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  struct PendingMCFixup {
43  const MCSymbol *Sym;
44  MCFixup Fixup;
45  MCDataFragment *DF;
46  PendingMCFixup(const MCSymbol *McSym, MCDataFragment *F, MCFixup McFixup)
47  : Sym(McSym), Fixup(McFixup), DF(F) {}
48  };
49  SmallVector<PendingMCFixup, 2> PendingFixups;
50 
51  virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0;
52  void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
53  void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
54  MCSymbol *EmitCFILabel() override;
55  void EmitInstructionImpl(const MCInst &Inst, const MCSubtargetInfo &STI);
56  void resolvePendingFixups();
57 
58 protected:
59  MCObjectStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
60  std::unique_ptr<MCObjectWriter> OW,
61  std::unique_ptr<MCCodeEmitter> Emitter);
63 
64 public:
65  /// state management
66  void reset() override;
67 
68  /// Object streamers require the integrated assembler.
69  bool isIntegratedAssemblerRequired() const override { return true; }
70 
71  void EmitFrames(MCAsmBackend *MAB);
72  void EmitCFISections(bool EH, bool Debug) override;
73 
75 
76  void insert(MCFragment *F) {
78  MCSection *CurSection = getCurrentSectionOnly();
79  CurSection->getFragmentList().insert(CurInsertionPoint, F);
80  F->setParent(CurSection);
81  }
82 
83  /// Get a data fragment to write into, creating a new one if the current
84  /// fragment is not a data fragment.
85  /// Optionally a \p STI can be passed in so that a new fragment is created
86  /// if the Subtarget differs from the current fragment.
89 
90 protected:
91  bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection);
92 
93  /// If any labels have been emitted but not assigned fragments, ensure that
94  /// they get assigned, either to F if possible or to a new data fragment.
95  /// Optionally, it is also possible to provide an offset \p FOffset, which
96  /// will be used as a symbol offset within the fragment.
97  void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0);
98 
99 public:
100  void visitUsedSymbol(const MCSymbol &Sym) override;
101 
102  /// Create a dummy fragment to assign any pending labels.
104 
105  MCAssembler &getAssembler() { return *Assembler; }
106  MCAssembler *getAssemblerPtr() override;
107  /// \name MCStreamer Interface
108  /// @{
109 
110  void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
111  virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F);
112  void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
113  void EmitValueImpl(const MCExpr *Value, unsigned Size,
114  SMLoc Loc = SMLoc()) override;
115  void EmitULEB128Value(const MCExpr *Value) override;
116  void EmitSLEB128Value(const MCExpr *Value) override;
117  void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
118  void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
119  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
120  bool = false) override;
121 
122  /// Emit an instruction to a special fragment, because this instruction
123  /// can change its size during relaxation.
124  virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &);
125 
126  void EmitBundleAlignMode(unsigned AlignPow2) override;
127  void EmitBundleLock(bool AlignToEnd) override;
128  void EmitBundleUnlock() override;
129  void EmitBytes(StringRef Data) override;
130  void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
131  unsigned ValueSize = 1,
132  unsigned MaxBytesToEmit = 0) override;
133  void EmitCodeAlignment(unsigned ByteAlignment,
134  unsigned MaxBytesToEmit = 0) override;
135  void emitValueToOffset(const MCExpr *Offset, unsigned char Value,
136  SMLoc Loc) override;
137  void
138  EmitCodePaddingBasicBlockStart(const MCCodePaddingContext &Context) override;
139  void
140  EmitCodePaddingBasicBlockEnd(const MCCodePaddingContext &Context) override;
141  void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
142  unsigned Column, unsigned Flags,
143  unsigned Isa, unsigned Discriminator,
144  StringRef FileName) override;
145  void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
146  const MCSymbol *Label,
147  unsigned PointerSize);
148  void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
149  const MCSymbol *Label);
150  void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line,
151  unsigned Column, bool PrologueEnd, bool IsStmt,
152  StringRef FileName, SMLoc Loc) override;
153  void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin,
154  const MCSymbol *End) override;
155  void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
156  unsigned SourceFileId,
157  unsigned SourceLineNum,
158  const MCSymbol *FnStartSym,
159  const MCSymbol *FnEndSym) override;
161  ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
162  StringRef FixedSizePortion) override;
163  void EmitCVStringTableDirective() override;
164  void EmitCVFileChecksumsDirective() override;
165  void EmitCVFileChecksumOffsetDirective(unsigned FileNo) override;
166  void EmitDTPRel32Value(const MCExpr *Value) override;
167  void EmitDTPRel64Value(const MCExpr *Value) override;
168  void EmitTPRel32Value(const MCExpr *Value) override;
169  void EmitTPRel64Value(const MCExpr *Value) override;
170  void EmitGPRel32Value(const MCExpr *Value) override;
171  void EmitGPRel64Value(const MCExpr *Value) override;
172  bool EmitRelocDirective(const MCExpr &Offset, StringRef Name,
173  const MCExpr *Expr, SMLoc Loc,
174  const MCSubtargetInfo &STI) override;
175  using MCStreamer::emitFill;
176  void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
177  SMLoc Loc = SMLoc()) override;
178  void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
179  SMLoc Loc = SMLoc()) override;
180  void EmitFileDirective(StringRef Filename) override;
181 
182  void EmitAddrsig() override;
183  void EmitAddrsigSym(const MCSymbol *Sym) override;
184 
185  void FinishImpl() override;
186 
187  /// Emit the absolute difference between two symbols if possible.
188  ///
189  /// Emit the absolute difference between \c Hi and \c Lo, as long as we can
190  /// compute it. Currently, that requires that both symbols are in the same
191  /// data fragment and that the target has not specified that diff expressions
192  /// require relocations to be emitted. Otherwise, do nothing and return
193  /// \c false.
194  ///
195  /// \pre Offset of \c Hi is greater than the offset \c Lo.
196  void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
197  unsigned Size) override;
198 
200  const MCSymbol *Lo) override;
201 
202  bool mayHaveInstructions(MCSection &Sec) const override;
203 };
204 
205 } // end namespace llvm
206 
207 #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
This class represents lattice values for constants.
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.
Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction)...
Definition: MCFixup.h:74
amdgpu Simplify well known AMD library false Value Value const Twine & Name
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:188
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.
PowerPC TLS Dynamic Call Fixup
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:345
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:196
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.