LLVM  7.0.0svn
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  MCAssembler &getAssembler() { return *Assembler; }
94  MCAssembler *getAssemblerPtr() override;
95  /// \name MCStreamer Interface
96  /// @{
97 
98  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
99  virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F);
100  void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
101  void EmitValueImpl(const MCExpr *Value, unsigned Size,
102  SMLoc Loc = SMLoc()) override;
103  void EmitULEB128Value(const MCExpr *Value) override;
104  void EmitSLEB128Value(const MCExpr *Value) override;
105  void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
106  void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
107  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
108  bool = false) override;
109 
110  /// Emit an instruction to a special fragment, because this instruction
111  /// can change its size during relaxation.
112  virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &);
113 
114  void EmitBundleAlignMode(unsigned AlignPow2) override;
115  void EmitBundleLock(bool AlignToEnd) override;
116  void EmitBundleUnlock() override;
117  void EmitBytes(StringRef Data) override;
118  void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
119  unsigned ValueSize = 1,
120  unsigned MaxBytesToEmit = 0) override;
121  void EmitCodeAlignment(unsigned ByteAlignment,
122  unsigned MaxBytesToEmit = 0) override;
123  void emitValueToOffset(const MCExpr *Offset, unsigned char Value,
124  SMLoc Loc) override;
125  void
126  EmitCodePaddingBasicBlockStart(const MCCodePaddingContext &Context) override;
127  void
128  EmitCodePaddingBasicBlockEnd(const MCCodePaddingContext &Context) override;
129  void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
130  unsigned Column, unsigned Flags,
131  unsigned Isa, unsigned Discriminator,
132  StringRef FileName) override;
133  void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
134  const MCSymbol *Label,
135  unsigned PointerSize);
136  void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
137  const MCSymbol *Label);
138  void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line,
139  unsigned Column, bool PrologueEnd, bool IsStmt,
140  StringRef FileName, SMLoc Loc) override;
141  void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin,
142  const MCSymbol *End) override;
143  void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
144  unsigned SourceFileId,
145  unsigned SourceLineNum,
146  const MCSymbol *FnStartSym,
147  const MCSymbol *FnEndSym) override;
149  ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
150  StringRef FixedSizePortion) override;
151  void EmitCVStringTableDirective() override;
152  void EmitCVFileChecksumsDirective() override;
153  void EmitCVFileChecksumOffsetDirective(unsigned FileNo) override;
154  void EmitDTPRel32Value(const MCExpr *Value) override;
155  void EmitDTPRel64Value(const MCExpr *Value) override;
156  void EmitTPRel32Value(const MCExpr *Value) override;
157  void EmitTPRel64Value(const MCExpr *Value) override;
158  void EmitGPRel32Value(const MCExpr *Value) override;
159  void EmitGPRel64Value(const MCExpr *Value) override;
160  bool EmitRelocDirective(const MCExpr &Offset, StringRef Name,
161  const MCExpr *Expr, SMLoc Loc,
162  const MCSubtargetInfo &STI) override;
163  using MCStreamer::emitFill;
164  void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
165  SMLoc Loc = SMLoc()) override;
166  void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
167  SMLoc Loc = SMLoc()) override;
168  void EmitFileDirective(StringRef Filename) override;
169 
170  void FinishImpl() override;
171 
172  /// Emit the absolute difference between two symbols if possible.
173  ///
174  /// Emit the absolute difference between \c Hi and \c Lo, as long as we can
175  /// compute it. Currently, that requires that both symbols are in the same
176  /// data fragment. Otherwise, do nothing and return \c false.
177  ///
178  /// \pre Offset of \c Hi is greater than the offset \c Lo.
179  void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
180  unsigned Size) override;
181 
183  const MCSymbol *Lo) override;
184 
185  bool mayHaveInstructions(MCSection &Sec) const override;
186 };
187 
188 } // end namespace llvm
189 
190 #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:340
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 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 EmitCodeAlignment(unsigned ByteAlignment, unsigned MaxBytesToEmit=0) override
Emit nops until the byte alignment ByteAlignment is reached.
MCAssembler & getAssembler()
static const unsigned End
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:861
void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin, const MCSymbol *End) override
This implements the CodeView &#39;.cv_linetable&#39; assembler directive.
void flushPendingLabels(MCFragment *F, uint64_t FOffset=0)
If any labels have been emitted but not assigned fragments, ensure that they get assigned, either to F if possible or to a new data fragment.
void EmitBundleAlignMode(unsigned AlignPow2) override
Set the bundle alignment mode from now on in the section.
MCSection * getCurrentSectionOnly() const
Definition: MCStreamer.h:337
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.
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:241
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
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
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:143
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.