diff options
Diffstat (limited to 'gold/dwarf_reader.cc')
| -rw-r--r-- | gold/dwarf_reader.cc | 1440 |
1 files changed, 1391 insertions, 49 deletions
diff --git a/gold/dwarf_reader.cc b/gold/dwarf_reader.cc index 189e6a6..eaf35bf 100644 --- a/gold/dwarf_reader.cc +++ b/gold/dwarf_reader.cc @@ -1,6 +1,6 @@ // dwarf_reader.cc -- parse dwarf2/3 debug information -// Copyright 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. +// Copyright 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc. // Written by Ian Lance Taylor <iant@google.com>. // This file is part of gold. @@ -36,6 +36,1367 @@ namespace gold { +// Class Sized_elf_reloc_mapper + +// Initialize the relocation tracker for section RELOC_SHNDX. + +template<int size, bool big_endian> +bool +Sized_elf_reloc_mapper<size, big_endian>::do_initialize( + unsigned int reloc_shndx, unsigned int reloc_type) +{ + this->reloc_type_ = reloc_type; + return this->track_relocs_.initialize(this->object_, reloc_shndx, + reloc_type); +} + +// Looks in the symtab to see what section a symbol is in. + +template<int size, bool big_endian> +unsigned int +Sized_elf_reloc_mapper<size, big_endian>::symbol_section( + unsigned int symndx, Address* value, bool* is_ordinary) +{ + const int symsize = elfcpp::Elf_sizes<size>::sym_size; + gold_assert((symndx + 1) * symsize <= this->symtab_size_); + elfcpp::Sym<size, big_endian> elfsym(this->symtab_ + symndx * symsize); + *value = elfsym.get_st_value(); + return this->object_->adjust_sym_shndx(symndx, elfsym.get_st_shndx(), + is_ordinary); +} + +// Return the section index and offset within the section of +// the target of the relocation for RELOC_OFFSET. + +template<int size, bool big_endian> +unsigned int +Sized_elf_reloc_mapper<size, big_endian>::do_get_reloc_target( + off_t reloc_offset, off_t* target_offset) +{ + this->track_relocs_.advance(reloc_offset); + if (reloc_offset != this->track_relocs_.next_offset()) + return 0; + unsigned int symndx = this->track_relocs_.next_symndx(); + typename elfcpp::Elf_types<size>::Elf_Addr value; + bool is_ordinary; + unsigned int target_shndx = this->symbol_section(symndx, &value, + &is_ordinary); + if (!is_ordinary) + return 0; + if (this->reloc_type_ == elfcpp::SHT_RELA) + value += this->track_relocs_.next_addend(); + *target_offset = value; + return target_shndx; +} + +static inline Elf_reloc_mapper* +make_elf_reloc_mapper(Object* object, const unsigned char* symtab, + off_t symtab_size) +{ + switch (parameters->size_and_endianness()) + { +#ifdef HAVE_TARGET_32_LITTLE + case Parameters::TARGET_32_LITTLE: + return new Sized_elf_reloc_mapper<32, false>(object, symtab, + symtab_size); +#endif +#ifdef HAVE_TARGET_32_BIG + case Parameters::TARGET_32_BIG: + return new Sized_elf_reloc_mapper<32, true>(object, symtab, + symtab_size); +#endif +#ifdef HAVE_TARGET_64_LITTLE + case Parameters::TARGET_64_LITTLE: + return new Sized_elf_reloc_mapper<64, false>(object, symtab, + symtab_size); +#endif +#ifdef HAVE_TARGET_64_BIG + case Parameters::TARGET_64_BIG: + return new Sized_elf_reloc_mapper<64, true>(object, symtab, + symtab_size); +#endif + default: + gold_unreachable(); + } +} + +// class Dwarf_abbrev_table + +void +Dwarf_abbrev_table::clear_abbrev_codes() +{ + for (unsigned int code = 0; code < this->low_abbrev_code_max_; ++code) + { + if (this->low_abbrev_codes_[code] != NULL) + { + delete this->low_abbrev_codes_[code]; + this->low_abbrev_codes_[code] = NULL; + } + } + for (Abbrev_code_table::iterator it = this->high_abbrev_codes_.begin(); + it != this->high_abbrev_codes_.end(); + ++it) + { + if (it->second != NULL) + delete it->second; + } + this->high_abbrev_codes_.clear(); +} + +// Read the abbrev table from an object file. + +bool +Dwarf_abbrev_table::do_read_abbrevs( + Relobj* object, + unsigned int abbrev_shndx, + off_t abbrev_offset) +{ + this->clear_abbrev_codes(); + + // If we don't have relocations, abbrev_shndx will be 0, and + // we'll have to hunt for the .debug_abbrev section. + if (abbrev_shndx == 0 && this->abbrev_shndx_ > 0) + abbrev_shndx = this->abbrev_shndx_; + else if (abbrev_shndx == 0) + { + for (unsigned int i = 1; i < object->shnum(); ++i) + { + std::string name = object->section_name(i); + if (name == ".debug_abbrev") + { + abbrev_shndx = i; + // Correct the offset. For incremental update links, we have a + // relocated offset that is relative to the output section, but + // here we need an offset relative to the input section. + abbrev_offset -= object->output_section_offset(i); + break; + } + } + if (abbrev_shndx == 0) + return false; + } + + // Get the section contents and decompress if necessary. + if (abbrev_shndx != this->abbrev_shndx_) + { + if (this->owns_buffer_ && this->buffer_ != NULL) + { + delete[] this->buffer_; + this->owns_buffer_ = false; + } + + section_size_type buffer_size; + this->buffer_ = + object->decompressed_section_contents(abbrev_shndx, + &buffer_size, + &this->owns_buffer_); + this->buffer_end_ = this->buffer_ + buffer_size; + this->abbrev_shndx_ = abbrev_shndx; + } + + this->buffer_pos_ = this->buffer_ + abbrev_offset; + return true; +} + +// Lookup the abbrev code entry for CODE. This function is called +// only when the abbrev code is not in the direct lookup table. +// It may be in the hash table, it may not have been read yet, +// or it may not exist in the abbrev table. + +const Dwarf_abbrev_table::Abbrev_code* +Dwarf_abbrev_table::do_get_abbrev(unsigned int code) +{ + // See if the abbrev code is already in the hash table. + Abbrev_code_table::const_iterator it = this->high_abbrev_codes_.find(code); + if (it != this->high_abbrev_codes_.end()) + return it->second; + + // Read and store abbrev code definitions until we find the + // one we're looking for. + for (;;) + { + // Read the abbrev code. A zero here indicates the end of the + // abbrev table. + size_t len; + if (this->buffer_pos_ >= this->buffer_end_) + return NULL; + uint64_t nextcode = read_unsigned_LEB_128(this->buffer_pos_, &len); + if (nextcode == 0) + { + this->buffer_pos_ = this->buffer_end_; + return NULL; + } + this->buffer_pos_ += len; + + // Read the tag. + if (this->buffer_pos_ >= this->buffer_end_) + return NULL; + uint64_t tag = read_unsigned_LEB_128(this->buffer_pos_, &len); + this->buffer_pos_ += len; + + // Read the has_children flag. + if (this->buffer_pos_ >= this->buffer_end_) + return NULL; + bool has_children = *this->buffer_pos_ == elfcpp::DW_CHILDREN_yes; + this->buffer_pos_ += 1; + + // Read the list of (attribute, form) pairs. + Abbrev_code* entry = new Abbrev_code(tag, has_children); + for (;;) + { + // Read the attribute. + if (this->buffer_pos_ >= this->buffer_end_) + return NULL; + uint64_t attr = read_unsigned_LEB_128(this->buffer_pos_, &len); + this->buffer_pos_ += len; + + // Read the form. + if (this->buffer_pos_ >= this->buffer_end_) + return NULL; + uint64_t form = read_unsigned_LEB_128(this->buffer_pos_, &len); + this->buffer_pos_ += len; + + // A (0,0) pair terminates the list. + if (attr == 0 && form == 0) + break; + + if (attr == elfcpp::DW_AT_sibling) + entry->has_sibling_attribute = true; + + entry->add_attribute(attr, form); + } + + this->store_abbrev(nextcode, entry); + if (nextcode == code) + return entry; + } + + return NULL; +} + +// class Dwarf_ranges_table + +// Read the ranges table from an object file. + +bool +Dwarf_ranges_table::read_ranges_table( + Relobj* object, + const unsigned char* symtab, + off_t symtab_size, + unsigned int ranges_shndx) +{ + // If we've already read this abbrev table, return immediately. + if (this->ranges_shndx_ > 0 + && this->ranges_shndx_ == ranges_shndx) + return true; + + // If we don't have relocations, ranges_shndx will be 0, and + // we'll have to hunt for the .debug_ranges section. + if (ranges_shndx == 0 && this->ranges_shndx_ > 0) + ranges_shndx = this->ranges_shndx_; + else if (ranges_shndx == 0) + { + for (unsigned int i = 1; i < object->shnum(); ++i) + { + std::string name = object->section_name(i); + if (name == ".debug_ranges") + { + ranges_shndx = i; + this->output_section_offset_ = object->output_section_offset(i); + break; + } + } + if (ranges_shndx == 0) + return false; + } + + // Get the section contents and decompress if necessary. + if (ranges_shndx != this->ranges_shndx_) + { + if (this->owns_ranges_buffer_ && this->ranges_buffer_ != NULL) + { + delete[] this->ranges_buffer_; + this->owns_ranges_buffer_ = false; + } + + section_size_type buffer_size; + this->ranges_buffer_ = + object->decompressed_section_contents(ranges_shndx, + &buffer_size, + &this->owns_ranges_buffer_); + this->ranges_buffer_end_ = this->ranges_buffer_ + buffer_size; + this->ranges_shndx_ = ranges_shndx; + } + + if (this->ranges_reloc_mapper_ != NULL) + { + delete this->ranges_reloc_mapper_; + this->ranges_reloc_mapper_ = NULL; + } + + // For incremental objects, we have no relocations. + if (object->is_incremental()) + return true; + + // Find the relocation section for ".debug_ranges". + unsigned int reloc_shndx = 0; + unsigned int reloc_type = 0; + for (unsigned int i = 0; i < object->shnum(); ++i) + { + reloc_type = object->section_type(i); + if ((reloc_type == elfcpp::SHT_REL + || reloc_type == elfcpp::SHT_RELA) + && object->section_info(i) == ranges_shndx) + { + reloc_shndx = i; + break; + } + } + + this->ranges_reloc_mapper_ = make_elf_reloc_mapper(object, symtab, + symtab_size); + this->ranges_reloc_mapper_->initialize(reloc_shndx, reloc_type); + + return true; +} + +// Read a range list from section RANGES_SHNDX at offset RANGES_OFFSET. + +Dwarf_range_list* +Dwarf_ranges_table::read_range_list( + Relobj* object, + const unsigned char* symtab, + off_t symtab_size, + unsigned int addr_size, + unsigned int ranges_shndx, + off_t offset) +{ + Dwarf_range_list* ranges; + + if (!this->read_ranges_table(object, symtab, symtab_size, ranges_shndx)) + return NULL; + + // Correct the offset. For incremental update links, we have a + // relocated offset that is relative to the output section, but + // here we need an offset relative to the input section. + offset -= this->output_section_offset_; + + // Read the range list at OFFSET. + ranges = new Dwarf_range_list(); + off_t base = 0; + for (; + this->ranges_buffer_ + offset < this->ranges_buffer_end_; + offset += 2 * addr_size) + { + off_t start; + off_t end; + + // Read the raw contents of the section. + if (addr_size == 4) + { + start = read_from_pointer<32>(this->ranges_buffer_ + offset); + end = read_from_pointer<32>(this->ranges_buffer_ + offset + 4); + } + else + { + start = read_from_pointer<64>(this->ranges_buffer_ + offset); + end = read_from_pointer<64>(this->ranges_buffer_ + offset + 8); + } + + // Check for relocations and adjust the values. + unsigned int shndx1 = 0; + unsigned int shndx2 = 0; + if (this->ranges_reloc_mapper_ != NULL) + { + shndx1 = + this->ranges_reloc_mapper_->get_reloc_target(offset, &start); + shndx2 = + this->ranges_reloc_mapper_->get_reloc_target(offset + addr_size, + &end); + } + + // End of list is marked by a pair of zeroes. + if (shndx1 == 0 && start == 0 && end == 0) + break; + + // A "base address selection entry" is identified by + // 0xffffffff for the first value of the pair. The second + // value is used as a base for subsequent range list entries. + if (shndx1 == 0 && start == -1) + base = end; + else if (shndx1 == shndx2) + { + if (shndx1 == 0 || object->is_section_included(shndx1)) + ranges->add(shndx1, base + start, base + end); + } + else + gold_warning(_("%s: DWARF info may be corrupt; offsets in a " + "range list entry are in different sections"), + object->name().c_str()); + } + + return ranges; +} + +// class Dwarf_pubnames_table + +// Read the pubnames section SHNDX from the object file. + +bool +Dwarf_pubnames_table::read_section(Relobj* object, unsigned int shndx) +{ + section_size_type buffer_size; + + // If we don't have relocations, shndx will be 0, and + // we'll have to hunt for the .debug_pubnames/pubtypes section. + if (shndx == 0) + { + const char* name = (this->is_pubtypes_ + ? ".debug_pubtypes" + : ".debug_pubnames"); + for (unsigned int i = 1; i < object->shnum(); ++i) + { + if (object->section_name(i) == name) + { + shndx = i; + this->output_section_offset_ = object->output_section_offset(i); + break; + } + } + if (shndx == 0) + return false; + } + + this->buffer_ = object->decompressed_section_contents(shndx, + &buffer_size, + &this->owns_buffer_); + if (this->buffer_ == NULL) + return false; + this->buffer_end_ = this->buffer_ + buffer_size; + return true; +} + +// Read the header for the set at OFFSET. + +bool +Dwarf_pubnames_table::read_header(off_t offset) +{ + // Correct the offset. For incremental update links, we have a + // relocated offset that is relative to the output section, but + // here we need an offset relative to the input section. + offset -= this->output_section_offset_; + + if (offset < 0 || offset + 14 >= this->buffer_end_ - this->buffer_) + return false; + + const unsigned char* pinfo = this->buffer_ + offset; + + // Read the unit_length field. + uint32_t unit_length = read_from_pointer<32>(pinfo); + pinfo += 4; + if (unit_length == 0xffffffff) + { + unit_length = read_from_pointer<64>(pinfo); + pinfo += 8; + this->offset_size_ = 8; + } + else + this->offset_size_ = 4; + + // Check the version. + unsigned int version = read_from_pointer<16>(pinfo); + pinfo += 2; + if (version != 2) + return false; + + // Skip the debug_info_offset and debug_info_size fields. + pinfo += 2 * this->offset_size_; + + if (pinfo >= this->buffer_end_) + return false; + + this->pinfo_ = pinfo; + return true; +} + +// Read the next name from the set. + +const char* +Dwarf_pubnames_table::next_name() +{ + const unsigned char* pinfo = this->pinfo_; + + // Read the offset within the CU. If this is zero, we have reached + // the end of the list. + uint32_t offset; + if (this->offset_size_ == 4) + offset = read_from_pointer<32>(&pinfo); + else + offset = read_from_pointer<64>(&pinfo); + if (offset == 0) + return NULL; + + // Return a pointer to the string at the current location, + // and advance the pointer to the next entry. + const char* ret = reinterpret_cast<const char*>(pinfo); + while (pinfo < this->buffer_end_ && *pinfo != '\0') + ++pinfo; + if (pinfo < this->buffer_end_) + ++pinfo; + + this->pinfo_ = pinfo; + return ret; +} + +// class Dwarf_die + +Dwarf_die::Dwarf_die( + Dwarf_info_reader* dwinfo, + off_t die_offset, + Dwarf_die* parent) + : dwinfo_(dwinfo), parent_(parent), die_offset_(die_offset), + child_offset_(0), sibling_offset_(0), abbrev_code_(NULL), attributes_(), + attributes_read_(false), name_(NULL), name_off_(-1), linkage_name_(NULL), + linkage_name_off_(-1), string_shndx_(0), specification_(0), + abstract_origin_(0) +{ + size_t len; + const unsigned char* pdie = dwinfo->buffer_at_offset(die_offset); + if (pdie == NULL) + return; + unsigned int code = read_unsigned_LEB_128(pdie, &len); + if (code == 0) + { + if (parent != NULL) + parent->set_sibling_offset(die_offset + len); + return; + } + this->attr_offset_ = len; + + // Lookup the abbrev code in the abbrev table. + this->abbrev_code_ = dwinfo->get_abbrev(code); +} + +// Read all the attributes of the DIE. + +bool +Dwarf_die::read_attributes() +{ + if (this->attributes_read_) + return true; + + gold_assert(this->abbrev_code_ != NULL); + + const unsigned char* pdie = + this->dwinfo_->buffer_at_offset(this->die_offset_); + if (pdie == NULL) + return false; + const unsigned char* pattr = pdie + this->attr_offset_; + + unsigned int nattr = this->abbrev_code_->attributes.size(); + this->attributes_.reserve(nattr); + for (unsigned int i = 0; i < nattr; ++i) + { + size_t len; + unsigned int attr = this->abbrev_code_->attributes[i].attr; + unsigned int form = this->abbrev_code_->attributes[i].form; + if (form == elfcpp::DW_FORM_indirect) + { + form = read_unsigned_LEB_128(pattr, &len); + pattr += len; + } + off_t attr_off = this->die_offset_ + (pattr - pdie); + bool ref_form = false; + Attribute_value attr_value; + attr_value.attr = attr; + attr_value.form = form; + attr_value.aux.shndx = 0; + switch(form) + { + case elfcpp::DW_FORM_null: + attr_value.val.intval = 0; + break; + case elfcpp::DW_FORM_flag_present: + attr_value.val.intval = 1; + break; + case elfcpp::DW_FORM_strp: + { + off_t str_off; + if (this->dwinfo_->offset_size() == 4) + str_off = read_from_pointer<32>(&pattr); + else + str_off = read_from_pointer<64>(&pattr); + unsigned int shndx = + this->dwinfo_->lookup_reloc(attr_off, &str_off); + attr_value.aux.shndx = shndx; + attr_value.val.refval = str_off; + break; + } + case elfcpp::DW_FORM_sec_offset: + { + off_t sec_off; + if (this->dwinfo_->offset_size() == 4) + sec_off = read_from_pointer<32>(&pattr); + else + sec_off = read_from_pointer<64>(&pattr); + unsigned int shndx = + this->dwinfo_->lookup_reloc(attr_off, &sec_off); + attr_value.aux.shndx = shndx; + attr_value.val.refval = sec_off; + ref_form = true; + break; + } + case elfcpp::DW_FORM_addr: + case elfcpp::DW_FORM_ref_addr: + { + off_t sec_off; + if (this->dwinfo_->address_size() == 4) + sec_off = read_from_pointer<32>(&pattr); + else + sec_off = read_from_pointer<64>(&pattr); + unsigned int shndx = + this->dwinfo_->lookup_reloc(attr_off, &sec_off); + attr_value.aux.shndx = shndx; + attr_value.val.refval = sec_off; + ref_form = true; + break; + } + case elfcpp::DW_FORM_block1: + attr_value.aux.blocklen = *pattr++; + attr_value.val.blockval = pattr; + pattr += attr_value.aux.blocklen; + break; + case elfcpp::DW_FORM_block2: + attr_value.aux.blocklen = read_from_pointer<16>(&pattr); + attr_value.val.blockval = pattr; + pattr += attr_value.aux.blocklen; + break; + case elfcpp::DW_FORM_block4: + attr_value.aux.blocklen = read_from_pointer<32>(&pattr); + attr_value.val.blockval = pattr; + pattr += attr_value.aux.blocklen; + break; + case elfcpp::DW_FORM_block: + case elfcpp::DW_FORM_exprloc: + attr_value.aux.blocklen = read_unsigned_LEB_128(pattr, &len); + attr_value.val.blockval = pattr + len; + pattr += len + attr_value.aux.blocklen; + break; + case elfcpp::DW_FORM_data1: + case elfcpp::DW_FORM_flag: + attr_value.val.intval = *pattr++; + break; + case elfcpp::DW_FORM_ref1: + attr_value.val.refval = *pattr++; + ref_form = true; + break; + case elfcpp::DW_FORM_data2: + attr_value.val.intval = read_from_pointer<16>(&pattr); + break; + case elfcpp::DW_FORM_ref2: + attr_value.val.refval = read_from_pointer<16>(&pattr); + ref_form = true; + break; + case elfcpp::DW_FORM_data4: + { + off_t sec_off; + sec_off = read_from_pointer<32>(&pattr); + unsigned int shndx = + this->dwinfo_->lookup_reloc(attr_off, &sec_off); + attr_value.aux.shndx = shndx; + attr_value.val.intval = sec_off; + break; + } + case elfcpp::DW_FORM_ref4: + { + off_t sec_off; + sec_off = read_from_pointer<32>(&pattr); + unsigned int shndx = + this->dwinfo_->lookup_reloc(attr_off, &sec_off); + attr_value.aux.shndx = shndx; + attr_value.val.refval = sec_off; + ref_form = true; + break; + } + case elfcpp::DW_FORM_data8: + { + off_t sec_off; + sec_off = read_from_pointer<64>(&pattr); + unsigned int shndx = + this->dwinfo_->lookup_reloc(attr_off, &sec_off); + attr_value.aux.shndx = shndx; + attr_value.val.intval = sec_off; + break; + } + case elfcpp::DW_FORM_ref_sig8: + attr_value.val.uintval = read_from_pointer<64>(&pattr); + break; + case elfcpp::DW_FORM_ref8: + { + off_t sec_off; + sec_off = read_from_pointer<64>(&pattr); + unsigned int shndx = + this->dwinfo_->lookup_reloc(attr_off, &sec_off); + attr_value.aux.shndx = shndx; + attr_value.val.refval = sec_off; + ref_form = true; + break; + } + case elfcpp::DW_FORM_ref_udata: + attr_value.val.refval = read_unsigned_LEB_128(pattr, &len); + ref_form = true; + pattr += len; + break; + case elfcpp::DW_FORM_udata: + attr_value.val.uintval = read_unsigned_LEB_128(pattr, &len); + pattr += len; + break; + case elfcpp::DW_FORM_sdata: + attr_value.val.intval = read_signed_LEB_128(pattr, &len); + pattr += len; + break; + case elfcpp::DW_FORM_string: + attr_value.val.stringval = reinterpret_cast<const char*>(pattr); + len = strlen(attr_value.val.stringval); + pattr += len + 1; + break; + default: + return false; + } + + // Cache the most frequently-requested attributes. + switch (attr) + { + case elfcpp::DW_AT_name: + if (form == elfcpp::DW_FORM_string) + this->name_ = attr_value.val.stringval; + else if (form == elfcpp::DW_FORM_strp) + { + // All indirect strings should refer to the same + // string section, so we just save the last one seen. + this->string_shndx_ = attr_value.aux.shndx; + this->name_off_ = attr_value.val.refval; + } + break; + case elfcpp::DW_AT_linkage_name: + case elfcpp::DW_AT_MIPS_linkage_name: + if (form == elfcpp::DW_FORM_string) + this->linkage_name_ = attr_value.val.stringval; + else if (form == elfcpp::DW_FORM_strp) + { + // All indirect strings should refer to the same + // string section, so we just save the last one seen. + this->string_shndx_ = attr_value.aux.shndx; + this->linkage_name_off_ = attr_value.val.refval; + } + break; + case elfcpp::DW_AT_specification: + if (ref_form) + this->specification_ = attr_value.val.refval; + break; + case elfcpp::DW_AT_abstract_origin: + if (ref_form) + this->abstract_origin_ = attr_value.val.refval; + break; + case elfcpp::DW_AT_sibling: + if (ref_form && attr_value.aux.shndx == 0) + this->sibling_offset_ = attr_value.val.refval; + default: + break; + } + + this->attributes_.push_back(attr_value); + } + + // Now that we know where the next DIE begins, record the offset + // to avoid later recalculation. + if (this->has_children()) + this->child_offset_ = this->die_offset_ + (pattr - pdie); + else + this->sibling_offset_ = this->die_offset_ + (pattr - pdie); + + this->attributes_read_ = true; + return true; +} + +// Skip all the attributes of the DIE and return the offset of the next DIE. + +off_t +Dwarf_die::skip_attributes() +{ + typedef Dwarf_abbrev_table::Attribute Attribute; + + gold_assert(this->abbrev_code_ != NULL); + + const unsigned char* pdie = + this->dwinfo_->buffer_at_offset(this->die_offset_); + if (pdie == NULL) + return 0; + const unsigned char* pattr = pdie + this->attr_offset_; + + for (unsigned int i = 0; i < this->abbrev_code_->attributes.size(); ++i) + { + size_t len; + unsigned int form = this->abbrev_code_->attributes[i].form; + if (form == elfcpp::DW_FORM_indirect) + { + form = read_unsigned_LEB_128(pattr, &len); + pattr += len; + } + switch(form) + { + case elfcpp::DW_FORM_null: + case elfcpp::DW_FORM_flag_present: + break; + case elfcpp::DW_FORM_strp: + case elfcpp::DW_FORM_sec_offset: + pattr += this->dwinfo_->offset_size(); + break; + case elfcpp::DW_FORM_addr: + case elfcpp::DW_FORM_ref_addr: + pattr += this->dwinfo_->address_size(); + break; + case elfcpp::DW_FORM_block1: + pattr += 1 + *pattr; + break; + case elfcpp::DW_FORM_block2: + { + uint16_t block_size; + block_size = read_from_pointer<16>(&pattr); + pattr += block_size; + break; + } + case elfcpp::DW_FORM_block4: + { + uint32_t block_size; + block_size = read_from_pointer<32>(&pattr); + pattr += block_size; + break; + } + case elfcpp::DW_FORM_block: + case elfcpp::DW_FORM_exprloc: + { + uint64_t block_size; + block_size = read_unsigned_LEB_128(pattr, &len); + pattr += len + block_size; + break; + } + case elfcpp::DW_FORM_data1: + case elfcpp::DW_FORM_ref1: + case elfcpp::DW_FORM_flag: + pattr += 1; + break; + case elfcpp::DW_FORM_data2: + case elfcpp::DW_FORM_ref2: + pattr += 2; + break; + case elfcpp::DW_FORM_data4: + case elfcpp::DW_FORM_ref4: + pattr += 4; + break; + case elfcpp::DW_FORM_data8: + case elfcpp::DW_FORM_ref8: + case elfcpp::DW_FORM_ref_sig8: + pattr += 8; + break; + case elfcpp::DW_FORM_ref_udata: + case elfcpp::DW_FORM_udata: + read_unsigned_LEB_128(pattr, &len); + pattr += len; + break; + case elfcpp::DW_FORM_sdata: + read_signed_LEB_128(pattr, &len); + pattr += len; + break; + case elfcpp::DW_FORM_string: + len = strlen(reinterpret_cast<const char*>(pattr)); + pattr += len + 1; + break; + default: + return 0; + } + } + + return this->die_offset_ + (pattr - pdie); +} + +// Get the name of the DIE and cache it. + +void +Dwarf_die::set_name() +{ + if (this->name_ != NULL || !this->read_attributes()) + return; + if (this->name_off_ != -1) + this->name_ = this->dwinfo_->get_string(this->name_off_, + this->string_shndx_); +} + +// Get the linkage name of the DIE and cache it. + +void +Dwarf_die::set_linkage_name() +{ + if (this->linkage_name_ != NULL || !this->read_attributes()) + return; + if (this->linkage_name_off_ != -1) + this->linkage_name_ = this->dwinfo_->get_string(this->linkage_name_off_, + this->string_shndx_); +} + +// Return the value of attribute ATTR. + +const Dwarf_die::Attribute_value* +Dwarf_die::attribute(unsigned int attr) +{ + if (!this->read_attributes()) + return NULL; + for (unsigned int i = 0; i < this->attributes_.size(); ++i) + { + if (this->attributes_[i].attr == attr) + return &this->attributes_[i]; + } + return NULL; +} + +const char* +Dwarf_die::string_attribute(unsigned int attr) +{ + const Attribute_value* attr_val = this->attribute(attr); + if (attr_val == NULL) + return NULL; + switch (attr_val->form) + { + case elfcpp::DW_FORM_string: + return attr_val->val.stringval; + case elfcpp::DW_FORM_strp: + return this->dwinfo_->get_string(attr_val->val.refval, + attr_val->aux.shndx); + default: + return NULL; + } +} + +int64_t +Dwarf_die::int_attribute(unsigned int attr) +{ + const Attribute_value* attr_val = this->attribute(attr); + if (attr_val == NULL) + return 0; + switch (attr_val->form) + { + case elfcpp::DW_FORM_null: + case elfcpp::DW_FORM_flag_present: + case elfcpp::DW_FORM_data1: + case elfcpp::DW_FORM_flag: + case elfcpp::DW_FORM_data2: + case elfcpp::DW_FORM_data4: + case elfcpp::DW_FORM_data8: + case elfcpp::DW_FORM_sdata: + return attr_val->val.intval; + default: + return 0; + } +} + +uint64_t +Dwarf_die::uint_attribute(unsigned int attr) +{ + const Attribute_value* attr_val = this->attribute(attr); + if (attr_val == NULL) + return 0; + switch (attr_val->form) + { + case elfcpp::DW_FORM_null: + case elfcpp::DW_FORM_flag_present: + case elfcpp::DW_FORM_data1: + case elfcpp::DW_FORM_flag: + case elfcpp::DW_FORM_data4: + case elfcpp::DW_FORM_data8: + case elfcpp::DW_FORM_ref_sig8: + case elfcpp::DW_FORM_udata: + return attr_val->val.uintval; + default: + return 0; + } +} + +off_t +Dwarf_die::ref_attribute(unsigned int attr, unsigned int* shndx) +{ + const Attribute_value* attr_val = this->attribute(attr); + if (attr_val == NULL) + return -1; + switch (attr_val->form) + { + case elfcpp::DW_FORM_sec_offset: + case elfcpp::DW_FORM_addr: + case elfcpp::DW_FORM_ref_addr: + case elfcpp::DW_FORM_ref1: + case elfcpp::DW_FORM_ref2: + case elfcpp::DW_FORM_ref4: + case elfcpp::DW_FORM_ref8: + case elfcpp::DW_FORM_ref_udata: + *shndx = attr_val->aux.shndx; + return attr_val->val.refval; + case elfcpp::DW_FORM_ref_sig8: + *shndx = attr_val->aux.shndx; + return attr_val->val.uintval; + case elfcpp::DW_FORM_data4: + case elfcpp::DW_FORM_data8: + *shndx = attr_val->aux.shndx; + return attr_val->val.intval; + default: + return -1; + } +} + +// Return the offset of this DIE's first child. + +off_t +Dwarf_die::child_offset() +{ + gold_assert(this->abbrev_code_ != NULL); + if (!this->has_children()) + return 0; + if (this->child_offset_ == 0) + this->child_offset_ = this->skip_attributes(); + return this->child_offset_; +} + +// Return the offset of this DIE's next sibling. + +off_t +Dwarf_die::sibling_offset() +{ + gold_assert(this->abbrev_code_ != NULL); + + if (this->sibling_offset_ != 0) + return this->sibling_offset_; + + if (!this->has_children()) + { + this->sibling_offset_ = this->skip_attributes(); + return this->sibling_offset_; + } + + if (this->has_sibling_attribute()) + { + if (!this->read_attributes()) + return 0; + if (this->sibling_offset_ != 0) + return this->sibling_offset_; + } + + // Skip over the children. + off_t child_offset = this->child_offset(); + while (child_offset > 0) + { + Dwarf_die die(this->dwinfo_, child_offset, this); + // The Dwarf_die ctor will set this DIE's sibling offset + // when it reads a zero abbrev code. + if (die.tag() == 0) + break; + child_offset = die.sibling_offset(); + } + + // This should be set by now. If not, there was a problem reading + // the DWARF info, and we return 0. + return this->sibling_offset_; +} + +// class Dwarf_info_reader + +// Check that the pointer P is within the current compilation unit. + +inline bool +Dwarf_info_reader::check_buffer(const unsigned char* p) const +{ + if (p > this->buffer_ + this->cu_offset_ + this->cu_length_) + { + gold_warning(_("%s: corrupt debug info in %s"), + this->object_->name().c_str(), + this->object_->section_name(this->shndx_).c_str()); + return false; + } + return true; +} + +// Begin parsing the debug info. This calls visit_compilation_unit() +// or visit_type_unit() for each compilation or type unit found in the +// section, and visit_die() for each top-level DIE. + +void +Dwarf_info_reader::parse() +{ + switch (parameters->size_and_endianness()) + { +#ifdef HAVE_TARGET_32_LITTLE + case Parameters::TARGET_32_LITTLE: + this->do_parse<false>(); + break; +#endif +#ifdef HAVE_TARGET_32_BIG + case Parameters::TARGET_32_BIG: + this->do_parse<true>(); + break; +#endif +#ifdef HAVE_TARGET_64_LITTLE + case Parameters::TARGET_64_LITTLE: + this->do_parse<false>(); + break; +#endif +#ifdef HAVE_TARGET_64_BIG + case Parameters::TARGET_64_BIG: + this->do_parse<true>(); + break; +#endif + default: + gold_unreachable(); + } +} + +template<bool big_endian> +void +Dwarf_info_reader::do_parse() +{ + // Get the section contents and decompress if necessary. + section_size_type buffer_size; + bool buffer_is_new; + this->buffer_ = this->object_->decompressed_section_contents(this->shndx_, + &buffer_size, + &buffer_is_new); + if (this->buffer_ == NULL || buffer_size == 0) + return; + this->buffer_end_ = this->buffer_ + buffer_size; + + // The offset of this input section in the output section. + off_t section_offset = this->object_->output_section_offset(this->shndx_); + + // Start tracking relocations for this section. + this->reloc_mapper_ = make_elf_reloc_mapper(this->object_, this->symtab_, + this->symtab_size_); + this->reloc_mapper_->initialize(this->reloc_shndx_, this->reloc_type_); + + // Loop over compilation units (or type units). + unsigned int abbrev_shndx = 0; + off_t abbrev_offset = 0; + const unsigned char* pinfo = this->buffer_; + while (pinfo < this->buffer_end_) + { + // Read the compilation (or type) unit header. + const unsigned char* cu_start = pinfo; + this->cu_offset_ = cu_start - this->buffer_; + this->cu_length_ = this->buffer_end_ - cu_start; + + // Read unit_length (4 or 12 bytes). + if (!this->check_buffer(pinfo + 4)) + break; + uint32_t unit_length = + elfcpp::Swap_unaligned<32, big_endian>::readval(pinfo); + pinfo += 4; + if (unit_length == 0xffffffff) + { + if (!this->check_buffer(pinfo + 8)) + break; + unit_length = elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo); + pinfo += 8; + this->offset_size_ = 8; + } + else + this->offset_size_ = 4; + if (!this->check_buffer(pinfo + unit_length)) + break; + const unsigned char* cu_end = pinfo + unit_length; + this->cu_length_ = cu_end - cu_start; + if (!this->check_buffer(pinfo + 2 + this->offset_size_ + 1)) + break; + + // Read version (2 bytes). + this->cu_version_ = + elfcpp::Swap_unaligned<16, big_endian>::readval(pinfo); + pinfo += 2; + + // Read debug_abbrev_offset (4 or 8 bytes). + if (this->offset_size_ == 4) + abbrev_offset = elfcpp::Swap_unaligned<32, big_endian>::readval(pinfo); + else + abbrev_offset = elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo); + if (this->reloc_shndx_ > 0) + { + off_t reloc_offset = pinfo - this->buffer_; + off_t value; + abbrev_shndx = + this->reloc_mapper_->get_reloc_target(reloc_offset, &value); + if (abbrev_shndx == 0) + return; + if (this->reloc_type_ == elfcpp::SHT_REL) + abbrev_offset += value; + else + abbrev_offset = value; + } + pinfo += this->offset_size_; + + // Read address_size (1 byte). + this->address_size_ = *pinfo++; + + // For type units, read the two extra fields. + uint64_t signature = 0; + off_t type_offset = 0; + if (this->is_type_unit_) + { + if (!this->check_buffer(pinfo + 8 + this->offset_size_)) + break; + + // Read type_signature (8 bytes). + signature = elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo); + pinfo += 8; + + // Read type_offset (4 or 8 bytes). + if (this->offset_size_ == 4) + type_offset = + elfcpp::Swap_unaligned<32, big_endian>::readval(pinfo); + else + type_offset = + elfcpp::Swap_unaligned<64, big_endian>::readval(pinfo); + pinfo += this->offset_size_; + } + + // Read the .debug_abbrev table. + this->abbrev_table_.read_abbrevs(this->object_, abbrev_shndx, + abbrev_offset); + + // Visit the root DIE. + Dwarf_die root_die(this, + pinfo - (this->buffer_ + this->cu_offset_), + NULL); + if (root_die.tag() != 0) + { + // Visit the CU or TU. + if (this->is_type_unit_) + this->visit_type_unit(section_offset + this->cu_offset_, + type_offset, signature, &root_die); + else + this->visit_compilation_unit(section_offset + this->cu_offset_, + cu_end - cu_start, &root_die); + } + + // Advance to the next CU. + pinfo = cu_end; + } + + if (buffer_is_new) + { + delete[] this->buffer_; + this->buffer_ = NULL; + } +} + +// Read the DWARF string table. + +bool +Dwarf_info_reader::do_read_string_table(unsigned int string_shndx) +{ + Relobj* object = this->object_; + + // If we don't have relocations, string_shndx will be 0, and + // we'll have to hunt for the .debug_str section. + if (string_shndx == 0) + { + for (unsigned int i = 1; i < this->object_->shnum(); ++i) + { + std::string name = object->section_name(i); + if (name == ".debug_str") + { + string_shndx = i; + this->string_output_section_offset_ = + object->output_section_offset(i); + break; + } + } + if (string_shndx == 0) + return false; + } + + if (this->owns_string_buffer_ && this->string_buffer_ != NULL) + { + delete[] this->string_buffer_; + this->owns_string_buffer_ = false; + } + + // Get the secton contents and decompress if necessary. + section_size_type buffer_size; + const unsigned char* buffer = + object->decompressed_section_contents(string_shndx, + &buffer_size, + &this->owns_string_buffer_); + this->string_buffer_ = reinterpret_cast<const char*>(buffer); + this->string_buffer_end_ = this->string_buffer_ + buffer_size; + this->string_shndx_ = string_shndx; + return true; +} + +// Look for a relocation at offset ATTR_OFF in the dwarf info, +// and return the section index and offset of the target. + +unsigned int +Dwarf_info_reader::lookup_reloc(off_t attr_off, off_t* target_off) +{ + off_t value; + attr_off += this->cu_offset_; + unsigned int shndx = this->reloc_mapper_->get_reloc_target(attr_off, &value); + if (shndx == 0) + return 0; + if (this->reloc_type_ == elfcpp::SHT_REL) + *target_off += value; + else + *target_off = value; + return shndx; +} + +// Return a string from the DWARF string table. + +const char* +Dwarf_info_reader::get_string(off_t str_off, unsigned int string_shndx) +{ + if (!this->read_string_table(string_shndx)) + return NULL; + + // Correct the offset. For incremental update links, we have a + // relocated offset that is relative to the output section, but + // here we need an offset relative to the input section. + str_off -= this->string_output_section_offset_; + + const char* p = this->string_buffer_ + str_off; + + if (p < this->string_buffer_ || p >= this->string_buffer_end_) + return NULL; + + return p; +} + +// The following are default, do-nothing, implementations of the +// hook methods normally provided by a derived class. We provide +// default implementations rather than no implementation so that +// a derived class needs to implement only the hooks that it needs +// to use. + +// Process a compilation unit and parse its child DIE. + +void +Dwarf_info_reader::visit_compilation_unit(off_t, off_t, Dwarf_die*) +{ +} + +// Process a type unit and parse its child DIE. + +void +Dwarf_info_reader::visit_type_unit(off_t, off_t, uint64_t, Dwarf_die*) +{ +} + +// class Sized_dwarf_line_info + struct LineStateMachine { int file_num; @@ -66,7 +1427,8 @@ Sized_dwarf_line_info<size, big_endian>::Sized_dwarf_line_info( Object* object, unsigned int read_shndx) : data_valid_(false), buffer_(NULL), buffer_start_(NULL), - symtab_buffer_(NULL), directories_(), files_(), current_header_index_(-1) + reloc_mapper_(NULL), symtab_buffer_(NULL), directories_(), files_(), + current_header_index_(-1) { unsigned int debug_shndx; @@ -92,42 +1454,46 @@ Sized_dwarf_line_info<size, big_endian>::Sized_dwarf_line_info( // Find the relocation section for ".debug_line". // We expect these for relobjs (.o's) but not dynobjs (.so's). - bool got_relocs = false; - for (unsigned int reloc_shndx = 0; - reloc_shndx < object->shnum(); - ++reloc_shndx) + unsigned int reloc_shndx = 0; + for (unsigned int i = 0; i < object->shnum(); ++i) { - unsigned int reloc_sh_type = object->section_type(reloc_shndx); + unsigned int reloc_sh_type = object->section_type(i); if ((reloc_sh_type == elfcpp::SHT_REL || reloc_sh_type == elfcpp::SHT_RELA) - && object->section_info(reloc_shndx) == debug_shndx) + && object->section_info(i) == debug_shndx) { - got_relocs = this->track_relocs_.initialize(object, reloc_shndx, - reloc_sh_type); + reloc_shndx = i; this->track_relocs_type_ = reloc_sh_type; break; } } // Finally, we need the symtab section to interpret the relocs. - if (got_relocs) + if (reloc_shndx != 0) { unsigned int symtab_shndx; for (symtab_shndx = 0; symtab_shndx < object->shnum(); ++symtab_shndx) if (object->section_type(symtab_shndx) == elfcpp::SHT_SYMTAB) { - this->symtab_buffer_ = object->section_contents( - symtab_shndx, &this->symtab_buffer_size_, false); + this->symtab_buffer_ = object->section_contents( + symtab_shndx, &this->symtab_buffer_size_, false); break; } if (this->symtab_buffer_ == NULL) return; } + this->reloc_mapper_ = + new Sized_elf_reloc_mapper<size, big_endian>(object, + this->symtab_buffer_, + this->symtab_buffer_size_); + if (!this->reloc_mapper_->initialize(reloc_shndx, this->track_relocs_type_)) + return; + // Now that we have successfully read all the data, parse the debug // info. this->data_valid_ = true; - this->read_line_mappings(object, read_shndx); + this->read_line_mappings(read_shndx); } // Read the DWARF header. @@ -504,51 +1870,28 @@ Sized_dwarf_line_info<size, big_endian>::read_lines(unsigned const char* lineptr return lengthstart + header_.total_length; } -// Looks in the symtab to see what section a symbol is in. - -template<int size, bool big_endian> -unsigned int -Sized_dwarf_line_info<size, big_endian>::symbol_section( - Object* object, - unsigned int sym, - typename elfcpp::Elf_types<size>::Elf_Addr* value, - bool* is_ordinary) -{ - const int symsize = elfcpp::Elf_sizes<size>::sym_size; - gold_assert(sym * symsize < this->symtab_buffer_size_); - elfcpp::Sym<size, big_endian> elfsym(this->symtab_buffer_ + sym * symsize); - *value = elfsym.get_st_value(); - return object->adjust_sym_shndx(sym, elfsym.get_st_shndx(), is_ordinary); -} - // Read the relocations into a Reloc_map. template<int size, bool big_endian> void -Sized_dwarf_line_info<size, big_endian>::read_relocs(Object* object) +Sized_dwarf_line_info<size, big_endian>::read_relocs() { if (this->symtab_buffer_ == NULL) return; - typename elfcpp::Elf_types<size>::Elf_Addr value; + off_t value; off_t reloc_offset; - while ((reloc_offset = this->track_relocs_.next_offset()) != -1) + while ((reloc_offset = this->reloc_mapper_->next_offset()) != -1) { - const unsigned int sym = this->track_relocs_.next_symndx(); - - bool is_ordinary; - const unsigned int shndx = this->symbol_section(object, sym, &value, - &is_ordinary); + const unsigned int shndx = + this->reloc_mapper_->get_reloc_target(reloc_offset, &value); // There is no reason to record non-ordinary section indexes, or // SHN_UNDEF, because they will never match the real section. - if (is_ordinary && shndx != elfcpp::SHN_UNDEF) - { - value += this->track_relocs_.next_addend(); - this->reloc_map_[reloc_offset] = std::make_pair(shndx, value); - } + if (shndx != 0) + this->reloc_map_[reloc_offset] = std::make_pair(shndx, value); - this->track_relocs_.advance(reloc_offset + 1); + this->reloc_mapper_->advance(reloc_offset + 1); } } @@ -556,12 +1899,11 @@ Sized_dwarf_line_info<size, big_endian>::read_relocs(Object* object) template<int size, bool big_endian> void -Sized_dwarf_line_info<size, big_endian>::read_line_mappings(Object* object, - unsigned int shndx) +Sized_dwarf_line_info<size, big_endian>::read_line_mappings(unsigned int shndx) { gold_assert(this->data_valid_ == true); - this->read_relocs(object); + this->read_relocs(); while (this->buffer_ < this->buffer_end_) { const unsigned char* lineptr = this->buffer_; @@ -765,7 +2107,7 @@ Sized_dwarf_line_info<size, big_endian>::format_file_lineno( gold_assert(loc.header_num < static_cast<int>(this->files_.size())); gold_assert(loc.file_num - < static_cast<int>(this->files_[loc.header_num].size())); + < static_cast<unsigned int>(this->files_[loc.header_num].size())); const std::pair<int, std::string>& filename_pair = this->files_[loc.header_num][loc.file_num]; const std::string& filename = filename_pair.second; |