LLVM  8.0.0svn
MCObjectStreamer.h
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1 //===- MCObjectStreamer.h - MCStreamer Object File Interface ----*- C++ -*-===//
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 #ifndef LLVM_MC_MCOBJECTSTREAMER_H
11 #define LLVM_MC_MCOBJECTSTREAMER_H
12 
13 #include "llvm/ADT/SmallVector.h"
14 #include "llvm/MC/MCAssembler.h"
15 #include "llvm/MC/MCSection.h"
16 #include "llvm/MC/MCStreamer.h"
17 
18 namespace llvm {
19 class MCAssembler;
20 class MCCodeEmitter;
21 class MCSubtargetInfo;
22 class MCExpr;
23 class MCFragment;
24 class MCDataFragment;
25 class MCAsmBackend;
26 class raw_ostream;
27 class raw_pwrite_stream;
28 
29 /// Streaming object file generation interface.
30 ///
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
35 /// implementation.
36 class MCObjectStreamer : public MCStreamer {
37  std::unique_ptr<MCAssembler> Assembler;
38  MCSection::iterator CurInsertionPoint;
39  bool EmitEHFrame;
40  bool EmitDebugFrame;
41  SmallVector<MCSymbol *, 2> PendingLabels;
42 
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);
48 
49 protected:
50  MCObjectStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
51  std::unique_ptr<MCObjectWriter> OW,
52  std::unique_ptr<MCCodeEmitter> Emitter);
54 
55 public:
56  /// state management
57  void reset() override;
58 
59  /// Object streamers require the integrated assembler.
60  bool isIntegratedAssemblerRequired() const override { return true; }
61 
62  void EmitFrames(MCAsmBackend *MAB);
63  void EmitCFISections(bool EH, bool Debug) override;
64 
66 
67  void insert(MCFragment *F) {
69  MCSection *CurSection = getCurrentSectionOnly();
70  CurSection->getFragmentList().insert(CurInsertionPoint, F);
71  F->setParent(CurSection);
72  }
73 
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.
80 
81 protected:
82  bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection);
83 
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);
89 
90 public:
91  void visitUsedSymbol(const MCSymbol &Sym) override;
92 
93  /// Create a dummy fragment to assign any pending labels.
95 
96  MCAssembler &getAssembler() { return *Assembler; }
97  MCAssembler *getAssemblerPtr() override;
98  /// \name MCStreamer Interface
99  /// @{
100 
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;
112 
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 &);
116 
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,
127  SMLoc Loc) override;
128  void
129  EmitCodePaddingBasicBlockStart(const MCCodePaddingContext &Context) override;
130  void
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;
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;
172 
173  void EmitAddrsig() override;
174  void EmitAddrsigSym(const MCSymbol *Sym) override;
175 
176  void FinishImpl() override;
177 
178  /// Emit the absolute difference between two symbols if possible.
179  ///
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 and that the target has not specified that diff expressions
183  /// require relocations to be emitted. Otherwise, do nothing and return
184  /// \c false.
185  ///
186  /// \pre Offset of \c Hi is greater than the offset \c Lo.
187  void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
188  unsigned Size) override;
189 
191  const MCSymbol *Lo) override;
192 
193  bool mayHaveInstructions(MCSection &Sec) const override;
194 };
195 
196 } // end namespace llvm
197 
198 #endif
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:39
Fragment for adding required padding.
Definition: MCFragment.h:341
void EmitBytes(StringRef Data) override
Emit the bytes in Data into the output.
bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection)
LLVMContext & Context
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
void EmitCodePaddingBasicBlockStart(const MCCodePaddingContext &Context) override
virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &)
Emit an instruction to a special fragment, because this instruction can change its size during relaxa...
F(f)
void EmitCVFileChecksumOffsetDirective(unsigned FileNo) override
This implements the CodeView &#39;.cv_filechecksumoffset&#39; assembler directive.
void EmitCVDefRangeDirective(ArrayRef< std::pair< const MCSymbol *, const MCSymbol *>> Ranges, StringRef FixedSizePortion) override
This implements the CodeView &#39;.cv_def_range&#39; assembler directive.
void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, const MCSymbol *Label, unsigned PointerSize)
void EmitCVStringTableDirective() override
This implements the CodeView &#39;.cv_stringtable&#39; assembler directive.
void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override
Emit an weak reference from Alias to Symbol.
bool EmitRelocDirective(const MCExpr &Offset, StringRef Name, const MCExpr *Expr, SMLoc Loc, const MCSubtargetInfo &STI) override
Emit a .reloc directive.
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:36
bool mayHaveInstructions(MCSection &Sec) const override
void flushPendingLabels()
Create a dummy fragment to assign any pending labels.
void EmitBundleLock(bool AlignToEnd) override
The following instructions are a bundle-locked group.
Context object for machine code objects.
Definition: MCContext.h:63
void EmitDTPRel64Value(const MCExpr *Value) override
Emit the expression Value into the output as a dtprel (64-bit DTP relative) value.
void emitFill(const MCExpr &NumBytes, uint64_t FillValue, SMLoc Loc=SMLoc()) override
Emit Size bytes worth of the value specified by FillValue.
void EmitFileDirective(StringRef Filename) override
Switch to a new logical file.
Streaming object file generation interface.
MCAssembler * getAssemblerPtr() override
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
void EmitDTPRel32Value(const MCExpr *Value) override
Emit the expression Value into the output as a dtprel (32-bit DTP relative) value.
Instances of this class represent a single low-level machine instruction.
Definition: MCInst.h:161
void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo, unsigned Size) override
Emit the absolute difference between two symbols if possible.
void EmitULEB128Value(const MCExpr *Value) override
Streaming machine code generation interface.
Definition: MCStreamer.h:183
void EmitLabel(MCSymbol *Symbol, SMLoc Loc=SMLoc()) override
Emit a label for Symbol into the current section.
void visitUsedSymbol(const MCSymbol &Sym) override
void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line, unsigned Column, bool PrologueEnd, bool IsStmt, StringRef FileName, SMLoc Loc) override
This implements the CodeView &#39;.cv_loc&#39; assembler directive.
void EmitSLEB128Value(const MCExpr *Value) override
void insert(MCFragment *F)
void EmitCodePaddingBasicBlockEnd(const MCCodePaddingContext &Context) override
void EmitAddrsigSym(const MCSymbol *Sym) override
void EmitCodeAlignment(unsigned ByteAlignment, unsigned MaxBytesToEmit=0) override
Emit nops until the byte alignment ByteAlignment is reached.
MCAssembler & getAssembler()
void EmitFrames(MCAsmBackend *MAB)
void emitValueToOffset(const MCExpr *Offset, unsigned char Value, SMLoc Loc) override
Emit some number of copies of Value until the byte offset Offset is reached.
void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value=0, unsigned ValueSize=1, unsigned MaxBytesToEmit=0) override
Emit some number of copies of Value until the byte alignment ByteAlignment is reached.
MCPaddingFragment * getOrCreatePaddingFragment()
Iterator for intrusive lists based on ilist_node.
void EmitCFISections(bool EH, bool Debug) override
void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, const MCSymbol *Label)
void ChangeSection(MCSection *Section, const MCExpr *Subsection) override
Update streamer for a new active section.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:847
void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin, const MCSymbol *End) override
This implements the CodeView &#39;.cv_linetable&#39; assembler directive.
void EmitBundleAlignMode(unsigned AlignPow2) override
Set the bundle alignment mode from now on in the section.
MCSection * getCurrentSectionOnly() const
Definition: MCStreamer.h:340
void EmitTPRel32Value(const MCExpr *Value) override
Emit the expression Value into the output as a tprel (32-bit TP relative) value.
MCDataFragment * getOrCreateDataFragment(const MCSubtargetInfo *STI=nullptr)
Get a data fragment to write into, creating a new one if the current fragment is not a data fragment...
iterator insert(iterator where, pointer New)
Definition: ilist.h:228
void EmitBundleUnlock() override
Ends a bundle-locked group.
void FinishImpl() override
Streamer specific finalization.
void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override
Emit an assignment of Value to Symbol.
bool isIntegratedAssemblerRequired() const override
Object streamers require the integrated assembler.
void reset() override
state management
Generic base class for all target subtargets.
uint32_t Size
Definition: Profile.cpp:47
void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc=SMLoc()) override
Emit the expression Value into the output as a native integer of the given Size bytes.
void emitFill(uint64_t NumBytes, uint8_t FillValue)
Emit NumBytes bytes worth of the value specified by FillValue.
Definition: MCStreamer.cpp:184
void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, unsigned Column, unsigned Flags, unsigned Isa, unsigned Discriminator, StringRef FileName) override
This implements the DWARF2 &#39;.loc fileno lineno ...&#39; assembler directive.
void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId, unsigned SourceFileId, unsigned SourceLineNum, const MCSymbol *FnStartSym, const MCSymbol *FnEndSym) override
This implements the CodeView &#39;.cv_inline_linetable&#39; assembler directive.
MCFragment * getCurrentFragment() const
Fragment for data and encoded instructions.
Definition: MCFragment.h:242
MCObjectStreamer(MCContext &Context, std::unique_ptr< MCAsmBackend > TAB, std::unique_ptr< MCObjectWriter > OW, std::unique_ptr< MCCodeEmitter > Emitter)
LLVM Value Representation.
Definition: Value.h:73
Generic interface to target specific assembler backends.
Definition: MCAsmBackend.h:42
static cl::opt< bool, true > Debug("debug", cl::desc("Enable debug output"), cl::Hidden, cl::location(DebugFlag))
void EmitGPRel32Value(const MCExpr *Value) override
Emit the expression Value into the output as a gprel32 (32-bit GP relative) value.
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
void EmitCVFileChecksumsDirective() override
This implements the CodeView &#39;.cv_filechecksums&#39; assembler directive.
Represents a location in source code.
Definition: SMLoc.h:24
void setParent(MCSection *Value)
Definition: MCFragment.h:100
void emitAbsoluteSymbolDiffAsULEB128(const MCSymbol *Hi, const MCSymbol *Lo) override
Emit the absolute difference between two symbols encoded with ULEB128.
MCSection::FragmentListType & getFragmentList()
Definition: MCSection.h:150
void EmitGPRel64Value(const MCExpr *Value) override
Emit the expression Value into the output as a gprel64 (64-bit GP relative) value.
void EmitTPRel64Value(const MCExpr *Value) override
Emit the expression Value into the output as a tprel (64-bit TP relative) value.
void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI, bool=false) override
Emit the given Instruction into the current section.