1 //===- MCStreamer.h - High-level Streaming Machine Code Output --*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file declares the MCStreamer class.
11 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_MC_MCSTREAMER_H
14 #define LLVM_MC_MCSTREAMER_H
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/Optional.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/MC/MCDirectives.h"
22 #include "llvm/MC/MCLinkerOptimizationHint.h"
23 #include "llvm/MC/MCSymbol.h"
24 #include "llvm/MC/MCWinEH.h"
25 #include "llvm/Support/Error.h"
26 #include "llvm/Support/MD5.h"
27 #include "llvm/Support/SMLoc.h"
28 #include "llvm/Support/TargetParser.h"
29 #include "llvm/Support/VersionTuple.h"
39 class AssemblerConstantPools;
40 class formatted_raw_ostream;
43 struct MCCodePaddingContext;
45 struct MCDwarfFrameInfo;
51 class MCSymbolRefExpr;
52 class MCSubtargetInfo;
56 using MCSectionSubPair = std::pair<MCSection *, const MCExpr *>;
58 /// Target specific streamer interface. This is used so that targets can
59 /// implement support for target specific assembly directives.
61 /// If target foo wants to use this, it should implement 3 classes:
62 /// * FooTargetStreamer : public MCTargetStreamer
63 /// * FooTargetAsmStreamer : public FooTargetStreamer
64 /// * FooTargetELFStreamer : public FooTargetStreamer
66 /// FooTargetStreamer should have a pure virtual method for each directive. For
67 /// example, for a ".bar symbol_name" directive, it should have
68 /// virtual emitBar(const MCSymbol &Symbol) = 0;
70 /// The FooTargetAsmStreamer and FooTargetELFStreamer classes implement the
71 /// method. The assembly streamer just prints ".bar symbol_name". The object
72 /// streamer does whatever is needed to implement .bar in the object file.
74 /// In the assembly printer and parser the target streamer can be used by
75 /// calling getTargetStreamer and casting it to FooTargetStreamer:
77 /// MCTargetStreamer &TS = OutStreamer.getTargetStreamer();
78 /// FooTargetStreamer &ATS = static_cast<FooTargetStreamer &>(TS);
80 /// The base classes FooTargetAsmStreamer and FooTargetELFStreamer should
81 /// *never* be treated differently. Callers should always talk to a
82 /// FooTargetStreamer.
83 class MCTargetStreamer {
88 MCTargetStreamer(MCStreamer &S);
89 virtual ~MCTargetStreamer();
91 MCStreamer &getStreamer() { return Streamer; }
93 // Allow a target to add behavior to the EmitLabel of MCStreamer.
94 virtual void emitLabel(MCSymbol *Symbol);
95 // Allow a target to add behavior to the emitAssignment of MCStreamer.
96 virtual void emitAssignment(MCSymbol *Symbol, const MCExpr *Value);
98 virtual void prettyPrintAsm(MCInstPrinter &InstPrinter, raw_ostream &OS,
99 const MCInst &Inst, const MCSubtargetInfo &STI);
101 virtual void emitDwarfFileDirective(StringRef Directive);
103 /// Update streamer for a new active section.
105 /// This is called by PopSection and SwitchSection, if the current
107 virtual void changeSection(const MCSection *CurSection, MCSection *Section,
108 const MCExpr *SubSection, raw_ostream &OS);
110 virtual void emitValue(const MCExpr *Value);
112 /// Emit the bytes in \p Data into the output.
114 /// This is used to emit bytes in \p Data as sequence of .byte directives.
115 virtual void emitRawBytes(StringRef Data);
117 virtual void finish();
120 // FIXME: declared here because it is used from
121 // lib/CodeGen/AsmPrinter/ARMException.cpp.
122 class ARMTargetStreamer : public MCTargetStreamer {
124 ARMTargetStreamer(MCStreamer &S);
125 ~ARMTargetStreamer() override;
127 virtual void emitFnStart();
128 virtual void emitFnEnd();
129 virtual void emitCantUnwind();
130 virtual void emitPersonality(const MCSymbol *Personality);
131 virtual void emitPersonalityIndex(unsigned Index);
132 virtual void emitHandlerData();
133 virtual void emitSetFP(unsigned FpReg, unsigned SpReg,
135 virtual void emitMovSP(unsigned Reg, int64_t Offset = 0);
136 virtual void emitPad(int64_t Offset);
137 virtual void emitRegSave(const SmallVectorImpl<unsigned> &RegList,
139 virtual void emitUnwindRaw(int64_t StackOffset,
140 const SmallVectorImpl<uint8_t> &Opcodes);
142 virtual void switchVendor(StringRef Vendor);
143 virtual void emitAttribute(unsigned Attribute, unsigned Value);
144 virtual void emitTextAttribute(unsigned Attribute, StringRef String);
145 virtual void emitIntTextAttribute(unsigned Attribute, unsigned IntValue,
146 StringRef StringValue = "");
147 virtual void emitFPU(unsigned FPU);
148 virtual void emitArch(ARM::ArchKind Arch);
149 virtual void emitArchExtension(unsigned ArchExt);
150 virtual void emitObjectArch(ARM::ArchKind Arch);
151 void emitTargetAttributes(const MCSubtargetInfo &STI);
152 virtual void finishAttributeSection();
153 virtual void emitInst(uint32_t Inst, char Suffix = '\0');
155 virtual void AnnotateTLSDescriptorSequence(const MCSymbolRefExpr *SRE);
157 virtual void emitThumbSet(MCSymbol *Symbol, const MCExpr *Value);
159 void finish() override;
161 /// Reset any state between object emissions, i.e. the equivalent of
162 /// MCStreamer's reset method.
