1 //===-- llvm/MC/MCAsmInfo.h - Asm info --------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains a class to be used as the basis for target specific
10 // asm writers.  This class primarily takes care of global printing constants,
11 // which are used in very similar ways across all targets.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_MC_MCASMINFO_H
16 #define LLVM_MC_MCASMINFO_H
17 
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/MC/MCDirectives.h"
20 #include "llvm/MC/MCTargetOptions.h"
21 #include <vector>
22 
23 namespace llvm {
24 
25 class MCContext;
26 class MCCFIInstruction;
27 class MCExpr;
28 class MCSection;
29 class MCStreamer;
30 class MCSubtargetInfo;
31 class MCSymbol;
32 
33 namespace WinEH {
34 
35 enum class EncodingType {
36   Invalid, /// Invalid
37   Alpha,   /// Windows Alpha
38   Alpha64, /// Windows AXP64
39   ARM,     /// Windows NT (Windows on ARM)
40   CE,      /// Windows CE ARM, PowerPC, SH3, SH4
41   Itanium, /// Windows x64, Windows Itanium (IA-64)
42   X86,     /// Windows x86, uses no CFI, just EH tables
43   MIPS = Alpha,
44 };
45 
46 } // end namespace WinEH
47 
48 namespace LCOMM {
49 
50 enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment };
51 
52 } // end namespace LCOMM
53 
54 /// This class is intended to be used as a base class for asm
55 /// properties and features specific to the target.
56 class MCAsmInfo {
57 public:
58   /// Assembly character literal syntax types.
59   enum AsmCharLiteralSyntax {
60     ACLS_Unknown, /// Unknown; character literals not used by LLVM for this
61                   /// target.
62     ACLS_SingleQuotePrefix, /// The desired character is prefixed by a single
63                             /// quote, e.g., `'A`.
64   };
65 
66 protected:
67   //===------------------------------------------------------------------===//
68   // Properties to be set by the target writer, used to configure asm printer.
69   //
70 
71   /// Code pointer size in bytes.  Default is 4.
72   unsigned CodePointerSize = 4;
73 
74   /// Size of the stack slot reserved for callee-saved registers, in bytes.
75   /// Default is same as pointer size.
76   unsigned CalleeSaveStackSlotSize = 4;
77 
78   /// True if target is little endian.  Default is true.
79   bool IsLittleEndian = true;
80 
81   /// True if target stack grow up.  Default is false.
82   bool StackGrowsUp = false;
83 
84   /// True if this target has the MachO .subsections_via_symbols directive.
85   /// Default is false.
86   bool HasSubsectionsViaSymbols = false;
87 
88   /// True if this is a MachO target that supports the macho-specific .zerofill
89   /// directive for emitting BSS Symbols.  Default is false.
90   bool HasMachoZeroFillDirective = false;
91 
92   /// True if this is a MachO target that supports the macho-specific .tbss
93   /// directive for emitting thread local BSS Symbols.  Default is false.
94   bool HasMachoTBSSDirective = false;
95 
96   /// True if this is a non-GNU COFF target. The COFF port of the GNU linker
97   /// doesn't handle associative comdats in the way that we would like to use
98   /// them.
99   bool HasCOFFAssociativeComdats = false;
100 
101   /// True if this is a non-GNU COFF target. For GNU targets, we don't generate
102   /// constants into comdat sections.
103   bool HasCOFFComdatConstants = false;
104 
105   /// True if this is an XCOFF target that supports visibility attributes as
106   /// part of .global, .weak, .extern, and .comm. Default is false.
107   bool HasVisibilityOnlyWithLinkage = false;
108 
109   /// This is the maximum possible length of an instruction, which is needed to
110   /// compute the size of an inline asm.  Defaults to 4.
111   unsigned MaxInstLength = 4;
112 
113   /// Every possible instruction length is a multiple of this value.  Factored
114   /// out in .debug_frame and .debug_line.  Defaults to 1.
115   unsigned MinInstAlignment = 1;
116 
117   /// The '$' token, when not referencing an identifier or constant, refers to
118   /// the current PC.  Defaults to false.
119   bool DollarIsPC = false;
120 
121   /// Allow '.' token, when not referencing an identifier or constant, to refer
122   /// to the current PC. Defaults to true.
123   bool DotIsPC = true;
124 
125   /// Whether the '*' token refers to the current PC. This is used for the
126   /// HLASM dialect.
127   bool StarIsPC = false;
128 
129   /// This string, if specified, is used to separate instructions from each
130   /// other when on the same line.  Defaults to ';'
131   const char *SeparatorString;
132 
133   /// This indicates the comment string used by the assembler.  Defaults to
134   /// "#"
135   StringRef CommentString;
136 
137   /// This indicates whether the comment string is only accepted as a comment
138   /// at the beginning of statements. Defaults to false.
139   bool RestrictCommentStringToStartOfStatement = false;
140 
141   /// This indicates whether to allow additional "comment strings" to be lexed
142   /// as a comment. Setting this attribute to true, will ensure that C-style
143   /// line comments (// ..), C-style block comments (/* .. */), and "#" are
144   /// all treated as comments in addition to the string specified by the
145   /// CommentString attribute.
146   /// Default is true.
147   bool AllowAdditionalComments = true;
148 
149   /// Should we emit the '\t' as the starting indentation marker for GNU inline
150   /// asm statements. Defaults to true.
151   bool EmitGNUAsmStartIndentationMarker = true;
152 
153   /// This is appended to emitted labels.  Defaults to ":"
154   const char *LabelSuffix;
155 
156   /// Emit labels in purely upper case. Defaults to false.
157   bool EmitLabelsInUpperCase = false;
158 
159   // Print the EH begin symbol with an assignment. Defaults to false.
160   bool UseAssignmentForEHBegin = false;
161 
162   // Do we need to create a local symbol for .size?
163   bool NeedsLocalForSize = false;
164 
165   /// This prefix is used for globals like constant pool entries that are
166   /// completely private to the .s file and should not have names in the .o
167   /// file.  Defaults to "L"
168   StringRef PrivateGlobalPrefix;
169 
170   /// This prefix is used for labels for basic blocks. Defaults to the same as
171   /// PrivateGlobalPrefix.
172   StringRef PrivateLabelPrefix;
173 
174   /// This prefix is used for symbols that should be passed through the
175   /// assembler but be removed by the linker.  This is 'l' on Darwin, currently
176   /// used for some ObjC metadata.  The default of "" meast that for this system
177   /// a plain private symbol should be used.  Defaults to "".
178   StringRef LinkerPrivateGlobalPrefix;
179 
180   /// If these are nonempty, they contain a directive to emit before and after
181   /// an inline assembly statement.  Defaults to "#APP\n", "#NO_APP\n"
182   const char *InlineAsmStart;
183   const char *InlineAsmEnd;
184 
185   /// These are assembly directives that tells the assembler to interpret the
186   /// following instructions differently.  Defaults to ".code16", ".code32",
187   /// ".code64".
188   const char *Code16Directive;
189   const char *Code32Directive;
190   const char *Code64Directive;
191 
192   /// Which dialect of an assembler variant to use.  Defaults to 0
193   unsigned AssemblerDialect = 0;
194 
195   /// This is true if the assembler allows @ characters in symbol names.
196   /// Defaults to false.
197   bool AllowAtInName = false;
198 
199   /// This is true if the assembler allows the "?" character at the start of
200   /// of a string to be lexed as an AsmToken::Identifier.
201   /// If the AsmLexer determines that the string can be lexed as a possible
202   /// comment, setting this option will have no effect, and the string will
203   /// still be lexed as a comment.
204   bool AllowQuestionAtStartOfIdentifier = false;
205 
206   /// This is true if the assembler allows the "$" character at the start of
207   /// of a string to be lexed as an AsmToken::Identifier.
208   /// If the AsmLexer determines that the string can be lexed as a possible
209   /// comment, setting this option will have no effect, and the string will
210   /// still be lexed as a comment.
211   bool AllowDollarAtStartOfIdentifier = false;
212 
213   /// This is true if the assembler allows the "@" character at the start of
214   /// a string to be lexed as an AsmToken::Identifier.
215   /// If the AsmLexer determines that the string can be lexed as a possible
216   /// comment, setting this option will have no effect, and the string will
217   /// still be lexed as a comment.
218   bool AllowAtAtStartOfIdentifier = false;
219 
220   /// This is true if the assembler allows the "#" character at the start of
221   /// a string to be lexed as an AsmToken::Identifier.
222   /// If the AsmLexer determines that the string can be lexed as a possible
223   /// comment, setting this option will have no effect, and the string will
224   /// still be lexed as a comment.
225   bool AllowHashAtStartOfIdentifier = false;
226 
227   /// If this is true, symbol names with invalid characters will be printed in
228   /// quotes.
229   bool SupportsQuotedNames = true;
230 
231   /// This is true if data region markers should be printed as
232   /// ".data_region/.end_data_region" directives. If false, use "$d/$a" labels
233   /// instead.
234   bool UseDataRegionDirectives = false;
235 
236   /// True if .align is to be used for alignment. Only power-of-two
237   /// alignment is supported.
238   bool UseDotAlignForAlignment = false;
239 
240   /// True if the target supports LEB128 directives.
