1//===- MipsELFStreamer.h - ELF Object Output --------------------*- C++ -*-===//
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// This is a custom MCELFStreamer which allows us to insert some hooks before
10// emitting data into an actual object file.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H
15#define LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H
16
17#include "MipsOptionRecord.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/MC/MCELFStreamer.h"
20#include <memory>
21
22namespace llvm {
23
24class MCAsmBackend;
25class MCCodeEmitter;
26class MCContext;
27class MCSubtargetInfo;
28struct MCDwarfFrameInfo;
29
30class MipsELFStreamer : public MCELFStreamer {
31  SmallVector<std::unique_ptr<MipsOptionRecord>, 8> MipsOptionRecords;
32  MipsRegInfoRecord *RegInfoRecord;
33  SmallVector<MCSymbol*, 4> Labels;
34
35public:
36  MipsELFStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> MAB,
37                  std::unique_ptr<MCObjectWriter> OW,
38                  std::unique_ptr<MCCodeEmitter> Emitter);
39
40  /// Overriding this function allows us to add arbitrary behaviour before the
41  /// \p Inst is actually emitted. For example, we can inspect the operands and
42  /// gather sufficient information that allows us to reason about the register
43  /// usage for the translation unit.
44  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override;
45
46  /// Overriding this function allows us to record all labels that should be
47  /// marked as microMIPS. Based on this data marking is done in
48  /// EmitInstruction.
49  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
50
51  /// Overriding this function allows us to dismiss all labels that are
52  /// candidates for marking as microMIPS when .section directive is processed.
53  void SwitchSection(MCSection *Section,
54                     const MCExpr *Subsection = nullptr) override;
55
56  /// Overriding these functions allows us to dismiss all labels that are
57  /// candidates for marking as microMIPS when .word/.long/.4byte etc
58  /// directives are emitted.
59  void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override;
60  void EmitIntValue(uint64_t Value, unsigned Size) override;
61
62  // Overriding these functions allows us to avoid recording of these labels
63  // in EmitLabel and later marking them as microMIPS.
64  void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
65  void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
66  MCSymbol *EmitCFILabel() override;
67
68  /// Emits all the option records stored up until the point it's called.
69  void EmitMipsOptionRecords();
70
71  /// Mark labels as microMIPS, if necessary for the subtarget.
72  void createPendingLabelRelocs();
73};
74
75MCELFStreamer *createMipsELFStreamer(MCContext &Context,
76                                     std::unique_ptr<MCAsmBackend> MAB,
77                                     std::unique_ptr<MCObjectWriter> OW,
78                                     std::unique_ptr<MCCodeEmitter> Emitter,
79                                     bool RelaxAll);
80} // end namespace llvm
81
82#endif // LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H
83