163 virtual void reset();
165 /// Callback used to implement the ldr= pseudo.
166 /// Add a new entry to the constant pool for the current section and return an
167 /// MCExpr that can be used to refer to the constant pool location.
168 const MCExpr *addConstantPoolEntry(const MCExpr *, SMLoc Loc);
170 /// Callback used to implemnt the .ltorg directive.
171 /// Emit contents of constant pool for the current section.
172 void emitCurrentConstantPool();
175 std::unique_ptr<AssemblerConstantPools> ConstantPools;
178 /// Streaming machine code generation interface.
180 /// This interface is intended to provide a programatic interface that is very
181 /// similar to the level that an assembler .s file provides. It has callbacks
182 /// to emit bytes, handle directives, etc. The implementation of this interface
183 /// retains state to know what the current section is etc.
185 /// There are multiple implementations of this interface: one for writing out
186 /// a .s file, and implementations that write out .o files of various formats.
190 std::unique_ptr<MCTargetStreamer> TargetStreamer;
192 std::vector<MCDwarfFrameInfo> DwarfFrameInfos;
193 MCDwarfFrameInfo *getCurrentDwarfFrameInfo();
195 /// Similar to DwarfFrameInfos, but for SEH unwind info. Chained frames may
196 /// refer to each other, so use std::unique_ptr to provide pointer stability.
197 std::vector<std::unique_ptr<WinEH::FrameInfo>> WinFrameInfos;
199 WinEH::FrameInfo *CurrentWinFrameInfo;
201 /// Tracks an index to represent the order a symbol was emitted in.
202 /// Zero means we did not emit that symbol.
203 DenseMap<const MCSymbol *, unsigned> SymbolOrdering;
205 /// This is stack of current and previous section values saved by
207 SmallVector<std::pair<MCSectionSubPair, MCSectionSubPair>, 4> SectionStack;
209 /// The next unique ID to use when creating a WinCFI-related section (.pdata
210 /// or .xdata). This ID ensures that we have a one-to-one mapping from
211 /// code section to unwind info section, which MSVC's incremental linker
213 unsigned NextWinCFIID = 0;
215 bool UseAssemblerInfoForParsing;
218 MCStreamer(MCContext &Ctx);
220 virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame);
221 virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &CurFrame);
223 WinEH::FrameInfo *getCurrentWinFrameInfo() {
224 return CurrentWinFrameInfo;
227 virtual void EmitWindowsUnwindTables();
229 virtual void EmitRawTextImpl(StringRef String);
231 /// Returns true if the the .cv_loc directive is in the right section.
232 bool checkCVLocSection(unsigned FuncId, unsigned FileNo, SMLoc Loc);
235 MCStreamer(const MCStreamer &) = delete;
236 MCStreamer &operator=(const MCStreamer &) = delete;
237 virtual ~MCStreamer();
239 void visitUsedExpr(const MCExpr &Expr);
240 virtual void visitUsedSymbol(const MCSymbol &Sym);
242 void setTargetStreamer(MCTargetStreamer *TS) {
243 TargetStreamer.reset(TS);
248 virtual void reset();
250 MCContext &getContext() const { return Context; }
252 virtual MCAssembler *getAssemblerPtr() { return nullptr; }
254 void setUseAssemblerInfoForParsing(bool v) { UseAssemblerInfoForParsing = v; }
255 bool getUseAssemblerInfoForParsing() { return UseAssemblerInfoForParsing; }
257 MCTargetStreamer *getTargetStreamer() {
258 return TargetStreamer.get();
261 /// When emitting an object file, create and emit a real label. When emitting
262 /// textual assembly, this should do nothing to avoid polluting our output.
263 virtual MCSymbol *EmitCFILabel();
265 /// Retreive the current frame info if one is available and it is not yet
266 /// closed. Otherwise, issue an error and return null.
267 WinEH::FrameInfo *EnsureValidWinFrameInfo(SMLoc Loc);
269 unsigned getNumFrameInfos();
270 ArrayRef<MCDwarfFrameInfo> getDwarfFrameInfos() const;
272 bool hasUnfinishedDwarfFrameInfo();
274 unsigned getNumWinFrameInfos() { return WinFrameInfos.size(); }
275 ArrayRef<std::unique_ptr<WinEH::FrameInfo>> getWinFrameInfos() const {
276 return WinFrameInfos;
279 void generateCompactUnwindEncodings(MCAsmBackend *MAB);
281 /// \name Assembly File Formatting.
