DLL.cpp 23.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744
//===- DLL.cpp ------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines various types of chunks for the DLL import or export
// descriptor tables. They are inherently Windows-specific.
// You need to read Microsoft PE/COFF spec to understand details
// about the data structures.
//
// If you are not particularly interested in linking against Windows
// DLL, you can skip this file, and you should still be able to
// understand the rest of the linker.
//
//===----------------------------------------------------------------------===//

#include "DLL.h"
#include "Chunks.h"
#include "llvm/Object/COFF.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/Path.h"

using namespace llvm;
using namespace llvm::object;
using namespace llvm::support::endian;
using namespace llvm::COFF;

namespace lld {
namespace coff {
namespace {

// Import table

// A chunk for the import descriptor table.
class HintNameChunk : public NonSectionChunk {
public:
  HintNameChunk(StringRef n, uint16_t h) : name(n), hint(h) {}

  size_t getSize() const override {
    // Starts with 2 byte Hint field, followed by a null-terminated string,
    // ends with 0 or 1 byte padding.
    return alignTo(name.size() + 3, 2);
  }

  void writeTo(uint8_t *buf) const override {
    memset(buf, 0, getSize());
    write16le(buf, hint);
    memcpy(buf + 2, name.data(), name.size());
  }

private:
  StringRef name;
  uint16_t hint;
};

// A chunk for the import descriptor table.
class LookupChunk : public NonSectionChunk {
public:
  explicit LookupChunk(Chunk *c) : hintName(c) {
    setAlignment(config->wordsize);
  }
  size_t getSize() const override { return config->wordsize; }

  void writeTo(uint8_t *buf) const override {
    if (config->is64())
      write64le(buf, hintName->getRVA());
    else
      write32le(buf, hintName->getRVA());
  }

  Chunk *hintName;
};

// A chunk for the import descriptor table.
// This chunk represent import-by-ordinal symbols.
// See Microsoft PE/COFF spec 7.1. Import Header for details.
class OrdinalOnlyChunk : public NonSectionChunk {
public:
  explicit OrdinalOnlyChunk(uint16_t v) : ordinal(v) {
    setAlignment(config->wordsize);
  }
  size_t getSize() const override { return config->wordsize; }

  void writeTo(uint8_t *buf) const override {
    // An import-by-ordinal slot has MSB 1 to indicate that
    // this is import-by-ordinal (and not import-by-name).
    if (config->is64()) {
      write64le(buf, (1ULL << 63) | ordinal);
    } else {
      write32le(buf, (1ULL << 31) | ordinal);
    }
  }

  uint16_t ordinal;
};

// A chunk for the import descriptor table.
class ImportDirectoryChunk : public NonSectionChunk {
public:
  explicit ImportDirectoryChunk(Chunk *n) : dllName(n) {}
  size_t getSize() const override { return sizeof(ImportDirectoryTableEntry); }

  void writeTo(uint8_t *buf) const override {
    memset(buf, 0, getSize());

    auto *e = (coff_import_directory_table_entry *)(buf);
    e->ImportLookupTableRVA = lookupTab->getRVA();
    e->NameRVA = dllName->getRVA();
    e->ImportAddressTableRVA = addressTab->getRVA();
  }

  Chunk *dllName;
  Chunk *lookupTab;
  Chunk *addressTab;
};

// A chunk representing null terminator in the import table.
// Contents of this chunk is always null bytes.
class NullChunk : public NonSectionChunk {
public:
  explicit NullChunk(size_t n) : size(n) { hasData = false; }
  size_t getSize() const override { return size; }

  void writeTo(uint8_t *buf) const override {
    memset(buf, 0, size);
  }

private:
  size_t size;
};

static std::vector<std::vector<DefinedImportData *>>
binImports(const std::vector<DefinedImportData *> &imports) {
  // Group DLL-imported symbols by DLL name because that's how
  // symbols are laid out in the import descriptor table.
  auto less = [](const std::string &a, const std::string &b) {
    return config->dllOrder[a] < config->dllOrder[b];
  };
  std::map<std::string, std::vector<DefinedImportData *>,
           bool(*)(const std::string &, const std::string &)> m(less);
  for (DefinedImportData *sym : imports)
    m[sym->getDLLName().lower()].push_back(sym);

  std::vector<std::vector<DefinedImportData *>> v;
  for (auto &kv : m) {
    // Sort symbols by name for each group.
    std::vector<DefinedImportData *> &syms = kv.second;
    std::sort(syms.begin(), syms.end(),
              [](DefinedImportData *a, DefinedImportData *b) {
                return a->getName() < b->getName();
              });
    v.push_back(std::move(syms));
  }
  return v;
}

// Export table
// See Microsoft PE/COFF spec 4.3 for details.

// A chunk for the delay import descriptor table etnry.
class DelayDirectoryChunk : public NonSectionChunk {
public:
  explicit DelayDirectoryChunk(Chunk *n) : dllName(n) {}

  size_t getSize() const override {
    return sizeof(delay_import_directory_table_entry);
  }

  void writeTo(uint8_t *buf) const override {
    memset(buf, 0, getSize());

    auto *e = (delay_import_directory_table_entry *)(buf);
    e->Attributes = 1;
    e->Name = dllName->getRVA();
    e->ModuleHandle = moduleHandle->getRVA();
    e->DelayImportAddressTable = addressTab->getRVA();
    e->DelayImportNameTable = nameTab->getRVA();
  }

  Chunk *dllName;
  Chunk *moduleHandle;
  Chunk *addressTab;
  Chunk *nameTab;
};

// Initial contents for delay-loaded functions.
// This code calls __delayLoadHelper2 function to resolve a symbol
// which then overwrites its jump table slot with the result
// for subsequent function calls.
static const uint8_t thunkX64[] = {
    0x48, 0x8D, 0x05, 0, 0, 0, 0,       // lea     rax, [__imp_<FUNCNAME>]
    0xE9, 0, 0, 0, 0,                   // jmp     __tailMerge_<lib>
};

static const uint8_t tailMergeX64[] = {
    0x51,                               // push    rcx
    0x52,                               // push    rdx
    0x41, 0x50,                         // push    r8
    0x41, 0x51,                         // push    r9
    0x48, 0x83, 0xEC, 0x48,             // sub     rsp, 48h
    0x66, 0x0F, 0x7F, 0x04, 0x24,       // movdqa  xmmword ptr [rsp], xmm0
    0x66, 0x0F, 0x7F, 0x4C, 0x24, 0x10, // movdqa  xmmword ptr [rsp+10h], xmm1
    0x66, 0x0F, 0x7F, 0x54, 0x24, 0x20, // movdqa  xmmword ptr [rsp+20h], xmm2
    0x66, 0x0F, 0x7F, 0x5C, 0x24, 0x30, // movdqa  xmmword ptr [rsp+30h], xmm3
    0x48, 0x8B, 0xD0,                   // mov     rdx, rax
    0x48, 0x8D, 0x0D, 0, 0, 0, 0,       // lea     rcx, [___DELAY_IMPORT_...]
    0xE8, 0, 0, 0, 0,                   // call    __delayLoadHelper2
    0x66, 0x0F, 0x6F, 0x04, 0x24,       // movdqa  xmm0, xmmword ptr [rsp]
    0x66, 0x0F, 0x6F, 0x4C, 0x24, 0x10, // movdqa  xmm1, xmmword ptr [rsp+10h]
    0x66, 0x0F, 0x6F, 0x54, 0x24, 0x20, // movdqa  xmm2, xmmword ptr [rsp+20h]
    0x66, 0x0F, 0x6F, 0x5C, 0x24, 0x30, // movdqa  xmm3, xmmword ptr [rsp+30h]
    0x48, 0x83, 0xC4, 0x48,             // add     rsp, 48h
    0x41, 0x59,                         // pop     r9
    0x41, 0x58,                         // pop     r8
    0x5A,                               // pop     rdx
    0x59,                               // pop     rcx
    0xFF, 0xE0,                         // jmp     rax
};

static const uint8_t thunkX86[] = {
    0xB8, 0, 0, 0, 0,  // mov   eax, offset ___imp__<FUNCNAME>
    0xE9, 0, 0, 0, 0,  // jmp   __tailMerge_<lib>
};

