof(Char_type);
- off_t i = 0;
+ // The index I is in bytes, not characters.
+ 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)
{
- ++plen;
- if (i + plen >= len)
+ if (pl >= pend)
{
- fprintf(stderr,
- _("%s: %s: entry in mergeable string section "
- "not null terminated\n"),
- program_name, object->name().c_str());
- gold_exit(false);
+ object->error(_("entry in mergeable string section "
+ "not null terminated"));
+ break;
}
}
- const Char_type* str = this->stringpool_.add(p, NULL);
+ const Char_type* str = this->stringpool_.add_prefix(p, pl - p, NULL);
- this->merged_strings_.push_back(Merged_string(object, shndx, i, str));
+ 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));
- p += plen + 1;
- i += plen + 1;
+ p = pl + 1;
+ i += bytelen_with_null;
}
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();
this->merged_strings_.begin();
p != this->merged_strings_.end();
++p)
- this->add_mapping(p->object, p->shndx, p->offset,
+ 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());
-
// Save some memory.
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.
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());
+}
+
// Instantiate the templates we need.
template
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