// merge.cc -- handle section merging for gold
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "gold.h"
#include <cstdlib>
+#include <algorithm>
#include "merge.h"
+#include "compressed_output.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.
+// Class Object_merge_map.
-bool
-Output_merge_base::Merge_key_less::operator()(const Merge_key& mk1,
- const Merge_key& mk2) const
+// Destructor.
+
+Object_merge_map::~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;
+ 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.
+
+const Object_merge_map::Input_merge_map*
+Object_merge_map::get_input_merge_map(unsigned int shndx) const
+{
+ gold_assert(shndx != -1U);
+ const Section_merge_maps &maps = this->section_merge_maps_;
+ for (Section_merge_maps::const_iterator i = maps.begin(), e = maps.end();
+ i != e; ++i)
+ {
+ if (i->first == shndx)
+ return i->second;
+ }
+ return NULL;
}
-// 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 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 Output_section_data* output_data, 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->output_data == output_data);
+ return map;
+ }
+
+ Input_merge_map* new_map = new Input_merge_map;
+ new_map->output_data = output_data;
+ Section_merge_maps &maps = this->section_merge_maps_;
+ maps.push_back(std::make_pair(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 Output_section_data* output_data,
+ 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(output_data, shndx);
+ map->add_mapping(input_offset, length, output_offset);
}
-// 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.
+void
+Object_merge_map::Input_merge_map::add_mapping(
+ section_offset_type input_offset, section_size_type length,
+ section_offset_type output_offset) {
+ // Try to merge the new entry in the last one we saw.
+ if (!this->entries.empty())
+ {
+ Input_merge_entry& entry(this->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));
+ this->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;
+ this->entries.push_back(entry);
+}
+
+// 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(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)
+ return false;
+
+ if (!map->sorted)
{
- if (p == this->merge_map_.begin())
- return false;
- --p;
+ std::sort(map->entries.begin(), map->entries.end(),
+ Input_merge_compare());
+ map->sorted = true;
}
- if (p->first.object != object || p->first.shndx != shndx)
+ Input_merge_entry entry;
+ entry.input_offset = input_offset;
+ std::vector<Input_merge_entry>::const_iterator p =
+ std::upper_bound(map->entries.begin(), map->entries.end(),
+ entry, Input_merge_compare());
+ 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;
- // 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;
}
+// Return whether this is the merge map for section SHNDX.
+
+const Output_section_data*
+Object_merge_map::find_merge_section(unsigned int shndx) const {
+ const Object_merge_map::Input_merge_map* map =
+ this->get_input_merge_map(shndx);
+ if (map == NULL)
+ return NULL;
+ return map->output_data;
+}
+
+// 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 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 object->merge_output_offset(shndx, offset, poutput);
+}
+
+// Record a merged input section for script processing.
+
+void
+Output_merge_base::record_input_section(Relobj* relobj, unsigned int shndx)
+{
+ gold_assert(this->keeps_input_sections_ && relobj != NULL);
+ // If this is the first input section, record it. We need do this because
+ // this->input_sections_ is unordered.
+ if (this->first_relobj_ == NULL)
+ {
+ this->first_relobj_ = relobj;
+ this->first_shndx_ = shndx;
+ }
+
+ std::pair<Input_sections::iterator, bool> result =
+ this->input_sections_.insert(Section_id(relobj, shndx));
+ // We should insert a merge section once only.
+ gold_assert(result.second);
+}
+
+// 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;
+ bool is_new;
+ const unsigned char* p = object->decompressed_section_contents(shndx, &len,
+ &is_new);
- uint64_t entsize = this->entsize();
+ section_size_type entsize = convert_to_section_size_type(this->entsize());
if (len % entsize != 0)
- return false;
+ {
+ if (is_new)
+ delete[] p;
+ return false;
+ }
+
+ this->input_count_ += len / entsize;
- for (off_t i = 0; i < len; i += entsize, p += entsize)
+ Object_merge_map* merge_map = object->get_or_create_merge_map();
+ Object_merge_map::Input_merge_map* input_merge_map =
+ merge_map->get_or_make_input_merge_map(this, shndx);
+
+ 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);
+ input_merge_map->add_mapping(i, entsize, k);
}
+ // For script processing, we keep the input sections.
+ if (this->keeps_input_sections())
+ record_input_section(object, shndx);
+
+ if (is_new)
+ delete[] p;
+
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_));
- gold_assert(this->p_ != NULL);
+ // An Output_merge_data object may be empty and realloc is allowed
+ // to return a NULL pointer in this case. An Output_merge_data is empty
+ // if all its input sections have sizes that are not multiples of entsize.
+ gold_assert(this->p_ != NULL || this->len_ == 0);
this->set_data_size(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_);
+}
+
+// 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>
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 sec_len;
+ bool is_new;
+ uint64_t addralign = this->addralign();
+ const unsigned char* pdata = object->decompressed_section_contents(shndx,
+ &sec_len,
+ &is_new,
+ &addralign);
const Char_type* p = reinterpret_cast<const Char_type*>(pdata);
+ const Char_type* pend = p + sec_len / sizeof(Char_type);
+ const Char_type* pend0 = pend;
- if (len % sizeof(Char_type) != 0)
+ if (sec_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"));
+ if (is_new)
+ delete[] pdata;
+ return false;
}
- len /= sizeof(Char_type);
- off_t i = 0;
- while (i < len)
+ if (pend[-1] != 0)
{
- off_t plen = 0;
- for (const Char_type* pl = p; *pl != 0; ++pl)
- {
- ++plen;
- if (i + plen >= len)
- {
- fprintf(stderr,
- _("%s: %s: entry in mergeable string section "
- "not null terminated\n"),
- program_name, object->name().c_str());
- gold_exit(false);
- }
- }
+ gold_warning(_("%s: last entry in mergeable string section '%s' "
+ "not null terminated"),
+ object->name().c_str(),
+ object->section_name(shndx).c_str());
+ // Find the end of the last NULL-terminated string in the buffer.
+ while (pend0 > p && pend0[-1] != 0)
+ --pend0;
+ }
- const Char_type* str = this->stringpool_.add(p, NULL);
+ Merged_strings_list* merged_strings_list =
+ new Merged_strings_list(object, shndx);
+ this->merged_strings_lists_.push_back(merged_strings_list);
+ Merged_strings& merged_strings = merged_strings_list->merged_strings;
- this->merged_strings_.push_back(Merged_string(object, shndx, i, str));
+ // Count the number of non-null strings in the section and size the list.
+ size_t count = 0;
+ const Char_type* pt = p;
+ while (pt < pend0)
+ {
+ size_t len = string_length(pt);
+ if (len != 0)
+ ++count;
+ pt += len + 1;
+ }
+ if (pend0 < pend)
+ ++count;
+ merged_strings.reserve(count + 1);
+
+ // The index I is in bytes, not characters.
+ section_size_type i = 0;
- p += plen + 1;
- i += plen + 1;
+ // We assume here that the beginning of the section is correctly
+ // aligned, so each string within the section must retain the same
+ // modulo.
+ uintptr_t init_align_modulo = (reinterpret_cast<uintptr_t>(pdata)
+ & (addralign - 1));
+ bool has_misaligned_strings = false;
+
+ while (p < pend)
+ {
+ size_t len = p < pend0 ? string_length(p) : pend - p;
+
+ // Within merge input section each string must be aligned.
+ if (len != 0
+ && ((reinterpret_cast<uintptr_t>(p) & (addralign - 1))
+ != init_align_modulo))
+ has_misaligned_strings = true;
+
+ Stringpool::Key key;
+ this->stringpool_.add_with_length(p, len, true, &key);
+
+ merged_strings.push_back(Merged_string(i, key));
+ p += len + 1;
+ i += (len + 1) * sizeof(Char_type);
}
+ // Record the last offset in the input section so that we can
+ // compute the length of the last string.
+ merged_strings.push_back(Merged_string(i, 0));
+
+ this->input_count_ += count;
+ this->input_size_ += i;
+
+ if (has_misaligned_strings)
+ gold_warning(_("%s: section %s contains incorrectly aligned strings;"
+ " the alignment of those strings won't be preserved"),
+ object->name().c_str(),
+ object->section_name(shndx).c_str());
+
+ // For script processing, we keep the input sections.
+ if (this->keeps_input_sections())
+ record_input_section(object, shndx);
+
+ if (is_new)
+ delete[] pdata;
+
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();
- for (typename Merged_strings::const_iterator p =
- this->merged_strings_.begin();
- p != this->merged_strings_.end();
- ++p)
- this->add_mapping(p->object, p->shndx, p->offset,
- this->stringpool_.get_offset(p->string));
+ for (typename Merged_strings_lists::const_iterator l =
+ this->merged_strings_lists_.begin();
+ l != this->merged_strings_lists_.end();
+ ++l)
+ {
+ section_offset_type last_input_offset = 0;
+ section_offset_type last_output_offset = 0;
+ Relobj *object = (*l)->object;
+ Object_merge_map* merge_map = object->get_or_create_merge_map();
+ Object_merge_map::Input_merge_map* input_merge_map =
+ merge_map->get_or_make_input_merge_map(this, (*l)->shndx);
+
+ for (typename Merged_strings::const_iterator p =
+ (*l)->merged_strings.begin();
+ p != (*l)->merged_strings.end();
+ ++p)
+ {
+ section_size_type length = p->offset - last_input_offset;
+ if (length > 0)
+ input_merge_map->add_mapping(last_input_offset, length,
+ last_output_offset);
+ last_input_offset = p->offset;
+ if (p->stringpool_key != 0)
+ last_output_offset =
+ this->stringpool_.get_offset_from_key(p->stringpool_key);
+ }
+ delete *l;
+ }
- this->set_data_size(this->stringpool_.get_strtab_size());
+ // 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_lists_.clear();
- // 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());
+}
+
+// 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 bytes: %zu\n"),
+ program_name, buf, this->input_size_);
+ fprintf(stderr, _("%s: %s input strings: %zu\n"),
+ program_name, buf, this->input_count_);
+ this->stringpool_.print_stats(buf);
+}
+
// Instantiate the templates we need.
template
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 / deliverable / binutils-gdb.git / blobdiff