1 //===- MCELFStreamer.h - MCStreamer ELF Object File Interface ---*- 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 #ifndef LLVM_MC_MCELFSTREAMER_H
10 #define LLVM_MC_MCELFSTREAMER_H
11 
12 #include "llvm/ADT/SmallVector.h"
13 #include "llvm/MC/MCDirectives.h"
14 #include "llvm/MC/MCObjectStreamer.h"
15 
16 namespace llvm {
17 
18 class MCAsmBackend;
19 class MCCodeEmitter;
20 class MCExpr;
21 class MCInst;
22 
23 class MCELFStreamer : public MCObjectStreamer {
24 public:
25   MCELFStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
26                 std::unique_ptr<MCObjectWriter> OW,
27                 std::unique_ptr<MCCodeEmitter> Emitter);
28 
29   ~MCELFStreamer() override = default;
30 
31   /// state management
reset()32   void reset() override {
33     SeenIdent = false;
34     BundleGroups.clear();
35     MCObjectStreamer::reset();
36   }
37 
38   /// \name MCStreamer Interface
39   /// @{
40 
41   void InitSections(bool NoExecStack) override;
42   void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
43   void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
44   void EmitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCFragment *F,
45                       uint64_t Offset) override;
46   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
47   void EmitThumbFunc(MCSymbol *Func) override;
48   void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
49   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
50   void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override;
51   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
52                         unsigned ByteAlignment) override;
53 
54   void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
55   void emitELFSymverDirective(StringRef AliasName,
56                               const MCSymbol *Aliasee) override;
57 
58   void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
59                              unsigned ByteAlignment) override;
60 
61   void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
62                     uint64_t Size = 0, unsigned ByteAlignment = 0,
63                     SMLoc L = SMLoc()) override;
64   void EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
65                       unsigned ByteAlignment = 0) override;
66   void EmitValueImpl(const MCExpr *Value, unsigned Size,
67                      SMLoc Loc = SMLoc()) override;
68 
69   void EmitIdent(StringRef IdentString) override;
70 
71   void EmitValueToAlignment(unsigned, int64_t, unsigned, unsigned) override;
72 
73   void emitCGProfileEntry(const MCSymbolRefExpr *From,
74                           const MCSymbolRefExpr *To, uint64_t Count) override;
75 
76   void FinishImpl() override;
77 
78   void EmitBundleAlignMode(unsigned AlignPow2) override;
79   void EmitBundleLock(bool AlignToEnd) override;
80   void EmitBundleUnlock() override;
81 
82 private:
83   bool isBundleLocked() const;
84   void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &) override;
85   void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo &) override;
86 
87   void fixSymbolsInTLSFixups(const MCExpr *expr);
88   void finalizeCGProfileEntry(const MCSymbolRefExpr *&S);
89   void finalizeCGProfile();
90 
91   /// Merge the content of the fragment \p EF into the fragment \p DF.
92   void mergeFragment(MCDataFragment *, MCDataFragment *);
93 
94   bool SeenIdent = false;
95 
96   /// BundleGroups - The stack of fragments holding the bundle-locked
97   /// instructions.
98   SmallVector<MCDataFragment *, 4> BundleGroups;
99 };
100 
101 MCELFStreamer *createARMELFStreamer(MCContext &Context,
102                                     std::unique_ptr<MCAsmBackend> TAB,
103                                     std::unique_ptr<MCObjectWriter> OW,
104                                     std::unique_ptr<MCCodeEmitter> Emitter,
105                                     bool RelaxAll, bool IsThumb, bool IsAndroid);
106 
107 } // end namespace llvm
108 
109 #endif // LLVM_MC_MCELFSTREAMER_H
110