241   bool HasLEB128Directives = true;
242 
243   //===--- Data Emission Directives -------------------------------------===//
244 
245   /// This should be set to the directive used to get some number of zero (and
246   /// non-zero if supported by the directive) bytes emitted to the current
247   /// section. Common cases are "\t.zero\t" and "\t.space\t". Defaults to
248   /// "\t.zero\t"
249   const char *ZeroDirective;
250 
251   /// This should be set to true if the zero directive supports a value to emit
252   /// other than zero. If this is set to false, the Data*bitsDirective's will be
253   /// used to emit these bytes. Defaults to true.
254   bool ZeroDirectiveSupportsNonZeroValue = true;
255 
256   /// This directive allows emission of an ascii string with the standard C
257   /// escape characters embedded into it.  If a target doesn't support this, it
258   /// can be set to null. Defaults to "\t.ascii\t"
259   const char *AsciiDirective;
260 
261   /// If not null, this allows for special handling of zero terminated strings
262   /// on this target.  This is commonly supported as ".asciz".  If a target
263   /// doesn't support this, it can be set to null.  Defaults to "\t.asciz\t"
264   const char *AscizDirective;
265 
266   /// This directive accepts a comma-separated list of bytes for emission as a
267   /// string of bytes.  For targets that do not support this, it shall be set to
268   /// null.  Defaults to null.
269   const char *ByteListDirective = nullptr;
270 
271   /// This directive allows emission of a zero-terminated ascii string without
272   /// the standard C escape characters embedded into it.  If a target doesn't
273   /// support this, it can be set to null. Defaults to null.
274   const char *PlainStringDirective = nullptr;
275 
276   /// Form used for character literals in the assembly syntax.  Useful for
277   /// producing strings as byte lists.  If a target does not use or support
278   /// this, it shall be set to ACLS_Unknown.  Defaults to ACLS_Unknown.
279   AsmCharLiteralSyntax CharacterLiteralSyntax = ACLS_Unknown;
280 
281   /// These directives are used to output some unit of integer data to the
282   /// current section.  If a data directive is set to null, smaller data
283   /// directives will be used to emit the large sizes.  Defaults to "\t.byte\t",
284   /// "\t.short\t", "\t.long\t", "\t.quad\t"
285   const char *Data8bitsDirective;
286   const char *Data16bitsDirective;
287   const char *Data32bitsDirective;
288   const char *Data64bitsDirective;
289 
290   /// True if data directives support signed values
291   bool SupportsSignedData = true;
292 
293   /// If non-null, a directive that is used to emit a word which should be
294   /// relocated as a 64-bit GP-relative offset, e.g. .gpdword on Mips.  Defaults
295   /// to nullptr.
296   const char *GPRel64Directive = nullptr;
297 
298   /// If non-null, a directive that is used to emit a word which should be
299   /// relocated as a 32-bit GP-relative offset, e.g. .gpword on Mips or .gprel32
300   /// on Alpha.  Defaults to nullptr.
301   const char *GPRel32Directive = nullptr;
302 
303   /// If non-null, directives that are used to emit a word/dword which should
304   /// be relocated as a 32/64-bit DTP/TP-relative offset, e.g. .dtprelword/
305   /// .dtpreldword/.tprelword/.tpreldword on Mips.
306   const char *DTPRel32Directive = nullptr;
307   const char *DTPRel64Directive = nullptr;
308   const char *TPRel32Directive = nullptr;
309   const char *TPRel64Directive = nullptr;
310 
311   /// This is true if this target uses "Sun Style" syntax for section switching
312   /// ("#alloc,#write" etc) instead of the normal ELF syntax (,"a,w") in
313   /// .section directives.  Defaults to false.
314   bool SunStyleELFSectionSwitchSyntax = false;
315 
316   /// This is true if this target uses ELF '.section' directive before the
317   /// '.bss' one. It's used for PPC/Linux which doesn't support the '.bss'
318   /// directive only.  Defaults to false.
319   bool UsesELFSectionDirectiveForBSS = false;
320 
321   bool NeedsDwarfSectionOffsetDirective = false;
322 
323   //===--- Alignment Information ----------------------------------------===//
324 
325   /// If this is true (the default) then the asmprinter emits ".align N"
326   /// directives, where N is the number of bytes to align to.  Otherwise, it
327   /// emits ".align log2(N)", e.g. 3 to align to an 8 byte boundary.  Defaults
328   /// to true.
329   bool AlignmentIsInBytes = true;
330 
331   /// If non-zero, this is used to fill the executable space created as the
332   /// result of a alignment directive.  Defaults to 0
333   unsigned TextAlignFillValue = 0;
334 
335   //===--- Global Variable Emission Directives --------------------------===//
336 
337   /// This is the directive used to declare a global entity. Defaults to
338   /// ".globl".
339   const char *GlobalDirective;
340 
341   /// True if the expression
342   ///   .long f - g
343   /// uses a relocation but it can be suppressed by writing
344   ///   a = f - g
345   ///   .long a
346   bool SetDirectiveSuppressesReloc = false;
347 
348   /// False if the assembler requires that we use
349   /// \code
350   ///   Lc = a - b
351   ///   .long Lc
352   /// \endcode
353   //
354   /// instead of
355   //
356   /// \code
357   ///   .long a - b
358   /// \endcode
359   ///
360   ///  Defaults to true.
361   bool HasAggressiveSymbolFolding = true;
362 
363   /// True is .comm's and .lcomms optional alignment is to be specified in bytes
364   /// instead of log2(n).  Defaults to true.
365   bool COMMDirectiveAlignmentIsInBytes = true;
366 
367   /// Describes if the .lcomm directive for the target supports an alignment
368   /// argument and how it is interpreted.  Defaults to NoAlignment.
369   LCOMM::LCOMMType LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
370 
371   /// True if the target only has basename for .file directive. False if the
372   /// target also needs the directory along with the basename. Defaults to true.
373   bool HasBasenameOnlyForFileDirective = true;
374 
375   /// True if the target represents string constants as mostly raw characters in
376   /// paired double quotation with paired double quotation marks as the escape
377   /// mechanism to represent a double quotation mark within the string. Defaults
378   /// to false.
379   bool HasPairedDoubleQuoteStringConstants = false;
380 
381   // True if the target allows .align directives on functions. This is true for
382   // most targets, so defaults to true.
383   bool HasFunctionAlignment = true;
384 
385   /// True if the target has .type and .size directives, this is true for most
386   /// ELF targets.  Defaults to true.
387   bool HasDotTypeDotSizeDirective = true;
388 
389   /// True if the target has a single parameter .file directive, this is true
390   /// for ELF targets.  Defaults to true.
391   bool HasSingleParameterDotFile = true;
392 
393   /// True if the target has a four strings .file directive, strings seperated
394   /// by comma. Defaults to false.
395   bool HasFourStringsDotFile = false;
396 
397   /// True if the target has a .ident directive, this is true for ELF targets.
398   /// Defaults to false.
399   bool HasIdentDirective = false;
400 
401   /// True if this target supports the MachO .no_dead_strip directive.  Defaults
402   /// to false.
403   bool HasNoDeadStrip = false;
404 
405   /// True if this target supports the MachO .alt_entry directive.  Defaults to
406   /// false.
407   bool HasAltEntry = false;
408 
409   /// Used to declare a global as being a weak symbol. Defaults to ".weak".
410   const char *WeakDirective;
411 
412   /// This directive, if non-null, is used to declare a global as being a weak
413   /// undefined symbol.  Defaults to nullptr.
414   const char *WeakRefDirective = nullptr;
415 
416   /// True if we have a directive to declare a global as being a weak defined
417   /// symbol.  Defaults to false.
418   bool HasWeakDefDirective = false;
419 
420   /// True if we have a directive to declare a global as being a weak defined
421   /// symbol that can be hidden (unexported).  Defaults to false.
422   bool HasWeakDefCanBeHiddenDirective = false;
423 
424   /// True if we should mark symbols as global instead of weak, for
425   /// weak*/linkonce*, if the symbol has a comdat.
426   /// Defaults to false.
427   bool AvoidWeakIfComdat = false;
428 
429   /// This attribute, if not MCSA_Invalid, is used to declare a symbol as having
430   /// hidden visibility.  Defaults to MCSA_Hidden.
431   MCSymbolAttr HiddenVisibilityAttr = MCSA_Hidden;
432 
433   /// This attribute, if not MCSA_Invalid, is used to declare a symbol as having
434   /// exported visibility.  Defaults to MCSA_Exported.
435   MCSymbolAttr ExportedVisibilityAttr = MCSA_Exported;
436 
437   /// This attribute, if not MCSA_Invalid, is used to declare an undefined
438   /// symbol as having hidden visibility. Defaults to MCSA_Hidden.
439   MCSymbolAttr HiddenDeclarationVisibilityAttr = MCSA_Hidden;
440 
441   /// This attribute, if not MCSA_Invalid, is used to declare a symbol as having
442   /// protected visibility.  Defaults to MCSA_Protected
443   MCSymbolAttr ProtectedVisibilityAttr = MCSA_Protected;
444 
445   MCSymbolAttr MemtagAttr = MCSA_Memtag;
446 
447   //===--- Dwarf Emission Directives -----------------------------------===//
448 
449   /// True if target supports emission of debugging information.  Defaults to
450   /// false.
451   bool SupportsDebugInformation = false;
452 
453   /// Exception handling format for the target.  Defaults to None.
454   ExceptionHandling ExceptionsType = ExceptionHandling::None;
455 
456   /// True if target uses CFI unwind information for other purposes than EH
457   /// (debugging / sanitizers) when `ExceptionsType == ExceptionHandling::None`.
458   bool UsesCFIWithoutEH = false;
459 
460   /// Windows exception handling data (.pdata) encoding.  Defaults to Invalid.
461   WinEH::EncodingType WinEHEncodingType = WinEH::EncodingType::Invalid;
462 
463   /// True if Dwarf2 output generally uses relocations for references to other
464   /// .debug_* sections.
465   bool DwarfUsesRelocationsAcrossSections = true;
466 
467   /// True if DWARF FDE symbol reference relocations should be replaced by an
468   /// absolute difference.
469   bool DwarfFDESymbolsUseAbsDiff = false;
470 
471   /// True if the target supports generating the DWARF line table through using
472   /// the .loc/.file directives. Defaults to true.
473   bool UsesDwarfFileAndLocDirectives = true;
474 
475   /// True if DWARF `.file directory' directive syntax is used by
476   /// default.
477   bool EnableDwarfFileDirectoryDefault = true;
478 
479   /// True if the target needs the DWARF section length in the header (if any)
480   /// of the DWARF section in the assembly file. Defaults to true.
481   bool DwarfSectionSizeRequired = true;
482 
483   /// True if dwarf register numbers are printed instead of symbolic register
484   /// names in .cfi_* directives.  Defaults to false.
485   bool DwarfRegNumForCFI = false;
486 
487   /// True if target uses parens to indicate the symbol variant instead of @.
488   /// For example, foo(plt) instead of foo@plt.  Defaults to false.
489   bool UseParensForSymbolVariant = false;
490 
491   /// True if the target uses parens for symbol names starting with
492   /// '$' character to distinguish them from absolute names.
493   bool UseParensForDollarSignNames = true;
494 
495   /// True if the target supports flags in ".loc" directive, false if only
496   /// location is allowed.
497   bool SupportsExtendedDwarfLocDirective = true;
498 
499   //===--- Prologue State ----------------------------------------------===//
500 
501   std::vector<MCCFIInstruction> InitialFrameState;
502 
503   //===--- Integrated Assembler Information ----------------------------===//
504 
505   // Generated object files can use all ELF features supported by GNU ld of
506   // this binutils version and later. INT_MAX means all features can be used,
507   // regardless of GNU ld support. The default value is referenced by
508   // clang/Driver/Options.td.
509   std::pair<int, int> BinutilsVersion = {2, 26};
510 
511   /// Should we use the integrated assembler?
512   /// The integrated assembler should be enabled by default (by the
513   /// constructors) when failing to parse a valid piece of assembly (inline
514   /// or otherwise) is considered a bug. It may then be overridden after
515   /// construction (see LLVMTargetMachine::initAsmInfo()).
516   bool UseIntegratedAssembler;
517 
518   /// Use AsmParser to parse inlineAsm when UseIntegratedAssembler is not set.
519   bool ParseInlineAsmUsingAsmParser;
520 
521   /// Preserve Comments in assembly
522   bool PreserveAsmComments;
523 
524   /// Compress DWARF debug sections. Defaults to no compression.
525   DebugCompressionType CompressDebugSections = DebugCompressionType::None;
526 
527   /// True if the integrated assembler should interpret 'a >> b' constant
528   /// expressions as logical rather than arithmetic.
529   bool UseLogicalShr = true;
530 
531   // If true, emit GOTPCRELX/REX_GOTPCRELX instead of GOTPCREL, on
532   // X86_64 ELF.
533   bool RelaxELFRelocations = true;
534 
535   // If true, then the lexer and expression parser will support %neg(),
536   // %hi(), and similar unary operators.
537   bool HasMipsExpressions = false;
538 
539   // If true, use Motorola-style integers in Assembly (ex. $0ac).
540   bool UseMotorolaIntegers = false;
541 
542   // If true, emit function descriptor symbol on AIX.
543   bool NeedsFunctionDescriptors = false;
544 
545 public:
546   explicit MCAsmInfo();
547   virtual ~MCAsmInfo();
548 
549   /// Get the code pointer size in bytes.
550   unsigned getCodePointerSize() const { return CodePointerSize; }
551 
552   /// Get the callee-saved register stack slot
553   /// size in bytes.
554   unsigned getCalleeSaveStackSlotSize() const {
555     return CalleeSaveStackSlotSize;
556   }
557 
558   /// True if the target is little endian.
559   bool isLittleEndian() const { return IsLittleEndian; }
560 
561   /// True if target stack grow up.
562   bool isStackGrowthDirectionUp() const { return StackGrowsUp; }
563 
564   bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
565 
566   // Data directive accessors.
