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/SmallString.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/ADT/StringMap.h"
17 #include "llvm/MC/MCDwarf.h"
18 #include "llvm/MC/SectionKind.h"
19 #include "llvm/Support/Allocator.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/raw_ostream.h"
23 #include <vector> // FIXME: Shouldn't be needed.
33 class MCObjectFileInfo;
43 /// MCContext - Context object for machine code objects. This class owns all
44 /// of the sections that it creates.
47 MCContext(const MCContext&) LLVM_DELETED_FUNCTION;
48 MCContext &operator=(const MCContext&) LLVM_DELETED_FUNCTION;
50 typedef StringMap<MCSymbol*, BumpPtrAllocator&> SymbolTable;
52 /// The SourceMgr for this object, if any.
53 const SourceMgr *SrcMgr;
55 /// The MCAsmInfo for this target.
58 /// The MCRegisterInfo for this target.
59 const MCRegisterInfo *MRI;
61 /// The MCObjectFileInfo for this target.
62 const MCObjectFileInfo *MOFI;
64 /// Allocator - Allocator object used for creating machine code objects.
66 /// We use a bump pointer allocator to avoid the need to track all allocated
68 BumpPtrAllocator Allocator;
70 /// Symbols - Bindings of names to symbols.
73 /// A maping from a local label number and an instance count to a symbol.
74 /// For example, in the assembly
78 /// We have three labels represented by the pairs (1, 0), (2, 0) and (1, 1)
79 DenseMap<std::pair<unsigned, unsigned>, MCSymbol*> LocalSymbols;
81 /// UsedNames - Keeps tracks of names that were used both for used declared
82 /// and artificial symbols.
83 StringMap<bool, BumpPtrAllocator&> UsedNames;
85 /// NextUniqueID - The next ID to dole out to an unnamed assembler temporary
87 unsigned NextUniqueID;
89 /// Instances of directional local labels.
90 DenseMap<unsigned, MCLabel *> Instances;
91 /// NextInstance() creates the next instance of the directional local label
92 /// for the LocalLabelVal and adds it to the map if needed.
93 unsigned NextInstance(unsigned LocalLabelVal);
94 /// GetInstance() gets the current instance of the directional local label
95 /// for the LocalLabelVal and adds it to the map if needed.
96 unsigned GetInstance(unsigned LocalLabelVal);
98 /// The file name of the log file from the environment variable
99 /// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique
100 /// directive is used or it is an error.
102 /// The stream that gets written to for the .secure_log_unique directive.
103 raw_ostream *SecureLog;
104 /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to
105 /// catch errors if .secure_log_unique appears twice without
106 /// .secure_log_reset appearing between them.
109 /// The compilation directory to use for DW_AT_comp_dir.
110 SmallString<128> CompilationDir;
112 /// The main file name if passed in explicitly.
113 std::string MainFileName;
115 /// The dwarf file and directory tables from the dwarf .file directive.
116 /// We now emit a line table for each compile unit. To reduce the prologue
117 /// size of each line table, the files and directories used by each compile
118 /// unit are separated.
119 std::map<unsigned, MCDwarfLineTable> MCDwarfLineTablesCUMap;
121 /// The current dwarf line information from the last dwarf .loc directive.
122 MCDwarfLoc CurrentDwarfLoc;
125 /// Generate dwarf debugging info for assembly source files.
126 bool GenDwarfForAssembly;
128 /// The current dwarf file number when generate dwarf debugging info for
129 /// assembly source files.
130 unsigned GenDwarfFileNumber;
132 /// The default initial text section that we generate dwarf debugging line
133 /// info for when generating dwarf assembly source files.
134 const MCSection *GenDwarfSection;
135 /// Symbols created for the start and end of this section.
136 MCSymbol *GenDwarfSectionStartSym, *GenDwarfSectionEndSym;
138 /// The information gathered from labels that will have dwarf label
139 /// entries when generating dwarf assembly source files.
140 std::vector<MCGenDwarfLabelEntry> MCGenDwarfLabelEntries;
142 /// The string to embed in the debug information for the compile unit, if
144 StringRef DwarfDebugFlags;
146 /// The string to embed in as the dwarf AT_producer for the compile unit, if
148 StringRef DwarfDebugProducer;
150 /// The maximum version of dwarf that we should emit.
151 uint16_t DwarfVersion;
153 /// Honor temporary labels, this is useful for debugging semantic
154 /// differences between temporary and non-temporary labels (primarily on
156 bool AllowTemporaryLabels;
158 /// The Compile Unit ID that we are currently processing.
159 unsigned DwarfCompileUnitID;
161 typedef std::pair<std::string, std::string> SectionGroupPair;
163 StringMap<const MCSectionMachO*> MachOUniquingMap;
164 std::map<SectionGroupPair, const MCSectionELF *> ELFUniquingMap;
165 std::map<SectionGroupPair, const MCSectionCOFF *> COFFUniquingMap;
167 /// Do automatic reset in destructor
170 MCSymbol *CreateSymbol(StringRef Name);
172 MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
176 explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI,
177 const MCObjectFileInfo *MOFI,
178 const SourceMgr *Mgr = nullptr, bool DoAutoReset = true);
181 const SourceMgr *getSourceManager() const { return SrcMgr; }
183 const MCAsmInfo *getAsmInfo() const { return MAI; }
185 const MCRegisterInfo *getRegisterInfo() const { return MRI; }
187 const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; }
189 void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; }
191 /// @name Module Lifetime Management
194 /// reset - return object to right after construction state to prepare
195 /// to process a new module
200 /// @name Symbol Management
203 /// CreateLinkerPrivateTempSymbol - Create and return a new linker temporary
204 /// symbol with a unique but unspecified name.
205 MCSymbol *CreateLinkerPrivateTempSymbol();
207 /// CreateTempSymbol - Create and return a new assembler temporary symbol
208 /// with a unique but unspecified name.
209 MCSymbol *CreateTempSymbol();
211 /// getUniqueSymbolID() - Return a unique identifier for use in constructing
213 unsigned getUniqueSymbolID() { return NextUniqueID++; }
215 /// Create the definition of a directional local symbol for numbered label
216 /// (used for "1:" definitions).
217 MCSymbol *CreateDirectionalLocalSymbol(unsigned LocalLabelVal);
219 /// Create and return a directional local symbol for numbered label (used
220 /// for "1b" or 1f" references).
221 MCSymbol *GetDirectionalLocalSymbol(unsigned LocalLabelVal, bool Before);
223 /// GetOrCreateSymbol - Lookup the symbol inside with the specified
224 /// @p Name. If it exists, return it. If not, create a forward
225 /// reference and return it.
227 /// @param Name - The symbol name, which must be unique across all symbols.
228 MCSymbol *GetOrCreateSymbol(StringRef Name);
229 MCSymbol *GetOrCreateSymbol(const Twine &Name);
231 /// LookupSymbol - Get the symbol for \p Name, or null.
232 MCSymbol *LookupSymbol(StringRef Name) const;
233 MCSymbol *LookupSymbol(const Twine &Name) const;
235 /// getSymbols - Get a reference for the symbol table for clients that
236 /// want to, for example, iterate over all symbols. 'const' because we
237 /// still want any modifications to the table itself to use the MCContext
239 const SymbolTable &getSymbols() const {
245 /// @name Section Management
248 /// getMachOSection - Return the MCSection for the specified mach-o section.
249 /// This requires the operands to be valid.
250 const MCSectionMachO *getMachOSection(StringRef Segment,
252 unsigned TypeAndAttributes,
255 const MCSectionMachO *getMachOSection(StringRef Segment,
257 unsigned TypeAndAttributes,
259 return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
262 const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
263 unsigned Flags, SectionKind Kind);
265 const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
266 unsigned Flags, SectionKind Kind,
267 unsigned EntrySize, StringRef Group);
269 void renameELFSection(const MCSectionELF *Section, StringRef Name);
271 const MCSectionELF *CreateELFGroupSection();
273 const MCSectionCOFF *getCOFFSection(StringRef Section,
274 unsigned Characteristics,
276 StringRef COMDATSymName, int Selection);
278 const MCSectionCOFF *getCOFFSection(StringRef Section,
279 unsigned Characteristics,
282 const MCSectionCOFF *getCOFFSection(StringRef Section);
286 /// @name Dwarf Management
289 /// \brief Get the compilation directory for DW_AT_comp_dir
290 /// This can be overridden by clients which want to control the reported
291 /// compilation directory and have it be something other than the current
292 /// working directory.
293 /// Returns an empty string if the current directory cannot be determined.
294 StringRef getCompilationDir() const { return CompilationDir; }
296 /// \brief Set the compilation directory for DW_AT_comp_dir
297 /// Override the default (CWD) compilation directory.
298 void setCompilationDir(StringRef S) { CompilationDir = S.str(); }
300 /// \brief Get the main file name for use in error messages and debug
301 /// info. This can be set to ensure we've got the correct file name
302 /// after preprocessing or for -save-temps.
303 const std::string &getMainFileName() const { return MainFileName; }
305 /// \brief Set the main file name and override the default.
306 void setMainFileName(StringRef S) { MainFileName = S; }
308 /// GetDwarfFile - creates an entry in the dwarf file and directory tables.
309 unsigned GetDwarfFile(StringRef Directory, StringRef FileName,
310 unsigned FileNumber, unsigned CUID);
312 bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0);
314 const std::map<unsigned, MCDwarfLineTable> &getMCDwarfLineTables() const {
315 return MCDwarfLineTablesCUMap;
318 MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) {
319 return MCDwarfLineTablesCUMap[CUID];
322 const MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) const {
323 auto I = MCDwarfLineTablesCUMap.find(CUID);
324 assert(I != MCDwarfLineTablesCUMap.end());
328 const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles(unsigned CUID = 0) {
329 return getMCDwarfLineTable(CUID).getMCDwarfFiles();
331 const SmallVectorImpl<std::string> &getMCDwarfDirs(unsigned CUID = 0) {
332 return getMCDwarfLineTable(CUID).getMCDwarfDirs();
335 bool hasMCLineSections() const {
336 for (const auto &Table : MCDwarfLineTablesCUMap)
337 if (!Table.second.getMCDwarfFiles().empty() || Table.second.getLabel())
341 unsigned getDwarfCompileUnitID() {
342 return DwarfCompileUnitID;
344 void setDwarfCompileUnitID(unsigned CUIndex) {
345 DwarfCompileUnitID = CUIndex;
347 void setMCLineTableCompilationDir(unsigned CUID, StringRef CompilationDir) {
348 getMCDwarfLineTable(CUID).setCompilationDir(CompilationDir);
351 /// setCurrentDwarfLoc - saves the information from the currently parsed
352 /// dwarf .loc directive and sets DwarfLocSeen. When the next instruction
353 /// is assembled an entry in the line number table with this information and
354 /// the address of the instruction will be created.
355 void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column,
356 unsigned Flags, unsigned Isa,
357 unsigned Discriminator) {
358 CurrentDwarfLoc.setFileNum(FileNum);
359 CurrentDwarfLoc.setLine(Line);
360 CurrentDwarfLoc.setColumn(Column);
361 CurrentDwarfLoc.setFlags(Flags);
362 CurrentDwarfLoc.setIsa(Isa);
363 CurrentDwarfLoc.setDiscriminator(Discriminator);
366 void ClearDwarfLocSeen() { DwarfLocSeen = false; }
368 bool getDwarfLocSeen() { return DwarfLocSeen; }
369 const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; }
371 bool getGenDwarfForAssembly() { return GenDwarfForAssembly; }
372 void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; }
373 unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; }
374 void setGenDwarfFileNumber(unsigned FileNumber) {
375 GenDwarfFileNumber = FileNumber;
377 const MCSection *getGenDwarfSection() { return GenDwarfSection; }
378 void setGenDwarfSection(const MCSection *Sec) { GenDwarfSection = Sec; }
379 MCSymbol *getGenDwarfSectionStartSym() { return GenDwarfSectionStartSym; }
380 void setGenDwarfSectionStartSym(MCSymbol *Sym) {
381 GenDwarfSectionStartSym = Sym;
383 MCSymbol *getGenDwarfSectionEndSym() { return GenDwarfSectionEndSym; }
384 void setGenDwarfSectionEndSym(MCSymbol *Sym) {
385 GenDwarfSectionEndSym = Sym;
387 const std::vector<MCGenDwarfLabelEntry> &getMCGenDwarfLabelEntries() const {
388 return MCGenDwarfLabelEntries;
390 void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E) {
391 MCGenDwarfLabelEntries.push_back(E);
394 void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; }
395 StringRef getDwarfDebugFlags() { return DwarfDebugFlags; }
397 void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; }
398 StringRef getDwarfDebugProducer() { return DwarfDebugProducer; }
400 void setDwarfVersion(uint16_t v) { DwarfVersion = v; }
401 uint16_t getDwarfVersion() const { return DwarfVersion; }
405 char *getSecureLogFile() { return SecureLogFile; }
406 raw_ostream *getSecureLog() { return SecureLog; }
407 bool getSecureLogUsed() { return SecureLogUsed; }
408 void setSecureLog(raw_ostream *Value) {
411 void setSecureLogUsed(bool Value) {
412 SecureLogUsed = Value;
415 void *Allocate(unsigned Size, unsigned Align = 8) {
416 return Allocator.Allocate(Size, Align);
418 void Deallocate(void *Ptr) {
421 // Unrecoverable error has occurred. Display the best diagnostic we can
422 // and bail via exit(1). For now, most MC backend errors are unrecoverable.
423 // FIXME: We should really do something about that.
424 LLVM_ATTRIBUTE_NORETURN void FatalError(SMLoc L, const Twine &Msg) const;
427 } // end namespace llvm
429 // operator new and delete aren't allowed inside namespaces.
430 // The throw specifications are mandated by the standard.
431 /// @brief Placement new for using the MCContext's allocator.
433 /// This placement form of operator new uses the MCContext's allocator for
434 /// obtaining memory. It is a non-throwing new, which means that it returns
435 /// null on error. (If that is what the allocator does. The current does, so if
436 /// this ever changes, this operator will have to be changed, too.)
437 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
439 /// // Default alignment (16)
440 /// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
441 /// // Specific alignment
442 /// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments);
444 /// Please note that you cannot use delete on the pointer; it must be
445 /// deallocated using an explicit destructor call followed by
446 /// @c Context.Deallocate(Ptr).
448 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
449 /// @param C The MCContext that provides the allocator.
450 /// @param Alignment The alignment of the allocated memory (if the underlying
451 /// allocator supports it).
452 /// @return The allocated memory. Could be NULL.
453 inline void *operator new(size_t Bytes, llvm::MCContext &C,
454 size_t Alignment = 16) throw () {
455 return C.Allocate(Bytes, Alignment);
457 /// @brief Placement delete companion to the new above.
459 /// This operator is just a companion to the new above. There is no way of
460 /// invoking it directly; see the new operator for more details. This operator
461 /// is called implicitly by the compiler if a placement new expression using
462 /// the MCContext throws in the object constructor.
463 inline void operator delete(void *Ptr, llvm::MCContext &C, size_t)
468 /// This placement form of operator new[] uses the MCContext's allocator for
469 /// obtaining memory. It is a non-throwing new[], which means that it returns
471 /// Usage looks like this (assuming there's an MCContext 'Context' in scope):
473 /// // Default alignment (16)
474 /// char *data = new (Context) char[10];
475 /// // Specific alignment
476 /// char *data = new (Context, 8) char[10];
478 /// Please note that you cannot use delete on the pointer; it must be
479 /// deallocated using an explicit destructor call followed by
480 /// @c Context.Deallocate(Ptr).
482 /// @param Bytes The number of bytes to allocate. Calculated by the compiler.
483 /// @param C The MCContext that provides the allocator.
484 /// @param Alignment The alignment of the allocated memory (if the underlying
485 /// allocator supports it).
486 /// @return The allocated memory. Could be NULL.
487 inline void *operator new[](size_t Bytes, llvm::MCContext& C,
488 size_t Alignment = 16) throw () {
489 return C.Allocate(Bytes, Alignment);
492 /// @brief Placement delete[] companion to the new[] above.
494 /// This operator is just a companion to the new[] above. There is no way of
495 /// invoking it directly; see the new[] operator for more details. This operator
496 /// is called implicitly by the compiler if a placement new[] expression using
497 /// the MCContext throws in the object constructor.
498 inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () {