gold/script-sections.cc

   1 // script-sections.cc -- linker script SECTIONS for gold
   2
   3 // Copyright 2008, 2009, 2010, 2011 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 <cstring>
  26 #include <algorithm>
  27 #include <list>
  28 #include <map>
  29 #include <string>
  30 #include <vector>
  31 #include <fnmatch.h>
  32
  33 #include "parameters.h"
  34 #include "object.h"
  35 #include "layout.h"
  36 #include "output.h"
  37 #include "script-c.h"
  38 #include "script.h"
  39 #include "script-sections.h"
  40
  41 // Support for the SECTIONS clause in linker scripts.
  42
  43 namespace gold
  44 {
  45
  46 // A region of memory.
  47 class Memory_region
  48 {
  49  public:
  50   Memory_region(const char* name, size_t namelen, unsigned int attributes,
  51                 Expression* start, Expression* length)
  52     : name_(name, namelen),
  53       attributes_(attributes),
  54       start_(start),
  55       length_(length),
  56       current_offset_(0),
  57       vma_sections_(),
  58       lma_sections_(),
  59       last_section_(NULL)
  60   { }
  61
  62   // Return the name of this region.
  63   const std::string&
  64   name() const
  65   { return this->name_; }
  66
  67   // Return the start address of this region.
  68   Expression*
  69   start_address() const
  70   { return this->start_; }
  71
  72   // Return the length of this region.
  73   Expression*
  74   length() const
  75   { return this->length_; }
  76
  77   // Print the region (when debugging).
  78   void
  79   print(FILE*) const;
  80
  81   // Return true if <name,namelen> matches this region.
  82   bool
  83   name_match(const char* name, size_t namelen)
  84   {
  85     return (this->name_.length() == namelen
  86             && strncmp(this->name_.c_str(), name, namelen) == 0);
  87   }
  88
  89   Expression*
  90   get_current_address() const
  91   {
  92     return
  93       script_exp_binary_add(this->start_,
  94                             script_exp_integer(this->current_offset_));
  95   }
  96
  97   void
  98   increment_offset(std::string section_name, uint64_t amount,
  99                    const Symbol_table* symtab, const Layout* layout)
 100   {
 101     this->current_offset_ += amount;
 102
 103     if (this->current_offset_
 104         > this->length_->eval(symtab, layout, false))
 105       gold_error(_("section %s overflows end of region %s"),
 106                  section_name.c_str(), this->name_.c_str());
 107   }
 108
 109   // Returns true iff there is room left in this region
 110   // for AMOUNT more bytes of data.
 111   bool
 112   has_room_for(const Symbol_table* symtab, const Layout* layout,
 113                uint64_t amount) const
 114   {
 115     return (this->current_offset_ + amount
 116             < this->length_->eval(symtab, layout, false));
 117   }
 118
 119   // Return true if the provided section flags
 120   // are compatible with this region's attributes.
 121   bool
 122   attributes_compatible(elfcpp::Elf_Xword flags, elfcpp::Elf_Xword type) const;
 123
 124   void
 125   add_section(Output_section_definition* sec, bool vma)
 126   {
 127     if (vma)
 128       this->vma_sections_.push_back(sec);
 129     else
 130       this->lma_sections_.push_back(sec);
 131   }
 132
 133   typedef std::vector<Output_section_definition*> Section_list;
 134
 135   // Return the start of the list of sections
 136   // whose VMAs are taken from this region.
 137   Section_list::const_iterator
 138   get_vma_section_list_start() const
 139   { return this->vma_sections_.begin(); }
 140
 141   // Return the start of the list of sections
 142   // whose LMAs are taken from this region.
 143   Section_list::const_iterator
 144   get_lma_section_list_start() const
 145   { return this->lma_sections_.begin(); }
 146
 147   // Return the end of the list of sections
 148   // whose VMAs are taken from this region.
 149   Section_list::const_iterator
 150   get_vma_section_list_end() const
 151   { return this->vma_sections_.end(); }
 152
 153   // Return the end of the list of sections
 154   // whose LMAs are taken from this region.
 155   Section_list::const_iterator
 156   get_lma_section_list_end() const
 157   { return this->lma_sections_.end(); }
 158
 159   Output_section_definition*
 160   get_last_section() const
 161   { return this->last_section_; }
 162
 163   void
 164   set_last_section(Output_section_definition* sec)
 165   { this->last_section_ = sec; }
 166
 167  private:
 168
 169   std::string name_;
 170   unsigned int attributes_;
 171   Expression* start_;
 172   Expression* length_;
 173   // The offset to the next free byte in the region.
 174   // Note - for compatibility with GNU LD we only maintain one offset
 175   // regardless of whether the region is being used for VMA values,
 176   // LMA values, or both.
 177   uint64_t current_offset_;
 178   // A list of sections whose VMAs are set inside this region.
 179   Section_list vma_sections_;
 180   // A list of sections whose LMAs are set inside this region.
 181   Section_list lma_sections_;
 182   // The latest section to make use of this region.
 183   Output_section_definition* last_section_;
 184 };
 185
 186 // Return true if the provided section flags
 187 // are compatible with this region's attributes.
 188
 189 bool
 190 Memory_region::attributes_compatible(elfcpp::Elf_Xword flags,
 191                                      elfcpp::Elf_Xword type) const
 192 {
 193   unsigned int attrs = this->attributes_;
 194
 195   // No attributes means that this region is not compatible with anything.
 196   if (attrs == 0)
 197     return false;
 198
 199   bool match = true;
 200   do
 201     {
 202       switch (attrs & - attrs)
 203         {
 204         case MEM_EXECUTABLE:
 205           if ((flags & elfcpp::SHF_EXECINSTR) == 0)
 206             match = false;
 207           break;
 208
 209         case MEM_WRITEABLE:
 210           if ((flags & elfcpp::SHF_WRITE) == 0)
 211             match = false;
 212           break;
 213
 214         case MEM_READABLE:
 215           // All sections are presumed readable.
 216           break;
 217
 218         case MEM_ALLOCATABLE:
 219           if ((flags & elfcpp::SHF_ALLOC) == 0)
 220             match = false;
 221           break;
 222
 223         case MEM_INITIALIZED:
 224           if ((type & elfcpp::SHT_NOBITS) != 0)
 225             match = false;
 226           break;
 227         }
 228       attrs &= ~ (attrs & - attrs);
 229     }
 230   while (attrs != 0);
 231
 232   return match;
 233 }
 234
 235 // Print a memory region.
 236
 237 void
 238 Memory_region::print(FILE* f) const
 239 {
 240   fprintf(f, "  %s", this->name_.c_str());
 241
 242   unsigned int attrs = this->attributes_;
 243   if (attrs != 0)
 244     {
 245       fprintf(f, " (");
 246       do
 247         {
 248           switch (attrs & - attrs)
 249             {
 250             case MEM_EXECUTABLE:  fputc('x', f); break;
 251             case MEM_WRITEABLE:   fputc('w', f); break;
 252             case MEM_READABLE:    fputc('r', f); break;
 253             case MEM_ALLOCATABLE: fputc('a', f); break;
 254             case MEM_INITIALIZED: fputc('i', f); break;
 255             default:
 256               gold_unreachable();
 257             }
 258           attrs &= ~ (attrs & - attrs);
 259         }
 260       while (attrs != 0);
 261       fputc(')', f);
 262     }
 263
 264   fprintf(f, " : origin = ");
 265   this->start_->print(f);
 266   fprintf(f, ", length = ");
 267   this->length_->print(f);
 268   fprintf(f, "\n");
 269 }
 270
 271 // Manage orphan sections.  This is intended to be largely compatible
 272 // with the GNU linker.  The Linux kernel implicitly relies on
 273 // something similar to the GNU linker's orphan placement.  We
 274 // originally used a simpler scheme here, but it caused the kernel
 275 // build to fail, and was also rather inefficient.
 276
 277 class Orphan_section_placement
 278 {
 279  private:
 280   typedef Script_sections::Elements_iterator Elements_iterator;
 281
 282  public:
 283   Orphan_section_placement();
 284
 285   // Handle an output section during initialization of this mapping.
 286   void
 287   output_section_init(const std::string& name, Output_section*,
 288                       Elements_iterator location);
 289
 290   // Initialize the last location.
 291   void
 292   last_init(Elements_iterator location);
 293
 294   // Set *PWHERE to the address of an iterator pointing to the
 295   // location to use for an orphan section.  Return true if the
 296   // iterator has a value, false otherwise.
 297   bool
 298   find_place(Output_section*, Elements_iterator** pwhere);
 299
 300   // Return the iterator being used for sections at the very end of
 301   // the linker script.
 302   Elements_iterator
 303   last_place() const;
 304
 305  private:
 306   // The places that we specifically recognize.  This list is copied
 307   // from the GNU linker.
 308   enum Place_index
 309   {
 310     PLACE_TEXT,
 311     PLACE_RODATA,
 312     PLACE_DATA,
 313     PLACE_TLS,
 314     PLACE_TLS_BSS,
 315     PLACE_BSS,
 316     PLACE_REL,
 317     PLACE_INTERP,
 318     PLACE_NONALLOC,
 319     PLACE_LAST,
 320     PLACE_MAX
 321   };
 322
 323   // The information we keep for a specific place.
 324   struct Place
 325   {
 326     // The name of sections for this place.
 327     const char* name;
 328     // Whether we have a location for this place.
 329     bool have_location;
 330     // The iterator for this place.
 331     Elements_iterator location;
 332   };
 333
 334   // Initialize one place element.
 335   void
 336   initialize_place(Place_index, const char*);
 337
 338   // The places.
 339   Place places_[PLACE_MAX];
 340   // True if this is the first call to output_section_init.
 341   bool first_init_;
 342 };
 343
 344 // Initialize Orphan_section_placement.
 345
 346 Orphan_section_placement::Orphan_section_placement()
 347   : first_init_(true)
 348 {
 349   this->initialize_place(PLACE_TEXT, ".text");
 350   this->initialize_place(PLACE_RODATA, ".rodata");
 351   this->initialize_place(PLACE_DATA, ".data");
 352   this->initialize_place(PLACE_TLS, NULL);
 353   this->initialize_place(PLACE_TLS_BSS, NULL);
 354   this->initialize_place(PLACE_BSS, ".bss");
 355   this->initialize_place(PLACE_REL, NULL);
 356   this->initialize_place(PLACE_INTERP, ".interp");
 357   this->initialize_place(PLACE_NONALLOC, NULL);
 358   this->initialize_place(PLACE_LAST, NULL);
 359 }
 360
 361 // Initialize one place element.
 362
 363 void
 364 Orphan_section_placement::initialize_place(Place_index index, const char* name)
 365 {
 366   this->places_[index].name = name;
 367   this->places_[index].have_location = false;
 368 }
 369
 370 // While initializing the Orphan_section_placement information, this
 371 // is called once for each output section named in the linker script.
 372 // If we found an output section during the link, it will be passed in
 373 // OS.
 374
 375 void
 376 Orphan_section_placement::output_section_init(const std::string& name,
 377                                               Output_section* os,
 378                                               Elements_iterator location)
 379 {
 380   bool first_init = this->first_init_;
 381   this->first_init_ = false;
 382
 383   for (int i = 0; i < PLACE_MAX; ++i)
 384     {
 385       if (this->places_[i].name != NULL && this->places_[i].name == name)
 386         {
 387           if (this->places_[i].have_location)
 388             {
 389               // We have already seen a section with this name.
 390               return;
 391             }
 392
 393           this->places_[i].location = location;
 394           this->places_[i].have_location = true;
 395
 396           // If we just found the .bss section, restart the search for
 397           // an unallocated section.  This follows the GNU linker's
 398           // behaviour.
 399           if (i == PLACE_BSS)
 400             this->places_[PLACE_NONALLOC].have_location = false;
 401
 402           return;
 403         }
 404     }
 405
 406   // Relocation sections.
 407   if (!this->places_[PLACE_REL].have_location
 408       && os != NULL
 409       && (os->type() == elfcpp::SHT_REL || os->type() == elfcpp::SHT_RELA)
 410       && (os->flags() & elfcpp::SHF_ALLOC) != 0)
 411     {
 412       this->places_[PLACE_REL].location = location;
 413       this->places_[PLACE_REL].have_location = true;
 414     }
 415
 416   // We find the location for unallocated sections by finding the
 417   // first debugging or comment section after the BSS section (if
 418   // there is one).
 419   if (!this->places_[PLACE_NONALLOC].have_location
 420       && (name == ".comment" || Layout::is_debug_info_section(name.c_str())))
 421     {
 422       // We add orphan sections after the location in PLACES_.  We
 423       // want to store unallocated sections before LOCATION.  If this
 424       // is the very first section, we can't use it.
 425       if (!first_init)
 426         {
 427           --location;
 428           this->places_[PLACE_NONALLOC].location = location;
 429           this->places_[PLACE_NONALLOC].have_location = true;
 430         }
 431     }
 432 }
 433
 434 // Initialize the last location.
 435
 436 void
 437 Orphan_section_placement::last_init(Elements_iterator location)
 438 {
 439   this->places_[PLACE_LAST].location = location;
 440   this->places_[PLACE_LAST].have_location = true;
 441 }
 442
 443 // Set *PWHERE to the address of an iterator pointing to the location
 444 // to use for an orphan section.  Return true if the iterator has a
 445 // value, false otherwise.
 446
 447 bool
 448 Orphan_section_placement::find_place(Output_section* os,
 449                                      Elements_iterator** pwhere)
 450 {
 451   // Figure out where OS should go.  This is based on the GNU linker
 452   // code.  FIXME: The GNU linker handles small data sections
 453   // specially, but we don't.
 454   elfcpp::Elf_Word type = os->type();
 455   elfcpp::Elf_Xword flags = os->flags();
 456   Place_index index;
 457   if ((flags & elfcpp::SHF_ALLOC) == 0
 458       && !Layout::is_debug_info_section(os->name()))
 459     index = PLACE_NONALLOC;
 460   else if ((flags & elfcpp::SHF_ALLOC) == 0)
 461     index = PLACE_LAST;
 462   else if (type == elfcpp::SHT_NOTE)
 463     index = PLACE_INTERP;
 464   else if ((flags & elfcpp::SHF_TLS) != 0)
 465     {
 466       if (type == elfcpp::SHT_NOBITS)
 467         index = PLACE_TLS_BSS;
 468       else
 469         index = PLACE_TLS;
 470     }
 471   else if (type == elfcpp::SHT_NOBITS)
 472     index = PLACE_BSS;
 473   else if ((flags & elfcpp::SHF_WRITE) != 0)
 474     index = PLACE_DATA;
 475   else if (type == elfcpp::SHT_REL || type == elfcpp::SHT_RELA)
 476     index = PLACE_REL;
 477   else if ((flags & elfcpp::SHF_EXECINSTR) == 0)
 478     index = PLACE_RODATA;
 479   else
 480     index = PLACE_TEXT;
 481
 482   // If we don't have a location yet, try to find one based on a
 483   // plausible ordering of sections.
 484   if (!this->places_[index].have_location)
 485     {
 486       Place_index follow;
 487       switch (index)
 488         {
 489         default:
 490           follow = PLACE_MAX;
 491           break;
 492         case PLACE_RODATA:
 493           follow = PLACE_TEXT;
 494           break;
 495         case PLACE_BSS:
 496           follow = PLACE_DATA;
 497           break;
 498         case PLACE_REL:
 499           follow = PLACE_TEXT;
 500           break;
 501         case PLACE_INTERP:
 502           follow = PLACE_TEXT;
 503           break;
 504         case PLACE_TLS:
 505           follow = PLACE_DATA;
 506           break;
 507         case PLACE_TLS_BSS:
 508           follow = PLACE_TLS;
 509           if (!this->places_[PLACE_TLS].have_location)
 510             follow = PLACE_DATA;
 511           break;
 512         }
 513       if (follow != PLACE_MAX && this->places_[follow].have_location)
 514         {
 515           // Set the location of INDEX to the location of FOLLOW.  The
 516           // location of INDEX will then be incremented by the caller,
 517           // so anything in INDEX will continue to be after anything
 518           // in FOLLOW.
 519           this->places_[index].location = this->places_[follow].location;
 520           this->places_[index].have_location = true;
 521         }
 522     }
 523
 524   *pwhere = &this->places_[index].location;
 525   bool ret = this->places_[index].have_location;
 526
 527   // The caller will set the location.
 528   this->places_[index].have_location = true;
 529
 530   return ret;
 531 }
 532
 533 // Return the iterator being used for sections at the very end of the
 534 // linker script.
 535
 536 Orphan_section_placement::Elements_iterator
 537 Orphan_section_placement::last_place() const
 538 {
 539   gold_assert(this->places_[PLACE_LAST].have_location);
 540   return this->places_[PLACE_LAST].location;
 541 }
 542
 543 // An element in a SECTIONS clause.
 544
 545 class Sections_element
 546 {
 547  public:
 548   Sections_element()
 549   { }
 550
 551   virtual ~Sections_element()
 552   { }
 553
 554   // Return whether an output section is relro.
 555   virtual bool
 556   is_relro() const
 557   { return false; }
 558
 559   // Record that an output section is relro.
 560   virtual void
 561   set_is_relro()
 562   { }
 563
 564   // Create any required output sections.  The only real
 565   // implementation is in Output_section_definition.
 566   virtual void
 567   create_sections(Layout*)
 568   { }
 569
 570   // Add any symbol being defined to the symbol table.
 571   virtual void
 572   add_symbols_to_table(Symbol_table*)
 573   { }
 574
 575   // Finalize symbols and check assertions.
 576   virtual void
 577   finalize_symbols(Symbol_table*, const Layout*, uint64_t*)
 578   { }
 579
 580   // Return the output section name to use for an input file name and
 581   // section name.  This only real implementation is in
 582   // Output_section_definition.
