// layout.cc -- lay out output file sections for gold
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "parameters.h"
#include "options.h"
+#include "mapfile.h"
#include "script.h"
#include "script-sections.h"
#include "output.h"
#include "dynobj.h"
#include "ehframe.h"
#include "compressed_output.h"
+#include "reduced_debug_output.h"
#include "reloc.h"
+#include "descriptors.h"
+#include "plugin.h"
+#include "incremental.h"
#include "layout.h"
namespace gold
// Now we know the final size of the output file and we know where
// each piece of information goes.
+
+ if (this->mapfile_ != NULL)
+ {
+ this->mapfile_->print_discarded_sections(this->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();
// Layout methods.
-Layout::Layout(const General_options& options, Script_options* script_options)
- : options_(options), script_options_(script_options), namepool_(),
- sympool_(), dynpool_(), signatures_(),
- section_name_map_(), segment_list_(), section_list_(),
- unattached_section_list_(), sections_are_attached_(false),
- special_output_list_(), section_headers_(NULL), tls_segment_(NULL),
- symtab_section_(NULL), dynsym_section_(NULL), dynamic_section_(NULL),
- dynamic_data_(NULL), eh_frame_section_(NULL), eh_frame_data_(NULL),
- added_eh_frame_data_(false), eh_frame_hdr_section_(NULL),
- build_id_note_(NULL), group_signatures_(), output_file_size_(-1),
+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_(),
+ dynpool_(),
+ signatures_(),
+ section_name_map_(),
+ segment_list_(),
+ section_list_(),
+ unattached_section_list_(),
+ special_output_list_(),
+ section_headers_(NULL),
+ tls_segment_(NULL),
+ relro_segment_(NULL),
+ symtab_section_(NULL),
+ symtab_xindex_(NULL),
+ dynsym_section_(NULL),
+ dynsym_xindex_(NULL),
+ dynamic_section_(NULL),
+ dynamic_data_(NULL),
+ eh_frame_section_(NULL),
+ eh_frame_data_(NULL),
+ added_eh_frame_data_(false),
+ eh_frame_hdr_section_(NULL),
+ build_id_note_(NULL),
+ debug_abbrev_(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)
{
// 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 k.first + k.second.first + k.second.second;
}
-// Return whether PREFIX is a prefix of STR.
-
-static inline bool
-is_prefix_of(const char* prefix, const char* str)
-{
- return strncmp(prefix, str, strlen(prefix)) == 0;
-}
-
// Returns whether the given section is in the list of
// debug-sections-used-by-some-version-of-gdb. Currently,
// we've checked versions of gdb up to and including 6.7.1.
".debug_str",
};
+static const char* lines_only_debug_sections[] =
+{ ".debug_abbrev",
+ // ".debug_aranges", // not used by gdb as of 6.7.1
+ // ".debug_frame",
+ ".debug_info",
+ ".debug_line",
+ // ".debug_loc",
+ // ".debug_macinfo",
+ // ".debug_pubnames", // not used by gdb as of 6.7.1
+ // ".debug_ranges",
+ ".debug_str",
+};
+
static inline bool
is_gdb_debug_section(const char* str)
{
return false;
}
+static inline bool
+is_lines_only_debug_section(const char* str)
+{
+ // We can do this faster: binary search or a hashtable. But why bother?
+ for (size_t i = 0;
+ i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
+ ++i)
+ if (strcmp(str, lines_only_debug_sections[i]) == 0)
+ return true;
+ return false;
+}
+
// Whether to include this section in the link.
template<int size, bool big_endian>
Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
const elfcpp::Shdr<size, big_endian>& shdr)
{
+ if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
+ return false;
+
switch (shdr.get_sh_type())
{
case elfcpp::SHT_NULL:
case elfcpp::SHT_SYMTAB:
case elfcpp::SHT_DYNSYM:
- case elfcpp::SHT_STRTAB:
case elfcpp::SHT_HASH:
case elfcpp::SHT_DYNAMIC:
case elfcpp::SHT_SYMTAB_SHNDX:
return false;
+ case elfcpp::SHT_STRTAB:
+ // Discard the sections which have special meanings in the ELF
+ // ABI. Keep others (e.g., .stabstr). We could also do this by
+ // checking the sh_link fields of the appropriate sections.