567 
568   const char *getData8bitsDirective() const { return Data8bitsDirective; }
569   const char *getData16bitsDirective() const { return Data16bitsDirective; }
570   const char *getData32bitsDirective() const { return Data32bitsDirective; }
571   const char *getData64bitsDirective() const { return Data64bitsDirective; }
572   bool supportsSignedData() const { return SupportsSignedData; }
573   const char *getGPRel64Directive() const { return GPRel64Directive; }
574   const char *getGPRel32Directive() const { return GPRel32Directive; }
575   const char *getDTPRel64Directive() const { return DTPRel64Directive; }
576   const char *getDTPRel32Directive() const { return DTPRel32Directive; }
577   const char *getTPRel64Directive() const { return TPRel64Directive; }
578   const char *getTPRel32Directive() const { return TPRel32Directive; }
579 
580   /// Targets can implement this method to specify a section to switch to if the
581   /// translation unit doesn't have any trampolines that require an executable
582   /// stack.
583   virtual MCSection *getNonexecutableStackSection(MCContext &Ctx) const {
584     return nullptr;
585   }
586 
587   /// True if the section is atomized using the symbols in it.
588   /// This is false if the section is not atomized at all (most ELF sections) or
589   /// if it is atomized based on its contents (MachO' __TEXT,__cstring for
590   /// example).
591   virtual bool isSectionAtomizableBySymbols(const MCSection &Section) const;
592 
593   virtual const MCExpr *getExprForPersonalitySymbol(const MCSymbol *Sym,
594                                                     unsigned Encoding,
595                                                     MCStreamer &Streamer) const;
596 
597   virtual const MCExpr *getExprForFDESymbol(const MCSymbol *Sym,
598                                             unsigned Encoding,
599                                             MCStreamer &Streamer) const;
600 
601   /// Return true if C is an acceptable character inside a symbol name.
602   virtual bool isAcceptableChar(char C) const;
603 
604   /// Return true if the identifier \p Name does not need quotes to be
605   /// syntactically correct.
606   virtual bool isValidUnquotedName(StringRef Name) const;
607 
608   /// Return true if the .section directive should be omitted when
609   /// emitting \p SectionName.  For example:
610   ///
611   /// shouldOmitSectionDirective(".text")
612   ///
613   /// returns false => .section .text,#alloc,#execinstr
614   /// returns true  => .text
615   virtual bool shouldOmitSectionDirective(StringRef SectionName) const;
616 
617   bool usesSunStyleELFSectionSwitchSyntax() const {
618     return SunStyleELFSectionSwitchSyntax;
619   }
620 
621   bool usesELFSectionDirectiveForBSS() const {
622     return UsesELFSectionDirectiveForBSS;
623   }
624 
625   bool needsDwarfSectionOffsetDirective() const {
626     return NeedsDwarfSectionOffsetDirective;
627   }
628 
629   // Accessors.
630 
631   bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
632   bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
633   bool hasCOFFAssociativeComdats() const { return HasCOFFAssociativeComdats; }
634   bool hasCOFFComdatConstants() const { return HasCOFFComdatConstants; }
635   bool hasVisibilityOnlyWithLinkage() const {
636     return HasVisibilityOnlyWithLinkage;
637   }
638 
639   /// Returns the maximum possible encoded instruction size in bytes. If \p STI
640   /// is null, this should be the maximum size for any subtarget.
641   virtual unsigned getMaxInstLength(const MCSubtargetInfo *STI = nullptr) const {
642     return MaxInstLength;
643   }
644 
645   unsigned getMinInstAlignment() const { return MinInstAlignment; }
646   bool getDollarIsPC() const { return DollarIsPC; }
647   bool getDotIsPC() const { return DotIsPC; }
648   bool getStarIsPC() const { return StarIsPC; }
649   const char *getSeparatorString() const { return SeparatorString; }
650 
651   /// This indicates the column (zero-based) at which asm comments should be
652   /// printed.
