gold/reloc.h

   1 // reloc.h -- relocate input files for gold   -*- C++ -*-
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
   4 // Free Software Foundation, Inc.
   5 // Written by Ian Lance Taylor <iant@google.com>.
   6
   7 // This file is part of gold.
   8
   9 // This program is free software; you can redistribute it and/or modify
  10 // it under the terms of the GNU General Public License as published by
  11 // the Free Software Foundation; either version 3 of the License, or
  12 // (at your option) any later version.
  13
  14 // This program is distributed in the hope that it will be useful,
  15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 // GNU General Public License for more details.
  18
  19 // You should have received a copy of the GNU General Public License
  20 // along with this program; if not, write to the Free Software
  21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  22 // MA 02110-1301, USA.
  23
  24 #ifndef GOLD_RELOC_H
  25 #define GOLD_RELOC_H
  26
  27 #include <vector>
  28 #ifdef HAVE_BYTESWAP_H
  29 #include <byteswap.h>
  30 #endif
  31
  32 #include "elfcpp.h"
  33 #include "workqueue.h"
  34
  35 namespace gold
  36 {
  37
  38 class General_options;
  39 class Object;
  40 class Relobj;
  41 struct Read_relocs_data;
  42 class Symbol;
  43 class Layout;
  44 class Output_data;
  45 class Output_section;
  46
  47 template<int size>
  48 class Sized_symbol;
  49
  50 template<int size, bool big_endian>
  51 class Sized_relobj_file;
  52
  53 template<int size>
  54 class Symbol_value;
  55
  56 template<int sh_type, bool dynamic, int size, bool big_endian>
  57 class Output_data_reloc;
  58
  59 // A class to read the relocations for an object file, and then queue
  60 // up a task to see if they require any GOT/PLT/COPY relocations in
  61 // the symbol table.
  62
  63 class Read_relocs : public Task
  64 {
  65  public:
  66   //   THIS_BLOCKER and NEXT_BLOCKER are passed along to a Scan_relocs
  67   // or Gc_process_relocs task, so that they run in a deterministic
  68   // order.
  69   Read_relocs(Symbol_table* symtab, Layout* layout, Relobj* object,
  70               Task_token* this_blocker, Task_token* next_blocker)
  71     : symtab_(symtab), layout_(layout), object_(object),
  72       this_blocker_(this_blocker), next_blocker_(next_blocker)
  73   { }
  74
  75   // The standard Task methods.
  76
  77   Task_token*
  78   is_runnable();
  79
  80   void
  81   locks(Task_locker*);
  82
  83   void
  84   run(Workqueue*);
  85
  86   std::string
  87   get_name() const;
  88
  89  private:
  90   Symbol_table* symtab_;
  91   Layout* layout_;
  92   Relobj* object_;
  93   Task_token* this_blocker_;
  94   Task_token* next_blocker_;
  95 };
  96
  97 // Process the relocs to figure out which sections are garbage.
  98 // Very similar to scan relocs.
  99
 100 class Gc_process_relocs : public Task
 101 {
 102  public:
 103   // THIS_BLOCKER prevents this task from running until the previous
 104   // one is finished.  NEXT_BLOCKER prevents the next task from
 105   // running.
 106   Gc_process_relocs(Symbol_table* symtab, Layout* layout, Relobj* object,
 107                     Read_relocs_data* rd, Task_token* this_blocker,
 108                     Task_token* next_blocker)
 109     : symtab_(symtab), layout_(layout), object_(object), rd_(rd),
 110       this_blocker_(this_blocker), next_blocker_(next_blocker)
 111   { }
 112
 113   ~Gc_process_relocs();
 114
 115   // The standard Task methods.
 116
 117   Task_token*
 118   is_runnable();
 119
 120   void
 121   locks(Task_locker*);
 122
 123   void
 124   run(Workqueue*);
 125
 126   std::string
 127   get_name() const;
 128
 129  private:
 130   Symbol_table* symtab_;
 131   Layout* layout_;
 132   Relobj* object_;
 133   Read_relocs_data* rd_;
 134   Task_token* this_blocker_;
 135   Task_token* next_blocker_;
 136 };
 137
 138 // Scan the relocations for an object to see if they require any
 139 // GOT/PLT/COPY relocations.