+ return (strcmp(name, ".dynstr") != 0
+ && strcmp(name, ".strtab") != 0
+ && strcmp(name, ".shstrtab") != 0);
+
case elfcpp::SHT_RELA:
case elfcpp::SHT_REL:
case elfcpp::SHT_GROUP:
case elfcpp::SHT_PROGBITS:
if (parameters->options().strip_debug()
&& (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ if (is_debug_info_section(name))
+ return false;
+ }
+ if (parameters->options().strip_debug_non_line()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
{
// Debugging sections can only be recognized by name.
if (is_prefix_of(".debug", name)
- || is_prefix_of(".gnu.linkonce.wi.", name)
- || is_prefix_of(".line", name)
- || is_prefix_of(".stab", name))
+ && !is_lines_only_debug_section(name))
return false;
}
if (parameters->options().strip_debug_gdb()
&& !is_gdb_debug_section(name))
return false;
}
+ if (parameters->options().strip_lto_sections()
+ && !parameters->options().relocatable()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ // Ignore LTO sections containing intermediate code.
+ if (is_prefix_of(".gnu.lto_", name))
+ return false;
+ }
return true;
default:
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
// 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;
const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
unsigned int reloc_shndx, unsigned int, off_t* off)
{
+ *off = 0;
+
if (!this->include_section(object, name, shdr))
return NULL;
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<size, big_endian>& shdr,
- const elfcpp::Elf_Word* contents)
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes)
{
gold_assert(parameters->options().relocatable());
gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
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);
section_size_type entry_count =
convert_to_section_size_type(shdr.get_sh_size() / 4);
Output_section_data* posd =
- new Output_data_group<size, big_endian>(object, entry_count, contents);
+ new Output_data_group<size, big_endian>(object, entry_count, flags,
+ shndxes);
os->add_output_section_data(posd);
}
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,
return os;
}
-// Add POSD to an output section using NAME, TYPE, and FLAGS.
+// Add POSD to an output section using NAME, TYPE, and FLAGS. Return
+// the output section.
-void
+Output_section*
Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags,
Output_section_data* posd)
false);
if (os != NULL)
os->add_output_section_data(posd);
+ return os;
}
// Map section flags to segment flags.
// 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)
{
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);
- else
+ os = new Output_compressed_section(¶meters->options(), name, type,
+ flags);
+
+ else if ((flags & elfcpp::SHF_ALLOC) == 0
+ && parameters->options().strip_debug_non_line()
+ && strcmp(".debug_abbrev", name) == 0)
+ {
+ os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
+ name, type, flags);
+ if (this->debug_info_)
+ this->debug_info_->set_abbreviations(this->debug_abbrev_);
+ }
+ else if ((flags & elfcpp::SHF_ALLOC) == 0
+ && parameters->options().strip_debug_non_line()
+ && strcmp(".debug_info", name) == 0)
+ {
+ os = this->debug_info_ = new Output_reduced_debug_info_section(
+ name, type, flags);
+ if (this->debug_abbrev_)
+ this->debug_info_->set_abbreviations(this->debug_abbrev_);
+ }
+ else
os = new Output_section(name, type, flags);
+ parameters->target().new_output_section(os);
+
this->section_list_.push_back(os);
// The GNU linker by default sorts some sections by priority, so we
|| strcmp(name, ".fini_array") == 0))
os->set_may_sort_attached_input_sections();
+ // With -z relro, we have to recognize the special sections by name.
+ // There is no other way.
+ if (!this->script_options_->saw_sections_clause()
+ && parameters->options().relro()
+ && type == elfcpp::SHT_PROGBITS
+ && (flags & elfcpp::SHF_ALLOC) != 0
+ && (flags & elfcpp::SHF_WRITE) != 0)
+ {
+ if (strcmp(name, ".data.rel.ro") == 0)
+ os->set_is_relro();
+ else if (strcmp(name, ".data.rel.ro.local") == 0)
+ {
+ os->set_is_relro();
+ os->set_is_relro_local();
+ }
+ }
+
+ // 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.
// 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
- && ((*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);
+ break;
}
if (p == this->segment_list_.end())
{
Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
seg_flags);
+ if (os->is_large_data_section())
+ oseg->set_is_large_data_segment();
oseg->add_output_section(os, seg_flags);
}
if ((flags & elfcpp::SHF_TLS) != 0)
{
if (this->tls_segment_ == NULL)
- this->tls_segment_ = this->make_output_segment(elfcpp::PT_TLS,
- seg_flags);
+ this->make_output_segment(elfcpp::PT_TLS, seg_flags);
this->tls_segment_->add_output_section(os, seg_flags);
}
+
+ // If -z relro is in effect, and we see a relro section, we create a
+ // PT_GNU_RELRO segment. There can only be one such segment.
