// layout.cc -- lay out output file sections for gold
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include <cstring>
#include <algorithm>
#include <iostream>
+#include <fstream>
#include <utility>
#include <fcntl.h>
+#include <fnmatch.h>
#include <unistd.h>
#include "libiberty.h"
#include "md5.h"
#include "reduced_debug_output.h"
#include "reloc.h"
#include "descriptors.h"
-#include "layout.h"
#include "plugin.h"
+#include "incremental.h"
+#include "layout.h"
namespace gold
{
+// Class Free_list.
+
+// The total number of free lists used.
+unsigned int Free_list::num_lists = 0;
+// The total number of free list nodes used.
+unsigned int Free_list::num_nodes = 0;
+// The total number of calls to Free_list::remove.
+unsigned int Free_list::num_removes = 0;
+// The total number of nodes visited during calls to Free_list::remove.
+unsigned int Free_list::num_remove_visits = 0;
+// The total number of calls to Free_list::allocate.
+unsigned int Free_list::num_allocates = 0;
+// The total number of nodes visited during calls to Free_list::allocate.
+unsigned int Free_list::num_allocate_visits = 0;
+
+// Initialize the free list. Creates a single free list node that
+// describes the entire region of length LEN. If EXTEND is true,
+// allocate() is allowed to extend the region beyond its initial
+// length.
+
+void
+Free_list::init(off_t len, bool extend)
+{
+ this->list_.push_front(Free_list_node(0, len));
+ this->last_remove_ = this->list_.begin();
+ this->extend_ = extend;
+ this->length_ = len;
+ ++Free_list::num_lists;
+ ++Free_list::num_nodes;
+}
+
+// Remove a chunk from the free list. Because we start with a single
+// node that covers the entire section, and remove chunks from it one
+// at a time, we do not need to coalesce chunks or handle cases that
+// span more than one free node. We expect to remove chunks from the
+// free list in order, and we expect to have only a few chunks of free
+// space left (corresponding to files that have changed since the last
+// incremental link), so a simple linear list should provide sufficient
+// performance.
+
+void
+Free_list::remove(off_t start, off_t end)
+{
+ if (start == end)
+ return;
+ gold_assert(start < end);
+
+ ++Free_list::num_removes;
+
+ Iterator p = this->last_remove_;
+ if (p->start_ > start)
+ p = this->list_.begin();
+
+ for (; p != this->list_.end(); ++p)
+ {
+ ++Free_list::num_remove_visits;
+ // Find a node that wholly contains the indicated region.
+ if (p->start_ <= start && p->end_ >= end)
+ {
+ // Case 1: the indicated region spans the whole node.
+ // Add some fuzz to avoid creating tiny free chunks.
+ if (p->start_ + 3 >= start && p->end_ <= end + 3)
+ p = this->list_.erase(p);
+ // Case 2: remove a chunk from the start of the node.
+ else if (p->start_ + 3 >= start)
+ p->start_ = end;
+ // Case 3: remove a chunk from the end of the node.
+ else if (p->end_ <= end + 3)
+ p->end_ = start;
+ // Case 4: remove a chunk from the middle, and split
+ // the node into two.
+ else
+ {
+ Free_list_node newnode(p->start_, start);
+ p->start_ = end;
+ this->list_.insert(p, newnode);
+ ++Free_list::num_nodes;
+ }
+ this->last_remove_ = p;
+ return;
+ }
+ }
+
+ // Did not find a node containing the given chunk. This could happen
+ // because a small chunk was already removed due to the fuzz.
+ gold_debug(DEBUG_INCREMENTAL,
+ "Free_list::remove(%d,%d) not found",
+ static_cast<int>(start), static_cast<int>(end));
+}
+
+// Allocate a chunk of size LEN from the free list. Returns -1ULL
+// if a sufficiently large chunk of free space is not found.
+// We use a simple first-fit algorithm.
+
+off_t
+Free_list::allocate(off_t len, uint64_t align, off_t minoff)
+{
+ gold_debug(DEBUG_INCREMENTAL,
+ "Free_list::allocate(%08lx, %d, %08lx)",
+ static_cast<long>(len), static_cast<int>(align),
+ static_cast<long>(minoff));
+ if (len == 0)
+ return align_address(minoff, align);
+
+ ++Free_list::num_allocates;
+
+ for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
+ {
+ ++Free_list::num_allocate_visits;
+ off_t start = p->start_ > minoff ? p->start_ : minoff;
+ start = align_address(start, align);
+ off_t end = start + len;
+ if (end <= p->end_)
+ {
+ if (p->start_ + 3 >= start && p->end_ <= end + 3)
+ this->list_.erase(p);
+ else if (p->start_ + 3 >= start)
+ p->start_ = end;
+ else if (p->end_ <= end + 3)
+ p->end_ = start;
+ else
+ {
+ Free_list_node newnode(p->start_, start);
+ p->start_ = end;
+ this->list_.insert(p, newnode);
+ ++Free_list::num_nodes;
+ }
+ return start;
+ }
+ }
+ return -1;
+}
+
+// Dump the free list (for debugging).
+void
+Free_list::dump()
+{
+ gold_info("Free list:\n start end length\n");
+ for (Iterator p = this->list_.begin(); p != this->list_.end(); ++p)
+ gold_info(" %08lx %08lx %08lx", static_cast<long>(p->start_),
+ static_cast<long>(p->end_),
+ static_cast<long>(p->end_ - p->start_));
+}
+
+// Print the statistics for the free lists.
+void
+Free_list::print_stats()
+{
+ fprintf(stderr, _("%s: total free lists: %u\n"),
+ program_name, Free_list::num_lists);
+ fprintf(stderr, _("%s: total free list nodes: %u\n"),
+ program_name, Free_list::num_nodes);
+ fprintf(stderr, _("%s: calls to Free_list::remove: %u\n"),
+ program_name, Free_list::num_removes);
+ fprintf(stderr, _("%s: nodes visited: %u\n"),
+ program_name, Free_list::num_remove_visits);
+ fprintf(stderr, _("%s: calls to Free_list::allocate: %u\n"),
+ program_name, Free_list::num_allocates);
+ fprintf(stderr, _("%s: nodes visited: %u\n"),
+ program_name, Free_list::num_allocate_visits);
+}
+
+// Layout::Relaxation_debug_check methods.
+
+// Check that sections and special data are in reset states.
+// We do not save states for Output_sections and special Output_data.
+// So we check that they have not assigned any addresses or offsets.
+// clean_up_after_relaxation simply resets their addresses and offsets.
+void
+Layout::Relaxation_debug_check::check_output_data_for_reset_values(
+ const Layout::Section_list& sections,
+ const Layout::Data_list& special_outputs)
+{
+ for(Layout::Section_list::const_iterator p = sections.begin();
+ p != sections.end();
+ ++p)
+ gold_assert((*p)->address_and_file_offset_have_reset_values());
+
+ for(Layout::Data_list::const_iterator p = special_outputs.begin();
+ p != special_outputs.end();
+ ++p)
+ gold_assert((*p)->address_and_file_offset_have_reset_values());
+}
+
+// Save information of SECTIONS for checking later.
+
+void
+Layout::Relaxation_debug_check::read_sections(
+ const Layout::Section_list& sections)
+{
+ for(Layout::Section_list::const_iterator p = sections.begin();
+ p != sections.end();
+ ++p)
+ {
+ Output_section* os = *p;
+ Section_info info;
+ info.output_section = os;
+ info.address = os->is_address_valid() ? os->address() : 0;
+ info.data_size = os->is_data_size_valid() ? os->data_size() : -1;
+ info.offset = os->is_offset_valid()? os->offset() : -1 ;
+ this->section_infos_.push_back(info);
+ }
+}
+
+// Verify SECTIONS using previously recorded information.
+
+void
+Layout::Relaxation_debug_check::verify_sections(
+ const Layout::Section_list& sections)
+{
+ size_t i = 0;
+ for(Layout::Section_list::const_iterator p = sections.begin();
+ p != sections.end();
+ ++p, ++i)
+ {
+ Output_section* os = *p;
+ uint64_t address = os->is_address_valid() ? os->address() : 0;
+ off_t data_size = os->is_data_size_valid() ? os->data_size() : -1;
+ off_t offset = os->is_offset_valid()? os->offset() : -1 ;
+
+ if (i >= this->section_infos_.size())
+ {
+ gold_fatal("Section_info of %s missing.\n", os->name());
+ }
+ const Section_info& info = this->section_infos_[i];
+ if (os != info.output_section)
+ gold_fatal("Section order changed. Expecting %s but see %s\n",
+ info.output_section->name(), os->name());
+ if (address != info.address
+ || data_size != info.data_size
+ || offset != info.offset)
+ gold_fatal("Section %s changed.\n", os->name());
+ }
+}
+
// Layout_task_runner methods.
// Lay out the sections. This is called after all the input objects
this->layout_->print_to_mapfile(this->mapfile_);
}
- Output_file* of = new Output_file(parameters->options().output_file_name());
- if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
- of->set_is_temporary();
- of->open(file_size);
+ Output_file* of;
+ if (this->layout_->incremental_base() == NULL)
+ {
+ of = new Output_file(parameters->options().output_file_name());
+ if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
+ of->set_is_temporary();
+ of->open(file_size);
+ }
+ else
+ {
+ of = this->layout_->incremental_base()->output_file();
+ of->resize(file_size);
+ }
// Queue up the final set of tasks.
gold::queue_final_tasks(this->options_, this->input_objects_,
// Layout methods.
-Layout::Layout(const General_options& options, Script_options* script_options)
- : options_(options),
+Layout::Layout(int number_of_input_files, Script_options* script_options)
+ : number_of_input_files_(number_of_input_files),
script_options_(script_options),
namepool_(),
sympool_(),
segment_list_(),
section_list_(),
unattached_section_list_(),
- sections_are_attached_(false),
special_output_list_(),
section_headers_(NULL),
tls_segment_(NULL),
relro_segment_(NULL),
+ increase_relro_(0),
symtab_section_(NULL),
symtab_xindex_(NULL),
dynsym_section_(NULL),
dynsym_xindex_(NULL),
dynamic_section_(NULL),
+ dynamic_symbol_(NULL),
dynamic_data_(NULL),
eh_frame_section_(NULL),
eh_frame_data_(NULL),
debug_info_(NULL),
group_signatures_(),
output_file_size_(-1),
+ have_added_input_section_(false),
+ sections_are_attached_(false),
input_requires_executable_stack_(false),
input_with_gnu_stack_note_(false),
input_without_gnu_stack_note_(false),
has_static_tls_(false),
- any_postprocessing_sections_(false)
+ any_postprocessing_sections_(false),
+ resized_signatures_(false),
+ have_stabstr_section_(false),
+ incremental_inputs_(NULL),
+ record_output_section_data_from_script_(false),
+ script_output_section_data_list_(),
+ segment_states_(NULL),
+ relaxation_debug_check_(NULL),
+ incremental_base_(NULL),
+ free_list_()
{
// Make space for more than enough segments for a typical file.
// This is just for efficiency--it's OK if we wind up needing more.
// We expect two unattached Output_data objects: the file header and
// the segment headers.
this->special_output_list_.reserve(2);
+
+ // Initialize structure needed for an incremental build.
+ if (parameters->incremental())
+ this->incremental_inputs_ = new Incremental_inputs;
+
+ // The section name pool is worth optimizing in all cases, because
+ // it is small, but there are often overlaps due to .rel sections.
+ this->namepool_.set_optimize();
}
-// Hash a key we use to look up an output section mapping.
+// For incremental links, record the base file to be modified.
-size_t
-Layout::Hash_key::operator()(const Layout::Key& k) const
+void
+Layout::set_incremental_base(Incremental_binary* base)
{
- return k.first + k.second.first + k.second.second;
+ this->incremental_base_ = base;
+ this->free_list_.init(base->output_file()->filesize(), true);
}
-// Return whether PREFIX is a prefix of STR.
+// Hash a key we use to look up an output section mapping.
-static inline bool
-is_prefix_of(const char* prefix, const char* str)
+size_t
+Layout::Hash_key::operator()(const Layout::Key& k) const
{
- return strncmp(prefix, str, strlen(prefix)) == 0;
+ return k.first + k.second.first + k.second.second;
}
// Returns whether the given section is in the list of
// ".debug_aranges", // not used by gdb as of 6.7.1
".debug_frame",
".debug_info",
+ ".debug_types",
".debug_line",
".debug_loc",
".debug_macinfo",
// ".debug_aranges", // not used by gdb as of 6.7.1
// ".debug_frame",
".debug_info",
+ // ".debug_types",
".debug_line",
// ".debug_loc",
// ".debug_macinfo",
return false;
}
+// Sometimes we compress sections. This is typically done for
+// sections that are not part of normal program execution (such as
+// .debug_* sections), and where the readers of these sections know
+// how to deal with compressed sections. This routine doesn't say for
+// certain whether we'll compress -- it depends on commandline options
+// as well -- just whether this section is a candidate for compression.
+// (The Output_compressed_section class decides whether to compress
+// a given section, and picks the name of the compressed section.)
+
+static bool
+is_compressible_debug_section(const char* secname)
+{
+ return (is_prefix_of(".debug", secname));
+}
+
+// We may see compressed debug sections in input files. Return TRUE
+// if this is the name of a compressed debug section.
+
+bool
+is_compressed_debug_section(const char* secname)
+{
+ return (is_prefix_of(".zdebug", secname));
+}
+
// Whether to include this section in the link.
template<int size, bool big_endian>
if (is_prefix_of(".gnu.lto_", name))
return false;
}
+ // The GNU linker strips .gnu_debuglink sections, so we do too.
+ // This is a feature used to keep debugging information in
+ // separate files.
+ if (strcmp(name, ".gnu_debuglink") == 0)
+ return false;
return true;
default:
// Return the output section to use for section NAME with type TYPE
// and section flags FLAGS. NAME must be canonicalized in the string
-// pool, and NAME_KEY is the key.
+// pool, and NAME_KEY is the key. IS_INTERP is true if this is the
+// .interp section. IS_DYNAMIC_LINKER_SECTION is true if this section
+// is used by the dynamic linker. IS_RELRO is true for a relro
+// section. IS_LAST_RELRO is true for the last relro section.
+// IS_FIRST_NON_RELRO is true for the first non-relro section.
Output_section*
Layout::get_output_section(const char* name, Stringpool::Key name_key,
- elfcpp::Elf_Word type, elfcpp::Elf_Xword flags)
+ elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
+ Output_section_order order, bool is_relro)
{
elfcpp::Elf_Xword lookup_flags = flags;
}
if (os == NULL)
- os = this->make_output_section(name, type, flags);
+ os = this->make_output_section(name, type, flags, order, is_relro);
+
ins.first->second = os;
return os;
}
// RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
// linker created section. IS_INPUT_SECTION is true if we are
// choosing an output section for an input section found in a input
-// file. This will return NULL if the input section should be
-// discarded.
+// file. IS_INTERP is true if this is the .interp section.
+// IS_DYNAMIC_LINKER_SECTION is true if this section is used by the
+// dynamic linker. IS_RELRO is true for a relro section.
+// IS_LAST_RELRO is true for the last relro section.
+// IS_FIRST_NON_RELRO is true for the first non-relro section. This
+// will return NULL if the input section should be discarded.
Output_section*
Layout::choose_output_section(const Relobj* relobj, const char* name,
elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
- bool is_input_section)
+ bool is_input_section, Output_section_order order,
+ bool is_relro)
{
// We should not see any input sections after we have attached
// sections to segments.
// Some flags in the input section should not be automatically
// copied to the output section.
flags &= ~ (elfcpp::SHF_INFO_LINK
- | elfcpp::SHF_LINK_ORDER
| elfcpp::SHF_GROUP
| elfcpp::SHF_MERGE
| elfcpp::SHF_STRINGS);
+ // We only clear the SHF_LINK_ORDER flag in for
+ // a non-relocatable link.
+ if (!parameters->options().relocatable())
+ flags &= ~elfcpp::SHF_LINK_ORDER;
+
if (this->script_options_->saw_sections_clause())
{
// We are using a SECTIONS clause, so the output section is
Script_sections* ss = this->script_options_->script_sections();
const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
Output_section** output_section_slot;
- name = ss->output_section_name(file_name, name, &output_section_slot);
+ Script_sections::Section_type script_section_type;
+ const char* orig_name = name;
+ name = ss->output_section_name(file_name, name, &output_section_slot,
+ &script_section_type);
if (name == NULL)
{
+ gold_debug(DEBUG_SCRIPT, _("Unable to create output section '%s' "
+ "because it is not allowed by the "
+ "SECTIONS clause of the linker script"),
+ orig_name);
// The SECTIONS clause says to discard this input section.
return NULL;
}
+ // We can only handle script section types ST_NONE and ST_NOLOAD.
+ switch (script_section_type)
+ {
+ case Script_sections::ST_NONE:
+ break;
+ case Script_sections::ST_NOLOAD:
+ flags &= elfcpp::SHF_ALLOC;
+ break;
+ default:
+ gold_unreachable();
+ }
+
// If this is an orphan section--one not mentioned in the linker
// script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
// default processing below.
if (output_section_slot != NULL)
{
if (*output_section_slot != NULL)
- return *output_section_slot;
+ {
+ (*output_section_slot)->update_flags_for_input_section(flags);
+ return *output_section_slot;
+ }
// We don't put sections found in the linker script into
// SECTION_NAME_MAP_. That keeps us from getting confused
name = this->namepool_.add(name, false, NULL);
- Output_section* os = this->make_output_section(name, type, flags);
+ Output_section* os = this->make_output_section(name, type, flags,
+ order, is_relro);
+
os->set_found_in_sections_clause();
+
+ // Special handling for NOLOAD sections.
+ if (script_section_type == Script_sections::ST_NOLOAD)
+ {
+ os->set_is_noload();
+
+ // The constructor of Output_section sets addresses of non-ALLOC
+ // sections to 0 by default. We don't want that for NOLOAD
+ // sections even if they have no SHF_ALLOC flag.
+ if ((os->flags() & elfcpp::SHF_ALLOC) == 0
+ && os->is_address_valid())
+ {
+ gold_assert(os->address() == 0
+ && !os->is_offset_valid()
+ && !os->is_data_size_valid());
+ os->reset_address_and_file_offset();
+ }
+ }
+
*output_section_slot = os;
return os;
}
// FIXME: Handle SHF_OS_NONCONFORMING somewhere.
+ size_t len = strlen(name);
+ char* uncompressed_name = NULL;
+
+ // Compressed debug sections should be mapped to the corresponding
+ // uncompressed section.
+ if (is_compressed_debug_section(name))
+ {
+ uncompressed_name = new char[len];
+ uncompressed_name[0] = '.';
+ gold_assert(name[0] == '.' && name[1] == 'z');
+ strncpy(&uncompressed_name[1], &name[2], len - 2);
+ uncompressed_name[len - 1] = '\0';
+ len -= 1;
+ name = uncompressed_name;
+ }
+
// Turn NAME from the name of the input section into the name of the
// output section.
-
- size_t len = strlen(name);
- if (is_input_section && !parameters->options().relocatable())
+ if (is_input_section
+ && !this->script_options_->saw_sections_clause()
+ && !parameters->options().relocatable())
name = Layout::output_section_name(name, &len);
Stringpool::Key name_key;
name = this->namepool_.add_with_length(name, len, true, &name_key);
+ if (uncompressed_name != NULL)
+ delete[] uncompressed_name;
+
// Find or make the output section. The output section is selected
// based on the section name, type, and flags.
- return this->get_output_section(name, name_key, type, flags);
+ return this->get_output_section(name, name_key, type, flags, order, is_relro);
+}
+
+// For incremental links, record the initial fixed layout of a section
+// from the base file, and return a pointer to the Output_section.
+
+template<int size, bool big_endian>
+Output_section*
+Layout::init_fixed_output_section(const char* name,
+ elfcpp::Shdr<size, big_endian>& shdr)
+{
+ unsigned int sh_type = shdr.get_sh_type();
+
+ // We preserve the layout of PROGBITS, NOBITS, and NOTE sections.
+ // All others will be created from scratch and reallocated.
+ if (sh_type != elfcpp::SHT_PROGBITS
+ && sh_type != elfcpp::SHT_NOBITS
+ && sh_type != elfcpp::SHT_NOTE)
+ return NULL;
+
+ typename elfcpp::Elf_types<size>::Elf_Addr sh_addr = shdr.get_sh_addr();
+ typename elfcpp::Elf_types<size>::Elf_Off sh_offset = shdr.get_sh_offset();
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_size = shdr.get_sh_size();
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_addralign =
+ shdr.get_sh_addralign();
+
+ // Make the output section.
+ Stringpool::Key name_key;
+ name = this->namepool_.add(name, true, &name_key);
+ Output_section* os = this->get_output_section(name, name_key, sh_type,
+ sh_flags, ORDER_INVALID, false);
+ os->set_fixed_layout(sh_addr, sh_offset, sh_size, sh_addralign);
+ if (sh_type != elfcpp::SHT_NOBITS)
+ this->free_list_.remove(sh_offset, sh_offset + sh_size);
+ return os;
}
// Return the output section to use for input section SHNDX, with name
Output_section* os;
+ // Sometimes .init_array*, .preinit_array* and .fini_array* do not have
+ // correct section types. Force them here.
+ elfcpp::Elf_Word sh_type = shdr.get_sh_type();
+ if (sh_type == elfcpp::SHT_PROGBITS)
+ {
+ static const char init_array_prefix[] = ".init_array";
+ static const char preinit_array_prefix[] = ".preinit_array";
+ static const char fini_array_prefix[] = ".fini_array";
+ static size_t init_array_prefix_size = sizeof(init_array_prefix) - 1;
+ static size_t preinit_array_prefix_size =
+ sizeof(preinit_array_prefix) - 1;
+ static size_t fini_array_prefix_size = sizeof(fini_array_prefix) - 1;
+
+ if (strncmp(name, init_array_prefix, init_array_prefix_size) == 0)
+ sh_type = elfcpp::SHT_INIT_ARRAY;
+ else if (strncmp(name, preinit_array_prefix, preinit_array_prefix_size)
+ == 0)
+ sh_type = elfcpp::SHT_PREINIT_ARRAY;
+ else if (strncmp(name, fini_array_prefix, fini_array_prefix_size) == 0)
+ sh_type = elfcpp::SHT_FINI_ARRAY;
+ }
+
// In a relocatable link a grouped section must not be combined with
// any other sections.
if (parameters->options().relocatable()
&& (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
{
name = this->namepool_.add(name, true, NULL);
- os = this->make_output_section(name, shdr.get_sh_type(),
- shdr.get_sh_flags());
+ os = this->make_output_section(name, sh_type, shdr.get_sh_flags(),
+ ORDER_INVALID, false);
}
else
{
- os = this->choose_output_section(object, name, shdr.get_sh_type(),
- shdr.get_sh_flags(), true);
+ os = this->choose_output_section(object, name, sh_type,
+ shdr.get_sh_flags(), true,
+ ORDER_INVALID, false);
if (os == NULL)
return NULL;
}
// FIXME: Handle SHF_LINK_ORDER somewhere.
- *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
+ *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
this->script_options_->saw_sections_clause());
+ this->have_added_input_section_ = true;
return os;
}
gold_unreachable();
name += data_section->name();
- Output_section* os = this->choose_output_section(object, name.c_str(),
- sh_type,
- shdr.get_sh_flags(),
- false);
+ // In a relocatable link relocs for a grouped section must not be
+ // combined with other reloc sections.
+ Output_section* os;
+ if (!parameters->options().relocatable()
+ || (data_section->flags() & elfcpp::SHF_GROUP) == 0)
+ os = this->choose_output_section(object, name.c_str(), sh_type,
+ shdr.get_sh_flags(), false,
+ ORDER_INVALID, false);
+ else
+ {
+ const char* n = this->namepool_.add(name.c_str(), true, NULL);
+ os = this->make_output_section(n, sh_type, shdr.get_sh_flags(),
+ ORDER_INVALID, false);
+ }
os->set_should_link_to_symtab();
os->set_info_section(data_section);
group_section_name = this->namepool_.add(group_section_name, true, NULL);
Output_section* os = this->make_output_section(group_section_name,
elfcpp::SHT_GROUP,
- shdr.get_sh_flags());
+ shdr.get_sh_flags(),
+ ORDER_INVALID, false);
// We need to find a symbol with the signature in the symbol table.
// If we don't find one now, we need to look again later.
os->set_info_symndx(sym);
else
{
+ // Reserve some space to minimize reallocations.
+ if (this->group_signatures_.empty())
+ this->group_signatures_.reserve(this->number_of_input_files_ * 16);
+
// We will wind up using a symbol whose name is the signature.
// So just put the signature in the symbol name pool to save it.
signature = symtab->canonicalize_name(signature);
gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
const char* const name = ".eh_frame";
- Output_section* os = this->choose_output_section(object,
- name,
+ Output_section* os = this->choose_output_section(object, name,
elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC,
- false);
+ elfcpp::SHF_ALLOC, false,
+ ORDER_EHFRAME, false);
if (os == NULL)
return NULL;
this->eh_frame_section_ = os;
this->eh_frame_data_ = new Eh_frame();
- if (this->options_.eh_frame_hdr())
+ // For incremental linking, we do not optimize .eh_frame sections
+ // or create a .eh_frame_hdr section.
+ if (parameters->options().eh_frame_hdr() && !parameters->incremental())
{
Output_section* hdr_os =
- this->choose_output_section(NULL,
- ".eh_frame_hdr",
+ this->choose_output_section(NULL, ".eh_frame_hdr",
elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC,
- false);
+ elfcpp::SHF_ALLOC, false,
+ ORDER_EHFRAME, false);
if (hdr_os != NULL)
{
Output_segment* hdr_oseg;
hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
elfcpp::PF_R);
- hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R);
+ hdr_oseg->add_output_section_to_nonload(hdr_os,
+ elfcpp::PF_R);
}
this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
gold_assert(this->eh_frame_section_ == os);
- if (this->eh_frame_data_->add_ehframe_input_section(object,
- symbols,
- symbols_size,
- symbol_names,
- symbol_names_size,
- shndx,
- reloc_shndx,
- reloc_type))
+ if (!parameters->incremental()
+ && this->eh_frame_data_->add_ehframe_input_section(object,
+ symbols,
+ symbols_size,
+ symbol_names,
+ symbol_names_size,
+ shndx,
+ reloc_shndx,
+ reloc_type))
{
os->update_flags_for_input_section(shdr.get_sh_flags());
+ // A writable .eh_frame section is a RELRO section.
+ if ((shdr.get_sh_flags() & elfcpp::SHF_WRITE) != 0)
+ os->set_is_relro();
+
// We found a .eh_frame section we are going to optimize, so now
// we can add the set of optimized sections to the output
// section. We need to postpone adding this until we've found a
// We couldn't handle this .eh_frame section for some reason.
// Add it as a normal section.
bool saw_sections_clause = this->script_options_->saw_sections_clause();
- *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
+ *off = os->add_input_section(this, object, shndx, name, shdr, reloc_shndx,
saw_sections_clause);
+ this->have_added_input_section_ = true;
}
return os;
Output_section*
Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags,
- Output_section_data* posd)
+ Output_section_data* posd,
+ Output_section_order order, bool is_relro)
{
Output_section* os = this->choose_output_section(NULL, name, type, flags,
- false);
+ false, order, is_relro);
if (os != NULL)
os->add_output_section_data(posd);
return os;
return ret;
}
-// Sometimes we compress sections. This is typically done for
-// sections that are not part of normal program execution (such as
-// .debug_* sections), and where the readers of these sections know
-// how to deal with compressed sections. (To make it easier for them,
-// we will rename the ouput section in such cases from .foo to
-// .foo.zlib.nnnn, where nnnn is the uncompressed size.) This routine
-// doesn't say for certain whether we'll compress -- it depends on
-// commandline options as well -- just whether this section is a
-// candidate for compression.
-
-static bool
-is_compressible_debug_section(const char* secname)
-{
- return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
-}
-
// Make a new Output_section, and attach it to segments as
-// appropriate.
+// appropriate. ORDER is the order in which this section should
+// appear in the output segment. IS_RELRO is true if this is a relro
+// (read-only after relocations) section.
Output_section*
Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
- elfcpp::Elf_Xword flags)
+ elfcpp::Elf_Xword flags,
+ Output_section_order order, bool is_relro)
{
Output_section* os;
if ((flags & elfcpp::SHF_ALLOC) == 0
- && strcmp(this->options_.compress_debug_sections(), "none") != 0
+ && strcmp(parameters->options().compress_debug_sections(), "none") != 0
&& is_compressible_debug_section(name))
- os = new Output_compressed_section(&this->options_, name, type, flags);
-
+ os = new Output_compressed_section(¶meters->options(), name, type,
+ flags);
else if ((flags & elfcpp::SHF_ALLOC) == 0
- && this->options_.strip_debug_non_line()
+ && parameters->options().strip_debug_non_line()
&& strcmp(".debug_abbrev", name) == 0)
{
os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
this->debug_info_->set_abbreviations(this->debug_abbrev_);
}
else if ((flags & elfcpp::SHF_ALLOC) == 0
- && this->options_.strip_debug_non_line()
+ && parameters->options().strip_debug_non_line()
&& strcmp(".debug_info", name) == 0)
{
os = this->debug_info_ = new Output_reduced_debug_info_section(
if (this->debug_abbrev_)
this->debug_info_->set_abbreviations(this->debug_abbrev_);
}
- else
- os = new Output_section(name, type, flags);
-
- this->section_list_.push_back(os);
-
- // The GNU linker by default sorts some sections by priority, so we
- // do the same. We need to know that this might happen before we
- // attach any input sections.
- if (!this->script_options_->saw_sections_clause()
- && (strcmp(name, ".ctors") == 0
- || strcmp(name, ".dtors") == 0
- || strcmp(name, ".init_array") == 0
- || strcmp(name, ".fini_array") == 0))
- os->set_may_sort_attached_input_sections();
+ else
+ {
+ // FIXME: const_cast is ugly.
+ Target* target = const_cast<Target*>(¶meters->target());
+ os = target->make_output_section(name, type, flags);
+ }
// With -z relro, we have to recognize the special sections by name.
// There is no other way.
+ bool is_relro_local = false;
if (!this->script_options_->saw_sections_clause()
&& parameters->options().relro()
&& type == elfcpp::SHT_PROGBITS
&& (flags & elfcpp::SHF_WRITE) != 0)
{
if (strcmp(name, ".data.rel.ro") == 0)
- os->set_is_relro();
+ is_relro = true;
else if (strcmp(name, ".data.rel.ro.local") == 0)
{
- os->set_is_relro();
- os->set_is_relro_local();
+ is_relro = true;
+ is_relro_local = true;
}
+ else if (type == elfcpp::SHT_INIT_ARRAY
+ || type == elfcpp::SHT_FINI_ARRAY
+ || type == elfcpp::SHT_PREINIT_ARRAY)
+ is_relro = true;
+ else if (strcmp(name, ".ctors") == 0
+ || strcmp(name, ".dtors") == 0
+ || strcmp(name, ".jcr") == 0)
+ is_relro = true;
}
+ if (is_relro)
+ os->set_is_relro();
+
+ if (order == ORDER_INVALID && (flags & elfcpp::SHF_ALLOC) != 0)
+ order = this->default_section_order(os, is_relro_local);
+
+ os->set_order(order);
+
+ parameters->target().new_output_section(os);
+
+ this->section_list_.push_back(os);
+
+ // The GNU linker by default sorts some sections by priority, so we
+ // do the same. We need to know that this might happen before we
+ // attach any input sections.
+ if (!this->script_options_->saw_sections_clause()
+ && (strcmp(name, ".ctors") == 0
+ || strcmp(name, ".dtors") == 0
+ || strcmp(name, ".init_array") == 0
+ || strcmp(name, ".fini_array") == 0))
+ os->set_may_sort_attached_input_sections();
+
+ // Check for .stab*str sections, as .stab* sections need to link to
+ // them.
+ if (type == elfcpp::SHT_STRTAB
+ && !this->have_stabstr_section_
+ && strncmp(name, ".stab", 5) == 0
+ && strcmp(name + strlen(name) - 3, "str") == 0)
+ this->have_stabstr_section_ = true;
+
// If we have already attached the sections to segments, then we
// need to attach this one now. This happens for sections created
// directly by the linker.
return os;
}
+// Return the default order in which a section should be placed in an
+// output segment. This function captures a lot of the ideas in
+// ld/scripttempl/elf.sc in the GNU linker. Note that the order of a
+// linker created section is normally set when the section is created;
+// this function is used for input sections.
+
+Output_section_order
+Layout::default_section_order(Output_section* os, bool is_relro_local)
+{
+ gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
+ bool is_write = (os->flags() & elfcpp::SHF_WRITE) != 0;
+ bool is_execinstr = (os->flags() & elfcpp::SHF_EXECINSTR) != 0;
+ bool is_bss = false;
+
+ switch (os->type())
+ {
+ default:
+ case elfcpp::SHT_PROGBITS:
+ break;
+ case elfcpp::SHT_NOBITS:
+ is_bss = true;
+ break;
+ case elfcpp::SHT_RELA:
+ case elfcpp::SHT_REL:
+ if (!is_write)
+ return ORDER_DYNAMIC_RELOCS;
+ break;
+ case elfcpp::SHT_HASH:
+ case elfcpp::SHT_DYNAMIC:
+ case elfcpp::SHT_SHLIB:
+ case elfcpp::SHT_DYNSYM:
+ case elfcpp::SHT_GNU_HASH:
+ case elfcpp::SHT_GNU_verdef:
+ case elfcpp::SHT_GNU_verneed:
+ case elfcpp::SHT_GNU_versym:
+ if (!is_write)
+ return ORDER_DYNAMIC_LINKER;
+ break;
+ case elfcpp::SHT_NOTE:
+ return is_write ? ORDER_RW_NOTE : ORDER_RO_NOTE;
+ }
+
+ if ((os->flags() & elfcpp::SHF_TLS) != 0)
+ return is_bss ? ORDER_TLS_BSS : ORDER_TLS_DATA;
+
+ if (!is_bss && !is_write)
+ {
+ if (is_execinstr)
+ {
+ if (strcmp(os->name(), ".init") == 0)
+ return ORDER_INIT;
+ else if (strcmp(os->name(), ".fini") == 0)
+ return ORDER_FINI;
+ }
+ return is_execinstr ? ORDER_TEXT : ORDER_READONLY;
+ }
+
+ if (os->is_relro())
+ return is_relro_local ? ORDER_RELRO_LOCAL : ORDER_RELRO;
+
+ if (os->is_small_section())
+ return is_bss ? ORDER_SMALL_BSS : ORDER_SMALL_DATA;
+ if (os->is_large_section())
+ return is_bss ? ORDER_LARGE_BSS : ORDER_LARGE_DATA;
+
+ return is_bss ? ORDER_BSS : ORDER_DATA;
+}
+
// Attach output sections to segments. This is called after we have
// seen all the input sections.
elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
+ // Check for --section-start.
+ uint64_t addr;
+ bool is_address_set = parameters->options().section_start(os->name(), &addr);
+
// In general the only thing we really care about for PT_LOAD
- // segments is whether or not they are writable, so that is how we
- // search for them. People who need segments sorted on some other
- // basis will have to use a linker script.
+ // segments is whether or not they are writable or executable,
+ // so that is how we search for them.
+ // Large data sections also go into their own PT_LOAD segment.
+ // People who need segments sorted on some other basis will
+ // have to use a linker script.
Segment_list::const_iterator p;
for (p = this->segment_list_.begin();
p != this->segment_list_.end();
++p)
{
- if ((*p)->type() == elfcpp::PT_LOAD
- && (parameters->options().omagic()
- || ((*p)->flags() & elfcpp::PF_W) == (seg_flags & elfcpp::PF_W)))
- {
- // If -Tbss was specified, we need to separate the data
- // and BSS segments.
- if (this->options_.user_set_Tbss())
- {
- if ((os->type() == elfcpp::SHT_NOBITS)
- == (*p)->has_any_data_sections())
- continue;
- }
+ if ((*p)->type() != elfcpp::PT_LOAD)
+ continue;
+ if (!parameters->options().omagic()
+ && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
+ continue;
+ if (parameters->options().rosegment()
+ && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X))
+ continue;
+ // If -Tbss was specified, we need to separate the data and BSS
+ // segments.
+ if (parameters->options().user_set_Tbss())
+ {
+ if ((os->type() == elfcpp::SHT_NOBITS)
+ == (*p)->has_any_data_sections())
+ continue;
+ }
+ if (os->is_large_data_section() && !(*p)->is_large_data_segment())
+ continue;
- (*p)->add_output_section(os, seg_flags);
- break;
- }
+ if (is_address_set)
+ {
+ if ((*p)->are_addresses_set())
+ continue;
+
+ (*p)->add_initial_output_data(os);
+ (*p)->update_flags_for_output_section(seg_flags);
+ (*p)->set_addresses(addr, addr);
+ break;
+ }
+
+ (*p)->add_output_section_to_load(this, os, seg_flags);
+ break;
}
if (p == this->segment_list_.end())
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
seg_flags);
- oseg->add_output_section(os, seg_flags);
+ if (os->is_large_data_section())
+ oseg->set_is_large_data_segment();
+ oseg->add_output_section_to_load(this, os, seg_flags);
+ if (is_address_set)
+ oseg->set_addresses(addr, addr);
}
// If we see a loadable SHT_NOTE section, we create a PT_NOTE
&& (((*p)->flags() & elfcpp::PF_W)
== (seg_flags & elfcpp::PF_W)))
{
- (*p)->add_output_section(os, seg_flags);
+ (*p)->add_output_section_to_nonload(os, seg_flags);
break;
}
}
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
seg_flags);
- oseg->add_output_section(os, seg_flags);
+ oseg->add_output_section_to_nonload(os, seg_flags);
}
}
{
if (this->tls_segment_ == NULL)
this->make_output_segment(elfcpp::PT_TLS, seg_flags);
- this->tls_segment_->add_output_section(os, seg_flags);
+ this->tls_segment_->add_output_section_to_nonload(os, seg_flags);
}
// If -z relro is in effect, and we see a relro section, we create a
gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
if (this->relro_segment_ == NULL)
this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
- this->relro_segment_->add_output_section(os, seg_flags);
+ this->relro_segment_->add_output_section_to_nonload(os, seg_flags);
}
}
// Make an output section for a script.
Output_section*
-Layout::make_output_section_for_script(const char* name)
+Layout::make_output_section_for_script(
+ const char* name,
+ Script_sections::Section_type section_type)
{
name = this->namepool_.add(name, false, NULL);
+ elfcpp::Elf_Xword sh_flags = elfcpp::SHF_ALLOC;
+ if (section_type == Script_sections::ST_NOLOAD)
+ sh_flags = 0;
Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC);
+ sh_flags, ORDER_INVALID,
+ false);
os->set_found_in_sections_clause();
+ if (section_type == Script_sections::ST_NOLOAD)
+ os->set_is_noload();
return os;
}
// object. On some targets that will force an executable stack.
void
-Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
+Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
+ const Object* obj)
{
if (!seen_gnu_stack)
- this->input_without_gnu_stack_note_ = true;
+ {
+ this->input_without_gnu_stack_note_ = true;
+ if (parameters->options().warn_execstack()
+ && parameters->target().is_default_stack_executable())
+ gold_warning(_("%s: missing .note.GNU-stack section"
+ " implies executable stack"),
+ obj->name().c_str());
+ }
else
{
this->input_with_gnu_stack_note_ = true;
if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
- this->input_requires_executable_stack_ = true;
+ {
+ this->input_requires_executable_stack_ = true;
+ if (parameters->options().warn_execstack()
+ || parameters->options().is_stack_executable())
+ gold_warning(_("%s: requires executable stack"),
+ obj->name().c_str());
+ }
}
}
+// Create automatic note sections.
+
+void
+Layout::create_notes()
+{
+ this->create_gold_note();
+ this->create_executable_stack_info();
+ this->create_build_id();
+}
+
// Create the dynamic sections which are needed before we read the
// relocs.
elfcpp::SHT_DYNAMIC,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
- false);
- this->dynamic_section_->set_is_relro();
+ false, ORDER_RELRO,
+ true);
- symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
- elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
- elfcpp::STV_HIDDEN, 0, false, false);
+ this->dynamic_symbol_ =
+ symtab->define_in_output_data("_DYNAMIC", NULL, Symbol_table::PREDEFINED,
+ this->dynamic_section_, 0, 0,
+ elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
+ elfcpp::STV_HIDDEN, 0, false, false);
this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_);
++p)
{
const char* const name = (*p)->name();
- if (name[strspn(name,
- ("0123456789"
- "ABCDEFGHIJKLMNOPWRSTUVWXYZ"
- "abcdefghijklmnopqrstuvwxyz"
- "_"))]
- == '\0')
+ if (is_cident(name))
{
const std::string name_string(name);
- const std::string start_name("__start_" + name_string);
- const std::string stop_name("__stop_" + name_string);
+ const std::string start_name(cident_section_start_prefix
+ + name_string);
+ const std::string stop_name(cident_section_stop_prefix
+ + name_string);
symtab->define_in_output_data(start_name.c_str(),
NULL, // version
+ Symbol_table::PREDEFINED,
*p,
0, // value
0, // symsize
symtab->define_in_output_data(stop_name.c_str(),
NULL, // version
+ Symbol_table::PREDEFINED,
*p,
0, // value
0, // symsize
Output_segment*
Layout::find_first_load_seg()
{
+ Output_segment* best = NULL;
for (Segment_list::const_iterator p = this->segment_list_.begin();
p != this->segment_list_.end();
++p)
&& ((*p)->flags() & elfcpp::PF_R) != 0
&& (parameters->options().omagic()
|| ((*p)->flags() & elfcpp::PF_W) == 0))
- return *p;
+ {
+ if (best == NULL || this->segment_precedes(*p, best))
+ best = *p;
+ }
}
+ if (best != NULL)
+ return best;
gold_assert(!this->script_options_->saw_phdrs_clause());
return load_seg;
}
+// Save states of all current output segments. Store saved states
+// in SEGMENT_STATES.
+
+void
+Layout::save_segments(Segment_states* segment_states)
+{
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ Output_segment* segment = *p;
+ // Shallow copy.
+ Output_segment* copy = new Output_segment(*segment);
+ (*segment_states)[segment] = copy;
+ }
+}
+
+// Restore states of output segments and delete any segment not found in
+// SEGMENT_STATES.
+
+void
+Layout::restore_segments(const Segment_states* segment_states)
+{
+ // Go through the segment list and remove any segment added in the
+ // relaxation loop.
+ this->tls_segment_ = NULL;
+ this->relro_segment_ = NULL;
+ Segment_list::iterator list_iter = this->segment_list_.begin();
+ while (list_iter != this->segment_list_.end())
+ {
+ Output_segment* segment = *list_iter;
+ Segment_states::const_iterator states_iter =
+ segment_states->find(segment);
+ if (states_iter != segment_states->end())
+ {
+ const Output_segment* copy = states_iter->second;
+ // Shallow copy to restore states.
+ *segment = *copy;
+
+ // Also fix up TLS and RELRO segment pointers as appropriate.
+ if (segment->type() == elfcpp::PT_TLS)
+ this->tls_segment_ = segment;
+ else if (segment->type() == elfcpp::PT_GNU_RELRO)
+ this->relro_segment_ = segment;
+
+ ++list_iter;
+ }
+ else
+ {
+ list_iter = this->segment_list_.erase(list_iter);
+ // This is a segment created during section layout. It should be
+ // safe to remove it since we should have removed all pointers to it.
+ delete segment;
+ }
+ }
+}
+
+// Clean up after relaxation so that sections can be laid out again.
+
+void
+Layout::clean_up_after_relaxation()
+{
+ // Restore the segments to point state just prior to the relaxation loop.
+ Script_sections* script_section = this->script_options_->script_sections();
+ script_section->release_segments();
+ this->restore_segments(this->segment_states_);
+
+ // Reset section addresses and file offsets
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ (*p)->restore_states();
+
+ // If an input section changes size because of relaxation,
+ // we need to adjust the section offsets of all input sections.
+ // after such a section.
+ if ((*p)->section_offsets_need_adjustment())
+ (*p)->adjust_section_offsets();
+
+ (*p)->reset_address_and_file_offset();
+ }
+
+ // Reset special output object address and file offsets.
+ for (Data_list::iterator p = this->special_output_list_.begin();
+ p != this->special_output_list_.end();
+ ++p)
+ (*p)->reset_address_and_file_offset();
+
+ // A linker script may have created some output section data objects.
+ // They are useless now.
+ for (Output_section_data_list::const_iterator p =
+ this->script_output_section_data_list_.begin();
+ p != this->script_output_section_data_list_.end();
+ ++p)
+ delete *p;
+ this->script_output_section_data_list_.clear();
+}
+
+// Prepare for relaxation.
+
+void
+Layout::prepare_for_relaxation()
+{
+ // Create an relaxation debug check if in debugging mode.
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ this->relaxation_debug_check_ = new Relaxation_debug_check();
+
+ // Save segment states.
+ this->segment_states_ = new Segment_states();
+ this->save_segments(this->segment_states_);
+
+ for(Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ (*p)->save_states();
+
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ this->relaxation_debug_check_->check_output_data_for_reset_values(
+ this->section_list_, this->special_output_list_);
+
+ // Also enable recording of output section data from scripts.
+ this->record_output_section_data_from_script_ = true;
+}
+
+// Relaxation loop body: If target has no relaxation, this runs only once
+// Otherwise, the target relaxation hook is called at the end of
+// each iteration. If the hook returns true, it means re-layout of
+// section is required.
+//
+// The number of segments created by a linking script without a PHDRS
+// clause may be affected by section sizes and alignments. There is
+// a remote chance that relaxation causes different number of PT_LOAD
+// segments are created and sections are attached to different segments.
+// Therefore, we always throw away all segments created during section
+// layout. In order to be able to restart the section layout, we keep
+// a copy of the segment list right before the relaxation loop and use
+// that to restore the segments.
+//
+// PASS is the current relaxation pass number.
+// SYMTAB is a symbol table.
+// PLOAD_SEG is the address of a pointer for the load segment.
+// PHDR_SEG is a pointer to the PHDR segment.
+// SEGMENT_HEADERS points to the output segment header.
+// FILE_HEADER points to the output file header.
+// PSHNDX is the address to store the output section index.
+
+off_t inline
+Layout::relaxation_loop_body(
+ int pass,
+ Target* target,
+ Symbol_table* symtab,
+ Output_segment** pload_seg,
+ Output_segment* phdr_seg,
+ Output_segment_headers* segment_headers,
+ Output_file_header* file_header,
+ unsigned int* pshndx)
+{
+ // If this is not the first iteration, we need to clean up after
+ // relaxation so that we can lay out the sections again.
+ if (pass != 0)
+ this->clean_up_after_relaxation();
+
+ // If there is a SECTIONS clause, put all the input sections into
+ // the required order.
+ Output_segment* load_seg;
+ if (this->script_options_->saw_sections_clause())
+ load_seg = this->set_section_addresses_from_script(symtab);
+ else if (parameters->options().relocatable())
+ load_seg = NULL;
+ else
+ load_seg = this->find_first_load_seg();
+
+ if (parameters->options().oformat_enum()
+ != General_options::OBJECT_FORMAT_ELF)
+ load_seg = NULL;
+
+ // If the user set the address of the text segment, that may not be
+ // compatible with putting the segment headers and file headers into
+ // that segment.
+ if (parameters->options().user_set_Ttext())
+ load_seg = NULL;
+
+ gold_assert(phdr_seg == NULL
+ || load_seg != NULL
+ || this->script_options_->saw_sections_clause());
+
+ // If the address of the load segment we found has been set by
+ // --section-start rather than by a script, then adjust the VMA and
+ // LMA downward if possible to include the file and section headers.
+ uint64_t header_gap = 0;
+ if (load_seg != NULL
+ && load_seg->are_addresses_set()
+ && !this->script_options_->saw_sections_clause()
+ && !parameters->options().relocatable())
+ {
+ file_header->finalize_data_size();
+ segment_headers->finalize_data_size();
+ size_t sizeof_headers = (file_header->data_size()
+ + segment_headers->data_size());
+ const uint64_t abi_pagesize = target->abi_pagesize();
+ uint64_t hdr_paddr = load_seg->paddr() - sizeof_headers;
+ hdr_paddr &= ~(abi_pagesize - 1);
+ uint64_t subtract = load_seg->paddr() - hdr_paddr;
+ if (load_seg->paddr() < subtract || load_seg->vaddr() < subtract)
+ load_seg = NULL;
+ else
+ {
+ load_seg->set_addresses(load_seg->vaddr() - subtract,
+ load_seg->paddr() - subtract);
+ header_gap = subtract - sizeof_headers;
+ }
+ }
+
+ // Lay out the segment headers.
+ if (!parameters->options().relocatable())
+ {
+ gold_assert(segment_headers != NULL);
+ if (header_gap != 0 && load_seg != NULL)
+ {
+ Output_data_zero_fill* z = new Output_data_zero_fill(header_gap, 1);
+ load_seg->add_initial_output_data(z);
+ }
+ if (load_seg != NULL)
+ load_seg->add_initial_output_data(segment_headers);
+ if (phdr_seg != NULL)
+ phdr_seg->add_initial_output_data(segment_headers);
+ }
+
+ // Lay out the file header.
+ if (load_seg != NULL)
+ load_seg->add_initial_output_data(file_header);
+
+ if (this->script_options_->saw_phdrs_clause()
+ && !parameters->options().relocatable())
+ {
+ // Support use of FILEHDRS and PHDRS attachments in a PHDRS
+ // clause in a linker script.
+ Script_sections* ss = this->script_options_->script_sections();
+ ss->put_headers_in_phdrs(file_header, segment_headers);
+ }
+
+ // We set the output section indexes in set_segment_offsets and
+ // set_section_indexes.
+ *pshndx = 1;
+
+ // Set the file offsets of all the segments, and all the sections
+ // they contain.
+ off_t off;
+ if (!parameters->options().relocatable())
+ off = this->set_segment_offsets(target, load_seg, pshndx);
+ else
+ off = this->set_relocatable_section_offsets(file_header, pshndx);
+
+ // Verify that the dummy relaxation does not change anything.
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ {
+ if (pass == 0)
+ this->relaxation_debug_check_->read_sections(this->section_list_);
+ else
+ this->relaxation_debug_check_->verify_sections(this->section_list_);
+ }
+
+ *pload_seg = load_seg;
+ return off;
+}
+
+// Search the list of patterns and find the postion of the given section
+// name in the output section. If the section name matches a glob
+// pattern and a non-glob name, then the non-glob position takes
+// precedence. Return 0 if no match is found.
+
+unsigned int
+Layout::find_section_order_index(const std::string& section_name)
+{
+ Unordered_map<std::string, unsigned int>::iterator map_it;
+ map_it = this->input_section_position_.find(section_name);
+ if (map_it != this->input_section_position_.end())
+ return map_it->second;
+
+ // Absolute match failed. Linear search the glob patterns.
+ std::vector<std::string>::iterator it;
+ for (it = this->input_section_glob_.begin();
+ it != this->input_section_glob_.end();
+ ++it)
+ {
+ if (fnmatch((*it).c_str(), section_name.c_str(), FNM_NOESCAPE) == 0)
+ {
+ map_it = this->input_section_position_.find(*it);
+ gold_assert(map_it != this->input_section_position_.end());
+ return map_it->second;
+ }
+ }
+ return 0;
+}
+
+// Read the sequence of input sections from the file specified with
+// --section-ordering-file.
+
+void
+Layout::read_layout_from_file()
+{
+ const char* filename = parameters->options().section_ordering_file();
+ std::ifstream in;
+ std::string line;
+
+ in.open(filename);
+ if (!in)
+ gold_fatal(_("unable to open --section-ordering-file file %s: %s"),
+ filename, strerror(errno));
+
+ std::getline(in, line); // this chops off the trailing \n, if any
+ unsigned int position = 1;
+
+ while (in)
+ {
+ if (!line.empty() && line[line.length() - 1] == '\r') // Windows
+ line.resize(line.length() - 1);
+ // Ignore comments, beginning with '#'
+ if (line[0] == '#')
+ {
+ std::getline(in, line);
+ continue;
+ }
+ this->input_section_position_[line] = position;
+ // Store all glob patterns in a vector.
+ if (is_wildcard_string(line.c_str()))
+ this->input_section_glob_.push_back(line);
+ position++;
+ std::getline(in, line);
+ }
+}
+
// Finalize the layout. When this is called, we have created all the
// output sections and all the output segments which are based on
// input sections. We have several things to do, and we have to do
Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
Target* target, const Task* task)
{
- target->finalize_sections(this);
+ target->finalize_sections(this, input_objects, symtab);
this->count_local_symbols(task, input_objects);
- this->create_gold_note();
- this->create_executable_stack_info(target);
- this->create_build_id();
+ this->link_stabs_sections();
Output_segment* phdr_seg = NULL;
if (!parameters->options().relocatable() && !parameters->doing_static_link())
// it in a PT_DYNAMIC segment.
this->finish_dynamic_section(input_objects, symtab);
- // We should have added everything we need to the dynamic string
- // table.
- this->dynpool_.set_string_offsets();
-
- // Create the version sections. We can't do this until the
- // dynamic string table is complete.
- this->create_version_sections(&versions, symtab, local_dynamic_count,
- dynamic_symbols, dynstr);
- }
-
- // If there is a SECTIONS clause, put all the input sections into
- // the required order.
- Output_segment* load_seg;
- if (this->script_options_->saw_sections_clause())
- load_seg = this->set_section_addresses_from_script(symtab);
- else if (parameters->options().relocatable())
- load_seg = NULL;
- else
- load_seg = this->find_first_load_seg();
-
- if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
- load_seg = NULL;
+ // We should have added everything we need to the dynamic string
+ // table.
+ this->dynpool_.set_string_offsets();
- gold_assert(phdr_seg == NULL || load_seg != NULL);
+ // Create the version sections. We can't do this until the
+ // dynamic string table is complete.
+ this->create_version_sections(&versions, symtab, local_dynamic_count,
+ dynamic_symbols, dynstr);
- // Lay out the segment headers.
- Output_segment_headers* segment_headers;
- if (parameters->options().relocatable())
- segment_headers = NULL;
- else
- {
- segment_headers = new Output_segment_headers(this->segment_list_);
- if (load_seg != NULL)
- load_seg->add_initial_output_data(segment_headers);
- if (phdr_seg != NULL)
- phdr_seg->add_initial_output_data(segment_headers);
+ // Set the size of the _DYNAMIC symbol. We can't do this until
+ // after we call create_version_sections.
+ this->set_dynamic_symbol_size(symtab);
}
+
+ // Create segment headers.
+ Output_segment_headers* segment_headers =
+ (parameters->options().relocatable()
+ ? NULL
+ : new Output_segment_headers(this->segment_list_));
// Lay out the file header.
- Output_file_header* file_header;
- file_header = new Output_file_header(target, symtab, segment_headers,
- this->options_.entry());
- if (load_seg != NULL)
- load_seg->add_initial_output_data(file_header);
+ Output_file_header* file_header
+ = new Output_file_header(target, symtab, segment_headers,
+ parameters->options().entry());
this->special_output_list_.push_back(file_header);
if (segment_headers != NULL)
this->special_output_list_.push_back(segment_headers);
- if (this->script_options_->saw_phdrs_clause()
- && !parameters->options().relocatable())
+ // Find approriate places for orphan output sections if we are using
+ // a linker script.
+ if (this->script_options_->saw_sections_clause())
+ this->place_orphan_sections_in_script();
+
+ Output_segment* load_seg;
+ off_t off;
+ unsigned int shndx;
+ int pass = 0;
+
+ // Take a snapshot of the section layout as needed.
+ if (target->may_relax())
+ this->prepare_for_relaxation();
+
+ // Run the relaxation loop to lay out sections.
+ do
{
- // Support use of FILEHDRS and PHDRS attachments in a PHDRS
- // clause in a linker script.
- Script_sections* ss = this->script_options_->script_sections();
- ss->put_headers_in_phdrs(file_header, segment_headers);
+ off = this->relaxation_loop_body(pass, target, symtab, &load_seg,
+ phdr_seg, segment_headers, file_header,
+ &shndx);
+ pass++;
}
-
- // We set the output section indexes in set_segment_offsets and
- // set_section_indexes.
- unsigned int shndx = 1;
-
- // Set the file offsets of all the segments, and all the sections
- // they contain.
- off_t off;
- if (!parameters->options().relocatable())
- off = this->set_segment_offsets(target, load_seg, &shndx);
- else
- off = this->set_relocatable_section_offsets(file_header, &shndx);
+ while (target->may_relax()
+ && target->relax(pass, input_objects, symtab, this, task));
// Set the file offsets of all the non-data sections we've seen so
// far which don't have to wait for the input sections. We need
// be called after the symbol table has been finalized.
this->script_options_->finalize_symbols(symtab, this);
+ // Create the incremental inputs sections.
+ if (this->incremental_inputs_)
+ {
+ this->incremental_inputs_->finalize();
+ this->create_incremental_info_sections(symtab);
+ }
+
// Create the .shstrtab section.
Output_section* shstrtab_section = this->create_shstrtab();
// If there are no sections which require postprocessing, we can
// handle the section names now, and avoid a resize later.
if (!this->any_postprocessing_sections_)
- off = this->set_section_offsets(off,
+ {
+ off = this->set_section_offsets(off,
+ POSTPROCESSING_SECTIONS_PASS);
+ off =
+ this->set_section_offsets(off,
STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
+ }
file_header->set_section_info(this->section_headers_, shstrtab_section);
}
// Create a note header following the format defined in the ELF ABI.
-// NAME is the name, NOTE_TYPE is the type, DESCSZ is the size of the
-// descriptor. ALLOCATE is true if the section should be allocated in
-// memory. This returns the new note section. It sets
-// *TRAILING_PADDING to the number of trailing zero bytes required.
+// NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
+// of the section to create, DESCSZ is the size of the descriptor.
+// ALLOCATE is true if the section should be allocated in memory.
+// This returns the new note section. It sets *TRAILING_PADDING to
+// the number of trailing zero bytes required.
Output_section*
-Layout::create_note(const char* name, int note_type, size_t descsz,
+Layout::create_note(const char* name, int note_type,
+ const char* section_name, size_t descsz,
bool allocate, size_t* trailing_padding)
{
// Authorities all agree that the values in a .note field should
memcpy(buffer + 3 * (size / 8), name, namesz);
- const char* note_name = this->namepool_.add(".note", false, NULL);
elfcpp::Elf_Xword flags = 0;
+ Output_section_order order = ORDER_INVALID;
if (allocate)
- flags = elfcpp::SHF_ALLOC;
- Output_section* os = this->make_output_section(note_name,
- elfcpp::SHT_NOTE,
- flags);
+ {
+ flags = elfcpp::SHF_ALLOC;
+ order = ORDER_RO_NOTE;
+ }
+ Output_section* os = this->choose_output_section(NULL, section_name,
+ elfcpp::SHT_NOTE,
+ flags, false, order, false);
+ if (os == NULL)
+ return NULL;
+
Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
size / 8,
"** note header");
void
Layout::create_gold_note()
{
- if (parameters->options().relocatable())
+ if (parameters->options().relocatable()
+ || parameters->incremental_update())
return;
std::string desc = std::string("gold ") + gold::get_version_string();
size_t trailing_padding;
- Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
- desc.size(), false, &trailing_padding);
+ Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
+ ".note.gnu.gold-version", desc.size(),
+ false, &trailing_padding);
+ if (os == NULL)
+ return;
Output_section_data* posd = new Output_data_const(desc, 4);
os->add_output_section_data(posd);
// library, we create a PT_GNU_STACK segment.
void
-Layout::create_executable_stack_info(const Target* target)
+Layout::create_executable_stack_info()
{
bool is_stack_executable;
- if (this->options_.is_execstack_set())
- is_stack_executable = this->options_.is_stack_executable();
+ if (parameters->options().is_execstack_set())
+ is_stack_executable = parameters->options().is_stack_executable();
else if (!this->input_with_gnu_stack_note_)
return;
else
if (this->input_requires_executable_stack_)
is_stack_executable = true;
else if (this->input_without_gnu_stack_note_)
- is_stack_executable = target->is_default_stack_executable();
+ is_stack_executable =
+ parameters->target().is_default_stack_executable();
else
is_stack_executable = false;
}
elfcpp::Elf_Xword flags = 0;
if (is_stack_executable)
flags |= elfcpp::SHF_EXECINSTR;
- this->make_output_section(name, elfcpp::SHT_PROGBITS, flags);
+ this->make_output_section(name, elfcpp::SHT_PROGBITS, flags,
+ ORDER_INVALID, false);
}
else
{
// Create the note.
size_t trailing_padding;
Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
- descsz, true, &trailing_padding);
+ ".note.gnu.build-id", descsz, true,
+ &trailing_padding);
+ if (os == NULL)
+ return;
if (!desc.empty())
{
gold_assert(trailing_padding == 0);
this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
os->add_output_section_data(this->build_id_note_);
- os->set_after_input_sections();
}
}
+// If we have both .stabXX and .stabXXstr sections, then the sh_link
+// field of the former should point to the latter. I'm not sure who
+// started this, but the GNU linker does it, and some tools depend
+// upon it.
+
+void
+Layout::link_stabs_sections()
+{
+ if (!this->have_stabstr_section_)
+ return;
+
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if ((*p)->type() != elfcpp::SHT_STRTAB)
+ continue;
+
+ const char* name = (*p)->name();
+ if (strncmp(name, ".stab", 5) != 0)
+ continue;
+
+ size_t len = strlen(name);
+ if (strcmp(name + len - 3, "str") != 0)
+ continue;
+
+ std::string stab_name(name, len - 3);
+ Output_section* stab_sec;
+ stab_sec = this->find_output_section(stab_name.c_str());
+ if (stab_sec != NULL)
+ stab_sec->set_link_section(*p);
+ }
+}
+
+// Create .gnu_incremental_inputs and related sections needed
+// for the next run of incremental linking to check what has changed.
+
+void
+Layout::create_incremental_info_sections(Symbol_table* symtab)
+{
+ Incremental_inputs* incr = this->incremental_inputs_;
+
+ gold_assert(incr != NULL);
+
+ // Create the .gnu_incremental_inputs, _symtab, and _relocs input sections.
+ incr->create_data_sections(symtab);
+
+ // Add the .gnu_incremental_inputs section.
+ const char* incremental_inputs_name =
+ this->namepool_.add(".gnu_incremental_inputs", false, NULL);
+ Output_section* incremental_inputs_os =
+ this->make_output_section(incremental_inputs_name,
+ elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
+ ORDER_INVALID, false);
+ incremental_inputs_os->add_output_section_data(incr->inputs_section());
+
+ // Add the .gnu_incremental_symtab section.
+ const char* incremental_symtab_name =
+ this->namepool_.add(".gnu_incremental_symtab", false, NULL);
+ Output_section* incremental_symtab_os =
+ this->make_output_section(incremental_symtab_name,
+ elfcpp::SHT_GNU_INCREMENTAL_SYMTAB, 0,
+ ORDER_INVALID, false);
+ incremental_symtab_os->add_output_section_data(incr->symtab_section());
+ incremental_symtab_os->set_entsize(4);
+
+ // Add the .gnu_incremental_relocs section.
+ const char* incremental_relocs_name =
+ this->namepool_.add(".gnu_incremental_relocs", false, NULL);
+ Output_section* incremental_relocs_os =
+ this->make_output_section(incremental_relocs_name,
+ elfcpp::SHT_GNU_INCREMENTAL_RELOCS, 0,
+ ORDER_INVALID, false);
+ incremental_relocs_os->add_output_section_data(incr->relocs_section());
+ incremental_relocs_os->set_entsize(incr->relocs_entsize());
+
+ // Add the .gnu_incremental_got_plt section.
+ const char* incremental_got_plt_name =
+ this->namepool_.add(".gnu_incremental_got_plt", false, NULL);
+ Output_section* incremental_got_plt_os =
+ this->make_output_section(incremental_got_plt_name,
+ elfcpp::SHT_GNU_INCREMENTAL_GOT_PLT, 0,
+ ORDER_INVALID, false);
+ incremental_got_plt_os->add_output_section_data(incr->got_plt_section());
+
+ // Add the .gnu_incremental_strtab section.
+ const char* incremental_strtab_name =
+ this->namepool_.add(".gnu_incremental_strtab", false, NULL);
+ Output_section* incremental_strtab_os = this->make_output_section(incremental_strtab_name,
+ elfcpp::SHT_STRTAB, 0,
+ ORDER_INVALID, false);
+ Output_data_strtab* strtab_data =
+ new Output_data_strtab(incr->get_stringpool());
+ incremental_strtab_os->add_output_section_data(strtab_data);
+
+ incremental_inputs_os->set_after_input_sections();
+ incremental_symtab_os->set_after_input_sections();
+ incremental_relocs_os->set_after_input_sections();
+ incremental_got_plt_os->set_after_input_sections();
+
+ incremental_inputs_os->set_link_section(incremental_strtab_os);
+ incremental_symtab_os->set_link_section(incremental_inputs_os);
+ incremental_relocs_os->set_link_section(incremental_inputs_os);
+ incremental_got_plt_os->set_link_section(incremental_inputs_os);
+}
+
// Return whether SEG1 should be before SEG2 in the output file. This
// is based entirely on the segment type and flags. When this is
// called the segment addresses has normally not yet been set.
if (section_count1 > 0 && section_count2 == 0)
return false;
- uint64_t paddr1 = seg1->first_section_load_address();
- uint64_t paddr2 = seg2->first_section_load_address();
+ uint64_t paddr1 = (seg1->are_addresses_set()
+ ? seg1->paddr()
+ : seg1->first_section_load_address());
+ uint64_t paddr2 = (seg2->are_addresses_set()
+ ? seg2->paddr()
+ : seg2->first_section_load_address());
+
if (paddr1 != paddr2)
return paddr1 < paddr2;
}
else if (seg2->are_addresses_set())
return false;
- // We sort PT_LOAD segments based on the flags. Readonly segments
- // come before writable segments. Then writable segments with data
- // come before writable segments without data. Then executable
- // segments come before non-executable segments. Then the unlikely
- // case of a non-readable segment comes before the normal case of a
- // readable segment. If there are multiple segments with the same
- // type and flags, we require that the address be set, and we sort
- // by virtual address and then physical address.
+ // A segment which holds large data comes after a segment which does
+ // not hold large data.
+ if (seg1->is_large_data_segment())
+ {
+ if (!seg2->is_large_data_segment())
+ return false;
+ }
+ else if (seg2->is_large_data_segment())
+ return true;
+
+ // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
+ // segments come before writable segments. Then writable segments
+ // with data come before writable segments without data. Then
+ // executable segments come before non-executable segments. Then
+ // the unlikely case of a non-readable segment comes before the
+ // normal case of a readable segment. If there are multiple
+ // segments with the same type and flags, we require that the
+ // address be set, and we sort by virtual address and then physical
+ // address.
if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
return (flags1 & elfcpp::PF_W) == 0;
if ((flags1 & elfcpp::PF_W) != 0
gold_unreachable();
}
+// Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
+
+static off_t
+align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize)
+{
+ uint64_t unsigned_off = off;
+ uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
+ | (addr & (abi_pagesize - 1)));
+ if (aligned_off < unsigned_off)
+ aligned_off += abi_pagesize;
+ return aligned_off;
+}
+
// Set the file offsets of all the segments, and all the sections they
// contain. They have all been created. LOAD_SEG must be be laid out
// first. Return the offset of the data to follow.
off_t
Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
- unsigned int *pshndx)
+ unsigned int* pshndx)
{
// Sort them into the final order.
std::sort(this->segment_list_.begin(), this->segment_list_.end(),
// Find the PT_LOAD segments, and set their addresses and offsets
// and their section's addresses and offsets.
uint64_t addr;
- if (this->options_.user_set_Ttext())
- addr = this->options_.Ttext();
- else if (parameters->options().shared())
+ if (parameters->options().user_set_Ttext())
+ addr = parameters->options().Ttext();
+ else if (parameters->options().output_is_position_independent())
addr = 0;
else
addr = target->default_text_segment_address();
}
}
+ unsigned int increase_relro = this->increase_relro_;
+ if (this->script_options_->saw_sections_clause())
+ increase_relro = 0;
+
const bool check_sections = parameters->options().check_sections();
Output_segment* last_load_segment = NULL;
- bool was_readonly = false;
for (Segment_list::iterator p = this->segment_list_.begin();
p != this->segment_list_.end();
++p)
// the physical address.
addr = (*p)->paddr();
}
- else if (this->options_.user_set_Tdata()
+ else if (parameters->options().user_set_Tdata()
&& ((*p)->flags() & elfcpp::PF_W) != 0
- && (!this->options_.user_set_Tbss()
+ && (!parameters->options().user_set_Tbss()
|| (*p)->has_any_data_sections()))
{
- addr = this->options_.Tdata();
+ addr = parameters->options().Tdata();
are_addresses_set = true;
}
- else if (this->options_.user_set_Tbss()
+ else if (parameters->options().user_set_Tbss()
&& ((*p)->flags() & elfcpp::PF_W) != 0
&& !(*p)->has_any_data_sections())
{
- addr = this->options_.Tbss();
+ addr = parameters->options().Tbss();
are_addresses_set = true;
}
&& !parameters->options().omagic())
(*p)->set_minimum_p_align(common_pagesize);
- if (are_addresses_set)
- {
- if (!parameters->options().nmagic()
- && !parameters->options().omagic())
- {
- // Adjust the file offset to the same address modulo
- // the page size.
- uint64_t unsigned_off = off;
- uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
- | (addr & (abi_pagesize - 1)));
- if (aligned_off < unsigned_off)
- aligned_off += abi_pagesize;
- off = aligned_off;
- }
- }
- else
+ if (!are_addresses_set)
{
- // If the last segment was readonly, and this one is
- // not, then skip the address forward one page,
- // maintaining the same position within the page. This
- // lets us store both segments overlapping on a single
- // page in the file, but the loader will put them on
- // different pages in memory.
+ // Skip the address forward one page, maintaining the same
+ // position within the page. This lets us store both segments
+ // overlapping on a single page in the file, but the loader will
+ // put them on different pages in memory. We will revisit this
+ // decision once we know the size of the segment.
addr = align_address(addr, (*p)->maximum_alignment());
aligned_addr = addr;
- if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
- {
- if ((addr & (abi_pagesize - 1)) != 0)
- addr = addr + abi_pagesize;
- }
+ if ((addr & (abi_pagesize - 1)) != 0)
+ addr = addr + abi_pagesize;
off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
}
+ if (!parameters->options().nmagic()
+ && !parameters->options().omagic())
+ off = align_file_offset(off, addr, abi_pagesize);
+ else if (load_seg == NULL)
+ {
+ // This is -N or -n with a section script which prevents
+ // us from using a load segment. We need to ensure that
+ // the file offset is aligned to the alignment of the
+ // segment. This is because the linker script
+ // implicitly assumed a zero offset. If we don't align
+ // here, then the alignment of the sections in the
+ // linker script may not match the alignment of the
+ // sections in the set_section_addresses call below,
+ // causing an error about dot moving backward.
+ off = align_address(off, (*p)->maximum_alignment());
+ }
+
unsigned int shndx_hold = *pshndx;
+ bool has_relro = false;
uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
+ &increase_relro,
+ &has_relro,
&off, pshndx);
// Now that we know the size of this segment, we may be able
// to save a page in memory, at the cost of wasting some
// file space, by instead aligning to the start of a new
// page. Here we use the real machine page size rather than
- // the ABI mandated page size.
-
- if (!are_addresses_set && aligned_addr != addr)
+ // the ABI mandated page size. If the segment has been
+ // aligned so that the relro data ends at a page boundary,
+ // we do not try to realign it.
+
+ if (!are_addresses_set
+ && !has_relro
+ && aligned_addr != addr
+ && !parameters->incremental_update())
{
uint64_t first_off = (common_pagesize
- (aligned_addr
addr = align_address(aligned_addr, common_pagesize);
addr = align_address(addr, (*p)->maximum_alignment());
off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
+ off = align_file_offset(off, addr, abi_pagesize);
+
+ increase_relro = this->increase_relro_;
+ if (this->script_options_->saw_sections_clause())
+ increase_relro = 0;
+ has_relro = false;
+
new_addr = (*p)->set_section_addresses(this, true, addr,
+ &increase_relro,
+ &has_relro,
&off, pshndx);
}
}
addr = new_addr;
- if (((*p)->flags() & elfcpp::PF_W) == 0)
- was_readonly = true;
-
// Implement --check-sections. We know that the segments
// are sorted by LMA.
if (check_sections && last_load_segment != NULL)
++p)
{
if ((*p)->type() != elfcpp::PT_LOAD)
- (*p)->set_offset();
+ (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO
+ ? increase_relro
+ : 0);
}
// Set the TLS offsets for each section in the PT_TLS segment.
off_t
Layout::set_relocatable_section_offsets(Output_data* file_header,
- unsigned int *pshndx)
+ unsigned int* pshndx)
{
off_t off = 0;
off_t
Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
{
+ off_t startoff = off;
+ off_t maxoff = off;
+
for (Section_list::iterator p = this->unattached_section_list_.begin();
p != this->unattached_section_list_.end();
++p)
|| (*p)->type() != elfcpp::SHT_STRTAB))
continue;
- off = align_address(off, (*p)->addralign());
- (*p)->set_file_offset(off);
- (*p)->finalize_data_size();
+ if (!parameters->incremental_update())
+ {
+ off = align_address(off, (*p)->addralign());
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
+ }
+ else
+ {
+ // Incremental update: allocate file space from free list.
+ (*p)->pre_finalize_data_size();
+ off_t current_size = (*p)->current_data_size();
+ off = this->allocate(current_size, (*p)->addralign(), startoff);
+ if (off == -1)
+ {
+ if (is_debugging_enabled(DEBUG_INCREMENTAL))
+ this->free_list_.dump();
+ gold_assert((*p)->output_section() != NULL);
+ gold_fatal(_("out of patch space for section %s; "
+ "relink with --incremental-full"),
+ (*p)->output_section()->name());
+ }
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
+ if ((*p)->data_size() > current_size)
+ {
+ gold_assert((*p)->output_section() != NULL);
+ gold_fatal(_("%s: section changed size; "
+ "relink with --incremental-full"),
+ (*p)->output_section()->name());
+ }
+ gold_debug(DEBUG_INCREMENTAL,
+ "set_section_offsets: %08lx %08lx %s",
+ static_cast<long>(off),
+ static_cast<long>((*p)->data_size()),
+ ((*p)->output_section() != NULL
+ ? (*p)->output_section()->name() : "(special)"));
+ }
+
off += (*p)->data_size();
+ if (off > maxoff)
+ maxoff = off;
// At this point the name must be set.
if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
this->namepool_.add((*p)->name(), false, NULL);
}
- return off;
+ return maxoff;
}
// Set the section indexes of all the sections not associated with a
Output_segment*
Layout::set_section_addresses_from_script(Symbol_table* symtab)
+{
+ Script_sections* ss = this->script_options_->script_sections();
+ gold_assert(ss->saw_sections_clause());
+ return this->script_options_->set_section_addresses(symtab, this);
+}
+
+// Place the orphan sections in the linker script.
+
+void
+Layout::place_orphan_sections_in_script()
{
Script_sections* ss = this->script_options_->script_sections();
gold_assert(ss->saw_sections_clause());
if (!(*p)->found_in_sections_clause())
ss->place_orphan(*p);
}
-
- return this->script_options_->set_section_addresses(symtab, this);
}
// Count the local symbols in the regular symbol table and the dynamic
else
gold_unreachable();
- off_t off = *poff;
- off = align_address(off, align);
- off_t startoff = off;
+ // Compute file offsets relative to the start of the symtab section.
+ off_t off = 0;
// Save space for the dummy symbol at the start of the section. We
// never bother to write this out--it will just be left as zero.
++p)
{
unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
- off);
+ off, symtab);
off += (index - local_symbol_index) * symsize;
local_symbol_index = index;
}
unsigned int local_symcount = local_symbol_index;
- gold_assert(local_symcount * symsize == off - startoff);
+ gold_assert(static_cast<off_t>(local_symcount * symsize) == off);
off_t dynoff;
size_t dyn_global_index;
== this->dynsym_section_->data_size() - locsize);
}
+ off_t global_off = off;
off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
&this->sympool_, &local_symcount);
const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
Output_section* osymtab = this->make_output_section(symtab_name,
elfcpp::SHT_SYMTAB,
- 0);
+ 0, ORDER_INVALID,
+ false);
this->symtab_section_ = osymtab;
- Output_section_data* pos = new Output_data_fixed_space(off - startoff,
- align,
+ Output_section_data* pos = new Output_data_fixed_space(off, align,
"** symtab");
osymtab->add_output_section_data(pos);
false, NULL);
Output_section* osymtab_xindex =
this->make_output_section(symtab_xindex_name,
- elfcpp::SHT_SYMTAB_SHNDX, 0);
+ elfcpp::SHT_SYMTAB_SHNDX, 0,
+ ORDER_INVALID, false);
- size_t symcount = (off - startoff) / symsize;
+ size_t symcount = off / symsize;
this->symtab_xindex_ = new Output_symtab_xindex(symcount);
osymtab_xindex->add_output_section_data(this->symtab_xindex_);
const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
Output_section* ostrtab = this->make_output_section(strtab_name,
elfcpp::SHT_STRTAB,
- 0);
+ 0, ORDER_INVALID,
+ false);
Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
ostrtab->add_output_section_data(pstr);
- osymtab->set_file_offset(startoff);
+ off_t symtab_off;
+ if (!parameters->incremental_update())
+ symtab_off = align_address(*poff, align);
+ else
+ {
+ symtab_off = this->allocate(off, align, *poff);
+ if (off == -1)
+ gold_fatal(_("out of patch space for symbol table; "
+ "relink with --incremental-full"));
+ gold_debug(DEBUG_INCREMENTAL,
+ "create_symtab_sections: %08lx %08lx .symtab",
+ static_cast<long>(symtab_off),
+ static_cast<long>(off));
+ }
+
+ symtab->set_file_offset(symtab_off + global_off);
+ osymtab->set_file_offset(symtab_off);
osymtab->finalize_data_size();
osymtab->set_link_section(ostrtab);
osymtab->set_info(local_symcount);
osymtab->set_entsize(symsize);
- *poff = off;
+ if (symtab_off + off > *poff)
+ *poff = symtab_off + off;
}
}
const char* name = this->namepool_.add(".shstrtab", false, NULL);
- Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0);
+ Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0,
+ ORDER_INVALID, false);
- // We can't write out this section until we've set all the section
- // names, and we don't set the names of compressed output sections
- // until relocations are complete.
- os->set_after_input_sections();
+ if (strcmp(parameters->options().compress_debug_sections(), "none") != 0)
+ {
+ // We can't write out this section until we've set all the
+ // section names, and we don't set the names of compressed
+ // output sections until relocations are complete. FIXME: With
+ // the current names we use, this is unnecessary.
+ os->set_after_input_sections();
+ }
Output_section_data* posd = new Output_data_strtab(&this->namepool_);
os->add_output_section_data(posd);
&this->unattached_section_list_,
&this->namepool_,
shstrtab_section);
- off_t off = align_address(*poff, oshdrs->addralign());
+ off_t off;
+ if (!parameters->incremental_update())
+ off = align_address(*poff, oshdrs->addralign());
+ else
+ {
+ oshdrs->pre_finalize_data_size();
+ off = this->allocate(oshdrs->data_size(), oshdrs->addralign(), *poff);
+ if (off == -1)
+ gold_fatal(_("out of patch space for section header table; "
+ "relink with --incremental-full"));
+ gold_debug(DEBUG_INCREMENTAL,
+ "create_shdrs: %08lx %08lx (section header table)",
+ static_cast<long>(off),
+ static_cast<long>(off + oshdrs->data_size()));
+ }
oshdrs->set_address_and_file_offset(0, off);
off += oshdrs->data_size();
- *poff = off;
+ if (off > *poff)
+ *poff = off;
this->section_headers_ = oshdrs;
}
void
Layout::create_dynamic_symtab(const Input_objects* input_objects,
Symbol_table* symtab,
- Output_section **pdynstr,
+ Output_section** pdynstr,
unsigned int* plocal_dynamic_count,
std::vector<Symbol*>* pdynamic_symbols,
Versions* pversions)
Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
elfcpp::SHT_DYNSYM,
elfcpp::SHF_ALLOC,
+ false,
+ ORDER_DYNAMIC_LINKER,
false);
Output_section_data* odata = new Output_data_fixed_space(index * symsize,
this->choose_output_section(NULL, ".dynsym_shndx",
elfcpp::SHT_SYMTAB_SHNDX,
elfcpp::SHF_ALLOC,
- false);
+ false, ORDER_DYNAMIC_LINKER, false);
this->dynsym_xindex_ = new Output_symtab_xindex(index);
Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
elfcpp::SHT_STRTAB,
elfcpp::SHF_ALLOC,
+ false,
+ ORDER_DYNAMIC_LINKER,
false);
Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
&phash, &hashlen);
- Output_section* hashsec = this->choose_output_section(NULL, ".hash",
- elfcpp::SHT_HASH,
- elfcpp::SHF_ALLOC,
- false);
+ Output_section* hashsec =
+ this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH,
+ elfcpp::SHF_ALLOC, false,
+ ORDER_DYNAMIC_LINKER, false);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
&phash, &hashlen);
- Output_section* hashsec = this->choose_output_section(NULL, ".gnu.hash",
- elfcpp::SHT_GNU_HASH,
- elfcpp::SHF_ALLOC,
- false);
+ Output_section* hashsec =
+ this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH,
+ elfcpp::SHF_ALLOC, false,
+ ORDER_DYNAMIC_LINKER, false);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
hashsec->add_output_section_data(hashdata);
hashsec->set_link_section(dynsym);
- hashsec->set_entsize(4);
+
+ // For a 64-bit target, the entries in .gnu.hash do not have a
+ // uniform size, so we only set the entry size for a 32-bit
+ // target.
+ if (parameters->target().get_size() == 32)
+ hashsec->set_entsize(4);
odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
}
Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
elfcpp::SHT_GNU_versym,
elfcpp::SHF_ALLOC,
+ false,
+ ORDER_DYNAMIC_LINKER,
false);
unsigned char* vbuf;
vdsec= this->choose_output_section(NULL, ".gnu.version_d",
elfcpp::SHT_GNU_verdef,
elfcpp::SHF_ALLOC,
- false);
+ false, ORDER_DYNAMIC_LINKER, false);
unsigned char* vdbuf;
unsigned int vdsize;
vnsec = this->choose_output_section(NULL, ".gnu.version_r",
elfcpp::SHT_GNU_verneed,
elfcpp::SHF_ALLOC,
- false);
+ false, ORDER_DYNAMIC_LINKER, false);
unsigned char* vnbuf;
unsigned int vnsize;
void
Layout::create_interp(const Target* target)
{
- const char* interp = this->options_.dynamic_linker();
+ const char* interp = parameters->options().dynamic_linker();
if (interp == NULL)
{
interp = target->dynamic_linker();
Output_section* osec = this->choose_output_section(NULL, ".interp",
elfcpp::SHT_PROGBITS,
elfcpp::SHF_ALLOC,
+ false, ORDER_INTERP,
false);
osec->add_output_section_data(odata);
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
elfcpp::PF_R);
- oseg->add_output_section(osec, elfcpp::PF_R);
+ oseg->add_output_section_to_nonload(osec, elfcpp::PF_R);
+ }
+}
+
+// Add dynamic tags for the PLT and the dynamic relocs. This is
+// called by the target-specific code. This does nothing if not doing
+// a dynamic link.
+
+// USE_REL is true for REL relocs rather than RELA relocs.
+
+// If PLT_GOT is not NULL, then DT_PLTGOT points to it.
+
+// If PLT_REL is not NULL, it is used for DT_PLTRELSZ, and DT_JMPREL,
+// and we also set DT_PLTREL. We use PLT_REL's output section, since
+// some targets have multiple reloc sections in PLT_REL.
+
+// If DYN_REL is not NULL, it is used for DT_REL/DT_RELA,
+// DT_RELSZ/DT_RELASZ, DT_RELENT/DT_RELAENT.
+
+// If ADD_DEBUG is true, we add a DT_DEBUG entry when generating an
+// executable.
+
+void
+Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
+ const Output_data* plt_rel,
+ const Output_data_reloc_generic* dyn_rel,
+ bool add_debug, bool dynrel_includes_plt)
+{
+ Output_data_dynamic* odyn = this->dynamic_data_;
+ if (odyn == NULL)
+ return;
+
+ if (plt_got != NULL && plt_got->output_section() != NULL)
+ odyn->add_section_address(elfcpp::DT_PLTGOT, plt_got);
+
+ if (plt_rel != NULL && plt_rel->output_section() != NULL)
+ {
+ odyn->add_section_size(elfcpp::DT_PLTRELSZ, plt_rel->output_section());
+ odyn->add_section_address(elfcpp::DT_JMPREL, plt_rel->output_section());
+ odyn->add_constant(elfcpp::DT_PLTREL,
+ use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA);
+ }
+
+ if (dyn_rel != NULL && dyn_rel->output_section() != NULL)
+ {
+ odyn->add_section_address(use_rel ? elfcpp::DT_REL : elfcpp::DT_RELA,
+ dyn_rel);
+ if (plt_rel != NULL && dynrel_includes_plt)
+ odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
+ dyn_rel, plt_rel);
+ else
+ odyn->add_section_size(use_rel ? elfcpp::DT_RELSZ : elfcpp::DT_RELASZ,
+ dyn_rel);
+ const int size = parameters->target().get_size();
+ elfcpp::DT rel_tag;
+ int rel_size;
+ if (use_rel)
+ {
+ rel_tag = elfcpp::DT_RELENT;
+ if (size == 32)
+ rel_size = Reloc_types<elfcpp::SHT_REL, 32, false>::reloc_size;
+ else if (size == 64)
+ rel_size = Reloc_types<elfcpp::SHT_REL, 64, false>::reloc_size;
+ else
+ gold_unreachable();
+ }
+ else
+ {
+ rel_tag = elfcpp::DT_RELAENT;
+ if (size == 32)
+ rel_size = Reloc_types<elfcpp::SHT_RELA, 32, false>::reloc_size;
+ else if (size == 64)
+ rel_size = Reloc_types<elfcpp::SHT_RELA, 64, false>::reloc_size;
+ else
+ gold_unreachable();
+ }
+ odyn->add_constant(rel_tag, rel_size);
+
+ if (parameters->options().combreloc())
+ {
+ size_t c = dyn_rel->relative_reloc_count();
+ if (c > 0)
+ odyn->add_constant((use_rel
+ ? elfcpp::DT_RELCOUNT
+ : elfcpp::DT_RELACOUNT),
+ c);
+ }
+ }
+
+ if (add_debug && !parameters->options().shared())
+ {
+ // The value of the DT_DEBUG tag is filled in by the dynamic
+ // linker at run time, and used by the debugger.
+ odyn->add_constant(elfcpp::DT_DEBUG, 0);
}
}
Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
(elfcpp::PF_R
| elfcpp::PF_W));
- oseg->add_output_section(this->dynamic_section_,
- elfcpp::PF_R | elfcpp::PF_W);
+ oseg->add_output_section_to_nonload(this->dynamic_section_,
+ elfcpp::PF_R | elfcpp::PF_W);
}
Output_data_dynamic* const odyn = this->dynamic_data_;
p != input_objects->dynobj_end();
++p)
{
- // FIXME: Handle --as-needed.
+ if (!(*p)->is_needed()
+ && !(*p)->is_incremental()
+ && (*p)->input_file()->options().as_needed())
+ {
+ // This dynamic object was linked with --as-needed, but it
+ // is not needed.
+ continue;
+ }
+
odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
}
if (parameters->options().shared())
{
- const char* soname = this->options_.soname();
+ const char* soname = parameters->options().soname();
if (soname != NULL)
odyn->add_string(elfcpp::DT_SONAME, soname);
}
- // FIXME: Support --init and --fini.
- Symbol* sym = symtab->lookup("_init");
+ Symbol* sym = symtab->lookup(parameters->options().init());
if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
odyn->add_symbol(elfcpp::DT_INIT, sym);
- sym = symtab->lookup("_fini");
+ sym = symtab->lookup(parameters->options().fini());
if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
odyn->add_symbol(elfcpp::DT_FINI, sym);
- // FIXME: Support DT_INIT_ARRAY and DT_FINI_ARRAY.
-
+ // Look for .init_array, .preinit_array and .fini_array by checking
+ // section types.
+ for(Layout::Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ switch((*p)->type())
+ {
+ case elfcpp::SHT_FINI_ARRAY:
+ odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p);
+ odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p);
+ break;
+ case elfcpp::SHT_INIT_ARRAY:
+ odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p);
+ odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p);
+ break;
+ case elfcpp::SHT_PREINIT_ARRAY:
+ odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p);
+ odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p);
+ break;
+ default:
+ break;
+ }
+
// Add a DT_RPATH entry if needed.
- const General_options::Dir_list& rpath(this->options_.rpath());
+ const General_options::Dir_list& rpath(parameters->options().rpath());
if (!rpath.empty())
{
std::string rpath_val;
++p)
{
if (((*p)->flags() & elfcpp::PF_W) == 0
- && (*p)->dynamic_reloc_count() > 0)
+ && (*p)->has_dynamic_reloc())
{
have_textrel = true;
break;
{
if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
&& ((*p)->flags() & elfcpp::SHF_WRITE) == 0
- && ((*p)->dynamic_reloc_count() > 0))
+ && ((*p)->has_dynamic_reloc()))
{
have_textrel = true;
break;
// Add a DT_TEXTREL for compatibility with older loaders.
odyn->add_constant(elfcpp::DT_TEXTREL, 0);
flags |= elfcpp::DF_TEXTREL;
+
+ if (parameters->options().text())
+ gold_error(_("read-only segment has dynamic relocations"));
+ else if (parameters->options().warn_shared_textrel()
+ && parameters->options().shared())
+ gold_warning(_("shared library text segment is not shareable"));
}
if (parameters->options().shared() && this->has_static_tls())
flags |= elfcpp::DF_STATIC_TLS;
if (parameters->options().origin())
flags |= elfcpp::DF_ORIGIN;
+ if (parameters->options().Bsymbolic())
+ {
+ flags |= elfcpp::DF_SYMBOLIC;
+ // Add DT_SYMBOLIC for compatibility with older loaders.
+ odyn->add_constant(elfcpp::DT_SYMBOLIC, 0);
+ }
+ if (parameters->options().now())
+ flags |= elfcpp::DF_BIND_NOW;
odyn->add_constant(elfcpp::DT_FLAGS, flags);
flags = 0;
| elfcpp::DF_1_NOOPEN);
if (parameters->options().origin())
flags |= elfcpp::DF_1_ORIGIN;
+ if (parameters->options().now())
+ flags |= elfcpp::DF_1_NOW;
if (flags)
odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
}
-// The mapping of .gnu.linkonce section names to real section names.