 140
 141 class Scan_relocs : public Task
 142 {
 143  public:
 144   // THIS_BLOCKER prevents this task from running until the previous
 145   // one is finished.  NEXT_BLOCKER prevents the next task from
 146   // running.
 147   Scan_relocs(Symbol_table* symtab, Layout* layout, Relobj* object,
 148               Read_relocs_data* rd, Task_token* this_blocker,
 149               Task_token* next_blocker)
 150     : symtab_(symtab), layout_(layout), object_(object), rd_(rd),
 151       this_blocker_(this_blocker), next_blocker_(next_blocker)
 152   { }
 153
 154   ~Scan_relocs();
 155
 156   // The standard Task methods.
 157
 158   Task_token*
 159   is_runnable();
 160
 161   void
 162   locks(Task_locker*);
 163
 164   void
 165   run(Workqueue*);
 166
 167   std::string
 168   get_name() const;
 169
 170  private:
 171   Symbol_table* symtab_;
 172   Layout* layout_;
 173   Relobj* object_;
 174   Read_relocs_data* rd_;
 175   Task_token* this_blocker_;
 176   Task_token* next_blocker_;
 177 };
 178
 179 // A class to perform all the relocations for an object file.
 180
 181 class Relocate_task : public Task
 182 {
 183  public:
 184   Relocate_task(const Symbol_table* symtab, const Layout* layout,
 185                 Relobj* object, Output_file* of,
 186                 Task_token* input_sections_blocker,
 187                 Task_token* output_sections_blocker, Task_token* final_blocker)
 188     : symtab_(symtab), layout_(layout), object_(object), of_(of),
 189       input_sections_blocker_(input_sections_blocker),
 190       output_sections_blocker_(output_sections_blocker),
 191       final_blocker_(final_blocker)
 192   { }
 193
 194   // The standard Task methods.
 195
 196   Task_token*
 197   is_runnable();
 198
 199   void
 200   locks(Task_locker*);
 201
 202   void
 203   run(Workqueue*);
 204
 205   std::string
 206   get_name() const;
 207
 208  private:
 209   const Symbol_table* symtab_;
 210   const Layout* layout_;
 211   Relobj* object_;
 212   Output_file* of_;
 213   Task_token* input_sections_blocker_;
 214   Task_token* output_sections_blocker_;
 215   Task_token* final_blocker_;
 216 };
 217
 218 // During a relocatable link, this class records how relocations
 219 // should be handled for a single input reloc section.  An instance of
 220 // this class is created while scanning relocs, and it is used while
 221 // processing relocs.
 222
 223 class Relocatable_relocs
 224 {
 225  public:
 226   // We use a vector of unsigned char to indicate how the input relocs
 227   // should be handled.  Each element is one of the following values.
 228   // We create this vector when we initially scan the relocations.
 229   enum Reloc_strategy
 230   {
 231     // Copy the input reloc.  Don't modify it other than updating the
 232     // r_offset field and the r_sym part of the r_info field.
 233     RELOC_COPY,
 234     // Copy the input reloc which is against an STT_SECTION symbol.
 235     // Update the r_offset and r_sym part of the r_info field.  Adjust
 236     // the addend by subtracting the value of the old local symbol and
 237     // adding the value of the new local symbol.  The addend is in the
 238     // SHT_RELA reloc and the contents of the data section do not need
 239     // to be changed.
 240     RELOC_ADJUST_FOR_SECTION_RELA,
 241     // Like RELOC_ADJUST_FOR_SECTION_RELA but the addend should not be
 242     // adjusted.
 243     RELOC_ADJUST_FOR_SECTION_0,
 244     // Like RELOC_ADJUST_FOR_SECTION_RELA but the contents of the
 245     // section need to be changed.  The number indicates the number of
 246     // bytes in the addend in the section contents.
 247     RELOC_ADJUST_FOR_SECTION_1,
 248     RELOC_ADJUST_FOR_SECTION_2,
 249     RELOC_ADJUST_FOR_SECTION_4,
 250     RELOC_ADJUST_FOR_SECTION_8,
 251     // Like RELOC_ADJUST_FOR_SECTION_4 but for unaligned relocs.
 252     RELOC_ADJUST_FOR_SECTION_4_UNALIGNED,
 253     // Discard the input reloc--process it completely when relocating
 254     // the data section contents.
 255     RELOC_DISCARD,
 256     // An input reloc which is not discarded, but which requires
 257     // target specific processing in order to update it.
 258     RELOC_SPECIAL
 259   };
 260
 261   Relocatable_relocs()
 262     : reloc_strategies_(), output_reloc_count_(0), posd_(NULL)
 263   { }
 264
 265   // Record the number of relocs.
 266   void
 267   set_reloc_count(size_t reloc_count)
 268   { this->reloc_strategies_.reserve(reloc_count); }
 269
 270   // Record what to do for the next reloc.
 271   void
 272   set_next_reloc_strategy(Reloc_strategy strategy)
 273   {
 274     this->reloc_strategies_.push_back(static_cast<unsigned char>(strategy));
 275     if (strategy != RELOC_DISCARD)
 276       ++this->output_reloc_count_;
 277   }
 278
 279   // Record the Output_data associated with this reloc section.
 280   void
 281   set_output_data(Output_data* posd)
 282   {
 283     gold_assert(this->posd_ == NULL);
 284     this->posd_ = posd;
 285   }
 286
 287   // Return the Output_data associated with this reloc section.
 288   Output_data*
 289   output_data() const
 290   { return this->posd_; }
 291
 292   // Return what to do for reloc I.
 293   Reloc_strategy
 294   strategy(unsigned int i) const
 295   {
 296     gold_assert(i < this->reloc_strategies_.size());
 297     return static_cast<Reloc_strategy>(this->reloc_strategies_[i]);
 298   }
 299
 300   // Return the number of relocations to create in the output file.
 301   size_t
 302   output_reloc_count() const
 303   { return this->output_reloc_count_; }
 304
 305  private:
 306   typedef std::vector<unsigned char> Reloc_strategies;
 307
 308   // The strategies for the input reloc.  There is one entry in this
 309   // vector for each relocation in the input section.
 310   Reloc_strategies reloc_strategies_;
 311   // The number of relocations to be created in the output file.
 312   size_t output_reloc_count_;
 313   // The output data structure associated with this relocation.
 314   Output_data* posd_;
 315 };
 316
 317 // Standard relocation routines which are used on many targets.  Here
 318 // SIZE and BIG_ENDIAN refer to the target, not the relocation type.
 319
 320 template<int size, bool big_endian>
 321 class Relocate_functions
 322 {
 323 private:
 324   // Do a simple relocation with the addend in the section contents.
 325   // VALSIZE is the size of the value.
 326   template<int valsize>
 327   static inline void
 328   rel(unsigned char* view,
 329       typename elfcpp::Swap<valsize, big_endian>::Valtype value)
 330   {
 331     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 332     Valtype* wv = reinterpret_cast<Valtype*>(view);
 333     Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
 334     elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value);
 335   }
 336
 337   // Like the above but for relocs at unaligned addresses.
 338   template<int valsize>
 339   static inline void
 340   rel_unaligned(unsigned char* view,
 341                 typename elfcpp::Swap<valsize, big_endian>::Valtype value)
 342   {
 343     typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype
 344         Valtype;
 345     Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view);
 346     elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x + value);
 347   }
 348
 349   // Do a simple relocation using a Symbol_value with the addend in
 350   // the section contents.  VALSIZE is the size of the value to
 351   // relocate.
 352   template<int valsize>
 353   static inline void
 354   rel(unsigned char* view,
 355       const Sized_relobj_file<size, big_endian>* object,
 356       const Symbol_value<size>* psymval)
 357   {
 358     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 359     Valtype* wv = reinterpret_cast<Valtype*>(view);
 360     Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
 361     x = psymval->value(object, x);
 362     elfcpp::Swap<valsize, big_endian>::writeval(wv, x);
 363   }
 364
 365   // Like the above but for relocs at unaligned addresses.
 366   template<int valsize>
 367   static inline void
 368   rel_unaligned(unsigned char* view,
 369                 const Sized_relobj_file<size, big_endian>* object,
 370                 const Symbol_value<size>* psymval)
 371   {
 372     typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype
 373         Valtype;
 374     Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view);
 375     x = psymval->value(object, x);
 376     elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x);
 377   }
 378
 379   // Do a simple relocation with the addend in the relocation.
 380   // VALSIZE is the size of the value.
