LLVM  12.0.0git
Go to the documentation of this file.
1 //===-- AVRAsmBackend.h - AVR Asm 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 //
9 // \file The AVR assembly backend implementation.
10 //
11 //===----------------------------------------------------------------------===//
12 //
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/MC/MCAsmBackend.h"
22 namespace llvm {
24 class MCAssembler;
25 struct MCFixupKindInfo;
27 /// Utilities for manipulating generated AVR machine code.
28 class AVRAsmBackend : public MCAsmBackend {
29 public:
31  : MCAsmBackend(support::little), OSType(OSType) {}
33  void adjustFixupValue(const MCFixup &Fixup, const MCValue &Target,
34  uint64_t &Value, MCContext *Ctx = nullptr) const;
36  std::unique_ptr<MCObjectTargetWriter>
37  createObjectTargetWriter() const override;
39  void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
40  const MCValue &Target, MutableArrayRef<char> Data,
41  uint64_t Value, bool IsResolved,
42  const MCSubtargetInfo *STI) const override;
44  const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
46  unsigned getNumFixupKinds() const override {
48  }
50  bool mayNeedRelaxation(const MCInst &Inst,
51  const MCSubtargetInfo &STI) const override {
52  return false;
53  }
55  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
56  const MCRelaxableFragment *DF,
57  const MCAsmLayout &Layout) const override {
58  llvm_unreachable("RelaxInstruction() unimplemented");
59  return false;
60  }
62  bool writeNopData(raw_ostream &OS, uint64_t Count) const override;
64  bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
65  const MCValue &Target) override;
67 private:
68  Triple::OSType OSType;
69 };
71 } // end namespace llvm
AVRAsmBackend(Triple::OSType OSType)
Definition: AVRAsmBackend.h:30
unsigned getNumFixupKinds() const override
Get the number of target specific fixup kinds.
Definition: AVRAsmBackend.h:46
This class represents lattice values for constants.
Definition: AllocatorList.h:23
This represents an "assembler immediate".
Definition: MCValue.h:37
bool writeNopData(raw_ostream &OS, uint64_t Count) const override
Write an (optimal) nop sequence of Count bytes to the given output.
bool mayNeedRelaxation(const MCInst &Inst, const MCSubtargetInfo &STI) const override
Check whether the given instruction may need relaxation.
Definition: AVRAsmBackend.h:50
bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value, const MCRelaxableFragment *DF, const MCAsmLayout &Layout) const override
Simple predicate for targets where !Resolved implies requiring relaxation.
Definition: AVRAsmBackend.h:55
bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup, const MCValue &Target) override
Hook to check if a relocation is needed for some target specific reason.
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:82
Encapsulates the layout of an assembly file at a particular point in time.
Definition: MCAsmLayout.h:28
std::unique_ptr< MCObjectTargetWriter > createObjectTargetWriter() const override
Context object for machine code objects.
Definition: MCContext.h:67
Utilities for manipulating generated AVR machine code.
Definition: AVRAsmBackend.h:28
Instances of this class represent a single low-level machine instruction.
Definition: MCInst.h:158
A relaxable fragment holds on to its MCInst, since it may need to be relaxed during the assembler lay...
Definition: MCFragment.h:261
MutableArrayRef - Represent a mutable reference to an array (0 or more elements consecutively in memo...
Definition: ArrayRef.h:298
const MCFixupKindInfo & getFixupKindInfo(MCFixupKind Kind) const override
Get information on a fixup kind.
Extensible enumeration to represent the type of a fixup.
Definition: MCFixup.h:22
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
static RegisterPass< DebugifyFunctionPass > DF("debugify-function", "Attach debug info to a function")
PowerPC TLS Dynamic Call Fixup
Target - Wrapper for Target specific information.
Generic base class for all target subtargets.
Target independent information on a fixup kind.
LLVM Value Representation.
Definition: Value.h:74
Generic interface to target specific assembler backends.
Definition: MCAsmBackend.h:36
void adjustFixupValue(const MCFixup &Fixup, const MCValue &Target, uint64_t &Value, MCContext *Ctx=nullptr) const
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:46
void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup, const MCValue &Target, MutableArrayRef< char > Data, uint64_t Value, bool IsResolved, const MCSubtargetInfo *STI) const override
Apply the Value for given Fixup into the provided data fragment, at the offset specified by the fixup...