aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm12/include/llvm/MC/MCContext.h
blob: c8297d6088f3361c1049c1e42b025037db48aad8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
#pragma once

#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif

//===- MCContext.h - Machine Code Context -----------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCCONTEXT_H
#define LLVM_MC_MCCONTEXT_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/BinaryFormat/XCOFF.h"
#include "llvm/MC/MCAsmMacro.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCPseudoProbe.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MD5.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>

namespace llvm {

  class CodeViewContext;
  class MCAsmInfo;
  class MCLabel;
  class MCObjectFileInfo;
  class MCRegisterInfo;
  class MCSection;
  class MCSectionCOFF;
  class MCSectionELF;
  class MCSectionMachO;
  class MCSectionWasm;
  class MCSectionXCOFF;
  class MCStreamer;
  class MCSymbol;
  class MCSymbolELF;
  class MCSymbolWasm;
  class MCSymbolXCOFF;
  class SMLoc;
  class SourceMgr;

  /// Context object for machine code objects.  This class owns all of the
  /// sections that it creates.
  ///
  class MCContext {
  public:
    using SymbolTable = StringMap<MCSymbol *, BumpPtrAllocator &>;

  private:
    /// The SourceMgr for this object, if any.
    const SourceMgr *SrcMgr;

    /// The SourceMgr for inline assembly, if any.
    SourceMgr *InlineSrcMgr;

    /// The MCAsmInfo for this target.
    const MCAsmInfo *MAI;

    /// The MCRegisterInfo for this target.
    const MCRegisterInfo *MRI;

    /// The MCObjectFileInfo for this target.
    const MCObjectFileInfo *MOFI;

    std::unique_ptr<CodeViewContext> CVContext;

    /// Allocator object used for creating machine code objects.
    ///
    /// We use a bump pointer allocator to avoid the need to track all allocated
    /// objects.
    BumpPtrAllocator Allocator;

    SpecificBumpPtrAllocator<MCSectionCOFF> COFFAllocator;
    SpecificBumpPtrAllocator<MCSectionELF> ELFAllocator;
    SpecificBumpPtrAllocator<MCSectionMachO> MachOAllocator;
    SpecificBumpPtrAllocator<MCSectionWasm> WasmAllocator;
    SpecificBumpPtrAllocator<MCSectionXCOFF> XCOFFAllocator;
    SpecificBumpPtrAllocator<MCInst> MCInstAllocator;

    /// Bindings of names to symbols.
    SymbolTable Symbols;

    /// A mapping from a local label number and an instance count to a symbol.
    /// For example, in the assembly
    ///     1:
    ///     2:
    ///     1:
    /// We have three labels represented by the pairs (1, 0), (2, 0) and (1, 1)
    DenseMap<std::pair<unsigned, unsigned>, MCSymbol *> LocalSymbols;

    /// Keeps tracks of names that were used both for used declared and
    /// artificial symbols. The value is "true" if the name has been used for a
    /// non-section symbol (there can be at most one of those, plus an unlimited
    /// number of section symbols with the same name).
    StringMap<bool, BumpPtrAllocator &> UsedNames;

    /// Keeps track of labels that are used in inline assembly.
    SymbolTable InlineAsmUsedLabelNames;

    /// The next ID to dole out to an unnamed assembler temporary symbol with
    /// a given prefix.
    StringMap<unsigned> NextID;

    /// Instances of directional local labels.
    DenseMap<unsigned, MCLabel *> Instances;
    /// NextInstance() creates the next instance of the directional local label
    /// for the LocalLabelVal and adds it to the map if needed.
    unsigned NextInstance(unsigned LocalLabelVal);
    /// GetInstance() gets the current instance of the directional local label
    /// for the LocalLabelVal and adds it to the map if needed.
    unsigned GetInstance(unsigned LocalLabelVal);

    /// The file name of the log file from the environment variable
    /// AS_SECURE_LOG_FILE.  Which must be set before the .secure_log_unique
    /// directive is used or it is an error.
    char *SecureLogFile;
    /// The stream that gets written to for the .secure_log_unique directive.
    std::unique_ptr<raw_fd_ostream> SecureLog;
    /// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to
    /// catch errors if .secure_log_unique appears twice without
    /// .secure_log_reset appearing between them.
    bool SecureLogUsed = false;

    /// The compilation directory to use for DW_AT_comp_dir.
    SmallString<128> CompilationDir;

