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MCStreamer.h
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1 //===- MCStreamer.h - High-level Streaming Machine Code Output --*- 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 // This file declares the MCStreamer class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_MC_MCSTREAMER_H
15 #define LLVM_MC_MCSTREAMER_H
16 
17 #include "llvm/ADT/ArrayRef.h"
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/MC/MCDirectives.h"
22 #include "llvm/MC/MCDwarf.h"
24 #include "llvm/MC/MCSymbol.h"
25 #include "llvm/MC/MCWinEH.h"
26 #include "llvm/Support/SMLoc.h"
28 #include <cassert>
29 #include <cstdint>
30 #include <memory>
31 #include <string>
32 #include <utility>
33 #include <vector>
34 
35 namespace llvm {
36 
37 class AssemblerConstantPools;
38 class formatted_raw_ostream;
39 class MCAsmBackend;
40 class MCCodeEmitter;
41 class MCContext;
42 class MCExpr;
43 class MCInst;
44 class MCInstPrinter;
45 class MCSection;
46 class MCStreamer;
47 class MCSymbolRefExpr;
48 class MCSubtargetInfo;
49 class raw_ostream;
50 class Twine;
51 
52 using MCSectionSubPair = std::pair<MCSection *, const MCExpr *>;
53 
54 /// Target specific streamer interface. This is used so that targets can
55 /// implement support for target specific assembly directives.
56 ///
57 /// If target foo wants to use this, it should implement 3 classes:
58 /// * FooTargetStreamer : public MCTargetStreamer
59 /// * FooTargetAsmStreamer : public FooTargetStreamer
60 /// * FooTargetELFStreamer : public FooTargetStreamer
61 ///
62 /// FooTargetStreamer should have a pure virtual method for each directive. For
63 /// example, for a ".bar symbol_name" directive, it should have
64 /// virtual emitBar(const MCSymbol &Symbol) = 0;
65 ///
66 /// The FooTargetAsmStreamer and FooTargetELFStreamer classes implement the
67 /// method. The assembly streamer just prints ".bar symbol_name". The object
68 /// streamer does whatever is needed to implement .bar in the object file.
69 ///
70 /// In the assembly printer and parser the target streamer can be used by
71 /// calling getTargetStreamer and casting it to FooTargetStreamer:
72 ///
73 /// MCTargetStreamer &TS = OutStreamer.getTargetStreamer();
74 /// FooTargetStreamer &ATS = static_cast<FooTargetStreamer &>(TS);
75 ///
76 /// The base classes FooTargetAsmStreamer and FooTargetELFStreamer should
77 /// *never* be treated differently. Callers should always talk to a
78 /// FooTargetStreamer.
80 protected:
82 
83 public:
85  virtual ~MCTargetStreamer();
86 
88 
89  // Allow a target to add behavior to the EmitLabel of MCStreamer.
90  virtual void emitLabel(MCSymbol *Symbol);
91  // Allow a target to add behavior to the emitAssignment of MCStreamer.
92  virtual void emitAssignment(MCSymbol *Symbol, const MCExpr *Value);
93 
94  virtual void prettyPrintAsm(MCInstPrinter &InstPrinter, raw_ostream &OS,
95  const MCInst &Inst, const MCSubtargetInfo &STI);
96 
97  virtual void finish();
98 };
99 
100 // FIXME: declared here because it is used from
101 // lib/CodeGen/AsmPrinter/ARMException.cpp.
103 public:
105  ~ARMTargetStreamer() override;
106 
107  virtual void emitFnStart();
108  virtual void emitFnEnd();
109  virtual void emitCantUnwind();
110  virtual void emitPersonality(const MCSymbol *Personality);
111  virtual void emitPersonalityIndex(unsigned Index);
112  virtual void emitHandlerData();
113  virtual void emitSetFP(unsigned FpReg, unsigned SpReg,
114  int64_t Offset = 0);
115  virtual void emitMovSP(unsigned Reg, int64_t Offset = 0);
116  virtual void emitPad(int64_t Offset);
117  virtual void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
118  bool isVector);
119  virtual void emitUnwindRaw(int64_t StackOffset,
120  const SmallVectorImpl<uint8_t> &Opcodes);
121 
122  virtual void switchVendor(StringRef Vendor);
123  virtual void emitAttribute(unsigned Attribute, unsigned Value);
124  virtual void emitTextAttribute(unsigned Attribute, StringRef String);
125  virtual void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
126  StringRef StringValue = "");
127  virtual void emitFPU(unsigned FPU);
128  virtual void emitArch(ARM::ArchKind Arch);
129  virtual void emitArchExtension(unsigned ArchExt);
130  virtual void emitObjectArch(ARM::ArchKind Arch);
131  void emitTargetAttributes(const MCSubtargetInfo &STI);
132  virtual void finishAttributeSection();
133  virtual void emitInst(uint32_t Inst, char Suffix = '\0');
134 
135  virtual void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE);
136 
137  virtual void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value);
138 
139  void finish() override;
140 
141  /// Reset any state between object emissions, i.e. the equivalent of
142  /// MCStreamer's reset method.
143  virtual void reset();
144 
145  /// Callback used to implement the ldr= pseudo.
146  /// Add a new entry to the constant pool for the current section and return an
147  /// MCExpr that can be used to refer to the constant pool location.
148  const MCExpr *addConstantPoolEntry(const MCExpr *, SMLoc Loc);
149 
150  /// Callback used to implemnt the .ltorg directive.
151  /// Emit contents of constant pool for the current section.
152  void emitCurrentConstantPool();
153 
154 private:
155  std::unique_ptr<AssemblerConstantPools> ConstantPools;
156 };
157 
158 /// \brief Streaming machine code generation interface.
159 ///
160 /// This interface is intended to provide a programatic interface that is very
161 /// similar to the level that an assembler .s file provides. It has callbacks
162 /// to emit bytes, handle directives, etc. The implementation of this interface
163 /// retains state to know what the current section is etc.
164 ///
165 /// There are multiple implementations of this interface: one for writing out
166 /// a .s file, and implementations that write out .o files of various formats.
167 ///
168 class MCStreamer {
170  std::unique_ptr<MCTargetStreamer> TargetStreamer;
171 
172  std::vector<MCDwarfFrameInfo> DwarfFrameInfos;
173  MCDwarfFrameInfo *getCurrentDwarfFrameInfo();
174 
175  /// Similar to DwarfFrameInfos, but for SEH unwind info. Chained frames may
176  /// refer to each other, so use std::unique_ptr to provide pointer stability.
177  std::vector<std::unique_ptr<WinEH::FrameInfo>> WinFrameInfos;
178 
179  WinEH::FrameInfo *CurrentWinFrameInfo;
180 
181  /// Retreive the current frame info if one is available and it is not yet
182  /// closed. Otherwise, issue an error and return null.
183  WinEH::FrameInfo *EnsureValidWinFrameInfo(SMLoc Loc);
184 
185  /// \brief Tracks an index to represent the order a symbol was emitted in.
186  /// Zero means we did not emit that symbol.
188 
189  /// \brief This is stack of current and previous section values saved by
190  /// PushSection.
192 
193  /// The next unique ID to use when creating a WinCFI-related section (.pdata
194  /// or .xdata). This ID ensures that we have a one-to-one mapping from
195  /// code section to unwind info section, which MSVC's incremental linker
196  /// requires.
197  unsigned NextWinCFIID = 0;
198 
199 protected:
200  MCStreamer(MCContext &Ctx);
201 
202  virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame);
203  virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &CurFrame);
204 
205  /// When emitting an object file, create and emit a real label. When emitting
206  /// textual assembly, this should do nothing to avoid polluting our output.
207  virtual MCSymbol *EmitCFILabel();
208 
210  return CurrentWinFrameInfo;
211  }
212 
213  virtual void EmitWindowsUnwindTables();
214 
215  virtual void EmitRawTextImpl(StringRef String);
216 
217 public:
218  MCStreamer(const MCStreamer &) = delete;
219  MCStreamer &operator=(const MCStreamer &) = delete;
220  virtual ~MCStreamer();
221 
222  void visitUsedExpr(const MCExpr &Expr);
223  virtual void visitUsedSymbol(const MCSymbol &Sym);
224 
226  TargetStreamer.reset(TS);
227  }
228 
229  /// State management
230  ///
231  virtual void reset();
232 
233  MCContext &getContext() const { return Context; }
234 
236  return TargetStreamer.get();
237  }
238 
239  unsigned getNumFrameInfos() { return DwarfFrameInfos.size(); }
241  return DwarfFrameInfos;
242  }
243 
244  bool hasUnfinishedDwarfFrameInfo();
245 
246  unsigned getNumWinFrameInfos() { return WinFrameInfos.size(); }
248  return WinFrameInfos;
249  }
250 
251  void generateCompactUnwindEncodings(MCAsmBackend *MAB);
252 
253  /// \name Assembly File Formatting.
254  /// @{
255 
256  /// \brief Return true if this streamer supports verbose assembly and if it is
257  /// enabled.
258  virtual bool isVerboseAsm() const { return false; }
259 
260  /// \brief Return true if this asm streamer supports emitting unformatted text
261  /// to the .s file with EmitRawText.
262  virtual bool hasRawTextSupport() const { return false; }
263 
264  /// \brief Is the integrated assembler required for this streamer to function
265  /// correctly?
266  virtual bool isIntegratedAssemblerRequired() const { return false; }
267 
268  /// \brief Add a textual comment.
269  ///
270  /// Typically for comments that can be emitted to the generated .s
271  /// file if applicable as a QoI issue to make the output of the compiler
272  /// more readable. This only affects the MCAsmStreamer, and only when
273  /// verbose assembly output is enabled.
274  ///
275  /// If the comment includes embedded \n's, they will each get the comment
276  /// prefix as appropriate. The added comment should not end with a \n.
277  /// By default, each comment is terminated with an end of line, i.e. the
278  /// EOL param is set to true by default. If one prefers not to end the
279  /// comment with a new line then the EOL param should be passed
280  /// with a false value.
281  virtual void AddComment(const Twine &T, bool EOL = true) {}
282 
283  /// \brief Return a raw_ostream that comments can be written to. Unlike
284  /// AddComment, you are required to terminate comments with \n if you use this
285  /// method.
286  virtual raw_ostream &GetCommentOS();
287 
288  /// \brief Print T and prefix it with the comment string (normally #) and
289  /// optionally a tab. This prints the comment immediately, not at the end of
290  /// the current line. It is basically a safe version of EmitRawText: since it
291  /// only prints comments, the object streamer ignores it instead of asserting.
292  virtual void emitRawComment(const Twine &T, bool TabPrefix = true);
293 
294  /// \brief Add explicit comment T. T is required to be a valid
295  /// comment in the output and does not need to be escaped.
296  virtual void addExplicitComment(const Twine &T);
297 
298  /// \brief Emit added explicit comments.
299  virtual void emitExplicitComments();
300 
301  /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
302  virtual void AddBlankLine() {}
303 
304  /// @}
305 
306  /// \name Symbol & Section Management
307  /// @{
308 
309  /// \brief Return the current section that the streamer is emitting code to.
311  if (!SectionStack.empty())
312  return SectionStack.back().first;
313  return MCSectionSubPair();
314  }
315  MCSection *getCurrentSectionOnly() const { return getCurrentSection().first; }
316 
317  /// \brief Return the previous section that the streamer is emitting code to.
319  if (!SectionStack.empty())
320  return SectionStack.back().second;
321  return MCSectionSubPair();
322  }
323 
324  /// \brief Returns an index to represent the order a symbol was emitted in.
325  /// (zero if we did not emit that symbol)
326  unsigned GetSymbolOrder(const MCSymbol *Sym) const {
327  return SymbolOrdering.lookup(Sym);
328  }
329 
330  /// \brief Update streamer for a new active section.
331  ///
332  /// This is called by PopSection and SwitchSection, if the current
333  /// section changes.
334  virtual void ChangeSection(MCSection *, const MCExpr *);
335 
336  /// \brief Save the current and previous section on the section stack.
337  void PushSection() {
338  SectionStack.push_back(
339  std::make_pair(getCurrentSection(), getPreviousSection()));
340  }
341 
342  /// \brief Restore the current and previous section from the section stack.
343  /// Calls ChangeSection as needed.
344  ///
345  /// Returns false if the stack was empty.
346  bool PopSection() {
347  if (SectionStack.size() <= 1)
348  return false;
349  auto I = SectionStack.end();
350  --I;
351  MCSectionSubPair OldSection = I->first;
352  --I;
353  MCSectionSubPair NewSection = I->first;
354 
355  if (OldSection != NewSection)
356  ChangeSection(NewSection.first, NewSection.second);
357  SectionStack.pop_back();
358  return true;
359  }
360 
361  bool SubSection(const MCExpr *Subsection) {
362  if (SectionStack.empty())
363  return false;
364 
365  SwitchSection(SectionStack.back().first.first, Subsection);
366  return true;
367  }
368 
369  /// Set the current section where code is being emitted to \p Section. This
370  /// is required to update CurSection.
371  ///
372  /// This corresponds to assembler directives like .section, .text, etc.
373  virtual void SwitchSection(MCSection *Section,
374  const MCExpr *Subsection = nullptr);
375 
376  /// \brief Set the current section where code is being emitted to \p Section.
377  /// This is required to update CurSection. This version does not call
378  /// ChangeSection.
380  const MCExpr *Subsection = nullptr) {
381  assert(Section && "Cannot switch to a null section!");
382  MCSectionSubPair curSection = SectionStack.back().first;
383  SectionStack.back().second = curSection;
384  if (MCSectionSubPair(Section, Subsection) != curSection)
385  SectionStack.back().first = MCSectionSubPair(Section, Subsection);
386  }
387 
388  /// \brief Create the default sections and set the initial one.
389  virtual void InitSections(bool NoExecStack);
390 
391  MCSymbol *endSection(MCSection *Section);
392 
393  /// \brief Sets the symbol's section.
394  ///
395  /// Each emitted symbol will be tracked in the ordering table,
396  /// so we can sort on them later.
397  void AssignFragment(MCSymbol *Symbol, MCFragment *Fragment);
398 
399  /// \brief Emit a label for \p Symbol into the current section.
400  ///
401  /// This corresponds to an assembler statement such as:
402  /// foo:
403  ///
404  /// \param Symbol - The symbol to emit. A given symbol should only be
405  /// emitted as a label once, and symbols emitted as a label should never be
406  /// used in an assignment.
407  // FIXME: These emission are non-const because we mutate the symbol to
408  // add the section we're emitting it to later.
409  virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc());
410 
411  virtual void EmitEHSymAttributes(const MCSymbol *Symbol, MCSymbol *EHSymbol);
412 
413  /// \brief Note in the output the specified \p Flag.
414  virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
415 
416  /// \brief Emit the given list \p Options of strings as linker
417  /// options into the output.
419 
420  /// \brief Note in the output the specified region \p Kind.
422 
423  /// \brief Specify the MachO minimum deployment target version.
424  virtual void EmitVersionMin(MCVersionMinType, unsigned Major, unsigned Minor,
425  unsigned Update) {}
426 
427  /// \brief Note in the output that the specified \p Func is a Thumb mode
428  /// function (ARM target only).
429  virtual void EmitThumbFunc(MCSymbol *Func);
430 
431  /// \brief Emit an assignment of \p Value to \p Symbol.
432  ///
433  /// This corresponds to an assembler statement such as:
434  /// symbol = value
435  ///
436  /// The assignment generates no code, but has the side effect of binding the
437  /// value in the current context. For the assembly streamer, this prints the
438  /// binding into the .s file.
439  ///
440  /// \param Symbol - The symbol being assigned to.
441  /// \param Value - The value for the symbol.
442  virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
443 
444  /// \brief Emit an weak reference from \p Alias to \p Symbol.
445  ///
446  /// This corresponds to an assembler statement such as:
447  /// .weakref alias, symbol
448  ///
449  /// \param Alias - The alias that is being created.
450  /// \param Symbol - The symbol being aliased.
451  virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
452 
453  /// \brief Add the given \p Attribute to \p Symbol.
454  virtual bool EmitSymbolAttribute(MCSymbol *Symbol,
455  MCSymbolAttr Attribute) = 0;
456 
457  /// \brief Set the \p DescValue for the \p Symbol.
458  ///
459  /// \param Symbol - The symbol to have its n_desc field set.
460  /// \param DescValue - The value to set into the n_desc field.
461  virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
462 
463  /// \brief Start emitting COFF symbol definition
464  ///
465  /// \param Symbol - The symbol to have its External & Type fields set.