+ if (os->is_relro() && parameters->options().relro())
+ {
+ 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);
+ }
}
// Make an output section for a script.
}
}
+// 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::SHF_ALLOC
| elfcpp::SHF_WRITE),
false);
+ this->dynamic_section_->set_is_relro();
symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
{
if ((*p)->type() == elfcpp::PT_LOAD
&& ((*p)->flags() & elfcpp::PF_R) != 0
- && ((*p)->flags() & elfcpp::PF_W) == 0)
+ && (parameters->options().omagic()
+ || ((*p)->flags() & elfcpp::PF_W) == 0))
return *p;
}
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 (this->incremental_inputs_)
+ {
+ this->incremental_inputs_->finalize();
+ this->create_incremental_info_sections();
+ }
// If there is a SECTIONS clause, put all the input sections into
// the required order.
else
load_seg = this->find_first_load_seg();
- if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
+ if (parameters->options().oformat_enum()
+ != General_options::OBJECT_FORMAT_ELF)
load_seg = NULL;
gold_assert(phdr_seg == NULL || load_seg != NULL);
// Lay out the file header.
Output_file_header* file_header;
file_header = new Output_file_header(target, symtab, segment_headers,
- this->options_.entry());
+ parameters->options().entry());
if (load_seg != NULL)
load_seg->add_initial_output_data(file_header);
// sections.
off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
+ // Set the section indexes of all unallocated sections seen so far,
+ // in case any of them are somehow referenced by a symbol.
+ shndx = this->set_section_indexes(shndx);
+
// Create the symbol table sections.
- this->create_symtab_sections(input_objects, symtab, &off);
+ this->create_symtab_sections(input_objects, symtab, shndx, &off);
if (!parameters->doing_static_link())
this->assign_local_dynsym_offsets(input_objects);
// don't have to wait for the input sections.
off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
- // Now that all sections have been created, set the section indexes.
+ // Now that all sections have been created, set the section indexes
+ // for any sections which haven't been done yet.
shndx = this->set_section_indexes(shndx);
// Create the section table header.
- this->create_shdrs(&off);
+ this->create_shdrs(shstrtab_section, &off);
// If there are no sections which require postprocessing, we can
// handle the section names now, and avoid a resize later.
}
// 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);
+ if (os == NULL)
+ return NULL;
+
Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
- size / 8);
+ size / 8,
+ "** note header");
os->add_output_section_data(posd);
*trailing_padding = aligned_descsz - descsz;
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);
if (trailing_padding > 0)
{
- posd = new Output_data_fixed_space(trailing_padding, 0);
+ posd = new Output_data_zero_fill(trailing_padding, 0);
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;
}
char buffer[uuidsz];
memset(buffer, 0, uuidsz);
- int descriptor = ::open("/dev/urandom", O_RDONLY);
+ int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
if (descriptor < 0)
gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
strerror(errno));
else
{
ssize_t got = ::read(descriptor, buffer, uuidsz);
- ::close(descriptor);
+ release_descriptor(descriptor, true);
if (got < 0)
gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
else if (static_cast<size_t>(got) != uuidsz)
// 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())
{
if (trailing_padding != 0)
{
- posd = new Output_data_fixed_space(trailing_padding, 0);
+ posd = new Output_data_zero_fill(trailing_padding, 0);
os->add_output_section_data(posd);
}
}
// We need to compute a checksum after we have completed the
// link.
gold_assert(trailing_padding == 0);
- this->build_id_note_ = new Output_data_fixed_space(descsz, 4);
+ 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);
+ 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);
+ 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.
if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
return false;
- // We put the PT_TLS segment last, because that is where the dynamic
- // linker expects to find it (this is just for efficiency; other
- // positions would also work correctly).
- if (type1 == elfcpp::PT_TLS && type2 != elfcpp::PT_TLS)
+ // We put the PT_TLS segment last except for the PT_GNU_RELRO
+ // segment, because that is where the dynamic linker expects to find
+ // it (this is just for efficiency; other positions would also work
+ // correctly).
+ if (type1 == elfcpp::PT_TLS
+ && type2 != elfcpp::PT_TLS
+ && type2 != elfcpp::PT_GNU_RELRO)
return false;
- if (type2 == elfcpp::PT_TLS && type1 != elfcpp::PT_TLS)
+ if (type2 == elfcpp::PT_TLS
+ && type1 != elfcpp::PT_TLS
+ && type1 != elfcpp::PT_GNU_RELRO)
+ return true;
+
+ // We put the PT_GNU_RELRO segment last, because that is where the
+ // dynamic linker expects to find it (as with PT_TLS, this is just
+ // for efficiency).
+ if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
+ return false;
+ if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
return true;
const elfcpp::Elf_Word flags1 = seg1->flags();
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();
+ if (parameters->options().user_set_Ttext())
+ addr = parameters->options().Ttext();
else if (parameters->options().shared())
addr = 0;
else
}
}
+ 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();
// 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;
}
uint64_t aligned_addr = 0;
uint64_t abi_pagesize = target->abi_pagesize();
+ uint64_t common_pagesize = target->common_pagesize();
- // FIXME: This should depend on the -n and -N options.
- (*p)->set_minimum_p_align(target->common_pagesize());
+ if (!parameters->options().nmagic()
+ && !parameters->options().omagic())
+ (*p)->set_minimum_p_align(common_pagesize);
- if (are_addresses_set)
- {
- // 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);
+
unsigned int shndx_hold = *pshndx;
uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
&off, pshndx);
if (!are_addresses_set && aligned_addr != addr)
{
- uint64_t common_pagesize = target->common_pagesize();
uint64_t first_off = (common_pagesize
- (aligned_addr
& (common_pagesize - 1)));
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);
}
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)
+ {
+ gold_assert(last_load_segment->paddr() <= (*p)->paddr());
+ if (last_load_segment->paddr() + last_load_segment->memsz()
+ > (*p)->paddr())
+ {
+ unsigned long long lb1 = last_load_segment->paddr();
+ unsigned long long le1 = lb1 + last_load_segment->memsz();
+ unsigned long long lb2 = (*p)->paddr();
+ unsigned long long le2 = lb2 + (*p)->memsz();
+ gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
+ "[0x%llx -> 0x%llx]"),
+ lb1, le1, lb2, le2);
+ }
+ }
+ last_load_segment = *p;
}
}
unsigned int
Layout::set_section_indexes(unsigned int shndx)
{
- const bool output_is_object = parameters->options().relocatable();
for (Section_list::iterator p = this->unattached_section_list_.begin();
p != this->unattached_section_list_.end();
++p)
{
- // In a relocatable link, we already did group sections.
- if (output_is_object
- && (*p)->type() == elfcpp::SHT_GROUP)
- continue;
-
- (*p)->set_out_shndx(shndx);
- ++shndx;
+ if (!(*p)->has_out_shndx())
+ {
+ (*p)->set_out_shndx(shndx);
+ ++shndx;
+ }
}
return shndx;
}
// Create the symbol table sections. Here we also set the final
// values of the symbols. At this point all the loadable sections are
-// fully laid out.
+// fully laid out. SHNUM is the number of sections so far.
void
Layout::create_symtab_sections(const Input_objects* input_objects,
Symbol_table* symtab,
+ unsigned int shnum,
off_t* poff)
{
int symsize;
++p)
{
unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
- off);
+ off, symtab);
off += (index - local_symbol_index) * symsize;
local_symbol_index = index;
}
this->symtab_section_ = osymtab;
Output_section_data* pos = new Output_data_fixed_space(off - startoff,
- align);
+ align,
+ "** symtab");
osymtab->add_output_section_data(pos);
+ // We generate a .symtab_shndx section if we have more than
+ // SHN_LORESERVE sections. Technically it is possible that we
+ // don't need one, because it is possible that there are no
+ // symbols in any of sections with indexes larger than
+ // SHN_LORESERVE. That is probably unusual, though, and it is
+ // easier to always create one than to compute section indexes
+ // twice (once here, once when writing out the symbols).