284 /// Return true if this streamer supports verbose assembly and if it is
286 virtual bool isVerboseAsm() const { return false; }
288 /// Return true if this asm streamer supports emitting unformatted text
289 /// to the .s file with EmitRawText.
290 virtual bool hasRawTextSupport() const { return false; }
292 /// Is the integrated assembler required for this streamer to function
294 virtual bool isIntegratedAssemblerRequired() const { return false; }
296 /// Add a textual comment.
298 /// Typically for comments that can be emitted to the generated .s
299 /// file if applicable as a QoI issue to make the output of the compiler
300 /// more readable. This only affects the MCAsmStreamer, and only when
301 /// verbose assembly output is enabled.
303 /// If the comment includes embedded \n's, they will each get the comment
304 /// prefix as appropriate. The added comment should not end with a \n.
305 /// By default, each comment is terminated with an end of line, i.e. the
306 /// EOL param is set to true by default. If one prefers not to end the
307 /// comment with a new line then the EOL param should be passed
308 /// with a false value.
309 virtual void AddComment(const Twine &T, bool EOL = true) {}
311 /// Return a raw_ostream that comments can be written to. Unlike
312 /// AddComment, you are required to terminate comments with \n if you use this
314 virtual raw_ostream &GetCommentOS();
316 /// Print T and prefix it with the comment string (normally #) and
317 /// optionally a tab. This prints the comment immediately, not at the end of
318 /// the current line. It is basically a safe version of EmitRawText: since it
319 /// only prints comments, the object streamer ignores it instead of asserting.
320 virtual void emitRawComment(const Twine &T, bool TabPrefix = true);
322 /// Add explicit comment T. T is required to be a valid
323 /// comment in the output and does not need to be escaped.
324 virtual void addExplicitComment(const Twine &T);
326 /// Emit added explicit comments.
327 virtual void emitExplicitComments();
329 /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
330 virtual void AddBlankLine() {}
334 /// \name Symbol & Section Management
337 /// Return the current section that the streamer is emitting code to.
338 MCSectionSubPair getCurrentSection() const {
339 if (!SectionStack.empty())
340 return SectionStack.back().first;
341 return MCSectionSubPair();
343 MCSection *getCurrentSectionOnly() const { return getCurrentSection().first; }
345 /// Return the previous section that the streamer is emitting code to.
346 MCSectionSubPair getPreviousSection() const {
347 if (!SectionStack.empty())
348 return SectionStack.back().second;
349 return MCSectionSubPair();
352 /// Returns an index to represent the order a symbol was emitted in.
353 /// (zero if we did not emit that symbol)
354 unsigned GetSymbolOrder(const MCSymbol *Sym) const {
355 return SymbolOrdering.lookup(Sym);
358 /// Update streamer for a new active section.
360 /// This is called by PopSection and SwitchSection, if the current
362 virtual void ChangeSection(MCSection *, const MCExpr *);
364 /// Save the current and previous section on the section stack.
366 SectionStack.push_back(
367 std::make_pair(getCurrentSection(), getPreviousSection()));
370 /// Restore the current and previous section from the section stack.
371 /// Calls ChangeSection as needed.
373 /// Returns false if the stack was empty.
375 if (SectionStack.size() <= 1)
377 auto I = SectionStack.end();
379 MCSectionSubPair OldSection = I->first;
381 MCSectionSubPair NewSection = I->first;
383 if (OldSection != NewSection)
384 ChangeSection(NewSection.first, NewSection.second);
385 SectionStack.pop_back();
389 bool SubSection(const MCExpr *Subsection) {
390 if (SectionStack.empty())
393 SwitchSection(SectionStack.back().first.first, Subsection);
397 /// Set the current section where code is being emitted to \p Section. This
398 /// is required to update CurSection.
400 /// This corresponds to assembler directives like .section, .text, etc.
401 virtual void SwitchSection(MCSection *Section,
402 const MCExpr *Subsection = nullptr);
404 /// Set the current section where code is being emitted to \p Section.
405 /// This is required to update CurSection. This version does not call
407 void SwitchSectionNoChange(MCSection *Section,
408 const MCExpr *Subsection = nullptr) {
409 assert(Section && "Cannot switch to a null section!");
410 MCSectionSubPair curSection = SectionStack.back().first;
411 SectionStack.back().second = curSection;
412 if (MCSectionSubPair(Section, Subsection) != curSection)
413 SectionStack.back().first = MCSectionSubPair(Section, Subsection);
416 /// Create the default sections and set the initial one.
417 virtual void InitSections(bool NoExecStack);
419 MCSymbol *endSection(MCSection *Section);
421 /// Sets the symbol's section.
423 /// Each emitted symbol will be tracked in the ordering table,
424 /// so we can sort on them later.
425 void AssignFragment(MCSymbol *Symbol, MCFragment *Fragment);
427 /// Emit a label for \p Symbol into the current section.
429 /// This corresponds to an assembler statement such as:
432 /// \param Symbol - The symbol to emit. A given symbol should only be
433 /// emitted as a label once, and symbols emitted as a label should never be
434 /// used in an assignment.
435 // FIXME: These emission are non-const because we mutate the symbol to
436 // add the section we're emitting it to later.
437 virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc());
439 virtual void EmitEHSymAttributes(const MCSymbol *Symbol, MCSymbol *EHSymbol);
441 /// Note in the output the specified \p Flag.
442 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
444 /// Emit the given list \p Options of strings as linker
445 /// options into the output.
446 virtual void EmitLinkerOptions(ArrayRef<std::string> Kind) {}
448 /// Note in the output the specified region \p Kind.
449 virtual void EmitDataRegion(MCDataRegionType Kind) {}
451 /// Specify the Mach-O minimum deployment target version.
452 virtual void EmitVersionMin(MCVersionMinType Type, unsigned Major,
453 unsigned Minor, unsigned Update,
454 VersionTuple SDKVersion) {}
456 /// Emit/Specify Mach-O build version command.
457 /// \p Platform should be one of MachO::PlatformType.
458 virtual void EmitBuildVersion(unsigned Platform, unsigned Major,
459 unsigned Minor, unsigned Update,
460 VersionTuple SDKVersion) {}
462 void EmitVersionForTarget(const Triple &Target,
463 const VersionTuple &SDKVersion);
465 /// Note in the output that the specified \p Func is a Thumb mode
466 /// function (ARM target only).
467 virtual void EmitThumbFunc(MCSymbol *Func);
469 /// Emit an assignment of \p Value to \p Symbol.
471 /// This corresponds to an assembler statement such as:
474 /// The assignment generates no code, but has the side effect of binding the
475 /// value in the current context. For the assembly streamer, this prints the
476 /// binding into the .s file.
478 /// \param Symbol - The symbol being assigned to.
479 /// \param Value - The value for the symbol.
480 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
482 /// Emit an weak reference from \p Alias to \p Symbol.
484 /// This corresponds to an assembler statement such as:
485 /// .weakref alias, symbol
487 /// \param Alias - The alias that is being created.
488 /// \param Symbol - The symbol being aliased.
489 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
491 /// Add the given \p Attribute to \p Symbol.
492 virtual bool EmitSymbolAttribute(MCSymbol *Symbol,
493 MCSymbolAttr Attribute) = 0;
495 /// Set the \p DescValue for the \p Symbol.
497 /// \param Symbol - The symbol to have its n_desc field set.
498 /// \param DescValue - The value to set into the n_desc field.
499 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
501 /// Start emitting COFF symbol definition
503 /// \param Symbol - The symbol to have its External & Type fields set.
504 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol);
506 /// Emit the storage class of the symbol.
508 /// \param StorageClass - The storage class the symbol should have.
509 virtual void EmitCOFFSymbolStorageClass(int StorageClass);
511 /// Emit the type of the symbol.
513 /// \param Type - A COFF type identifier (see COFF::SymbolType in X86COFF.h)
514 virtual void EmitCOFFSymbolType(int Type);
516 /// Marks the end of the symbol definition.
517 virtual void EndCOFFSymbolDef();
519 virtual void EmitCOFFSafeSEH(MCSymbol const *Symbol);
521 /// Emits the symbol table index of a Symbol into the current section.
522 virtual void EmitCOFFSymbolIndex(MCSymbol const *Symbol);
524 /// Emits a COFF section index.
526 /// \param Symbol - Symbol the section number relocation should point to.
527 virtual void EmitCOFFSectionIndex(MCSymbol const *Symbol);
529 /// Emits a COFF section relative relocation.
531 /// \param Symbol - Symbol the section relative relocation should point to.
532 virtual void EmitCOFFSecRel32(MCSymbol const *Symbol, uint64_t Offset);
534 /// Emits a COFF image relative relocation.
536 /// \param Symbol - Symbol the image relative relocation should point to.
537 virtual void EmitCOFFImgRel32(MCSymbol const *Symbol, int64_t Offset);
539 /// Emit an ELF .size directive.
541 /// This corresponds to an assembler statement such as:
542 /// .size symbol, expression
543 virtual void emitELFSize(MCSymbol *Symbol, const MCExpr *Value);
545 /// Emit an ELF .symver directive.
547 /// This corresponds to an assembler statement such as:
548 /// .symver _start, foo@@SOME_VERSION
549 /// \param AliasName - The versioned alias (i.e. "foo@@SOME_VERSION")
550 /// \param Aliasee - The aliased symbol (i.e. "_start")
551 virtual void emitELFSymverDirective(StringRef AliasName,
552 const MCSymbol *Aliasee);
554 /// Emit a Linker Optimization Hint (LOH) directive.
555 /// \param Args - Arguments of the LOH.
556 virtual void EmitLOHDirective(MCLOHType Kind, const MCLOHArgs &Args) {}
558 /// Emit a common symbol.
560 /// \param Symbol - The common symbol to emit.
561 /// \param Size - The size of the common symbol.
562 /// \param ByteAlignment - The alignment of the symbol if
563 /// non-zero. This must be a power of 2.
564 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
565 unsigned ByteAlignment) = 0;
567 /// Emit a local common (.lcomm) symbol.
569 /// \param Symbol - The common symbol to emit.
570 /// \param Size - The size of the common symbol.
571 /// \param ByteAlignment - The alignment of the common symbol in bytes.
572 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
573 unsigned ByteAlignment);
575 /// Emit the zerofill section and an optional symbol.
577 /// \param Section - The zerofill section to create and or to put the symbol
578 /// \param Symbol - The zerofill symbol to emit, if non-NULL.
579 /// \param Size - The size of the zerofill symbol.
580 /// \param ByteAlignment - The alignment of the zerofill symbol if
581 /// non-zero. This must be a power of 2 on some targets.
582 virtual void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
583 uint64_t Size = 0, unsigned ByteAlignment = 0,
584 SMLoc Loc = SMLoc()) = 0;
586 /// Emit a thread local bss (.tbss) symbol.
588 /// \param Section - The thread local common section.
589 /// \param Symbol - The thread local common symbol to emit.
590 /// \param Size - The size of the symbol.
591 /// \param ByteAlignment - The alignment of the thread local common symbol
592 /// if non-zero. This must be a power of 2 on some targets.
593 virtual void EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
594 uint64_t Size, unsigned ByteAlignment = 0);
597 /// \name Generating Data
600 /// Emit the bytes in \p Data into the output.
602 /// This is used to implement assembler directives such as .byte, .ascii,
604 virtual void EmitBytes(StringRef Data);
606 /// Functionally identical to EmitBytes. When emitting textual assembly, this
607 /// method uses .byte directives instead of .ascii or .asciz for readability.
608 virtual void EmitBinaryData(StringRef Data);
610 /// Emit the expression \p Value into the output as a native
611 /// integer of the given \p Size bytes.
613 /// This is used to implement assembler directives such as .word, .quad,
616 /// \param Value - The value to emit.
617 /// \param Size - The size of the integer (in bytes) to emit. This must
618 /// match a native machine width.
619 /// \param Loc - The location of the expression for error reporting.
620 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
621 SMLoc Loc = SMLoc());
623 void EmitValue(const MCExpr *Value, unsigned Size, SMLoc Loc = SMLoc());
625 /// Special case of EmitValue that avoids the client having
626 /// to pass in a MCExpr for constant integers.
627 virtual void EmitIntValue(uint64_t Value, unsigned Size);
629 /// Special case of EmitValue that avoids the client having to pass
630 /// in a MCExpr for constant integers & prints in Hex format for certain
632 virtual void EmitIntValueInHex(uint64_t Value, unsigned Size) {
633 EmitIntValue(Value, Size);
636 virtual void EmitULEB128Value(const MCExpr *Value);
638 virtual void EmitSLEB128Value(const MCExpr *Value);
640 /// Special case of EmitULEB128Value that avoids the client having to
641 /// pass in a MCExpr for constant integers.
642 void EmitULEB128IntValue(uint64_t Value, unsigned PadTo = 0);
644 /// Special case of EmitSLEB128Value that avoids the client having to
645 /// pass in a MCExpr for constant integers.
646 void EmitSLEB128IntValue(int64_t Value);
648 /// Special case of EmitValue that avoids the client having to pass in
649 /// a MCExpr for MCSymbols.
650 void EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
651 bool IsSectionRelative = false);
653 /// Emit the expression \p Value into the output as a dtprel
654 /// (64-bit DTP relative) value.
656 /// This is used to implement assembler directives such as .dtpreldword on
657 /// targets that support them.
658 virtual void EmitDTPRel64Value(const MCExpr *Value);
660 /// Emit the expression \p Value into the output as a dtprel
661 /// (32-bit DTP relative) value.
663 /// This is used to implement assembler directives such as .dtprelword on
664 /// targets that support them.
665 virtual void EmitDTPRel32Value(const MCExpr *Value);
667 /// Emit the expression \p Value into the output as a tprel
668 /// (64-bit TP relative) value.
670 /// This is used to implement assembler directives such as .tpreldword on
671 /// targets that support them.
672 virtual void EmitTPRel64Value(const MCExpr *Value);
674 /// Emit the expression \p Value into the output as a tprel
675 /// (32-bit TP relative) value.
677 /// This is used to implement assembler directives such as .tprelword on
678 /// targets that support them.
679 virtual void EmitTPRel32Value(const MCExpr *Value);
681 /// Emit the expression \p Value into the output as a gprel64 (64-bit
682 /// GP relative) value.
684 /// This is used to implement assembler directives such as .gpdword on
685 /// targets that support them.
686 virtual void EmitGPRel64Value(const MCExpr *Value);
688 /// Emit the expression \p Value into the output as a gprel32 (32-bit
689 /// GP relative) value.
691 /// This is used to implement assembler directives such as .gprel32 on
692 /// targets that support them.
693 virtual void EmitGPRel32Value(const MCExpr *Value);
695 /// Emit NumBytes bytes worth of the value specified by FillValue.
696 /// This implements directives such as '.space'.
697 void emitFill(uint64_t NumBytes, uint8_t FillValue);
699 /// Emit \p Size bytes worth of the value specified by \p FillValue.
701 /// This is used to implement assembler directives such as .space or .skip.
703 /// \param NumBytes - The number of bytes to emit.
704 /// \param FillValue - The value to use when filling bytes.
705 /// \param Loc - The location of the expression for error reporting.
706 virtual void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
707 SMLoc Loc = SMLoc());
709 /// Emit \p NumValues copies of \p Size bytes. Each \p Size bytes is
710 /// taken from the lowest order 4 bytes of \p Expr expression.
712 /// This is used to implement assembler directives such as .fill.
714 /// \param NumValues - The number of copies of \p Size bytes to emit.
715 /// \param Size - The size (in bytes) of each repeated value.
716 /// \param Expr - The expression from which \p Size bytes are used.
717 virtual void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
718 SMLoc Loc = SMLoc());
720 /// Emit NumBytes worth of zeros.
721 /// This function properly handles data in virtual sections.
722 void EmitZeros(uint64_t NumBytes);
724 /// Emit some number of copies of \p Value until the byte alignment \p
725 /// ByteAlignment is reached.
727 /// If the number of bytes need to emit for the alignment is not a multiple
728 /// of \p ValueSize, then the contents of the emitted fill bytes is
731 /// This used to implement the .align assembler directive.
733 /// \param ByteAlignment - The alignment to reach. This must be a power of
734 /// two on some targets.
735 /// \param Value - The value to use when filling bytes.
736 /// \param ValueSize - The size of the integer (in bytes) to emit for
737 /// \p Value. This must match a native machine width.
738 /// \param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
739 /// the alignment cannot be reached in this many bytes, no bytes are
741 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
742 unsigned ValueSize = 1,
743 unsigned MaxBytesToEmit = 0);
745 /// Emit nops until the byte alignment \p ByteAlignment is reached.
747 /// This used to align code where the alignment bytes may be executed. This
748 /// can emit different bytes for different sizes to optimize execution.
750 /// \param ByteAlignment - The alignment to reach. This must be a power of
751 /// two on some targets.
752 /// \param MaxBytesToEmit - The maximum numbers of bytes to emit, or 0. If
753 /// the alignment cannot be reached in this many bytes, no bytes are
755 virtual void EmitCodeAlignment(unsigned ByteAlignment,
756 unsigned MaxBytesToEmit = 0);
758 /// Emit some number of copies of \p Value until the byte offset \p
759 /// Offset is reached.
761 /// This is used to implement assembler directives such as .org.
763 /// \param Offset - The offset to reach. This may be an expression, but the
764 /// expression must be associated with the current section.
765 /// \param Value - The value to use when filling bytes.
766 virtual void emitValueToOffset(const MCExpr *Offset, unsigned char Value,
770 EmitCodePaddingBasicBlockStart(const MCCodePaddingContext &Context) {}
773 EmitCodePaddingBasicBlockEnd(const MCCodePaddingContext &Context) {}
777 /// Switch to a new logical file. This is used to implement the '.file
778 /// "foo.c"' assembler directive.
779 virtual void EmitFileDirective(StringRef Filename);
781 /// Emit the "identifiers" directive. This implements the
782 /// '.ident "version foo"' assembler directive.
783 virtual void EmitIdent(StringRef IdentString) {}
785 /// Associate a filename with a specified logical file number. This
786 /// implements the DWARF2 '.file 4 "foo.c"' assembler directive.
787 unsigned EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
789 Optional<MD5::MD5Result> Checksum = None,
790 Optional<StringRef> Source = None,
793 tryEmitDwarfFileDirective(FileNo, Directory, Filename, Checksum,
797 /// Associate a filename with a specified logical file number.
798 /// Also associate a directory, optional checksum, and optional source
799 /// text with the logical file. This implements the DWARF2
800 /// '.file 4 "dir/foo.c"' assembler directive, and the DWARF5
801 /// '.file 4 "dir/foo.c" md5 "..." source "..."' assembler directive.
802 virtual Expected<unsigned> tryEmitDwarfFileDirective(
803 unsigned FileNo, StringRef Directory, StringRef Filename,
804 Optional<MD5::MD5Result> Checksum = None, Optional<StringRef> Source = None,
807 /// Specify the "root" file of the compilation, using the ".file 0" extension.
808 virtual void emitDwarfFile0Directive(StringRef Directory, StringRef Filename,
809 Optional<MD5::MD5Result> Checksum,
810 Optional<StringRef> Source,
813 virtual void EmitCFIBKeyFrame();
815 /// This implements the DWARF2 '.loc fileno lineno ...' assembler
817 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
818 unsigned Column, unsigned Flags,
819 unsigned Isa, unsigned Discriminator,
822 /// Associate a filename with a specified logical file number, and also
823 /// specify that file's checksum information. This implements the '.cv_file 4
824 /// "foo.c"' assembler directive. Returns true on success.
825 virtual bool EmitCVFileDirective(unsigned FileNo, StringRef Filename,
826 ArrayRef<uint8_t> Checksum,
827 unsigned ChecksumKind);
829 /// Introduces a function id for use with .cv_loc.
830 virtual bool EmitCVFuncIdDirective(unsigned FunctionId);
832 /// Introduces an inline call site id for use with .cv_loc. Includes
833 /// extra information for inline line table generation.
834 virtual bool EmitCVInlineSiteIdDirective(unsigned FunctionId, unsigned IAFunc,
835 unsigned IAFile, unsigned IALine,
836 unsigned IACol, SMLoc Loc);
838 /// This implements the CodeView '.cv_loc' assembler directive.
839 virtual void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo,
840 unsigned Line, unsigned Column,
841 bool PrologueEnd, bool IsStmt,
842 StringRef FileName, SMLoc Loc);
844 /// This implements the CodeView '.cv_linetable' assembler directive.
845 virtual void EmitCVLinetableDirective(unsigned FunctionId,
846 const MCSymbol *FnStart,
847 const MCSymbol *FnEnd);
849 /// This implements the CodeView '.cv_inline_linetable' assembler
851 virtual void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
852 unsigned SourceFileId,
853 unsigned SourceLineNum,
854 const MCSymbol *FnStartSym,
855 const MCSymbol *FnEndSym);
857 /// This implements the CodeView '.cv_def_range' assembler
859 virtual void EmitCVDefRangeDirective(
860 ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
861 StringRef FixedSizePortion);
863 /// This implements the CodeView '.cv_stringtable' assembler directive.
864 virtual void EmitCVStringTableDirective() {}
866 /// This implements the CodeView '.cv_filechecksums' assembler directive.
867 virtual void EmitCVFileChecksumsDirective() {}
869 /// This implements the CodeView '.cv_filechecksumoffset' assembler
871 virtual void EmitCVFileChecksumOffsetDirective(unsigned FileNo) {}
873 /// This implements the CodeView '.cv_fpo_data' assembler directive.
874 virtual void EmitCVFPOData(const MCSymbol *ProcSym, SMLoc Loc = {}) {}
876 /// Emit the absolute difference between two symbols.
878 /// \pre Offset of \c Hi is greater than the offset \c Lo.
879 virtual void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
882 /// Emit the absolute difference between two symbols encoded with ULEB128.
883 virtual void emitAbsoluteSymbolDiffAsULEB128(const MCSymbol *Hi,
886 virtual MCSymbol *getDwarfLineTableSymbol(unsigned CUID);
887 virtual void EmitCFISections(bool EH, bool Debug);
888 void EmitCFIStartProc(bool IsSimple, SMLoc Loc = SMLoc());
889 void EmitCFIEndProc();
890 virtual void EmitCFIDefCfa(int64_t Register, int64_t Offset);
891 virtual void EmitCFIDefCfaOffset(int64_t Offset);
892 virtual void EmitCFIDefCfaRegister(int64_t Register);
893 virtual void EmitCFIOffset(int64_t Register, int64_t Offset);
894 virtual void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding);
895 virtual void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding);
896 virtual void EmitCFIRememberState();
897 virtual void EmitCFIRestoreState();
898 virtual void EmitCFISameValue(int64_t Register);
899 virtual void EmitCFIRestore(int64_t Register);
900 virtual void EmitCFIRelOffset(int64_t Register, int64_t Offset);
901 virtual void EmitCFIAdjustCfaOffset(int64_t Adjustment);
902 virtual void EmitCFIEscape(StringRef Values);
903 virtual void EmitCFIReturnColumn(int64_t Register);
904 virtual void EmitCFIGnuArgsSize(int64_t Size);
905 virtual void EmitCFISignalFrame();
906 virtual void EmitCFIUndefined(int64_t Register);
907 virtual void EmitCFIRegister(int64_t Register1, int64_t Register2);
908 virtual void EmitCFIWindowSave();
909 virtual void EmitCFINegateRAState();
911 virtual void EmitWinCFIStartProc(const MCSymbol *Symbol, SMLoc Loc = SMLoc());
912 virtual void EmitWinCFIEndProc(SMLoc Loc = SMLoc());
913 /// This is used on platforms, such as Windows on ARM64, that require function
914 /// or funclet sizes to be emitted in .xdata before the End marker is emitted
915 /// for the frame. We cannot use the End marker, as it is not set at the
916 /// point of emitting .xdata, in order to indicate that the frame is active.
917 virtual void EmitWinCFIFuncletOrFuncEnd(SMLoc Loc = SMLoc());
918 virtual void EmitWinCFIStartChained(SMLoc Loc = SMLoc());
919 virtual void EmitWinCFIEndChained(SMLoc Loc = SMLoc());
920 virtual void EmitWinCFIPushReg(unsigned Register, SMLoc Loc = SMLoc());
921 virtual void EmitWinCFISetFrame(unsigned Register, unsigned Offset,
922 SMLoc Loc = SMLoc());
923 virtual void EmitWinCFIAllocStack(unsigned Size, SMLoc Loc = SMLoc());
924 virtual void EmitWinCFISaveReg(unsigned Register, unsigned Offset,
925 SMLoc Loc = SMLoc());
926 virtual void EmitWinCFISaveXMM(unsigned Register, unsigned Offset,
927 SMLoc Loc = SMLoc());
928 virtual void EmitWinCFIPushFrame(bool Code, SMLoc Loc = SMLoc());
929 virtual void EmitWinCFIEndProlog(SMLoc Loc = SMLoc());
930 virtual void EmitWinEHHandler(const MCSymbol *Sym, bool Unwind, bool Except,
931 SMLoc Loc = SMLoc());
932 virtual void EmitWinEHHandlerData(SMLoc Loc = SMLoc());
934 virtual void emitCGProfileEntry(const MCSymbolRefExpr *From,
935 const MCSymbolRefExpr *To, uint64_t Count);
937 /// Get the .pdata section used for the given section. Typically the given
938 /// section is either the main .text section or some other COMDAT .text
939 /// section, but it may be any section containing code.
940 MCSection *getAssociatedPDataSection(const MCSection *TextSec);
942 /// Get the .xdata section used for the given section.
943 MCSection *getAssociatedXDataSection(const MCSection *TextSec);
945 virtual void EmitSyntaxDirective();
947 /// Emit a .reloc directive.
948 /// Returns true if the relocation could not be emitted because Name is not
950 virtual bool EmitRelocDirective(const MCExpr &Offset, StringRef Name,
951 const MCExpr *Expr, SMLoc Loc,
952 const MCSubtargetInfo &STI) {
956 virtual void EmitAddrsig() {}
957 virtual void EmitAddrsigSym(const MCSymbol *Sym) {}
959 /// Emit the given \p Instruction into the current section.
960 virtual void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI);
962 /// Set the bundle alignment mode from now on in the section.
963 /// The argument is the power of 2 to which the alignment is set. The
964 /// value 0 means turn the bundle alignment off.
965 virtual void EmitBundleAlignMode(unsigned AlignPow2);
967 /// The following instructions are a bundle-locked group.
969 /// \param AlignToEnd - If true, the bundle-locked group will be aligned to
970 /// the end of a bundle.
971 virtual void EmitBundleLock(bool AlignToEnd);
973 /// Ends a bundle-locked group.
974 virtual void EmitBundleUnlock();
976 /// If this file is backed by a assembly streamer, this dumps the
977 /// specified string in the output .s file. This capability is indicated by
978 /// the hasRawTextSupport() predicate. By default this aborts.
979 void EmitRawText(const Twine &String);
981 /// Streamer specific finalization.
982 virtual void FinishImpl();
983 /// Finish emission of machine code.
986 virtual bool mayHaveInstructions(MCSection &Sec) const { return true; }
989 /// Create a dummy machine code streamer, which does nothing. This is useful for
990 /// timing the assembler front end.
991 MCStreamer *createNullStreamer(MCContext &Ctx);
993 /// Create a machine code streamer which will print out assembly for the native
994 /// target, suitable for compiling with a native assembler.
996 /// \param InstPrint - If given, the instruction printer to use. If not given
997 /// the MCInst representation will be printed. This method takes ownership of
1000 /// \param CE - If given, a code emitter to use to show the instruction
1001 /// encoding inline with the assembly. This method takes ownership of \p CE.
1003 /// \param TAB - If given, a target asm backend to use to show the fixup
1004 /// information in conjunction with encoding information. This method takes
1005 /// ownership of \p TAB.
1007 /// \param ShowInst - Whether to show the MCInst representation inline with
1009 MCStreamer *createAsmStreamer(MCContext &Ctx,
1010 std::unique_ptr<formatted_raw_ostream> OS,
1011 bool isVerboseAsm, bool useDwarfDirectory,
1012 MCInstPrinter *InstPrint, MCCodeEmitter *CE,
1013 MCAsmBackend *TAB, bool ShowInst);
1015 } // end namespace llvm
1017 #endif // LLVM_MC_MCSTREAMER_H