1 //===- MCObjectStreamer.h - MCStreamer Object File Interface ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCOBJECTSTREAMER_H
11 #define LLVM_MC_MCOBJECTSTREAMER_H
13 #include "llvm/ADT/SmallVector.h"
14 #include "llvm/MC/MCAssembler.h"
15 #include "llvm/MC/MCSection.h"
16 #include "llvm/MC/MCStreamer.h"
21 class MCSubtargetInfo;
27 class raw_pwrite_stream;
29 /// Streaming object file generation interface.
31 /// This class provides an implementation of the MCStreamer interface which is
32 /// suitable for use with the assembler backend. Specific object file formats
33 /// are expected to subclass this interface to implement directives specific
34 /// to that file format or custom semantics expected by the object writer
36 class MCObjectStreamer : public MCStreamer {
37 std::unique_ptr<MCAssembler> Assembler;
38 MCSection::iterator CurInsertionPoint;
41 SmallVector<MCSymbol *, 2> PendingLabels;
43 virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0;
44 void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
45 void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
46 MCSymbol *EmitCFILabel() override;
47 void EmitInstructionImpl(const MCInst &Inst, const MCSubtargetInfo &STI);
50 MCObjectStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
51 std::unique_ptr<MCObjectWriter> OW,
52 std::unique_ptr<MCCodeEmitter> Emitter);
57 void reset() override;
59 /// Object streamers require the integrated assembler.
60 bool isIntegratedAssemblerRequired() const override { return true; }
62 void EmitFrames(MCAsmBackend *MAB);
63 void EmitCFISections(bool EH, bool Debug) override;
65 MCFragment *getCurrentFragment() const;
67 void insert(MCFragment *F) {
68 flushPendingLabels(F);
69 MCSection *CurSection = getCurrentSectionOnly();
70 CurSection->getFragmentList().insert(CurInsertionPoint, F);
71 F->setParent(CurSection);
74 /// Get a data fragment to write into, creating a new one if the current
75 /// fragment is not a data fragment.
76 /// Optionally a \p STI can be passed in so that a new fragment is created
77 /// if the Subtarget differs from the current fragment.
78 MCDataFragment *getOrCreateDataFragment(const MCSubtargetInfo* STI = nullptr);
79 MCPaddingFragment *getOrCreatePaddingFragment();
82 bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection);
84 /// If any labels have been emitted but not assigned fragments, ensure that
85 /// they get assigned, either to F if possible or to a new data fragment.
86 /// Optionally, it is also possible to provide an offset \p FOffset, which
87 /// will be used as a symbol offset within the fragment.
88 void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0);
91 void visitUsedSymbol(const MCSymbol &Sym) override;
93 /// Create a dummy fragment to assign any pending labels.
94 void flushPendingLabels() { flushPendingLabels(nullptr); }
96 MCAssembler &getAssembler() { return *Assembler; }
97 MCAssembler *getAssemblerPtr() override;
98 /// \name MCStreamer Interface
101 void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
102 virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F);
103 void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
104 void EmitValueImpl(const MCExpr *Value, unsigned Size,
105 SMLoc Loc = SMLoc()) override;
106 void EmitULEB128Value(const MCExpr *Value) override;
107 void EmitSLEB128Value(const MCExpr *Value) override;
108 void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
109 void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
110 void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
111 bool = false) override;
113 /// Emit an instruction to a special fragment, because this instruction
114 /// can change its size during relaxation.
115 virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &);
117 void EmitBundleAlignMode(unsigned AlignPow2) override;
118 void EmitBundleLock(bool AlignToEnd) override;
119 void EmitBundleUnlock() override;
120 void EmitBytes(StringRef Data) override;
121 void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
122 unsigned ValueSize = 1,
123 unsigned MaxBytesToEmit = 0) override;
124 void EmitCodeAlignment(unsigned ByteAlignment,
125 unsigned MaxBytesToEmit = 0) override;
126 void emitValueToOffset(const MCExpr *Offset, unsigned char Value,
129 EmitCodePaddingBasicBlockStart(const MCCodePaddingContext &Context) override;
131 EmitCodePaddingBasicBlockEnd(const MCCodePaddingContext &Context) override;
132 void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
133 unsigned Column, unsigned Flags,
134 unsigned Isa, unsigned Discriminator,
135 StringRef FileName) override;
136 void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
137 const MCSymbol *Label,
138 unsigned PointerSize);
139 void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
140 const MCSymbol *Label);
141 void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line,
142 unsigned Column, bool PrologueEnd, bool IsStmt,
143 StringRef FileName, SMLoc Loc) override;
144 void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin,
145 const MCSymbol *End) override;
146 void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
147 unsigned SourceFileId,
148 unsigned SourceLineNum,
149 const MCSymbol *FnStartSym,
150 const MCSymbol *FnEndSym) override;
151 void EmitCVDefRangeDirective(
152 ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
153 StringRef FixedSizePortion) override;
154 void EmitCVStringTableDirective() override;
155 void EmitCVFileChecksumsDirective() override;
156 void EmitCVFileChecksumOffsetDirective(unsigned FileNo) override;
157 void EmitDTPRel32Value(const MCExpr *Value) override;
158 void EmitDTPRel64Value(const MCExpr *Value) override;
159 void EmitTPRel32Value(const MCExpr *Value) override;
160 void EmitTPRel64Value(const MCExpr *Value) override;
161 void EmitGPRel32Value(const MCExpr *Value) override;
162 void EmitGPRel64Value(const MCExpr *Value) override;
163 bool EmitRelocDirective(const MCExpr &Offset, StringRef Name,
164 const MCExpr *Expr, SMLoc Loc,
165 const MCSubtargetInfo &STI) override;
166 using MCStreamer::emitFill;
167 void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
168 SMLoc Loc = SMLoc()) override;
169 void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
170 SMLoc Loc = SMLoc()) override;
171 void EmitFileDirective(StringRef Filename) override;
173 void EmitAddrsig() override;
174 void EmitAddrsigSym(const MCSymbol *Sym) override;
176 void FinishImpl() override;
178 /// Emit the absolute difference between two symbols if possible.
180 /// Emit the absolute difference between \c Hi and \c Lo, as long as we can
181 /// compute it. Currently, that requires that both symbols are in the same
182 /// data fragment. Otherwise, do nothing and return \c false.
184 /// \pre Offset of \c Hi is greater than the offset \c Lo.
185 void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
186 unsigned Size) override;
188 void emitAbsoluteSymbolDiffAsULEB128(const MCSymbol *Hi,
189 const MCSymbol *Lo) override;
191 bool mayHaveInstructions(MCSection &Sec) const override;
194 } // end namespace llvm