+ if (shnum >= elfcpp::SHN_LORESERVE)
+ {
+ const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
+ false, NULL);
+ Output_section* osymtab_xindex =
+ this->make_output_section(symtab_xindex_name,
+ elfcpp::SHT_SYMTAB_SHNDX, 0);
+
+ size_t symcount = (off - startoff) / symsize;
+ this->symtab_xindex_ = new Output_symtab_xindex(symcount);
+
+ osymtab_xindex->add_output_section_data(this->symtab_xindex_);
+
+ osymtab_xindex->set_link_section(osymtab);
+ osymtab_xindex->set_addralign(4);
+ osymtab_xindex->set_entsize(4);
+
+ osymtab_xindex->set_after_input_sections();
+
+ // This tells the driver code to wait until the symbol table
+ // has written out before writing out the postprocessing
+ // sections, including the .symtab_shndx section.
+ this->any_postprocessing_sections_ = true;
+ }
+
const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
Output_section* ostrtab = this->make_output_section(strtab_name,
elfcpp::SHT_STRTAB,
// offset.
void
-Layout::create_shdrs(off_t* poff)
+Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
{
Output_section_headers* oshdrs;
oshdrs = new Output_section_headers(this,
&this->segment_list_,
&this->section_list_,
&this->unattached_section_list_,
- &this->namepool_);
+ &this->namepool_,
+ shstrtab_section);
off_t off = align_address(*poff, oshdrs->addralign());
oshdrs->set_address_and_file_offset(0, off);
off += oshdrs->data_size();
this->section_headers_ = oshdrs;
}
+// Count the allocated sections.
+
+size_t
+Layout::allocated_output_section_count() const
+{
+ size_t section_count = 0;
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ section_count += (*p)->output_section_count();
+ return section_count;
+}
+
// Create the dynamic symbol table.
void
unsigned int local_symcount = index;
*plocal_dynamic_count = local_symcount;
- // FIXME: We have to tell set_dynsym_indexes whether the
- // -E/--export-dynamic option was used.
index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
&this->dynpool_, pversions);
false);
Output_section_data* odata = new Output_data_fixed_space(index * symsize,
- align);
+ align,
+ "** dynsym");
dynsym->add_output_section_data(odata);
dynsym->set_info(local_symcount);
odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
odyn->add_constant(elfcpp::DT_SYMENT, symsize);
+ // If there are more than SHN_LORESERVE allocated sections, we
+ // create a .dynsym_shndx section. It is possible that we don't
+ // need one, because it is possible that there are no dynamic
+ // symbols in any of the sections with indexes larger than
+ // SHN_LORESERVE. This is probably unusual, though, and at this
+ // time we don't know the actual section indexes so it is
+ // inconvenient to check.
+ if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
+ {
+ Output_section* dynsym_xindex =
+ this->choose_output_section(NULL, ".dynsym_shndx",
+ elfcpp::SHT_SYMTAB_SHNDX,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ this->dynsym_xindex_ = new Output_symtab_xindex(index);
+
+ dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
+
+ dynsym_xindex->set_link_section(dynsym);
+ dynsym_xindex->set_addralign(4);
+ dynsym_xindex->set_entsize(4);
+
+ dynsym_xindex->set_after_input_sections();
+
+ // This tells the driver code to wait until the symbol table has
+ // written out before writing out the postprocessing sections,
+ // including the .dynsym_shndx section.
+ this->any_postprocessing_sections_ = true;
+ }
+
// Create the dynamic string table section.
Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
- align);
+ align,
+ "** hash");
hashsec->add_output_section_data(hashdata);
hashsec->set_link_section(dynsym);
Output_section_data* hashdata = new Output_data_const_buffer(phash,
hashlen,
- align);
+ align,
+ "** hash");
hashsec->add_output_section_data(hashdata);
hashsec->set_link_section(dynsym);
dynamic_symbols,
&vbuf, &vsize);
- Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2);
+ Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
+ "** versions");
vsec->add_output_section_data(vdata);
vsec->set_entsize(2);
versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
&vdsize, &vdentries);
- Output_section_data* vddata = new Output_data_const_buffer(vdbuf,
- vdsize,
- 4);
+ Output_section_data* vddata =
+ new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
vdsec->add_output_section_data(vddata);
vdsec->set_link_section(dynstr);
&vnbuf, &vnsize,
&vnentries);
- Output_section_data* vndata = new Output_data_const_buffer(vnbuf,
- vnsize,
- 4);
+ Output_section_data* vndata =
+ new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
vnsec->add_output_section_data(vndata);
vnsec->set_link_section(dynstr);
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_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
elfcpp::PF_R);
- oseg->add_initial_output_section(osec, elfcpp::PF_R);
+ oseg->add_output_section(osec, elfcpp::PF_R);
}
}
Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
(elfcpp::PF_R
| elfcpp::PF_W));
- oseg->add_initial_output_section(this->dynamic_section_,
- elfcpp::PF_R | elfcpp::PF_W);
+ oseg->add_output_section(this->dynamic_section_,
+ elfcpp::PF_R | elfcpp::PF_W);
}
Output_data_dynamic* const odyn = this->dynamic_data_;
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 DT_INIT_ARRAY and DT_FINI_ARRAY.
// 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;
}
odyn->add_string(elfcpp::DT_RPATH, rpath_val);
+ if (parameters->options().enable_new_dtags())
+ odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
}
// Look for text segments that have dynamic relocations.
}
if (parameters->options().shared() && this->has_static_tls())
flags |= elfcpp::DF_STATIC_TLS;
+ if (parameters->options().origin())
+ flags |= elfcpp::DF_ORIGIN;
+ if (parameters->options().now())
+ flags |= elfcpp::DF_BIND_NOW;
odyn->add_constant(elfcpp::DT_FLAGS, flags);
-}
-// The mapping of .gnu.linkonce section names to real section names.
+ flags = 0;
+ if (parameters->options().initfirst())
+ flags |= elfcpp::DF_1_INITFIRST;
+ if (parameters->options().interpose())
+ flags |= elfcpp::DF_1_INTERPOSE;
+ if (parameters->options().loadfltr())
+ flags |= elfcpp::DF_1_LOADFLTR;
+ if (parameters->options().nodefaultlib())
+ flags |= elfcpp::DF_1_NODEFLIB;
+ if (parameters->options().nodelete())
+ flags |= elfcpp::DF_1_NODELETE;
+ if (parameters->options().nodlopen())
+ flags |= elfcpp::DF_1_NOOPEN;
+ if (parameters->options().nodump())
+ flags |= elfcpp::DF_1_NODUMP;
+ if (!parameters->options().shared())
+ flags &= ~(elfcpp::DF_1_INITFIRST
+ | elfcpp::DF_1_NODELETE
+ | 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 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", ".data.rel.ro"), // Must be 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" 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 = ".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(const char* signature, bool group)
-{
- std::string sig(signature);
- std::pair<Signatures::iterator, bool> ins(
- this->signatures_.insert(std::make_pair(sig, 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)
+{
+ // 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)
+ // 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
+ && parameters->options().plugins()->in_replacement_phase())
+ {
+ 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 = true;
+ ins.first->second.set_is_group_name();
return false;
}
else
gold_assert(!parameters->options().relocatable());
Output_segment* oseg = new Output_segment(type, flags);
this->segment_list_.push_back(oseg);
+
+ if (type == elfcpp::PT_TLS)
+ this->tls_segment_ = oseg;
+ else if (type == elfcpp::PT_GNU_RELRO)
+ this->relro_segment_ = oseg;
+
return oseg;
}
gold_assert(index > 0 && index != -1U);
off_t off = (symtab_section->offset()
+ index * symtab_section->entsize());
- symtab->write_section_symbol(*p, of, off);
+ symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
}
}
}
gold_assert(index > 0 && index != -1U);
off_t off = (dynsym_section->offset()
+ index * dynsym_section->entsize());
- symtab->write_section_symbol(*p, of, off);
+ symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
}
}
{
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.
out.close();
}
+// Print the output sections to the map file.
+
+void
+Layout::print_to_mapfile(Mapfile* mapfile) const
+{
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ (*p)->print_sections_to_mapfile(mapfile);
+}
+
// Print statistical information to stderr. This is used for --stats.
void
void
Write_symbols_task::run(Workqueue*)
{
- this->symtab_->write_globals(this->input_objects_, this->sympool_,
- this->dynpool_, this->of_);
+ this->symtab_->write_globals(this->sympool_, this->dynpool_,
+ this->layout_->symtab_xindex(),
+ this->layout_->dynsym_xindex(), this->of_);
}
// Write_after_input_sections_task methods.
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<32, false>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_32_BIG
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<32, true>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_64_LITTLE
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<64, false>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_64_BIG
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<64, true>& shdr,
- const elfcpp::Elf_Word* contents);
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
#endif
#ifdef HAVE_TARGET_32_LITTLE
projects / binutils-gdb.git / blobdiff