+// Set the size of the _DYNAMIC symbol table to be the size of the
+// dynamic data.
+
+void
+Layout::set_dynamic_symbol_size(const Symbol_table* symtab)
+{
+ Output_data_dynamic* const odyn = this->dynamic_data_;
+ odyn->finalize_data_size();
+ off_t data_size = odyn->data_size();
+ const int size = parameters->target().get_size();
+ if (size == 32)
+ symtab->get_sized_symbol<32>(this->dynamic_symbol_)->set_symsize(data_size);
+ else if (size == 64)
+ symtab->get_sized_symbol<64>(this->dynamic_symbol_)->set_symsize(data_size);
+ else
+ gold_unreachable();
+}
+
+// The mapping of input section name prefixes to output section names.
+// In some cases one prefix is itself a prefix of another prefix; in
+// such a case the longer prefix must come first. These prefixes are
+// based on the GNU linker default ELF linker script.
#define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
-const Layout::Linkonce_mapping Layout::linkonce_mapping[] =
-{
- MAPPING_INIT("d.rel.ro.local", ".data.rel.ro.local"), // Before "d.rel.ro".
- MAPPING_INIT("d.rel.ro", ".data.rel.ro"), // Before "d".
- MAPPING_INIT("t", ".text"),
- MAPPING_INIT("r", ".rodata"),
- MAPPING_INIT("d", ".data"),
- MAPPING_INIT("b", ".bss"),
- MAPPING_INIT("s", ".sdata"),
- MAPPING_INIT("sb", ".sbss"),
- MAPPING_INIT("s2", ".sdata2"),
- MAPPING_INIT("sb2", ".sbss2"),
- MAPPING_INIT("wi", ".debug_info"),
- MAPPING_INIT("td", ".tdata"),
- MAPPING_INIT("tb", ".tbss"),
- MAPPING_INIT("lr", ".lrodata"),
- MAPPING_INIT("l", ".ldata"),
- MAPPING_INIT("lb", ".lbss"),
+const Layout::Section_name_mapping Layout::section_name_mapping[] =
+{
+ MAPPING_INIT(".text.", ".text"),
+ MAPPING_INIT(".ctors.", ".ctors"),
+ MAPPING_INIT(".dtors.", ".dtors"),
+ MAPPING_INIT(".rodata.", ".rodata"),
+ MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
+ MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
+ MAPPING_INIT(".data.", ".data"),
+ MAPPING_INIT(".bss.", ".bss"),
+ MAPPING_INIT(".tdata.", ".tdata"),
+ MAPPING_INIT(".tbss.", ".tbss"),
+ MAPPING_INIT(".init_array.", ".init_array"),
+ MAPPING_INIT(".fini_array.", ".fini_array"),
+ MAPPING_INIT(".sdata.", ".sdata"),
+ MAPPING_INIT(".sbss.", ".sbss"),
+ // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
+ // differently depending on whether it is creating a shared library.
+ MAPPING_INIT(".sdata2.", ".sdata"),
+ MAPPING_INIT(".sbss2.", ".sbss"),
+ MAPPING_INIT(".lrodata.", ".lrodata"),
+ MAPPING_INIT(".ldata.", ".ldata"),
+ MAPPING_INIT(".lbss.", ".lbss"),
+ MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
+ MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
+ MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
+ MAPPING_INIT(".gnu.linkonce.t.", ".text"),
+ MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
+ MAPPING_INIT(".gnu.linkonce.d.", ".data"),
+ MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
+ MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
+ MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
+ MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
+ MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
+ MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
+ MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
+ MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
+ MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
+ MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
+ MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
+ MAPPING_INIT(".ARM.extab", ".ARM.extab"),
+ MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
+ MAPPING_INIT(".ARM.exidx", ".ARM.exidx"),
+ MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
};
#undef MAPPING_INIT
-const int Layout::linkonce_mapping_count =
- sizeof(Layout::linkonce_mapping) / sizeof(Layout::linkonce_mapping[0]);
-
-// Return the name of the output section to use for a .gnu.linkonce
-// section. This is based on the default ELF linker script of the old
-// GNU linker. For example, we map a name like ".gnu.linkonce.t.foo"
-// to ".text". Set *PLEN to the length of the name. *PLEN is
-// initialized to the length of NAME.
-
-const char*
-Layout::linkonce_output_name(const char* name, size_t *plen)
-{
- const char* s = name + sizeof(".gnu.linkonce") - 1;
- if (*s != '.')
- return name;
- ++s;
- const Linkonce_mapping* plm = linkonce_mapping;
- for (int i = 0; i < linkonce_mapping_count; ++i, ++plm)
- {
- if (strncmp(s, plm->from, plm->fromlen) == 0 && s[plm->fromlen] == '.')
- {
- *plen = plm->tolen;
- return plm->to;
- }
- }
- return name;
-}
+const int Layout::section_name_mapping_count =
+ (sizeof(Layout::section_name_mapping)
+ / sizeof(Layout::section_name_mapping[0]));
// Choose the output section name to use given an input section name.
// Set *PLEN to the length of the name. *PLEN is initialized to the
const char*
Layout::output_section_name(const char* name, size_t* plen)
{
- if (Layout::is_linkonce(name))
- {
- // .gnu.linkonce sections are laid out as though they were named
- // for the sections are placed into.
- return Layout::linkonce_output_name(name, plen);
- }
-
// gcc 4.3 generates the following sorts of section names when it
// needs a section name specific to a function:
// .text.FN
// Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
// GNU linker maps to .rodata.
- // The .data.rel.ro sections enable a security feature triggered by
- // the -z relro option. Section which need to be relocated at
- // program startup time but which may be readonly after startup are
- // grouped into .data.rel.ro. They are then put into a PT_GNU_RELRO
- // segment. The dynamic linker will make that segment writable,
- // perform relocations, and then make it read-only. FIXME: We do
- // not yet implement this optimization.
-
- // It is hard to handle this in a principled way.
-
- // These are the rules we follow:
-
- // If the section name has no initial '.', or no dot other than an
- // initial '.', we use the name unchanged (i.e., "mysection" and
- // ".text" are unchanged).
-
- // If the name starts with ".data.rel.ro.local" we use
- // ".data.rel.ro.local".
-
- // If the name starts with ".data.rel.ro" we use ".data.rel.ro".
+ // The .data.rel.ro sections are used with -z relro. The sections
+ // are recognized by name. We use the same names that the GNU
+ // linker does for these sections.
- // Otherwise, we drop the second '.' and everything that comes after
- // it (i.e., ".text.XXX" becomes ".text").
+ // It is hard to handle this in a principled way, so we don't even
+ // try. We use a table of mappings. If the input section name is
+ // not found in the table, we simply use it as the output section
+ // name.
- const char* s = name;
- if (*s != '.')
- return name;
- ++s;
- const char* sdot = strchr(s, '.');
- if (sdot == NULL)
- return name;
-
- const char* const data_rel_ro_local = ".data.rel.ro.local";
- if (strncmp(name, data_rel_ro_local, strlen(data_rel_ro_local)) == 0)
- {
- *plen = strlen(data_rel_ro_local);
- return data_rel_ro_local;
- }
-
- const char* const data_rel_ro = ".data.rel.ro";
- if (strncmp(name, data_rel_ro, strlen(data_rel_ro)) == 0)
+ const Section_name_mapping* psnm = section_name_mapping;
+ for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
{
- *plen = strlen(data_rel_ro);
- return data_rel_ro;
+ if (strncmp(name, psnm->from, psnm->fromlen) == 0)
+ {
+ *plen = psnm->tolen;
+ return psnm->to;
+ }
}
- *plen = sdot - name;
return name;
}
-// Record the signature of a comdat section, and return whether to
-// include it in the link. If GROUP is true, this is a regular
-// section group. If GROUP is false, this is a group signature
-// derived from the name of a linkonce section. We want linkonce
-// signatures and group signatures to block each other, but we don't
-// want a linkonce signature to block another linkonce signature.
+// Check if a comdat group or .gnu.linkonce section with the given
+// NAME is selected for the link. If there is already a section,
+// *KEPT_SECTION is set to point to the existing section and the
+// function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
+// IS_GROUP_NAME are recorded for this NAME in the layout object,
+// *KEPT_SECTION is set to the internal copy and the function returns
+// true.
bool
-Layout::add_comdat(Relobj* object, unsigned int shndx,
- const std::string& signature, bool group)
+Layout::find_or_add_kept_section(const std::string& name,
+ Relobj* object,
+ unsigned int shndx,
+ bool is_comdat,
+ bool is_group_name,
+ Kept_section** kept_section)
{
- Kept_section kept(object, shndx, group);
- std::pair<Signatures::iterator, bool> ins(
- this->signatures_.insert(std::make_pair(signature, kept)));
+ // It's normal to see a couple of entries here, for the x86 thunk
+ // sections. If we see more than a few, we're linking a C++
+ // program, and we resize to get more space to minimize rehashing.
+ if (this->signatures_.size() > 4
+ && !this->resized_signatures_)
+ {
+ reserve_unordered_map(&this->signatures_,
+ this->number_of_input_files_ * 64);
+ this->resized_signatures_ = true;
+ }
+ Kept_section candidate;
+ std::pair<Signatures::iterator, bool> ins =
+ this->signatures_.insert(std::make_pair(name, candidate));
+
+ if (kept_section != NULL)
+ *kept_section = &ins.first->second;
if (ins.second)
{
// This is the first time we've seen this signature.
+ ins.first->second.set_object(object);
+ ins.first->second.set_shndx(shndx);
+ if (is_comdat)
+ ins.first->second.set_is_comdat();
+ if (is_group_name)
+ ins.first->second.set_is_group_name();
return true;
}
- if (ins.first->second.group_)
+ // We have already seen this signature.
+
+ if (ins.first->second.is_group_name())
{
// We've already seen a real section group with this signature.
- // If the kept group is from a plugin object, and we're in
- // the replacement phase, accept the new one as a replacement.
- if (ins.first->second.object_ == NULL
+ // If the kept group is from a plugin object, and we're in the
+ // replacement phase, accept the new one as a replacement.
+ if (ins.first->second.object() == NULL
&& parameters->options().plugins()->in_replacement_phase())
{
- ins.first->second = kept;
+ ins.first->second.set_object(object);
+ ins.first->second.set_shndx(shndx);
return true;
}
return false;
}
- else if (group)
+ else if (is_group_name)
{
// This is a real section group, and we've already seen a
// linkonce section with this signature. Record that we've seen
// a section group, and don't include this section group.
- ins.first->second.group_ = true;
+ ins.first->second.set_is_group_name();
return false;
}
else
}
}
-// Find the given comdat signature, and return the object and section
-// index of the kept group.
-Relobj*
-Layout::find_kept_object(const std::string& signature,
- unsigned int* pshndx) const
-{
- Signatures::const_iterator p = this->signatures_.find(signature);
- if (p == this->signatures_.end())
- return NULL;
- if (pshndx != NULL)
- *pshndx = p->second.shndx_;
- return p->second.object_;
-}
-
// Store the allocated sections into the section list.
void
return oseg;
}
+// Return the file offset of the normal symbol table.
+
+off_t
+Layout::symtab_section_offset() const
+{
+ if (this->symtab_section_ != NULL)
+ return this->symtab_section_->offset();
+ return 0;
+}
+
// Write out the Output_sections. Most won't have anything to write,
// since most of the data will come from input sections which are
// handled elsewhere. But some Output_sections do have Output_data.
{
off_t off = this->output_file_size_;
off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
-
+
// Now that we've finalized the names, we can finalize the shstrab.
off =
this->set_section_offsets(off,
void
Layout::write_binary(Output_file* in) const
{
- gold_assert(this->options_.oformat_enum()
+ gold_assert(parameters->options().oformat_enum()
== General_options::OBJECT_FORMAT_BINARY);
// Get the size of the binary file.
void
Write_symbols_task::run(Workqueue*)
{
- this->symtab_->write_globals(this->input_objects_, this->sympool_,
- this->dynpool_, this->layout_->symtab_xindex(),
+ this->symtab_->write_globals(this->sympool_, this->dynpool_,
+ this->layout_->symtab_xindex(),
this->layout_->dynsym_xindex(), this->of_);
}
// Instantiate the templates we need. We could use the configure
// script to restrict this to only the ones for implemented targets.
+#ifdef HAVE_TARGET_32_LITTLE
+template
+Output_section*
+Layout::init_fixed_output_section<32, false>(
+ const char* name,
+ elfcpp::Shdr<32, false>& shdr);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+Output_section*
+Layout::init_fixed_output_section<32, true>(
+ const char* name,
+ elfcpp::Shdr<32, true>& shdr);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+Output_section*
+Layout::init_fixed_output_section<64, false>(
+ const char* name,
+ elfcpp::Shdr<64, false>& shdr);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+Output_section*
+Layout::init_fixed_output_section<64, true>(
+ const char* name,
+ elfcpp::Shdr<64, true>& shdr);
+#endif
+
#ifdef HAVE_TARGET_32_LITTLE
template
Output_section*