653   unsigned getCommentColumn() const { return 40; }
654 
655   StringRef getCommentString() const { return CommentString; }
656   bool getRestrictCommentStringToStartOfStatement() const {
657     return RestrictCommentStringToStartOfStatement;
658   }
659   bool shouldAllowAdditionalComments() const { return AllowAdditionalComments; }
660   bool getEmitGNUAsmStartIndentationMarker() const {
661     return EmitGNUAsmStartIndentationMarker;
662   }
663   const char *getLabelSuffix() const { return LabelSuffix; }
664   bool shouldEmitLabelsInUpperCase() const { return EmitLabelsInUpperCase; }
665 
666   bool useAssignmentForEHBegin() const { return UseAssignmentForEHBegin; }
667   bool needsLocalForSize() const { return NeedsLocalForSize; }
668   StringRef getPrivateGlobalPrefix() const { return PrivateGlobalPrefix; }
669   StringRef getPrivateLabelPrefix() const { return PrivateLabelPrefix; }
670 
671   bool hasLinkerPrivateGlobalPrefix() const {
672     return !LinkerPrivateGlobalPrefix.empty();
673   }
674 
675   StringRef getLinkerPrivateGlobalPrefix() const {
676     if (hasLinkerPrivateGlobalPrefix())
677       return LinkerPrivateGlobalPrefix;
678     return getPrivateGlobalPrefix();
679   }
680 
681   const char *getInlineAsmStart() const { return InlineAsmStart; }
682   const char *getInlineAsmEnd() const { return InlineAsmEnd; }
683   const char *getCode16Directive() const { return Code16Directive; }
684   const char *getCode32Directive() const { return Code32Directive; }
685   const char *getCode64Directive() const { return Code64Directive; }
686   unsigned getAssemblerDialect() const { return AssemblerDialect; }
687   bool doesAllowAtInName() const { return AllowAtInName; }
688   void setAllowAtInName(bool V) { AllowAtInName = V; }
689   bool doesAllowQuestionAtStartOfIdentifier() const {
690     return AllowQuestionAtStartOfIdentifier;
691   }
692   bool doesAllowAtAtStartOfIdentifier() const {
693     return AllowAtAtStartOfIdentifier;
694   }
695   bool doesAllowDollarAtStartOfIdentifier() const {
696     return AllowDollarAtStartOfIdentifier;
697   }
698   bool doesAllowHashAtStartOfIdentifier() const {
699     return AllowHashAtStartOfIdentifier;
700   }
701   bool supportsNameQuoting() const { return SupportsQuotedNames; }
702 
703   bool doesSupportDataRegionDirectives() const {
704     return UseDataRegionDirectives;
705   }
706 
707   bool useDotAlignForAlignment() const {
708     return UseDotAlignForAlignment;
709   }
710 
711   bool hasLEB128Directives() const { return HasLEB128Directives; }
712 
713   const char *getZeroDirective() const { return ZeroDirective; }
714   bool doesZeroDirectiveSupportNonZeroValue() const {
715     return ZeroDirectiveSupportsNonZeroValue;
716   }
717   const char *getAsciiDirective() const { return AsciiDirective; }
718   const char *getAscizDirective() const { return AscizDirective; }
719   const char *getByteListDirective() const { return ByteListDirective; }
720   const char *getPlainStringDirective() const { return PlainStringDirective; }
721   AsmCharLiteralSyntax characterLiteralSyntax() const {
722     return CharacterLiteralSyntax;
723   }
724   bool getAlignmentIsInBytes() const { return AlignmentIsInBytes; }
725   unsigned getTextAlignFillValue() const { return TextAlignFillValue; }
726   const char *getGlobalDirective() const { return GlobalDirective; }
727 
728   bool doesSetDirectiveSuppressReloc() const {
729     return SetDirectiveSuppressesReloc;
730   }
731 
732   bool hasAggressiveSymbolFolding() const { return HasAggressiveSymbolFolding; }
733 
734   bool getCOMMDirectiveAlignmentIsInBytes() const {
735     return COMMDirectiveAlignmentIsInBytes;
736   }
737 
738   LCOMM::LCOMMType getLCOMMDirectiveAlignmentType() const {
739     return LCOMMDirectiveAlignmentType;
740   }
741 
742   bool hasBasenameOnlyForFileDirective() const {
743     return HasBasenameOnlyForFileDirective;
744   }
745   bool hasPairedDoubleQuoteStringConstants() const {
746     return HasPairedDoubleQuoteStringConstants;
747   }
748   bool hasFunctionAlignment() const { return HasFunctionAlignment; }
749   bool hasDotTypeDotSizeDirective() const { return HasDotTypeDotSizeDirective; }
750   bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
751   bool hasFourStringsDotFile() const { return HasFourStringsDotFile; }
752   bool hasIdentDirective() const { return HasIdentDirective; }
753   bool hasNoDeadStrip() const { return HasNoDeadStrip; }
754   bool hasAltEntry() const { return HasAltEntry; }
755   const char *getWeakDirective() const { return WeakDirective; }
756   const char *getWeakRefDirective() const { return WeakRefDirective; }
757   bool hasWeakDefDirective() const { return HasWeakDefDirective; }
758 
759   bool hasWeakDefCanBeHiddenDirective() const {
760     return HasWeakDefCanBeHiddenDirective;
761   }
762 
763   bool avoidWeakIfComdat() const { return AvoidWeakIfComdat; }
764 
765   MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr; }
766 
767   MCSymbolAttr getExportedVisibilityAttr() const { return ExportedVisibilityAttr; }
768 
769   MCSymbolAttr getHiddenDeclarationVisibilityAttr() const {
770     return HiddenDeclarationVisibilityAttr;
771   }
772 
773   MCSymbolAttr getProtectedVisibilityAttr() const {
774     return ProtectedVisibilityAttr;
775   }
776 
777   MCSymbolAttr getMemtagAttr() const { return MemtagAttr; }
778 
779   bool doesSupportDebugInformation() const { return SupportsDebugInformation; }
780 
781   ExceptionHandling getExceptionHandlingType() const { return ExceptionsType; }
782   WinEH::EncodingType getWinEHEncodingType() const { return WinEHEncodingType; }
783 
784   void setExceptionsType(ExceptionHandling EH) {
785     ExceptionsType = EH;
786   }
787 
788   bool usesCFIWithoutEH() const {
789     return ExceptionsType == ExceptionHandling::None && UsesCFIWithoutEH;
790   }
791 
792   /// Returns true if the exception handling method for the platform uses call
793   /// frame information to unwind.