466  virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol);
467 
468  /// \brief Emit the storage class of the symbol.
469  ///
470  /// \param StorageClass - The storage class the symbol should have.
471  virtual void EmitCOFFSymbolStorageClass(int StorageClass);
472 
473  /// \brief Emit the type of the symbol.
474  ///
475  /// \param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
476  virtual void EmitCOFFSymbolType(int Type);
477 
478  /// \brief Marks the end of the symbol definition.
479  virtual void EndCOFFSymbolDef();
480 
481  virtual void EmitCOFFSafeSEH(MCSymbol const *Symbol);
482 
483  /// \brief Emits a COFF section index.
484  ///
485  /// \param Symbol - Symbol the section number relocation should point to.
486  virtual void EmitCOFFSectionIndex(MCSymbol const *Symbol);
487 
488  /// \brief Emits a COFF section relative relocation.
489  ///
490  /// \param Symbol - Symbol the section relative relocation should point to.
491  virtual void EmitCOFFSecRel32(MCSymbol const *Symbol, uint64_t Offset);
492 
493  /// \brief Emit an ELF .size directive.
494  ///
495  /// This corresponds to an assembler statement such as:
496  /// .size symbol, expression
497  virtual void emitELFSize(MCSymbol *Symbol, const MCExpr *Value);
498 
499  /// \brief Emit an ELF .symver directive.
500  ///
501  /// This corresponds to an assembler statement such as:
502  /// .symver _start, foo@@SOME_VERSION
503  /// \param Alias - The versioned alias (i.e. "foo@@SOME_VERSION")
504  /// \param Aliasee - The aliased symbol (i.e. "_start")
505  virtual void emitELFSymverDirective(MCSymbol *Alias, const MCSymbol *Aliasee);
506 
507  /// \brief Emit a Linker Optimization Hint (LOH) directive.
508  /// \param Args - Arguments of the LOH.
509  virtual void EmitLOHDirective(MCLOHType Kind, const MCLOHArgs &Args) {}
510 
511  /// \brief Emit a common symbol.
512  ///
513  /// \param Symbol - The common symbol to emit.
514  /// \param Size - The size of the common symbol.
515  /// \param ByteAlignment - The alignment of the symbol if
516  /// non-zero. This must be a power of 2.
517  virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
518  unsigned ByteAlignment) = 0;
519 
520  /// \brief Emit a local common (.lcomm) symbol.
521  ///
522  /// \param Symbol - The common symbol to emit.
523  /// \param Size - The size of the common symbol.
524  /// \param ByteAlignment - The alignment of the common symbol in bytes.
525  virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
526  unsigned ByteAlignment);
527 
528  /// \brief Emit the zerofill section and an optional symbol.
529  ///
530  /// \param Section - The zerofill section to create and or to put the symbol
531  /// \param Symbol - The zerofill symbol to emit, if non-NULL.
532  /// \param Size - The size of the zerofill symbol.
533  /// \param ByteAlignment - The alignment of the zerofill symbol if
534  /// non-zero. This must be a power of 2 on some targets.
535  virtual void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
536  uint64_t Size = 0, unsigned ByteAlignment = 0) = 0;
537 
538  /// \brief Emit a thread local bss (.tbss) symbol.
539  ///
540  /// \param Section - The thread local common section.
541  /// \param Symbol - The thread local common symbol to emit.
542  /// \param Size - The size of the symbol.
543  /// \param ByteAlignment - The alignment of the thread local common symbol
544  /// if non-zero. This must be a power of 2 on some targets.
545  virtual void EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
546  uint64_t Size, unsigned ByteAlignment = 0);
547 
548  /// @}
549  /// \name Generating Data
550  /// @{
551 
552  /// \brief Emit the bytes in \p Data into the output.
553  ///
554  /// This is used to implement assembler directives such as .byte, .ascii,
555  /// etc.
556  virtual void EmitBytes(StringRef Data);
557 
558  /// Functionally identical to EmitBytes. When emitting textual assembly, this
559  /// method uses .byte directives instead of .ascii or .asciz for readability.
560  virtual void EmitBinaryData(StringRef Data);
561 
562  /// \brief Emit the expression \p Value into the output as a native
563  /// integer of the given \p Size bytes.
564  ///
565  /// This is used to implement assembler directives such as .word, .quad,
566  /// etc.
567  ///
568  /// \param Value - The value to emit.
569  /// \param Size - The size of the integer (in bytes) to emit. This must
570  /// match a native machine width.
571  /// \param Loc - The location of the expression for error reporting.
572  virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
573  SMLoc Loc = SMLoc());
574 
575  void EmitValue(const MCExpr *Value, unsigned Size, SMLoc Loc = SMLoc());
576 
577  /// \brief Special case of EmitValue that avoids the client having
578  /// to pass in a MCExpr for constant integers.
579  virtual void EmitIntValue(uint64_t Value, unsigned Size);
580 
581  virtual void EmitULEB128Value(const MCExpr *Value);
582 
583  virtual void EmitSLEB128Value(const MCExpr *Value);
584 
585  /// \brief Special case of EmitULEB128Value that avoids the client having to
586  /// pass in a MCExpr for constant integers.
587  void EmitULEB128IntValue(uint64_t Value);
588 
589  /// \brief Like EmitULEB128Value but pads the output to specific number of
590  /// bytes.
591  void EmitPaddedULEB128IntValue(uint64_t Value, unsigned PadTo);
592 
593  /// \brief Special case of EmitSLEB128Value that avoids the client having to
594  /// pass in a MCExpr for constant integers.
595  void EmitSLEB128IntValue(int64_t Value);
596 
597  /// \brief Special case of EmitValue that avoids the client having to pass in
598  /// a MCExpr for MCSymbols.
599  void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
600  bool IsSectionRelative = false);
601 
602  /// \brief Emit the expression \p Value into the output as a dtprel
603  /// (64-bit DTP relative) value.
604  ///
605  /// This is used to implement assembler directives such as .dtpreldword on
606  /// targets that support them.
607  virtual void EmitDTPRel64Value(const MCExpr *Value);
608 
609  /// \brief Emit the expression \p Value into the output as a dtprel
610  /// (32-bit DTP relative) value.
611  ///
612  /// This is used to implement assembler directives such as .dtprelword on
613  /// targets that support them.
614  virtual void EmitDTPRel32Value(const MCExpr *Value);
615 
616  /// \brief Emit the expression \p Value into the output as a tprel
617  /// (64-bit TP relative) value.
618  ///
619  /// This is used to implement assembler directives such as .tpreldword on
620  /// targets that support them.
621  virtual void EmitTPRel64Value(const MCExpr *Value);
622 
623  /// \brief Emit the expression \p Value into the output as a tprel
624  /// (32-bit TP relative) value.
625  ///
626  /// This is used to implement assembler directives such as .tprelword on
627  /// targets that support them.
628  virtual void EmitTPRel32Value(const MCExpr *Value);
629 
630  /// \brief Emit the expression \p Value into the output as a gprel64 (64-bit
631  /// GP relative) value.
632  ///
633  /// This is used to implement assembler directives such as .gpdword on
634  /// targets that support them.
635  virtual void EmitGPRel64Value(const MCExpr *Value);
636 
637  /// \brief Emit the expression \p Value into the output as a gprel32 (32-bit
638  /// GP relative) value.
639  ///
640  /// This is used to implement assembler directives such as .gprel32 on
641  /// targets that support them.
642  virtual void EmitGPRel32Value(const MCExpr *Value);
643 
644  /// \brief Emit NumBytes bytes worth of the value specified by FillValue.
645  /// This implements directives such as '.space'.
646  virtual void emitFill(uint64_t NumBytes, uint8_t FillValue);
647 
648  /// \brief Emit \p Size bytes worth of the value specified by \p FillValue.
649  ///
650  /// This is used to implement assembler directives such as .space or .skip.
651  ///
652  /// \param NumBytes - The number of bytes to emit.
653  /// \param FillValue - The value to use when filling bytes.
654  /// \param Loc - The location of the expression for error reporting.
655  virtual void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
656  SMLoc Loc = SMLoc());
657 
658  /// \brief Emit \p NumValues copies of \p Size bytes. Each \p Size bytes is
659  /// taken from the lowest order 4 bytes of \p Expr expression.
660  ///
661  /// This is used to implement assembler directives such as .fill.
662  ///
663  /// \param NumValues - The number of copies of \p Size bytes to emit.
664  /// \param Size - The size (in bytes) of each repeated value.
665  /// \param Expr - The expression from which \p Size bytes are used.
666  virtual void emitFill(uint64_t NumValues, int64_t Size, int64_t Expr);
667  virtual void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
668  SMLoc Loc = SMLoc());
669 
670  /// \brief Emit NumBytes worth of zeros.
671  /// This function properly handles data in virtual sections.
672  void EmitZeros(uint64_t NumBytes);
673 
674  /// \brief Emit some number of copies of \p Value until the byte alignment \p
675  /// ByteAlignment is reached.
676  ///
677  /// If the number of bytes need to emit for the alignment is not a multiple
678  /// of \p ValueSize, then the contents of the emitted fill bytes is
679  /// undefined.
680  ///
681  /// This used to implement the .align assembler directive.
682  ///
683  /// \param ByteAlignment - The alignment to reach. This must be a power of
684  /// two on some targets.
685  /// \param Value - The value to use when filling bytes.
686  /// \param ValueSize - The size of the integer (in bytes) to emit for
687  /// \p Value. This must match a native machine width.
688  /// \param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
689  /// the alignment cannot be reached in this many bytes, no bytes are
690  /// emitted.
691  virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
692  unsigned ValueSize = 1,
693  unsigned MaxBytesToEmit = 0);
694 
695  /// \brief Emit nops until the byte alignment \p ByteAlignment is reached.
696  ///
697  /// This used to align code where the alignment bytes may be executed. This
698  /// can emit different bytes for different sizes to optimize execution.
699  ///
700  /// \param ByteAlignment - The alignment to reach. This must be a power of
701  /// two on some targets.
702  /// \param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
703  /// the alignment cannot be reached in this many bytes, no bytes are
704  /// emitted.
705  virtual void EmitCodeAlignment(unsigned ByteAlignment,
706  unsigned MaxBytesToEmit = 0);
707 
708  /// \brief Emit some number of copies of \p Value until the byte offset \p
709  /// Offset is reached.
710  ///
711  /// This is used to implement assembler directives such as .org.
712  ///
713  /// \param Offset - The offset to reach. This may be an expression, but the
714  /// expression must be associated with the current section.
715  /// \param Value - The value to use when filling bytes.
716  virtual void emitValueToOffset(const MCExpr *Offset, unsigned char Value,
717  SMLoc Loc);
718 
719  /// @}
720 
721  /// \brief Switch to a new logical file. This is used to implement the '.file
722  /// "foo.c"' assembler directive.
723  virtual void EmitFileDirective(StringRef Filename);
724 
725  /// \brief Emit the "identifiers" directive. This implements the
726  /// '.ident "version foo"' assembler directive.
727  virtual void EmitIdent(StringRef IdentString) {}
728 
729  /// \brief Associate a filename with a specified logical file number. This
730  /// implements the DWARF2 '.file 4 "foo.c"' assembler directive.
