diff options
Diffstat (limited to 'gold/ehframe.cc')
| -rw-r--r-- | gold/ehframe.cc | 1047 |
1 files changed, 1033 insertions, 14 deletions
diff --git a/gold/ehframe.cc b/gold/ehframe.cc index 607654b..1c7b714 100644 --- a/gold/ehframe.cc +++ b/gold/ehframe.cc @@ -22,8 +22,13 @@ #include "gold.h" +#include <cstring> +#include <algorithm> + #include "elfcpp.h" #include "dwarf.h" +#include "symtab.h" +#include "reloc.h" #include "ehframe.h" namespace gold @@ -31,7 +36,8 @@ namespace gold // This file handles generation of the exception frame header that // gcc's runtime support libraries use to find unwind information at -// runtime. +// runtime. This file also handles discarding duplicate exception +// frame information. // The exception frame header starts with four bytes: @@ -68,16 +74,17 @@ namespace gold // the start of the exception frame header information. The entries // are in sorted order by starting PC. -// FIXME: We currently always generate an empty exception frame -// header. - const int eh_frame_hdr_size = 4; // Construct the exception frame header. -Eh_frame_hdr::Eh_frame_hdr(Output_section* eh_frame_section) +Eh_frame_hdr::Eh_frame_hdr(Output_section* eh_frame_section, + const Eh_frame* eh_frame_data) : Output_section_data(4), - eh_frame_section_(eh_frame_section) + eh_frame_section_(eh_frame_section), + eh_frame_data_(eh_frame_data), + fde_offsets_(), + any_unrecognized_eh_frame_sections_(false) { } @@ -86,7 +93,15 @@ Eh_frame_hdr::Eh_frame_hdr(Output_section* eh_frame_section) void Eh_frame_hdr::do_set_address(uint64_t, off_t) { - this->set_data_size(eh_frame_hdr_size + 4); + unsigned int data_size = eh_frame_hdr_size + 4; + if (!this->any_unrecognized_eh_frame_sections_) + { + unsigned int fde_count = this->eh_frame_data_->fde_count(); + if (fde_count != 0) + data_size += 4 + 8 * fde_count; + this->fde_offsets_.reserve(fde_count); + } + this->set_data_size(data_size); } // Write the data to the flie. @@ -94,6 +109,54 @@ Eh_frame_hdr::do_set_address(uint64_t, off_t) void Eh_frame_hdr::do_write(Output_file* of) { + if (parameters->get_size() == 32) + { + if (!parameters->is_big_endian()) + { +#ifdef HAVE_TARGET_32_LITTLE + this->do_sized_write<32, false>(of); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_32_BIG + this->do_sized_write<32, true>(of); +#else + gold_unreachable(); +#endif + } + } + else if (parameters->get_size() == 64) + { + if (!parameters->is_big_endian()) + { +#ifdef HAVE_TARGET_64_LITTLE + this->do_sized_write<64, false>(of); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_64_BIG + this->do_sized_write<64, true>(of); +#else + gold_unreachable(); +#endif + } + } + else + gold_unreachable(); +} + +// Write the data to the file with the right endianness. + +template<int size, bool big_endian> +void +Eh_frame_hdr::do_sized_write(Output_file* of) +{ const off_t off = this->offset(); const off_t oview_size = this->data_size(); unsigned char* const oview = of->get_output_view(off, oview_size); @@ -108,18 +171,974 @@ Eh_frame_hdr::do_write(Output_file* of) uint64_t eh_frame_hdr_address = this->address(); uint64_t eh_frame_offset = (eh_frame_address - (eh_frame_hdr_address + 4)); - if (parameters->is_big_endian()) - elfcpp::Swap<32, true>::writeval(oview + 4, eh_frame_offset); + elfcpp::Swap<32, big_endian>::writeval(oview + 4, eh_frame_offset); + + if (this->any_unrecognized_eh_frame_sections_ + || this->fde_offsets_.empty()) + { + // There are no FDEs, or we didn't recognize the format of the + // some of the .eh_frame sections, so we can't write out the + // sorted table. + oview[2] = elfcpp::DW_EH_PE_omit; + oview[3] = elfcpp::DW_EH_PE_omit; + + gold_assert(oview_size == 8); + } else - elfcpp::Swap<32, false>::writeval(oview + 4, eh_frame_offset); + { + oview[2] = elfcpp::DW_EH_PE_udata4; + oview[3] = elfcpp::DW_EH_PE_datarel | elfcpp::DW_EH_PE_sdata4; + + elfcpp::Swap<32, big_endian>::writeval(oview + 8, + this->fde_offsets_.size()); + + // We have the offsets of the FDEs in the .eh_frame section. We + // couldn't easily get the PC values before, as they depend on + // relocations which are, of course, target specific. This code + // is run after all those relocations have been applied to the + // output file. Here we read the output file again to find the + // PC values. Then we sort the list and write it out. - // We don't currently write out the sorted table. - oview[2] = elfcpp::DW_EH_PE_omit; - oview[3] = elfcpp::DW_EH_PE_omit; + Fde_addresses<size> fde_addresses(this->fde_offsets_.size()); + this->get_fde_addresses<size, big_endian>(of, &this->fde_offsets_, + &fde_addresses); - gold_assert(oview_size == 8); + std::sort(fde_addresses.begin(), fde_addresses.end(), + Fde_address_compare<size>()); + + typename elfcpp::Elf_types<size>::Elf_Addr output_address; + output_address = this->address(); + + unsigned char* pfde = oview + 12; + for (typename Fde_addresses<size>::iterator p = fde_addresses.begin(); + p != fde_addresses.end(); + ++p) + { + elfcpp::Swap<32, big_endian>::writeval(pfde, + p->first - output_address); + elfcpp::Swap<32, big_endian>::writeval(pfde + 4, + p->second - output_address); + pfde += 8; + } + + gold_assert(pfde - oview == oview_size); + } of->write_output_view(off, oview_size, oview); } +// Given the offset FDE_OFFSET of an FDE in the .eh_frame section, and +// the contents of the .eh_frame section EH_FRAME_CONTENTS, where the +// FDE's encoding is FDE_ENCODING, return the output address of the +// FDE's PC. + +template<int size, bool big_endian> +typename elfcpp::Elf_types<size>::Elf_Addr +Eh_frame_hdr::get_fde_pc(const unsigned char* eh_frame_contents, + off_t fde_offset, unsigned char fde_encoding) +{ + // The FDE starts with a 4 byte length and a 4 byte offset to the + // CIE. The PC follows. + const unsigned char* p = eh_frame_contents + fde_offset + 8; + + typename elfcpp::Elf_types<size>::Elf_Addr pc; + bool is_signed = (fde_encoding & elfcpp::DW_EH_PE_signed) != 0; + int pc_size = fde_encoding & 7; + if (pc_size == elfcpp::DW_EH_PE_absptr) + { + if (size == 32) + pc_size = elfcpp::DW_EH_PE_udata4; + else if (size == 64) + pc_size = elfcpp::DW_EH_PE_udata8; + else + gold_unreachable(); + } + + switch (pc_size) + { + case elfcpp::DW_EH_PE_udata2: + pc = elfcpp::Swap<16, big_endian>::readval(p); + if (is_signed) + pc = (pc ^ 0x8000) - 0x8000; + break; + + case elfcpp::DW_EH_PE_udata4: + pc = elfcpp::Swap<32, big_endian>::readval(p); + if (size > 32 && is_signed) + pc = (pc ^ 0x80000000) - 0x80000000; + break; + + case elfcpp::DW_EH_PE_udata8: + gold_assert(size == 64); + pc = elfcpp::Swap_unaligned<64, big_endian>::readval(p); + break; + + default: + gold_unreachable(); + } + + return pc; +} + +// Given an array of FDE offsets in the .eh_frame section, return an +// array of offsets from the exception frame header to the FDE's +// output PC and to the output address of the FDE itself. We get the +// FDE's PC by actually looking in the .eh_frame section we just wrote +// to the output file. + +template<int size, bool big_endian> +void +Eh_frame_hdr::get_fde_addresses(Output_file* of, + const Fde_offsets* fde_offsets, + Fde_addresses<size>* fde_addresses) +{ + typename elfcpp::Elf_types<size>::Elf_Addr eh_frame_address; + eh_frame_address = this->eh_frame_section_->address(); + off_t eh_frame_offset = this->eh_frame_section_->offset(); + off_t eh_frame_size = this->eh_frame_section_->data_size(); + const unsigned char* eh_frame_contents = of->get_input_view(eh_frame_offset, + eh_frame_size); + + for (Fde_offsets::const_iterator p = fde_offsets->begin(); + p != fde_offsets->end(); + ++p) + { + typename elfcpp::Elf_types<size>::Elf_Addr fde_pc; + fde_pc = this->get_fde_pc<size, big_endian>(eh_frame_contents, + p->first, p->second); + fde_addresses->push_back(fde_pc, eh_frame_address + p->first); + } + + of->free_input_view(eh_frame_offset, eh_frame_size, eh_frame_contents); +} + +// Class Fde. + +// Write the FDE to OVIEW starting at OFFSET. CIE_OFFSET is the +// offset of the CIE in OVIEW. FDE_ENCODING is the encoding, from the +// CIE. Record the FDE pc for EH_FRAME_HDR. Return the new offset. + +template<int size, bool big_endian> +off_t +Fde::write(unsigned char* oview, off_t offset, off_t cie_offset, + unsigned char fde_encoding, Eh_frame_hdr* eh_frame_hdr) +{ + size_t length = this->contents_.length(); + + // Write the length of the FDE as a 32-bit word. The length word + // does not include the four bytes of the length word itself, but it + // does include the offset to the CIE. + elfcpp::Swap<32, big_endian>::writeval(oview + offset, + length + 4); + + // Write the offset to the CIE as a 32-bit word. This is the + // difference between the address of the offset word itself and the + // CIE address. + elfcpp::Swap<32, big_endian>::writeval(oview + offset + 4, + offset + 4 - cie_offset); + + // Copy the rest of the FDE. Note that this is run before + // relocation processing is done on this section, so the relocations + // will later be applied to the FDE data. + memcpy(oview + offset + 8, this->contents_.data(), length); + + // Tell the exception frame header about this FDE. + if (eh_frame_hdr != NULL) + eh_frame_hdr->record_fde(offset, fde_encoding); + + return offset + length + 8; +} + +// Class Cie. + +// Destructor. + +Cie::~Cie() +{ + for (std::vector<Fde*>::iterator p = this->fdes_.begin(); + p != this->fdes_.end(); + ++p) + delete *p; +} + +// Set the output offset of a CIE. Return the new output offset. + +off_t +Cie::set_output_offset(off_t output_offset, unsigned int addralign, + Merge_map* merge_map) +{ + size_t length = this->contents_.length(); + gold_assert((length & (addralign - 1)) == 0); + // Add 4 for length and 4 for zero CIE identifier tag. + length += 8; + + merge_map->add_mapping(this->object_, this->shndx_, this->input_offset_, + length, output_offset); + + for (std::vector<Fde*>::const_iterator p = this->fdes_.begin(); + p != this->fdes_.end(); + ++p) + { + (*p)->add_mapping(output_offset + length, merge_map); + + size_t fde_length = (*p)->length(); + gold_assert((fde_length & (addralign - 1)) == 0); + length += fde_length; + } + + return output_offset + length; +} + +// Write the CIE to OVIEW starting at OFFSET. EH_FRAME_HDR is for FDE +// recording. Return the new offset. + +template<int size, bool big_endian> +off_t +Cie::write(unsigned char* oview, off_t offset, Eh_frame_hdr* eh_frame_hdr) +{ + off_t cie_offset = offset; + + size_t length = this->contents_.length(); + + // Write the length of the CIE as a 32-bit word. The length word + // does not include the four bytes of the length word itself. + elfcpp::Swap<32, big_endian>::writeval(oview + offset, length + 4); + + // Write the tag which marks this as a CIE: a 32-bit zero. + elfcpp::Swap<32, big_endian>::writeval(oview + offset + 4, 0); + + // Write out the CIE data. + memcpy(oview + offset + 8, this->contents_.data(), length); + offset += length + 8; + + // Write out the associated FDEs. + unsigned char fde_encoding = this->fde_encoding_; + for (std::vector<Fde*>::const_iterator p = this->fdes_.begin(); + p != this->fdes_.end(); + ++p) + offset = (*p)->write<size, big_endian>(oview, offset, cie_offset, + fde_encoding, eh_frame_hdr); + + return offset; +} + +// We track all the CIEs we see, and merge them when possible. This +// works because each FDE holds an offset to the relevant CIE: we +// rewrite the FDEs to point to the merged CIE. This is worthwhile +// because in a typical C++ program many FDEs in many different object +// files will use the same CIE. + +// An equality operator for Cie. + +bool +operator==(const Cie& cie1, const Cie& cie2) +{ + return (cie1.personality_name_ == cie2.personality_name_ + && cie1.contents_ == cie2.contents_); +} + +// A less-than operator for Cie. + +bool +operator<(const Cie& cie1, const Cie& cie2) +{ + if (cie1.personality_name_ != cie2.personality_name_) + return cie1.personality_name_ < cie2.personality_name_; + return cie1.contents_ < cie2.contents_; +} + +// Class Eh_frame. + +Eh_frame::Eh_frame() + : Output_section_data(Output_data::default_alignment()), + eh_frame_hdr_(NULL), + cie_offsets_(), + unmergeable_cie_offsets_(), + merge_map_() +{ +} + +// Skip an LEB128, updating *PP to point to the next character. +// Return false if we ran off the end of the string. + +bool +Eh_frame::skip_leb128(const unsigned char** pp, const unsigned char* pend) +{ + const unsigned char* p; + for (p = *pp; p < pend; ++p) + { + if ((*p & 0x80) == 0) + { + *pp = p + 1; + return true; + } + } + return false; +} + +// Add input section SHNDX in OBJECT to an exception frame section. +// SYMBOLS is the contents of the symbol table section (size +// SYMBOLS_SIZE), SYMBOL_NAMES is the symbol names section (size +// SYMBOL_NAMES_SIZE). RELOC_SHNDX is the index of a relocation +// section applying to SHNDX, or 0 if none, or -1U if more than one. +// RELOC_TYPE is the type of the reloc section if there is one, either +// SHT_REL or SHT_RELA. We try to parse the input exception frame +// data into our data structures. If we can't do it, we return false +// to mean that the section should be handled as a normal input +// section. + +template<int size, bool big_endian> +bool +Eh_frame::add_ehframe_input_section( + Sized_relobj<size, big_endian>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type) +{ + // Get the section contents. + off_t contents_len; + const unsigned char* pcontents = object->section_contents(shndx, + &contents_len, + false); + if (contents_len == 0) + return false; + + // If this is the marker section for the end of the data, then + // return false to force it to be handled as an ordinary input + // section. If we don't do this, we won't correctly handle the case + // of unrecognized .eh_frame sections. + if (contents_len == 4 + && elfcpp::Swap<32, big_endian>::readval(pcontents) == 0) + return false; + + New_cies new_cies; + if (!this->do_add_ehframe_input_section(object, symbols, symbols_size, + symbol_names, symbol_names_size, + shndx, reloc_shndx, + reloc_type, pcontents, + contents_len, &new_cies)) + { + this->eh_frame_hdr_->found_unrecognized_eh_frame_section(); + + for (New_cies::iterator p = new_cies.begin(); + p != new_cies.end(); + ++p) + delete p->first; + + return false; + } + + // Now that we know we are using this section, record any new CIEs + // that we found. + for (New_cies::const_iterator p = new_cies.begin(); + p != new_cies.end(); + ++p) + { + uint64_t zero = 0; + if (p->second) + this->cie_offsets_.insert(std::make_pair(p->first, zero)); + else + this->unmergeable_cie_offsets_.push_back(std::make_pair(p->first, + zero)); + } + + return true; +} + +// The bulk of the implementation of add_ehframe_input_section. + +template<int size, bool big_endian> +bool +Eh_frame::do_add_ehframe_input_section( + Sized_relobj<size, big_endian>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type, + const unsigned char* pcontents, + off_t contents_len, + New_cies* new_cies) +{ + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + Track_relocs<size, big_endian> relocs; + + const unsigned char* p = pcontents; + const unsigned char* pend = p + contents_len; + + // Get the contents of the reloc section if any. + if (!relocs.initialize(object, reloc_shndx, reloc_type)) + return false; + + // Keep track of which CIEs are at which offsets. + Offsets_to_cie cies; + + while (p < pend) + { + if (pend - p < 4) + return false; + + // There shouldn't be any relocations here. + if (relocs.advance(p + 4 - pcontents) > 0) + return false; + + unsigned int len = elfcpp::Swap<32, big_endian>::readval(p); + p += 4; + if (len == 0) + { + // We should only find a zero-length entry at the end of the + // section. + if (p < pend) + return false; + break; + } + // We don't support a 64-bit .eh_frame. + if (len == 0xffffffff) + return false; + if (static_cast<unsigned int>(pend - p) < len) + return false; + + const unsigned char* const pentend = p + len; + + if (pend - p < 4) + return false; + if (relocs.advance(p + 4 - pcontents) > 0) + return false; + + unsigned int id = elfcpp::Swap<32, big_endian>::readval(p); + p += 4; + + if (id == 0) + { + // CIE. + if (!this->read_cie(object, shndx, symbols, symbols_size, + symbol_names, symbol_names_size, + pcontents, p, pentend, &relocs, &cies, + new_cies)) + return false; + } + else + { + // FDE. + if (!this->read_fde(object, shndx, symbols, symbols_size, + pcontents, id, p, pentend, &relocs, &cies)) + return false; + } + + p = pentend; + } + + return true; +} + +// Read a CIE. Return false if we can't parse the information. + +template<int size, bool big_endian> +bool +Eh_frame::read_cie(Sized_relobj<size, big_endian>* object, + unsigned int shndx, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + const unsigned char* pcontents, + const unsigned char* pcie, + const unsigned char *pcieend, + Track_relocs<size, big_endian>* relocs, + Offsets_to_cie* cies, + New_cies* new_cies) +{ + bool mergeable = true; + + // We need to find the personality routine if there is one, since we + // can only merge CIEs which use the same routine. We also need to + // find the FDE encoding if there is one, so that we can read the PC + // from the FDE. + + const unsigned char* p = pcie; + + if (pcieend - p < 1) + return false; + unsigned char version = *p++; + if (version != 1 && version != 3) + return false; + + const unsigned char* paug = p; + const void* paugendv = memchr(p, '\0', pcieend - p); + const unsigned char* paugend = static_cast<const unsigned char*>(paugendv); + if (paugend == NULL) + return false; + p = paugend + 1; + + if (paug[0] == 'e' && paug[1] == 'h') + { + // This is a CIE from gcc before version 3.0. We can't merge + // these. We can still read the FDEs. + mergeable = false; + paug += 2; + if (*paug != '\0') + return false; + if (pcieend - p < size / 8) + return false; + p += size / 8; + } + + // Skip the code alignment. + if (!skip_leb128(&p, pcieend)) + return false; + + // Skip the data alignment. + if (!skip_leb128(&p, pcieend)) + return false; + + // Skip the return column. + if (version == 1) + { + if (pcieend - p < 1) + return false; + ++p; + } + else + { + if (!skip_leb128(&p, pcieend)) + return false; + } + + if (*paug == 'z') + { + ++paug; + // Skip the augmentation size. + if (!skip_leb128(&p, pcieend)) + return false; + } + + unsigned char fde_encoding = elfcpp::DW_EH_PE_absptr; + int per_offset = -1; + while (*paug != '\0') + { + switch (*paug) + { + case 'L': // LSDA encoding. + if (pcieend - p < 1) + return false; + ++p; + break; + + case 'R': // FDE encoding. + if (pcieend - p < 1) + return false; + fde_encoding = *p; + switch (fde_encoding & 7) + { + case elfcpp::DW_EH_PE_absptr: + case elfcpp::DW_EH_PE_udata2: + case elfcpp::DW_EH_PE_udata4: + case elfcpp::DW_EH_PE_udata8: + break; + default: + return false; + } + ++p; + break; + + case 'S': + break; + + case 'P': + // Personality encoding. + { + if (pcieend - p < 1) + return false; + unsigned char per_encoding = *p; + ++p; + + if ((per_encoding & 0x60) == 0x60) + return false; + unsigned int per_width; + switch (per_encoding & 7) + { + case elfcpp::DW_EH_PE_udata2: + per_width = 2; + break; + case elfcpp::DW_EH_PE_udata4: + per_width = 4; + break; + case elfcpp::DW_EH_PE_udata8: + per_width = 8; + break; + case elfcpp::DW_EH_PE_absptr: + per_width = size / 8; + break; + default: + return false; + } + + if ((per_encoding & 0xf0) == elfcpp::DW_EH_PE_aligned) + { + unsigned int len = p - pcie; + len += per_width - 1; + len &= ~ (per_width - 1); + if (static_cast<unsigned int>(pcieend - p) < len) + return false; + p += len; + } + + per_offset = p - pcontents; + + if (static_cast<unsigned int>(pcieend - p) < per_width) + return false; + p += per_width; + } + break; + + default: + return false; + } + + ++paug; + } + + const char* personality_name = ""; + if (per_offset != -1) + { + if (relocs->advance(per_offset) > 0) + return false; + if (relocs->next_offset() != per_offset) + return false; + + unsigned int personality_symndx = relocs->next_symndx(); + if (personality_symndx == -1U) + return false; + + if (personality_symndx < object->local_symbol_count()) + { + // We can only merge this CIE if the personality routine is + // a global symbol. We can still read the FDEs. + mergeable = false; + } + else + { + const int sym_size = elfcpp::Elf_sizes<size>::sym_size; + if (personality_symndx >= symbols_size / sym_size) + return false; + elfcpp::Sym<size, big_endian> sym(symbols + + (personality_symndx * sym_size)); + unsigned int name_offset = sym.get_st_name(); + if (name_offset >= symbol_names_size) + return false; + personality_name = (reinterpret_cast<const char*>(symbol_names) + + name_offset); + } + + int r = relocs->advance(per_offset + 1); + gold_assert(r == 1); + } + + if (relocs->advance(pcieend - pcontents) > 0) + return false; + + Cie cie(object, shndx, (pcie - 8) - pcontents, fde_encoding, + personality_name, pcie, pcieend - pcie); + Cie* cie_pointer = NULL; + if (mergeable) + { + Cie_offsets::iterator find_cie = this->cie_offsets_.find(&cie); + if (find_cie != this->cie_offsets_.end()) + cie_pointer = find_cie->first; + else + { + // See if we already saw this CIE in this object file. + for (New_cies::const_iterator pc = new_cies->begin(); + pc != new_cies->end(); + ++pc) + { + if (*(pc->first) == cie) + { + cie_pointer = pc->first; + break; + } + } + } + } + + if (cie_pointer == NULL) + { + cie_pointer = new Cie(cie); + new_cies->push_back(std::make_pair(cie_pointer, mergeable)); + } + else + { + // We are deleting this CIE. Record that in our mapping from + // input sections to the output section. At this point we don't + // know for sure that we are doing a special mapping for this + // input section, but that's OK--if we don't do a special + // mapping, nobody will ever ask for the mapping we add here. + this->merge_map_.add_mapping(object, shndx, (pcie - 8) - pcontents, + pcieend - (pcie - 8), -1); + } + + // Record this CIE plus the offset in the input section. + cies->insert(std::make_pair(pcie - pcontents, cie_pointer)); + + return true; +} + +// Read an FDE. Return false if we can't parse the information. + +template<int size, bool big_endian> +bool +Eh_frame::read_fde(Sized_relobj<size, big_endian>* object, + unsigned int shndx, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* pcontents, + unsigned int offset, + const unsigned char* pfde, + const unsigned char *pfdeend, + Track_relocs<size, big_endian>* relocs, + Offsets_to_cie* cies) +{ + // OFFSET is the distance between the 4 bytes before PFDE to the + // start of the CIE. The offset we recorded for the CIE is 8 bytes + // after the start of the CIE--after the length and the zero tag. + unsigned int cie_offset = (pfde - 4 - pcontents) - offset + 8; + Offsets_to_cie::const_iterator pcie = cies->find(cie_offset); + if (pcie == cies->end()) + return false; + Cie* cie = pcie->second; + + // The FDE should start with a reloc to the start of the code which + // it describes. + if (relocs->advance(pfde - pcontents) > 0) + return false; + + if (relocs->next_offset() != pfde - pcontents) + return false; + + unsigned int symndx = relocs->next_symndx(); + if (symndx == -1U) + return false; + + // There can be another reloc in the FDE, if the CIE specifies an + // LSDA (language specific data area). We currently don't care. We + // will care later if we want to optimize the LSDA from an absolute + // pointer to a PC relative offset when generating a shared library. + relocs->advance(pfdeend - pcontents); + + unsigned int fde_shndx; + const int sym_size = elfcpp::Elf_sizes<size>::sym_size; + if (symndx >= symbols_size / sym_size) + return false; + elfcpp::Sym<size, big_endian> sym(symbols + symndx * sym_size); + fde_shndx = sym.get_st_shndx(); + + if (fde_shndx != elfcpp::SHN_UNDEF + && fde_shndx < object->shnum() + && !object->is_section_included(fde_shndx)) + { + // This FDE applies to a section which we are discarding. We + // can discard this FDE. + this->merge_map_.add_mapping(object, shndx, (pfde - 8) - pcontents, + pfdeend - (pfde - 8), -1); + return true; + } + + cie->add_fde(new Fde(object, shndx, (pfde - 8) - pcontents, + pfde, pfdeend - pfde)); + + return true; +} + +// Return the number of FDEs. + +unsigned int +Eh_frame::fde_count() const +{ + unsigned int ret = 0; + for (Unmergeable_cie_offsets::const_iterator p = + this->unmergeable_cie_offsets_.begin(); + p != this->unmergeable_cie_offsets_.end(); + ++p) + ret += p->first->fde_count(); + for (Cie_offsets::const_iterator p = this->cie_offsets_.begin(); + p != this->cie_offsets_.end(); + ++p) + ret += p->first->fde_count(); + return ret; +} + +// Set the final data size. + +void +Eh_frame::do_set_address(uint64_t, off_t start_file_offset) +{ + off_t output_offset = 0; + + for (Unmergeable_cie_offsets::iterator p = + this->unmergeable_cie_offsets_.begin(); + p != this->unmergeable_cie_offsets_.end(); + ++p) + { + p->second = start_file_offset + output_offset; + output_offset = p->first->set_output_offset(output_offset, + this->addralign(), + &this->merge_map_); + } + + for (Cie_offsets::iterator p = this->cie_offsets_.begin(); + p != this->cie_offsets_.end(); + ++p) + { + p->second = start_file_offset + output_offset; + output_offset = p->first->set_output_offset(output_offset, + this->addralign(), + &this->merge_map_); + } + + gold_assert((output_offset & (this->addralign() - 1)) == 0); + this->set_data_size(output_offset); +} + +// Return an output offset for an input offset. + +bool +Eh_frame::do_output_offset(const Relobj* object, unsigned int shndx, + off_t offset, off_t* poutput) const +{ + return this->merge_map_.get_output_offset(object, shndx, offset, poutput); +} + +// Write the data to the output file. + +void +Eh_frame::do_write(Output_file* of) +{ + const off_t offset = this->offset(); + const off_t oview_size = this->data_size(); + unsigned char* const oview = of->get_output_view(offset, oview_size); + + if (parameters->get_size() == 32) + { + if (!parameters->is_big_endian()) + { +#ifdef HAVE_TARGET_32_LITTLE + this->do_sized_write<32, false>(oview); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_32_BIG + this->do_sized_write<32, true>(oview); +#else + gold_unreachable(); +#endif + } + } + else if (parameters->get_size() == 64) + { + if (!parameters->is_big_endian()) + { +#ifdef HAVE_TARGET_64_LITTLE + this->do_sized_write<64, false>(oview); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_64_BIG + this->do_sized_write<64, true>(oview); +#else + gold_unreachable(); +#endif + } + } + else + gold_unreachable(); + + of->write_output_view(offset, oview_size, oview); +} + +// Write the data to the output file--template version. + +template<int size, bool big_endian> +void +Eh_frame::do_sized_write(unsigned char* oview) +{ + off_t o = 0; + for (Unmergeable_cie_offsets::iterator p = + this->unmergeable_cie_offsets_.begin(); + p != this->unmergeable_cie_offsets_.end(); + ++p) + o = p->first->write<size, big_endian>(oview, o, this->eh_frame_hdr_); + for (Cie_offsets::iterator p = this->cie_offsets_.begin(); + p != this->cie_offsets_.end(); + ++p) + o = p->first->write<size, big_endian>(oview, o, this->eh_frame_hdr_); +} + +#ifdef HAVE_TARGET_32_LITTLE +template +bool +Eh_frame::add_ehframe_input_section<32, false>( + Sized_relobj<32, false>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + +#ifdef HAVE_TARGET_32_BIG +template +bool +Eh_frame::add_ehframe_input_section<32, true>( + Sized_relobj<32, true>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + +#ifdef HAVE_TARGET_64_LITTLE +template +bool +Eh_frame::add_ehframe_input_section<64, false>( + Sized_relobj<64, false>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + +#ifdef HAVE_TARGET_64_BIG +template +bool +Eh_frame::add_ehframe_input_section<64, true>( + Sized_relobj<64, true>* object, + const unsigned char* symbols, + off_t symbols_size, + const unsigned char* symbol_names, + off_t symbol_names_size, + unsigned int shndx, + unsigned int reloc_shndx, + unsigned int reloc_type); +#endif + } // End namespace gold. |