 583   virtual const char*
 584   output_section_name(const char*, const char*, Output_section***,
 585                       Script_sections::Section_type*, bool*)
 586   { return NULL; }
 587
 588   // Initialize OSP with an output section.
 589   virtual void
 590   orphan_section_init(Orphan_section_placement*,
 591                       Script_sections::Elements_iterator)
 592   { }
 593
 594   // Set section addresses.  This includes applying assignments if the
 595   // expression is an absolute value.
 596   virtual void
 597   set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*,
 598                         uint64_t*)
 599   { }
 600
 601   // Check a constraint (ONLY_IF_RO, etc.) on an output section.  If
 602   // this section is constrained, and the input sections do not match,
 603   // return the constraint, and set *POSD.
 604   virtual Section_constraint
 605   check_constraint(Output_section_definition**)
 606   { return CONSTRAINT_NONE; }
 607
 608   // See if this is the alternate output section for a constrained
 609   // output section.  If it is, transfer the Output_section and return
 610   // true.  Otherwise return false.
 611   virtual bool
 612   alternate_constraint(Output_section_definition*, Section_constraint)
 613   { return false; }
 614
 615   // Get the list of segments to use for an allocated section when
 616   // using a PHDRS clause.  If this is an allocated section, return
 617   // the Output_section, and set *PHDRS_LIST (the first parameter) to
 618   // the list of PHDRS to which it should be attached.  If the PHDRS
 619   // were not specified, don't change *PHDRS_LIST.  When not returning
 620   // NULL, set *ORPHAN (the second parameter) according to whether
 621   // this is an orphan section--one that is not mentioned in the
 622   // linker script.
 623   virtual Output_section*
 624   allocate_to_segment(String_list**, bool*)
 625   { return NULL; }
 626
 627   // Look for an output section by name and return the address, the
 628   // load address, the alignment, and the size.  This is used when an
 629   // expression refers to an output section which was not actually
 630   // created.  This returns true if the section was found, false
 631   // otherwise.  The only real definition is for
 632   // Output_section_definition.
 633   virtual bool
 634   get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
 635                           uint64_t*) const
 636   { return false; }
 637
 638   // Return the associated Output_section if there is one.
 639   virtual Output_section*
 640   get_output_section() const
 641   { return NULL; }
 642
 643   // Set the section's memory regions.
 644   virtual void
 645   set_memory_region(Memory_region*, bool)
 646   { gold_error(_("Attempt to set a memory region for a non-output section")); }
 647
 648   // Print the element for debugging purposes.
 649   virtual void
 650   print(FILE* f) const = 0;
 651 };
 652
 653 // An assignment in a SECTIONS clause outside of an output section.
 654
 655 class Sections_element_assignment : public Sections_element
 656 {
 657  public:
 658   Sections_element_assignment(const char* name, size_t namelen,
 659                               Expression* val, bool provide, bool hidden)
 660     : assignment_(name, namelen, false, val, provide, hidden)
 661   { }
 662
 663   // Add the symbol to the symbol table.
 664   void
 665   add_symbols_to_table(Symbol_table* symtab)
 666   { this->assignment_.add_to_table(symtab); }
 667
 668   // Finalize the symbol.
 669   void
 670   finalize_symbols(Symbol_table* symtab, const Layout* layout,
 671                    uint64_t* dot_value)
 672   {
 673     this->assignment_.finalize_with_dot(symtab, layout, *dot_value, NULL);
 674   }
 675
 676   // Set the section address.  There is no section here, but if the
 677   // value is absolute, we set the symbol.  This permits us to use
 678   // absolute symbols when setting dot.
 679   void
 680   set_section_addresses(Symbol_table* symtab, Layout* layout,
 681                         uint64_t* dot_value, uint64_t*, uint64_t*)
 682   {
 683     this->assignment_.set_if_absolute(symtab, layout, true, *dot_value, NULL);
 684   }
 685
 686   // Print for debugging.
 687   void
 688   print(FILE* f) const
 689   {
 690     fprintf(f, "  ");
 691     this->assignment_.print(f);
 692   }
 693
 694  private:
 695   Symbol_assignment assignment_;
 696 };
 697
 698 // An assignment to the dot symbol in a SECTIONS clause outside of an
 699 // output section.
 700
 701 class Sections_element_dot_assignment : public Sections_element
 702 {
 703  public:
 704   Sections_element_dot_assignment(Expression* val)
 705     : val_(val)
 706   { }
 707
 708   // Finalize the symbol.
 709   void
 710   finalize_symbols(Symbol_table* symtab, const Layout* layout,
 711                    uint64_t* dot_value)
 712   {
 713     // We ignore the section of the result because outside of an
 714     // output section definition the dot symbol is always considered
 715     // to be absolute.
 716     *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value,
 717                                            NULL, NULL, NULL, false);
 718   }
 719
 720   // Update the dot symbol while setting section addresses.
 721   void
 722   set_section_addresses(Symbol_table* symtab, Layout* layout,
 723                         uint64_t* dot_value, uint64_t* dot_alignment,
 724                         uint64_t* load_address)
 725   {
 726     *dot_value = this->val_->eval_with_dot(symtab, layout, false, *dot_value,
 727                                            NULL, NULL, dot_alignment, false);
 728     *load_address = *dot_value;
 729   }
 730
 731   // Print for debugging.
 732   void
 733   print(FILE* f) const
 734   {
 735     fprintf(f, "  . = ");
 736     this->val_->print(f);
 737     fprintf(f, "\n");
 738   }
 739
 740  private:
 741   Expression* val_;
 742 };
 743
 744 // An assertion in a SECTIONS clause outside of an output section.
 745
 746 class Sections_element_assertion : public Sections_element
 747 {
 748  public:
 749   Sections_element_assertion(Expression* check, const char* message,
 750                              size_t messagelen)
 751     : assertion_(check, message, messagelen)
 752   { }
 753
 754   // Check the assertion.
 755   void
 756   finalize_symbols(Symbol_table* symtab, const Layout* layout, uint64_t*)
 757   { this->assertion_.check(symtab, layout); }
 758
 759   // Print for debugging.
 760   void
 761   print(FILE* f) const
 762   {
 763     fprintf(f, "  ");
 764     this->assertion_.print(f);
 765   }
 766
 767  private:
 768   Script_assertion assertion_;
 769 };
 770
 771 // An element in an output section in a SECTIONS clause.
 772
 773 class Output_section_element
 774 {
 775  public:
 776   // A list of input sections.
 777   typedef std::list<Output_section::Input_section> Input_section_list;
 778
 779   Output_section_element()
 780   { }
 781
 782   virtual ~Output_section_element()
 783   { }
 784
 785   // Return whether this element requires an output section to exist.
 786   virtual bool
 787   needs_output_section() const
 788   { return false; }
 789
 790   // Add any symbol being defined to the symbol table.
 791   virtual void
 792   add_symbols_to_table(Symbol_table*)
 793   { }
 794
 795   // Finalize symbols and check assertions.
 796   virtual void
 797   finalize_symbols(Symbol_table*, const Layout*, uint64_t*, Output_section**)
 798   { }
 799
 800   // Return whether this element matches FILE_NAME and SECTION_NAME.
 801   // The only real implementation is in Output_section_element_input.
 802   virtual bool
 803   match_name(const char*, const char*, bool *) const
 804   { return false; }
 805
 806   // Set section addresses.  This includes applying assignments if the
 807   // expression is an absolute value.
 808   virtual void
 809   set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t,
 810                         uint64_t*, uint64_t*, Output_section**, std::string*,
 811                         Input_section_list*)
 812   { }
 813
 814   // Print the element for debugging purposes.
 815   virtual void
 816   print(FILE* f) const = 0;
 817
 818  protected:
 819   // Return a fill string that is LENGTH bytes long, filling it with
 820   // FILL.
 821   std::string
 822   get_fill_string(const std::string* fill, section_size_type length) const;
 823 };
 824
 825 std::string
 826 Output_section_element::get_fill_string(const std::string* fill,
 827                                         section_size_type length) const
 828 {
 829   std::string this_fill;
 830   this_fill.reserve(length);
 831   while (this_fill.length() + fill->length() <= length)
 832     this_fill += *fill;
 833   if (this_fill.length() < length)
 834     this_fill.append(*fill, 0, length - this_fill.length());
 835   return this_fill;
 836 }
 837
 838 // A symbol assignment in an output section.
 839
 840 class Output_section_element_assignment : public Output_section_element
 841 {
 842  public:
 843   Output_section_element_assignment(const char* name, size_t namelen,
 844                                     Expression* val, bool provide,
 845                                     bool hidden)
 846     : assignment_(name, namelen, false, val, provide, hidden)
 847   { }
 848
 849   // Add the symbol to the symbol table.
 850   void
 851   add_symbols_to_table(Symbol_table* symtab)
 852   { this->assignment_.add_to_table(symtab); }
 853
 854   // Finalize the symbol.
 855   void
 856   finalize_symbols(Symbol_table* symtab, const Layout* layout,
 857                    uint64_t* dot_value, Output_section** dot_section)
 858   {
 859     this->assignment_.finalize_with_dot(symtab, layout, *dot_value,
 860                                         *dot_section);
 861   }
 862
 863   // Set the section address.  There is no section here, but if the
 864   // value is absolute, we set the symbol.  This permits us to use
 865   // absolute symbols when setting dot.
 866   void
 867   set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
 868                         uint64_t, uint64_t* dot_value, uint64_t*,
 869                         Output_section** dot_section, std::string*,
 870                         Input_section_list*)
 871   {
 872     this->assignment_.set_if_absolute(symtab, layout, true, *dot_value,
 873                                       *dot_section);
 874   }
 875
 876   // Print for debugging.
 877   void
 878   print(FILE* f) const
 879   {
 880     fprintf(f, "    ");
 881     this->assignment_.print(f);
 882   }
 883
 884  private:
 885   Symbol_assignment assignment_;
 886 };
 887
 888 // An assignment to the dot symbol in an output section.
 889
 890 class Output_section_element_dot_assignment : public Output_section_element
 891 {
 892  public:
 893   Output_section_element_dot_assignment(Expression* val)
 894     : val_(val)
 895   { }
 896
 897   // An assignment to dot within an output section is enough to force
 898   // the output section to exist.
 899   bool
 900   needs_output_section() const
 901   { return true; }
 902
 903   // Finalize the symbol.
 904   void
 905   finalize_symbols(Symbol_table* symtab, const Layout* layout,
 906                    uint64_t* dot_value, Output_section** dot_section)
 907   {
 908     *dot_value = this->val_->eval_with_dot(symtab, layout, true, *dot_value,
 909                                            *dot_section, dot_section, NULL,
 910                                            true);
 911   }
 912
 913   // Update the dot symbol while setting section addresses.
 914   void
 915   set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
 916                         uint64_t, uint64_t* dot_value, uint64_t*,
 917                         Output_section** dot_section, std::string*,
 918                         Input_section_list*);
 919
 920   // Print for debugging.
 921   void
 922   print(FILE* f) const
 923   {
 924     fprintf(f, "    . = ");
 925     this->val_->print(f);
 926     fprintf(f, "\n");
 927   }
 928
 929  private:
 930   Expression* val_;
 931 };
 932
 933 // Update the dot symbol while setting section addresses.
 934
 935 void
 936 Output_section_element_dot_assignment::set_section_addresses(
 937     Symbol_table* symtab,
 938     Layout* layout,
 939     Output_section* output_section,
 940     uint64_t,
 941     uint64_t* dot_value,
 942     uint64_t* dot_alignment,
 943     Output_section** dot_section,
 944     std::string* fill,
 945     Input_section_list*)
 946 {
 947   uint64_t next_dot = this->val_->eval_with_dot(symtab, layout, false,
 948                                                 *dot_value, *dot_section,
 949                                                 dot_section, dot_alignment,
 950                                                 true);
 951   if (next_dot < *dot_value)
 952     gold_error(_("dot may not move backward"));
 953   if (next_dot > *dot_value && output_section != NULL)
 954     {
 955       section_size_type length = convert_to_section_size_type(next_dot
 956                                                               - *dot_value);
 957       Output_section_data* posd;
 958       if (fill->empty())
 959         posd = new Output_data_zero_fill(length, 0);
 960       else
 961         {
 962           std::string this_fill = this->get_fill_string(fill, length);
 963           posd = new Output_data_const(this_fill, 0);
 964         }
 965       output_section->add_output_section_data(posd);
 966       layout->new_output_section_data_from_script(posd);
 967     }
 968   *dot_value = next_dot;
 969 }
 970
 971 // An assertion in an output section.
 972
 973 class Output_section_element_assertion : public Output_section_element
 974 {
 975  public:
 976   Output_section_element_assertion(Expression* check, const char* message,
 977                                    size_t messagelen)
 978     : assertion_(check, message, messagelen)
 979   { }
 980
 981   void
 982   print(FILE* f) const
 983   {
 984     fprintf(f, "    ");
 985     this->assertion_.print(f);
 986   }
 987
 988  private:
 989   Script_assertion assertion_;
 990 };
 991
 992 // We use a special instance of Output_section_data to handle BYTE,
 993 // SHORT, etc.  This permits forward references to symbols in the
 994 // expressions.
 995
 996 class Output_data_expression : public Output_section_data
 997 {
 998  public:
 999   Output_data_expression(int size, bool is_signed, Expression* val,
1000                          const Symbol_table* symtab, const Layout* layout,
1001                          uint64_t dot_value, Output_section* dot_section)
1002     : Output_section_data(size, 0, true),
1003       is_signed_(is_signed), val_(val), symtab_(symtab),
1004       layout_(layout), dot_value_(dot_value), dot_section_(dot_section)
1005   { }
1006
1007  protected:
1008   // Write the data to the output file.
1009   void
1010   do_write(Output_file*);
1011
1012   // Write the data to a buffer.
1013   void
1014   do_write_to_buffer(unsigned char*);
1015
1016   // Write to a map file.
1017   void
1018   do_print_to_mapfile(Mapfile* mapfile) const
1019   { mapfile->print_output_data(this, _("** expression")); }
1020
1021  private:
1022   template<bool big_endian>
1023   void
1024   endian_write_to_buffer(uint64_t, unsigned char*);
1025
1026   bool is_signed_;
1027   Expression* val_;
1028   const Symbol_table* symtab_;
1029   const Layout* layout_;
1030   uint64_t dot_value_;
1031   Output_section* dot_section_;
1032 };
1033
1034 // Write the data element to the output file.
1035
1036 void
1037 Output_data_expression::do_write(Output_file* of)
1038 {
1039   unsigned char* view = of->get_output_view(this->offset(), this->data_size());
1040   this->write_to_buffer(view);
1041   of->write_output_view(this->offset(), this->data_size(), view);
1042 }
1043
1044 // Write the data element to a buffer.
1045
1046 void
1047 Output_data_expression::do_write_to_buffer(unsigned char* buf)
1048 {
1049   uint64_t val = this->val_->eval_with_dot(this->symtab_, this->layout_,
1050                                            true, this->dot_value_,
1051                                            this->dot_section_, NULL, NULL,
1052                                            false);
1053
1054   if (parameters->target().is_big_endian())
1055     this->endian_write_to_buffer<true>(val, buf);
1056   else
1057     this->endian_write_to_buffer<false>(val, buf);
1058 }
1059
1060 template<bool big_endian>
1061 void
1062 Output_data_expression::endian_write_to_buffer(uint64_t val,
1063                                                unsigned char* buf)
1064 {
1065   switch (this->data_size())
1066     {
1067     case 1:
1068       elfcpp::Swap_unaligned<8, big_endian>::writeval(buf, val);
1069       break;
1070     case 2:
1071       elfcpp::Swap_unaligned<16, big_endian>::writeval(buf, val);
1072       break;
1073     case 4:
1074       elfcpp::Swap_unaligned<32, big_endian>::writeval(buf, val);
1075       break;
1076     case 8:
1077       if (parameters->target().get_size() == 32)
1078         {
1079           val &= 0xffffffff;
1080           if (this->is_signed_ && (val & 0x80000000) != 0)
1081             val |= 0xffffffff00000000LL;
1082         }
1083       elfcpp::Swap_unaligned<64, big_endian>::writeval(buf, val);
1084       break;
1085     default:
1086       gold_unreachable();
1087     }
1088 }
1089
1090 // A data item in an output section.
1091
1092 class Output_section_element_data : public Output_section_element
1093 {
1094  public:
1095   Output_section_element_data(int size, bool is_signed, Expression* val)
1096     : size_(size), is_signed_(is_signed), val_(val)
1097   { }
1098
1099   // If there is a data item, then we must create an output section.
1100   bool
1101   needs_output_section() const
1102   { return true; }
1103
1104   // Finalize symbols--we just need to update dot.
1105   void
1106   finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value,
1107                    Output_section**)
1108   { *dot_value += this->size_; }
1109
1110   // Store the value in the section.
1111   void
1112   set_section_addresses(Symbol_table*, Layout*, Output_section*, uint64_t,
1113                         uint64_t* dot_value, uint64_t*, Output_section**,
1114                         std::string*, Input_section_list*);
1115
1116   // Print for debugging.
1117   void
1118   print(FILE*) const;
1119
1120  private:
1121   // The size in bytes.
1122   int size_;
1123   // Whether the value is signed.
1124   bool is_signed_;
1125   // The value.
1126   Expression* val_;
1127 };
1128
1129 // Store the value in the section.
1130
1131 void
1132 Output_section_element_data::set_section_addresses(
1133     Symbol_table* symtab,
1134     Layout* layout,
1135     Output_section* os,
1136     uint64_t,
1137     uint64_t* dot_value,
1138     uint64_t*,
1139     Output_section** dot_section,
1140     std::string*,
1141     Input_section_list*)
1142 {
1143   gold_assert(os != NULL);
1144   Output_data_expression* expression =
1145     new Output_data_expression(this->size_, this->is_signed_, this->val_,
1146                                symtab, layout, *dot_value, *dot_section);
1147   os->add_output_section_data(expression);
1148   layout->new_output_section_data_from_script(expression);
1149   *dot_value += this->size_;
1150 }
1151
1152 // Print for debugging.
1153
1154 void
1155 Output_section_element_data::print(FILE* f) const
1156 {
1157   const char* s;
1158   switch (this->size_)
1159     {
1160     case 1:
1161       s = "BYTE";
1162       break;
1163     case 2:
1164       s = "SHORT";
1165       break;
1166     case 4:
1167       s = "LONG";
1168       break;
1169     case 8:
1170       if (this->is_signed_)
1171         s = "SQUAD";
1172       else
1173         s = "QUAD";
1174       break;
1175     default:
1176       gold_unreachable();
1177     }
1178   fprintf(f, "    %s(", s);
1179   this->val_->print(f);
1180   fprintf(f, ")\n");
1181 }
1182
1183 // A fill value setting in an output section.
1184
1185 class Output_section_element_fill : public Output_section_element
1186 {
1187  public:
1188   Output_section_element_fill(Expression* val)
1189     : val_(val)
1190   { }
1191
1192   // Update the fill value while setting section addresses.
1193   void
1194   set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
1195                         uint64_t, uint64_t* dot_value, uint64_t*,
1196                         Output_section** dot_section,
1197                         std::string* fill, Input_section_list*)
1198   {
1199     Output_section* fill_section;
1200     uint64_t fill_val = this->val_->eval_with_dot(symtab, layout, false,
1201                                                   *dot_value, *dot_section,
1202                                                   &fill_section, NULL, false);
1203     if (fill_section != NULL)
1204       gold_warning(_("fill value is not absolute"));
1205     // FIXME: The GNU linker supports fill values of arbitrary length.
1206     unsigned char fill_buff[4];
1207     elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val);
1208     fill->assign(reinterpret_cast<char*>(fill_buff), 4);
1209   }
1210
1211   // Print for debugging.
1212   void
1213   print(FILE* f) const
1214   {
1215     fprintf(f, "    FILL(");
1216     this->val_->print(f);
1217     fprintf(f, ")\n");
1218   }
1219
1220  private:
1221   // The new fill value.
1222   Expression* val_;
1223 };
1224
1225 // An input section specification in an output section
1226
1227 class Output_section_element_input : public Output_section_element
1228 {
1229  public:
1230   Output_section_element_input(const Input_section_spec* spec, bool keep);
1231
1232   // Finalize symbols--just update the value of the dot symbol.
1233   void
1234   finalize_symbols(Symbol_table*, const Layout*, uint64_t* dot_value,
1235                    Output_section** dot_section)
1236   {
1237     *dot_value = this->final_dot_value_;
1238     *dot_section = this->final_dot_section_;
1239   }
1240
1241   // See whether we match FILE_NAME and SECTION_NAME as an input section.
1242   // If we do then also indicate whether the section should be KEPT.
1243   bool
1244   match_name(const char* file_name, const char* section_name, bool* keep) const;
1245
1246   // Set the section address.
1247   void
1248   set_section_addresses(Symbol_table* symtab, Layout* layout, Output_section*,
1249                         uint64_t subalign, uint64_t* dot_value, uint64_t*,
1250                         Output_section**, std::string* fill,
1251                         Input_section_list*);
1252
1253   // Print for debugging.
1254   void
1255   print(FILE* f) const;
1256
1257  private:
1258   // An input section pattern.
1259   struct Input_section_pattern
1260   {
1261     std::string pattern;
1262     bool pattern_is_wildcard;
1263     Sort_wildcard sort;
1264
1265     Input_section_pattern(const char* patterna, size_t patternlena,
1266                           Sort_wildcard sorta)
1267       : pattern(patterna, patternlena),
1268         pattern_is_wildcard(is_wildcard_string(this->pattern.c_str())),
1269         sort(sorta)
1270     { }
1271   };
1272
1273   typedef std::vector<Input_section_pattern> Input_section_patterns;
1274
1275   // Filename_exclusions is a pair of filename pattern and a bool
1276   // indicating whether the filename is a wildcard.
1277   typedef std::vector<std::pair<std::string, bool> > Filename_exclusions;
1278
1279   // Return whether STRING matches PATTERN, where IS_WILDCARD_PATTERN
1280   // indicates whether this is a wildcard pattern.
1281   static inline bool
1282   match(const char* string, const char* pattern, bool is_wildcard_pattern)
1283   {
1284     return (is_wildcard_pattern
1285             ? fnmatch(pattern, string, 0) == 0
1286             : strcmp(string, pattern) == 0);
1287   }
1288
1289   // See if we match a file name.
1290   bool
1291   match_file_name(const char* file_name) const;
1292
1293   // The file name pattern.  If this is the empty string, we match all
1294   // files.
1295   std::string filename_pattern_;
1296   // Whether the file name pattern is a wildcard.
1297   bool filename_is_wildcard_;
1298   // How the file names should be sorted.  This may only be
1299   // SORT_WILDCARD_NONE or SORT_WILDCARD_BY_NAME.
1300   Sort_wildcard filename_sort_;
1301   // The list of file names to exclude.
1302   Filename_exclusions filename_exclusions_;
1303   // The list of input section patterns.
1304   Input_section_patterns input_section_patterns_;
1305   // Whether to keep this section when garbage collecting.
1306   bool keep_;
1307   // The value of dot after including all matching sections.
1308   uint64_t final_dot_value_;
1309   // The section where dot is defined after including all matching
1310   // sections.
1311   Output_section* final_dot_section_;
1312 };
1313
1314 // Construct Output_section_element_input.  The parser records strings
1315 // as pointers into a copy of the script file, which will go away when
1316 // parsing is complete.  We make sure they are in std::string objects.
1317
1318 Output_section_element_input::Output_section_element_input(
1319     const Input_section_spec* spec,
1320     bool keep)
1321   : filename_pattern_(),
1322     filename_is_wildcard_(false),
1323     filename_sort_(spec->file.sort),
1324     filename_exclusions_(),
1325     input_section_patterns_(),
1326     keep_(keep),
1327     final_dot_value_(0),
1328     final_dot_section_(NULL)
1329 {
1330   // The filename pattern "*" is common, and matches all files.  Turn
1331   // it into the empty string.
1332   if (spec->file.name.length != 1 || spec->file.name.value[0] != '*')
1333     this->filename_pattern_.assign(spec->file.name.value,
1334                                    spec->file.name.length);
1335   this->filename_is_wildcard_ = is_wildcard_string(this->filename_pattern_.c_str());
1336
1337   if (spec->input_sections.exclude != NULL)
1338     {
1339       for (String_list::const_iterator p =
1340              spec->input_sections.exclude->begin();
1341            p != spec->input_sections.exclude->end();
1342            ++p)
1343         {
1344           bool is_wildcard = is_wildcard_string((*p).c_str());
1345           this->filename_exclusions_.push_back(std::make_pair(*p,
1346                                                               is_wildcard));
1347         }
1348     }
1349
1350   if (spec->input_sections.sections != NULL)
1351     {
1352       Input_section_patterns& isp(this->input_section_patterns_);
1353       for (String_sort_list::const_iterator p =
1354              spec->input_sections.sections->begin();
1355            p != spec->input_sections.sections->end();
1356            ++p)
1357         isp.push_back(Input_section_pattern(p->name.value, p->name.length,
1358                                             p->sort));
1359     }
1360 }
1361
1362 // See whether we match FILE_NAME.
1363
1364 bool
1365 Output_section_element_input::match_file_name(const char* file_name) const
1366 {
1367   if (!this->filename_pattern_.empty())
1368     {
1369       // If we were called with no filename, we refuse to match a
1370       // pattern which requires a file name.
1371       if (file_name == NULL)
1372         return false;
1373
1374       if (!match(file_name, this->filename_pattern_.c_str(),
1375                  this->filename_is_wildcard_))
1376         return false;
1377     }
1378
1379   if (file_name != NULL)
1380     {
1381       // Now we have to see whether FILE_NAME matches one of the
1382       // exclusion patterns, if any.
1383       for (Filename_exclusions::const_iterator p =
1384              this->filename_exclusions_.begin();
1385            p != this->filename_exclusions_.end();
1386            ++p)
1387         {
1388           if (match(file_name, p->first.c_str(), p->second))
1389             return false;
1390         }
1391     }
1392
1393   return true;
1394 }
1395
1396 // See whether we match FILE_NAME and SECTION_NAME.  If we do then
1397 // KEEP indicates whether the section should survive garbage collection.
1398
1399 bool
1400 Output_section_element_input::match_name(const char* file_name,
1401                                          const char* section_name,
1402                                          bool *keep) const
1403 {
1404   if (!this->match_file_name(file_name))
1405     return false;
1406
1407   *keep = this->keep_;
1408
1409   // If there are no section name patterns, then we match.
1410   if (this->input_section_patterns_.empty())
1411     return true;
1412
1413   // See whether we match the section name patterns.
1414   for (Input_section_patterns::const_iterator p =
1415          this->input_section_patterns_.begin();
1416        p != this->input_section_patterns_.end();
1417        ++p)
1418     {
1419       if (match(section_name, p->pattern.c_str(), p->pattern_is_wildcard))
1420         return true;
1421     }
1422
1423   // We didn't match any section names, so we didn't match.
1424   return false;
1425 }
1426
1427 // Information we use to sort the input sections.
1428
1429 class Input_section_info
1430 {
1431  public:
1432   Input_section_info(const Output_section::Input_section& input_section)
1433     : input_section_(input_section), section_name_(),
1434       size_(0), addralign_(1)
1435   { }
1436
1437   // Return the simple input section.
1438   const Output_section::Input_section&
1439   input_section() const
1440   { return this->input_section_; }
1441
1442   // Return the object.
1443   Relobj*
1444   relobj() const
1445   { return this->input_section_.relobj(); }
1446
1447   // Return the section index.
1448   unsigned int
1449   shndx()
1450   { return this->input_section_.shndx(); }
1451
1452   // Return the section name.
1453   const std::string&
1454   section_name() const
1455   { return this->section_name_; }
1456
1457   // Set the section name.
1458   void
1459   set_section_name(const std::string name)
1460   { this->section_name_ = name; }
1461
1462   // Return the section size.
1463   uint64_t
1464   size() const
1465   { return this->size_; }
1466
1467   // Set the section size.
1468   void
1469   set_size(uint64_t size)
1470   { this->size_ = size; }
1471
1472   // Return the address alignment.
1473   uint64_t
1474   addralign() const
1475   { return this->addralign_; }
1476
1477   // Set the address alignment.
1478   void
1479   set_addralign(uint64_t addralign)
1480   { this->addralign_ = addralign; }
1481
1482  private:
1483   // Input section, can be a relaxed section.
1484   Output_section::Input_section input_section_;
1485   // Name of the section.
1486   std::string section_name_;
1487   // Section size.
1488   uint64_t size_;
1489   // Address alignment.
1490   uint64_t addralign_;
1491 };
1492
1493 // A class to sort the input sections.
1494
1495 class Input_section_sorter
1496 {
1497  public:
1498   Input_section_sorter(Sort_wildcard filename_sort, Sort_wildcard section_sort)
1499     : filename_sort_(filename_sort), section_sort_(section_sort)
1500   { }
1501
1502   bool
1503   operator()(const Input_section_info&, const Input_section_info&) const;
1504
1505  private:
1506   Sort_wildcard filename_sort_;
1507   Sort_wildcard section_sort_;
1508 };
1509
1510 bool
1511 Input_section_sorter::operator()(const Input_section_info& isi1,
1512                                  const Input_section_info& isi2) const
1513 {
1514   if (this->section_sort_ == SORT_WILDCARD_BY_NAME
1515       || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1516       || (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME
1517           && isi1.addralign() == isi2.addralign()))
1518     {
1519       if (isi1.section_name() != isi2.section_name())
1520         return isi1.section_name() < isi2.section_name();
1521     }
1522   if (this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT
1523       || this->section_sort_ == SORT_WILDCARD_BY_NAME_BY_ALIGNMENT
1524       || this->section_sort_ == SORT_WILDCARD_BY_ALIGNMENT_BY_NAME)
1525     {
1526       if (isi1.addralign() != isi2.addralign())
1527         return isi1.addralign() < isi2.addralign();
1528     }
1529   if (this->filename_sort_ == SORT_WILDCARD_BY_NAME)
1530     {
1531       if (isi1.relobj()->name() != isi2.relobj()->name())
1532         return (isi1.relobj()->name() < isi2.relobj()->name());
1533     }
1534
1535   // Otherwise we leave them in the same order.
1536   return false;
1537 }
1538
1539 // Set the section address.  Look in INPUT_SECTIONS for sections which
1540 // match this spec, sort them as specified, and add them to the output
1541 // section.
1542
1543 void
1544 Output_section_element_input::set_section_addresses(
1545     Symbol_table*,
1546     Layout* layout,
1547     Output_section* output_section,
1548     uint64_t subalign,
1549     uint64_t* dot_value,
1550     uint64_t*,
1551     Output_section** dot_section,
1552     std::string* fill,
1553     Input_section_list* input_sections)
1554 {
1555   // We build a list of sections which match each
1556   // Input_section_pattern.
1557
1558   typedef std::vector<std::vector<Input_section_info> > Matching_sections;
1559   size_t input_pattern_count = this->input_section_patterns_.size();
1560   if (input_pattern_count == 0)
1561     input_pattern_count = 1;
1562   Matching_sections matching_sections(input_pattern_count);
1563
1564   // Look through the list of sections for this output section.  Add
1565   // each one which matches to one of the elements of
1566   // MATCHING_SECTIONS.
1567
1568   Input_section_list::iterator p = input_sections->begin();
1569   while (p != input_sections->end())
1570     {
1571       Relobj* relobj = p->relobj();
1572       unsigned int shndx = p->shndx();
1573       Input_section_info isi(*p);
1574
1575       // Calling section_name and section_addralign is not very
1576       // efficient.
1577
1578       // Lock the object so that we can get information about the
1579       // section.  This is OK since we know we are single-threaded
1580       // here.
1581       {
1582         const Task* task = reinterpret_cast<const Task*>(-1);
1583         Task_lock_obj<Object> tl(task, relobj);
1584
1585         isi.set_section_name(relobj->section_name(shndx));
1586         if (p->is_relaxed_input_section())
1587           {
1588             // We use current data size because relaxed section sizes may not
1589             // have finalized yet.
1590             isi.set_size(p->relaxed_input_section()->current_data_size());
1591             isi.set_addralign(p->relaxed_input_section()->addralign());
1592           }
1593         else
1594           {
1595             isi.set_size(relobj->section_size(shndx));
1596             isi.set_addralign(relobj->section_addralign(shndx));
1597           }
1598       }
1599
1600       if (!this->match_file_name(relobj->name().c_str()))
1601         ++p;
1602       else if (this->input_section_patterns_.empty())
1603         {
1604           matching_sections[0].push_back(isi);
1605           p = input_sections->erase(p);
1606         }
1607       else
1608         {
1609           size_t i;
1610           for (i = 0; i < input_pattern_count; ++i)
1611             {
1612               const Input_section_pattern&
1613                 isp(this->input_section_patterns_[i]);
1614               if (match(isi.section_name().c_str(), isp.pattern.c_str(),
1615                         isp.pattern_is_wildcard))
1616                 break;
1617             }
1618
1619           if (i >= this->input_section_patterns_.size())
1620             ++p;
1621           else
1622             {
1623               matching_sections[i].push_back(isi);
1624               p = input_sections->erase(p);
1625             }
1626         }
1627     }
1628
1629   // Look through MATCHING_SECTIONS.  Sort each one as specified,
1630   // using a stable sort so that we get the default order when
1631   // sections are otherwise equal.  Add each input section to the
1632   // output section.
1633
1634   uint64_t dot = *dot_value;
1635   for (size_t i = 0; i < input_pattern_count; ++i)
1636     {
1637       if (matching_sections[i].empty())
1638         continue;
1639
1640       gold_assert(output_section != NULL);
1641
1642       const Input_section_pattern& isp(this->input_section_patterns_[i]);
1643       if (isp.sort != SORT_WILDCARD_NONE
1644           || this->filename_sort_ != SORT_WILDCARD_NONE)
1645         std::stable_sort(matching_sections[i].begin(),
1646                          matching_sections[i].end(),
1647                          Input_section_sorter(this->filename_sort_,
1648                                               isp.sort));
1649
1650       for (std::vector<Input_section_info>::const_iterator p =
1651              matching_sections[i].begin();
1652            p != matching_sections[i].end();
1653            ++p)
1654         {
1655           // Override the original address alignment if SUBALIGN is specified
1656           // and is greater than the original alignment.  We need to make a
1657           // copy of the input section to modify the alignment.
1658           Output_section::Input_section sis(p->input_section());
1659
1660           uint64_t this_subalign = sis.addralign();
1661           if (!sis.is_input_section())
1662             sis.output_section_data()->finalize_data_size();
1663           uint64_t data_size = sis.data_size();
1664           if (this_subalign < subalign)
1665             {
1666               this_subalign = subalign;
1667               sis.set_addralign(subalign);
1668             }
1669
1670           uint64_t address = align_address(dot, this_subalign);
1671
1672           if (address > dot && !fill->empty())
1673             {
1674               section_size_type length =
1675                 convert_to_section_size_type(address - dot);
1676               std::string this_fill = this->get_fill_string(fill, length);
1677               Output_section_data* posd = new Output_data_const(this_fill, 0);
1678               output_section->add_output_section_data(posd);
1679               layout->new_output_section_data_from_script(posd);
1680             }
1681
1682           output_section->add_script_input_section(sis);
1683           dot = address + data_size;
1684         }
1685     }
1686
1687   // An SHF_TLS/SHT_NOBITS section does not take up any
1688   // address space.
1689   if (output_section == NULL
1690       || (output_section->flags() & elfcpp::SHF_TLS) == 0
1691       || output_section->type() != elfcpp::SHT_NOBITS)
1692     *dot_value = dot;
1693
1694   this->final_dot_value_ = *dot_value;
1695   this->final_dot_section_ = *dot_section;
1696 }
1697
1698 // Print for debugging.
1699
1700 void
1701 Output_section_element_input::print(FILE* f) const
1702 {
1703   fprintf(f, "    ");
1704
1705   if (this->keep_)
1706     fprintf(f, "KEEP(");
1707
1708   if (!this->filename_pattern_.empty())
1709     {
1710       bool need_close_paren = false;
1711       switch (this->filename_sort_)
1712         {
1713         case SORT_WILDCARD_NONE:
1714           break;
1715         case SORT_WILDCARD_BY_NAME:
1716           fprintf(f, "SORT_BY_NAME(");
1717           need_close_paren = true;
1718           break;
1719         default:
1720           gold_unreachable();
1721         }
1722
1723       fprintf(f, "%s", this->filename_pattern_.c_str());
1724
1725       if (need_close_paren)
1726         fprintf(f, ")");
1727     }
1728
1729   if (!this->input_section_patterns_.empty()
1730       || !this->filename_exclusions_.empty())
1731     {
1732       fprintf(f, "(");
1733
1734       bool need_space = false;
1735       if (!this->filename_exclusions_.empty())
1736         {
1737           fprintf(f, "EXCLUDE_FILE(");
1738           bool need_comma = false;
1739           for (Filename_exclusions::const_iterator p =
1740                  this->filename_exclusions_.begin();
1741                p != this->filename_exclusions_.end();
1742                ++p)
1743             {
1744               if (need_comma)
1745                 fprintf(f, ", ");
1746               fprintf(f, "%s", p->first.c_str());
1747               need_comma = true;
1748             }
1749           fprintf(f, ")");
1750           need_space = true;
1751         }
1752
1753       for (Input_section_patterns::const_iterator p =
1754              this->input_section_patterns_.begin();
1755            p != this->input_section_patterns_.end();
1756            ++p)
1757         {
1758           if (need_space)
1759             fprintf(f, " ");
1760
1761           int close_parens = 0;
1762           switch (p->sort)
1763             {
1764             case SORT_WILDCARD_NONE:
1765               break;
1766             case SORT_WILDCARD_BY_NAME:
1767               fprintf(f, "SORT_BY_NAME(");
1768               close_parens = 1;
1769               break;
1770             case SORT_WILDCARD_BY_ALIGNMENT:
1771               fprintf(f, "SORT_BY_ALIGNMENT(");
1772               close_parens = 1;
1773               break;
1774             case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT:
1775               fprintf(f, "SORT_BY_NAME(SORT_BY_ALIGNMENT(");
1776               close_parens = 2;
1777               break;
1778             case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME:
1779               fprintf(f, "SORT_BY_ALIGNMENT(SORT_BY_NAME(");
1780               close_parens = 2;
1781               break;
1782             default:
1783               gold_unreachable();
1784             }
1785
1786           fprintf(f, "%s", p->pattern.c_str());
1787
1788           for (int i = 0; i < close_parens; ++i)
1789             fprintf(f, ")");
1790
1791           need_space = true;
1792         }
1793
1794       fprintf(f, ")");
1795     }
1796
1797   if (this->keep_)
1798     fprintf(f, ")");
1799
1800   fprintf(f, "\n");
1801 }
1802
1803 // An output section.
1804
1805 class Output_section_definition : public Sections_element
1806 {
1807  public:
1808   typedef Output_section_element::Input_section_list Input_section_list;
1809
1810   Output_section_definition(const char* name, size_t namelen,
1811                             const Parser_output_section_header* header);
1812
1813   // Finish the output section with the information in the trailer.
1814   void
1815   finish(const Parser_output_section_trailer* trailer);
1816
1817   // Add a symbol to be defined.
1818   void
1819   add_symbol_assignment(const char* name, size_t length, Expression* value,
1820                         bool provide, bool hidden);
1821
1822   // Add an assignment to the special dot symbol.
1823   void
1824   add_dot_assignment(Expression* value);
1825
1826   // Add an assertion.
1827   void
1828   add_assertion(Expression* check, const char* message, size_t messagelen);
1829
1830   // Add a data item to the current output section.
1831   void
1832   add_data(int size, bool is_signed, Expression* val);
1833
1834   // Add a setting for the fill value.
1835   void
1836   add_fill(Expression* val);
1837
1838   // Add an input section specification.
1839   void
1840   add_input_section(const Input_section_spec* spec, bool keep);
1841
1842   // Return whether the output section is relro.
1843   bool
1844   is_relro() const
1845   { return this->is_relro_; }
1846
1847   // Record that the output section is relro.
1848   void
1849   set_is_relro()
1850   { this->is_relro_ = true; }
1851
1852   // Create any required output sections.
1853   void
1854   create_sections(Layout*);
1855
1856   // Add any symbols being defined to the symbol table.
1857   void
1858   add_symbols_to_table(Symbol_table* symtab);
1859
1860   // Finalize symbols and check assertions.
1861   void
1862   finalize_symbols(Symbol_table*, const Layout*, uint64_t*);
1863
1864   // Return the output section name to use for an input file name and
1865   // section name.
1866   const char*
1867   output_section_name(const char* file_name, const char* section_name,
1868                       Output_section***, Script_sections::Section_type*,
1869                       bool*);
1870
1871   // Initialize OSP with an output section.
1872   void
1873   orphan_section_init(Orphan_section_placement* osp,
1874                       Script_sections::Elements_iterator p)
1875   { osp->output_section_init(this->name_, this->output_section_, p); }
1876
1877   // Set the section address.
1878   void
1879   set_section_addresses(Symbol_table* symtab, Layout* layout,
1880                         uint64_t* dot_value, uint64_t*,
1881                         uint64_t* load_address);
1882
1883   // Check a constraint (ONLY_IF_RO, etc.) on an output section.  If
1884   // this section is constrained, and the input sections do not match,
1885   // return the constraint, and set *POSD.
1886   Section_constraint
1887   check_constraint(Output_section_definition** posd);
1888
1889   // See if this is the alternate output section for a constrained
1890   // output section.  If it is, transfer the Output_section and return
1891   // true.  Otherwise return false.
1892   bool
1893   alternate_constraint(Output_section_definition*, Section_constraint);
1894
1895   // Get the list of segments to use for an allocated section when
1896   // using a PHDRS clause.
1897   Output_section*
1898   allocate_to_segment(String_list** phdrs_list, bool* orphan);
1899
1900   // Look for an output section by name and return the address, the
1901   // load address, the alignment, and the size.  This is used when an
1902   // expression refers to an output section which was not actually
1903   // created.  This returns true if the section was found, false
1904   // otherwise.
1905   bool
1906   get_output_section_info(const char*, uint64_t*, uint64_t*, uint64_t*,
1907                           uint64_t*) const;
1908
1909   // Return the associated Output_section if there is one.
1910   Output_section*
1911   get_output_section() const
1912   { return this->output_section_; }
1913
1914   // Print the contents to the FILE.  This is for debugging.
1915   void
1916   print(FILE*) const;
1917
1918   // Return the output section type if specified or Script_sections::ST_NONE.
1919   Script_sections::Section_type
1920   section_type() const;
1921
1922   // Store the memory region to use.
1923   void
1924   set_memory_region(Memory_region*, bool set_vma);
1925
1926   void
1927   set_section_vma(Expression* address)
1928   { this->address_ = address; }
1929
1930   void
1931   set_section_lma(Expression* address)
1932   { this->load_address_ = address; }
1933
1934   const std::string&
1935   get_section_name() const
1936   { return this->name_; }
1937
1938  private:
1939   static const char*
1940   script_section_type_name(Script_section_type);
1941
1942   typedef std::vector<Output_section_element*> Output_section_elements;
1943
1944   // The output section name.
1945   std::string name_;
1946   // The address.  This may be NULL.
1947   Expression* address_;
1948   // The load address.  This may be NULL.
1949   Expression* load_address_;
1950   // The alignment.  This may be NULL.
1951   Expression* align_;
1952   // The input section alignment.  This may be NULL.
1953   Expression* subalign_;
1954   // The constraint, if any.
1955   Section_constraint constraint_;
1956   // The fill value.  This may be NULL.
1957   Expression* fill_;
1958   // The list of segments this section should go into.  This may be
1959   // NULL.
1960   String_list* phdrs_;
1961   // The list of elements defining the section.
1962   Output_section_elements elements_;
1963   // The Output_section created for this definition.  This will be
1964   // NULL if none was created.
1965   Output_section* output_section_;
1966   // The address after it has been evaluated.
1967   uint64_t evaluated_address_;
1968   // The load address after it has been evaluated.
1969   uint64_t evaluated_load_address_;
1970   // The alignment after it has been evaluated.
1971   uint64_t evaluated_addralign_;
1972   // The output section is relro.
1973   bool is_relro_;
1974   // The output section type if specified.
1975   enum Script_section_type script_section_type_;
1976 };
1977
1978 // Constructor.
1979
1980 Output_section_definition::Output_section_definition(
1981     const char* name,
1982     size_t namelen,
1983     const Parser_output_section_header* header)
1984   : name_(name, namelen),
1985     address_(header->address),
1986     load_address_(header->load_address),
1987     align_(header->align),
1988     subalign_(header->subalign),
1989     constraint_(header->constraint),
1990     fill_(NULL),
1991     phdrs_(NULL),
1992     elements_(),
1993     output_section_(NULL),
1994     evaluated_address_(0),
1995     evaluated_load_address_(0),
1996     evaluated_addralign_(0),
1997     is_relro_(false),
1998     script_section_type_(header->section_type)
1999 {
2000 }
2001
2002 // Finish an output section.
2003
2004 void
2005 Output_section_definition::finish(const Parser_output_section_trailer* trailer)
2006 {
2007   this->fill_ = trailer->fill;
2008   this->phdrs_ = trailer->phdrs;
2009 }
2010
2011 // Add a symbol to be defined.
2012
2013 void
2014 Output_section_definition::add_symbol_assignment(const char* name,
2015                                                  size_t length,
2016                                                  Expression* value,
2017                                                  bool provide,
2018                                                  bool hidden)
2019 {
2020   Output_section_element* p = new Output_section_element_assignment(name,
2021                                                                     length,
2022                                                                     value,
2023                                                                     provide,
2024                                                                     hidden);
2025   this->elements_.push_back(p);
2026 }
2027
2028 // Add an assignment to the special dot symbol.
2029
2030 void
2031 Output_section_definition::add_dot_assignment(Expression* value)
2032 {
2033   Output_section_element* p = new Output_section_element_dot_assignment(value);
2034   this->elements_.push_back(p);
2035 }
2036
2037 // Add an assertion.
2038
2039 void
2040 Output_section_definition::add_assertion(Expression* check,
2041                                          const char* message,
2042                                          size_t messagelen)
2043 {
2044   Output_section_element* p = new Output_section_element_assertion(check,
2045                                                                    message,
2046                                                                    messagelen);
2047   this->elements_.push_back(p);
2048 }
2049
2050 // Add a data item to the current output section.
2051
2052 void
2053 Output_section_definition::add_data(int size, bool is_signed, Expression* val)
2054 {
2055   Output_section_element* p = new Output_section_element_data(size, is_signed,
2056                                                               val);
2057   this->elements_.push_back(p);
2058 }
2059
2060 // Add a setting for the fill value.
2061
2062 void
2063 Output_section_definition::add_fill(Expression* val)
2064 {
2065   Output_section_element* p = new Output_section_element_fill(val);
2066   this->elements_.push_back(p);
2067 }
2068
2069 // Add an input section specification.
2070
2071 void
2072 Output_section_definition::add_input_section(const Input_section_spec* spec,
2073                                              bool keep)
2074 {
2075   Output_section_element* p = new Output_section_element_input(spec, keep);
2076   this->elements_.push_back(p);
2077 }
2078
2079 // Create any required output sections.  We need an output section if
2080 // there is a data statement here.
2081
2082 void
2083 Output_section_definition::create_sections(Layout* layout)
2084 {
2085   if (this->output_section_ != NULL)
2086     return;
2087   for (Output_section_elements::const_iterator p = this->elements_.begin();
2088        p != this->elements_.end();
2089        ++p)
2090     {
2091       if ((*p)->needs_output_section())
2092         {
2093           const char* name = this->name_.c_str();
2094           this->output_section_ =
2095             layout->make_output_section_for_script(name, this->section_type());
2096           return;
2097         }
2098     }
2099 }
2100
2101 // Add any symbols being defined to the symbol table.
2102
2103 void
2104 Output_section_definition::add_symbols_to_table(Symbol_table* symtab)
2105 {
2106   for (Output_section_elements::iterator p = this->elements_.begin();
2107        p != this->elements_.end();
2108        ++p)
2109     (*p)->add_symbols_to_table(symtab);
2110 }
2111
2112 // Finalize symbols and check assertions.
2113
2114 void
2115 Output_section_definition::finalize_symbols(Symbol_table* symtab,
2116                                             const Layout* layout,
2117                                             uint64_t* dot_value)
2118 {
2119   if (this->output_section_ != NULL)
2120     *dot_value = this->output_section_->address();
2121   else
2122     {
2123       uint64_t address = *dot_value;
2124       if (this->address_ != NULL)
2125         {
2126           address = this->address_->eval_with_dot(symtab, layout, true,
2127                                                   *dot_value, NULL,
2128                                                   NULL, NULL, false);
2129         }
2130       if (this->align_ != NULL)
2131         {
2132           uint64_t align = this->align_->eval_with_dot(symtab, layout, true,
2133                                                        *dot_value, NULL,
2134                                                        NULL, NULL, false);
2135           address = align_address(address, align);
2136         }
2137       *dot_value = address;
2138     }
2139
2140   Output_section* dot_section = this->output_section_;
2141   for (Output_section_elements::iterator p = this->elements_.begin();
2142        p != this->elements_.end();
2143        ++p)
2144     (*p)->finalize_symbols(symtab, layout, dot_value, &dot_section);
2145 }
2146
2147 // Return the output section name to use for an input section name.
2148
2149 const char*
2150 Output_section_definition::output_section_name(
2151     const char* file_name,
2152     const char* section_name,
2153     Output_section*** slot,
2154     Script_sections::Section_type* psection_type,
2155     bool* keep)
2156 {
2157   // Ask each element whether it matches NAME.
2158   for (Output_section_elements::const_iterator p = this->elements_.begin();
2159        p != this->elements_.end();
2160        ++p)
2161     {
2162       if ((*p)->match_name(file_name, section_name, keep))
2163         {
2164           // We found a match for NAME, which means that it should go
2165           // into this output section.
2166           *slot = &this->output_section_;
2167           *psection_type = this->section_type();
2168           return this->name_.c_str();
2169         }
2170     }
2171
2172   // We don't know about this section name.
2173   return NULL;
2174 }
2175
2176 // Return true if memory from START to START + LENGTH is contained
2177 // within a memory region.
2178
2179 bool
2180 Script_sections::block_in_region(Symbol_table* symtab, Layout* layout,
2181                                  uint64_t start, uint64_t length) const
2182 {
2183   if (this->memory_regions_ == NULL)
2184     return false;
2185
2186   for (Memory_regions::const_iterator mr = this->memory_regions_->begin();
2187        mr != this->memory_regions_->end();
2188        ++mr)
2189     {
2190       uint64_t s = (*mr)->start_address()->eval(symtab, layout, false);
2191       uint64_t l = (*mr)->length()->eval(symtab, layout, false);
2192
2193       if (s <= start
2194           && (s + l) >= (start + length))
2195         return true;
2196     }
2197
2198   return false;
2199 }
2200
2201 // Find a memory region that should be used by a given output SECTION.
2202 // If provided set PREVIOUS_SECTION_RETURN to point to the last section
2203 // that used the return memory region.
2204
2205 Memory_region*
2206 Script_sections::find_memory_region(
2207     Output_section_definition* section,
2208     bool find_vma_region,
2209     Output_section_definition** previous_section_return)
2210 {
2211   if (previous_section_return != NULL)
2212     * previous_section_return = NULL;
2213
2214   // Walk the memory regions specified in this script, if any.
2215   if (this->memory_regions_ == NULL)
2216     return NULL;
2217
2218   // The /DISCARD/ section never gets assigned to any region.
2219   if (section->get_section_name() == "/DISCARD/")
2220     return NULL;
2221
2222   Memory_region* first_match = NULL;
2223
2224   // First check to see if a region has been assigned to this section.
2225   for (Memory_regions::const_iterator mr = this->memory_regions_->begin();
2226        mr != this->memory_regions_->end();
2227        ++mr)
2228     {
2229       if (find_vma_region)
2230         {
2231           for (Memory_region::Section_list::const_iterator s =
2232                  (*mr)->get_vma_section_list_start();
2233                s != (*mr)->get_vma_section_list_end();
2234                ++s)
2235             if ((*s) == section)
2236               {
2237                 (*mr)->set_last_section(section);
2238                 return *mr;
2239               }
2240         }
2241       else
2242         {
2243           for (Memory_region::Section_list::const_iterator s =
2244                  (*mr)->get_lma_section_list_start();
2245                s != (*mr)->get_lma_section_list_end();
2246                ++s)
2247             if ((*s) == section)
2248               {
2249                 (*mr)->set_last_section(section);
2250                 return *mr;
2251               }
2252         }
2253
2254       // Make a note of the first memory region whose attributes
2255       // are compatible with the section.  If we do not find an
2256       // explicit region assignment, then we will return this region.
2257       Output_section* out_sec = section->get_output_section();
2258       if (first_match == NULL
2259           && out_sec != NULL
2260           && (*mr)->attributes_compatible(out_sec->flags(),
2261                                           out_sec->type()))
2262         first_match = *mr;
2263     }
2264
2265   // With LMA computations, if an explicit region has not been specified then
2266   // we will want to set the difference between the VMA and the LMA of the
2267   // section were searching for to be the same as the difference between the
2268   // VMA and LMA of the last section to be added to first matched region.
2269   // Hence, if it was asked for, we return a pointer to the last section
2270   // known to be used by the first matched region.
2271   if (first_match != NULL
2272       && previous_section_return != NULL)
2273     *previous_section_return = first_match->get_last_section();
2274
2275   return first_match;
2276 }
2277
2278 // Set the section address.  Note that the OUTPUT_SECTION_ field will
2279 // be NULL if no input sections were mapped to this output section.
2280 // We still have to adjust dot and process symbol assignments.
2281
2282 void
2283 Output_section_definition::set_section_addresses(Symbol_table* symtab,
2284                                                  Layout* layout,
2285                                                  uint64_t* dot_value,
2286                                                  uint64_t* dot_alignment,
2287                                                  uint64_t* load_address)
2288 {
2289   Memory_region* vma_region = NULL;
2290   Memory_region* lma_region = NULL;
2291   Script_sections* script_sections =
2292     layout->script_options()->script_sections();
2293   uint64_t address;
2294   uint64_t old_dot_value = *dot_value;
2295   uint64_t old_load_address = *load_address;
2296
2297   // Decide the start address for the section.  The algorithm is:
2298   // 1) If an address has been specified in a linker script, use that.
2299   // 2) Otherwise if a memory region has been specified for the section,
2300   //    use the next free address in the region.
2301   // 3) Otherwise if memory regions have been specified find the first
2302   //    region whose attributes are compatible with this section and
2303   //    install it into that region.
2304   // 4) Otherwise use the current location counter.
2305
2306   if (this->output_section_ != NULL
2307       // Check for --section-start.
2308       && parameters->options().section_start(this->output_section_->name(),
2309                                              &address))
2310     ;
2311   else if (this->address_ == NULL)
2312     {
2313       vma_region = script_sections->find_memory_region(this, true, NULL);
2314
2315       if (vma_region != NULL)
2316         address = vma_region->get_current_address()->eval(symtab, layout,
2317                                                           false);
2318       else
2319         address = *dot_value;
2320     }
2321   else
2322     address = this->address_->eval_with_dot(symtab, layout, true,
2323                                             *dot_value, NULL, NULL,
2324                                             dot_alignment, false);
2325   uint64_t align;
2326   if (this->align_ == NULL)
2327     {
2328       if (this->output_section_ == NULL)
2329         align = 0;
2330       else
2331         align = this->output_section_->addralign();
2332     }
2333   else
2334     {
2335       Output_section* align_section;
2336       align = this->align_->eval_with_dot(symtab, layout, true, *dot_value,
2337                                           NULL, &align_section, NULL, false);
2338       if (align_section != NULL)
2339         gold_warning(_("alignment of section %s is not absolute"),
2340                      this->name_.c_str());
2341       if (this->output_section_ != NULL)
2342         this->output_section_->set_addralign(align);
2343     }
2344
2345   address = align_address(address, align);
2346
2347   uint64_t start_address = address;
2348
2349   *dot_value = address;
2350
2351   // Except for NOLOAD sections, the address of non-SHF_ALLOC sections is
2352   // forced to zero, regardless of what the linker script wants.
2353   if (this->output_section_ != NULL
2354       && ((this->output_section_->flags() & elfcpp::SHF_ALLOC) != 0
2355           || this->output_section_->is_noload()))
2356     this->output_section_->set_address(address);
2357
2358   this->evaluated_address_ = address;
2359   this->evaluated_addralign_ = align;
2360
2361   uint64_t laddr;
2362
2363   if (this->load_address_ == NULL)
2364     {
2365       Output_section_definition* previous_section;
2366
2367       // Determine if an LMA region has been set for this section.
2368       lma_region = script_sections->find_memory_region(this, false,
2369                                                        &previous_section);
2370
2371       if (lma_region != NULL)
2372         {
2373           if (previous_section == NULL)
2374             // The LMA address was explicitly set to the given region.
2375             laddr = lma_region->get_current_address()->eval(symtab, layout,
2376                                                             false);
2377           else
2378             {
2379               // We are not going to use the discovered lma_region, so
2380               // make sure that we do not update it in the code below.
2381               lma_region = NULL;
2382
2383               if (this->address_ != NULL || previous_section == this)
2384                 {
2385                   // Either an explicit VMA address has been set, or an
2386                   // explicit VMA region has been set, so set the LMA equal to
2387                   // the VMA.
2388                   laddr = address;
2389                 }
2390               else
2391                 {
2392                   // The LMA address was not explicitly or implicitly set.
2393                   //
2394                   // We have been given the first memory region that is
2395                   // compatible with the current section and a pointer to the
2396                   // last section to use this region.  Set the LMA of this
2397                   // section so that the difference between its' VMA and LMA
2398                   // is the same as the difference between the VMA and LMA of
2399                   // the last section in the given region.
2400                   laddr = address + (previous_section->evaluated_load_address_
2401                                      - previous_section->evaluated_address_);
2402                 }
2403             }
2404
2405           if (this->output_section_ != NULL)
2406             this->output_section_->set_load_address(laddr);
2407         }
2408       else
2409         {
2410           // Do not set the load address of the output section, if one exists.
2411           // This allows future sections to determine what the load address
2412           // should be.  If none is ever set, it will default to being the
2413           // same as the vma address.
2414           laddr = address;
2415         }
2416     }
2417   else
2418     {
2419       laddr = this->load_address_->eval_with_dot(symtab, layout, true,
2420                                                  *dot_value,
2421                                                  this->output_section_,
2422                                                  NULL, NULL, false);
2423       if (this->output_section_ != NULL)
2424         this->output_section_->set_load_address(laddr);
2425     }
2426
2427   this->evaluated_load_address_ = laddr;
2428
2429   uint64_t subalign;
2430   if (this->subalign_ == NULL)
2431     subalign = 0;
2432   else
2433     {
2434       Output_section* subalign_section;
2435       subalign = this->subalign_->eval_with_dot(symtab, layout, true,
2436                                                 *dot_value, NULL,
2437                                                 &subalign_section, NULL,
2438                                                 false);
2439       if (subalign_section != NULL)
2440         gold_warning(_("subalign of section %s is not absolute"),
2441                      this->name_.c_str());
2442     }
2443
2444   std::string fill;
2445   if (this->fill_ != NULL)
2446     {
2447       // FIXME: The GNU linker supports fill values of arbitrary
2448       // length.
2449       Output_section* fill_section;
2450       uint64_t fill_val = this->fill_->eval_with_dot(symtab, layout, true,
2451                                                      *dot_value,
2452                                                      NULL, &fill_section,
2453                                                      NULL, false);
2454       if (fill_section != NULL)
2455         gold_warning(_("fill of section %s is not absolute"),
2456                      this->name_.c_str());
2457       unsigned char fill_buff[4];
2458       elfcpp::Swap_unaligned<32, true>::writeval(fill_buff, fill_val);
2459       fill.assign(reinterpret_cast<char*>(fill_buff), 4);
2460     }
2461
2462   Input_section_list input_sections;
2463   if (this->output_section_ != NULL)
2464     {
2465       // Get the list of input sections attached to this output
2466       // section.  This will leave the output section with only
2467       // Output_section_data entries.
2468       address += this->output_section_->get_input_sections(address,
2469                                                            fill,
2470                                                            &input_sections);
2471       *dot_value = address;
2472     }
2473
2474   Output_section* dot_section = this->output_section_;
2475   for (Output_section_elements::iterator p = this->elements_.begin();
2476        p != this->elements_.end();
2477        ++p)
2478     (*p)->set_section_addresses(symtab, layout, this->output_section_,
2479                                 subalign, dot_value, dot_alignment,
2480                                 &dot_section, &fill, &input_sections);
2481
2482   gold_assert(input_sections.empty());
2483
2484   if (vma_region != NULL)
2485     {
2486       // Update the VMA region being used by the section now that we know how
2487       // big it is.  Use the current address in the region, rather than
2488       // start_address because that might have been aligned upwards and we
2489       // need to allow for the padding.
2490       Expression* addr = vma_region->get_current_address();
2491       uint64_t size = *dot_value - addr->eval(symtab, layout, false);
2492
2493       vma_region->increment_offset(this->get_section_name(), size,
2494                                    symtab, layout);
2495     }
2496
2497   // If the LMA region is different from the VMA region, then increment the
2498   // offset there as well.  Note that we use the same "dot_value -
2499   // start_address" formula that is used in the load_address assignment below.
2500   if (lma_region != NULL && lma_region != vma_region)
2501     lma_region->increment_offset(this->get_section_name(),
2502                                  *dot_value - start_address,
2503                                  symtab, layout);
2504
2505   // Compute the load address for the following section.
2506   if (this->output_section_ == NULL)
2507     *load_address = *dot_value;
2508   else if (this->load_address_ == NULL)
2509     {
2510       if (lma_region == NULL)
2511         *load_address = *dot_value;
2512       else
2513         *load_address =
2514           lma_region->get_current_address()->eval(symtab, layout, false);
2515     }
2516   else
2517     *load_address = (this->output_section_->load_address()
2518                      + (*dot_value - start_address));
2519
2520   if (this->output_section_ != NULL)
2521     {
2522       if (this->is_relro_)
2523         this->output_section_->set_is_relro();
2524       else
2525         this->output_section_->clear_is_relro();
2526
2527       // If this is a NOLOAD section, keep dot and load address unchanged.
2528       if (this->output_section_->is_noload())
2529         {
2530           *dot_value = old_dot_value;
2531           *load_address = old_load_address;
2532         }
2533     }
2534 }
2535
2536 // Check a constraint (ONLY_IF_RO, etc.) on an output section.  If
2537 // this section is constrained, and the input sections do not match,
2538 // return the constraint, and set *POSD.
2539
2540 Section_constraint
2541 Output_section_definition::check_constraint(Output_section_definition** posd)
2542 {
2543   switch (this->constraint_)
2544     {
2545     case CONSTRAINT_NONE:
2546       return CONSTRAINT_NONE;
2547
2548     case CONSTRAINT_ONLY_IF_RO:
2549       if (this->output_section_ != NULL
2550           && (this->output_section_->flags() & elfcpp::SHF_WRITE) != 0)
2551         {
2552           *posd = this;
2553           return CONSTRAINT_ONLY_IF_RO;
2554         }
2555       return CONSTRAINT_NONE;
2556
2557     case CONSTRAINT_ONLY_IF_RW:
2558       if (this->output_section_ != NULL
2559           && (this->output_section_->flags() & elfcpp::SHF_WRITE) == 0)
2560         {
2561           *posd = this;
2562           return CONSTRAINT_ONLY_IF_RW;
2563         }
2564       return CONSTRAINT_NONE;
2565
2566     case CONSTRAINT_SPECIAL:
2567       if (this->output_section_ != NULL)
2568         gold_error(_("SPECIAL constraints are not implemented"));
2569       return CONSTRAINT_NONE;
2570
2571     default:
2572       gold_unreachable();
2573     }
2574 }
2575
2576 // See if this is the alternate output section for a constrained
2577 // output section.  If it is, transfer the Output_section and return
2578 // true.  Otherwise return false.
2579
2580 bool
2581 Output_section_definition::alternate_constraint(
2582     Output_section_definition* posd,
2583     Section_constraint constraint)
2584 {
2585   if (this->name_ != posd->name_)
2586     return false;
2587
2588   switch (constraint)
2589     {
2590     case CONSTRAINT_ONLY_IF_RO:
2591       if (this->constraint_ != CONSTRAINT_ONLY_IF_RW)
2592         return false;
2593       break;
2594
2595     case CONSTRAINT_ONLY_IF_RW:
2596       if (this->constraint_ != CONSTRAINT_ONLY_IF_RO)
2597         return false;
2598       break;
2599
2600     default:
2601       gold_unreachable();
2602     }
2603
2604   // We have found the alternate constraint.  We just need to move
2605   // over the Output_section.  When constraints are used properly,
2606   // THIS should not have an output_section pointer, as all the input
2607   // sections should have matched the other definition.
2608
2609   if (this->output_section_ != NULL)
2610     gold_error(_("mismatched definition for constrained sections"));
2611
2612   this->output_section_ = posd->output_section_;
2613   posd->output_section_ = NULL;
2614
2615   if (this->is_relro_)
2616     this->output_section_->set_is_relro();
2617   else
2618     this->output_section_->clear_is_relro();
2619
2620   return true;
2621 }
2622
2623 // Get the list of segments to use for an allocated section when using
2624 // a PHDRS clause.
2625
2626 Output_section*
2627 Output_section_definition::allocate_to_segment(String_list** phdrs_list,
2628                                                bool* orphan)
2629 {
2630   // Update phdrs_list even if we don't have an output section. It
2631   // might be used by the following sections.
2632   if (this->phdrs_ != NULL)
2633     *phdrs_list = this->phdrs_;
2634
2635   if (this->output_section_ == NULL)
2636     return NULL;
2637   if ((this->output_section_->flags() & elfcpp::SHF_ALLOC) == 0)
2638     return NULL;
2639   *orphan = false;
2640   return this->output_section_;
2641 }
2642
2643 // Look for an output section by name and return the address, the load
2644 // address, the alignment, and the size.  This is used when an
2645 // expression refers to an output section which was not actually
2646 // created.  This returns true if the section was found, false
2647 // otherwise.
2648
2649 bool
2650 Output_section_definition::get_output_section_info(const char* name,
2651                                                    uint64_t* address,
2652                                                    uint64_t* load_address,
2653                                                    uint64_t* addralign,
2654                                                    uint64_t* size) const
2655 {
2656   if (this->name_ != name)
2657     return false;
2658
2659   if (this->output_section_ != NULL)
2660     {
2661       *address = this->output_section_->address();
2662       if (this->output_section_->has_load_address())
2663         *load_address = this->output_section_->load_address();
2664       else
2665         *load_address = *address;
2666       *addralign = this->output_section_->addralign();
2667       *size = this->output_section_->current_data_size();
2668     }
2669   else
2670     {
2671       *address = this->evaluated_address_;
2672       *load_address = this->evaluated_load_address_;
2673       *addralign = this->evaluated_addralign_;
2674       *size = 0;
2675     }
2676
2677   return true;
2678 }
2679
2680 // Print for debugging.
2681
2682 void
2683 Output_section_definition::print(FILE* f) const
2684 {
2685   fprintf(f, "  %s ", this->name_.c_str());
2686
2687   if (this->address_ != NULL)
2688     {
2689       this->address_->print(f);
2690       fprintf(f, " ");
2691     }
2692
2693   if (this->script_section_type_ != SCRIPT_SECTION_TYPE_NONE)
2694       fprintf(f, "(%s) ",
2695               this->script_section_type_name(this->script_section_type_));
2696
2697   fprintf(f, ": ");
2698
2699   if (this->load_address_ != NULL)
2700     {
2701       fprintf(f, "AT(");
2702       this->load_address_->print(f);
2703       fprintf(f, ") ");
2704     }
2705
2706   if (this->align_ != NULL)
2707     {
2708       fprintf(f, "ALIGN(");
2709       this->align_->print(f);
2710       fprintf(f, ") ");
2711     }
2712
2713   if (this->subalign_ != NULL)
2714     {
2715       fprintf(f, "SUBALIGN(");
2716       this->subalign_->print(f);
2717       fprintf(f, ") ");
2718     }
2719
2720   fprintf(f, "{\n");
2721
2722   for (Output_section_elements::const_iterator p = this->elements_.begin();
2723        p != this->elements_.end();
2724        ++p)
2725     (*p)->print(f);
2726
2727   fprintf(f, "  }");
2728
2729   if (this->fill_ != NULL)
2730     {
2731       fprintf(f, " = ");
2732       this->fill_->print(f);
2733     }
2734
2735   if (this->phdrs_ != NULL)
2736     {
2737       for (String_list::const_iterator p = this->phdrs_->begin();
2738            p != this->phdrs_->end();
2739            ++p)
2740         fprintf(f, " :%s", p->c_str());
2741     }
2742
2743   fprintf(f, "\n");
2744 }
2745
2746 Script_sections::Section_type
2747 Output_section_definition::section_type() const
2748 {
2749   switch (this->script_section_type_)
2750     {
2751     case SCRIPT_SECTION_TYPE_NONE:
2752       return Script_sections::ST_NONE;
2753     case SCRIPT_SECTION_TYPE_NOLOAD:
2754       return Script_sections::ST_NOLOAD;
2755     case SCRIPT_SECTION_TYPE_COPY:
2756     case SCRIPT_SECTION_TYPE_DSECT:
2757     case SCRIPT_SECTION_TYPE_INFO:
2758     case SCRIPT_SECTION_TYPE_OVERLAY:
2759       // There are not really support so we treat them as ST_NONE.  The
2760       // parse should have issued errors for them already.
2761       return Script_sections::ST_NONE;
2762     default:
2763       gold_unreachable();
2764     }
2765 }
2766
2767 // Return the name of a script section type.
2768
2769 const char*
2770 Output_section_definition::script_section_type_name(
2771     Script_section_type script_section_type)
2772 {
2773   switch (script_section_type)
2774     {
2775     case SCRIPT_SECTION_TYPE_NONE:
2776       return "NONE";
2777     case SCRIPT_SECTION_TYPE_NOLOAD:
2778       return "NOLOAD";
2779     case SCRIPT_SECTION_TYPE_DSECT:
2780       return "DSECT";
2781     case SCRIPT_SECTION_TYPE_COPY:
2782       return "COPY";
2783     case SCRIPT_SECTION_TYPE_INFO:
2784       return "INFO";
2785     case SCRIPT_SECTION_TYPE_OVERLAY:
2786       return "OVERLAY";
2787     default:
2788       gold_unreachable();
2789     }
2790 }
2791
2792 void
2793 Output_section_definition::set_memory_region(Memory_region* mr, bool set_vma)
2794 {
2795   gold_assert(mr != NULL);
2796   // Add the current section to the specified region's list.
2797   mr->add_section(this, set_vma);
2798 }
2799
2800 // An output section created to hold orphaned input sections.  These
2801 // do not actually appear in linker scripts.  However, for convenience
2802 // when setting the output section addresses, we put a marker to these
2803 // sections in the appropriate place in the list of SECTIONS elements.
2804
2805 class Orphan_output_section : public Sections_element
2806 {
2807  public:
2808   Orphan_output_section(Output_section* os)
2809     : os_(os)
2810   { }
2811
2812   // Return whether the orphan output section is relro.  We can just
2813   // check the output section because we always set the flag, if
2814   // needed, just after we create the Orphan_output_section.
2815   bool
2816   is_relro() const
2817   { return this->os_->is_relro(); }
2818
2819   // Initialize OSP with an output section.  This should have been
2820   // done already.
2821   void
2822   orphan_section_init(Orphan_section_placement*,
2823                       Script_sections::Elements_iterator)
2824   { gold_unreachable(); }
2825
2826   // Set section addresses.
2827   void
2828   set_section_addresses(Symbol_table*, Layout*, uint64_t*, uint64_t*,
2829                         uint64_t*);
2830
2831   // Get the list of segments to use for an allocated section when
2832   // using a PHDRS clause.
2833   Output_section*
2834   allocate_to_segment(String_list**, bool*);
2835
2836   // Return the associated Output_section.
2837   Output_section*
2838   get_output_section() const
2839   { return this->os_; }
2840
2841   // Print for debugging.
2842   void
2843   print(FILE* f) const
2844   {
2845     fprintf(f, "  marker for orphaned output section %s\n",
2846             this->os_->name());
2847   }
2848
2849  private:
2850   Output_section* os_;
2851 };
2852
2853 // Set section addresses.
2854
2855 void
2856 Orphan_output_section::set_section_addresses(Symbol_table*, Layout*,
2857                                              uint64_t* dot_value,
2858                                              uint64_t*,
2859                                              uint64_t* load_address)
2860 {
2861   typedef std::list<Output_section::Input_section> Input_section_list;
2862
2863   bool have_load_address = *load_address != *dot_value;
2864
2865   uint64_t address = *dot_value;
2866   address = align_address(address, this->os_->addralign());
2867
2868   // For a relocatable link, all orphan sections are put at
2869   // address 0.  In general we expect all sections to be at
2870   // address 0 for a relocatable link, but we permit the linker
2871   // script to override that for specific output sections.
2872   if (parameters->options().relocatable())
2873     {
2874       address = 0;
2875       *load_address = 0;
2876       have_load_address = false;
2877     }
2878
2879   if ((this->os_->flags() & elfcpp::SHF_ALLOC) != 0)
2880     {
2881       this->os_->set_address(address);
2882       if (have_load_address)
2883         this->os_->set_load_address(align_address(*load_address,
2884                                                   this->os_->addralign()));
2885     }
2886
2887   Input_section_list input_sections;
2888   address += this->os_->get_input_sections(address, "", &input_sections);
2889
2890   for (Input_section_list::iterator p = input_sections.begin();
2891        p != input_sections.end();
2892        ++p)
2893     {
2894       uint64_t addralign = p->addralign();
2895       if (!p->is_input_section())
2896         p->output_section_data()->finalize_data_size();
2897       uint64_t size = p->data_size();
2898       address = align_address(address, addralign);
2899       this->os_->add_script_input_section(*p);
2900       address += size;
2901     }
2902
2903   // An SHF_TLS/SHT_NOBITS section does not take up any address space.
2904   if (this->os_ == NULL
2905       || (this->os_->flags() & elfcpp::SHF_TLS) == 0
2906       || this->os_->type() != elfcpp::SHT_NOBITS)
2907     {
2908       if (!have_load_address)
2909         *load_address = address;
2910       else
2911         *load_address += address - *dot_value;
2912
2913       *dot_value = address;
2914     }
2915 }
2916
2917 // Get the list of segments to use for an allocated section when using
2918 // a PHDRS clause.  If this is an allocated section, return the
2919 // Output_section.  We don't change the list of segments.
2920
2921 Output_section*
2922 Orphan_output_section::allocate_to_segment(String_list**, bool* orphan)
2923 {
2924   if ((this->os_->flags() & elfcpp::SHF_ALLOC) == 0)
2925     return NULL;
2926   *orphan = true;
2927   return this->os_;
2928 }
2929
2930 // Class Phdrs_element.  A program header from a PHDRS clause.
2931
2932 class Phdrs_element
2933 {
2934  public:
2935   Phdrs_element(const char* name, size_t namelen, unsigned int type,
2936                 bool includes_filehdr, bool includes_phdrs,
2937                 bool is_flags_valid, unsigned int flags,
2938                 Expression* load_address)
2939     : name_(name, namelen), type_(type), includes_filehdr_(includes_filehdr),
2940       includes_phdrs_(includes_phdrs), is_flags_valid_(is_flags_valid),
2941       flags_(flags), load_address_(load_address), load_address_value_(0),
2942       segment_(NULL)
2943   { }
2944
2945   // Return the name of this segment.
2946   const std::string&
2947   name() const
2948   { return this->name_; }
2949
2950   // Return the type of the segment.
2951   unsigned int
2952   type() const
2953   { return this->type_; }
2954
2955   // Whether to include the file header.
2956   bool
2957   includes_filehdr() const
2958   { return this->includes_filehdr_; }
2959
2960   // Whether to include the program headers.
2961   bool
2962   includes_phdrs() const
2963   { return this->includes_phdrs_; }
2964
2965   // Return whether there is a load address.
2966   bool
2967   has_load_address() const
2968   { return this->load_address_ != NULL; }
2969
2970   // Evaluate the load address expression if there is one.
2971   void
2972   eval_load_address(Symbol_table* symtab, Layout* layout)
2973   {
2974     if (this->load_address_ != NULL)
2975       this->load_address_value_ = this->load_address_->eval(symtab, layout,
2976                                                             true);
2977   }
2978
2979   // Return the load address.
2980   uint64_t
2981   load_address() const
2982   {
2983     gold_assert(this->load_address_ != NULL);
2984     return this->load_address_value_;
2985   }
2986
2987   // Create the segment.
2988   Output_segment*
2989   create_segment(Layout* layout)
2990   {
2991     this->segment_ = layout->make_output_segment(this->type_, this->flags_);
2992     return this->segment_;
2993   }
2994
2995   // Return the segment.
2996   Output_segment*
2997   segment()
2998   { return this->segment_; }
2999
3000   // Release the segment.
3001   void
3002   release_segment()
3003   { this->segment_ = NULL; }
3004
3005   // Set the segment flags if appropriate.
3006   void
3007   set_flags_if_valid()
3008   {
3009     if (this->is_flags_valid_)
3010       this->segment_->set_flags(this->flags_);
3011   }
3012
3013   // Print for debugging.
3014   void
3015   print(FILE*) const;
3016
3017  private:
3018   // The name used in the script.
3019   std::string name_;
3020   // The type of the segment (PT_LOAD, etc.).
3021   unsigned int type_;
3022   // Whether this segment includes the file header.
3023   bool includes_filehdr_;
3024   // Whether this segment includes the section headers.
3025   bool includes_phdrs_;
3026   // Whether the flags were explicitly specified.
3027   bool is_flags_valid_;
3028   // The flags for this segment (PF_R, etc.) if specified.
3029   unsigned int flags_;
3030   // The expression for the load address for this segment.  This may
3031   // be NULL.
3032   Expression* load_address_;
3033   // The actual load address from evaluating the expression.
3034   uint64_t load_address_value_;
3035   // The segment itself.
3036   Output_segment* segment_;
3037 };
3038
3039 // Print for debugging.
3040
3041 void
3042 Phdrs_element::print(FILE* f) const
3043 {
3044   fprintf(f, "  %s 0x%x", this->name_.c_str(), this->type_);
3045   if (this->includes_filehdr_)
3046     fprintf(f, " FILEHDR");
3047   if (this->includes_phdrs_)
3048     fprintf(f, " PHDRS");
3049   if (this->is_flags_valid_)
3050     fprintf(f, " FLAGS(%u)", this->flags_);
3051   if (this->load_address_ != NULL)
3052     {
3053       fprintf(f, " AT(");
3054       this->load_address_->print(f);
3055       fprintf(f, ")");
3056     }
3057   fprintf(f, ";\n");
3058 }
3059
3060 // Add a memory region.
3061
3062 void
3063 Script_sections::add_memory_region(const char* name, size_t namelen,
3064                                    unsigned int attributes,
3065                                    Expression* start, Expression* length)
3066 {
3067   if (this->memory_regions_ == NULL)
3068     this->memory_regions_ = new Memory_regions();
3069   else if (this->find_memory_region(name, namelen))
3070     {
3071       gold_error(_("region '%.*s' already defined"), static_cast<int>(namelen),
3072                   name);
3073       // FIXME: Add a GOLD extension to allow multiple regions with the same
3074       // name.  This would amount to a single region covering disjoint blocks
3075       // of memory, which is useful for embedded devices.
3076     }
3077
3078   // FIXME: Check the length and start values.  Currently we allow
3079   // non-constant expressions for these values, whereas LD does not.
3080
3081   // FIXME: Add a GOLD extension to allow NEGATIVE LENGTHS.  This would
3082   // describe a region that packs from the end address going down, rather
3083   // than the start address going up.  This would be useful for embedded
3084   // devices.
3085
3086   this->memory_regions_->push_back(new Memory_region(name, namelen, attributes,
3087                                                      start, length));
3088 }
3089
3090 // Find a memory region.
3091
3092 Memory_region*
3093 Script_sections::find_memory_region(const char* name, size_t namelen)
3094 {
3095   if (this->memory_regions_ == NULL)
3096     return NULL;
3097
3098   for (Memory_regions::const_iterator m = this->memory_regions_->begin();
3099        m != this->memory_regions_->end();
3100        ++m)
3101     if ((*m)->name_match(name, namelen))
3102       return *m;
3103
3104   return NULL;
3105 }
3106
3107 // Find a memory region's origin.
3108
3109 Expression*
3110 Script_sections::find_memory_region_origin(const char* name, size_t namelen)
3111 {
3112   Memory_region* mr = find_memory_region(name, namelen);
3113   if (mr == NULL)
3114     return NULL;
3115
3116   return mr->start_address();
3117 }
3118
3119 // Find a memory region's length.
3120
3121 Expression*
3122 Script_sections::find_memory_region_length(const char* name, size_t namelen)
3123 {
3124   Memory_region* mr = find_memory_region(name, namelen);
3125   if (mr == NULL)
3126     return NULL;
3127
3128   return mr->length();
3129 }
3130
3131 // Set the memory region to use for the current section.
3132
3133 void
3134 Script_sections::set_memory_region(Memory_region* mr, bool set_vma)
3135 {
3136   gold_assert(!this->sections_elements_->empty());
3137   this->sections_elements_->back()->set_memory_region(mr, set_vma);
3138 }
3139
3140 // Class Script_sections.
3141
3142 Script_sections::Script_sections()
3143   : saw_sections_clause_(false),
3144     in_sections_clause_(false),
3145     sections_elements_(NULL),
3146     output_section_(NULL),
3147     memory_regions_(NULL),
3148     phdrs_elements_(NULL),
3149     orphan_section_placement_(NULL),
3150     data_segment_align_start_(),
3151     saw_data_segment_align_(false),
3152     saw_relro_end_(false),
3153     saw_segment_start_expression_(false)
3154 {
3155 }
3156
3157 // Start a SECTIONS clause.
3158
3159 void
3160 Script_sections::start_sections()
3161 {
3162   gold_assert(!this->in_sections_clause_ && this->output_section_ == NULL);
3163   this->saw_sections_clause_ = true;
3164   this->in_sections_clause_ = true;
3165   if (this->sections_elements_ == NULL)
3166     this->sections_elements_ = new Sections_elements;
3167 }
3168
3169 // Finish a SECTIONS clause.
3170
3171 void
3172 Script_sections::finish_sections()
3173 {
3174   gold_assert(this->in_sections_clause_ && this->output_section_ == NULL);
3175   this->in_sections_clause_ = false;
3176 }
3177
3178 // Add a symbol to be defined.
3179
3180 void
3181 Script_sections::add_symbol_assignment(const char* name, size_t length,
3182                                        Expression* val, bool provide,
3183                                        bool hidden)
3184 {
3185   if (this->output_section_ != NULL)
3186     this->output_section_->add_symbol_assignment(name, length, val,
3187                                                  provide, hidden);
3188   else
3189     {
3190       Sections_element* p = new Sections_element_assignment(name, length,
3191                                                             val, provide,
3192                                                             hidden);
3193       this->sections_elements_->push_back(p);
3194     }
3195 }
3196
3197 // Add an assignment to the special dot symbol.
3198
3199 void
3200 Script_sections::add_dot_assignment(Expression* val)
3201 {
3202   if (this->output_section_ != NULL)
3203     this->output_section_->add_dot_assignment(val);
3204   else
3205     {
3206       // The GNU linker permits assignments to . to appears outside of
3207       // a SECTIONS clause, and treats it as appearing inside, so
3208       // sections_elements_ may be NULL here.
3209       if (this->sections_elements_ == NULL)
3210         {
3211           this->sections_elements_ = new Sections_elements;
3212           this->saw_sections_clause_ = true;
3213         }
3214
3215       Sections_element* p = new Sections_element_dot_assignment(val);
3216       this->sections_elements_->push_back(p);
3217     }
3218 }
3219
3220 // Add an assertion.
3221
3222 void
3223 Script_sections::add_assertion(Expression* check, const char* message,
3224                                size_t messagelen)
3225 {
3226   if (this->output_section_ != NULL)
3227     this->output_section_->add_assertion(check, message, messagelen);
3228   else
3229     {
3230       Sections_element* p = new Sections_element_assertion(check, message,
3231                                                            messagelen);
3232       this->sections_elements_->push_back(p);
3233     }
3234 }
3235
3236 // Start processing entries for an output section.
3237
3238 void
3239 Script_sections::start_output_section(
3240     const char* name,
3241     size_t namelen,
3242     const Parser_output_section_header* header)
3243 {
3244   Output_section_definition* posd = new Output_section_definition(name,
3245                                                                   namelen,
3246                                                                   header);
3247   this->sections_elements_->push_back(posd);
3248   gold_assert(this->output_section_ == NULL);
3249   this->output_section_ = posd;
3250 }
3251
3252 // Stop processing entries for an output section.
3253
3254 void
3255 Script_sections::finish_output_section(
3256     const Parser_output_section_trailer* trailer)
3257 {
3258   gold_assert(this->output_section_ != NULL);
3259   this->output_section_->finish(trailer);
3260   this->output_section_ = NULL;
3261 }
3262
3263 // Add a data item to the current output section.
3264
3265 void
3266 Script_sections::add_data(int size, bool is_signed, Expression* val)
3267 {
3268   gold_assert(this->output_section_ != NULL);
3269   this->output_section_->add_data(size, is_signed, val);
3270 }
3271
3272 // Add a fill value setting to the current output section.
3273
3274 void
3275 Script_sections::add_fill(Expression* val)
3276 {
3277   gold_assert(this->output_section_ != NULL);
3278   this->output_section_->add_fill(val);
3279 }
3280
3281 // Add an input section specification to the current output section.
3282
3283 void
3284 Script_sections::add_input_section(const Input_section_spec* spec, bool keep)
3285 {
3286   gold_assert(this->output_section_ != NULL);
3287   this->output_section_->add_input_section(spec, keep);
3288 }
3289
3290 // This is called when we see DATA_SEGMENT_ALIGN.  It means that any
3291 // subsequent output sections may be relro.
3292
3293 void
3294 Script_sections::data_segment_align()
3295 {
3296   if (this->saw_data_segment_align_)
3297     gold_error(_("DATA_SEGMENT_ALIGN may only appear once in a linker script"));
3298   gold_assert(!this->sections_elements_->empty());
3299   Sections_elements::iterator p = this->sections_elements_->end();
3300   --p;
3301   this->data_segment_align_start_ = p;
3302   this->saw_data_segment_align_ = true;
3303 }
3304
3305 // This is called when we see DATA_SEGMENT_RELRO_END.  It means that
3306 // any output sections seen since DATA_SEGMENT_ALIGN are relro.
3307
3308 void
3309 Script_sections::data_segment_relro_end()
3310 {
3311   if (this->saw_relro_end_)
3312     gold_error(_("DATA_SEGMENT_RELRO_END may only appear once "
3313                  "in a linker script"));
3314   this->saw_relro_end_ = true;
3315
3316   if (!this->saw_data_segment_align_)
3317     gold_error(_("DATA_SEGMENT_RELRO_END must follow DATA_SEGMENT_ALIGN"));
3318   else
3319     {
3320       Sections_elements::iterator p = this->data_segment_align_start_;
3321       for (++p; p != this->sections_elements_->end(); ++p)
3322         (*p)->set_is_relro();
3323     }
3324 }
3325
3326 // Create any required sections.
3327
3328 void
3329 Script_sections::create_sections(Layout* layout)
3330 {
3331   if (!this->saw_sections_clause_)
3332     return;
3333   for (Sections_elements::iterator p = this->sections_elements_->begin();
3334        p != this->sections_elements_->end();
3335        ++p)
3336     (*p)->create_sections(layout);
3337 }
3338
3339 // Add any symbols we are defining to the symbol table.
3340
3341 void
3342 Script_sections::add_symbols_to_table(Symbol_table* symtab)
3343 {
3344   if (!this->saw_sections_clause_)
3345     return;
3346   for (Sections_elements::iterator p = this->sections_elements_->begin();
3347        p != this->sections_elements_->end();
3348        ++p)
3349     (*p)->add_symbols_to_table(symtab);
3350 }
3351
3352 // Finalize symbols and check assertions.
3353
3354 void
3355 Script_sections::finalize_symbols(Symbol_table* symtab, const Layout* layout)
3356 {
3357   if (!this->saw_sections_clause_)
3358     return;
3359   uint64_t dot_value = 0;
3360   for (Sections_elements::iterator p = this->sections_elements_->begin();
3361        p != this->sections_elements_->end();
3362        ++p)
3363     (*p)->finalize_symbols(symtab, layout, &dot_value);
3364 }
3365
3366 // Return the name of the output section to use for an input file name
3367 // and section name.
3368
3369 const char*
3370 Script_sections::output_section_name(
3371     const char* file_name,
3372     const char* section_name,
3373     Output_section*** output_section_slot,
3374     Script_sections::Section_type* psection_type,
3375     bool* keep)
3376 {
3377   for (Sections_elements::const_iterator p = this->sections_elements_->begin();
3378        p != this->sections_elements_->end();
3379        ++p)
3380     {
3381       const char* ret = (*p)->output_section_name(file_name, section_name,
3382                                                   output_section_slot,
3383                                                   psection_type, keep);
3384
3385       if (ret != NULL)
3386         {
3387           // The special name /DISCARD/ means that the input section
3388           // should be discarded.
3389           if (strcmp(ret, "/DISCARD/") == 0)
3390             {
3391               *output_section_slot = NULL;
3392               *psection_type = Script_sections::ST_NONE;
3393               return NULL;
3394             }
3395           return ret;
3396         }
3397     }
3398
3399   // If we couldn't find a mapping for the name, the output section
3400   // gets the name of the input section.
3401
3402   *output_section_slot = NULL;
3403   *psection_type = Script_sections::ST_NONE;
3404
3405   return section_name;
3406 }
3407
3408 // Place a marker for an orphan output section into the SECTIONS
3409 // clause.
3410
3411 void
3412 Script_sections::place_orphan(Output_section* os)
3413 {
3414   Orphan_section_placement* osp = this->orphan_section_placement_;
3415   if (osp == NULL)
3416     {
3417       // Initialize the Orphan_section_placement structure.
3418       osp = new Orphan_section_placement();
3419       for (Sections_elements::iterator p = this->sections_elements_->begin();
3420            p != this->sections_elements_->end();
3421            ++p)
3422         (*p)->orphan_section_init(osp, p);
3423       gold_assert(!this->sections_elements_->empty());
3424       Sections_elements::iterator last = this->sections_elements_->end();
3425       --last;
3426       osp->last_init(last);
3427       this->orphan_section_placement_ = osp;
3428     }
3429
3430   Orphan_output_section* orphan = new Orphan_output_section(os);
3431
3432   // Look for where to put ORPHAN.
3433   Sections_elements::iterator* where;
3434   if (osp->find_place(os, &where))
3435     {
3436       if ((**where)->is_relro())
3437         os->set_is_relro();
3438       else
3439         os->clear_is_relro();
3440
3441       // We want to insert ORPHAN after *WHERE, and then update *WHERE
3442       // so that the next one goes after this one.
3443       Sections_elements::iterator p = *where;
3444       gold_assert(p != this->sections_elements_->end());
3445       ++p;
3446       *where = this->sections_elements_->insert(p, orphan);
3447     }
3448   else
3449     {
3450       os->clear_is_relro();
3451       // We don't have a place to put this orphan section.  Put it,
3452       // and all other sections like it, at the end, but before the
3453       // sections which always come at the end.
3454       Sections_elements::iterator last = osp->last_place();
3455       *where = this->sections_elements_->insert(last, orphan);
3456     }
3457 }
3458
3459 // Set the addresses of all the output sections.  Walk through all the
3460 // elements, tracking the dot symbol.  Apply assignments which set
3461 // absolute symbol values, in case they are used when setting dot.
3462 // Fill in data statement values.  As we find output sections, set the
3463 // address, set the address of all associated input sections, and
3464 // update dot.  Return the segment which should hold the file header
3465 // and segment headers, if any.
3466
3467 Output_segment*
3468 Script_sections::set_section_addresses(Symbol_table* symtab, Layout* layout)
3469 {
3470   gold_assert(this->saw_sections_clause_);
3471
3472   // Implement ONLY_IF_RO/ONLY_IF_RW constraints.  These are a pain
3473   // for our representation.
3474   for (Sections_elements::iterator p = this->sections_elements_->begin();
3475        p != this->sections_elements_->end();
3476        ++p)
3477     {
3478       Output_section_definition* posd;
3479       Section_constraint failed_constraint = (*p)->check_constraint(&posd);
3480       if (failed_constraint != CONSTRAINT_NONE)
3481         {
3482           Sections_elements::iterator q;
3483           for (q = this->sections_elements_->begin();
3484                q != this->sections_elements_->end();
3485                ++q)
3486             {
3487               if (q != p)
3488                 {
3489                   if ((*q)->alternate_constraint(posd, failed_constraint))
3490                     break;
3491                 }
3492             }
3493
3494           if (q == this->sections_elements_->end())
3495             gold_error(_("no matching section constraint"));
3496         }
3497     }
3498
3499   // Force the alignment of the first TLS section to be the maximum
3500   // alignment of all TLS sections.
3501   Output_section* first_tls = NULL;
3502   uint64_t tls_align = 0;
3503   for (Sections_elements::const_iterator p = this->sections_elements_->begin();
3504        p != this->sections_elements_->end();
3505        ++p)
3506     {
3507       Output_section* os = (*p)->get_output_section();
3508       if (os != NULL && (os->flags() & elfcpp::SHF_TLS) != 0)
3509         {
3510           if (first_tls == NULL)
3511             first_tls = os;
3512           if (os->addralign() > tls_align)
3513             tls_align = os->addralign();
3514         }
3515     }
3516   if (first_tls != NULL)
3517     first_tls->set_addralign(tls_align);
3518
3519   // For a relocatable link, we implicitly set dot to zero.
3520   uint64_t dot_value = 0;
3521   uint64_t dot_alignment = 0;
3522   uint64_t load_address = 0;
3523
3524   // Check to see if we want to use any of -Ttext, -Tdata and -Tbss options
3525   // to set section addresses.  If the script has any SEGMENT_START
3526   // expression, we do not set the section addresses.
3527   bool use_tsection_options =
3528     (!this->saw_segment_start_expression_
3529      && (parameters->options().user_set_Ttext()
3530          || parameters->options().user_set_Tdata()
3531          || parameters->options().user_set_Tbss()));
3532
3533   for (Sections_elements::iterator p = this->sections_elements_->begin();
3534        p != this->sections_elements_->end();
3535        ++p)
3536     {
3537       Output_section* os = (*p)->get_output_section();
3538
3539       // Handle -Ttext, -Tdata and -Tbss options.  We do this by looking for
3540       // the special sections by names and doing dot assignments.
3541       if (use_tsection_options
3542           && os != NULL
3543           && (os->flags() & elfcpp::SHF_ALLOC) != 0)
3544         {
3545           uint64_t new_dot_value = dot_value;
3546
3547           if (parameters->options().user_set_Ttext()
3548               && strcmp(os->name(), ".text") == 0)
3549             new_dot_value = parameters->options().Ttext();
3550           else if (parameters->options().user_set_Tdata()
3551               && strcmp(os->name(), ".data") == 0)
3552             new_dot_value = parameters->options().Tdata();
3553           else if (parameters->options().user_set_Tbss()
3554               && strcmp(os->name(), ".bss") == 0)
3555             new_dot_value = parameters->options().Tbss();
3556
3557           // Update dot and load address if necessary.
3558           if (new_dot_value < dot_value)
3559             gold_error(_("dot may not move backward"));
3560           else if (new_dot_value != dot_value)
3561             {
3562               dot_value = new_dot_value;
3563               load_address = new_dot_value;
3564             }
3565         }
3566
3567       (*p)->set_section_addresses(symtab, layout, &dot_value, &dot_alignment,
3568                                   &load_address);
3569     }
3570
3571   if (this->phdrs_elements_ != NULL)
3572     {
3573       for (Phdrs_elements::iterator p = this->phdrs_elements_->begin();
3574            p != this->phdrs_elements_->end();
3575            ++p)
3576         (*p)->eval_load_address(symtab, layout);
3577     }
3578
3579   return this->create_segments(layout, dot_alignment);
3580 }
3581
3582 // Sort the sections in order to put them into segments.
3583
3584 class Sort_output_sections
3585 {
3586  public:
3587   Sort_output_sections(const Script_sections::Sections_elements* elements)
3588    : elements_(elements)
3589   { }
3590
3591   bool
3592   operator()(const Output_section* os1, const Output_section* os2) const;
3593
3594  private:
3595   int
3596   script_compare(const Output_section* os1, const Output_section* os2) const;
3597
3598  private:
3599   const Script_sections::Sections_elements* elements_;
3600 };
3601
3602 bool
3603 Sort_output_sections::operator()(const Output_section* os1,
3604                                  const Output_section* os2) const
3605 {
3606   // Sort first by the load address.
3607   uint64_t lma1 = (os1->has_load_address()
3608                    ? os1->load_address()
3609                    : os1->address());
3610   uint64_t lma2 = (os2->has_load_address()
3611                    ? os2->load_address()
3612                    : os2->address());
3613   if (lma1 != lma2)
3614     return lma1 < lma2;
3615
3616   // Then sort by the virtual address.
3617   if (os1->address() != os2->address())
3618     return os1->address() < os2->address();
3619
3620   // If the linker script says which of these sections is first, go
3621   // with what it says.
3622   int i = this->script_compare(os1, os2);
3623   if (i != 0)
3624     return i < 0;
3625
3626   // Sort PROGBITS before NOBITS.
3627   bool nobits1 = os1->type() == elfcpp::SHT_NOBITS;
3628   bool nobits2 = os2->type() == elfcpp::SHT_NOBITS;
3629   if (nobits1 != nobits2)
3630     return nobits2;
3631
3632   // Sort PROGBITS TLS sections to the end, NOBITS TLS sections to the
3633   // beginning.
3634   bool tls1 = (os1->flags() & elfcpp::SHF_TLS) != 0;
3635   bool tls2 = (os2->flags() & elfcpp::SHF_TLS) != 0;
3636   if (tls1 != tls2)
3637     return nobits1 ? tls1 : tls2;
3638
3639   // Sort non-NOLOAD before NOLOAD.
3640   if (os1->is_noload() && !os2->is_noload())
3641     return true;
3642   if (!os1->is_noload() && os2->is_noload())
3643     return true;
3644
3645   // The sections seem practically identical.  Sort by name to get a
3646   // stable sort.
3647   return os1->name() < os2->name();
3648 }
3649
3650 // Return -1 if OS1 comes before OS2 in ELEMENTS_, 1 if comes after, 0
3651 // if either OS1 or OS2 is not mentioned.  This ensures that we keep
3652 // empty sections in the order in which they appear in a linker
3653 // script.
3654
3655 int
3656 Sort_output_sections::script_compare(const Output_section* os1,
3657                                      const Output_section* os2) const
3658 {
3659   if (this->elements_ == NULL)
3660     return 0;
3661
3662   bool found_os1 = false;
3663   bool found_os2 = false;
3664   for (Script_sections::Sections_elements::const_iterator
3665          p = this->elements_->begin();
3666        p != this->elements_->end();
3667        ++p)
3668     {
3669       if (os2 == (*p)->get_output_section())
3670         {
3671           if (found_os1)
3672             return -1;
3673           found_os2 = true;
3674         }
3675       else if (os1 == (*p)->get_output_section())
3676         {
3677           if (found_os2)
3678             return 1;
3679           found_os1 = true;
3680         }
3681     }
3682
3683   return 0;
3684 }
3685
3686 // Return whether OS is a BSS section.  This is a SHT_NOBITS section.
3687 // We treat a section with the SHF_TLS flag set as taking up space
3688 // even if it is SHT_NOBITS (this is true of .tbss), as we allocate
3689 // space for them in the file.
3690
3691 bool
3692 Script_sections::is_bss_section(const Output_section* os)
3693 {
3694   return (os->type() == elfcpp::SHT_NOBITS
3695           && (os->flags() & elfcpp::SHF_TLS) == 0);
3696 }
3697
3698 // Return the size taken by the file header and the program headers.
3699
3700 size_t
3701 Script_sections::total_header_size(Layout* layout) const
3702 {
3703   size_t segment_count = layout->segment_count();
3704   size_t file_header_size;
3705   size_t segment_headers_size;
3706   if (parameters->target().get_size() == 32)
3707     {
3708       file_header_size = elfcpp::Elf_sizes<32>::ehdr_size;
3709       segment_headers_size = segment_count * elfcpp::Elf_sizes<32>::phdr_size;
3710     }
3711   else if (parameters->target().get_size() == 64)
3712     {
3713       file_header_size = elfcpp::Elf_sizes<64>::ehdr_size;
3714       segment_headers_size = segment_count * elfcpp::Elf_sizes<64>::phdr_size;
3715     }
3716   else
3717     gold_unreachable();
3718
3719   return file_header_size + segment_headers_size;
3720 }
3721
3722 // Return the amount we have to subtract from the LMA to accommodate
3723 // headers of the given size.  The complication is that the file
3724 // header have to be at the start of a page, as otherwise it will not
3725 // be at the start of the file.
3726
3727 uint64_t
3728 Script_sections::header_size_adjustment(uint64_t lma,
3729                                         size_t sizeof_headers) const
3730 {
3731   const uint64_t abi_pagesize = parameters->target().abi_pagesize();
3732   uint64_t hdr_lma = lma - sizeof_headers;
3733   hdr_lma &= ~(abi_pagesize - 1);
3734   return lma - hdr_lma;
3735 }
3736
3737 // Create the PT_LOAD segments when using a SECTIONS clause.  Returns
3738 // the segment which should hold the file header and segment headers,
3739 // if any.
3740
3741 Output_segment*
3742 Script_sections::create_segments(Layout* layout, uint64_t dot_alignment)
3743 {
3744   gold_assert(this->saw_sections_clause_);
3745
3746   if (parameters->options().relocatable())
3747     return NULL;
3748
3749   if (this->saw_phdrs_clause())
3750     return create_segments_from_phdrs_clause(layout, dot_alignment);
3751
3752   Layout::Section_list sections;
3753   layout->get_allocated_sections(&sections);
3754
3755   // Sort the sections by address.
3756   std::stable_sort(sections.begin(), sections.end(),
3757                    Sort_output_sections(this->sections_elements_));
3758
3759   this->create_note_and_tls_segments(layout, &sections);
3760
3761   // Walk through the sections adding them to PT_LOAD segments.
3762   const uint64_t abi_pagesize = parameters->target().abi_pagesize();
3763   Output_segment* first_seg = NULL;
3764   Output_segment* current_seg = NULL;
3765   bool is_current_seg_readonly = true;
3766   Layout::Section_list::iterator plast = sections.end();
3767   uint64_t last_vma = 0;
3768   uint64_t last_lma = 0;
3769   uint64_t last_size = 0;
3770   for (Layout::Section_list::iterator p = sections.begin();
3771        p != sections.end();
3772        ++p)
3773     {
3774       const uint64_t vma = (*p)->address();
3775       const uint64_t lma = ((*p)->has_load_address()
3776                             ? (*p)->load_address()
3777                             : vma);
3778       const uint64_t size = (*p)->current_data_size();
3779
3780       bool need_new_segment;
3781       if (current_seg == NULL)
3782         need_new_segment = true;
3783       else if (lma - vma != last_lma - last_vma)
3784         {
3785           // This section has a different LMA relationship than the
3786           // last one; we need a new segment.
3787           need_new_segment = true;
3788         }
3789       else if (align_address(last_lma + last_size, abi_pagesize)
3790                < align_address(lma, abi_pagesize))
3791         {
3792           // Putting this section in the segment would require
3793           // skipping a page.
3794           need_new_segment = true;
3795         }
3796       else if (is_bss_section(*plast) && !is_bss_section(*p))
3797         {
3798           // A non-BSS section can not follow a BSS section in the
3799           // same segment.
3800           need_new_segment = true;
3801         }
3802       else if (is_current_seg_readonly
3803                && ((*p)->flags() & elfcpp::SHF_WRITE) != 0
3804                && !parameters->options().omagic())
3805         {
3806           // Don't put a writable section in the same segment as a
3807           // non-writable section.
3808           need_new_segment = true;
3809         }
3810       else
3811         {
3812           // Otherwise, reuse the existing segment.
3813           need_new_segment = false;
3814         }
3815
3816       elfcpp::Elf_Word seg_flags =
3817         Layout::section_flags_to_segment((*p)->flags());
3818
3819       if (need_new_segment)
3820         {
3821           current_seg = layout->make_output_segment(elfcpp::PT_LOAD,
3822                                                     seg_flags);
3823           current_seg->set_addresses(vma, lma);
3824           current_seg->set_minimum_p_align(dot_alignment);
3825           if (first_seg == NULL)
3826             first_seg = current_seg;
3827           is_current_seg_readonly = true;
3828         }
3829
3830       current_seg->add_output_section_to_load(layout, *p, seg_flags);
3831
3832       if (((*p)->flags() & elfcpp::SHF_WRITE) != 0)
3833         is_current_seg_readonly = false;
3834
3835       plast = p;
3836       last_vma = vma;
3837       last_lma = lma;
3838       last_size = size;
3839     }
3840
3841   // An ELF program should work even if the program headers are not in
3842   // a PT_LOAD segment.  However, it appears that the Linux kernel
3843   // does not set the AT_PHDR auxiliary entry in that case.  It sets
3844   // the load address to p_vaddr - p_offset of the first PT_LOAD
3845   // segment.  It then sets AT_PHDR to the load address plus the
3846   // offset to the program headers, e_phoff in the file header.  This
3847   // fails when the program headers appear in the file before the
3848   // first PT_LOAD segment.  Therefore, we always create a PT_LOAD
3849   // segment to hold the file header and the program headers.  This is
3850   // effectively what the GNU linker does, and it is slightly more
3851   // efficient in any case.  We try to use the first PT_LOAD segment
3852   // if we can, otherwise we make a new one.
3853
3854   if (first_seg == NULL)
3855     return NULL;
3856
3857   // -n or -N mean that the program is not demand paged and there is
3858   // no need to put the program headers in a PT_LOAD segment.
3859   if (parameters->options().nmagic() || parameters->options().omagic())
3860     return NULL;
3861
3862   size_t sizeof_headers = this->total_header_size(layout);
3863
3864   uint64_t vma = first_seg->vaddr();
3865   uint64_t lma = first_seg->paddr();
3866
3867   uint64_t subtract = this->header_size_adjustment(lma, sizeof_headers);
3868
3869   if ((lma & (abi_pagesize - 1)) >= sizeof_headers)
3870     {
3871       first_seg->set_addresses(vma - subtract, lma - subtract);
3872       return first_seg;
3873     }
3874
3875   // If there is no room to squeeze in the headers, then punt.  The
3876   // resulting executable probably won't run on GNU/Linux, but we
3877   // trust that the user knows what they are doing.
3878   if (lma < subtract || vma < subtract)
3879     return NULL;
3880
3881   // If memory regions have been specified and the address range
3882   // we are about to use is not contained within any region then
3883   // issue a warning message about the segment we are going to
3884   // create.  It will be outside of any region and so possibly
3885   // using non-existent or protected memory.  We test LMA rather
3886   // than VMA since we assume that the headers will never be
3887   // relocated.
3888   if (this->memory_regions_ != NULL
3889       && !this->block_in_region (NULL, layout, lma - subtract, subtract))
3890     gold_warning(_("creating a segment to contain the file and program"
3891                    " headers outside of any MEMORY region"));
3892
3893   Output_segment* load_seg = layout->make_output_segment(elfcpp::PT_LOAD,
3894                                                          elfcpp::PF_R);
3895   load_seg->set_addresses(vma - subtract, lma - subtract);
3896
3897   return load_seg;
3898 }
3899
3900 // Create a PT_NOTE segment for each SHT_NOTE section and a PT_TLS
3901 // segment if there are any SHT_TLS sections.
3902
3903 void
3904 Script_sections::create_note_and_tls_segments(
3905     Layout* layout,
3906     const Layout::Section_list* sections)
3907 {
3908   gold_assert(!this->saw_phdrs_clause());
3909
3910   bool saw_tls = false;
3911   for (Layout::Section_list::const_iterator p = sections->begin();
3912        p != sections->end();
3913        ++p)
3914     {
3915       if ((*p)->type() == elfcpp::SHT_NOTE)
3916         {
3917           elfcpp::Elf_Word seg_flags =
3918             Layout::section_flags_to_segment((*p)->flags());
3919           Output_segment* oseg = layout->make_output_segment(elfcpp::PT_NOTE,
3920                                                              seg_flags);
3921           oseg->add_output_section_to_nonload(*p, seg_flags);
3922
3923           // Incorporate any subsequent SHT_NOTE sections, in the
3924           // hopes that the script is sensible.
3925           Layout::Section_list::const_iterator pnext = p + 1;
3926           while (pnext != sections->end()
3927                  && (*pnext)->type() == elfcpp::SHT_NOTE)
3928             {
3929               seg_flags = Layout::section_flags_to_segment((*pnext)->flags());
3930               oseg->add_output_section_to_nonload(*pnext, seg_flags);
3931               p = pnext;
3932               ++pnext;
3933             }
3934         }
3935
3936       if (((*p)->flags() & elfcpp::SHF_TLS) != 0)
3937         {
3938           if (saw_tls)
3939             gold_error(_("TLS sections are not adjacent"));
3940
3941           elfcpp::Elf_Word seg_flags =
3942             Layout::section_flags_to_segment((*p)->flags());
3943           Output_segment* oseg = layout->make_output_segment(elfcpp::PT_TLS,
3944                                                              seg_flags);
3945           oseg->add_output_section_to_nonload(*p, seg_flags);
3946
3947           Layout::Section_list::const_iterator pnext = p + 1;
3948           while (pnext != sections->end()
3949                  && ((*pnext)->flags() & elfcpp::SHF_TLS) != 0)
3950             {
3951               seg_flags = Layout::section_flags_to_segment((*pnext)->flags());
3952               oseg->add_output_section_to_nonload(*pnext, seg_flags);
3953               p = pnext;
3954               ++pnext;
3955             }
3956
3957           saw_tls = true;
3958         }
3959
3960       // If we are making a shared library, and we see a section named
3961       // .interp then put the .interp section in a PT_INTERP segment.
3962       // This is for GNU ld compatibility.
3963       if (strcmp((*p)->name(), ".interp") == 0)
3964         {
3965           elfcpp::Elf_Word seg_flags =
3966             Layout::section_flags_to_segment((*p)->flags());
3967           Output_segment* oseg = layout->make_output_segment(elfcpp::PT_INTERP,
3968                                                              seg_flags);
3969           oseg->add_output_section_to_nonload(*p, seg_flags);
3970         }
3971     }
3972 }
3973
3974 // Add a program header.  The PHDRS clause is syntactically distinct
3975 // from the SECTIONS clause, but we implement it with the SECTIONS
3976 // support because PHDRS is useless if there is no SECTIONS clause.
3977
3978 void
3979 Script_sections::add_phdr(const char* name, size_t namelen, unsigned int type,
3980                           bool includes_filehdr, bool includes_phdrs,
3981                           bool is_flags_valid, unsigned int flags,
3982                           Expression* load_address)
3983 {
3984   if (this->phdrs_elements_ == NULL)
3985     this->phdrs_elements_ = new Phdrs_elements();
3986   this->phdrs_elements_->push_back(new Phdrs_element(name, namelen, type,
3987                                                      includes_filehdr,
3988                                                      includes_phdrs,
3989                                                      is_flags_valid, flags,
3990                                                      load_address));
3991 }
3992
3993 // Return the number of segments we expect to create based on the
3994 // SECTIONS clause.  This is used to implement SIZEOF_HEADERS.
3995
3996 size_t
3997 Script_sections::expected_segment_count(const Layout* layout) const
3998 {
3999   if (this->saw_phdrs_clause())
4000     return this->phdrs_elements_->size();
4001
4002   Layout::Section_list sections;
4003   layout->get_allocated_sections(&sections);
4004
4005   // We assume that we will need two PT_LOAD segments.
4006   size_t ret = 2;
4007
4008   bool saw_note = false;
4009   bool saw_tls = false;
4010   for (Layout::Section_list::const_iterator p = sections.begin();
4011        p != sections.end();
4012        ++p)
4013     {
4014       if ((*p)->type() == elfcpp::SHT_NOTE)
4015         {
4016           // Assume that all note sections will fit into a single
4017           // PT_NOTE segment.
4018           if (!saw_note)
4019             {
4020               ++ret;
4021               saw_note = true;
4022             }
4023         }
4024       else if (((*p)->flags() & elfcpp::SHF_TLS) != 0)
4025         {
4026           // There can only be one PT_TLS segment.
4027           if (!saw_tls)
4028             {
4029               ++ret;
4030               saw_tls = true;
4031             }
4032         }
4033     }
4034
4035   return ret;
4036 }
4037
4038 // Create the segments from a PHDRS clause.  Return the segment which
4039 // should hold the file header and program headers, if any.
4040
4041 Output_segment*
4042 Script_sections::create_segments_from_phdrs_clause(Layout* layout,
4043                                                    uint64_t dot_alignment)
4044 {
4045   this->attach_sections_using_phdrs_clause(layout);
4046   return this->set_phdrs_clause_addresses(layout, dot_alignment);
4047 }
4048
4049 // Create the segments from the PHDRS clause, and put the output
4050 // sections in them.
4051
4052 void
4053 Script_sections::attach_sections_using_phdrs_clause(Layout* layout)
4054 {
4055   typedef std::map<std::string, Output_segment*> Name_to_segment;
4056   Name_to_segment name_to_segment;
4057   for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4058        p != this->phdrs_elements_->end();
4059        ++p)
4060     name_to_segment[(*p)->name()] = (*p)->create_segment(layout);
4061
4062   // Walk through the output sections and attach them to segments.
4063   // Output sections in the script which do not list segments are
4064   // attached to the same set of segments as the immediately preceding
4065   // output section.
4066
4067   String_list* phdr_names = NULL;
4068   bool load_segments_only = false;
4069   for (Sections_elements::const_iterator p = this->sections_elements_->begin();
4070        p != this->sections_elements_->end();
4071        ++p)
4072     {
4073       bool is_orphan;
4074       String_list* old_phdr_names = phdr_names;
4075       Output_section* os = (*p)->allocate_to_segment(&phdr_names, &is_orphan);
4076       if (os == NULL)
4077         continue;
4078
4079       elfcpp::Elf_Word seg_flags =
4080         Layout::section_flags_to_segment(os->flags());
4081
4082       if (phdr_names == NULL)
4083         {
4084           // Don't worry about empty orphan sections.
4085           if (is_orphan && os->current_data_size() > 0)
4086             gold_error(_("allocated section %s not in any segment"),
4087                        os->name());
4088
4089           // To avoid later crashes drop this section into the first
4090           // PT_LOAD segment.
4091           for (Phdrs_elements::const_iterator ppe =
4092                  this->phdrs_elements_->begin();
4093                ppe != this->phdrs_elements_->end();
4094                ++ppe)
4095             {
4096               Output_segment* oseg = (*ppe)->segment();
4097               if (oseg->type() == elfcpp::PT_LOAD)
4098                 {
4099                   oseg->add_output_section_to_load(layout, os, seg_flags);
4100                   break;
4101                 }
4102             }
4103
4104           continue;
4105         }
4106
4107       // We see a list of segments names.  Disable PT_LOAD segment only
4108       // filtering.
4109       if (old_phdr_names != phdr_names)
4110         load_segments_only = false;
4111
4112       // If this is an orphan section--one that was not explicitly
4113       // mentioned in the linker script--then it should not inherit
4114       // any segment type other than PT_LOAD.  Otherwise, e.g., the
4115       // PT_INTERP segment will pick up following orphan sections,
4116       // which does not make sense.  If this is not an orphan section,
4117       // we trust the linker script.
4118       if (is_orphan)
4119         {
4120           // Enable PT_LOAD segments only filtering until we see another
4121           // list of segment names.
4122           load_segments_only = true;
4123         }
4124
4125       bool in_load_segment = false;
4126       for (String_list::const_iterator q = phdr_names->begin();
4127            q != phdr_names->end();
4128            ++q)
4129         {
4130           Name_to_segment::const_iterator r = name_to_segment.find(*q);
4131           if (r == name_to_segment.end())
4132             gold_error(_("no segment %s"), q->c_str());
4133           else
4134             {
4135               if (load_segments_only
4136                   && r->second->type() != elfcpp::PT_LOAD)
4137                 continue;
4138
4139               if (r->second->type() != elfcpp::PT_LOAD)
4140                 r->second->add_output_section_to_nonload(os, seg_flags);
4141               else
4142                 {
4143                   r->second->add_output_section_to_load(layout, os, seg_flags);
4144                   if (in_load_segment)
4145                     gold_error(_("section in two PT_LOAD segments"));
4146                   in_load_segment = true;
4147                 }
4148             }
4149         }
4150
4151       if (!in_load_segment)
4152         gold_error(_("allocated section not in any PT_LOAD segment"));
4153     }
4154 }
4155
4156 // Set the addresses for segments created from a PHDRS clause.  Return
4157 // the segment which should hold the file header and program headers,
4158 // if any.
4159
4160 Output_segment*
4161 Script_sections::set_phdrs_clause_addresses(Layout* layout,
4162                                             uint64_t dot_alignment)
4163 {
4164   Output_segment* load_seg = NULL;
4165   for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4166        p != this->phdrs_elements_->end();
4167        ++p)
4168     {
4169       // Note that we have to set the flags after adding the output
4170       // sections to the segment, as adding an output segment can
4171       // change the flags.
4172       (*p)->set_flags_if_valid();
4173
4174       Output_segment* oseg = (*p)->segment();
4175
4176       if (oseg->type() != elfcpp::PT_LOAD)
4177         {
4178           // The addresses of non-PT_LOAD segments are set from the
4179           // PT_LOAD segments.
4180           if ((*p)->has_load_address())
4181             gold_error(_("may only specify load address for PT_LOAD segment"));
4182           continue;
4183         }
4184
4185       oseg->set_minimum_p_align(dot_alignment);
4186
4187       // The output sections should have addresses from the SECTIONS
4188       // clause.  The addresses don't have to be in order, so find the
4189       // one with the lowest load address.  Use that to set the
4190       // address of the segment.
4191
4192       Output_section* osec = oseg->section_with_lowest_load_address();
4193       if (osec == NULL)
4194         {
4195           oseg->set_addresses(0, 0);
4196           continue;
4197         }
4198
4199       uint64_t vma = osec->address();
4200       uint64_t lma = osec->has_load_address() ? osec->load_address() : vma;
4201
4202       // Override the load address of the section with the load
4203       // address specified for the segment.
4204       if ((*p)->has_load_address())
4205         {
4206           if (osec->has_load_address())
4207             gold_warning(_("PHDRS load address overrides "
4208                            "section %s load address"),
4209                          osec->name());
4210
4211           lma = (*p)->load_address();
4212         }
4213
4214       bool headers = (*p)->includes_filehdr() && (*p)->includes_phdrs();
4215       if (!headers && ((*p)->includes_filehdr() || (*p)->includes_phdrs()))
4216         {
4217           // We could support this if we wanted to.
4218           gold_error(_("using only one of FILEHDR and PHDRS is "
4219                        "not currently supported"));
4220         }
4221       if (headers)
4222         {
4223           size_t sizeof_headers = this->total_header_size(layout);
4224           uint64_t subtract = this->header_size_adjustment(lma,
4225                                                            sizeof_headers);
4226           if (lma >= subtract && vma >= subtract)
4227             {
4228               lma -= subtract;
4229               vma -= subtract;
4230             }
4231           else
4232             {
4233               gold_error(_("sections loaded on first page without room "
4234                            "for file and program headers "
4235                            "are not supported"));
4236             }
4237
4238           if (load_seg != NULL)
4239             gold_error(_("using FILEHDR and PHDRS on more than one "
4240                          "PT_LOAD segment is not currently supported"));
4241           load_seg = oseg;
4242         }
4243
4244       oseg->set_addresses(vma, lma);
4245     }
4246
4247   return load_seg;
4248 }
4249
4250 // Add the file header and segment headers to non-load segments
4251 // specified in the PHDRS clause.
4252
4253 void
4254 Script_sections::put_headers_in_phdrs(Output_data* file_header,
4255                                       Output_data* segment_headers)
4256 {
4257   gold_assert(this->saw_phdrs_clause());
4258   for (Phdrs_elements::iterator p = this->phdrs_elements_->begin();
4259        p != this->phdrs_elements_->end();
4260        ++p)
4261     {
4262       if ((*p)->type() != elfcpp::PT_LOAD)
4263         {
4264           if ((*p)->includes_phdrs())
4265             (*p)->segment()->add_initial_output_data(segment_headers);
4266           if ((*p)->includes_filehdr())
4267             (*p)->segment()->add_initial_output_data(file_header);
4268         }
4269     }
4270 }
4271
4272 // Look for an output section by name and return the address, the load
4273 // address, the alignment, and the size.  This is used when an
4274 // expression refers to an output section which was not actually
4275 // created.  This returns true if the section was found, false
4276 // otherwise.
4277
4278 bool
4279 Script_sections::get_output_section_info(const char* name, uint64_t* address,
4280                                          uint64_t* load_address,
4281                                          uint64_t* addralign,
4282                                          uint64_t* size) const
4283 {
4284   if (!this->saw_sections_clause_)
4285     return false;
4286   for (Sections_elements::const_iterator p = this->sections_elements_->begin();
4287        p != this->sections_elements_->end();
4288        ++p)
4289     if ((*p)->get_output_section_info(name, address, load_address, addralign,
4290                                       size))
4291       return true;
4292   return false;
4293 }
4294
4295 // Release all Output_segments.  This remove all pointers to all
4296 // Output_segments.
4297
4298 void
4299 Script_sections::release_segments()
4300 {
4301   if (this->saw_phdrs_clause())
4302     {
4303       for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4304            p != this->phdrs_elements_->end();
4305            ++p)
4306         (*p)->release_segment();
4307     }
4308 }
4309
4310 // Print the SECTIONS clause to F for debugging.
4311
4312 void
4313 Script_sections::print(FILE* f) const
4314 {
4315   if (this->phdrs_elements_ != NULL)
4316     {
4317       fprintf(f, "PHDRS {\n");
4318       for (Phdrs_elements::const_iterator p = this->phdrs_elements_->begin();
4319            p != this->phdrs_elements_->end();
4320            ++p)
4321         (*p)->print(f);
4322       fprintf(f, "}\n");
4323     }
4324
4325   if (this->memory_regions_ != NULL)
4326     {
4327       fprintf(f, "MEMORY {\n");
4328       for (Memory_regions::const_iterator m = this->memory_regions_->begin();
4329            m != this->memory_regions_->end();
4330            ++m)
4331         (*m)->print(f);
4332       fprintf(f, "}\n");
4333     }
4334
4335   if (!this->saw_sections_clause_)
4336     return;
4337
4338   fprintf(f, "SECTIONS {\n");
4339
4340   for (Sections_elements::const_iterator p = this->sections_elements_->begin();
4341        p != this->sections_elements_->end();
4342        ++p)
4343     (*p)->print(f);
4344
4345   fprintf(f, "}\n");
4346 }
4347
4348 } // End namespace gold.