731  virtual unsigned EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
732  StringRef Filename,
733  unsigned CUID = 0);
734 
735  /// \brief This implements the DWARF2 '.loc fileno lineno ...' assembler
736  /// directive.
737  virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
738  unsigned Column, unsigned Flags,
739  unsigned Isa, unsigned Discriminator,
740  StringRef FileName);
741 
742  /// Associate a filename with a specified logical file number, and also
743  /// specify that file's checksum information. This implements the '.cv_file 4
744  /// "foo.c"' assembler directive. Returns true on success.
745  virtual bool EmitCVFileDirective(unsigned FileNo, StringRef Filename,
746  ArrayRef<uint8_t> Checksum,
747  unsigned ChecksumKind);
748 
749  /// \brief Introduces a function id for use with .cv_loc.
750  virtual bool EmitCVFuncIdDirective(unsigned FunctionId);
751 
752  /// \brief Introduces an inline call site id for use with .cv_loc. Includes
753  /// extra information for inline line table generation.
754  virtual bool EmitCVInlineSiteIdDirective(unsigned FunctionId, unsigned IAFunc,
755  unsigned IAFile, unsigned IALine,
756  unsigned IACol, SMLoc Loc);
757 
758  /// \brief This implements the CodeView '.cv_loc' assembler directive.
759  virtual void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo,
760  unsigned Line, unsigned Column,
761  bool PrologueEnd, bool IsStmt,
762  StringRef FileName, SMLoc Loc);
763 
764  /// \brief This implements the CodeView '.cv_linetable' assembler directive.
765  virtual void EmitCVLinetableDirective(unsigned FunctionId,
766  const MCSymbol *FnStart,
767  const MCSymbol *FnEnd);
768 
769  /// \brief This implements the CodeView '.cv_inline_linetable' assembler
770  /// directive.
771  virtual void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
772  unsigned SourceFileId,
773  unsigned SourceLineNum,
774  const MCSymbol *FnStartSym,
775  const MCSymbol *FnEndSym);
776 
777  /// \brief This implements the CodeView '.cv_def_range' assembler
778  /// directive.
779  virtual void EmitCVDefRangeDirective(
780  ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
781  StringRef FixedSizePortion);
782 
783  /// \brief This implements the CodeView '.cv_stringtable' assembler directive.
784  virtual void EmitCVStringTableDirective() {}
785 
786  /// \brief This implements the CodeView '.cv_filechecksums' assembler directive.
788 
789  /// This implements the CodeView '.cv_filechecksumoffset' assembler
790  /// directive.
791  virtual void EmitCVFileChecksumOffsetDirective(unsigned FileNo) {}
792 
793  /// This implements the CodeView '.cv_fpo_data' assembler directive.
794  virtual void EmitCVFPOData(const MCSymbol *ProcSym, SMLoc Loc = {}) {}
795 
796  /// Emit the absolute difference between two symbols.
797  ///
798  /// \pre Offset of \c Hi is greater than the offset \c Lo.
799  virtual void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
800  unsigned Size);
801 
802  virtual MCSymbol *getDwarfLineTableSymbol(unsigned CUID);
803  virtual void EmitCFISections(bool EH, bool Debug);
804  void EmitCFIStartProc(bool IsSimple);
805  void EmitCFIEndProc();
806  virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
807  virtual void EmitCFIDefCfaOffset(int64_t Offset);
808  virtual void EmitCFIDefCfaRegister(int64_t Register);
809  virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
810  virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
811  virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
812  virtual void EmitCFIRememberState();
813  virtual void EmitCFIRestoreState();
814  virtual void EmitCFISameValue(int64_t Register);
815  virtual void EmitCFIRestore(int64_t Register);
816  virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
817  virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
818  virtual void EmitCFIEscape(StringRef Values);
819  virtual void EmitCFIReturnColumn(int64_t Register);
820  virtual void EmitCFIGnuArgsSize(int64_t Size);
821  virtual void EmitCFISignalFrame();
822  virtual void EmitCFIUndefined(int64_t Register);
823  virtual void EmitCFIRegister(int64_t Register1, int64_t Register2);
824  virtual void EmitCFIWindowSave();
825 
826  virtual void EmitWinCFIStartProc(const MCSymbol *Symbol, SMLoc Loc = SMLoc());
827  virtual void EmitWinCFIEndProc(SMLoc Loc = SMLoc());
828  virtual void EmitWinCFIStartChained(SMLoc Loc = SMLoc());
829  virtual void EmitWinCFIEndChained(SMLoc Loc = SMLoc());
830  virtual void EmitWinCFIPushReg(unsigned Register, SMLoc Loc = SMLoc());
831  virtual void EmitWinCFISetFrame(unsigned Register, unsigned Offset,
832  SMLoc Loc = SMLoc());
833  virtual void EmitWinCFIAllocStack(unsigned Size, SMLoc Loc = SMLoc());
834  virtual void EmitWinCFISaveReg(unsigned Register, unsigned Offset,
835  SMLoc Loc = SMLoc());
836  virtual void EmitWinCFISaveXMM(unsigned Register, unsigned Offset,
837  SMLoc Loc = SMLoc());
838  virtual void EmitWinCFIPushFrame(bool Code, SMLoc Loc = SMLoc());
839  virtual void EmitWinCFIEndProlog(SMLoc Loc = SMLoc());
840  virtual void EmitWinEHHandler(const MCSymbol *Sym, bool Unwind, bool Except,
841  SMLoc Loc = SMLoc());
842  virtual void EmitWinEHHandlerData(SMLoc Loc = SMLoc());
843 
844  /// Get the .pdata section used for the given section. Typically the given
845  /// section is either the main .text section or some other COMDAT .text
846  /// section, but it may be any section containing code.