    /// Prefix replacement map for source file information.
    std::map<const std::string, const std::string> DebugPrefixMap;

    /// The main file name if passed in explicitly.
    std::string MainFileName;

    /// The dwarf file and directory tables from the dwarf .file directive.
    /// We now emit a line table for each compile unit. To reduce the prologue
    /// size of each line table, the files and directories used by each compile
    /// unit are separated.
    std::map<unsigned, MCDwarfLineTable> MCDwarfLineTablesCUMap;

    /// The current dwarf line information from the last dwarf .loc directive.
    MCDwarfLoc CurrentDwarfLoc;
    bool DwarfLocSeen = false;

    /// Generate dwarf debugging info for assembly source files.
    bool GenDwarfForAssembly = false;

    /// The current dwarf file number when generate dwarf debugging info for
    /// assembly source files.
    unsigned GenDwarfFileNumber = 0;

    /// Sections for generating the .debug_ranges and .debug_aranges sections.
    SetVector<MCSection *> SectionsForRanges;

    /// The information gathered from labels that will have dwarf label
    /// entries when generating dwarf assembly source files.
    std::vector<MCGenDwarfLabelEntry> MCGenDwarfLabelEntries;

    /// The string to embed in the debug information for the compile unit, if
    /// non-empty.
    StringRef DwarfDebugFlags;

    /// The string to embed in as the dwarf AT_producer for the compile unit, if
    /// non-empty.
    StringRef DwarfDebugProducer;

    /// The maximum version of dwarf that we should emit.
    uint16_t DwarfVersion = 4;

    /// The format of dwarf that we emit.
    dwarf::DwarfFormat DwarfFormat = dwarf::DWARF32;

    /// Honor temporary labels, this is useful for debugging semantic
    /// differences between temporary and non-temporary labels (primarily on
    /// Darwin).
    bool AllowTemporaryLabels = true;
    bool UseNamesOnTempLabels = false;

    /// The Compile Unit ID that we are currently processing.
    unsigned DwarfCompileUnitID = 0;

    /// A collection of MCPseudoProbe in the current module
    MCPseudoProbeTable PseudoProbeTable;

    // Sections are differentiated by the quadruple (section_name, group_name,
    // unique_id, link_to_symbol_name). Sections sharing the same quadruple are
    // combined into one section.
    struct ELFSectionKey {
      std::string SectionName;
      StringRef GroupName;
      StringRef LinkedToName;
      unsigned UniqueID;

      ELFSectionKey(StringRef SectionName, StringRef GroupName,
                    StringRef LinkedToName, unsigned UniqueID)
          : SectionName(SectionName), GroupName(GroupName),
            LinkedToName(LinkedToName), UniqueID(UniqueID) {}

      bool operator<(const ELFSectionKey &Other) const {
        if (SectionName != Other.SectionName)
          return SectionName < Other.SectionName;
        if (GroupName != Other.GroupName)
          return GroupName < Other.GroupName;
        if (int O = LinkedToName.compare(Other.LinkedToName))
          return O < 0;
        return UniqueID < Other.UniqueID;
      }
    };

    struct COFFSectionKey {
      std::string SectionName;
      StringRef GroupName;
      int SelectionKey;
      unsigned UniqueID;

      COFFSectionKey(StringRef SectionName, StringRef GroupName,
                     int SelectionKey, unsigned UniqueID)
          : SectionName(SectionName), GroupName(GroupName),
            SelectionKey(SelectionKey), UniqueID(UniqueID) {}

      bool operator<(const COFFSectionKey &Other) const {
        if (SectionName != Other.SectionName)
          return SectionName < Other.SectionName;
        if (GroupName != Other.GroupName)
          return GroupName < Other.GroupName;
        if (SelectionKey != Other.SelectionKey)
          return SelectionKey < Other.SelectionKey;
        return UniqueID < Other.UniqueID;
      }
    };

    struct WasmSectionKey {
      std::string SectionName;
      StringRef GroupName;
      unsigned UniqueID;

      WasmSectionKey(StringRef SectionName, StringRef GroupName,
                     unsigned UniqueID)
          : SectionName(SectionName), GroupName(GroupName), UniqueID(UniqueID) {
      }

      bool operator<(const WasmSectionKey &Other) const {
        if (SectionName != Other.SectionName)
          return SectionName < Other.SectionName;
        if (GroupName != Other.GroupName)
          return GroupName < Other.GroupName;
        return UniqueID < Other.UniqueID;
      }
    };

    struct XCOFFSectionKey {
      std::string SectionName;
      XCOFF::StorageMappingClass MappingClass;

      XCOFFSectionKey(StringRef SectionName,
                      XCOFF::StorageMappingClass MappingClass)
          : SectionName(SectionName), MappingClass(MappingClass) {}

      bool operator<(const XCOFFSectionKey &Other) const {
        return std::tie(SectionName, MappingClass) <
               std::tie(Other.SectionName, Other.MappingClass);
      }
    };

    StringMap<MCSectionMachO *> MachOUniquingMap;
    std::map<ELFSectionKey, MCSectionELF *> ELFUniquingMap;
    std::map<COFFSectionKey, MCSectionCOFF *> COFFUniquingMap;
    std::map<WasmSectionKey, MCSectionWasm *> WasmUniquingMap;
    std::map<XCOFFSectionKey, MCSectionXCOFF *> XCOFFUniquingMap;
    StringMap<bool> RelSecNames;

    SpecificBumpPtrAllocator<MCSubtargetInfo> MCSubtargetAllocator;

    /// Do automatic reset in destructor
    bool AutoReset;

    MCTargetOptions const *TargetOptions;

    bool HadError = false;

    MCSymbol *createSymbolImpl(const StringMapEntry<bool> *Name,
                               bool CanBeUnnamed);
    MCSymbol *createSymbol(StringRef Name, bool AlwaysAddSuffix,
                           bool IsTemporary);

    MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
                                                unsigned Instance);

    MCSectionELF *createELFSectionImpl(StringRef Section, unsigned Type,
                                       unsigned Flags, SectionKind K,
                                       unsigned EntrySize,
                                       const MCSymbolELF *Group,
                                       unsigned UniqueID,
                                       const MCSymbolELF *LinkedToSym);

    MCSymbolXCOFF *createXCOFFSymbolImpl(const StringMapEntry<bool> *Name,
                                         bool IsTemporary);

    /// Map of currently defined macros.
    StringMap<MCAsmMacro> MacroMap;

    struct ELFEntrySizeKey {
      std::string SectionName;
      unsigned Flags;
      unsigned EntrySize;

      ELFEntrySizeKey(StringRef SectionName, unsigned Flags, unsigned EntrySize)
          : SectionName(SectionName), Flags(Flags), EntrySize(EntrySize) {}

      bool operator<(const ELFEntrySizeKey &Other) const {
        if (SectionName != Other.SectionName)
          return SectionName < Other.SectionName;
        if ((Flags & ELF::SHF_STRINGS) != (Other.Flags & ELF::SHF_STRINGS))
          return Other.Flags & ELF::SHF_STRINGS;
        return EntrySize < Other.EntrySize;
      }
    };

    // Symbols must be assigned to a section with a compatible entry
    // size. This map is used to assign unique IDs to sections to
    // distinguish between sections with identical names but incompatible entry
    // sizes. This can occur when a symbol is explicitly assigned to a
    // section, e.g. via __attribute__((section("myname"))).
    std::map<ELFEntrySizeKey, unsigned> ELFEntrySizeMap;

    // This set is used to record the generic mergeable section names seen.
    // These are sections that are created as mergeable e.g. .debug_str. We need
    // to avoid assigning non-mergeable symbols to these sections. It is used
    // to prevent non-mergeable symbols being explicitly assigned  to mergeable
    // sections (e.g. via _attribute_((section("myname")))).
    DenseSet<StringRef> ELFSeenGenericMergeableSections;

  public:
    explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI,
                       const MCObjectFileInfo *MOFI,
                       const SourceMgr *Mgr = nullptr,
                       MCTargetOptions const *TargetOpts = nullptr,
                       bool DoAutoReset = true);
    MCContext(const MCContext &) = delete;
    MCContext &operator=(const MCContext &) = delete;
    ~MCContext();

    const SourceMgr *getSourceManager() const { return SrcMgr; }

    void setInlineSourceManager(SourceMgr *SM) { InlineSrcMgr = SM; }

    const MCAsmInfo *getAsmInfo() const { return MAI; }

    const MCRegisterInfo *getRegisterInfo() const { return MRI; }

    const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; }

    CodeViewContext &getCVContext();

    void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; }
    void setUseNamesOnTempLabels(bool Value) { UseNamesOnTempLabels = Value; }

