MCAsmBackend.cpp 3.8 KB

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  1. //===- MCAsmBackend.cpp - Target MC Assembly Backend ----------------------===//
  2. //
  3. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4. // See https://llvm.org/LICENSE.txt for license information.
  5. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6. //
  7. //===----------------------------------------------------------------------===//
  8. #include "llvm/MC/MCAsmBackend.h"
  9. #include "llvm/ADT/None.h"
  10. #include "llvm/ADT/STLExtras.h"
  11. #include "llvm/MC/MCELFObjectWriter.h"
  12. #include "llvm/MC/MCFixupKindInfo.h"
  13. #include "llvm/MC/MCMachObjectWriter.h"
  14. #include "llvm/MC/MCObjectWriter.h"
  15. #include "llvm/MC/MCWasmObjectWriter.h"
  16. #include "llvm/MC/MCWinCOFFObjectWriter.h"
  17. #include "llvm/MC/MCXCOFFObjectWriter.h"
  18. #include <cassert>
  19. #include <cstddef>
  20. #include <cstdint>
  21. using namespace llvm;
  22. MCAsmBackend::MCAsmBackend(support::endianness Endian) : Endian(Endian) {}
  23. MCAsmBackend::~MCAsmBackend() = default;
  24. std::unique_ptr<MCObjectWriter>
  25. MCAsmBackend::createObjectWriter(raw_pwrite_stream &OS) const {
  26. auto TW = createObjectTargetWriter();
  27. switch (TW->getFormat()) {
  28. case Triple::ELF:
  29. return createELFObjectWriter(cast<MCELFObjectTargetWriter>(std::move(TW)), OS,
  30. Endian == support::little);
  31. case Triple::MachO:
  32. return createMachObjectWriter(cast<MCMachObjectTargetWriter>(std::move(TW)),
  33. OS, Endian == support::little);
  34. case Triple::COFF:
  35. return createWinCOFFObjectWriter(
  36. cast<MCWinCOFFObjectTargetWriter>(std::move(TW)), OS);
  37. case Triple::Wasm:
  38. return createWasmObjectWriter(cast<MCWasmObjectTargetWriter>(std::move(TW)),
  39. OS);
  40. case Triple::XCOFF:
  41. return createXCOFFObjectWriter(
  42. cast<MCXCOFFObjectTargetWriter>(std::move(TW)), OS);
  43. default:
  44. llvm_unreachable("unexpected object format");
  45. }
  46. }
  47. std::unique_ptr<MCObjectWriter>
  48. MCAsmBackend::createDwoObjectWriter(raw_pwrite_stream &OS,
  49. raw_pwrite_stream &DwoOS) const {
  50. auto TW = createObjectTargetWriter();
  51. switch (TW->getFormat()) {
  52. case Triple::ELF:
  53. return createELFDwoObjectWriter(
  54. cast<MCELFObjectTargetWriter>(std::move(TW)), OS, DwoOS,
  55. Endian == support::little);
  56. case Triple::Wasm:
  57. return createWasmDwoObjectWriter(
  58. cast<MCWasmObjectTargetWriter>(std::move(TW)), OS, DwoOS);
  59. default:
  60. report_fatal_error("dwo only supported with ELF and Wasm");
  61. }
  62. }
  63. Optional<MCFixupKind> MCAsmBackend::getFixupKind(StringRef Name) const {
  64. return None;
  65. }
  66. const MCFixupKindInfo &MCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
  67. static const MCFixupKindInfo Builtins[] = {
  68. {"FK_NONE", 0, 0, 0},
  69. {"FK_Data_1", 0, 8, 0},
  70. {"FK_Data_2", 0, 16, 0},
  71. {"FK_Data_4", 0, 32, 0},
  72. {"FK_Data_8", 0, 64, 0},
  73. {"FK_Data_6b", 0, 6, 0},
  74. {"FK_PCRel_1", 0, 8, MCFixupKindInfo::FKF_IsPCRel},
  75. {"FK_PCRel_2", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
  76. {"FK_PCRel_4", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
  77. {"FK_PCRel_8", 0, 64, MCFixupKindInfo::FKF_IsPCRel},
  78. {"FK_GPRel_1", 0, 8, 0},
  79. {"FK_GPRel_2", 0, 16, 0},
  80. {"FK_GPRel_4", 0, 32, 0},
  81. {"FK_GPRel_8", 0, 64, 0},
  82. {"FK_DTPRel_4", 0, 32, 0},
  83. {"FK_DTPRel_8", 0, 64, 0},
  84. {"FK_TPRel_4", 0, 32, 0},
  85. {"FK_TPRel_8", 0, 64, 0},
  86. {"FK_SecRel_1", 0, 8, 0},
  87. {"FK_SecRel_2", 0, 16, 0},
  88. {"FK_SecRel_4", 0, 32, 0},
  89. {"FK_SecRel_8", 0, 64, 0},
  90. };
  91. assert((size_t)Kind <= array_lengthof(Builtins) && "Unknown fixup kind");
  92. return Builtins[Kind];
  93. }
  94. bool MCAsmBackend::fixupNeedsRelaxationAdvanced(
  95. const MCFixup &Fixup, bool Resolved, uint64_t Value,
  96. const MCRelaxableFragment *DF, const MCAsmLayout &Layout,
  97. const bool WasForced) const {
  98. if (!Resolved)
  99. return true;
  100. return fixupNeedsRelaxation(Fixup, Value, DF, Layout);
  101. }