847  MCSection *getAssociatedPDataSection(const MCSection *TextSec);
848 
849  /// Get the .xdata section used for the given section.
850  MCSection *getAssociatedXDataSection(const MCSection *TextSec);
851 
852  virtual void EmitSyntaxDirective();
853 
854  /// \brief Emit a .reloc directive.
855  /// Returns true if the relocation could not be emitted because Name is not
856  /// known.
857  virtual bool EmitRelocDirective(const MCExpr &Offset, StringRef Name,
858  const MCExpr *Expr, SMLoc Loc) {
859  return true;
860  }
861 
862  /// \brief Emit the given \p Instruction into the current section.
863  /// PrintSchedInfo == true then schedul comment should be added to output
864  virtual void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
865  bool PrintSchedInfo = false);
866 
867  /// \brief Set the bundle alignment mode from now on in the section.
868  /// The argument is the power of 2 to which the alignment is set. The
869  /// value 0 means turn the bundle alignment off.
870  virtual void EmitBundleAlignMode(unsigned AlignPow2);
871 
872  /// \brief The following instructions are a bundle-locked group.
873  ///
874  /// \param AlignToEnd - If true, the bundle-locked group will be aligned to
875  /// the end of a bundle.
876  virtual void EmitBundleLock(bool AlignToEnd);
877 
878  /// \brief Ends a bundle-locked group.
879  virtual void EmitBundleUnlock();
880 
881  /// \brief If this file is backed by a assembly streamer, this dumps the
882  /// specified string in the output .s file. This capability is indicated by
883  /// the hasRawTextSupport() predicate. By default this aborts.
884  void EmitRawText(const Twine &String);
885 
886  /// \brief Streamer specific finalization.
887  virtual void FinishImpl();
888  /// \brief Finish emission of machine code.
889  void Finish();
890 
891  virtual bool mayHaveInstructions(MCSection &Sec) const { return true; }
892 };
893 
894 /// Create a dummy machine code streamer, which does nothing. This is useful for
895 /// timing the assembler front end.
897 
898 /// Create a machine code streamer which will print out assembly for the native
899 /// target, suitable for compiling with a native assembler.
900 ///
901 /// \param InstPrint - If given, the instruction printer to use. If not given
902 /// the MCInst representation will be printed. This method takes ownership of
903 /// InstPrint.
904 ///
905 /// \param CE - If given, a code emitter to use to show the instruction
906 /// encoding inline with the assembly. This method takes ownership of \p CE.
907 ///
908 /// \param TAB - If given, a target asm backend to use to show the fixup
909 /// information in conjunction with encoding information. This method takes
910 /// ownership of \p TAB.
911 ///
912 /// \param ShowInst - Whether to show the MCInst representation inline with
913 /// the assembly.
915  std::unique_ptr<formatted_raw_ostream> OS,
916  bool isVerboseAsm, bool useDwarfDirectory,
917  MCInstPrinter *InstPrint, MCCodeEmitter *CE,
918  MCAsmBackend *TAB, bool ShowInst);
919 
920 } // end namespace llvm
921 
922 #endif // LLVM_MC_MCSTREAMER_H
Instances of this class represent a uniqued identifier for a section in the current translation unit...
Definition: MCSection.h:39
unsigned GetSymbolOrder(const MCSymbol *Sym) const
Returns an index to represent the order a symbol was emitted in.
Definition: MCStreamer.h:326
virtual void EmitCVStringTableDirective()
This implements the CodeView &#39;.cv_stringtable&#39; assembler directive.
Definition: MCStreamer.h:784
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
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:136
virtual void AddBlankLine()
AddBlankLine - Emit a blank line to a .s file to pretty it up.
Definition: MCStreamer.h:302
void SwitchSectionNoChange(MCSection *Section, const MCExpr *Subsection=nullptr)
Set the current section where code is being emitted to Section.
Definition: MCStreamer.h:379
Target specific streamer interface.
Definition: MCStreamer.h:79
struct fuzzer::@319 Flags
MCStreamer * createNullStreamer(MCContext &Ctx)
Create a dummy machine code streamer, which does nothing.
void PushSection()
Save the current and previous section on the section stack.
Definition: MCStreamer.h:337
virtual void EmitCVFPOData(const MCSymbol *ProcSym, SMLoc Loc={})
This implements the CodeView &#39;.cv_fpo_data&#39; assembler directive.
Definition: MCStreamer.h:794
MCDataRegionType
Definition: MCDirectives.h:56
COFF::SymbolStorageClass StorageClass
Definition: COFFYAML.cpp:314
MCContext & getContext() const
Definition: MCStreamer.h:233
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
Base class for the full range of assembler expressions which are needed for parsing.
Definition: MCExpr.h:36
Reg
All possible values of the reg field in the ModR/M byte.
Represent a reference to a symbol from inside an expression.
Definition: MCExpr.h:165
virtual void emitLabel(MCSymbol *Symbol)
Definition: MCStreamer.cpp:48
unsigned getNumWinFrameInfos()
Definition: MCStreamer.h:246
ArrayRef< std::unique_ptr< WinEH::FrameInfo > > getWinFrameInfos() const
Definition: MCStreamer.h:247
Context object for machine code objects.
Definition: MCContext.h:59
MCSectionSubPair getPreviousSection() const
Return the previous section that the streamer is emitting code to.
Definition: MCStreamer.h:318
virtual void AddComment(const Twine &T, bool EOL=true)
Add a textual comment.
