#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
{
+// 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
// 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),
debug_info_(NULL),
group_signatures_(),
output_file_size_(-1),
+ 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)
{
// 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->options().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.
// 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.
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,
+ bool is_interp, bool is_dynamic_linker_section)
{
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, is_interp,
+ is_dynamic_linker_section);
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. 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, bool is_interp,
+ bool is_dynamic_linker_section)
{
// We should not see any input sections after we have attached
// sections to segments.
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, is_interp,
+ is_dynamic_linker_section);
os->set_found_in_sections_clause();
*output_section_slot = os;
return os;
// 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, is_interp,
+ is_dynamic_linker_section);
}
// Return the output section to use for input section SHNDX, with name
{
name = this->namepool_.add(name, true, NULL);
os = this->make_output_section(name, shdr.get_sh_type(),
- shdr.get_sh_flags());
+ shdr.get_sh_flags(), false, false);
}
else
{
os = this->choose_output_section(object, name, shdr.get_sh_type(),
- shdr.get_sh_flags(), true);
+ shdr.get_sh_flags(), true, false,
+ false);
if (os == NULL)
return NULL;
}
Output_section* os = this->choose_output_section(object, name.c_str(),
sh_type,
shdr.get_sh_flags(),
- false);
+ false, false, 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(),
+ false, 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);
name,
elfcpp::SHT_PROGBITS,
elfcpp::SHF_ALLOC,
- false);
+ false, false, false);
if (os == NULL)
return NULL;
this->eh_frame_section_ = os;
this->eh_frame_data_ = new Eh_frame();
- if (this->options_.eh_frame_hdr())
+ if (parameters->options().eh_frame_hdr())
{
Output_section* hdr_os =
this->choose_output_section(NULL,
".eh_frame_hdr",
elfcpp::SHT_PROGBITS,
elfcpp::SHF_ALLOC,
- false);
+ false, false, 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(hdr_os, elfcpp::PF_R, false);
}
this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
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,
+ bool is_dynamic_linker_section)
{
Output_section* os = this->choose_output_section(NULL, name, type, flags,
- false);
+ false, false,
+ is_dynamic_linker_section);
if (os != NULL)
os->add_output_section_data(posd);
return os;
// 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.
+// 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)
}
// Make a new Output_section, and attach it to segments as
-// appropriate.
+// appropriate. 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.
Output_section*
Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
- elfcpp::Elf_Xword flags)
+ elfcpp::Elf_Xword flags, bool is_interp,
+ bool is_dynamic_linker_section)
{
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(
this->debug_info_->set_abbreviations(this->debug_abbrev_);
}
else
- os = new Output_section(name, type, flags);
+ {
+ // FIXME: const_cast is ugly.
+ Target* target = const_cast<Target*>(¶meters->target());
+ os = target->make_output_section(name, type, flags);
+ }
+
+ if (is_interp)
+ os->set_is_interp();
+ if (is_dynamic_linker_section)
+ os->set_is_dynamic_linker_section();
+
+ parameters->target().new_output_section(os);
this->section_list_.push_back(os);
}
}
+ // 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.
elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
+ bool sort_sections = !this->script_options_->saw_sections_clause();
+
// 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
+ // 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;
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 -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;
- }
+ (*p)->add_output_section(os, seg_flags, sort_sections);
+ 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(os, seg_flags, sort_sections);
}
// 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(os, seg_flags, false);
break;
}
}
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
seg_flags);
- oseg->add_output_section(os, seg_flags);
+ oseg->add_output_section(os, seg_flags, false);
}
}
{
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(os, seg_flags, false);
}
// 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(os, seg_flags, false);
}
}
{
name = this->namepool_.add(name, false, NULL);
Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC);
+ elfcpp::SHF_ALLOC, false,
+ false);
os->set_found_in_sections_clause();
return os;
}
}
}
+// 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);
+ false, false, true);
this->dynamic_section_->set_is_relro();
symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
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)->reset_address_and_file_offset();
+ (*p)->restore_states();
+ }
+
+ // 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;
+
+ gold_assert(phdr_seg == NULL
+ || load_seg != NULL
+ || this->script_options_->saw_sections_clause());
+
+ // Lay out the segment headers.
+ if (!parameters->options().relocatable())
+ {
+ gold_assert(segment_headers != NULL);
+ 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;
+}
+
// 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);
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())
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;
-
- gold_assert(phdr_seg == NULL || load_seg != NULL);
-
- // Lay out the segment headers.
- Output_segment_headers* segment_headers;
- if (parameters->options().relocatable())
- segment_headers = NULL;
- else
+
+ if (this->incremental_inputs_)
{
- 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);
+ this->incremental_inputs_->finalize();
+ this->create_incremental_info_sections();
}
+ // 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));
// 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
}
// 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;
if (allocate)
flags = elfcpp::SHF_ALLOC;
- Output_section* os = this->make_output_section(note_name,
- elfcpp::SHT_NOTE,
- flags);
+ Output_section* os = this->choose_output_section(NULL, section_name,
+ elfcpp::SHT_NOTE,
+ flags, false, false,
+ false);
+ if (os == NULL)
+ return NULL;
+
Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
size / 8,
"** note header");
size_t trailing_padding;
Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
- desc.size(), false, &trailing_padding);
+ ".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, false,
+ 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 .gnu_incremental_strtab sections needed
+// for the next run of incremental linking to check what has changed.
+
+void
+Layout::create_incremental_info_sections()
+{
+ gold_assert(this->incremental_inputs_ != NULL);
+
+ // Add the .gnu_incremental_inputs section.
+ const char *incremental_inputs_name =
+ this->namepool_.add(".gnu_incremental_inputs", false, NULL);
+ Output_section* inputs_os =
+ this->make_output_section(incremental_inputs_name,
+ elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0,
+ false, false);
+ Output_section_data* posd =
+ this->incremental_inputs_->create_incremental_inputs_section_data();
+ inputs_os->add_output_section_data(posd);
+
+ // Add the .gnu_incremental_strtab section.
+ const char *incremental_strtab_name =
+ this->namepool_.add(".gnu_incremental_strtab", false, NULL);
+ Output_section* strtab_os = this->make_output_section(incremental_strtab_name,
+ elfcpp::SHT_STRTAB,
+ 0, false, false);
+ Output_data_strtab* strtab_data =
+ new Output_data_strtab(this->incremental_inputs_->get_stringpool());
+ strtab_os->add_output_section_data(strtab_data);
+
+ inputs_os->set_link_section(strtab_data);
+}
+
// 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.
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.
// 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();
// 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,
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;
uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
&off, pshndx);
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);
new_addr = (*p)->set_section_addresses(this, true, addr,
&off, pshndx);
}
{
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());
// Place each orphaned output section in the script.
for (Section_list::iterator p = this->section_list_.begin();
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
++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 - startoff);
off_t dynoff;
size_t dyn_global_index;
const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
Output_section* osymtab = this->make_output_section(symtab_name,
elfcpp::SHT_SYMTAB,
- 0);
+ 0, false, false);
this->symtab_section_ = osymtab;
Output_section_data* pos = new Output_data_fixed_space(off - startoff,
false, NULL);
Output_section* osymtab_xindex =
this->make_output_section(symtab_xindex_name,
- elfcpp::SHT_SYMTAB_SHNDX, 0);
+ elfcpp::SHT_SYMTAB_SHNDX, 0, false,
+ false);
size_t symcount = (off - startoff) / symsize;
this->symtab_xindex_ = new Output_symtab_xindex(symcount);
const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
Output_section* ostrtab = this->make_output_section(strtab_name,
elfcpp::SHT_STRTAB,
- 0);
+ 0, false, false);
Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
ostrtab->add_output_section_data(pstr);
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,
+ false, 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
Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
elfcpp::SHT_DYNSYM,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
Output_section_data* odata = new Output_data_fixed_space(index * symsize,
align,
this->choose_output_section(NULL, ".dynsym_shndx",
elfcpp::SHT_SYMTAB_SHNDX,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
this->dynsym_xindex_ = new Output_symtab_xindex(index);
Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
elfcpp::SHT_STRTAB,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
dynstr->add_output_section_data(strdata);
Output_section* hashsec = this->choose_output_section(NULL, ".hash",
elfcpp::SHT_HASH,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
Output_section* hashsec = this->choose_output_section(NULL, ".gnu.hash",
elfcpp::SHT_GNU_HASH,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
elfcpp::SHT_GNU_versym,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
unsigned char* vbuf;
unsigned int vsize;
vdsec= this->choose_output_section(NULL, ".gnu.version_d",
elfcpp::SHT_GNU_verdef,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
unsigned char* vdbuf;
unsigned int vdsize;
vnsec = this->choose_output_section(NULL, ".gnu.version_r",
elfcpp::SHT_GNU_verneed,
elfcpp::SHF_ALLOC,
- false);
+ false, false, true);
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);
+ false, true, true);
osec->add_output_section_data(odata);
if (!this->script_options_->saw_phdrs_clause())
{
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(osec, elfcpp::PF_R, false);
}
}
(elfcpp::PF_R
| elfcpp::PF_W));
oseg->add_output_section(this->dynamic_section_,
- elfcpp::PF_R | elfcpp::PF_W);
+ elfcpp::PF_R | elfcpp::PF_W,
+ false);
}
Output_data_dynamic* const odyn = this->dynamic_data_;
p != input_objects->dynobj_end();
++p)
{
- // FIXME: Handle --as-needed.
+ if (!(*p)->is_needed()
+ && (*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;
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.
+// 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.
+ // 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.
- // These are the rules we follow:
+ // 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.
- // 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".
-
- // Otherwise, we drop the second '.' and everything that comes after
- // it (i.e., ".text.XXX" becomes ".text").
-
- 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)
+ const Section_name_mapping* psnm = section_name_mapping;
+ for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
{
- *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)
- {
- *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;
}
// 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 signature and the function
-// returns false. Otherwise, the CANDIDATE signature is recorded for
-// this NAME in the layout object, *KEPT_SECTION is set to the
-// internal copy and the function return false. In some cases, with
-// CANDIDATE->GROUP_ being false, KEPT_SECTION can point back to
-// CANDIDATE.
+// *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::find_or_add_kept_section(const std::string name,
- Kept_section* candidate,
+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)
{
- std::pair<Signatures::iterator, bool> ins(
- this->signatures_.insert(std::make_pair(name, *candidate)));
+ // 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;
+ }
- if (kept_section)
+ 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.is_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 = *candidate;
+ ins.first->second.set_object(object);
+ ins.first->second.set_shndx(shndx);
return true;
}
return false;
}
- else if (candidate->is_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.is_group = true;
+ ins.first->second.set_is_group_name();
return false;
}
else
// We've already seen a linkonce section and this is a linkonce
// section. These don't block each other--this may be the same
// symbol name with different section types.
- *kept_section = candidate;
return true;
}
}
-// 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
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.
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