static const uint8_t tailMergeX86[] = {
    0x51,              // push  ecx
    0x52,              // push  edx
    0x50,              // push  eax
    0x68, 0, 0, 0, 0,  // push  offset ___DELAY_IMPORT_DESCRIPTOR_<DLLNAME>_dll
    0xE8, 0, 0, 0, 0,  // call  ___delayLoadHelper2@8
    0x5A,              // pop   edx
    0x59,              // pop   ecx
    0xFF, 0xE0,        // jmp   eax
};

static const uint8_t thunkARM[] = {
    0x40, 0xf2, 0x00, 0x0c, // mov.w   ip, #0 __imp_<FUNCNAME>
    0xc0, 0xf2, 0x00, 0x0c, // mov.t   ip, #0 __imp_<FUNCNAME>
    0x00, 0xf0, 0x00, 0xb8, // b.w     __tailMerge_<lib>
};

static const uint8_t tailMergeARM[] = {
    0x2d, 0xe9, 0x0f, 0x48, // push.w  {r0, r1, r2, r3, r11, lr}
    0x0d, 0xf2, 0x10, 0x0b, // addw    r11, sp, #16
    0x2d, 0xed, 0x10, 0x0b, // vpush   {d0, d1, d2, d3, d4, d5, d6, d7}
    0x61, 0x46,             // mov     r1, ip
    0x40, 0xf2, 0x00, 0x00, // mov.w   r0, #0 DELAY_IMPORT_DESCRIPTOR
    0xc0, 0xf2, 0x00, 0x00, // mov.t   r0, #0 DELAY_IMPORT_DESCRIPTOR
    0x00, 0xf0, 0x00, 0xd0, // bl      #0 __delayLoadHelper2
    0x84, 0x46,             // mov     ip, r0
    0xbd, 0xec, 0x10, 0x0b, // vpop    {d0, d1, d2, d3, d4, d5, d6, d7}
    0xbd, 0xe8, 0x0f, 0x48, // pop.w   {r0, r1, r2, r3, r11, lr}
    0x60, 0x47,             // bx      ip
};

static const uint8_t thunkARM64[] = {
    0x11, 0x00, 0x00, 0x90, // adrp    x17, #0      __imp_<FUNCNAME>
    0x31, 0x02, 0x00, 0x91, // add     x17, x17, #0 :lo12:__imp_<FUNCNAME>
    0x00, 0x00, 0x00, 0x14, // b       __tailMerge_<lib>
};

static const uint8_t tailMergeARM64[] = {
    0xfd, 0x7b, 0xb3, 0xa9, // stp     x29, x30, [sp, #-208]!
    0xfd, 0x03, 0x00, 0x91, // mov     x29, sp
    0xe0, 0x07, 0x01, 0xa9, // stp     x0, x1, [sp, #16]
    0xe2, 0x0f, 0x02, 0xa9, // stp     x2, x3, [sp, #32]
    0xe4, 0x17, 0x03, 0xa9, // stp     x4, x5, [sp, #48]
    0xe6, 0x1f, 0x04, 0xa9, // stp     x6, x7, [sp, #64]
    0xe0, 0x87, 0x02, 0xad, // stp     q0, q1, [sp, #80]
    0xe2, 0x8f, 0x03, 0xad, // stp     q2, q3, [sp, #112]
    0xe4, 0x97, 0x04, 0xad, // stp     q4, q5, [sp, #144]
    0xe6, 0x9f, 0x05, 0xad, // stp     q6, q7, [sp, #176]
    0xe1, 0x03, 0x11, 0xaa, // mov     x1, x17
    0x00, 0x00, 0x00, 0x90, // adrp    x0, #0     DELAY_IMPORT_DESCRIPTOR
    0x00, 0x00, 0x00, 0x91, // add     x0, x0, #0 :lo12:DELAY_IMPORT_DESCRIPTOR
    0x00, 0x00, 0x00, 0x94, // bl      #0 __delayLoadHelper2
    0xf0, 0x03, 0x00, 0xaa, // mov     x16, x0
    0xe6, 0x9f, 0x45, 0xad, // ldp     q6, q7, [sp, #176]
    0xe4, 0x97, 0x44, 0xad, // ldp     q4, q5, [sp, #144]
    0xe2, 0x8f, 0x43, 0xad, // ldp     q2, q3, [sp, #112]
    0xe0, 0x87, 0x42, 0xad, // ldp     q0, q1, [sp, #80]
    0xe6, 0x1f, 0x44, 0xa9, // ldp     x6, x7, [sp, #64]
    0xe4, 0x17, 0x43, 0xa9, // ldp     x4, x5, [sp, #48]
    0xe2, 0x0f, 0x42, 0xa9, // ldp     x2, x3, [sp, #32]
    0xe0, 0x07, 0x41, 0xa9, // ldp     x0, x1, [sp, #16]
    0xfd, 0x7b, 0xcd, 0xa8, // ldp     x29, x30, [sp], #208
    0x00, 0x02, 0x1f, 0xd6, // br      x16
};

// A chunk for the delay import thunk.
class ThunkChunkX64 : public NonSectionChunk {
public:
  ThunkChunkX64(Defined *i, Chunk *tm) : imp(i), tailMerge(tm) {}

  size_t getSize() const override { return sizeof(thunkX64); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, thunkX64, sizeof(thunkX64));
    write32le(buf + 3, imp->getRVA() - rva - 7);
    write32le(buf + 8, tailMerge->getRVA() - rva - 12);
  }

  Defined *imp = nullptr;
  Chunk *tailMerge = nullptr;
};

class TailMergeChunkX64 : public NonSectionChunk {
public:
  TailMergeChunkX64(Chunk *d, Defined *h) : desc(d), helper(h) {}

  size_t getSize() const override { return sizeof(tailMergeX64); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, tailMergeX64, sizeof(tailMergeX64));
    write32le(buf + 39, desc->getRVA() - rva - 43);
    write32le(buf + 44, helper->getRVA() - rva - 48);
  }

  Chunk *desc = nullptr;
  Defined *helper = nullptr;
};

class ThunkChunkX86 : public NonSectionChunk {
public:
  ThunkChunkX86(Defined *i, Chunk *tm) : imp(i), tailMerge(tm) {}

  size_t getSize() const override { return sizeof(thunkX86); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, thunkX86, sizeof(thunkX86));
    write32le(buf + 1, imp->getRVA() + config->imageBase);
    write32le(buf + 6, tailMerge->getRVA() - rva - 10);
  }

  void getBaserels(std::vector<Baserel> *res) override {
    res->emplace_back(rva + 1);
  }

  Defined *imp = nullptr;
  Chunk *tailMerge = nullptr;
};

class TailMergeChunkX86 : public NonSectionChunk {
public:
  TailMergeChunkX86(Chunk *d, Defined *h) : desc(d), helper(h) {}

  size_t getSize() const override { return sizeof(tailMergeX86); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, tailMergeX86, sizeof(tailMergeX86));
    write32le(buf + 4, desc->getRVA() + config->imageBase);
    write32le(buf + 9, helper->getRVA() - rva - 13);
  }

  void getBaserels(std::vector<Baserel> *res) override {
    res->emplace_back(rva + 4);
  }

  Chunk *desc = nullptr;
  Defined *helper = nullptr;
};

class ThunkChunkARM : public NonSectionChunk {
public:
  ThunkChunkARM(Defined *i, Chunk *tm) : imp(i), tailMerge(tm) {
    setAlignment(2);
  }

  size_t getSize() const override { return sizeof(thunkARM); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, thunkARM, sizeof(thunkARM));
    applyMOV32T(buf + 0, imp->getRVA() + config->imageBase);
    applyBranch24T(buf + 8, tailMerge->getRVA() - rva - 12);
  }

  void getBaserels(std::vector<Baserel> *res) override {
    res->emplace_back(rva + 0, IMAGE_REL_BASED_ARM_MOV32T);
  }

  Defined *imp = nullptr;
  Chunk *tailMerge = nullptr;
};

class TailMergeChunkARM : public NonSectionChunk {
public:
  TailMergeChunkARM(Chunk *d, Defined *h) : desc(d), helper(h) {
    setAlignment(2);
  }

  size_t getSize() const override { return sizeof(tailMergeARM); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, tailMergeARM, sizeof(tailMergeARM));
    applyMOV32T(buf + 14, desc->getRVA() + config->imageBase);
    applyBranch24T(buf + 22, helper->getRVA() - rva - 26);
  }

  void getBaserels(std::vector<Baserel> *res) override {
    res->emplace_back(rva + 14, IMAGE_REL_BASED_ARM_MOV32T);
  }

  Chunk *desc = nullptr;
  Defined *helper = nullptr;
};

class ThunkChunkARM64 : public NonSectionChunk {
public:
  ThunkChunkARM64(Defined *i, Chunk *tm) : imp(i), tailMerge(tm) {
    setAlignment(4);
  }

  size_t getSize() const override { return sizeof(thunkARM64); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, thunkARM64, sizeof(thunkARM64));
    applyArm64Addr(buf + 0, imp->getRVA(), rva + 0, 12);
    applyArm64Imm(buf + 4, imp->getRVA() & 0xfff, 0);
    applyArm64Branch26(buf + 8, tailMerge->getRVA() - rva - 8);
  }

  Defined *imp = nullptr;
  Chunk *tailMerge = nullptr;
};

class TailMergeChunkARM64 : public NonSectionChunk {
public:
  TailMergeChunkARM64(Chunk *d, Defined *h) : desc(d), helper(h) {
    setAlignment(4);
  }

  size_t getSize() const override { return sizeof(tailMergeARM64); }

  void writeTo(uint8_t *buf) const override {
    memcpy(buf, tailMergeARM64, sizeof(tailMergeARM64));
    applyArm64Addr(buf + 44, desc->getRVA(), rva + 44, 12);
    applyArm64Imm(buf + 48, desc->getRVA() & 0xfff, 0);
    applyArm64Branch26(buf + 52, helper->getRVA() - rva - 52);
  }

  Chunk *desc = nullptr;
  Defined *helper = nullptr;
};

// A chunk for the import descriptor table.
class DelayAddressChunk : public NonSectionChunk {
public:
  explicit DelayAddressChunk(Chunk *c) : thunk(c) {
    setAlignment(config->wordsize);
  }
  size_t getSize() const override { return config->wordsize; }

  void writeTo(uint8_t *buf) const override {
    if (config->is64()) {
      write64le(buf, thunk->getRVA() + config->imageBase);
    } else {
      uint32_t bit = 0;
      // Pointer to thumb code must have the LSB set, so adjust it.
      if (config->machine == ARMNT)
        bit = 1;
      write32le(buf, (thunk->getRVA() + config->imageBase) | bit);
    }
  }

  void getBaserels(std::vector<Baserel> *res) override {
    res->emplace_back(rva);
  }

  Chunk *thunk;
};

// Export table
// Read Microsoft PE/COFF spec 5.3 for details.

// A chunk for the export descriptor table.
class ExportDirectoryChunk : public NonSectionChunk {
public:
  ExportDirectoryChunk(int i, int j, Chunk *d, Chunk *a, Chunk *n, Chunk *o)
      : maxOrdinal(i), nameTabSize(j), dllName(d), addressTab(a), nameTab(n),
        ordinalTab(o) {}

  size_t getSize() const override {
    return sizeof(export_directory_table_entry);
  }

  void writeTo(uint8_t *buf) const override {
    memset(buf, 0, getSize());

    auto *e = (export_directory_table_entry *)(buf);
    e->NameRVA = dllName->getRVA();
    e->OrdinalBase = 0;
    e->AddressTableEntries = maxOrdinal + 1;
    e->NumberOfNamePointers = nameTabSize;
    e->ExportAddressTableRVA = addressTab->getRVA();
    e->NamePointerRVA = nameTab->getRVA();
    e->OrdinalTableRVA = ordinalTab->getRVA();
  }

  uint16_t maxOrdinal;
  uint16_t nameTabSize;
  Chunk *dllName;
  Chunk *addressTab;
  Chunk *nameTab;
  Chunk *ordinalTab;
};

class AddressTableChunk : public NonSectionChunk {
public:
  explicit AddressTableChunk(size_t maxOrdinal) : size(maxOrdinal + 1) {}
  size_t getSize() const override { return size * 4; }

  void writeTo(uint8_t *buf) const override {
    memset(buf, 0, getSize());

    for (const Export &e : config->exports) {
      uint8_t *p = buf + e.ordinal * 4;
      uint32_t bit = 0;
      // Pointer to thumb code must have the LSB set, so adjust it.
      if (config->machine == ARMNT && !e.data)
        bit = 1;
      if (e.forwardChunk) {
        write32le(p, e.forwardChunk->getRVA() | bit);
      } else {
        write32le(p, cast<Defined>(e.sym)->getRVA() | bit);
      }
    }
  }

private:
  size_t size;
};

class NamePointersChunk : public NonSectionChunk {
public:
  explicit NamePointersChunk(std::vector<Chunk *> &v) : chunks(v) {}
  size_t getSize() const override { return chunks.size() * 4; }

  void writeTo(uint8_t *buf) const override {
    for (Chunk *c : chunks) {
      write32le(buf, c->getRVA());
      buf += 4;
    }
  }

private:
  std::vector<Chunk *> chunks;
};

class ExportOrdinalChunk : public NonSectionChunk {
public:
  explicit ExportOrdinalChunk(size_t i) : size(i) {}
  size_t getSize() const override { return size * 2; }

  void writeTo(uint8_t *buf) const override {
    for (Export &e : config->exports) {
      if (e.noname)
        continue;
      write16le(buf, e.ordinal);
      buf += 2;
    }
  }

private:
  size_t size;
};

} // anonymous namespace

void IdataContents::create() {
  std::vector<std::vector<DefinedImportData *>> v = binImports(imports);

  // Create .idata contents for each DLL.
  for (std::vector<DefinedImportData *> &syms : v) {
    // Create lookup and address tables. If they have external names,
    // we need to create hintName chunks to store the names.
    // If they don't (if they are import-by-ordinals), we store only
    // ordinal values to the table.
    size_t base = lookups.size();
    for (DefinedImportData *s : syms) {
      uint16_t ord = s->getOrdinal();
      if (s->getExternalName().empty()) {
        lookups.push_back(make<OrdinalOnlyChunk>(ord));
        addresses.push_back(make<OrdinalOnlyChunk>(ord));
        continue;
      }
      auto *c = make<HintNameChunk>(s->getExternalName(), ord);
      lookups.push_back(make<LookupChunk>(c));
      addresses.push_back(make<LookupChunk>(c));
      hints.push_back(c);
    }
    // Terminate with null values.
    lookups.push_back(make<NullChunk>(config->wordsize));
    addresses.push_back(make<NullChunk>(config->wordsize));

    for (int i = 0, e = syms.size(); i < e; ++i)
      syms[i]->setLocation(addresses[base + i]);

    // Create the import table header.
    dllNames.push_back(make<StringChunk>(syms[0]->getDLLName()));
    auto *dir = make<ImportDirectoryChunk>(dllNames.back());
    dir->lookupTab = lookups[base];
    dir->addressTab = addresses[base];
    dirs.push_back(dir);
  }
  // Add null terminator.
  dirs.push_back(make<NullChunk>(sizeof(ImportDirectoryTableEntry)));
}

std::vector<Chunk *> DelayLoadContents::getChunks() {
  std::vector<Chunk *> v;
  v.insert(v.end(), dirs.begin(), dirs.end());
  v.insert(v.end(), names.begin(), names.end());
  v.insert(v.end(), hintNames.begin(), hintNames.end());
  v.insert(v.end(), dllNames.begin(), dllNames.end());
  return v;
}

std::vector<Chunk *> DelayLoadContents::getDataChunks() {
  std::vector<Chunk *> v;
  v.insert(v.end(), moduleHandles.begin(), moduleHandles.end());
  v.insert(v.end(), addresses.begin(), addresses.end());
  return v;
}

uint64_t DelayLoadContents::getDirSize() {
  return dirs.size() * sizeof(delay_import_directory_table_entry);
}

void DelayLoadContents::create(Defined *h) {
  helper = h;
  std::vector<std::vector<DefinedImportData *>> v = binImports(imports);

  // Create .didat contents for each DLL.
  for (std::vector<DefinedImportData *> &syms : v) {
    // Create the delay import table header.
    dllNames.push_back(make<StringChunk>(syms[0]->getDLLName()));
    auto *dir = make<DelayDirectoryChunk>(dllNames.back());

    size_t base = addresses.size();
    Chunk *tm = newTailMergeChunk(dir);
    for (DefinedImportData *s : syms) {
      Chunk *t = newThunkChunk(s, tm);
      auto *a = make<DelayAddressChunk>(t);
      addresses.push_back(a);
      thunks.push_back(t);
      StringRef extName = s->getExternalName();
      if (extName.empty()) {
        names.push_back(make<OrdinalOnlyChunk>(s->getOrdinal()));
      } else {
        auto *c = make<HintNameChunk>(extName, 0);
        names.push_back(make<LookupChunk>(c));
        hintNames.push_back(c);
      }
    }
    thunks.push_back(tm);
    // Terminate with null values.
    addresses.push_back(make<NullChunk>(8));
    names.push_back(make<NullChunk>(8));

    for (int i = 0, e = syms.size(); i < e; ++i)
      syms[i]->setLocation(addresses[base + i]);
    auto *mh = make<NullChunk>(8);
    mh->setAlignment(8);
    moduleHandles.push_back(mh);

    // Fill the delay import table header fields.
    dir->moduleHandle = mh;
    dir->addressTab = addresses[base];
    dir->nameTab = names[base];
    dirs.push_back(dir);
  }
  // Add null terminator.
  dirs.push_back(make<NullChunk>(sizeof(delay_import_directory_table_entry)));
}

Chunk *DelayLoadContents::newTailMergeChunk(Chunk *dir) {
  switch (config->machine) {
  case AMD64:
    return make<TailMergeChunkX64>(dir, helper);
  case I386:
    return make<TailMergeChunkX86>(dir, helper);
  case ARMNT:
    return make<TailMergeChunkARM>(dir, helper);
  case ARM64:
    return make<TailMergeChunkARM64>(dir, helper);
  default:
    llvm_unreachable("unsupported machine type");
  }
}

Chunk *DelayLoadContents::newThunkChunk(DefinedImportData *s,
                                        Chunk *tailMerge) {
  switch (config->machine) {
  case AMD64:
    return make<ThunkChunkX64>(s, tailMerge);
  case I386:
    return make<ThunkChunkX86>(s, tailMerge);
  case ARMNT:
    return make<ThunkChunkARM>(s, tailMerge);
  case ARM64:
    return make<ThunkChunkARM64>(s, tailMerge);
  default:
    llvm_unreachable("unsupported machine type");
  }
}

EdataContents::EdataContents() {
  uint16_t maxOrdinal = 0;
  for (Export &e : config->exports)
    maxOrdinal = std::max(maxOrdinal, e.ordinal);

  auto *dllName = make<StringChunk>(sys::path::filename(config->outputFile));
  auto *addressTab = make<AddressTableChunk>(maxOrdinal);
  std::vector<Chunk *> names;
  for (Export &e : config->exports)
    if (!e.noname)
      names.push_back(make<StringChunk>(e.exportName));

  std::vector<Chunk *> forwards;
  for (Export &e : config->exports) {
    if (e.forwardTo.empty())
      continue;
    e.forwardChunk = make<StringChunk>(e.forwardTo);
    forwards.push_back(e.forwardChunk);
  }

  auto *nameTab = make<NamePointersChunk>(names);
  auto *ordinalTab = make<ExportOrdinalChunk>(names.size());
  auto *dir = make<ExportDirectoryChunk>(maxOrdinal, names.size(), dllName,
                                         addressTab, nameTab, ordinalTab);
  chunks.push_back(dir);
  chunks.push_back(dllName);
  chunks.push_back(addressTab);
  chunks.push_back(nameTab);
  chunks.push_back(ordinalTab);
  chunks.insert(chunks.end(), names.begin(), names.end());
  chunks.insert(chunks.end(), forwards.begin(), forwards.end());
}

} // namespace coff
} // namespace lld