X-Git-Url: https://oss.titaniummirror.com/gitweb?p=msp430-binutils.git;a=blobdiff_plain;f=gold%2Freloc.cc;fp=gold%2Freloc.cc;h=3018dc3daf5f497c6c7358ad95bc841a631a0ffe;hp=0000000000000000000000000000000000000000;hb=88750007d7869f178f0ba528f41efd3b74c424cf;hpb=6df9443a374e2b81278c61b8afc0a1eef7db280b diff --git a/gold/reloc.cc b/gold/reloc.cc new file mode 100644 index 0000000..3018dc3 --- /dev/null +++ b/gold/reloc.cc @@ -0,0 +1,1579 @@ +// reloc.cc -- relocate input files for gold. + +// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Written by Ian Lance Taylor . + +// This file is part of gold. + +// This program is free software; you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation; either version 3 of the License, or +// (at your option) any later version. + +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License +// along with this program; if not, write to the Free Software +// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, +// MA 02110-1301, USA. + +#include "gold.h" + +#include + +#include "workqueue.h" +#include "symtab.h" +#include "output.h" +#include "merge.h" +#include "object.h" +#include "target-reloc.h" +#include "reloc.h" +#include "icf.h" + +namespace gold +{ + +// Read_relocs methods. + +// These tasks just read the relocation information from the file. +// After reading it, the start another task to process the +// information. These tasks requires access to the file. + +Task_token* +Read_relocs::is_runnable() +{ + return this->object_->is_locked() ? this->object_->token() : NULL; +} + +// Lock the file. + +void +Read_relocs::locks(Task_locker* tl) +{ + tl->add(this, this->object_->token()); +} + +// Read the relocations and then start a Scan_relocs_task. + +void +Read_relocs::run(Workqueue* workqueue) +{ + Read_relocs_data *rd = new Read_relocs_data; + this->object_->read_relocs(rd); + this->object_->set_relocs_data(rd); + this->object_->release(); + + // If garbage collection or identical comdat folding is desired, we + // process the relocs first before scanning them. Scanning of relocs is + // done only after garbage or identical sections is identified. + if (parameters->options().gc_sections() + || parameters->options().icf_enabled()) + { + workqueue->queue_next(new Gc_process_relocs(this->options_, + this->symtab_, + this->layout_, + this->object_, rd, + this->symtab_lock_, + this->blocker_)); + } + else + { + workqueue->queue_next(new Scan_relocs(this->options_, this->symtab_, + this->layout_, this->object_, rd, + this->symtab_lock_, + this->blocker_)); + } +} + +// Return a debugging name for the task. + +std::string +Read_relocs::get_name() const +{ + return "Read_relocs " + this->object_->name(); +} + +// Gc_process_relocs methods. + +// These tasks process the relocations read by Read_relocs and +// determine which sections are referenced and which are garbage. +// This task is done only when --gc-sections is used. + +Task_token* +Gc_process_relocs::is_runnable() +{ + if (this->object_->is_locked()) + return this->object_->token(); + return NULL; +} + +void +Gc_process_relocs::locks(Task_locker* tl) +{ + tl->add(this, this->object_->token()); + tl->add(this, this->blocker_); +} + +void +Gc_process_relocs::run(Workqueue*) +{ + this->object_->gc_process_relocs(this->options_, this->symtab_, this->layout_, + this->rd_); + this->object_->release(); +} + +// Return a debugging name for the task. + +std::string +Gc_process_relocs::get_name() const +{ + return "Gc_process_relocs " + this->object_->name(); +} + +// Scan_relocs methods. + +// These tasks scan the relocations read by Read_relocs and mark up +// the symbol table to indicate which relocations are required. We +// use a lock on the symbol table to keep them from interfering with +// each other. + +Task_token* +Scan_relocs::is_runnable() +{ + if (!this->symtab_lock_->is_writable()) + return this->symtab_lock_; + if (this->object_->is_locked()) + return this->object_->token(); + return NULL; +} + +// Return the locks we hold: one on the file, one on the symbol table +// and one blocker. + +void +Scan_relocs::locks(Task_locker* tl) +{ + tl->add(this, this->object_->token()); + tl->add(this, this->symtab_lock_); + tl->add(this, this->blocker_); +} + +// Scan the relocs. + +void +Scan_relocs::run(Workqueue*) +{ + this->object_->scan_relocs(this->options_, this->symtab_, this->layout_, + this->rd_); + this->object_->release(); + delete this->rd_; + this->rd_ = NULL; +} + +// Return a debugging name for the task. + +std::string +Scan_relocs::get_name() const +{ + return "Scan_relocs " + this->object_->name(); +} + +// Relocate_task methods. + +// We may have to wait for the output sections to be written. + +Task_token* +Relocate_task::is_runnable() +{ + if (this->object_->relocs_must_follow_section_writes() + && this->output_sections_blocker_->is_blocked()) + return this->output_sections_blocker_; + + if (this->object_->is_locked()) + return this->object_->token(); + + return NULL; +} + +// We want to lock the file while we run. We want to unblock +// INPUT_SECTIONS_BLOCKER and FINAL_BLOCKER when we are done. +// INPUT_SECTIONS_BLOCKER may be NULL. + +void +Relocate_task::locks(Task_locker* tl) +{ + if (this->input_sections_blocker_ != NULL) + tl->add(this, this->input_sections_blocker_); + tl->add(this, this->final_blocker_); + tl->add(this, this->object_->token()); +} + +// Run the task. + +void +Relocate_task::run(Workqueue*) +{ + this->object_->relocate(this->options_, this->symtab_, this->layout_, + this->of_); + + // This is normally the last thing we will do with an object, so + // uncache all views. + this->object_->clear_view_cache_marks(); + + this->object_->release(); +} + +// Return a debugging name for the task. + +std::string +Relocate_task::get_name() const +{ + return "Relocate_task " + this->object_->name(); +} + +// Read the relocs and local symbols from the object file and store +// the information in RD. + +template +void +Sized_relobj::do_read_relocs(Read_relocs_data* rd) +{ + rd->relocs.clear(); + + unsigned int shnum = this->shnum(); + if (shnum == 0) + return; + + rd->relocs.reserve(shnum / 2); + + const Output_sections& out_sections(this->output_sections()); + const std::vector
& out_offsets(this->section_offsets_); + + const unsigned char *pshdrs = this->get_view(this->elf_file_.shoff(), + shnum * This::shdr_size, + true, true); + // Skip the first, dummy, section. + const unsigned char *ps = pshdrs + This::shdr_size; + for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size) + { + typename This::Shdr shdr(ps); + + unsigned int sh_type = shdr.get_sh_type(); + if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA) + continue; + + unsigned int shndx = this->adjust_shndx(shdr.get_sh_info()); + if (shndx >= shnum) + { + this->error(_("relocation section %u has bad info %u"), + i, shndx); + continue; + } + + Output_section* os = out_sections[shndx]; + if (os == NULL) + continue; + + // We are scanning relocations in order to fill out the GOT and + // PLT sections. Relocations for sections which are not + // allocated (typically debugging sections) should not add new + // GOT and PLT entries. So we skip them unless this is a + // relocatable link or we need to emit relocations. FIXME: What + // should we do if a linker script maps a section with SHF_ALLOC + // clear to a section with SHF_ALLOC set? + typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size); + bool is_section_allocated = ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC) + != 0); + if (!is_section_allocated + && !parameters->options().relocatable() + && !parameters->options().emit_relocs()) + continue; + + if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_) + { + this->error(_("relocation section %u uses unexpected " + "symbol table %u"), + i, this->adjust_shndx(shdr.get_sh_link())); + continue; + } + + off_t sh_size = shdr.get_sh_size(); + + unsigned int reloc_size; + if (sh_type == elfcpp::SHT_REL) + reloc_size = elfcpp::Elf_sizes::rel_size; + else + reloc_size = elfcpp::Elf_sizes::rela_size; + if (reloc_size != shdr.get_sh_entsize()) + { + this->error(_("unexpected entsize for reloc section %u: %lu != %u"), + i, static_cast(shdr.get_sh_entsize()), + reloc_size); + continue; + } + + size_t reloc_count = sh_size / reloc_size; + if (static_cast(reloc_count * reloc_size) != sh_size) + { + this->error(_("reloc section %u size %lu uneven"), + i, static_cast(sh_size)); + continue; + } + + rd->relocs.push_back(Section_relocs()); + Section_relocs& sr(rd->relocs.back()); + sr.reloc_shndx = i; + sr.data_shndx = shndx; + sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size, + true, true); + sr.sh_type = sh_type; + sr.reloc_count = reloc_count; + sr.output_section = os; + sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address; + sr.is_data_section_allocated = is_section_allocated; + } + + // Read the local symbols. + gold_assert(this->symtab_shndx_ != -1U); + if (this->symtab_shndx_ == 0 || this->local_symbol_count_ == 0) + rd->local_symbols = NULL; + else + { + typename This::Shdr symtabshdr(pshdrs + + this->symtab_shndx_ * This::shdr_size); + gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); + const int sym_size = This::sym_size; + const unsigned int loccount = this->local_symbol_count_; + gold_assert(loccount == symtabshdr.get_sh_info()); + off_t locsize = loccount * sym_size; + rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(), + locsize, true, true); + } +} + +// Process the relocs to generate mappings from source sections to referenced +// sections. This is used during garbage colletion to determine garbage +// sections. + +template +void +Sized_relobj::do_gc_process_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd) +{ + Sized_target* target = + parameters->sized_target(); + + const unsigned char* local_symbols; + if (rd->local_symbols == NULL) + local_symbols = NULL; + else + local_symbols = rd->local_symbols->data(); + + for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin(); + p != rd->relocs.end(); + ++p) + { + if (!parameters->options().relocatable()) + { + // As noted above, when not generating an object file, we + // only scan allocated sections. We may see a non-allocated + // section here if we are emitting relocs. + if (p->is_data_section_allocated) + target->gc_process_relocs(options, symtab, layout, this, + p->data_shndx, p->sh_type, + p->contents->data(), p->reloc_count, + p->output_section, + p->needs_special_offset_handling, + this->local_symbol_count_, + local_symbols); + } + } +} + + +// Scan the relocs and adjust the symbol table. This looks for +// relocations which require GOT/PLT/COPY relocations. + +template +void +Sized_relobj::do_scan_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd) +{ + Sized_target* target = + parameters->sized_target(); + + const unsigned char* local_symbols; + if (rd->local_symbols == NULL) + local_symbols = NULL; + else + local_symbols = rd->local_symbols->data(); + + for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin(); + p != rd->relocs.end(); + ++p) + { + // When garbage collection is on, unreferenced sections are not included + // in the link that would have been included normally. This is known only + // after Read_relocs hence this check has to be done again. + if (parameters->options().gc_sections() + || parameters->options().icf_enabled()) + { + if (p->output_section == NULL) + continue; + } + if (!parameters->options().relocatable()) + { + // As noted above, when not generating an object file, we + // only scan allocated sections. We may see a non-allocated + // section here if we are emitting relocs. + if (p->is_data_section_allocated) + target->scan_relocs(options, symtab, layout, this, p->data_shndx, + p->sh_type, p->contents->data(), + p->reloc_count, p->output_section, + p->needs_special_offset_handling, + this->local_symbol_count_, + local_symbols); + if (parameters->options().emit_relocs()) + this->emit_relocs_scan(options, symtab, layout, local_symbols, p); + } + else + { + Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx); + gold_assert(rr != NULL); + rr->set_reloc_count(p->reloc_count); + target->scan_relocatable_relocs(options, symtab, layout, this, + p->data_shndx, p->sh_type, + p->contents->data(), + p->reloc_count, + p->output_section, + p->needs_special_offset_handling, + this->local_symbol_count_, + local_symbols, + rr); + } + + delete p->contents; + p->contents = NULL; + } + + if (rd->local_symbols != NULL) + { + delete rd->local_symbols; + rd->local_symbols = NULL; + } +} + +// This is a strategy class we use when scanning for --emit-relocs. + +template +class Emit_relocs_strategy +{ + public: + // A local non-section symbol. + inline Relocatable_relocs::Reloc_strategy + local_non_section_strategy(unsigned int, Relobj*, unsigned int) + { return Relocatable_relocs::RELOC_COPY; } + + // A local section symbol. + inline Relocatable_relocs::Reloc_strategy + local_section_strategy(unsigned int, Relobj*) + { + if (sh_type == elfcpp::SHT_RELA) + return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA; + else + { + // The addend is stored in the section contents. Since this + // is not a relocatable link, we are going to apply the + // relocation contents to the section as usual. This means + // that we have no way to record the original addend. If the + // original addend is not zero, there is basically no way for + // the user to handle this correctly. Caveat emptor. + return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0; + } + } + + // A global symbol. + inline Relocatable_relocs::Reloc_strategy + global_strategy(unsigned int, Relobj*, unsigned int) + { return Relocatable_relocs::RELOC_COPY; } +}; + +// Scan the input relocations for --emit-relocs. + +template +void +Sized_relobj::emit_relocs_scan( + const General_options& options, + Symbol_table* symtab, + Layout* layout, + const unsigned char* plocal_syms, + const Read_relocs_data::Relocs_list::iterator& p) +{ + Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx); + gold_assert(rr != NULL); + rr->set_reloc_count(p->reloc_count); + + if (p->sh_type == elfcpp::SHT_REL) + this->emit_relocs_scan_reltype(options, symtab, layout, + plocal_syms, p, rr); + else + { + gold_assert(p->sh_type == elfcpp::SHT_RELA); + this->emit_relocs_scan_reltype(options, symtab, + layout, plocal_syms, p, + rr); + } +} + +// Scan the input relocation for --emit-relocs, templatized on the +// type of the relocation section. + +template +template +void +Sized_relobj::emit_relocs_scan_reltype( + const General_options& options, + Symbol_table* symtab, + Layout* layout, + const unsigned char* plocal_syms, + const Read_relocs_data::Relocs_list::iterator& p, + Relocatable_relocs* rr) +{ + scan_relocatable_relocs >( + options, + symtab, + layout, + this, + p->data_shndx, + p->contents->data(), + p->reloc_count, + p->output_section, + p->needs_special_offset_handling, + this->local_symbol_count_, + plocal_syms, + rr); +} + +// Relocate the input sections and write out the local symbols. + +template +void +Sized_relobj::do_relocate(const General_options& options, + const Symbol_table* symtab, + const Layout* layout, + Output_file* of) +{ + unsigned int shnum = this->shnum(); + + // Read the section headers. + const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(), + shnum * This::shdr_size, + true, true); + + Views views; + views.resize(shnum); + + // Make two passes over the sections. The first one copies the + // section data to the output file. The second one applies + // relocations. + + this->write_sections(pshdrs, of, &views); + + // To speed up relocations, we set up hash tables for fast lookup of + // input offsets to output addresses. + this->initialize_input_to_output_maps(); + + // Apply relocations. + + this->relocate_sections(options, symtab, layout, pshdrs, &views); + + // After we've done the relocations, we release the hash tables, + // since we no longer need them. + this->free_input_to_output_maps(); + + // Write out the accumulated views. + for (unsigned int i = 1; i < shnum; ++i) + { + if (views[i].view != NULL) + { + if (!views[i].is_postprocessing_view) + { + if (views[i].is_input_output_view) + of->write_input_output_view(views[i].offset, + views[i].view_size, + views[i].view); + else + of->write_output_view(views[i].offset, views[i].view_size, + views[i].view); + } + } + } + + // Write out the local symbols. + this->write_local_symbols(of, layout->sympool(), layout->dynpool(), + layout->symtab_xindex(), layout->dynsym_xindex()); + + // We should no longer need the local symbol values. + this->clear_local_symbols(); +} + +// Sort a Read_multiple vector by file offset. +struct Read_multiple_compare +{ + inline bool + operator()(const File_read::Read_multiple_entry& rme1, + const File_read::Read_multiple_entry& rme2) const + { return rme1.file_offset < rme2.file_offset; } +}; + +// Write section data to the output file. PSHDRS points to the +// section headers. Record the views in *PVIEWS for use when +// relocating. + +template +void +Sized_relobj::write_sections(const unsigned char* pshdrs, + Output_file* of, + Views* pviews) +{ + unsigned int shnum = this->shnum(); + const Output_sections& out_sections(this->output_sections()); + const std::vector
& out_offsets(this->section_offsets_); + + File_read::Read_multiple rm; + bool is_sorted = true; + + const unsigned char* p = pshdrs + This::shdr_size; + for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size) + { + View_size* pvs = &(*pviews)[i]; + + pvs->view = NULL; + + const Output_section* os = out_sections[i]; + if (os == NULL) + continue; + Address output_offset = out_offsets[i]; + + typename This::Shdr shdr(p); + + if (shdr.get_sh_type() == elfcpp::SHT_NOBITS) + continue; + + if ((parameters->options().relocatable() + || parameters->options().emit_relocs()) + && (shdr.get_sh_type() == elfcpp::SHT_REL + || shdr.get_sh_type() == elfcpp::SHT_RELA) + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0) + { + // This is a reloc section in a relocatable link or when + // emitting relocs. We don't need to read the input file. + // The size and file offset are stored in the + // Relocatable_relocs structure. + Relocatable_relocs* rr = this->relocatable_relocs(i); + gold_assert(rr != NULL); + Output_data* posd = rr->output_data(); + gold_assert(posd != NULL); + + pvs->offset = posd->offset(); + pvs->view_size = posd->data_size(); + pvs->view = of->get_output_view(pvs->offset, pvs->view_size); + pvs->address = posd->address(); + pvs->is_input_output_view = false; + pvs->is_postprocessing_view = false; + + continue; + } + + // In the normal case, this input section is simply mapped to + // the output section at offset OUTPUT_OFFSET. + + // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is + // handled specially--e.g., a .eh_frame section. The relocation + // routines need to check for each reloc where it should be + // applied. For this case, we need an input/output view for the + // entire contents of the section in the output file. We don't + // want to copy the contents of the input section to the output + // section; the output section contents were already written, + // and we waited for them in Relocate_task::is_runnable because + // relocs_must_follow_section_writes is set for the object. + + // Regardless of which of the above cases is true, we have to + // check requires_postprocessing of the output section. If that + // is false, then we work with views of the output file + // directly. If it is true, then we work with a separate + // buffer, and the output section is responsible for writing the + // final data to the output file. + + off_t output_section_offset; + Address output_section_size; + if (!os->requires_postprocessing()) + { + output_section_offset = os->offset(); + output_section_size = convert_types(os->data_size()); + } + else + { + output_section_offset = 0; + output_section_size = + convert_types(os->postprocessing_buffer_size()); + } + + off_t view_start; + section_size_type view_size; + if (output_offset != invalid_address) + { + view_start = output_section_offset + output_offset; + view_size = convert_to_section_size_type(shdr.get_sh_size()); + } + else + { + view_start = output_section_offset; + view_size = convert_to_section_size_type(output_section_size); + } + + if (view_size == 0) + continue; + + gold_assert(output_offset == invalid_address + || output_offset + view_size <= output_section_size); + + unsigned char* view; + if (os->requires_postprocessing()) + { + unsigned char* buffer = os->postprocessing_buffer(); + view = buffer + view_start; + if (output_offset != invalid_address) + { + off_t sh_offset = shdr.get_sh_offset(); + if (!rm.empty() && rm.back().file_offset > sh_offset) + is_sorted = false; + rm.push_back(File_read::Read_multiple_entry(sh_offset, + view_size, view)); + } + } + else + { + if (output_offset == invalid_address) + view = of->get_input_output_view(view_start, view_size); + else + { + view = of->get_output_view(view_start, view_size); + off_t sh_offset = shdr.get_sh_offset(); + if (!rm.empty() && rm.back().file_offset > sh_offset) + is_sorted = false; + rm.push_back(File_read::Read_multiple_entry(sh_offset, + view_size, view)); + } + } + + pvs->view = view; + pvs->address = os->address(); + if (output_offset != invalid_address) + pvs->address += output_offset; + pvs->offset = view_start; + pvs->view_size = view_size; + pvs->is_input_output_view = output_offset == invalid_address; + pvs->is_postprocessing_view = os->requires_postprocessing(); + } + + // Actually read the data. + if (!rm.empty()) + { + if (!is_sorted) + std::sort(rm.begin(), rm.end(), Read_multiple_compare()); + this->read_multiple(rm); + } +} + +// Relocate section data. VIEWS points to the section data as views +// in the output file. + +template +void +Sized_relobj::relocate_sections( + const General_options& options, + const Symbol_table* symtab, + const Layout* layout, + const unsigned char* pshdrs, + Views* pviews) +{ + unsigned int shnum = this->shnum(); + Sized_target* target = + parameters->sized_target(); + + const Output_sections& out_sections(this->output_sections()); + const std::vector
& out_offsets(this->section_offsets_); + + Relocate_info relinfo; + relinfo.options = &options; + relinfo.symtab = symtab; + relinfo.layout = layout; + relinfo.object = this; + + const unsigned char* p = pshdrs + This::shdr_size; + for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size) + { + typename This::Shdr shdr(p); + + unsigned int sh_type = shdr.get_sh_type(); + if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA) + continue; + + off_t sh_size = shdr.get_sh_size(); + if (sh_size == 0) + continue; + + unsigned int index = this->adjust_shndx(shdr.get_sh_info()); + if (index >= this->shnum()) + { + this->error(_("relocation section %u has bad info %u"), + i, index); + continue; + } + + Output_section* os = out_sections[index]; + if (os == NULL) + { + // This relocation section is against a section which we + // discarded. + continue; + } + Address output_offset = out_offsets[index]; + + gold_assert((*pviews)[index].view != NULL); + if (parameters->options().relocatable()) + gold_assert((*pviews)[i].view != NULL); + + if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_) + { + gold_error(_("relocation section %u uses unexpected " + "symbol table %u"), + i, this->adjust_shndx(shdr.get_sh_link())); + continue; + } + + const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(), + sh_size, true, false); + + unsigned int reloc_size; + if (sh_type == elfcpp::SHT_REL) + reloc_size = elfcpp::Elf_sizes::rel_size; + else + reloc_size = elfcpp::Elf_sizes::rela_size; + + if (reloc_size != shdr.get_sh_entsize()) + { + gold_error(_("unexpected entsize for reloc section %u: %lu != %u"), + i, static_cast(shdr.get_sh_entsize()), + reloc_size); + continue; + } + + size_t reloc_count = sh_size / reloc_size; + if (static_cast(reloc_count * reloc_size) != sh_size) + { + gold_error(_("reloc section %u size %lu uneven"), + i, static_cast(sh_size)); + continue; + } + + gold_assert(output_offset != invalid_address + || this->relocs_must_follow_section_writes()); + + relinfo.reloc_shndx = i; + relinfo.reloc_shdr = p; + relinfo.data_shndx = index; + relinfo.data_shdr = pshdrs + index * This::shdr_size; + unsigned char* view = (*pviews)[index].view; + Address address = (*pviews)[index].address; + section_size_type view_size = (*pviews)[index].view_size; + + Reloc_symbol_changes* reloc_map = NULL; + if (this->uses_split_stack() && output_offset != invalid_address) + { + typename This::Shdr data_shdr(pshdrs + index * This::shdr_size); + if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0) + this->split_stack_adjust(symtab, pshdrs, sh_type, index, + prelocs, reloc_count, view, view_size, + &reloc_map); + } + + if (!parameters->options().relocatable()) + { + target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os, + output_offset == invalid_address, + view, address, view_size, reloc_map); + if (parameters->options().emit_relocs()) + this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count, + os, output_offset, view, address, view_size, + (*pviews)[i].view, (*pviews)[i].view_size); + } + else + { + Relocatable_relocs* rr = this->relocatable_relocs(i); + target->relocate_for_relocatable(&relinfo, sh_type, prelocs, + reloc_count, os, output_offset, rr, + view, address, view_size, + (*pviews)[i].view, + (*pviews)[i].view_size); + } + } +} + +// Emit the relocs for --emit-relocs. + +template +void +Sized_relobj::emit_relocs( + const Relocate_info* relinfo, + unsigned int i, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + typename elfcpp::Elf_types::Elf_Addr offset_in_output_section, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size, + unsigned char* reloc_view, + section_size_type reloc_view_size) +{ + if (sh_type == elfcpp::SHT_REL) + this->emit_relocs_reltype(relinfo, i, prelocs, + reloc_count, output_section, + offset_in_output_section, + view, address, view_size, + reloc_view, reloc_view_size); + else + { + gold_assert(sh_type == elfcpp::SHT_RELA); + this->emit_relocs_reltype(relinfo, i, prelocs, + reloc_count, output_section, + offset_in_output_section, + view, address, view_size, + reloc_view, reloc_view_size); + } +} + +// Emit the relocs for --emit-relocs, templatized on the type of the +// relocation section. + +template +template +void +Sized_relobj::emit_relocs_reltype( + const Relocate_info* relinfo, + unsigned int i, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + typename elfcpp::Elf_types::Elf_Addr offset_in_output_section, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size, + unsigned char* reloc_view, + section_size_type reloc_view_size) +{ + const Relocatable_relocs* rr = this->relocatable_relocs(i); + relocate_for_relocatable( + relinfo, + prelocs, + reloc_count, + output_section, + offset_in_output_section, + rr, + view, + address, + view_size, + reloc_view, + reloc_view_size); +} + +// Create merge hash tables for the local symbols. These are used to +// speed up relocations. + +template +void +Sized_relobj::initialize_input_to_output_maps() +{ + const unsigned int loccount = this->local_symbol_count_; + for (unsigned int i = 1; i < loccount; ++i) + { + Symbol_value& lv(this->local_values_[i]); + lv.initialize_input_to_output_map(this); + } +} + +// Free merge hash tables for the local symbols. + +template +void +Sized_relobj::free_input_to_output_maps() +{ + const unsigned int loccount = this->local_symbol_count_; + for (unsigned int i = 1; i < loccount; ++i) + { + Symbol_value& lv(this->local_values_[i]); + lv.free_input_to_output_map(); + } +} + +// If an object was compiled with -fsplit-stack, this is called to +// check whether any relocations refer to functions defined in objects +// which were not compiled with -fsplit-stack. If they were, then we +// need to apply some target-specific adjustments to request +// additional stack space. + +template +void +Sized_relobj::split_stack_adjust( + const Symbol_table* symtab, + const unsigned char* pshdrs, + unsigned int sh_type, + unsigned int shndx, + const unsigned char* prelocs, + size_t reloc_count, + unsigned char* view, + section_size_type view_size, + Reloc_symbol_changes** reloc_map) +{ + if (sh_type == elfcpp::SHT_REL) + this->split_stack_adjust_reltype(symtab, pshdrs, shndx, + prelocs, reloc_count, + view, view_size, + reloc_map); + else + { + gold_assert(sh_type == elfcpp::SHT_RELA); + this->split_stack_adjust_reltype(symtab, pshdrs, shndx, + prelocs, reloc_count, + view, view_size, + reloc_map); + } +} + +// Adjust for -fsplit-stack, templatized on the type of the relocation +// section. + +template +template +void +Sized_relobj::split_stack_adjust_reltype( + const Symbol_table* symtab, + const unsigned char* pshdrs, + unsigned int shndx, + const unsigned char* prelocs, + size_t reloc_count, + unsigned char* view, + section_size_type view_size, + Reloc_symbol_changes** reloc_map) +{ + typedef typename Reloc_types::Reloc Reltype; + const int reloc_size = Reloc_types::reloc_size; + + size_t local_count = this->local_symbol_count(); + + std::vector non_split_refs; + + const unsigned char* pr = prelocs; + for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size) + { + Reltype reloc(pr); + + typename elfcpp::Elf_types::Elf_WXword r_info = reloc.get_r_info(); + unsigned int r_sym = elfcpp::elf_r_sym(r_info); + if (r_sym < local_count) + continue; + + const Symbol* gsym = this->global_symbol(r_sym); + gold_assert(gsym != NULL); + if (gsym->is_forwarder()) + gsym = symtab->resolve_forwards(gsym); + + // See if this relocation refers to a function defined in an + // object compiled without -fsplit-stack. Note that we don't + // care about the type of relocation--this means that in some + // cases we will ask for a large stack unnecessarily, but this + // is not fatal. FIXME: Some targets have symbols which are + // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC. + if (gsym->type() == elfcpp::STT_FUNC + && !gsym->is_undefined() + && gsym->source() == Symbol::FROM_OBJECT + && !gsym->object()->uses_split_stack()) + { + section_offset_type offset = + convert_to_section_size_type(reloc.get_r_offset()); + non_split_refs.push_back(offset); + } + } + + if (non_split_refs.empty()) + return; + + // At this point, every entry in NON_SPLIT_REFS indicates a + // relocation which refers to a function in an object compiled + // without -fsplit-stack. We now have to convert that list into a + // set of offsets to functions. First, we find all the functions. + + Function_offsets function_offsets; + this->find_functions(pshdrs, shndx, &function_offsets); + if (function_offsets.empty()) + return; + + // Now get a list of the function with references to non split-stack + // code. + + Function_offsets calls_non_split; + for (std::vector::const_iterator p + = non_split_refs.begin(); + p != non_split_refs.end(); + ++p) + { + Function_offsets::const_iterator low = function_offsets.lower_bound(*p); + if (low == function_offsets.end()) + --low; + else if (low->first == *p) + ; + else if (low == function_offsets.begin()) + continue; + else + --low; + + calls_non_split.insert(*low); + } + if (calls_non_split.empty()) + return; + + // Now we have a set of functions to adjust. The adjustments are + // target specific. Besides changing the output section view + // however, it likes, the target may request a relocation change + // from one global symbol name to another. + + for (Function_offsets::const_iterator p = calls_non_split.begin(); + p != calls_non_split.end(); + ++p) + { + std::string from; + std::string to; + parameters->target().calls_non_split(this, shndx, p->first, p->second, + view, view_size, &from, &to); + if (!from.empty()) + { + gold_assert(!to.empty()); + Symbol* tosym = NULL; + + // Find relocations in the relevant function which are for + // FROM. + pr = prelocs; + for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size) + { + Reltype reloc(pr); + + typename elfcpp::Elf_types::Elf_WXword r_info = + reloc.get_r_info(); + unsigned int r_sym = elfcpp::elf_r_sym(r_info); + if (r_sym < local_count) + continue; + + section_offset_type offset = + convert_to_section_size_type(reloc.get_r_offset()); + if (offset < p->first + || (offset + >= (p->first + + static_cast(p->second)))) + continue; + + const Symbol* gsym = this->global_symbol(r_sym); + if (from == gsym->name()) + { + if (tosym == NULL) + { + tosym = symtab->lookup(to.c_str()); + if (tosym == NULL) + { + this->error(_("could not convert call " + "to '%s' to '%s'"), + from.c_str(), to.c_str()); + break; + } + } + + if (*reloc_map == NULL) + *reloc_map = new Reloc_symbol_changes(reloc_count); + (*reloc_map)->set(i, tosym); + } + } + } + } +} + +// Find all the function in this object defined in section SHNDX. +// Store their offsets in the section in FUNCTION_OFFSETS. + +template +void +Sized_relobj::find_functions( + const unsigned char* pshdrs, + unsigned int shndx, + Sized_relobj::Function_offsets* function_offsets) +{ + // We need to read the symbols to find the functions. If we wanted + // to, we could cache reading the symbols across all sections in the + // object. + const unsigned int symtab_shndx = this->symtab_shndx_; + typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size); + gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); + + typename elfcpp::Elf_types::Elf_WXword sh_size = + symtabshdr.get_sh_size(); + const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), + sh_size, true, true); + + const int sym_size = This::sym_size; + const unsigned int symcount = sh_size / sym_size; + for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size) + { + typename elfcpp::Sym isym(psyms); + + // FIXME: Some targets can have functions which do not have type + // STT_FUNC, e.g., STT_ARM_TFUNC. + if (isym.get_st_type() != elfcpp::STT_FUNC + || isym.get_st_size() == 0) + continue; + + bool is_ordinary; + unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(), + &is_ordinary); + if (!is_ordinary || sym_shndx != shndx) + continue; + + section_offset_type value = + convert_to_section_size_type(isym.get_st_value()); + section_size_type fnsize = + convert_to_section_size_type(isym.get_st_size()); + + (*function_offsets)[value] = fnsize; + } +} + +// Class Merged_symbol_value. + +template +void +Merged_symbol_value::initialize_input_to_output_map( + const Relobj* object, + unsigned int input_shndx) +{ + Object_merge_map* map = object->merge_map(); + map->initialize_input_to_output_map(input_shndx, + this->output_start_address_, + &this->output_addresses_); +} + +// Get the output value corresponding to an input offset if we +// couldn't find it in the hash table. + +template +typename elfcpp::Elf_types::Elf_Addr +Merged_symbol_value::value_from_output_section( + const Relobj* object, + unsigned int input_shndx, + typename elfcpp::Elf_types::Elf_Addr input_offset) const +{ + section_offset_type output_offset; + bool found = object->merge_map()->get_output_offset(NULL, input_shndx, + input_offset, + &output_offset); + + // If this assertion fails, it means that some relocation was + // against a portion of an input merge section which we didn't map + // to the output file and we didn't explicitly discard. We should + // always map all portions of input merge sections. + gold_assert(found); + + if (output_offset == -1) + return 0; + else + return this->output_start_address_ + output_offset; +} + +// Track_relocs methods. + +// Initialize the class to track the relocs. This gets the object, +// the reloc section index, and the type of the relocs. This returns +// false if something goes wrong. + +template +bool +Track_relocs::initialize( + Object* object, + unsigned int reloc_shndx, + unsigned int reloc_type) +{ + // If RELOC_SHNDX is -1U, it means there is more than one reloc + // section for the .eh_frame section. We can't handle that case. + if (reloc_shndx == -1U) + return false; + + // If RELOC_SHNDX is 0, there is no reloc section. + if (reloc_shndx == 0) + return true; + + // Get the contents of the reloc section. + this->prelocs_ = object->section_contents(reloc_shndx, &this->len_, false); + + if (reloc_type == elfcpp::SHT_REL) + this->reloc_size_ = elfcpp::Elf_sizes::rel_size; + else if (reloc_type == elfcpp::SHT_RELA) + this->reloc_size_ = elfcpp::Elf_sizes::rela_size; + else + gold_unreachable(); + + if (this->len_ % this->reloc_size_ != 0) + { + object->error(_("reloc section size %zu is not a multiple of " + "reloc size %d\n"), + static_cast(this->len_), + this->reloc_size_); + return false; + } + + return true; +} + +// Return the offset of the next reloc, or -1 if there isn't one. + +template +off_t +Track_relocs::next_offset() const +{ + if (this->pos_ >= this->len_) + return -1; + + // Rel and Rela start out the same, so we can always use Rel to find + // the r_offset value. + elfcpp::Rel rel(this->prelocs_ + this->pos_); + return rel.get_r_offset(); +} + +// Return the index of the symbol referenced by the next reloc, or -1U +// if there aren't any more relocs. + +template +unsigned int +Track_relocs::next_symndx() const +{ + if (this->pos_ >= this->len_) + return -1U; + + // Rel and Rela start out the same, so we can use Rel to find the + // symbol index. + elfcpp::Rel rel(this->prelocs_ + this->pos_); + return elfcpp::elf_r_sym(rel.get_r_info()); +} + +// Advance to the next reloc whose r_offset is greater than or equal +// to OFFSET. Return the number of relocs we skip. + +template +int +Track_relocs::advance(off_t offset) +{ + int ret = 0; + while (this->pos_ < this->len_) + { + // Rel and Rela start out the same, so we can always use Rel to + // find the r_offset value. + elfcpp::Rel rel(this->prelocs_ + this->pos_); + if (static_cast(rel.get_r_offset()) >= offset) + break; + ++ret; + this->pos_ += this->reloc_size_; + } + return ret; +} + +// Instantiate the templates we need. + +#ifdef HAVE_TARGET_32_LITTLE +template +void +Sized_relobj<32, false>::do_read_relocs(Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +void +Sized_relobj<32, true>::do_read_relocs(Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +void +Sized_relobj<64, false>::do_read_relocs(Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +void +Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +void +Sized_relobj<32, false>::do_gc_process_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +void +Sized_relobj<32, true>::do_gc_process_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +void +Sized_relobj<64, false>::do_gc_process_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +void +Sized_relobj<64, true>::do_gc_process_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +void +Sized_relobj<32, false>::do_scan_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +void +Sized_relobj<32, true>::do_scan_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +void +Sized_relobj<64, false>::do_scan_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +void +Sized_relobj<64, true>::do_scan_relocs(const General_options& options, + Symbol_table* symtab, + Layout* layout, + Read_relocs_data* rd); +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +void +Sized_relobj<32, false>::do_relocate(const General_options& options, + const Symbol_table* symtab, + const Layout* layout, + Output_file* of); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +void +Sized_relobj<32, true>::do_relocate(const General_options& options, + const Symbol_table* symtab, + const Layout* layout, + Output_file* of); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +void +Sized_relobj<64, false>::do_relocate(const General_options& options, + const Symbol_table* symtab, + const Layout* layout, + Output_file* of); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +void +Sized_relobj<64, true>::do_relocate(const General_options& options, + const Symbol_table* symtab, + const Layout* layout, + Output_file* of); +#endif + +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) +template +class Merged_symbol_value<32>; +#endif + +#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) +template +class Merged_symbol_value<64>; +#endif + +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) +template +class Symbol_value<32>; +#endif + +#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) +template +class Symbol_value<64>; +#endif + +#ifdef HAVE_TARGET_32_LITTLE +template +class Track_relocs<32, false>; +#endif + +#ifdef HAVE_TARGET_32_BIG +template +class Track_relocs<32, true>; +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +class Track_relocs<64, false>; +#endif + +#ifdef HAVE_TARGET_64_BIG +template +class Track_relocs<64, true>; +#endif + +} // End namespace gold.