1//===-------- MipsELFStreamer.h - ELF Object Output -----------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This is a custom MCELFStreamer which allows us to insert some hooks before
11// emitting data into an actual object file.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H
16#define LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H
17
18#include "MipsOptionRecord.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/MC/MCELFStreamer.h"
21#include <memory>
22
23namespace llvm {
24class MCAsmBackend;
25class MCCodeEmitter;
26class MCContext;
27class MCSubtargetInfo;
28
29class MipsELFStreamer : public MCELFStreamer {
30  SmallVector<std::unique_ptr<MipsOptionRecord>, 8> MipsOptionRecords;
31  MipsRegInfoRecord *RegInfoRecord;
32  SmallVector<MCSymbol*, 4> Labels;
33
34
35public:
36  MipsELFStreamer(MCContext &Context, MCAsmBackend &MAB, raw_pwrite_stream &OS,
37                  MCCodeEmitter *Emitter)
38      : MCELFStreamer(Context, MAB, OS, Emitter) {
39
40    RegInfoRecord = new MipsRegInfoRecord(this, Context);
41    MipsOptionRecords.push_back(
42        std::unique_ptr<MipsRegInfoRecord>(RegInfoRecord));
43  }
44
45  /// Overriding this function allows us to add arbitrary behaviour before the
46  /// \p Inst is actually emitted. For example, we can inspect the operands and
47  /// gather sufficient information that allows us to reason about the register
48  /// usage for the translation unit.
49  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override;
50
51  /// Overriding this function allows us to record all labels that should be
52  /// marked as microMIPS. Based on this data marking is done in
53  /// EmitInstruction.
54  void EmitLabel(MCSymbol *Symbol) override;
55
56  /// Overriding this function allows us to dismiss all labels that are
57  /// candidates for marking as microMIPS when .section directive is processed.
58  void SwitchSection(MCSection *Section,
59                     const MCExpr *Subsection = nullptr) override;
60
61  /// Overriding this function allows us to dismiss all labels that are
62  /// candidates for marking as microMIPS when .word directive is emitted.
63  void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override;
64
65  /// Emits all the option records stored up until the point it's called.
66  void EmitMipsOptionRecords();
67
68  /// Mark labels as microMIPS, if necessary for the subtarget.
69  void createPendingLabelRelocs();
70};
71
72MCELFStreamer *createMipsELFStreamer(MCContext &Context, MCAsmBackend &MAB,
73                                     raw_pwrite_stream &OS,
74                                     MCCodeEmitter *Emitter, bool RelaxAll);
75} // namespace llvm.
76#endif
77