1 //===- MCContext.h - Machine Code Context -----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCCONTEXT_H
11 #define LLVM_MC_MCCONTEXT_H
13 #include "llvm/ADT/DenseMap.h"
14 #include "llvm/ADT/SetVector.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/ADT/StringMap.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/BinaryFormat/Dwarf.h"
21 #include "llvm/MC/MCDwarf.h"
22 #include "llvm/MC/MCSubtargetInfo.h"
23 #include "llvm/MC/SectionKind.h"
24 #include "llvm/Support/Allocator.h"
25 #include "llvm/Support/Compiler.h"
26 #include "llvm/Support/raw_ostream.h"
39 class CodeViewContext;
42 class MCObjectFileInfo;
56 /// Context object for machine code objects. This class owns all of the
57 /// sections that it creates.
61 using SymbolTable = StringMap<MCSymbol *, BumpPtrAllocator &>;
64 /// The SourceMgr for this object, if any.
65 const SourceMgr *SrcMgr;
67 /// The SourceMgr for inline assembly, if any.
68 SourceMgr *InlineSrcMgr;
70 /// The MCAsmInfo for this target.
73 /// The MCRegisterInfo for this target.
74 const MCRegisterInfo *MRI;
76 /// The MCObjectFileInfo for this target.
77 const MCObjectFileInfo *MOFI;
79 std::unique_ptr<CodeViewContext> CVContext;
81 /// Allocator object used for creating machine code objects.
83 /// We use a bump pointer allocator to avoid the need to track all allocated
85 BumpPtrAllocator Allocator;
87 SpecificBumpPtrAllocator<MCSectionCOFF> COFFAllocator;
88 SpecificBumpPtrAllocator<MCSectionELF> ELFAllocator;
89 SpecificBumpPtrAllocator<MCSectionMachO> MachOAllocator;
90 SpecificBumpPtrAllocator<MCSectionWasm> WasmAllocator;
92 /// Bindings of names to symbols.
95 /// A mapping from a local label number and an instance count to a symbol.
96 /// For example, in the assembly
100 /// We have three labels represented by the pairs (1, 0), (2, 0) and (1, 1)
101 DenseMap<std::pair<unsigned, unsigned>, MCSymbol *> LocalSymbols;
103 /// Keeps tracks of names that were used both for used declared and
104 /// artificial symbols. The value is "true" if the name has been used for a
105 /// non-section symbol (there can be at most one of those, plus an unlimited
106 /// number of section symbols with the same name).
107 StringMap<bool, BumpPtrAllocator &> UsedNames;
109 /// The next ID to dole out to an unnamed assembler temporary symbol with
111 StringMap<unsigned> NextID;
113 /// Instances of directional local labels.
114 DenseMap<unsigned, MCLabel *> Instances;
115 /// NextInstance() creates the next instance of the directional local label
116 /// for the LocalLabelVal and adds it to the map if needed.
117 unsigned NextInstance(unsigned LocalLabelVal);
118 /// GetInstance() gets the current instance of the directional local label
119 /// for the LocalLabelVal and adds it to the map if needed.
120 unsigned GetInstance(unsigned LocalLabelVal);
122 /// The file name of the log file from the environment variable
123 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique
124 /// directive is used or it is an error.
126 /// The stream that gets written to for the .secure_log_unique directive.
127 std::unique_ptr<raw_fd_ostream> SecureLog;
128 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to
129 /// catch errors if .secure_log_unique appears twice without
130 /// .secure_log_reset appearing between them.
131 bool SecureLogUsed = false;
133 /// The compilation directory to use for DW_AT_comp_dir.
134 SmallString<128> CompilationDir;
136 /// The main file name if passed in explicitly.
137 std::string MainFileName;
139 /// The dwarf file and directory tables from the dwarf .file directive.
140 /// We now emit a line table for each compile unit. To reduce the prologue
141 /// size of each line table, the files and directories used by each compile
142 /// unit are separated.
143 std::map<unsigned, MCDwarfLineTable> MCDwarfLineTablesCUMap;
145 /// The current dwarf line information from the last dwarf .loc directive.
146 MCDwarfLoc CurrentDwarfLoc;
147 bool DwarfLocSeen = false;
149 /// Generate dwarf debugging info for assembly source files.
150 bool GenDwarfForAssembly = false;
152 /// The current dwarf file number when generate dwarf debugging info for
153 /// assembly source files.
154 unsigned GenDwarfFileNumber = 0;
156 /// Sections for generating the .debug_ranges and .debug_aranges sections.
157 SetVector<MCSection *> SectionsForRanges;
159 /// The information gathered from labels that will have dwarf label
160 /// entries when generating dwarf assembly source files.
161 std::vector<MCGenDwarfLabelEntry> MCGenDwarfLabelEntries;
163 /// The string to embed in the debug information for the compile unit, if
165 StringRef DwarfDebugFlags;
167 /// The string to embed in as the dwarf AT_producer for the compile unit, if
169 StringRef DwarfDebugProducer;
171 /// The maximum version of dwarf that we should emit.
172 uint16_t DwarfVersion = 4;
174 /// Honor temporary labels, this is useful for debugging semantic
175 /// differences between temporary and non-temporary labels (primarily on
177 bool AllowTemporaryLabels = true;
178 bool UseNamesOnTempLabels = true;
180 /// The Compile Unit ID that we are currently processing.
181 unsigned DwarfCompileUnitID = 0;
183 struct ELFSectionKey {
184 std::string SectionName;
188 ELFSectionKey(StringRef SectionName, StringRef GroupName,
190 : SectionName(SectionName), GroupName(GroupName), UniqueID(UniqueID) {
193 bool operator<(const ELFSectionKey &Other) const {
194 if (SectionName != Other.SectionName)
195 return SectionName < Other.SectionName;
196 if (GroupName != Other.GroupName)
197 return GroupName < Other.GroupName;
198 return UniqueID < Other.UniqueID;
202 struct COFFSectionKey {
203 std::string SectionName;
208 COFFSectionKey(StringRef SectionName, StringRef GroupName,
209 int SelectionKey, unsigned UniqueID)
210 : SectionName(SectionName), GroupName(GroupName),
211 SelectionKey(SelectionKey), UniqueID(UniqueID) {}
213 bool operator<(const COFFSectionKey &Other) const {
214 if (SectionName != Other.SectionName)
215 return SectionName < Other.SectionName;
216 if (GroupName != Other.GroupName)
217 return GroupName < Other.GroupName;
218 if (SelectionKey != Other.SelectionKey)
219 return SelectionKey < Other.SelectionKey;
220 return UniqueID < Other.UniqueID;
224 struct WasmSectionKey {
225 std::string SectionName;
229 WasmSectionKey(StringRef SectionName, StringRef GroupName,
231 : SectionName(SectionName), GroupName(GroupName), UniqueID(UniqueID) {
234 bool operator<(const WasmSectionKey &Other) const {
235 if (SectionName != Other.SectionName)
236 return SectionName < Other.SectionName;
237 if (GroupName != Other.GroupName)
238 return GroupName < Other.GroupName;
239 return UniqueID < Other.UniqueID;
243 StringMap<MCSectionMachO *> MachOUniquingMap;
244 std::map<ELFSectionKey, MCSectionELF *> ELFUniquingMap;
245 std::map<COFFSectionKey, MCSectionCOFF *> COFFUniquingMap;
246 std::map<WasmSectionKey, MCSectionWasm *> WasmUniquingMap;
247 StringMap<bool> RelSecNames;
249 SpecificBumpPtrAllocator<MCSubtargetInfo> MCSubtargetAllocator;
251 /// Do automatic reset in destructor
254 bool HadError = false;
256 MCSymbol *createSymbolImpl(const StringMapEntry<bool> *Name,
258 MCSymbol *createSymbol(StringRef Name, bool AlwaysAddSuffix,
261 MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
264 MCSectionELF *createELFSectionImpl(StringRef Section, unsigned Type,
265 unsigned Flags, SectionKind K,
267 const MCSymbolELF *Group,
269 const MCSymbolELF *Associated);
272 explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI,
273 const MCObjectFileInfo *MOFI,
274 const SourceMgr *Mgr = nullptr, bool DoAutoReset = true);
275 MCContext(const MCContext &) = delete;
276 MCContext &operator=(const MCContext &) = delete;
279 const SourceMgr *getSourceManager() const { return SrcMgr; }
281 void setInlineSourceManager(SourceMgr *SM) { InlineSrcMgr = SM; }
283 const MCAsmInfo *getAsmInfo() const { return MAI; }
285 const MCRegisterInfo *getRegisterInfo() const { return MRI; }
287 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; }
289 CodeViewContext &getCVContext();
291 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; }
292 void setUseNamesOnTempLabels(bool Value) { UseNamesOnTempLabels = Value; }
294 /// \name Module Lifetime Management
297 /// reset - return object to right after construction state to prepare
298 /// to process a new module
303 /// \name Symbol Management
306 /// Create and return a new linker temporary symbol with a unique but
307 /// unspecified name.
308 MCSymbol *createLinkerPrivateTempSymbol();
310 /// Create and return a new assembler temporary symbol with a unique but
311 /// unspecified name.
312 MCSymbol *createTempSymbol(bool CanBeUnnamed = true);
314 MCSymbol *createTempSymbol(const Twine &Name, bool AlwaysAddSuffix,
315 bool CanBeUnnamed = true);
317 /// Create the definition of a directional local symbol for numbered label
318 /// (used for "1:" definitions).
319 MCSymbol *createDirectionalLocalSymbol(unsigned LocalLabelVal);
321 /// Create and return a directional local symbol for numbered label (used
322 /// for "1b" or 1f" references).
323 MCSymbol *getDirectionalLocalSymbol(unsigned LocalLabelVal, bool Before);
325 /// Lookup the symbol inside with the specified \p Name. If it exists,
326 /// return it. If not, create a forward reference and return it.
328 /// \param Name - The symbol name, which must be unique across all symbols.
329 MCSymbol *getOrCreateSymbol(const Twine &Name);
331 /// Gets a symbol that will be defined to the final stack offset of a local
332 /// variable after codegen.
334 /// \param Idx - The index of a local variable passed to @llvm.localescape.
335 MCSymbol *getOrCreateFrameAllocSymbol(StringRef FuncName, unsigned Idx);
337 MCSymbol *getOrCreateParentFrameOffsetSymbol(StringRef FuncName);
339 MCSymbol *getOrCreateLSDASymbol(StringRef FuncName);
341 /// Get the symbol for \p Name, or null.
342 MCSymbol *lookupSymbol(const Twine &Name) const;
344 /// Set value for a symbol.
345 void setSymbolValue(MCStreamer &Streamer, StringRef Sym, uint64_t Val);
347 /// getSymbols - Get a reference for the symbol table for clients that
348 /// want to, for example, iterate over all symbols. 'const' because we
349 /// still want any modifications to the table itself to use the MCContext
351 const SymbolTable &getSymbols() const { return Symbols; }
355 /// \name Section Management
359 /// Pass this value as the UniqueID during section creation to get the
360 /// generic section with the given name and characteristics. The usual
361 /// sections such as .text use this ID.
362 GenericSectionID = ~0U
365 /// Return the MCSection for the specified mach-o section. This requires
366 /// the operands to be valid.
367 MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
368 unsigned TypeAndAttributes,
369 unsigned Reserved2, SectionKind K,
370 const char *BeginSymName = nullptr);
372 MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
373 unsigned TypeAndAttributes, SectionKind K,
374 const char *BeginSymName = nullptr) {
375 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K,
379 MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
381 return getELFSection(Section, Type, Flags, 0, "");
384 MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
385 unsigned Flags, unsigned EntrySize,
386 const Twine &Group) {
387 return getELFSection(Section, Type, Flags, EntrySize, Group, ~0);
390 MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
391 unsigned Flags, unsigned EntrySize,
392 const Twine &Group, unsigned UniqueID) {
393 return getELFSection(Section, Type, Flags, EntrySize, Group, UniqueID,
397 MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
398 unsigned Flags, unsigned EntrySize,
399 const Twine &Group, unsigned UniqueID,
400 const MCSymbolELF *Associated);
402 MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
403 unsigned Flags, unsigned EntrySize,
404 const MCSymbolELF *Group, unsigned UniqueID,
405 const MCSymbolELF *Associated);
407 /// Get a section with the provided group identifier. This section is
408 /// named by concatenating \p Prefix with '.' then \p Suffix. The \p Type
409 /// describes the type of the section and \p Flags are used to further
410 /// configure this named section.
411 MCSectionELF *getELFNamedSection(const Twine &Prefix, const Twine &Suffix,
412 unsigned Type, unsigned Flags,
413 unsigned EntrySize = 0);
415 MCSectionELF *createELFRelSection(const Twine &Name, unsigned Type,
416 unsigned Flags, unsigned EntrySize,
417 const MCSymbolELF *Group,
418 const MCSectionELF *RelInfoSection);
420 void renameELFSection(MCSectionELF *Section, StringRef Name);
422 MCSectionELF *createELFGroupSection(const MCSymbolELF *Group);
424 MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
425 SectionKind Kind, StringRef COMDATSymName,
427 unsigned UniqueID = GenericSectionID,
428 const char *BeginSymName = nullptr);
430 MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
432 const char *BeginSymName = nullptr);
434 MCSectionCOFF *getCOFFSection(StringRef Section);
436 /// Gets or creates a section equivalent to Sec that is associated with the
437 /// section containing KeySym. For example, to create a debug info section
438 /// associated with an inline function, pass the normal debug info section
439 /// as Sec and the function symbol as KeySym.
441 getAssociativeCOFFSection(MCSectionCOFF *Sec, const MCSymbol *KeySym,
442 unsigned UniqueID = GenericSectionID);
444 MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
446 return getWasmSection(Section, Type, Flags, nullptr);
449 MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
450 unsigned Flags, const char *BeginSymName) {
451 return getWasmSection(Section, Type, Flags, "", BeginSymName);
454 MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
455 unsigned Flags, const Twine &Group) {
456 return getWasmSection(Section, Type, Flags, Group, nullptr);
459 MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
460 unsigned Flags, const Twine &Group,
461 const char *BeginSymName) {
462 return getWasmSection(Section, Type, Flags, Group, ~0, BeginSymName);
465 MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
466 unsigned Flags, const Twine &Group,
468 return getWasmSection(Section, Type, Flags, Group, UniqueID, nullptr);
471 MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
472 unsigned Flags, const Twine &Group,
473 unsigned UniqueID, const char *BeginSymName);
475 MCSectionWasm *getWasmSection(const Twine &Section, unsigned Type,
476 unsigned Flags, const MCSymbolWasm *Group,
477 unsigned UniqueID, const char *BeginSymName);
479 /// Get a section with the provided group identifier. This section is
480 /// named by concatenating \p Prefix with '.' then \p Suffix. The \p Type
481 /// describes the type of the section and \p Flags are used to further
482 /// configure this named section.
483 MCSectionWasm *getWasmNamedSection(const Twine &Prefix, const Twine &Suffix,
484 unsigned Type, unsigned Flags);
486 MCSectionWasm *createWasmRelSection(const Twine &Name, unsigned Type,
488 const MCSymbolWasm *Group);
490 void renameWasmSection(MCSectionWasm *Section, StringRef Name);
492 // Create and save a copy of STI and return a reference to the copy.
493 MCSubtargetInfo &getSubtargetCopy(const MCSubtargetInfo &STI);
497 /// \name Dwarf Management
500 /// \brief Get the compilation directory for DW_AT_comp_dir
501 /// The compilation directory should be set with \c setCompilationDir before
502 /// calling this function. If it is unset, an empty string will be returned.
503 StringRef getCompilationDir() const { return CompilationDir; }
505 /// \brief Set the compilation directory for DW_AT_comp_dir
506 void setCompilationDir(StringRef S) { CompilationDir = S.str(); }
508 /// \brief Get the main file name for use in error messages and debug
509 /// info. This can be set to ensure we've got the correct file name
510 /// after preprocessing or for -save-temps.
511 const std::string &getMainFileName() const { return MainFileName; }
513 /// \brief Set the main file name and override the default.
514 void setMainFileName(StringRef S) { MainFileName = S; }
516 /// Creates an entry in the dwarf file and directory tables.
517 unsigned getDwarfFile(StringRef Directory, StringRef FileName,
518 unsigned FileNumber, unsigned CUID);
520 bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0);
522 const std::map<unsigned, MCDwarfLineTable> &getMCDwarfLineTables() const {
523 return MCDwarfLineTablesCUMap;
526 MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) {
527 return MCDwarfLineTablesCUMap[CUID];
530 const MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) const {
531 auto I = MCDwarfLineTablesCUMap.find(CUID);
532 assert(I != MCDwarfLineTablesCUMap.end());
536 const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles(unsigned CUID = 0) {
537 return getMCDwarfLineTable(CUID).getMCDwarfFiles();
540 const SmallVectorImpl<std::string> &getMCDwarfDirs(unsigned CUID = 0) {
541 return getMCDwarfLineTable(CUID).getMCDwarfDirs();
544 bool hasMCLineSections() const {
545 for (const auto &Table : MCDwarfLineTablesCUMap)
546 if (!Table.second.getMCDwarfFiles().empty() || Table.second.getLabel())
551 unsigned getDwarfCompileUnitID() { return DwarfCompileUnitID; }
553 void setDwarfCompileUnitID(unsigned CUIndex) {
554 DwarfCompileUnitID = CUIndex;
557 void setMCLineTableCompilationDir(unsigned CUID, StringRef CompilationDir) {
558 getMCDwarfLineTable(CUID).setCompilationDir(CompilationDir);
561 /// Saves the information from the currently parsed dwarf .loc directive
562 /// and sets DwarfLocSeen. When the next instruction is assembled an entry
563 /// in the line number table with this information and the address of the
564 /// instruction will be created.
565 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column,
566 unsigned Flags, unsigned Isa,
567 unsigned Discriminator) {
568 CurrentDwarfLoc.setFileNum(FileNum);
569 CurrentDwarfLoc.setLine(Line);
570 CurrentDwarfLoc.setColumn(Column);
571 CurrentDwarfLoc.setFlags(Flags);
572 CurrentDwarfLoc.setIsa(Isa);
573 CurrentDwarfLoc.setDiscriminator(Discriminator);
577 void clearDwarfLocSeen() { DwarfLocSeen = false; }
579 bool getDwarfLocSeen() { return DwarfLocSeen; }
580 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; }
582 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; }
583 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; }
584 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; }
586 void setGenDwarfFileNumber(unsigned FileNumber) {
587 GenDwarfFileNumber = FileNumber;
590 const SetVector<MCSection *> &getGenDwarfSectionSyms() {
591 return SectionsForRanges;
594 bool addGenDwarfSection(MCSection *Sec) {
595 return SectionsForRanges.insert(Sec);
598 void finalizeDwarfSections(MCStreamer &MCOS);
600 const std::vector<MCGenDwarfLabelEntry> &getMCGenDwarfLabelEntries() const {
601 return MCGenDwarfLabelEntries;
604 void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E) {
605 MCGenDwarfLabelEntries.push_back(E);
608 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; }
609 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; }
611 void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; }
612 StringRef getDwarfDebugProducer() { return DwarfDebugProducer; }
614 dwarf::DwarfFormat getDwarfFormat() const {
615 // TODO: Support DWARF64
616 return dwarf::DWARF32;
619 void setDwarfVersion(uint16_t v) { DwarfVersion = v; }
620 uint16_t getDwarfVersion() const { return DwarfVersion; }
624 char *getSecureLogFile() { return SecureLogFile; }
625 raw_fd_ostream *getSecureLog() { return SecureLog.get(); }
627 void setSecureLog(std::unique_ptr<raw_fd_ostream> Value) {
628 SecureLog = std::move(Value);
631 bool getSecureLogUsed() { return SecureLogUsed; }
632 void setSecureLogUsed(bool Value) { SecureLogUsed = Value; }
634 void *allocate(unsigned Size, unsigned Align = 8) {
635 return Allocator.Allocate(Size, Align);
638 void deallocate(void *Ptr) {}
640 bool hadError() { return HadError; }
641 void reportError(SMLoc L, const Twine &Msg);
642 // Unrecoverable error has occurred. Display the best diagnostic we can
643 // and bail via exit(1). For now, most MC backend errors are unrecoverable.
644 // FIXME: We should really do something about that.
645 LLVM_ATTRIBUTE_NORETURN void reportFatalError(SMLoc L,
649 } // end namespace llvm
651 // operator new and delete aren't allowed inside namespaces.
652 // The throw specifications are mandated by the standard.
653 /// \brief Placement new for using the MCContext's allocator.
655 /// This placement form of operator new uses the MCContext's allocator for
656 /// obtaining memory. It is a non-throwing new, which means that it returns
657 /// null on error. (If that is what the allocator does. The current does, so if
658 /// this ever changes, this operator will have to be changed, too.)
659 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
661 /// // Default alignment (8)
662 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
663 /// // Specific alignment
664 /// IntegerLiteral *Ex2 = new (Context, 4) IntegerLiteral(arguments);
666 /// Please note that you cannot use delete on the pointer; it must be
667 /// deallocated using an explicit destructor call followed by
668 /// \c Context.Deallocate(Ptr).
670 /// \param Bytes The number of bytes to allocate. Calculated by the compiler.
671 /// \param C The MCContext that provides the allocator.
672 /// \param Alignment The alignment of the allocated memory (if the underlying
673 /// allocator supports it).
674 /// \return The allocated memory. Could be NULL.
675 inline void *operator new(size_t Bytes, llvm::MCContext &C,
676 size_t Alignment = 8) noexcept {
677 return C.allocate(Bytes, Alignment);
679 /// \brief Placement delete companion to the new above.
681 /// This operator is just a companion to the new above. There is no way of
682 /// invoking it directly; see the new operator for more details. This operator
683 /// is called implicitly by the compiler if a placement new expression using
684 /// the MCContext throws in the object constructor.
685 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) noexcept {
689 /// This placement form of operator new[] uses the MCContext's allocator for
690 /// obtaining memory. It is a non-throwing new[], which means that it returns
692 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
694 /// // Default alignment (8)
695 /// char *data = new (Context) char[10];
696 /// // Specific alignment
697 /// char *data = new (Context, 4) char[10];
699 /// Please note that you cannot use delete on the pointer; it must be
700 /// deallocated using an explicit destructor call followed by
701 /// \c Context.Deallocate(Ptr).
703 /// \param Bytes The number of bytes to allocate. Calculated by the compiler.
704 /// \param C The MCContext that provides the allocator.
705 /// \param Alignment The alignment of the allocated memory (if the underlying
706 /// allocator supports it).
707 /// \return The allocated memory. Could be NULL.
708 inline void *operator new[](size_t Bytes, llvm::MCContext &C,
709 size_t Alignment = 8) noexcept {
710 return C.allocate(Bytes, Alignment);
713 /// \brief Placement delete[] companion to the new[] above.
715 /// This operator is just a companion to the new[] above. There is no way of
716 /// invoking it directly; see the new[] operator for more details. This operator
717 /// is called implicitly by the compiler if a placement new[] expression using
718 /// the MCContext throws in the object constructor.
719 inline void operator delete[](void *Ptr, llvm::MCContext &C) noexcept {
723 #endif // LLVM_MC_MCCONTEXT_H