794   bool usesCFIForEH() const {
795     return (ExceptionsType == ExceptionHandling::DwarfCFI ||
796             ExceptionsType == ExceptionHandling::ARM || usesWindowsCFI());
797   }
798 
799   bool usesWindowsCFI() const {
800     return ExceptionsType == ExceptionHandling::WinEH &&
801            (WinEHEncodingType != WinEH::EncodingType::Invalid &&
802             WinEHEncodingType != WinEH::EncodingType::X86);
803   }
804 
805   bool doesDwarfUseRelocationsAcrossSections() const {
806     return DwarfUsesRelocationsAcrossSections;
807   }
808 
809   bool doDwarfFDESymbolsUseAbsDiff() const { return DwarfFDESymbolsUseAbsDiff; }
810   bool useDwarfRegNumForCFI() const { return DwarfRegNumForCFI; }
811   bool useParensForSymbolVariant() const { return UseParensForSymbolVariant; }
812   bool useParensForDollarSignNames() const {
813     return UseParensForDollarSignNames;
814   }
815   bool supportsExtendedDwarfLocDirective() const {
816     return SupportsExtendedDwarfLocDirective;
817   }
818 
819   bool usesDwarfFileAndLocDirectives() const {
820     return UsesDwarfFileAndLocDirectives;
821   }
822 
823   bool needsDwarfSectionSizeInHeader() const {
824     return DwarfSectionSizeRequired;
825   }
826 
827   bool enableDwarfFileDirectoryDefault() const {
828     return EnableDwarfFileDirectoryDefault;
829   }
830 
831   void addInitialFrameState(const MCCFIInstruction &Inst);
832 
833   const std::vector<MCCFIInstruction> &getInitialFrameState() const {
834     return InitialFrameState;
835   }
836 
837   void setBinutilsVersion(std::pair<int, int> Value) {
838     BinutilsVersion = Value;
839   }
840 
841   /// Return true if assembly (inline or otherwise) should be parsed.
842   bool useIntegratedAssembler() const { return UseIntegratedAssembler; }
843 
844   /// Return true if target want to use AsmParser to parse inlineasm.
845   bool parseInlineAsmUsingAsmParser() const {
846     return ParseInlineAsmUsingAsmParser;
847   }
848 
849   bool binutilsIsAtLeast(int Major, int Minor) const {
850     return BinutilsVersion >= std::make_pair(Major, Minor);
851   }
852 
853   /// Set whether assembly (inline or otherwise) should be parsed.
854   virtual void setUseIntegratedAssembler(bool Value) {
855     UseIntegratedAssembler = Value;
856   }
857 
858   /// Set whether target want to use AsmParser to parse inlineasm.
859   virtual void setParseInlineAsmUsingAsmParser(bool Value) {
860     ParseInlineAsmUsingAsmParser = Value;
861   }
862 
863   /// Return true if assembly (inline or otherwise) should be parsed.
864   bool preserveAsmComments() const { return PreserveAsmComments; }
865 
866   /// Set whether assembly (inline or otherwise) should be parsed.
867   virtual void setPreserveAsmComments(bool Value) {
868     PreserveAsmComments = Value;
869   }
870 
871   DebugCompressionType compressDebugSections() const {
872     return CompressDebugSections;
873   }
874 
875   void setCompressDebugSections(DebugCompressionType CompressDebugSections) {
876     this->CompressDebugSections = CompressDebugSections;
877   }
878 
879   bool shouldUseLogicalShr() const { return UseLogicalShr; }
880 
881   bool canRelaxRelocations() const { return RelaxELFRelocations; }
882   void setRelaxELFRelocations(bool V) { RelaxELFRelocations = V; }
883   bool hasMipsExpressions() const { return HasMipsExpressions; }
884   bool needsFunctionDescriptors() const { return NeedsFunctionDescriptors; }
885   bool shouldUseMotorolaIntegers() const { return UseMotorolaIntegers; }
886 };
887 
888 } // end namespace llvm
889 
890 #endif // LLVM_MC_MCASMINFO_H
891