Merge branch 'vendor/GCC44'
[dragonfly.git] / contrib / binutils-2.21 / gold / binary.cc
1 // binary.cc -- binary input files for gold
2
3 // Copyright 2008 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
5
6 // This file is part of gold.
7
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
12
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
22
23 #include "gold.h"
24
25 #include <cerrno>
26 #include <cstring>
27 #include "safe-ctype.h"
28
29 #include "elfcpp.h"
30 #include "stringpool.h"
31 #include "fileread.h"
32 #include "output.h"
33 #include "binary.h"
34
35 // Support for reading binary files as input.  These become blobs in
36 // the final output.  These files are treated as though they have a
37 // single .data section and define three symbols:
38 // _binary_FILENAME_start, _binary_FILENAME_end, _binary_FILENAME_size.
39 // The FILENAME is the name of the input file, with any
40 // non-alphanumeric character changed to an underscore.
41
42 // We implement this by creating an ELF file in memory.
43
44 namespace gold
45 {
46
47 // class Binary_to_elf.
48
49 Binary_to_elf::Binary_to_elf(elfcpp::EM machine, int size, bool big_endian,
50                              const std::string& filename)
51   : elf_machine_(machine), size_(size), big_endian_(big_endian),
52     filename_(filename), data_(NULL), filesize_(0)
53 {
54 }
55
56 Binary_to_elf::~Binary_to_elf()
57 {
58   if (this->data_ != NULL)
59     delete[] this->data_;
60 }
61
62 // Given FILENAME, create a buffer which looks like an ELF file with
63 // the contents of FILENAME as the contents of the only section.  The
64 // TASK parameters is mainly for debugging, and records who holds
65 // locks.
66
67 bool
68 Binary_to_elf::convert(const Task* task)
69 {
70   if (this->size_ == 32)
71     {
72       if (!this->big_endian_)
73         {
74 #ifdef HAVE_TARGET_32_LITTLE
75           return this->sized_convert<32, false>(task);
76 #else
77           gold_unreachable();
78 #endif
79         }
80       else
81         {
82 #ifdef HAVE_TARGET_32_BIG
83           return this->sized_convert<32, true>(task);
84 #else
85           gold_unreachable();
86 #endif
87         }
88     }
89   else if (this->size_ == 64)
90     {
91       if (!this->big_endian_)
92         {
93 #ifdef HAVE_TARGET_64_LITTLE
94           return this->sized_convert<64, false>(task);
95 #else
96           gold_unreachable();
97 #endif
98         }
99       else
100         {
101 #ifdef HAVE_TARGET_64_BIG
102           return this->sized_convert<64, true>(task);
103 #else
104           gold_unreachable();
105 #endif
106         }
107     }
108   else
109     gold_unreachable();
110 }
111
112 // We are going to create:
113 // * The ELF file header.
114 // * Five sections: null section, .data, .symtab, .strtab, .shstrtab
115 // * The contents of the file.
116 // * Four symbols: null, begin, end, size.
117 // * Three symbol names.
118 // * Four section names.
119
120 template<int size, bool big_endian>
121 bool
122 Binary_to_elf::sized_convert(const Task* task)
123 {
124   // Read the input file.
125
126   File_read f;
127   if (!f.open(task, this->filename_))
128     {
129       gold_error(_("cannot open %s: %s:"), this->filename_.c_str(),
130                  strerror(errno));
131       return false;
132     }
133
134   section_size_type filesize = convert_to_section_size_type(f.filesize());
135   const unsigned char* fileview;
136   if (filesize == 0)
137     fileview = NULL;
138   else
139     fileview = f.get_view(0, 0, filesize, false, false);
140
141   unsigned int align;
142   if (size == 32)
143     align = 4;
144   else if (size == 64)
145     align = 8;
146   else
147     gold_unreachable();
148   section_size_type aligned_filesize = align_address(filesize, align);
149
150   // Build the stringpool for the symbol table.
151
152   std::string mangled_name = this->filename_;
153   for (std::string::iterator p = mangled_name.begin();
154        p != mangled_name.end();
155        ++p)
156     if (!ISALNUM(*p))
157       *p = '_';
158   mangled_name = "_binary_" + mangled_name;
159   std::string start_symbol_name = mangled_name + "_start";
160   std::string end_symbol_name = mangled_name + "_end";
161   std::string size_symbol_name = mangled_name + "_size";
162
163   Stringpool strtab;
164   strtab.add(start_symbol_name.c_str(), false, NULL);
165   strtab.add(end_symbol_name.c_str(), false, NULL);
166   strtab.add(size_symbol_name.c_str(), false, NULL);
167   strtab.set_string_offsets();
168
169   // Build the stringpool for the section name table.
170
171   Stringpool shstrtab;
172   shstrtab.add(".data", false, NULL);
173   shstrtab.add(".symtab", false, NULL);
174   shstrtab.add(".strtab", false, NULL);
175   shstrtab.add(".shstrtab", false, NULL);
176   shstrtab.set_string_offsets();
177
178   // Work out the size of the generated file, and the offsets of the
179   // various sections, and allocate a buffer.
180
181   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
182
183   size_t output_size = (elfcpp::Elf_sizes<size>::ehdr_size
184                         + 5 * elfcpp::Elf_sizes<size>::shdr_size);
185   size_t data_offset = output_size;
186   output_size += aligned_filesize;
187   size_t symtab_offset = output_size;
188   output_size += 4 * sym_size;
189   size_t strtab_offset = output_size;
190   output_size += strtab.get_strtab_size();
191   size_t shstrtab_offset = output_size;
192   output_size += shstrtab.get_strtab_size();
193
194   unsigned char* buffer = new unsigned char[output_size];
195
196   // Write out the data.
197
198   unsigned char* pout = buffer;
199
200   this->write_file_header<size, big_endian>(&pout);
201
202   this->write_section_header<size, big_endian>("", &shstrtab, elfcpp::SHT_NULL,
203                                                0, 0, 0, 0, 0,
204                                                0, 0, &pout);
205   // Having the section be named ".data", having it be writable, and
206   // giving it an alignment of 1 is because the GNU linker does it
207   // that way, and existing linker script expect it.
208   this->write_section_header<size, big_endian>(".data", &shstrtab,
209                                                elfcpp::SHT_PROGBITS,
210                                                (elfcpp::SHF_ALLOC
211                                                 | elfcpp::SHF_WRITE),
212                                                data_offset,
213                                                filesize, 0, 0,
214                                                1, 0, &pout);
215   this->write_section_header<size, big_endian>(".symtab", &shstrtab,
216                                                elfcpp::SHT_SYMTAB,
217                                                0, symtab_offset, 4 * sym_size,
218                                                3, 1, align, sym_size, &pout);
219   this->write_section_header<size, big_endian>(".strtab", &shstrtab,
220                                                elfcpp::SHT_STRTAB,
221                                                0, strtab_offset,
222                                                strtab.get_strtab_size(),
223                                                0, 0, 1, 0, &pout);
224   this->write_section_header<size, big_endian>(".shstrtab", &shstrtab,
225                                                elfcpp::SHT_STRTAB,
226                                                0, shstrtab_offset,
227                                                shstrtab.get_strtab_size(),
228                                                0, 0, 1, 0, &pout);
229
230   if (filesize > 0)
231     {
232       memcpy(pout, fileview, filesize);
233       pout += filesize;
234       memset(pout, 0, aligned_filesize - filesize);
235       pout += aligned_filesize - filesize;
236     }
237
238   this->write_symbol<size, big_endian>("", &strtab, 0, 0, &pout);
239   this->write_symbol<size, big_endian>(start_symbol_name, &strtab, 0, 1,
240                                        &pout);
241   this->write_symbol<size, big_endian>(end_symbol_name, &strtab, filesize, 1,
242                                        &pout);
243   this->write_symbol<size, big_endian>(size_symbol_name, &strtab, filesize,
244                                        elfcpp::SHN_ABS, &pout);
245
246   strtab.write_to_buffer(pout, strtab.get_strtab_size());
247   pout += strtab.get_strtab_size();
248
249   shstrtab.write_to_buffer(pout, shstrtab.get_strtab_size());
250   pout += shstrtab.get_strtab_size();
251
252   gold_assert(static_cast<size_t>(pout - buffer) == output_size);
253
254   this->data_ = buffer;
255   this->filesize_ = output_size;
256
257   f.unlock(task);
258
259   return true;
260 }
261
262 // Write out the file header.
263
264 template<int size, bool big_endian>
265 void
266 Binary_to_elf::write_file_header(unsigned char** ppout)
267 {
268   elfcpp::Ehdr_write<size, big_endian> oehdr(*ppout);
269
270   unsigned char e_ident[elfcpp::EI_NIDENT];
271   memset(e_ident, 0, elfcpp::EI_NIDENT);
272   e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
273   e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
274   e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
275   e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
276   if (size == 32)
277     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
278   else if (size == 64)
279     e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
280   else
281     gold_unreachable();
282   e_ident[elfcpp::EI_DATA] = (big_endian
283                               ? elfcpp::ELFDATA2MSB
284                               : elfcpp::ELFDATA2LSB);
285   e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
286   oehdr.put_e_ident(e_ident);
287
288   oehdr.put_e_type(elfcpp::ET_REL);
289   oehdr.put_e_machine(this->elf_machine_);
290   oehdr.put_e_version(elfcpp::EV_CURRENT);
291   oehdr.put_e_entry(0);
292   oehdr.put_e_phoff(0);
293   oehdr.put_e_shoff(elfcpp::Elf_sizes<size>::ehdr_size);
294   oehdr.put_e_flags(0);
295   oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
296   oehdr.put_e_phentsize(0);
297   oehdr.put_e_phnum(0);
298   oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
299   oehdr.put_e_shnum(5);
300   oehdr.put_e_shstrndx(4);
301
302   *ppout += elfcpp::Elf_sizes<size>::ehdr_size;
303 }
304
305 // Write out a section header.
306
307 template<int size, bool big_endian>
308 void
309 Binary_to_elf::write_section_header(
310     const char* name,
311     const Stringpool* shstrtab,
312     elfcpp::SHT type,
313     unsigned int flags,
314     section_size_type offset,
315     section_size_type section_size,
316     unsigned int link,
317     unsigned int info,
318     unsigned int addralign,
319     unsigned int entsize,
320     unsigned char** ppout)
321 {
322   elfcpp::Shdr_write<size, big_endian> oshdr(*ppout);
323
324   oshdr.put_sh_name(*name == '\0' ? 0 : shstrtab->get_offset(name));
325   oshdr.put_sh_type(type);
326   oshdr.put_sh_flags(flags);
327   oshdr.put_sh_addr(0);
328   oshdr.put_sh_offset(offset);
329   oshdr.put_sh_size(section_size);
330   oshdr.put_sh_link(link);
331   oshdr.put_sh_info(info);
332   oshdr.put_sh_addralign(addralign);
333   oshdr.put_sh_entsize(entsize);
334
335   *ppout += elfcpp::Elf_sizes<size>::shdr_size;
336 }
337
338 // Write out a symbol.
339
340 template<int size, bool big_endian>
341 void
342 Binary_to_elf::write_symbol(
343     const std::string& name,
344     const Stringpool* strtab,
345     section_size_type value,
346     unsigned int shndx,
347     unsigned char** ppout)
348 {
349   unsigned char* pout = *ppout;
350
351   elfcpp::Sym_write<size, big_endian> osym(pout);
352   osym.put_st_name(name.empty() ? 0 : strtab->get_offset(name.c_str()));
353   osym.put_st_value(value);
354   osym.put_st_size(0);
355   osym.put_st_info(name.empty() ? elfcpp::STB_LOCAL : elfcpp::STB_GLOBAL,
356                    elfcpp::STT_NOTYPE);
357   osym.put_st_other(elfcpp::STV_DEFAULT, 0);
358   osym.put_st_shndx(shndx);
359
360   *ppout += elfcpp::Elf_sizes<size>::sym_size;
361 }
362
363 } // End namespace gold.