    /// \name Module Lifetime Management
    /// @{

    /// reset - return object to right after construction state to prepare
    /// to process a new module
    void reset();

    /// @}

    /// \name McInst Management

    /// Create and return a new MC instruction.
    MCInst *createMCInst();

    /// \name Symbol Management
    /// @{

    /// Create and return a new linker temporary symbol with a unique but
    /// unspecified name.
    MCSymbol *createLinkerPrivateTempSymbol();

    /// Create a temporary symbol with a unique name. The name will be omitted
    /// in the symbol table if UseNamesOnTempLabels is false (default except
    /// MCAsmStreamer). The overload without Name uses an unspecified name.
    MCSymbol *createTempSymbol();
    MCSymbol *createTempSymbol(const Twine &Name, bool AlwaysAddSuffix = true);

    /// Create a temporary symbol with a unique name whose name cannot be
    /// omitted in the symbol table. This is rarely used.
    MCSymbol *createNamedTempSymbol();
    MCSymbol *createNamedTempSymbol(const Twine &Name);

    /// Create the definition of a directional local symbol for numbered label
    /// (used for "1:" definitions).
    MCSymbol *createDirectionalLocalSymbol(unsigned LocalLabelVal);

    /// Create and return a directional local symbol for numbered label (used
    /// for "1b" or 1f" references).
    MCSymbol *getDirectionalLocalSymbol(unsigned LocalLabelVal, bool Before);

    /// Lookup the symbol inside with the specified \p Name.  If it exists,
    /// return it.  If not, create a forward reference and return it.
    ///
    /// \param Name - The symbol name, which must be unique across all symbols.
    MCSymbol *getOrCreateSymbol(const Twine &Name);

    /// Gets a symbol that will be defined to the final stack offset of a local
    /// variable after codegen.
    ///
    /// \param Idx - The index of a local variable passed to \@llvm.localescape.
    MCSymbol *getOrCreateFrameAllocSymbol(StringRef FuncName, unsigned Idx);

    MCSymbol *getOrCreateParentFrameOffsetSymbol(StringRef FuncName);

    MCSymbol *getOrCreateLSDASymbol(StringRef FuncName);

    /// Get the symbol for \p Name, or null.
    MCSymbol *lookupSymbol(const Twine &Name) const;

    /// Set value for a symbol.
    void setSymbolValue(MCStreamer &Streamer, StringRef Sym, uint64_t Val);

    /// getSymbols - Get a reference for the symbol table for clients that
    /// want to, for example, iterate over all symbols. 'const' because we
    /// still want any modifications to the table itself to use the MCContext
    /// APIs.
    const SymbolTable &getSymbols() const { return Symbols; }

    /// isInlineAsmLabel - Return true if the name is a label referenced in
    /// inline assembly.
    MCSymbol *getInlineAsmLabel(StringRef Name) const {
      return InlineAsmUsedLabelNames.lookup(Name);
    }

    /// registerInlineAsmLabel - Records that the name is a label referenced in
    /// inline assembly.
    void registerInlineAsmLabel(MCSymbol *Sym);

    /// @}

    /// \name Section Management
    /// @{

    enum : unsigned {
      /// Pass this value as the UniqueID during section creation to get the
      /// generic section with the given name and characteristics. The usual
      /// sections such as .text use this ID.
      GenericSectionID = ~0U
    };

    /// Return the MCSection for the specified mach-o section.  This requires
    /// the operands to be valid.
    MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
                                    unsigned TypeAndAttributes,
                                    unsigned Reserved2, SectionKind K,
                                    const char *BeginSymName = nullptr);

    MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
                                    unsigned TypeAndAttributes, SectionKind K,
                                    const char *BeginSymName = nullptr) {
      return getMachOSection(Segment, Section, TypeAndAttributes, 0, K,
                             BeginSymName);
    }

    MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
                                unsigned Flags) {
      return getELFSection(Section, Type, Flags, 0, "");
    }

    MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
                                unsigned Flags, unsigned EntrySize,
                                const Twine &Group) {
      return getELFSection(Section, Type, Flags, EntrySize, Group,
                           MCSection::NonUniqueID, nullptr);
    }

    MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
                                unsigned Flags, unsigned EntrySize,
                                const Twine &Group, unsigned UniqueID,
                                const MCSymbolELF *LinkedToSym);

    MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
                                unsigned Flags, unsigned EntrySize,
                                const MCSymbolELF *Group, unsigned UniqueID,
                                const MCSymbolELF *LinkedToSym);

    /// Get a section with the provided group identifier. This section is
    /// named by concatenating \p Prefix with '.' then \p Suffix. The \p Type
    /// describes the type of the section and \p Flags are used to further
    /// configure this named section.
    MCSectionELF *getELFNamedSection(const Twine &Prefix, const Twine &Suffix,
                                     unsigned Type, unsigned Flags,
                                     unsigned EntrySize = 0);

    MCSectionELF *createELFRelSection(const Twine &Name, unsigned Type,
                                      unsigned Flags, unsigned EntrySize,
                                      const MCSymbolELF *Group,
                                      const MCSectionELF *RelInfoSection);

    void renameELFSection(MCSectionELF *Section, StringRef Name);

    MCSectionELF *createELFGroupSection(const MCSymbolELF *Group);

    void recordELFMergeableSectionInfo(StringRef SectionName, unsigned Flags,
                                       unsigned UniqueID, unsigned EntrySize);

    bool isELFImplicitMergeableSectionNamePrefix(StringRef Name);

    bool isELFGenericMergeableSection(StringRef Name);

    Optional<unsigned> getELFUniqueIDForEntsize(StringRef SectionName,
                                                unsigned Flags,
                                                unsigned EntrySize);

    MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
                                  SectionKind Kind, StringRef COMDATSymName,
                                  int Selection,
                                  unsigned UniqueID = GenericSectionID,
                                  const char *BeginSymName = nullptr);

    MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
                                  SectionKind Kind,
                                  const char *BeginSymName = nullptr);

    /// Gets or creates a section equivalent to Sec that is associated with the
    /// section containing KeySym. For example, to create a debug info section
    /// associated with an inline function, pass the normal debug info section
    /// as Sec and the function symbol as KeySym.
    MCSectionCOFF *
    getAssociativeCOFFSection(MCSectionCOFF *Sec, const MCSymbol *KeySym,
                              unsigned UniqueID = GenericSectionID);

    MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K) {
      return getWasmSection(Section, K, nullptr);
    }

    MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
                                  const char *BeginSymName) {
      return getWasmSection(Section, K, "", ~0, BeginSymName);
    }

    MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
                                  const Twine &Group, unsigned UniqueID) {
      return getWasmSection(Section, K, Group, UniqueID, nullptr);
    }

    MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
                                  const Twine &Group, unsigned UniqueID,
                                  const char *BeginSymName);

    MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
                                  const MCSymbolWasm *Group, unsigned UniqueID,
                                  const char *BeginSymName);

    MCSectionXCOFF *getXCOFFSection(StringRef Section,
                                    XCOFF::StorageMappingClass MappingClass,
                                    XCOFF::SymbolType CSectType, SectionKind K,
                                    bool MultiSymbolsAllowed = false,
                                    const char *BeginSymName = nullptr);

    // Create and save a copy of STI and return a reference to the copy.
    MCSubtargetInfo &getSubtargetCopy(const MCSubtargetInfo &STI);

    /// @}

    /// \name Dwarf Management
    /// @{

    /// Get the compilation directory for DW_AT_comp_dir
    /// The compilation directory should be set with \c setCompilationDir before
    /// calling this function. If it is unset, an empty string will be returned.
    StringRef getCompilationDir() const { return CompilationDir; }

    /// Set the compilation directory for DW_AT_comp_dir
    void setCompilationDir(StringRef S) { CompilationDir = S.str(); }

    /// Add an entry to the debug prefix map.
    void addDebugPrefixMapEntry(const std::string &From, const std::string &To);

    // Remaps all debug directory paths in-place as per the debug prefix map.
    void RemapDebugPaths();

    /// Get the main file name for use in error messages and debug
    /// info. This can be set to ensure we've got the correct file name
    /// after preprocessing or for -save-temps.
    const std::string &getMainFileName() const { return MainFileName; }

    /// Set the main file name and override the default.
    void setMainFileName(StringRef S) { MainFileName = std::string(S); }

    /// Creates an entry in the dwarf file and directory tables.
    Expected<unsigned> getDwarfFile(StringRef Directory, StringRef FileName,
                                    unsigned FileNumber,
                                    Optional<MD5::MD5Result> Checksum,
                                    Optional<StringRef> Source, unsigned CUID);

    bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0);

    const std::map<unsigned, MCDwarfLineTable> &getMCDwarfLineTables() const {
      return MCDwarfLineTablesCUMap;
    }

    MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) {
      return MCDwarfLineTablesCUMap[CUID];
    }

    const MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) const {
      auto I = MCDwarfLineTablesCUMap.find(CUID);
      assert(I != MCDwarfLineTablesCUMap.end());
      return I->second;
    }

    const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles(unsigned CUID = 0) {
      return getMCDwarfLineTable(CUID).getMCDwarfFiles();
    }

    const SmallVectorImpl<std::string> &getMCDwarfDirs(unsigned CUID = 0) {
      return getMCDwarfLineTable(CUID).getMCDwarfDirs();
    }

    unsigned getDwarfCompileUnitID() { return DwarfCompileUnitID; }

    void setDwarfCompileUnitID(unsigned CUIndex) {
      DwarfCompileUnitID = CUIndex;
    }

    /// Specifies the "root" file and directory of the compilation unit.
    /// These are "file 0" and "directory 0" in DWARF v5.
    void setMCLineTableRootFile(unsigned CUID, StringRef CompilationDir,
                                StringRef Filename,
                                Optional<MD5::MD5Result> Checksum,
                                Optional<StringRef> Source) {
      getMCDwarfLineTable(CUID).setRootFile(CompilationDir, Filename, Checksum,
                                            Source);
    }

    /// Reports whether MD5 checksum usage is consistent (all-or-none).
    bool isDwarfMD5UsageConsistent(unsigned CUID) const {
      return getMCDwarfLineTable(CUID).isMD5UsageConsistent();
    }

    /// Saves the information from the currently parsed dwarf .loc directive
    /// and sets DwarfLocSeen.  When the next instruction is assembled an entry
    /// in the line number table with this information and the address of the
    /// instruction will be created.
    void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column,
                            unsigned Flags, unsigned Isa,
                            unsigned Discriminator) {
      CurrentDwarfLoc.setFileNum(FileNum);
      CurrentDwarfLoc.setLine(Line);
      CurrentDwarfLoc.setColumn(Column);
      CurrentDwarfLoc.setFlags(Flags);
      CurrentDwarfLoc.setIsa(Isa);
      CurrentDwarfLoc.setDiscriminator(Discriminator);
      DwarfLocSeen = true;
    }

    void clearDwarfLocSeen() { DwarfLocSeen = false; }

    bool getDwarfLocSeen() { return DwarfLocSeen; }
    const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; }

    bool getGenDwarfForAssembly() { return GenDwarfForAssembly; }
    void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; }
    unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; }

    void setGenDwarfFileNumber(unsigned FileNumber) {
      GenDwarfFileNumber = FileNumber;
    }

    /// Specifies information about the "root file" for assembler clients
    /// (e.g., llvm-mc). Assumes compilation dir etc. have been set up.
    void setGenDwarfRootFile(StringRef FileName, StringRef Buffer);

    const SetVector<MCSection *> &getGenDwarfSectionSyms() {
      return SectionsForRanges;
    }

    bool addGenDwarfSection(MCSection *Sec) {
      return SectionsForRanges.insert(Sec);
    }

    void finalizeDwarfSections(MCStreamer &MCOS);

    const std::vector<MCGenDwarfLabelEntry> &getMCGenDwarfLabelEntries() const {
      return MCGenDwarfLabelEntries;
    }

    void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E) {
      MCGenDwarfLabelEntries.push_back(E);
    }

    void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; }
    StringRef getDwarfDebugFlags() { return DwarfDebugFlags; }

    void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; }
    StringRef getDwarfDebugProducer() { return DwarfDebugProducer; }

    void setDwarfFormat(dwarf::DwarfFormat f) { DwarfFormat = f; }
    dwarf::DwarfFormat getDwarfFormat() const { return DwarfFormat; }

    void setDwarfVersion(uint16_t v) { DwarfVersion = v; }
    uint16_t getDwarfVersion() const { return DwarfVersion; }

