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/MC/MCDwarf.h"
19 #include "llvm/MC/MCStreamer.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.
36 class MCObjectFileInfo;
46 /// MCContext - Context object for machine code objects. This class owns all
47 /// of the sections that it creates.
50 MCContext(const MCContext&) = delete;
51 MCContext &operator=(const MCContext&) = delete;
53 typedef StringMap<MCSymbol*, BumpPtrAllocator&> SymbolTable;
55 /// The SourceMgr for this object, if any.
56 const SourceMgr *SrcMgr;
58 /// The MCAsmInfo for this target.
61 /// The MCRegisterInfo for this target.
62 const MCRegisterInfo *MRI;
64 /// The MCObjectFileInfo for this target.
65 const MCObjectFileInfo *MOFI;
67 /// Allocator - Allocator object used for creating machine code objects.
69 /// We use a bump pointer allocator to avoid the need to track all allocated
71 BumpPtrAllocator Allocator;
73 /// Symbols - Bindings of names to symbols.
76 /// ELF sections can have a corresponding symbol. This maps one to the
78 DenseMap<const MCSectionELF*, MCSymbol*> SectionSymbols;
80 /// A maping from a local label number and an instance count to a symbol.
81 /// For example, in the assembly
85 /// We have three labels represented by the pairs (1, 0), (2, 0) and (1, 1)
86 DenseMap<std::pair<unsigned, unsigned>, MCSymbol*> LocalSymbols;
88 /// UsedNames - Keeps tracks of names that were used both for used declared
89 /// and artificial symbols.
90 StringMap<bool, BumpPtrAllocator&> UsedNames;
92 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary
94 unsigned NextUniqueID;
96 /// Instances of directional local labels.
97 DenseMap<unsigned, MCLabel *> Instances;
98 /// NextInstance() creates the next instance of the directional local label
99 /// for the LocalLabelVal and adds it to the map if needed.
100 unsigned NextInstance(unsigned LocalLabelVal);
101 /// GetInstance() gets the current instance of the directional local label
102 /// for the LocalLabelVal and adds it to the map if needed.
103 unsigned GetInstance(unsigned LocalLabelVal);
105 /// The file name of the log file from the environment variable
106 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique
107 /// directive is used or it is an error.
109 /// The stream that gets written to for the .secure_log_unique directive.
110 raw_ostream *SecureLog;
111 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to
112 /// catch errors if .secure_log_unique appears twice without
113 /// .secure_log_reset appearing between them.
116 /// The compilation directory to use for DW_AT_comp_dir.
117 SmallString<128> CompilationDir;
119 /// The main file name if passed in explicitly.
120 std::string MainFileName;
122 /// The dwarf file and directory tables from the dwarf .file directive.
123 /// We now emit a line table for each compile unit. To reduce the prologue
124 /// size of each line table, the files and directories used by each compile
125 /// unit are separated.
126 std::map<unsigned, MCDwarfLineTable> MCDwarfLineTablesCUMap;
128 /// The current dwarf line information from the last dwarf .loc directive.
129 MCDwarfLoc CurrentDwarfLoc;
132 /// Generate dwarf debugging info for assembly source files.
133 bool GenDwarfForAssembly;
135 /// The current dwarf file number when generate dwarf debugging info for
136 /// assembly source files.
137 unsigned GenDwarfFileNumber;
139 /// Symbols created for the start and end of each section, used for
140 /// generating the .debug_ranges and .debug_aranges sections.
141 MapVector<const MCSection *, std::pair<MCSymbol *, MCSymbol *> >
144 /// The information gathered from labels that will have dwarf label
145 /// entries when generating dwarf assembly source files.
146 std::vector<MCGenDwarfLabelEntry> MCGenDwarfLabelEntries;
148 /// The string to embed in the debug information for the compile unit, if
150 StringRef DwarfDebugFlags;
152 /// The string to embed in as the dwarf AT_producer for the compile unit, if
154 StringRef DwarfDebugProducer;
156 /// The maximum version of dwarf that we should emit.
157 uint16_t DwarfVersion;
159 /// Honor temporary labels, this is useful for debugging semantic
160 /// differences between temporary and non-temporary labels (primarily on
162 bool AllowTemporaryLabels;
164 /// The Compile Unit ID that we are currently processing.
165 unsigned DwarfCompileUnitID;
167 typedef std::pair<std::string, std::string> SectionGroupPair;
168 typedef std::tuple<std::string, std::string, int> SectionGroupTriple;
170 StringMap<const MCSectionMachO*> MachOUniquingMap;
171 std::map<SectionGroupPair, const MCSectionELF *> ELFUniquingMap;
172 std::map<SectionGroupTriple, const MCSectionCOFF *> COFFUniquingMap;
174 /// Do automatic reset in destructor
177 MCSymbol *CreateSymbol(StringRef Name);
179 MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
183 explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI,
184 const MCObjectFileInfo *MOFI,
185 const SourceMgr *Mgr = nullptr, bool DoAutoReset = true);
188 const SourceMgr *getSourceManager() const { return SrcMgr; }
190 const MCAsmInfo *getAsmInfo() const { return MAI; }
192 const MCRegisterInfo *getRegisterInfo() const { return MRI; }
194 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; }
196 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; }
198 /// @name Module Lifetime Management
201 /// reset - return object to right after construction state to prepare
202 /// to process a new module
207 /// @name Symbol Management
210 /// CreateLinkerPrivateTempSymbol - Create and return a new linker temporary
211 /// symbol with a unique but unspecified name.
212 MCSymbol *CreateLinkerPrivateTempSymbol();
214 /// CreateTempSymbol - Create and return a new assembler temporary symbol
215 /// with a unique but unspecified name.
216 MCSymbol *CreateTempSymbol();
218 /// getUniqueSymbolID() - Return a unique identifier for use in constructing
220 unsigned getUniqueSymbolID() { return NextUniqueID++; }
222 /// Create the definition of a directional local symbol for numbered label
223 /// (used for "1:" definitions).
224 MCSymbol *CreateDirectionalLocalSymbol(unsigned LocalLabelVal);
226 /// Create and return a directional local symbol for numbered label (used
227 /// for "1b" or 1f" references).
228 MCSymbol *GetDirectionalLocalSymbol(unsigned LocalLabelVal, bool Before);
230 /// GetOrCreateSymbol - Lookup the symbol inside with the specified
231 /// @p Name. If it exists, return it. If not, create a forward
232 /// reference and return it.
234 /// @param Name - The symbol name, which must be unique across all symbols.
235 MCSymbol *GetOrCreateSymbol(StringRef Name);
236 MCSymbol *GetOrCreateSymbol(const Twine &Name);
238 MCSymbol *getOrCreateSectionSymbol(const MCSectionELF &Section);
240 MCSymbol *getOrCreateFrameAllocSymbol(StringRef FuncName);
242 /// LookupSymbol - Get the symbol for \p Name, or null.
243 MCSymbol *LookupSymbol(StringRef Name) const;
244 MCSymbol *LookupSymbol(const Twine &Name) const;
246 /// getSymbols - Get a reference for the symbol table for clients that
247 /// want to, for example, iterate over all symbols. 'const' because we
248 /// still want any modifications to the table itself to use the MCContext
250 const SymbolTable &getSymbols() const {
256 /// @name Section Management
259 /// getMachOSection - Return the MCSection for the specified mach-o section.
260 /// This requires the operands to be valid.
261 const MCSectionMachO *getMachOSection(StringRef Segment,
263 unsigned TypeAndAttributes,
266 const MCSectionMachO *getMachOSection(StringRef Segment,
268 unsigned TypeAndAttributes,
270 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
273 const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
276 const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
277 unsigned Flags, unsigned EntrySize,
280 const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
281 unsigned Flags, unsigned EntrySize,
282 StringRef Group, bool Unique);
284 void renameELFSection(const MCSectionELF *Section, StringRef Name);
286 const MCSectionELF *CreateELFGroupSection();
288 const MCSectionCOFF *getCOFFSection(StringRef Section,
289 unsigned Characteristics,
291 StringRef COMDATSymName, int Selection);
293 const MCSectionCOFF *getCOFFSection(StringRef Section,
294 unsigned Characteristics,
297 const MCSectionCOFF *getCOFFSection(StringRef Section);
299 /// Gets or creates a section equivalent to Sec that is associated with the
300 /// section containing KeySym. For example, to create a debug info section
301 /// associated with an inline function, pass the normal debug info section
302 /// as Sec and the function symbol as KeySym.
303 const MCSectionCOFF *getAssociativeCOFFSection(const MCSectionCOFF *Sec,
304 const MCSymbol *KeySym);
308 /// @name Dwarf Management
311 /// \brief Get the compilation directory for DW_AT_comp_dir
312 /// This can be overridden by clients which want to control the reported
313 /// compilation directory and have it be something other than the current
314 /// working directory.
315 /// Returns an empty string if the current directory cannot be determined.
316 StringRef getCompilationDir() const { return CompilationDir; }
318 /// \brief Set the compilation directory for DW_AT_comp_dir
319 /// Override the default (CWD) compilation directory.
320 void setCompilationDir(StringRef S) { CompilationDir = S.str(); }
322 /// \brief Get the main file name for use in error messages and debug
323 /// info. This can be set to ensure we've got the correct file name
324 /// after preprocessing or for -save-temps.
325 const std::string &getMainFileName() const { return MainFileName; }
327 /// \brief Set the main file name and override the default.
328 void setMainFileName(StringRef S) { MainFileName = S; }
330 /// GetDwarfFile - creates an entry in the dwarf file and directory tables.
331 unsigned GetDwarfFile(StringRef Directory, StringRef FileName,
332 unsigned FileNumber, unsigned CUID);
334 bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0);
336 const std::map<unsigned, MCDwarfLineTable> &getMCDwarfLineTables() const {
337 return MCDwarfLineTablesCUMap;
340 MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) {
341 return MCDwarfLineTablesCUMap[CUID];
344 const MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) const {
345 auto I = MCDwarfLineTablesCUMap.find(CUID);
346 assert(I != MCDwarfLineTablesCUMap.end());
350 const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles(unsigned CUID = 0) {
351 return getMCDwarfLineTable(CUID).getMCDwarfFiles();
353 const SmallVectorImpl<std::string> &getMCDwarfDirs(unsigned CUID = 0) {
354 return getMCDwarfLineTable(CUID).getMCDwarfDirs();
357 bool hasMCLineSections() const {
358 for (const auto &Table : MCDwarfLineTablesCUMap)
359 if (!Table.second.getMCDwarfFiles().empty() || Table.second.getLabel())
363 unsigned getDwarfCompileUnitID() {
364 return DwarfCompileUnitID;
366 void setDwarfCompileUnitID(unsigned CUIndex) {
367 DwarfCompileUnitID = CUIndex;
369 void setMCLineTableCompilationDir(unsigned CUID, StringRef CompilationDir) {
370 getMCDwarfLineTable(CUID).setCompilationDir(CompilationDir);
373 /// setCurrentDwarfLoc - saves the information from the currently parsed
374 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction
375 /// is assembled an entry in the line number table with this information and
376 /// the address of the instruction will be created.
377 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column,
378 unsigned Flags, unsigned Isa,
379 unsigned Discriminator) {
380 CurrentDwarfLoc.setFileNum(FileNum);
381 CurrentDwarfLoc.setLine(Line);
382 CurrentDwarfLoc.setColumn(Column);
383 CurrentDwarfLoc.setFlags(Flags);
384 CurrentDwarfLoc.setIsa(Isa);
385 CurrentDwarfLoc.setDiscriminator(Discriminator);
388 void ClearDwarfLocSeen() { DwarfLocSeen = false; }
390 bool getDwarfLocSeen() { return DwarfLocSeen; }
391 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; }
393 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; }
394 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; }
395 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; }
396 void setGenDwarfFileNumber(unsigned FileNumber) {
397 GenDwarfFileNumber = FileNumber;
399 MapVector<const MCSection *, std::pair<MCSymbol *, MCSymbol *> > &
400 getGenDwarfSectionSyms() {
401 return SectionStartEndSyms;
403 std::pair<MapVector<const MCSection *,
404 std::pair<MCSymbol *, MCSymbol *> >::iterator,
406 addGenDwarfSection(const MCSection *Sec) {
407 return SectionStartEndSyms.insert(
408 std::make_pair(Sec, std::make_pair(nullptr, nullptr)));
410 void finalizeDwarfSections(MCStreamer &MCOS);
411 const std::vector<MCGenDwarfLabelEntry> &getMCGenDwarfLabelEntries() const {
412 return MCGenDwarfLabelEntries;
414 void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E) {
415 MCGenDwarfLabelEntries.push_back(E);
418 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; }
419 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; }
421 void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; }
422 StringRef getDwarfDebugProducer() { return DwarfDebugProducer; }
424 void setDwarfVersion(uint16_t v) { DwarfVersion = v; }
425 uint16_t getDwarfVersion() const { return DwarfVersion; }
429 char *getSecureLogFile() { return SecureLogFile; }
430 raw_ostream *getSecureLog() { return SecureLog; }
431 bool getSecureLogUsed() { return SecureLogUsed; }
432 void setSecureLog(raw_ostream *Value) {
435 void setSecureLogUsed(bool Value) {
436 SecureLogUsed = Value;
439 void *Allocate(unsigned Size, unsigned Align = 8) {
440 return Allocator.Allocate(Size, Align);
442 void Deallocate(void *Ptr) {
445 // Unrecoverable error has occurred. Display the best diagnostic we can
446 // and bail via exit(1). For now, most MC backend errors are unrecoverable.
447 // FIXME: We should really do something about that.
448 LLVM_ATTRIBUTE_NORETURN void FatalError(SMLoc L, const Twine &Msg) const;
451 } // end namespace llvm
453 // operator new and delete aren't allowed inside namespaces.
454 // The throw specifications are mandated by the standard.
455 /// @brief Placement new for using the MCContext's allocator.
457 /// This placement form of operator new uses the MCContext's allocator for
458 /// obtaining memory. It is a non-throwing new, which means that it returns
459 /// null on error. (If that is what the allocator does. The current does, so if
460 /// this ever changes, this operator will have to be changed, too.)
461 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
463 /// // Default alignment (16)
464 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
465 /// // Specific alignment
466 /// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments);
468 /// Please note that you cannot use delete on the pointer; it must be
469 /// deallocated using an explicit destructor call followed by
470 /// @c Context.Deallocate(Ptr).
472 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
473 /// @param C The MCContext that provides the allocator.
474 /// @param Alignment The alignment of the allocated memory (if the underlying
475 /// allocator supports it).
476 /// @return The allocated memory. Could be NULL.
477 inline void *operator new(size_t Bytes, llvm::MCContext &C,
478 size_t Alignment = 16) throw () {
479 return C.Allocate(Bytes, Alignment);
481 /// @brief Placement delete companion to the new above.
483 /// This operator is just a companion to the new above. There is no way of
484 /// invoking it directly; see the new operator for more details. This operator
485 /// is called implicitly by the compiler if a placement new expression using
486 /// the MCContext throws in the object constructor.
487 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t)
492 /// This placement form of operator new[] uses the MCContext's allocator for
493 /// obtaining memory. It is a non-throwing new[], which means that it returns
495 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
497 /// // Default alignment (16)
498 /// char *data = new (Context) char[10];
499 /// // Specific alignment
500 /// char *data = new (Context, 8) char[10];
502 /// Please note that you cannot use delete on the pointer; it must be
503 /// deallocated using an explicit destructor call followed by
504 /// @c Context.Deallocate(Ptr).
506 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
507 /// @param C The MCContext that provides the allocator.
508 /// @param Alignment The alignment of the allocated memory (if the underlying
509 /// allocator supports it).
510 /// @return The allocated memory. Could be NULL.
511 inline void *operator new[](size_t Bytes, llvm::MCContext& C,
512 size_t Alignment = 16) throw () {
513 return C.Allocate(Bytes, Alignment);
516 /// @brief Placement delete[] companion to the new[] above.
518 /// This operator is just a companion to the new[] above. There is no way of
519 /// invoking it directly; see the new[] operator for more details. This operator
520 /// is called implicitly by the compiler if a placement new[] expression using
521 /// the MCContext throws in the object constructor.
522 inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () {