#include "symtab.h"
#include "dynobj.h"
#include "ehframe.h"
+#include "compressed_output.h"
#include "layout.h"
namespace gold
// have been read.
void
-Layout_task_runner::run(Workqueue* workqueue)
+Layout_task_runner::run(Workqueue* workqueue, const Task* task)
{
off_t file_size = this->layout_->finalize(this->input_objects_,
- this->symtab_);
+ this->symtab_,
+ task);
// Now we know the final size of the output file and we know where
// each piece of information goes.
: options_(options), namepool_(), sympool_(), dynpool_(), signatures_(),
section_name_map_(), segment_list_(), section_list_(),
unattached_section_list_(), special_output_list_(),
- tls_segment_(NULL), symtab_section_(NULL),
+ section_headers_(NULL), tls_segment_(NULL), symtab_section_(NULL),
dynsym_section_(NULL), dynamic_section_(NULL), dynamic_data_(NULL),
eh_frame_section_(NULL), output_file_size_(-1),
input_requires_executable_stack_(false),
input_with_gnu_stack_note_(false),
- input_without_gnu_stack_note_(false)
+ input_without_gnu_stack_note_(false),
+ has_static_tls_(false),
+ any_postprocessing_sections_(false)
{
// 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.
this->segment_list_.reserve(12);
- // We expect three unattached Output_data objects: the file header,
- // the segment headers, and the section headers.
- this->special_output_list_.reserve(3);
+ // We expect two unattached Output_data objects: the file header and
+ // the segment headers.
+ this->special_output_list_.reserve(2);
}
// Hash a key we use to look up an output section mapping.
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.
+
+static const char* gdb_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)
+{
+ // We can do this faster: binary search or a hashtable. But why bother?
+ for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
+ if (strcmp(str, gdb_sections[i]) == 0)
+ return true;
+ return false;
+}
+
// Whether to include this section in the link.
template<int size, bool big_endian>
|| is_prefix_of(".stab", name))
return false;
}
+ if (parameters->strip_debug_gdb()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ // Debugging sections can only be recognized by name.
+ if (is_prefix_of(".debug", name)
+ && !is_gdb_debug_section(name))
+ return false;
+ }
return true;
default:
// Canonicalize the section name.
Stringpool::Key name_key;
- name = this->namepool_.add_prefix(name, len, &name_key);
+ name = this->namepool_.add_with_length(name, len, true, &name_key);
// Find the output section. The output section is selected based on
// the section name, type, and flags.
return ret;
}
+// Sometimes we compress sections. This is typically done for
+// sections that are not part of normal program execution (such as
+// .debug_* sections), and where the readers of these sections know
+// how to deal with compressed sections. (To make it easier for them,
+// we will rename the ouput section in such cases from .foo to
+// .foo.zlib.nnnn, where nnnn is the uncompressed size.) This routine
+// doesn't say for certain whether we'll compress -- it depends on
+// commandline options as well -- just whether this section is a
+// candidate for compression.
+
+static bool
+is_compressible_debug_section(const char* secname)
+{
+ return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
+}
+
// Make a new Output_section, and attach it to segments as
// appropriate.
Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags)
{
- Output_section* os = new Output_section(name, type, flags);
+ Output_section* os;
+ if ((flags & elfcpp::SHF_ALLOC) == 0
+ && this->options_.compress_debug_sections()
+ && is_compressible_debug_section(name))
+ os = new Output_compressed_section(&this->options_, name, type, flags);
+ else
+ os = new Output_section(name, type, flags);
+
this->section_list_.push_back(os);
if ((flags & elfcpp::SHF_ALLOC) == 0)
// This function returns the size of the output file.
off_t
-Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
+Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
+ const Task* task)
{
Target* const target = input_objects->target();
target->finalize_sections(this);
+ this->count_local_symbols(task, input_objects);
+
this->create_gold_note();
this->create_executable_stack_info(target);
std::vector<Symbol*> dynamic_symbols;
unsigned int local_dynamic_count;
Versions versions;
- this->create_dynamic_symtab(target, symtab, &dynstr,
+ this->create_dynamic_symtab(input_objects, target, symtab, &dynstr,
&local_dynamic_count, &dynamic_symbols,
&versions);
this->special_output_list_.push_back(file_header);
// We set the output section indexes in set_segment_offsets and
- // set_section_offsets.
+ // set_section_indexes.
unsigned int shndx = 1;
// Set the file offsets of all the segments, and all the sections
// they contain.
off_t off = this->set_segment_offsets(target, load_seg, &shndx);
- // Set the file offsets of all the data sections not associated with
- // segments. This makes sure that debug sections have their offsets
- // before symbols are finalized.
- off = this->set_section_offsets(off, true);
-
// Create the symbol table sections.
- this->create_symtab_sections(input_objects, symtab, &off);
+ this->create_symtab_sections(input_objects, symtab, task, &off);
+ if (!parameters->doing_static_link())
+ this->assign_local_dynsym_offsets(input_objects);
// Create the .shstrtab section.
Output_section* shstrtab_section = this->create_shstrtab();
- // Set the file offsets of all the non-data sections not associated with
- // segments.
- off = this->set_section_offsets(off, false);
+ // Set the file offsets of all the non-data sections which 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.
shndx = this->set_section_indexes(shndx);
// Create the section table header.
- Output_section_headers* oshdrs = this->create_shdrs(&off);
+ this->create_shdrs(&off);
- file_header->set_section_info(oshdrs, shstrtab_section);
+ // If there are no sections which require postprocessing, we can
+ // handle the section names now, and avoid a resize later.
+ if (!this->any_postprocessing_sections_)
+ off = this->set_section_offsets(off,
+ STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
- // Now we know exactly where everything goes in the output file.
+ file_header->set_section_info(this->section_headers_, shstrtab_section);
+
+ // Now we know exactly where everything goes in the output file
+ // (except for non-allocated sections which require postprocessing).
Output_data::layout_complete();
this->output_file_size_ = off;
// Find the PT_LOAD segments, and set their addresses and offsets
// and their section's addresses and offsets.
uint64_t addr;
- if (options_.user_set_text_segment_address())
+ if (parameters->output_is_shared())
+ addr = 0;
+ else if (options_.user_set_text_segment_address())
addr = options_.text_segment_address();
else
addr = target->default_text_segment_address();
(*p)->set_offset();
}
+ // Set the TLS offsets for each section in the PT_TLS segment.
+ if (this->tls_segment_ != NULL)
+ this->tls_segment_->set_tls_offsets();
+
return off;
}
// segment.
off_t
-Layout::set_section_offsets(off_t off,
- bool do_bits_sections)
+Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
{
for (Section_list::iterator p = this->unattached_section_list_.begin();
p != this->unattached_section_list_.end();
++p)
{
- bool is_bits_section = ((*p)->type() == elfcpp::SHT_PROGBITS
- || (*p)->type() == elfcpp::SHT_NOBITS);
- if (is_bits_section != do_bits_sections)
- continue;
- if ((*p)->offset() != -1)
+ // The symtab section is handled in create_symtab_sections.
+ if (*p == this->symtab_section_)
continue;
+
+ if (pass == BEFORE_INPUT_SECTIONS_PASS
+ && (*p)->requires_postprocessing())
+ {
+ (*p)->create_postprocessing_buffer();
+ this->any_postprocessing_sections_ = true;
+ }
+
+ if (pass == BEFORE_INPUT_SECTIONS_PASS
+ && (*p)->after_input_sections())
+ continue;
+ else if (pass == POSTPROCESSING_SECTIONS_PASS
+ && (!(*p)->after_input_sections()
+ || (*p)->type() == elfcpp::SHT_STRTAB))
+ continue;
+ else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
+ && (!(*p)->after_input_sections()
+ || (*p)->type() != elfcpp::SHT_STRTAB))
+ continue;
+
off = align_address(off, (*p)->addralign());
- (*p)->set_address(0, off);
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
off += (*p)->data_size();
+
+ // At this point the name must be set.
+ if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
+ this->namepool_.add((*p)->name(), false, NULL);
}
return off;
}
return shndx;
}
+// Count the local symbols in the regular symbol table and the dynamic
+// symbol table, and build the respective string pools.
+
+void
+Layout::count_local_symbols(const Task* task,
+ const Input_objects* input_objects)
+{
+ // First, figure out an upper bound on the number of symbols we'll
+ // be inserting into each pool. This helps us create the pools with
+ // the right size, to avoid unnecessary hashtable resizing.
+ unsigned int symbol_count = 0;
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ symbol_count += (*p)->local_symbol_count();
+
+ // Go from "upper bound" to "estimate." We overcount for two
+ // reasons: we double-count symbols that occur in more than one
+ // object file, and we count symbols that are dropped from the
+ // output. Add it all together and assume we overcount by 100%.
+ symbol_count /= 2;
+
+ // We assume all symbols will go into both the sympool and dynpool.
+ this->sympool_.reserve(symbol_count);
+ this->dynpool_.reserve(symbol_count);
+
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ Task_lock_obj<Object> tlo(task, *p);
+ (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
+ }
+}
+
// 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.
void
Layout::create_symtab_sections(const Input_objects* input_objects,
Symbol_table* symtab,
+ const Task* task,
off_t* poff)
{
int symsize;
p != input_objects->relobj_end();
++p)
{
- Task_lock_obj<Object> tlo(**p);
unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
- off,
- &this->sympool_);
+ off);
off += (index - local_symbol_index) * symsize;
local_symbol_index = index;
}
== this->dynsym_section_->data_size() - locsize);
}
- off = symtab->finalize(local_symcount, off, dynoff, dyn_global_index,
+ off = symtab->finalize(task, local_symcount, off, dynoff, dyn_global_index,
dyncount, &this->sympool_);
if (!parameters->strip_all())
0);
this->symtab_section_ = osymtab;
- Output_section_data* pos = new Output_data_space(off - startoff,
- align);
+ Output_section_data* pos = new Output_data_fixed_space(off - startoff,
+ align);
osymtab->add_output_section_data(pos);
const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
ostrtab->add_output_section_data(pstr);
- osymtab->set_address(0, startoff);
+ osymtab->set_file_offset(startoff);
+ osymtab->finalize_data_size();
osymtab->set_link_section(ostrtab);
osymtab->set_info(local_symcount);
osymtab->set_entsize(symsize);
const char* name = this->namepool_.add(".shstrtab", false, NULL);
- this->namepool_.set_string_offsets();
-
Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0);
+ // We can't write out this section until we've set all the section
+ // names, and we don't set the names of compressed output sections
+ // until relocations are complete.
+ os->set_after_input_sections();
+
Output_section_data* posd = new Output_data_strtab(&this->namepool_);
os->add_output_section_data(posd);
// Create the section headers. SIZE is 32 or 64. OFF is the file
// offset.
-Output_section_headers*
+void
Layout::create_shdrs(off_t* poff)
{
Output_section_headers* oshdrs;
&this->unattached_section_list_,
&this->namepool_);
off_t off = align_address(*poff, oshdrs->addralign());
- oshdrs->set_address(0, off);
+ oshdrs->set_address_and_file_offset(0, off);
off += oshdrs->data_size();
*poff = off;
- this->special_output_list_.push_back(oshdrs);
- return oshdrs;
+ this->section_headers_ = oshdrs;
}
// Create the dynamic symbol table.
void
-Layout::create_dynamic_symtab(const Target* target, Symbol_table* symtab,
+Layout::create_dynamic_symtab(const Input_objects* input_objects,
+ const Target* target, Symbol_table* symtab,
Output_section **pdynstr,
unsigned int* plocal_dynamic_count,
std::vector<Symbol*>* pdynamic_symbols,
}
}
- // FIXME: Some targets apparently require local symbols in the
- // dynamic symbol table. Here is where we will have to count them,
- // and set the dynamic symbol indexes, and add the names to
- // this->dynpool_.
+ // Count the local symbols that need to go in the dynamic symbol table,
+ // and set the dynamic symbol indexes.
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
+ index = new_index;
+ }
unsigned int local_symcount = index;
*plocal_dynamic_count = local_symcount;
elfcpp::SHT_DYNSYM,
elfcpp::SHF_ALLOC);
- Output_section_data* odata = new Output_data_space(index * symsize,
- align);
+ Output_section_data* odata = new Output_data_fixed_space(index * symsize,
+ align);
dynsym->add_output_section_data(odata);
dynsym->set_info(local_symcount);
odyn->add_section_address(elfcpp::DT_HASH, hashsec);
}
+// Assign offsets to each local portion of the dynamic symbol table.
+
+void
+Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
+{
+ Output_section* dynsym = this->dynsym_section_;
+ gold_assert(dynsym != NULL);
+
+ off_t off = dynsym->offset();
+
+ // Skip the dummy symbol at the start of the section.
+ off += dynsym->entsize();
+
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ unsigned int count = (*p)->set_local_dynsym_offset(off);
+ off += count * dynsym->entsize();
+ }
+}
+
// Create the version sections.
void
odyn->add_string(elfcpp::DT_RPATH, rpath_val);
}
+
+ // Look for text segments that have dynamic relocations.
+ bool have_textrel = false;
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if (((*p)->flags() & elfcpp::PF_W) == 0
+ && (*p)->dynamic_reloc_count() > 0)
+ {
+ have_textrel = true;
+ break;
+ }
+ }
+
+ // Add a DT_FLAGS entry. We add it even if no flags are set so that
+ // post-link tools can easily modify these flags if desired.
+ unsigned int flags = 0;
+ if (have_textrel)
+ {
+ // Add a DT_TEXTREL for compatibility with older loaders.
+ odyn->add_constant(elfcpp::DT_TEXTREL, 0);
+ flags |= elfcpp::DF_TEXTREL;
+ }
+ if (parameters->output_is_shared() && this->has_static_tls())
+ flags |= elfcpp::DF_STATIC_TLS;
+ odyn->add_constant(elfcpp::DT_FLAGS, flags);
}
// The mapping of .gnu.linkonce section names to real section names.
// input sections are complete.
void
-Layout::write_sections_after_input_sections(Output_file* of) const
+Layout::write_sections_after_input_sections(Output_file* of)
{
+ // Determine the final section offsets, and thus the final output
+ // file size. Note we finalize the .shstrab last, to allow the
+ // after_input_section sections to modify their section-names before
+ // writing.
+ if (this->any_postprocessing_sections_)
+ {
+ 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,
+ STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
+
+ if (off > this->output_file_size_)
+ {
+ of->resize(off);
+ this->output_file_size_ = off;
+ }
+ }
+
for (Section_list::const_iterator p = this->section_list_.begin();
p != this->section_list_.end();
++p)
if ((*p)->after_input_sections())
(*p)->write(of);
}
+
+ this->section_headers_->write(of);
+}
+
+// Print statistical information to stderr. This is used for --stats.
+
+void
+Layout::print_stats() const
+{
+ this->namepool_.print_stats("section name pool");
+ this->sympool_.print_stats("output symbol name pool");
+ this->dynpool_.print_stats("dynamic name pool");
+
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ (*p)->print_merge_stats();
}
// Write_sections_task methods.
// We can always run this task.
-Task::Is_runnable_type
-Write_sections_task::is_runnable(Workqueue*)
+Task_token*
+Write_sections_task::is_runnable()
{
- return IS_RUNNABLE;
+ return NULL;
}
// We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
// when finished.
-class Write_sections_task::Write_sections_locker : public Task_locker
-{
- public:
- Write_sections_locker(Task_token& output_sections_blocker,
- Task_token& final_blocker,
- Workqueue* workqueue)
- : output_sections_block_(output_sections_blocker, workqueue),
- final_block_(final_blocker, workqueue)
- { }
-
- private:
- Task_block_token output_sections_block_;
- Task_block_token final_block_;
-};
-
-Task_locker*
-Write_sections_task::locks(Workqueue* workqueue)
+void
+Write_sections_task::locks(Task_locker* tl)
{
- return new Write_sections_locker(*this->output_sections_blocker_,
- *this->final_blocker_,
- workqueue);
+ tl->add(this, this->output_sections_blocker_);
+ tl->add(this, this->final_blocker_);
}
// Run the task--write out the data.
// We can always run this task.
-Task::Is_runnable_type
-Write_data_task::is_runnable(Workqueue*)
+Task_token*
+Write_data_task::is_runnable()
{
- return IS_RUNNABLE;
+ return NULL;
}
// We need to unlock FINAL_BLOCKER when finished.
-Task_locker*
-Write_data_task::locks(Workqueue* workqueue)
+void
+Write_data_task::locks(Task_locker* tl)
{
- return new Task_locker_block(*this->final_blocker_, workqueue);
+ tl->add(this, this->final_blocker_);
}
// Run the task--write out the data.
// We can always run this task.
-Task::Is_runnable_type
-Write_symbols_task::is_runnable(Workqueue*)
+Task_token*
+Write_symbols_task::is_runnable()
{
- return IS_RUNNABLE;
+ return NULL;
}
// We need to unlock FINAL_BLOCKER when finished.
-Task_locker*
-Write_symbols_task::locks(Workqueue* workqueue)
+void
+Write_symbols_task::locks(Task_locker* tl)
{
- return new Task_locker_block(*this->final_blocker_, workqueue);
+ tl->add(this, this->final_blocker_);
}
// Run the task--write out the symbols.
void
Write_symbols_task::run(Workqueue*)
{
- this->symtab_->write_globals(this->target_, this->sympool_, this->dynpool_,
- this->of_);
+ this->symtab_->write_globals(this->input_objects_, this->sympool_,
+ this->dynpool_, this->of_);
}
// Write_after_input_sections_task methods.
// We can only run this task after the input sections have completed.
-Task::Is_runnable_type
-Write_after_input_sections_task::is_runnable(Workqueue*)
+Task_token*
+Write_after_input_sections_task::is_runnable()
{
if (this->input_sections_blocker_->is_blocked())
- return IS_BLOCKED;
- return IS_RUNNABLE;
+ return this->input_sections_blocker_;
+ return NULL;
}
// We need to unlock FINAL_BLOCKER when finished.
-Task_locker*
-Write_after_input_sections_task::locks(Workqueue* workqueue)
+void
+Write_after_input_sections_task::locks(Task_locker* tl)
{
- return new Task_locker_block(*this->final_blocker_, workqueue);
+ tl->add(this, this->final_blocker_);
}
// Run the task.
// Run the task--close the file.
void
-Close_task_runner::run(Workqueue*)
+Close_task_runner::run(Workqueue*, const Task*)
{
this->of_->close();
}
projects / deliverable / binutils-gdb.git / blobdiff