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authorIan Lance Taylor <iant@google.com>2008-02-08 07:06:58 +0000
committerIan Lance Taylor <iant@google.com>2008-02-08 07:06:58 +0000
commitbc644c6cfca852cd34e486a018bfde7fd1ac55e8 (patch)
tree0a3f5a7539df0cebdaddc0accf07a156e5c5221c /gold/binary.cc
parent897b09ca9f17a38ab9c552ae6933eb595283aa4c (diff)
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Add support for --format binary for input files.
Diffstat (limited to 'gold/binary.cc')
-rw-r--r--gold/binary.cc356
1 files changed, 356 insertions, 0 deletions
diff --git a/gold/binary.cc b/gold/binary.cc
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+// binary.cc -- binary input files for gold
+
+// Copyright 2008 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// 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 <cerrno>
+#include <cstring>
+#include "safe-ctype.h"
+
+#include "elfcpp.h"
+#include "stringpool.h"
+#include "fileread.h"
+#include "output.h"
+#include "binary.h"
+
+// Support for reading binary files as input. These become blobs in
+// the final output. These files are treated as though they have a
+// single .data section and define three symbols:
+// _binary_FILENAME_start, _binary_FILENAME_end, _binary_FILENAME_end.
+// The FILENAME is the name of the input file, with any
+// non-alphanumeric character changed to an underscore.
+
+// We implement this by creating an ELF file in memory.
+
+namespace gold
+{
+
+// class Binary_to_elf.
+
+Binary_to_elf::Binary_to_elf(elfcpp::EM machine, int size, bool big_endian,
+ const std::string& filename)
+ : elf_machine_(machine), size_(size), big_endian_(big_endian),
+ filename_(filename), data_(NULL), filesize_(0)
+{
+}
+
+Binary_to_elf::~Binary_to_elf()
+{
+ if (this->data_ != NULL)
+ delete[] this->data_;
+}
+
+// Given FILENAME, create a buffer which looks like an ELF file with
+// the contents of FILENAME as the contents of the only section. The
+// TASK parameters is mainly for debugging, and records who holds
+// locks.
+
+bool
+Binary_to_elf::convert(const Task* task)
+{
+ if (this->size_ == 32)
+ {
+ if (!this->big_endian_)
+ {
+#ifdef HAVE_TARGET_32_LITTLE
+ return this->sized_convert<32, false>(task);
+#else
+ gold_unreachable();
+#endif
+ }
+ else
+ {
+#ifdef HAVE_TARGET_32_BIG
+ return this->sized_convert<32, true>(task);
+#else
+ gold_unreachable();
+#endif
+ }
+ }
+ else if (this->size_ == 64)
+ {
+ if (!this->big_endian_)
+ {
+#ifdef HAVE_TARGET_64_LITTLE
+ return this->sized_convert<64, false>(task);
+#else
+ gold_unreachable();
+#endif
+ }
+ else
+ {
+#ifdef HAVE_TARGET_64_BIG
+ return this->sized_convert<64, true>(task);
+#else
+ gold_unreachable();
+#endif
+ }
+ }
+ else
+ gold_unreachable();
+}
+
+// We are going to create:
+// * The ELF file header.
+// * Five sections: null section, .data, .symtab, .strtab, .shstrtab
+// * The contents of the file.
+// * Four symbols: null, begin, end, size.
+// * Three symbol names.
+// * Four section names.
+
+template<int size, bool big_endian>
+bool
+Binary_to_elf::sized_convert(const Task* task)
+{
+ // Read the input file.
+
+ File_read f;
+ if (!f.open(task, this->filename_))
+ {
+ gold_error(_("cannot open %s: %s:"), this->filename_.c_str(),
+ strerror(errno));
+ return false;
+ }
+
+ section_size_type filesize = convert_to_section_size_type(f.filesize());
+ const unsigned char* fileview = f.get_view(0, filesize, false);
+
+ unsigned int align;
+ if (size == 32)
+ align = 4;
+ else if (size == 64)
+ align = 8;
+ else
+ gold_unreachable();
+ section_size_type aligned_filesize = align_address(filesize, align);
+
+ // Build the stringpool for the symbol table.
+
+ std::string mangled_name = this->filename_;
+ for (std::string::iterator p = mangled_name.begin();
+ p != mangled_name.end();
+ ++p)
+ if (!ISALNUM(*p))
+ *p = '_';
+ mangled_name = "_binary_" + mangled_name;
+ std::string start_symbol_name = mangled_name + "_start";
+ std::string end_symbol_name = mangled_name + "_end";
+ std::string size_symbol_name = mangled_name + "_size";
+
+ Stringpool strtab;
+ strtab.add(start_symbol_name.c_str(), false, NULL);
+ strtab.add(end_symbol_name.c_str(), false, NULL);
+ strtab.add(size_symbol_name.c_str(), false, NULL);
+ strtab.set_string_offsets();
+
+ // Build the stringpool for the section name table.
+
+ Stringpool shstrtab;
+ shstrtab.add(".data", false, NULL);
+ shstrtab.add(".symtab", false, NULL);
+ shstrtab.add(".strtab", false, NULL);
+ shstrtab.add(".shstrtab", false, NULL);
+ shstrtab.set_string_offsets();
+
+ // Work out the size of the generated file, and the offsets of the
+ // various sections, and allocate a buffer.
+
+ const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+
+ size_t output_size = (elfcpp::Elf_sizes<size>::ehdr_size
+ + 5 * elfcpp::Elf_sizes<size>::shdr_size);
+ size_t data_offset = output_size;
+ output_size += aligned_filesize;
+ size_t symtab_offset = output_size;
+ output_size += 4 * sym_size;
+ size_t strtab_offset = output_size;
+ output_size += strtab.get_strtab_size();
+ size_t shstrtab_offset = output_size;
+ output_size += shstrtab.get_strtab_size();
+
+ unsigned char* buffer = new unsigned char[output_size];
+
+ // Write out the data.
+
+ unsigned char* pout = buffer;
+
+ this->write_file_header<size, big_endian>(&pout);
+
+ this->write_section_header<size, big_endian>("", &shstrtab, elfcpp::SHT_NULL,
+ 0, 0, 0, 0, 0,
+ 0, 0, &pout);
+ // Having the section be named ".data" and having it be writable is
+ // because th GNU linker does it that way, and existing linker
+ // script expect it.
+ this->write_section_header<size, big_endian>(".data", &shstrtab,
+ elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ data_offset,
+ filesize, 0, 0,
+ align, 0, &pout);
+ this->write_section_header<size, big_endian>(".symtab", &shstrtab,
+ elfcpp::SHT_SYMTAB,
+ 0, symtab_offset, 4 * sym_size,
+ 3, 1, align, sym_size, &pout);
+ this->write_section_header<size, big_endian>(".strtab", &shstrtab,
+ elfcpp::SHT_STRTAB,
+ 0, strtab_offset,
+ strtab.get_strtab_size(),
+ 0, 0, 1, 0, &pout);
+ this->write_section_header<size, big_endian>(".shstrtab", &shstrtab,
+ elfcpp::SHT_STRTAB,
+ 0, shstrtab_offset,
+ shstrtab.get_strtab_size(),
+ 0, 0, 1, 0, &pout);
+
+ memcpy(pout, fileview, filesize);
+ pout += filesize;
+ memset(pout, 0, aligned_filesize - filesize);
+ pout += aligned_filesize - filesize;
+
+ this->write_symbol<size, big_endian>("", &strtab, 0, 0, &pout);
+ this->write_symbol<size, big_endian>(start_symbol_name, &strtab, 0, 1,
+ &pout);
+ this->write_symbol<size, big_endian>(end_symbol_name, &strtab, filesize, 1,
+ &pout);
+ this->write_symbol<size, big_endian>(size_symbol_name, &strtab, filesize,
+ elfcpp::SHN_ABS, &pout);
+
+ strtab.write_to_buffer(pout, strtab.get_strtab_size());
+ pout += strtab.get_strtab_size();
+
+ shstrtab.write_to_buffer(pout, shstrtab.get_strtab_size());
+ pout += shstrtab.get_strtab_size();
+
+ gold_assert(static_cast<size_t>(pout - buffer) == output_size);
+
+ this->data_ = buffer;
+ this->filesize_ = output_size;
+
+ f.unlock(task);
+
+ return true;
+}
+
+// Write out the file header.
+
+template<int size, bool big_endian>
+void
+Binary_to_elf::write_file_header(unsigned char** ppout)
+{
+ elfcpp::Ehdr_write<size, big_endian> oehdr(*ppout);
+
+ unsigned char e_ident[elfcpp::EI_NIDENT];
+ memset(e_ident, 0, elfcpp::EI_NIDENT);
+ e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
+ e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
+ e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
+ e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
+ if (size == 32)
+ e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
+ else if (size == 64)
+ e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
+ else
+ gold_unreachable();
+ e_ident[elfcpp::EI_DATA] = (big_endian
+ ? elfcpp::ELFDATA2MSB
+ : elfcpp::ELFDATA2LSB);
+ e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
+ oehdr.put_e_ident(e_ident);
+
+ oehdr.put_e_type(elfcpp::ET_REL);
+ oehdr.put_e_machine(this->elf_machine_);
+ oehdr.put_e_version(elfcpp::EV_CURRENT);
+ oehdr.put_e_entry(0);
+ oehdr.put_e_phoff(0);
+ oehdr.put_e_shoff(elfcpp::Elf_sizes<size>::ehdr_size);
+ oehdr.put_e_flags(0);
+ oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
+ oehdr.put_e_phentsize(0);
+ oehdr.put_e_phnum(0);
+ oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
+ oehdr.put_e_shnum(5);
+ oehdr.put_e_shstrndx(4);
+
+ *ppout += elfcpp::Elf_sizes<size>::ehdr_size;
+}
+
+// Write out a section header.
+
+template<int size, bool big_endian>
+void
+Binary_to_elf::write_section_header(
+ const char* name,
+ const Stringpool* shstrtab,
+ elfcpp::SHT type,
+ unsigned int flags,
+ section_size_type offset,
+ section_size_type section_size,
+ unsigned int link,
+ unsigned int info,
+ unsigned int addralign,
+ unsigned int entsize,
+ unsigned char** ppout)
+{
+ elfcpp::Shdr_write<size, big_endian> oshdr(*ppout);
+
+ oshdr.put_sh_name(*name == '\0' ? 0 : shstrtab->get_offset(name));
+ oshdr.put_sh_type(type);
+ oshdr.put_sh_flags(flags);
+ oshdr.put_sh_addr(0);
+ oshdr.put_sh_offset(offset);
+ oshdr.put_sh_size(section_size);
+ oshdr.put_sh_link(link);
+ oshdr.put_sh_info(info);
+ oshdr.put_sh_addralign(addralign);
+ oshdr.put_sh_entsize(entsize);
+
+ *ppout += elfcpp::Elf_sizes<size>::shdr_size;
+}
+
+// Write out a symbol.
+
+template<int size, bool big_endian>
+void
+Binary_to_elf::write_symbol(
+ const std::string& name,
+ const Stringpool* strtab,
+ section_size_type value,
+ unsigned int shndx,
+ unsigned char** ppout)
+{
+ unsigned char* pout = *ppout;
+
+ elfcpp::Sym_write<size, big_endian> osym(pout);
+ osym.put_st_name(name.empty() ? 0 : strtab->get_offset(name.c_str()));
+ osym.put_st_value(value);
+ osym.put_st_size(0);
+ osym.put_st_info(name.empty() ? elfcpp::STB_LOCAL : elfcpp::STB_GLOBAL,
+ elfcpp::STT_NOTYPE);
+ osym.put_st_other(elfcpp::STV_DEFAULT, 0);
+ osym.put_st_shndx(shndx);
+
+ *ppout += elfcpp::Elf_sizes<size>::sym_size;
+}
+
+} // End namespace gold.