Definition: MCStreamer.h:281
virtual void EmitCVFileChecksumsDirective()
This implements the CodeView &#39;.cv_filechecksums&#39; assembler directive.
Definition: MCStreamer.h:787
virtual void finish()
Definition: MCStreamer.cpp:50
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:33
Instances of this class represent a single low-level machine instruction.
Definition: MCInst.h:159
virtual bool hasRawTextSupport() const
Return true if this asm streamer supports emitting unformatted text to the .s file with EmitRawText...
Definition: MCStreamer.h:262
Flag
These should be considered private to the implementation of the MCInstrDesc class.
Definition: MCInstrDesc.h:121
virtual void EmitVersionMin(MCVersionMinType, unsigned Major, unsigned Minor, unsigned Update)
Specify the MachO minimum deployment target version.
Definition: MCStreamer.h:424
Streaming machine code generation interface.
Definition: MCStreamer.h:168
WinEH::FrameInfo * getCurrentWinFrameInfo()
Definition: MCStreamer.h:209
MCTargetStreamer * getTargetStreamer()
Definition: MCStreamer.h:235
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
MCStreamer * createAsmStreamer(MCContext &Ctx, std::unique_ptr< formatted_raw_ostream > OS, bool isVerboseAsm, bool useDwarfDirectory, MCInstPrinter *InstPrint, MCCodeEmitter *CE, MCAsmBackend *TAB, bool ShowInst)
Create a machine code streamer which will print out assembly for the native target, suitable for compiling with a native assembler.
MCCodeEmitter - Generic instruction encoding interface.
Definition: MCCodeEmitter.h:22
MCLOHType
Linker Optimization Hint Type.
virtual bool mayHaveInstructions(MCSection &Sec) const
Definition: MCStreamer.h:891
virtual void EmitIdent(StringRef IdentString)
Emit the "identifiers" directive.
Definition: MCStreamer.h:727
bool SubSection(const MCExpr *Subsection)
Definition: MCStreamer.h:361
virtual void EmitDataRegion(MCDataRegionType Kind)
Note in the output the specified region Kind.
Definition: MCStreamer.h:421
MCSectionSubPair getCurrentSection() const
Return the current section that the streamer is emitting code to.
Definition: MCStreamer.h:310
MCStreamer & getStreamer()
Definition: MCStreamer.h:87
std::pair< MCSection *, const MCExpr * > MCSectionSubPair
Definition: MCStreamer.h:52
virtual void EmitLOHDirective(MCLOHType Kind, const MCLOHArgs &Args)
Emit a Linker Optimization Hint (LOH) directive.
Definition: MCStreamer.h:509
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:864
bool isVector(MCInstrInfo const &MCII, MCInst const &MCI)
MCStreamer & Streamer
Definition: MCStreamer.h:81
Promote Memory to Register
Definition: Mem2Reg.cpp:101
virtual void prettyPrintAsm(MCInstPrinter &InstPrinter, raw_ostream &OS, const MCInst &Inst, const MCSubtargetInfo &STI)
Definition: MCStreamer.cpp:829
MCSymbolAttr
Definition: MCDirectives.h:19
MCSection * getCurrentSectionOnly() const
Definition: MCStreamer.h:315
MCTargetStreamer(MCStreamer &S)
Definition: MCStreamer.cpp:41
virtual void EmitCVFileChecksumOffsetDirective(unsigned FileNo)
This implements the CodeView &#39;.cv_filechecksumoffset&#39; assembler directive.
Definition: MCStreamer.h:791
LLVM_ATTRIBUTE_ALWAYS_INLINE iterator end()
Definition: SmallVector.h:120
This is an instance of a target assembly language printer that converts an MCInst to valid target ass...
Definition: MCInstPrinter.h:41
unsigned getNumFrameInfos()
Definition: MCStreamer.h:239
virtual bool EmitRelocDirective(const MCExpr &Offset, StringRef Name, const MCExpr *Expr, SMLoc Loc)
Emit a .reloc directive.
Definition: MCStreamer.h:857
virtual void EmitLinkerOptions(ArrayRef< std::string > Kind)
Emit the given list Options of strings as linker options into the output.
Definition: MCStreamer.h:418
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:61
MCAssemblerFlag
Definition: MCDirectives.h:48
#define I(x, y, z)
Definition: MD5.cpp:58
MCSubtargetInfo - Generic base class for all target subtargets.
ValueT lookup(const_arg_type_t< KeyT > Val) const
lookup - Return the entry for the specified key, or a default constructed value if no such entry exis...
Definition: DenseMap.h:181
const unsigned Kind
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
bool PopSection()
Restore the current and previous section from the section stack.
Definition: MCStreamer.h:346
MCVersionMinType
Definition: MCDirectives.h:64
LLVM Value Representation.
Definition: Value.h:73
Generic interface to target specific assembler backends.
Definition: MCAsmBackend.h:35
ArrayRef< MCDwarfFrameInfo > getDwarfFrameInfos() const
Definition: MCStreamer.h:240
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))
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:49
Represents a location in source code.
Definition: SMLoc.h:24
virtual bool isVerboseAsm() const
Return true if this streamer supports verbose assembly and if it is enabled.
Definition: MCStreamer.h:258
void setTargetStreamer(MCTargetStreamer *TS)
Definition: MCStreamer.h:225
virtual void emitAssignment(MCSymbol *Symbol, const MCExpr *Value)
Definition: MCStreamer.cpp:52
constexpr char Args[]
Key for Kernel::Metadata::mArgs.
virtual bool isIntegratedAssemblerRequired() const
Is the integrated assembler required for this streamer to function correctly?
Definition: MCStreamer.h:266