 381   template<int valsize>
 382   static inline void
 383   rela(unsigned char* view,
 384        typename elfcpp::Swap<valsize, big_endian>::Valtype value,
 385        typename elfcpp::Swap<valsize, big_endian>::Valtype addend)
 386   {
 387     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 388     Valtype* wv = reinterpret_cast<Valtype*>(view);
 389     elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend);
 390   }
 391
 392   // Do a simple relocation using a symbol value with the addend in
 393   // the relocation.  VALSIZE is the size of the value.
 394   template<int valsize>
 395   static inline void
 396   rela(unsigned char* view,
 397        const Sized_relobj_file<size, big_endian>* object,
 398        const Symbol_value<size>* psymval,
 399        typename elfcpp::Swap<valsize, big_endian>::Valtype addend)
 400   {
 401     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 402     Valtype* wv = reinterpret_cast<Valtype*>(view);
 403     Valtype x = psymval->value(object, addend);
 404     elfcpp::Swap<valsize, big_endian>::writeval(wv, x);
 405   }
 406
 407   // Do a simple PC relative relocation with the addend in the section
 408   // contents.  VALSIZE is the size of the value.
 409   template<int valsize>
 410   static inline void
 411   pcrel(unsigned char* view,
 412         typename elfcpp::Swap<valsize, big_endian>::Valtype value,
 413         typename elfcpp::Elf_types<size>::Elf_Addr address)
 414   {
 415     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 416     Valtype* wv = reinterpret_cast<Valtype*>(view);
 417     Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
 418     elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value - address);
 419   }
 420
 421   // Like the above but for relocs at unaligned addresses.
 422   template<int valsize>
 423   static inline void
 424   pcrel_unaligned(unsigned char* view,
 425                   typename elfcpp::Swap<valsize, big_endian>::Valtype value,
 426                   typename elfcpp::Elf_types<size>::Elf_Addr address)
 427   {
 428     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 429     Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view);
 430     elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view,
 431                                                           x + value - address);
 432   }
 433
 434   // Do a simple PC relative relocation with a Symbol_value with the
 435   // addend in the section contents.  VALSIZE is the size of the
 436   // value.
 437   template<int valsize>
 438   static inline void
 439   pcrel(unsigned char* view,
 440         const Sized_relobj_file<size, big_endian>* object,
 441         const Symbol_value<size>* psymval,
 442         typename elfcpp::Elf_types<size>::Elf_Addr address)
 443   {
 444     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 445     Valtype* wv = reinterpret_cast<Valtype*>(view);
 446     Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
 447     x = psymval->value(object, x);
 448     elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address);
 449   }
 450
 451   // Do a simple PC relative relocation with the addend in the
 452   // relocation.  VALSIZE is the size of the value.
 453   template<int valsize>
 454   static inline void
 455   pcrela(unsigned char* view,
 456          typename elfcpp::Swap<valsize, big_endian>::Valtype value,
 457          typename elfcpp::Swap<valsize, big_endian>::Valtype addend,
 458          typename elfcpp::Elf_types<size>::Elf_Addr address)
 459   {
 460     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 461     Valtype* wv = reinterpret_cast<Valtype*>(view);
 462     elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend - address);
 463   }
 464
 465   // Do a simple PC relative relocation with a Symbol_value with the
 466   // addend in the relocation.  VALSIZE is the size of the value.
 467   template<int valsize>
 468   static inline void
 469   pcrela(unsigned char* view,
 470          const Sized_relobj_file<size, big_endian>* object,
 471          const Symbol_value<size>* psymval,
 472          typename elfcpp::Swap<valsize, big_endian>::Valtype addend,
 473          typename elfcpp::Elf_types<size>::Elf_Addr address)
 474   {
 475     typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
 476     Valtype* wv = reinterpret_cast<Valtype*>(view);
 477     Valtype x = psymval->value(object, addend);
 478     elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address);
 479   }
 480
 481   typedef Relocate_functions<size, big_endian> This;
 482
 483 public:
 484   // Do a simple 8-bit REL relocation with the addend in the section
 485   // contents.
 486   static inline void
 487   rel8(unsigned char* view, unsigned char value)
 488   { This::template rel<8>(view, value); }
 489
 490   static inline void
 491   rel8(unsigned char* view,
 492        const Sized_relobj_file<size, big_endian>* object,
 493        const Symbol_value<size>* psymval)
 494   { This::template rel<8>(view, object, psymval); }
 495
 496   // Do an 8-bit RELA relocation with the addend in the relocation.
 497   static inline void
 498   rela8(unsigned char* view, unsigned char value, unsigned char addend)
 499   { This::template rela<8>(view, value, addend); }
 500
 501   static inline void
 502   rela8(unsigned char* view,
 503         const Sized_relobj_file<size, big_endian>* object,
 504         const Symbol_value<size>* psymval,
 505         unsigned char addend)
 506   { This::template rela<8>(view, object, psymval, addend); }
 507
 508   // Do a simple 8-bit PC relative relocation with the addend in the
 509   // section contents.
 510   static inline void
 511   pcrel8(unsigned char* view, unsigned char value,
 512          typename elfcpp::Elf_types<size>::Elf_Addr address)
 513   { This::template pcrel<8>(view, value, address); }
 514
 515   static inline void
 516   pcrel8(unsigned char* view,
 517          const Sized_relobj_file<size, big_endian>* object,
 518          const Symbol_value<size>* psymval,
 519          typename elfcpp::Elf_types<size>::Elf_Addr address)
 520   { This::template pcrel<8>(view, object, psymval, address); }
 521
 522   // Do a simple 8-bit PC relative RELA relocation with the addend in
 523   // the reloc.
 524   static inline void
 525   pcrela8(unsigned char* view, unsigned char value, unsigned char addend,
 526           typename elfcpp::Elf_types<size>::Elf_Addr address)
 527   { This::template pcrela<8>(view, value, addend, address); }
 528
 529   static inline void
 530   pcrela8(unsigned char* view,
 531           const Sized_relobj_file<size, big_endian>* object,
 532           const Symbol_value<size>* psymval,
 533           unsigned char addend,
 534           typename elfcpp::Elf_types<size>::Elf_Addr address)
 535   { This::template pcrela<8>(view, object, psymval, addend, address); }
 536
 537   // Do a simple 16-bit REL relocation with the addend in the section
 538   // contents.
 539   static inline void
 540   rel16(unsigned char* view, elfcpp::Elf_Half value)
 541   { This::template rel<16>(view, value); }
 542
 543   static inline void
 544   rel16(unsigned char* view,
 545         const Sized_relobj_file<size, big_endian>* object,
 546         const Symbol_value<size>* psymval)
 547   { This::template rel<16>(view, object, psymval); }
 548
 549   // Do an 16-bit RELA relocation with the addend in the relocation.
 550   static inline void
 551   rela16(unsigned char* view, elfcpp::Elf_Half value, elfcpp::Elf_Half addend)
 552   { This::template rela<16>(view, value, addend); }
 553
 554   static inline void
 555   rela16(unsigned char* view,
 556          const Sized_relobj_file<size, big_endian>* object,
 557          const Symbol_value<size>* psymval,
 558          elfcpp::Elf_Half addend)
 559   { This::template rela<16>(view, object, psymval, addend); }
 560
 561   // Do a simple 16-bit PC relative REL relocation with the addend in
 562   // the section contents.
 563   static inline void
 564   pcrel16(unsigned char* view, elfcpp::Elf_Half value,
 565           typename elfcpp::Elf_types<size>::Elf_Addr address)
 566   { This::template pcrel<16>(view, value, address); }
 567
 568   static inline void
 569   pcrel16(unsigned char* view,
 570           const Sized_relobj_file<size, big_endian>* object,
 571           const Symbol_value<size>* psymval,
 572           typename elfcpp::Elf_types<size>::Elf_Addr address)
 573   { This::template pcrel<16>(view, object, psymval, address); }
 574
 575   // Do a simple 16-bit PC relative RELA relocation with the addend in
 576   // the reloc.
 577   static inline void
 578   pcrela16(unsigned char* view, elfcpp::Elf_Half value,
 579            elfcpp::Elf_Half addend,
 580            typename elfcpp::Elf_types<size>::Elf_Addr address)
 581   { This::template pcrela<16>(view, value, addend, address); }
 582
 583   static inline void
 584   pcrela16(unsigned char* view,
 585            const Sized_relobj_file<size, big_endian>* object,
 586            const Symbol_value<size>* psymval,
 587            elfcpp::Elf_Half addend,
 588            typename elfcpp::Elf_types<size>::Elf_Addr address)
 589   { This::template pcrela<16>(view, object, psymval, addend, address); }
 590
 591   // Do a simple 32-bit REL relocation with the addend in the section
 592   // contents.
 593   static inline void
 594   rel32(unsigned char* view, elfcpp::Elf_Word value)
 595   { This::template rel<32>(view, value); }
 596
 597   // Like above but for relocs at unaligned addresses.
 598   static inline void
 599   rel32_unaligned(unsigned char* view, elfcpp::Elf_Word value)
 600   { This::template rel_unaligned<32>(view, value); }
 601
 602   static inline void
 603   rel32(unsigned char* view,
 604         const Sized_relobj_file<size, big_endian>* object,
 605         const Symbol_value<size>* psymval)
 606   { This::template rel<32>(view, object, psymval); }
 607
 608   // Like above but for relocs at unaligned addresses.
 609   static inline void
 610   rel32_unaligned(unsigned char* view,
 611                   const Sized_relobj_file<size, big_endian>* object,
 612                   const Symbol_value<size>* psymval)
 613   { This::template rel_unaligned<32>(view, object, psymval); }
 614
 615   // Do an 32-bit RELA relocation with the addend in the relocation.
 616   static inline void
 617   rela32(unsigned char* view, elfcpp::Elf_Word value, elfcpp::Elf_Word addend)
 618   { This::template rela<32>(view, value, addend); }
 619
 620   static inline void
 621   rela32(unsigned char* view,
 622          const Sized_relobj_file<size, big_endian>* object,
 623          const Symbol_value<size>* psymval,
 624          elfcpp::Elf_Word addend)
 625   { This::template rela<32>(view, object, psymval, addend); }
 626
 627   // Do a simple 32-bit PC relative REL relocation with the addend in
 628   // the section contents.
 629   static inline void
 630   pcrel32(unsigned char* view, elfcpp::Elf_Word value,
 631           typename elfcpp::Elf_types<size>::Elf_Addr address)
 632   { This::template pcrel<32>(view, value, address); }
 633
 634   // Unaligned version of the above.
 635   static inline void
 636   pcrel32_unaligned(unsigned char* view, elfcpp::Elf_Word value,
 637                     typename elfcpp::Elf_types<size>::Elf_Addr address)
 638   { This::template pcrel_unaligned<32>(view, value, address); }
 639
 640   static inline void
 641   pcrel32(unsigned char* view,
 642           const Sized_relobj_file<size, big_endian>* object,
 643           const Symbol_value<size>* psymval,
 644           typename elfcpp::Elf_types<size>::Elf_Addr address)
 645   { This::template pcrel<32>(view, object, psymval, address); }
 646
 647   // Do a simple 32-bit PC relative RELA relocation with the addend in
 648   // the relocation.
 649   static inline void
 650   pcrela32(unsigned char* view, elfcpp::Elf_Word value,
 651            elfcpp::Elf_Word addend,
 652            typename elfcpp::Elf_types<size>::Elf_Addr address)
 653   { This::template pcrela<32>(view, value, addend, address); }
 654
 655   static inline void
 656   pcrela32(unsigned char* view,
 657            const Sized_relobj_file<size, big_endian>* object,
 658            const Symbol_value<size>* psymval,
 659            elfcpp::Elf_Word addend,
 660            typename elfcpp::Elf_types<size>::Elf_Addr address)
 661   { This::template pcrela<32>(view, object, psymval, addend, address); }
 662
 663   // Do a simple 64-bit REL relocation with the addend in the section
 664   // contents.
 665   static inline void
 666   rel64(unsigned char* view, elfcpp::Elf_Xword value)
 667   { This::template rel<64>(view, value); }
 668
 669   static inline void
 670   rel64(unsigned char* view,
 671         const Sized_relobj_file<size, big_endian>* object,
 672         const Symbol_value<size>* psymval)
 673   { This::template rel<64>(view, object, psymval); }
 674
 675   // Do a 64-bit RELA relocation with the addend in the relocation.
 676   static inline void
 677   rela64(unsigned char* view, elfcpp::Elf_Xword value,
 678          elfcpp::Elf_Xword addend)
 679   { This::template rela<64>(view, value, addend); }
 680
 681   static inline void
 682   rela64(unsigned char* view,
 683          const Sized_relobj_file<size, big_endian>* object,
 684          const Symbol_value<size>* psymval,
 685          elfcpp::Elf_Xword addend)
 686   { This::template rela<64>(view, object, psymval, addend); }
 687
 688   // Do a simple 64-bit PC relative REL relocation with the addend in
 689   // the section contents.
 690   static inline void
 691   pcrel64(unsigned char* view, elfcpp::Elf_Xword value,
 692           typename elfcpp::Elf_types<size>::Elf_Addr address)
 693   { This::template pcrel<64>(view, value, address); }
 694
 695   static inline void
 696   pcrel64(unsigned char* view,
 697           const Sized_relobj_file<size, big_endian>* object,
 698           const Symbol_value<size>* psymval,
 699           typename elfcpp::Elf_types<size>::Elf_Addr address)
 700   { This::template pcrel<64>(view, object, psymval, address); }
 701
 702   // Do a simple 64-bit PC relative RELA relocation with the addend in
 703   // the relocation.
 704   static inline void
 705   pcrela64(unsigned char* view, elfcpp::Elf_Xword value,
 706            elfcpp::Elf_Xword addend,
 707            typename elfcpp::Elf_types<size>::Elf_Addr address)
 708   { This::template pcrela<64>(view, value, addend, address); }
 709
 710   static inline void
 711   pcrela64(unsigned char* view,
 712            const Sized_relobj_file<size, big_endian>* object,
 713            const Symbol_value<size>* psymval,
 714            elfcpp::Elf_Xword addend,
 715            typename elfcpp::Elf_types<size>::Elf_Addr address)
 716   { This::template pcrela<64>(view, object, psymval, addend, address); }
 717 };
 718
 719 // Integer manipulation functions used by various targets when
 720 // performing relocations.
 721
 722 template<int bits>
 723 class Bits
 724 {
 725  public:
 726   // Sign extend an n-bit unsigned integer stored in a uint32_t into
 727   // an int32_t.  BITS must be between 1 and 32.
 728   static inline int32_t
 729   sign_extend32(uint32_t val)
 730   {
 731     gold_assert(bits > 0 && bits <= 32);
 732     if (bits == 32)
 733       return static_cast<int32_t>(val);
 734     uint32_t mask = (~static_cast<uint32_t>(0)) >> (32 - bits);
 735     val &= mask;
 736     uint32_t top_bit = 1U << (bits - 1);
 737     int32_t as_signed = static_cast<int32_t>(val);
 738     if ((val & top_bit) != 0)
 739       as_signed -= static_cast<int32_t>(top_bit * 2);
 740     return as_signed;
 741   }
 742
 743   // Return true if VAL (stored in a uint32_t) has overflowed a signed
 744   // value with BITS bits.
 745   static inline bool
 746   has_overflow32(uint32_t val)
 747   {
 748     gold_assert(bits > 0 && bits <= 32);
 749     if (bits == 32)
 750       return false;
 751     int32_t max = (1 << (bits - 1)) - 1;
 752     int32_t min = -(1 << (bits - 1));
 753     int32_t as_signed = static_cast<int32_t>(val);
 754     return as_signed > max || as_signed < min;
 755   }
 756
 757   // Return true if VAL (stored in a uint32_t) has overflowed both a
 758   // signed and an unsigned value.  E.g.,
 759   // Bits<8>::has_signed_unsigned_overflow32 would check -128 <= VAL <
 760   // 255.
 761   static inline bool
 762   has_signed_unsigned_overflow32(uint32_t val)
 763   {
 764     gold_assert(bits > 0 && bits <= 32);
 765     if (bits == 32)
 766       return false;
 767     int32_t max = static_cast<int32_t>((1U << bits) - 1);
 768     int32_t min = -(1 << (bits - 1));
 769     int32_t as_signed = static_cast<int32_t>(val);
 770     return as_signed > max || as_signed < min;
 771   }
 772
 773   // Select bits from A and B using bits in MASK.  For each n in
 774   // [0..31], the n-th bit in the result is chosen from the n-th bits
 775   // of A and B.  A zero selects A and a one selects B.
 776   static inline uint32_t
 777   bit_select32(uint32_t a, uint32_t b, uint32_t mask)
 778   { return (a & ~mask) | (b & mask); }
 779
 780   // Sign extend an n-bit unsigned integer stored in a uint64_t into
 781   // an int64_t.  BITS must be between 1 and 64.
 782   static inline int64_t
 783   sign_extend(uint64_t val)
 784   {
 785     gold_assert(bits > 0 && bits <= 64);
 786     if (bits == 64)
 787       return static_cast<int64_t>(val);
 788     uint64_t mask = (~static_cast<uint64_t>(0)) >> (64 - bits);
 789     val &= mask;
 790     uint64_t top_bit = static_cast<uint64_t>(1) << (bits - 1);
 791     int64_t as_signed = static_cast<int64_t>(val);
 792     if ((val & top_bit) != 0)
 793       as_signed -= static_cast<int64_t>(top_bit * 2);
 794     return as_signed;
 795   }
 796
 797   // Return true if VAL (stored in a uint64_t) has overflowed a signed
 798   // value with BITS bits.
 799   static inline bool
 800   has_overflow(uint64_t val)
 801   {
 802     gold_assert(bits > 0 && bits <= 64);
 803     if (bits == 64)
 804       return false;
 805     int64_t max = (static_cast<int64_t>(1) << (bits - 1)) - 1;
 806     int64_t min = -(static_cast<int64_t>(1) << (bits - 1));
 807     int64_t as_signed = static_cast<int64_t>(val);
 808     return as_signed > max || as_signed < min;
 809   }
 810
 811   // Return true if VAL (stored in a uint64_t) has overflowed both a
 812   // signed and an unsigned value.  E.g.,
 813   // Bits<8>::has_signed_unsigned_overflow would check -128 <= VAL <
 814   // 255.
 815   static inline bool
 816   has_signed_unsigned_overflow64(uint64_t val)
 817   {
 818     gold_assert(bits > 0 && bits <= 64);
 819     if (bits == 64)
 820       return false;
 821     int64_t max = static_cast<int64_t>((static_cast<uint64_t>(1) << bits) - 1);
 822     int64_t min = -(static_cast<int64_t>(1) << (bits - 1));
 823     int64_t as_signed = static_cast<int64_t>(val);
 824     return as_signed > max || as_signed < min;
 825   }
 826
 827   // Select bits from A and B using bits in MASK.  For each n in
 828   // [0..31], the n-th bit in the result is chosen from the n-th bits
 829   // of A and B.  A zero selects A and a one selects B.
 830   static inline uint64_t
 831   bit_select64(uint64_t a, uint64_t b, uint64_t mask)
 832   { return (a & ~mask) | (b & mask); }
 833 };
 834
 835 // Track relocations while reading a section.  This lets you ask for
 836 // the relocation at a certain offset, and see how relocs occur
 837 // between points of interest.
 838
 839 template<int size, bool big_endian>
 840 class Track_relocs
 841 {
 842  public:
 843   Track_relocs()
 844     : prelocs_(NULL), len_(0), pos_(0), reloc_size_(0)
 845   { }
 846
 847   // Initialize the Track_relocs object.  OBJECT is the object holding
 848   // the reloc section, RELOC_SHNDX is the section index of the reloc
 849   // section, and RELOC_TYPE is the type of the reloc section
 850   // (elfcpp::SHT_REL or elfcpp::SHT_RELA).  This returns false if
 851   // something went wrong.
 852   bool
 853   initialize(Object* object, unsigned int reloc_shndx,
 854              unsigned int reloc_type);
 855
 856   // Return the offset in the data section to which the next reloc
 857   // applies.  This returns -1 if there is no next reloc.
 858   off_t
 859   next_offset() const;
 860
 861   // Return the symbol index of the next reloc.  This returns -1U if
 862   // there is no next reloc.
 863   unsigned int
 864   next_symndx() const;
 865
 866   // Return the addend of the next reloc.  This returns 0 if there is
 867   // no next reloc.
 868   uint64_t
 869   next_addend() const;
 870
 871   // Advance to OFFSET within the data section, and return the number
 872   // of relocs which would be skipped.
 873   int
 874   advance(off_t offset);
 875
 876   // Checkpoint the current position in the reloc section.
 877   section_size_type
 878   checkpoint() const
 879   { return this->pos_; }
 880
 881   // Reset the position to CHECKPOINT.
 882   void
 883   reset(section_size_type checkpoint)
 884   { this->pos_ = checkpoint; }
 885
 886  private:
 887   // The contents of the input object's reloc section.
 888   const unsigned char* prelocs_;
 889   // The length of the reloc section.
 890   section_size_type len_;
 891   // Our current position in the reloc section.
 892   section_size_type pos_;
 893   // The size of the relocs in the section.
 894   int reloc_size_;
 895 };
 896
 897 } // End namespace gold.
 898
 899 #endif // !defined(GOLD_RELOC_H)