    /// @}

    char *getSecureLogFile() { return SecureLogFile; }
    raw_fd_ostream *getSecureLog() { return SecureLog.get(); }

    void setSecureLog(std::unique_ptr<raw_fd_ostream> Value) {
      SecureLog = std::move(Value);
    }

    bool getSecureLogUsed() { return SecureLogUsed; }
    void setSecureLogUsed(bool Value) { SecureLogUsed = Value; }

    void *allocate(unsigned Size, unsigned Align = 8) {
      return Allocator.Allocate(Size, Align);
    }

    void deallocate(void *Ptr) {}

    bool hadError() { return HadError; }
    void reportError(SMLoc L, const Twine &Msg);
    void reportWarning(SMLoc L, const Twine &Msg);
    // Unrecoverable error has occurred. Display the best diagnostic we can
    // and bail via exit(1). For now, most MC backend errors are unrecoverable.
    // FIXME: We should really do something about that.
    LLVM_ATTRIBUTE_NORETURN void reportFatalError(SMLoc L,
                                                  const Twine &Msg);

    const MCAsmMacro *lookupMacro(StringRef Name) {
      StringMap<MCAsmMacro>::iterator I = MacroMap.find(Name);
      return (I == MacroMap.end()) ? nullptr : &I->getValue();
    }

    void defineMacro(StringRef Name, MCAsmMacro Macro) {
      MacroMap.insert(std::make_pair(Name, std::move(Macro)));
    }

    void undefineMacro(StringRef Name) { MacroMap.erase(Name); }

    MCPseudoProbeTable &getMCPseudoProbeTable() { return PseudoProbeTable; }
  };

} // end namespace llvm

// operator new and delete aren't allowed inside namespaces.
// The throw specifications are mandated by the standard.
/// Placement new for using the MCContext's allocator.
///
/// This placement form of operator new uses the MCContext's allocator for
/// obtaining memory. It is a non-throwing new, which means that it returns
/// null on error. (If that is what the allocator does. The current does, so if
/// this ever changes, this operator will have to be changed, too.)
/// Usage looks like this (assuming there's an MCContext 'Context' in scope):
/// \code
/// // Default alignment (8)
/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
/// // Specific alignment
/// IntegerLiteral *Ex2 = new (Context, 4) IntegerLiteral(arguments);
/// \endcode
/// Please note that you cannot use delete on the pointer; it must be
/// deallocated using an explicit destructor call followed by
/// \c Context.Deallocate(Ptr).
///
/// \param Bytes The number of bytes to allocate. Calculated by the compiler.
/// \param C The MCContext that provides the allocator.
/// \param Alignment The alignment of the allocated memory (if the underlying
///                  allocator supports it).
/// \return The allocated memory. Could be NULL.
inline void *operator new(size_t Bytes, llvm::MCContext &C,
                          size_t Alignment = 8) noexcept {
  return C.allocate(Bytes, Alignment);
}
/// Placement delete companion to the new above.
///
/// This operator is just a companion to the new above. There is no way of
/// invoking it directly; see the new operator for more details. This operator
/// is called implicitly by the compiler if a placement new expression using
/// the MCContext throws in the object constructor.
inline void operator delete(void *Ptr, llvm::MCContext &C, size_t) noexcept {
  C.deallocate(Ptr);
}

/// This placement form of operator new[] uses the MCContext's allocator for
/// obtaining memory. It is a non-throwing new[], which means that it returns
/// null on error.
/// Usage looks like this (assuming there's an MCContext 'Context' in scope):
/// \code
/// // Default alignment (8)
/// char *data = new (Context) char[10];
/// // Specific alignment
/// char *data = new (Context, 4) char[10];
/// \endcode
/// Please note that you cannot use delete on the pointer; it must be
/// deallocated using an explicit destructor call followed by
/// \c Context.Deallocate(Ptr).
///
/// \param Bytes The number of bytes to allocate. Calculated by the compiler.
/// \param C The MCContext that provides the allocator.
/// \param Alignment The alignment of the allocated memory (if the underlying
///                  allocator supports it).
/// \return The allocated memory. Could be NULL.
inline void *operator new[](size_t Bytes, llvm::MCContext &C,
                            size_t Alignment = 8) noexcept {
  return C.allocate(Bytes, Alignment);
}

/// Placement delete[] companion to the new[] above.
///
/// This operator is just a companion to the new[] above. There is no way of
/// invoking it directly; see the new[] operator for more details. This operator
/// is called implicitly by the compiler if a placement new[] expression using
/// the MCContext throws in the object constructor.
inline void operator delete[](void *Ptr, llvm::MCContext &C) noexcept {
  C.deallocate(Ptr);
}

#endif // LLVM_MC_MCCONTEXT_H

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif