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/Twine.h"
19 #include "llvm/MC/MCDwarf.h"
20 #include "llvm/MC/SectionKind.h"
21 #include "llvm/Support/Allocator.h"
22 #include "llvm/Support/Compiler.h"
23 #include "llvm/Support/raw_ostream.h"
26 #include <vector> // FIXME: Shouldn't be needed.
37 class MCObjectFileInfo;
45 /// Context object for machine code objects. This class owns all of the
46 /// sections that it creates.
49 MCContext(const MCContext &) = delete;
50 MCContext &operator=(const MCContext &) = delete;
53 typedef StringMap<MCSymbol *, BumpPtrAllocator &> SymbolTable;
56 /// The SourceMgr for this object, if any.
57 const SourceMgr *SrcMgr;
59 /// The MCAsmInfo for this target.
62 /// The MCRegisterInfo for this target.
63 const MCRegisterInfo *MRI;
65 /// The MCObjectFileInfo for this target.
66 const MCObjectFileInfo *MOFI;
68 /// Allocator object used for creating machine code objects.
70 /// We use a bump pointer allocator to avoid the need to track all allocated
72 BumpPtrAllocator Allocator;
74 /// Bindings of names to symbols.
77 /// ELF sections can have a corresponding symbol. This maps one to the
79 DenseMap<const MCSectionELF *, MCSymbolELF *> SectionSymbols;
81 /// A mapping from a local label number and an instance count to a symbol.
82 /// For example, in the assembly
86 /// We have three labels represented by the pairs (1, 0), (2, 0) and (1, 1)
87 DenseMap<std::pair<unsigned, unsigned>, MCSymbol *> LocalSymbols;
89 /// Keeps tracks of names that were used both for used declared and
90 /// artificial symbols.
91 StringMap<bool, BumpPtrAllocator &> UsedNames;
93 /// The next ID to dole out to an unnamed assembler temporary symbol with
95 StringMap<unsigned> NextID;
97 /// Instances of directional local labels.
98 DenseMap<unsigned, MCLabel *> Instances;
99 /// NextInstance() creates the next instance of the directional local label
100 /// for the LocalLabelVal and adds it to the map if needed.
101 unsigned NextInstance(unsigned LocalLabelVal);
102 /// GetInstance() gets the current instance of the directional local label
103 /// for the LocalLabelVal and adds it to the map if needed.
104 unsigned GetInstance(unsigned LocalLabelVal);
106 /// The file name of the log file from the environment variable
107 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique
108 /// directive is used or it is an error.
110 /// The stream that gets written to for the .secure_log_unique directive.
111 raw_ostream *SecureLog;
112 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to
113 /// catch errors if .secure_log_unique appears twice without
114 /// .secure_log_reset appearing between them.
117 /// The compilation directory to use for DW_AT_comp_dir.
118 SmallString<128> CompilationDir;
120 /// The main file name if passed in explicitly.
121 std::string MainFileName;
123 /// The dwarf file and directory tables from the dwarf .file directive.
124 /// We now emit a line table for each compile unit. To reduce the prologue
125 /// size of each line table, the files and directories used by each compile
126 /// unit are separated.
127 std::map<unsigned, MCDwarfLineTable> MCDwarfLineTablesCUMap;
129 /// The current dwarf line information from the last dwarf .loc directive.
130 MCDwarfLoc CurrentDwarfLoc;
133 /// Generate dwarf debugging info for assembly source files.
134 bool GenDwarfForAssembly;
136 /// The current dwarf file number when generate dwarf debugging info for
137 /// assembly source files.
138 unsigned GenDwarfFileNumber;
140 /// Sections for generating the .debug_ranges and .debug_aranges sections.
141 SetVector<MCSection *> SectionsForRanges;
143 /// The information gathered from labels that will have dwarf label
144 /// entries when generating dwarf assembly source files.
145 std::vector<MCGenDwarfLabelEntry> MCGenDwarfLabelEntries;
147 /// The string to embed in the debug information for the compile unit, if
149 StringRef DwarfDebugFlags;
151 /// The string to embed in as the dwarf AT_producer for the compile unit, if
153 StringRef DwarfDebugProducer;
155 /// The maximum version of dwarf that we should emit.
156 uint16_t DwarfVersion;
158 /// Honor temporary labels, this is useful for debugging semantic
159 /// differences between temporary and non-temporary labels (primarily on
161 bool AllowTemporaryLabels;
162 bool UseNamesOnTempLabels = true;
164 /// The Compile Unit ID that we are currently processing.
165 unsigned DwarfCompileUnitID;
167 struct ELFSectionKey {
168 std::string SectionName;
171 ELFSectionKey(StringRef SectionName, StringRef GroupName,
173 : SectionName(SectionName), GroupName(GroupName), UniqueID(UniqueID) {
175 bool operator<(const ELFSectionKey &Other) const {
176 if (SectionName != Other.SectionName)
177 return SectionName < Other.SectionName;
178 if (GroupName != Other.GroupName)
179 return GroupName < Other.GroupName;
180 return UniqueID < Other.UniqueID;
184 struct COFFSectionKey {
185 std::string SectionName;
188 COFFSectionKey(StringRef SectionName, StringRef GroupName,
190 : SectionName(SectionName), GroupName(GroupName),
191 SelectionKey(SelectionKey) {}
192 bool operator<(const COFFSectionKey &Other) const {
193 if (SectionName != Other.SectionName)
194 return SectionName < Other.SectionName;
195 if (GroupName != Other.GroupName)
196 return GroupName < Other.GroupName;
197 return SelectionKey < Other.SelectionKey;
201 StringMap<MCSectionMachO *> MachOUniquingMap;
202 std::map<ELFSectionKey, MCSectionELF *> ELFUniquingMap;
203 std::map<COFFSectionKey, MCSectionCOFF *> COFFUniquingMap;
204 StringMap<bool> ELFRelSecNames;
206 /// Do automatic reset in destructor
209 MCSymbol *createSymbolImpl(const StringMapEntry<bool> *Name,
211 MCSymbol *createSymbol(StringRef Name, bool AlwaysAddSuffix,
214 MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
218 explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI,
219 const MCObjectFileInfo *MOFI,
220 const SourceMgr *Mgr = nullptr, bool DoAutoReset = true);
223 const SourceMgr *getSourceManager() const { return SrcMgr; }
225 const MCAsmInfo *getAsmInfo() const { return MAI; }
227 const MCRegisterInfo *getRegisterInfo() const { return MRI; }
229 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; }
231 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; }
232 void setUseNamesOnTempLabels(bool Value) { UseNamesOnTempLabels = Value; }
234 /// \name Module Lifetime Management
237 /// reset - return object to right after construction state to prepare
238 /// to process a new module
243 /// \name Symbol Management
246 /// Create and return a new linker temporary symbol with a unique but
247 /// unspecified name.
248 MCSymbol *createLinkerPrivateTempSymbol();
250 /// Create and return a new assembler temporary symbol with a unique but
251 /// unspecified name.
252 MCSymbol *createTempSymbol(bool CanBeUnnamed = true);
254 MCSymbol *createTempSymbol(const Twine &Name, bool AlwaysAddSuffix,
255 bool CanBeUnnamed = true);
257 /// Create the definition of a directional local symbol for numbered label
258 /// (used for "1:" definitions).
259 MCSymbol *createDirectionalLocalSymbol(unsigned LocalLabelVal);
261 /// Create and return a directional local symbol for numbered label (used
262 /// for "1b" or 1f" references).
263 MCSymbol *getDirectionalLocalSymbol(unsigned LocalLabelVal, bool Before);
265 /// Lookup the symbol inside with the specified \p Name. If it exists,
266 /// return it. If not, create a forward reference and return it.
268 /// \param Name - The symbol name, which must be unique across all symbols.
269 MCSymbol *getOrCreateSymbol(const Twine &Name);
271 MCSymbolELF *getOrCreateSectionSymbol(const MCSectionELF &Section);
273 /// Gets a symbol that will be defined to the final stack offset of a local
274 /// variable after codegen.
276 /// \param Idx - The index of a local variable passed to @llvm.frameescape.
277 MCSymbol *getOrCreateFrameAllocSymbol(StringRef FuncName, unsigned Idx);
279 MCSymbol *getOrCreateParentFrameOffsetSymbol(StringRef FuncName);
281 MCSymbol *getOrCreateLSDASymbol(StringRef FuncName);
283 /// Get the symbol for \p Name, or null.
284 MCSymbol *lookupSymbol(const Twine &Name) const;
286 /// getSymbols - Get a reference for the symbol table for clients that
287 /// want to, for example, iterate over all symbols. 'const' because we
288 /// still want any modifications to the table itself to use the MCContext
290 const SymbolTable &getSymbols() const { return Symbols; }
294 /// \name Section Management
297 /// Return the MCSection for the specified mach-o section. This requires
298 /// the operands to be valid.
299 MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
300 unsigned TypeAndAttributes,
301 unsigned Reserved2, SectionKind K,
302 const char *BeginSymName = nullptr);
304 MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
305 unsigned TypeAndAttributes, SectionKind K,
306 const char *BeginSymName = nullptr) {
307 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K,
311 MCSectionELF *getELFSection(StringRef Section, unsigned Type,
313 return getELFSection(Section, Type, Flags, nullptr);
316 MCSectionELF *getELFSection(StringRef Section, unsigned Type,
317 unsigned Flags, const char *BeginSymName) {
318 return getELFSection(Section, Type, Flags, 0, "", BeginSymName);
321 MCSectionELF *getELFSection(StringRef Section, unsigned Type,
322 unsigned Flags, unsigned EntrySize,
324 return getELFSection(Section, Type, Flags, EntrySize, Group, nullptr);
327 MCSectionELF *getELFSection(StringRef Section, unsigned Type,
328 unsigned Flags, unsigned EntrySize,
329 StringRef Group, const char *BeginSymName) {
330 return getELFSection(Section, Type, Flags, EntrySize, Group, ~0,
334 MCSectionELF *getELFSection(StringRef Section, unsigned Type,
335 unsigned Flags, unsigned EntrySize,
336 StringRef Group, unsigned UniqueID) {
337 return getELFSection(Section, Type, Flags, EntrySize, Group, UniqueID,
341 MCSectionELF *getELFSection(StringRef Section, unsigned Type,
342 unsigned Flags, unsigned EntrySize,
343 StringRef Group, unsigned UniqueID,
344 const char *BeginSymName);
346 MCSectionELF *getELFSection(StringRef Section, unsigned Type,
347 unsigned Flags, unsigned EntrySize,
348 const MCSymbolELF *Group, unsigned UniqueID,
349 const char *BeginSymName,
350 const MCSectionELF *Associated);
352 MCSectionELF *createELFRelSection(StringRef Name, unsigned Type,
353 unsigned Flags, unsigned EntrySize,
354 const MCSymbolELF *Group,
355 const MCSectionELF *Associated);
357 void renameELFSection(MCSectionELF *Section, StringRef Name);
359 MCSectionELF *createELFGroupSection(const MCSymbolELF *Group);
361 MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
362 SectionKind Kind, StringRef COMDATSymName,
364 const char *BeginSymName = nullptr);
366 MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
368 const char *BeginSymName = nullptr);
370 MCSectionCOFF *getCOFFSection(StringRef Section);
372 /// Gets or creates a section equivalent to Sec that is associated with the
373 /// section containing KeySym. For example, to create a debug info section
374 /// associated with an inline function, pass the normal debug info section
375 /// as Sec and the function symbol as KeySym.
376 MCSectionCOFF *getAssociativeCOFFSection(MCSectionCOFF *Sec,
377 const MCSymbol *KeySym);
381 /// \name Dwarf Management
384 /// \brief Get the compilation directory for DW_AT_comp_dir
385 /// This can be overridden by clients which want to control the reported
386 /// compilation directory and have it be something other than the current
387 /// working directory.
388 /// Returns an empty string if the current directory cannot be determined.
389 StringRef getCompilationDir() const { return CompilationDir; }
391 /// \brief Set the compilation directory for DW_AT_comp_dir
392 /// Override the default (CWD) compilation directory.
393 void setCompilationDir(StringRef S) { CompilationDir = S.str(); }
395 /// \brief Get the main file name for use in error messages and debug
396 /// info. This can be set to ensure we've got the correct file name
397 /// after preprocessing or for -save-temps.
398 const std::string &getMainFileName() const { return MainFileName; }
400 /// \brief Set the main file name and override the default.
401 void setMainFileName(StringRef S) { MainFileName = S; }
403 /// Creates an entry in the dwarf file and directory tables.
404 unsigned getDwarfFile(StringRef Directory, StringRef FileName,
405 unsigned FileNumber, unsigned CUID);
407 bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0);
409 const std::map<unsigned, MCDwarfLineTable> &getMCDwarfLineTables() const {
410 return MCDwarfLineTablesCUMap;
413 MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) {
414 return MCDwarfLineTablesCUMap[CUID];
417 const MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) const {
418 auto I = MCDwarfLineTablesCUMap.find(CUID);
419 assert(I != MCDwarfLineTablesCUMap.end());
423 const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles(unsigned CUID = 0) {
424 return getMCDwarfLineTable(CUID).getMCDwarfFiles();
426 const SmallVectorImpl<std::string> &getMCDwarfDirs(unsigned CUID = 0) {
427 return getMCDwarfLineTable(CUID).getMCDwarfDirs();
430 bool hasMCLineSections() const {
431 for (const auto &Table : MCDwarfLineTablesCUMap)
432 if (!Table.second.getMCDwarfFiles().empty() || Table.second.getLabel())
436 unsigned getDwarfCompileUnitID() { return DwarfCompileUnitID; }
437 void setDwarfCompileUnitID(unsigned CUIndex) {
438 DwarfCompileUnitID = CUIndex;
440 void setMCLineTableCompilationDir(unsigned CUID, StringRef CompilationDir) {
441 getMCDwarfLineTable(CUID).setCompilationDir(CompilationDir);
444 /// Saves the information from the currently parsed dwarf .loc directive
445 /// and sets DwarfLocSeen. When the next instruction is assembled an entry
446 /// in the line number table with this information and the address of the
447 /// instruction will be created.
448 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column,
449 unsigned Flags, unsigned Isa,
450 unsigned Discriminator) {
451 CurrentDwarfLoc.setFileNum(FileNum);
452 CurrentDwarfLoc.setLine(Line);
453 CurrentDwarfLoc.setColumn(Column);
454 CurrentDwarfLoc.setFlags(Flags);
455 CurrentDwarfLoc.setIsa(Isa);
456 CurrentDwarfLoc.setDiscriminator(Discriminator);
459 void clearDwarfLocSeen() { DwarfLocSeen = false; }
461 bool getDwarfLocSeen() { return DwarfLocSeen; }
462 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; }
464 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; }
465 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; }
466 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; }
467 void setGenDwarfFileNumber(unsigned FileNumber) {
468 GenDwarfFileNumber = FileNumber;
470 const SetVector<MCSection *> &getGenDwarfSectionSyms() {
471 return SectionsForRanges;
473 bool addGenDwarfSection(MCSection *Sec) {
474 return SectionsForRanges.insert(Sec);
477 void finalizeDwarfSections(MCStreamer &MCOS);
478 const std::vector<MCGenDwarfLabelEntry> &getMCGenDwarfLabelEntries() const {
479 return MCGenDwarfLabelEntries;
481 void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E) {
482 MCGenDwarfLabelEntries.push_back(E);
485 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; }
486 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; }
488 void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; }
489 StringRef getDwarfDebugProducer() { return DwarfDebugProducer; }
491 void setDwarfVersion(uint16_t v) { DwarfVersion = v; }
492 uint16_t getDwarfVersion() const { return DwarfVersion; }
496 char *getSecureLogFile() { return SecureLogFile; }
497 raw_ostream *getSecureLog() { return SecureLog; }
498 bool getSecureLogUsed() { return SecureLogUsed; }
499 void setSecureLog(raw_ostream *Value) { SecureLog = Value; }
500 void setSecureLogUsed(bool Value) { SecureLogUsed = Value; }
502 void *allocate(unsigned Size, unsigned Align = 8) {
503 return Allocator.Allocate(Size, Align);
505 void deallocate(void *Ptr) {}
507 // Unrecoverable error has occurred. Display the best diagnostic we can
508 // and bail via exit(1). For now, most MC backend errors are unrecoverable.
509 // FIXME: We should really do something about that.
510 LLVM_ATTRIBUTE_NORETURN void reportFatalError(SMLoc L,
511 const Twine &Msg) const;
514 } // end namespace llvm
516 // operator new and delete aren't allowed inside namespaces.
517 // The throw specifications are mandated by the standard.
518 /// \brief Placement new for using the MCContext's allocator.
520 /// This placement form of operator new uses the MCContext's allocator for
521 /// obtaining memory. It is a non-throwing new, which means that it returns
522 /// null on error. (If that is what the allocator does. The current does, so if
523 /// this ever changes, this operator will have to be changed, too.)
524 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
526 /// // Default alignment (8)
527 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
528 /// // Specific alignment
529 /// IntegerLiteral *Ex2 = new (Context, 4) IntegerLiteral(arguments);
531 /// Please note that you cannot use delete on the pointer; it must be
532 /// deallocated using an explicit destructor call followed by
533 /// \c Context.Deallocate(Ptr).
535 /// \param Bytes The number of bytes to allocate. Calculated by the compiler.
536 /// \param C The MCContext that provides the allocator.
537 /// \param Alignment The alignment of the allocated memory (if the underlying
538 /// allocator supports it).
539 /// \return The allocated memory. Could be NULL.
540 inline void *operator new(size_t Bytes, llvm::MCContext &C,
541 size_t Alignment = 8) throw() {
542 return C.allocate(Bytes, Alignment);
544 /// \brief Placement delete companion to the new above.
546 /// This operator is just a companion to the new above. There is no way of
547 /// invoking it directly; see the new operator for more details. This operator
548 /// is called implicitly by the compiler if a placement new expression using
549 /// the MCContext throws in the object constructor.
550 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t)
555 /// This placement form of operator new[] uses the MCContext's allocator for
556 /// obtaining memory. It is a non-throwing new[], which means that it returns
558 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
560 /// // Default alignment (8)
561 /// char *data = new (Context) char[10];
562 /// // Specific alignment
563 /// char *data = new (Context, 4) char[10];
565 /// Please note that you cannot use delete on the pointer; it must be
566 /// deallocated using an explicit destructor call followed by
567 /// \c Context.Deallocate(Ptr).
569 /// \param Bytes The number of bytes to allocate. Calculated by the compiler.
570 /// \param C The MCContext that provides the allocator.
571 /// \param Alignment The alignment of the allocated memory (if the underlying
572 /// allocator supports it).
573 /// \return The allocated memory. Could be NULL.
574 inline void *operator new[](size_t Bytes, llvm::MCContext& C,
575 size_t Alignment = 8) throw() {
576 return C.allocate(Bytes, Alignment);
579 /// \brief Placement delete[] companion to the new[] above.
581 /// This operator is just a companion to the new[] above. There is no way of
582 /// invoking it directly; see the new[] operator for more details. This operator
583 /// is called implicitly by the compiler if a placement new[] expression using
584 /// the MCContext throws in the object constructor.
585 inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () {