1 //===-- llvm/MC/MCAsmInfo.h - Asm info --------------------------*- 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 // This file contains a class to be used as the basis for target specific
11 // asm writers. This class primarily takes care of global printing constants,
12 // which are used in very similar ways across all targets.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_TARGET_ASM_INFO_H
17 #define LLVM_TARGET_ASM_INFO_H
19 #include "llvm/MC/MachineLocation.h"
20 #include "llvm/MC/MCDirectives.h"
31 namespace ExceptionHandling {
32 enum ExceptionsType { None, DwarfCFI, SjLj, ARM, Win64 };
36 enum LCOMMType { None, NoAlignment, ByteAlignment };
40 enum OutputOrder { None, PriorityOrder, ReversePriorityOrder };
43 /// MCAsmInfo - This class is intended to be used as a base class for asm
44 /// properties and features specific to the target.
47 //===------------------------------------------------------------------===//
48 // Properties to be set by the target writer, used to configure asm printer.
51 /// PointerSize - Pointer size in bytes.
55 /// IsLittleEndian - True if target is little endian.
59 /// StackGrowsUp - True if target stack grow up.
63 /// HasSubsectionsViaSymbols - True if this target has the MachO
64 /// .subsections_via_symbols directive.
65 bool HasSubsectionsViaSymbols; // Default is false.
67 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
68 /// the macho-specific .zerofill directive for emitting BSS Symbols.
69 bool HasMachoZeroFillDirective; // Default is false.
71 /// HasMachoTBSSDirective - True if this is a MachO target that supports
72 /// the macho-specific .tbss directive for emitting thread local BSS Symbols
73 bool HasMachoTBSSDirective; // Default is false.
75 /// StructorOutputOrder - Whether the static ctor/dtor list should be output
76 /// in no particular order, in order of increasing priority or the reverse:
77 /// in order of decreasing priority (the default).
78 Structors::OutputOrder StructorOutputOrder; // Default is reverse order.
80 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
81 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
82 /// directive after the a static ctor/dtor list. This directive is only
83 /// emitted in Static relocation model.
84 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
86 /// LinkerRequiresNonEmptyDwarfLines - True if the linker has a bug and
87 /// requires that the debug_line section be of a minimum size. In practice
88 /// such a linker requires a non empty line sequence if a file is present.
89 bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
91 /// MaxInstLength - This is the maximum possible length of an instruction,
92 /// which is needed to compute the size of an inline asm.
93 unsigned MaxInstLength; // Defaults to 4.
95 /// PCSymbol - The symbol used to represent the current PC. Used in PC
96 /// relative expressions.
97 const char *PCSymbol; // Defaults to "$".
99 /// SeparatorString - This string, if specified, is used to separate
100 /// instructions from each other when on the same line.
101 const char *SeparatorString; // Defaults to ';'
103 /// CommentColumn - This indicates the comment num (zero-based) at
104 /// which asm comments should be printed.
105 unsigned CommentColumn; // Defaults to 40
107 /// CommentString - This indicates the comment character used by the
109 const char *CommentString; // Defaults to "#"
111 /// LabelSuffix - This is appended to emitted labels.
112 const char *LabelSuffix; // Defaults to ":"
114 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
115 /// onto all global symbols. This is often used for "_" or ".".
116 const char *GlobalPrefix; // Defaults to ""
118 /// PrivateGlobalPrefix - This prefix is used for globals like constant
119 /// pool entries that are completely private to the .s file and should not
120 /// have names in the .o file. This is often "." or "L".
121 const char *PrivateGlobalPrefix; // Defaults to "."
123 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
124 /// be passed through the assembler but be removed by the linker. This
125 /// is "l" on Darwin, currently used for some ObjC metadata.
126 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
128 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
129 /// emit before and after an inline assembly statement.
130 const char *InlineAsmStart; // Defaults to "#APP\n"
131 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
133 /// Code16Directive, Code32Directive, Code64Directive - These are assembly
134 /// directives that tells the assembler to interpret the following
135 /// instructions differently.
136 const char *Code16Directive; // Defaults to ".code16"
137 const char *Code32Directive; // Defaults to ".code32"
138 const char *Code64Directive; // Defaults to ".code64"
140 /// AssemblerDialect - Which dialect of an assembler variant to use.
141 unsigned AssemblerDialect; // Defaults to 0
143 /// AllowQuotesInName - This is true if the assembler allows for complex
144 /// symbol names to be surrounded in quotes. This defaults to false.
145 bool AllowQuotesInName;
147 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
148 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
149 bool AllowNameToStartWithDigit;
151 /// AllowPeriodsInName - This is true if the assembler allows periods in
152 /// symbol names. This defaults to true.
153 bool AllowPeriodsInName;
155 //===--- Data Emission Directives -------------------------------------===//
157 /// ZeroDirective - this should be set to the directive used to get some
158 /// number of zero bytes emitted to the current section. Common cases are
159 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
160 /// Data*bitsDirective's will be used to emit zero bytes.
161 const char *ZeroDirective; // Defaults to "\t.zero\t"
163 /// AsciiDirective - This directive allows emission of an ascii string with
164 /// the standard C escape characters embedded into it.
165 const char *AsciiDirective; // Defaults to "\t.ascii\t"
167 /// AscizDirective - If not null, this allows for special handling of
168 /// zero terminated strings on this target. This is commonly supported as
169 /// ".asciz". If a target doesn't support this, it can be set to null.
170 const char *AscizDirective; // Defaults to "\t.asciz\t"
172 /// DataDirectives - These directives are used to output some unit of
173 /// integer data to the current section. If a data directive is set to
174 /// null, smaller data directives will be used to emit the large sizes.
175 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
176 const char *Data16bitsDirective; // Defaults to "\t.short\t"
177 const char *Data32bitsDirective; // Defaults to "\t.long\t"
178 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
180 /// [Data|Code]Begin - These magic labels are used to marked a region as
181 /// data or code, and are used to provide additional information for
182 /// correct disassembly on targets that like to mix data and code within
183 /// a segment. These labels will be implicitly suffixed by the streamer
184 /// to give them unique names.
185 const char *DataBegin; // Defaults to "$d."
186 const char *CodeBegin; // Defaults to "$a."
187 const char *JT8Begin; // Defaults to "$a."
188 const char *JT16Begin; // Defaults to "$a."
189 const char *JT32Begin; // Defaults to "$a."
190 bool SupportsDataRegions;
192 /// GPRel32Directive - if non-null, a directive that is used to emit a word
193 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
194 /// on Mips or .gprel32 on Alpha.
195 const char *GPRel32Directive; // Defaults to NULL.
197 /// getDataASDirective - Return the directive that should be used to emit
198 /// data of the specified size to the specified numeric address space.
199 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
200 assert(AS != 0 && "Don't know the directives for default addr space");
204 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
205 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
206 /// normal ELF syntax (,"a,w") in .section directives.
207 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
209 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
210 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
211 /// which doesn't support the '.bss' directive only.
212 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
214 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
215 /// style mangling for functions with X86_StdCall/X86_FastCall calling
217 bool HasMicrosoftFastStdCallMangling; // Defaults to false.
219 //===--- Alignment Information ----------------------------------------===//
221 /// AlignDirective - The directive used to emit round up to an alignment
224 const char *AlignDirective; // Defaults to "\t.align\t"
226 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
227 /// emits ".align N" directives, where N is the number of bytes to align to.
228 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
230 bool AlignmentIsInBytes; // Defaults to true
232 /// TextAlignFillValue - If non-zero, this is used to fill the executable
233 /// space created as the result of a alignment directive.
234 unsigned TextAlignFillValue; // Defaults to 0
236 //===--- Global Variable Emission Directives --------------------------===//
238 /// GlobalDirective - This is the directive used to declare a global entity.
240 const char *GlobalDirective; // Defaults to NULL.
242 /// ExternDirective - This is the directive used to declare external
245 const char *ExternDirective; // Defaults to NULL.
247 /// HasSetDirective - True if the assembler supports the .set directive.
248 bool HasSetDirective; // Defaults to true.
250 /// HasAggressiveSymbolFolding - False if the assembler requires that we use
255 bool HasAggressiveSymbolFolding; // Defaults to true.
257 /// LCOMMDirectiveType - Describes if the target supports the .lcomm
258 /// directive and whether it has an alignment parameter.
259 LCOMM::LCOMMType LCOMMDirectiveType; // Defaults to LCOMM::None.
261 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional
262 /// alignment is to be specified in bytes instead of log2(n).
263 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
265 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
266 /// directives, this is true for most ELF targets.
267 bool HasDotTypeDotSizeDirective; // Defaults to true.
269 /// HasSingleParameterDotFile - True if the target has a single parameter
270 /// .file directive, this is true for ELF targets.
271 bool HasSingleParameterDotFile; // Defaults to true.
273 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
275 bool HasNoDeadStrip; // Defaults to false.
277 /// HasSymbolResolver - True if this target supports the MachO
278 /// .symbol_resolver directive.
279 bool HasSymbolResolver; // Defaults to false.
281 /// WeakRefDirective - This directive, if non-null, is used to declare a
282 /// global as being a weak undefined symbol.
283 const char *WeakRefDirective; // Defaults to NULL.
285 /// WeakDefDirective - This directive, if non-null, is used to declare a
286 /// global as being a weak defined symbol.
287 const char *WeakDefDirective; // Defaults to NULL.
289 /// LinkOnceDirective - This directive, if non-null is used to declare a
290 /// global as being a weak defined symbol. This is used on cygwin/mingw.
291 const char *LinkOnceDirective; // Defaults to NULL.
293 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
294 /// declare a symbol as having hidden visibility.
295 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
297 /// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid,
298 /// is used to declare an undefined symbol as having hidden visibility.
299 MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden.
302 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
303 /// to declare a symbol as having protected visibility.
304 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
306 //===--- Dwarf Emission Directives -----------------------------------===//
308 /// HasLEB128 - True if target asm supports leb128 directives.
309 bool HasLEB128; // Defaults to false.
311 /// SupportsDebugInformation - True if target supports emission of debugging
313 bool SupportsDebugInformation; // Defaults to false.
315 /// SupportsExceptionHandling - True if target supports exception handling.
316 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
318 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
319 /// encode inline subroutine information.
320 bool DwarfUsesInlineInfoSection; // Defaults to false.
322 /// DwarfSectionOffsetDirective - Special section offset directive.
323 const char* DwarfSectionOffsetDirective; // Defaults to NULL
325 /// DwarfRequiresRelocationForSectionOffset - True if we need to produce a
326 /// relocation when we want a section offset in dwarf.
327 bool DwarfRequiresRelocationForSectionOffset; // Defaults to true;
329 /// DwarfUsesLabelOffsetDifference - True if Dwarf2 output can
330 /// use EmitLabelOffsetDifference.
331 bool DwarfUsesLabelOffsetForRanges;
333 /// DwarfUsesRelocationsForStringPool - True if this Dwarf output must use
334 /// relocations to refer to entries in the string pool.
335 bool DwarfUsesRelocationsForStringPool;
337 /// DwarfRegNumForCFI - True if dwarf register numbers are printed
338 /// instead of symbolic register names in .cfi_* directives.
339 bool DwarfRegNumForCFI; // Defaults to false;
341 //===--- CBE Asm Translation Table -----------------------------------===//
343 const char *const *AsmTransCBE; // Defaults to empty
345 //===--- Prologue State ----------------------------------------------===//
347 std::vector<MachineMove> InitialFrameState;
350 explicit MCAsmInfo();
351 virtual ~MCAsmInfo();
353 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
354 static unsigned getSLEB128Size(int Value);
355 static unsigned getULEB128Size(unsigned Value);
357 /// getPointerSize - Get the pointer size in bytes.
358 unsigned getPointerSize() const {
362 /// islittleendian - True if the target is little endian.
363 bool isLittleEndian() const {
364 return IsLittleEndian;
367 /// isStackGrowthDirectionUp - True if target stack grow up.
368 bool isStackGrowthDirectionUp() const {
372 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
374 // Data directive accessors.
376 const char *getData8bitsDirective(unsigned AS = 0) const {
377 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
379 const char *getData16bitsDirective(unsigned AS = 0) const {
380 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
382 const char *getData32bitsDirective(unsigned AS = 0) const {
383 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
385 const char *getData64bitsDirective(unsigned AS = 0) const {
386 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
388 const char *getGPRel32Directive() const { return GPRel32Directive; }
390 /// [Code|Data]Begin label name accessors.
391 const char *getCodeBeginLabelName() const { return CodeBegin; }
392 const char *getDataBeginLabelName() const { return DataBegin; }
393 const char *getJumpTable8BeginLabelName() const { return JT8Begin; }
394 const char *getJumpTable16BeginLabelName() const { return JT16Begin; }
395 const char *getJumpTable32BeginLabelName() const { return JT32Begin; }
396 bool getSupportsDataRegions() const { return SupportsDataRegions; }
398 /// getNonexecutableStackSection - Targets can implement this method to
399 /// specify a section to switch to if the translation unit doesn't have any
400 /// trampolines that require an executable stack.
401 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
405 virtual const MCExpr *
406 getExprForPersonalitySymbol(const MCSymbol *Sym,
408 MCStreamer &Streamer) const;
411 getExprForFDESymbol(const MCSymbol *Sym,
413 MCStreamer &Streamer) const;
415 bool usesSunStyleELFSectionSwitchSyntax() const {
416 return SunStyleELFSectionSwitchSyntax;
419 bool usesELFSectionDirectiveForBSS() const {
420 return UsesELFSectionDirectiveForBSS;
423 bool hasMicrosoftFastStdCallMangling() const {
424 return HasMicrosoftFastStdCallMangling;
429 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
430 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
431 Structors::OutputOrder getStructorOutputOrder() const {
432 return StructorOutputOrder;
434 bool hasStaticCtorDtorReferenceInStaticMode() const {
435 return HasStaticCtorDtorReferenceInStaticMode;
437 bool getLinkerRequiresNonEmptyDwarfLines() const {
438 return LinkerRequiresNonEmptyDwarfLines;
440 unsigned getMaxInstLength() const {
441 return MaxInstLength;
443 const char *getPCSymbol() const {
446 const char *getSeparatorString() const {
447 return SeparatorString;
449 unsigned getCommentColumn() const {
450 return CommentColumn;
452 const char *getCommentString() const {
453 return CommentString;
455 const char *getLabelSuffix() const {
458 const char *getGlobalPrefix() const {
461 const char *getPrivateGlobalPrefix() const {
462 return PrivateGlobalPrefix;
464 const char *getLinkerPrivateGlobalPrefix() const {
465 return LinkerPrivateGlobalPrefix;
467 const char *getInlineAsmStart() const {
468 return InlineAsmStart;
470 const char *getInlineAsmEnd() const {
473 const char *getCode16Directive() const {
474 return Code16Directive;
476 const char *getCode32Directive() const {
477 return Code32Directive;
479 const char *getCode64Directive() const {
480 return Code64Directive;
482 unsigned getAssemblerDialect() const {
483 return AssemblerDialect;
485 bool doesAllowQuotesInName() const {
486 return AllowQuotesInName;
488 bool doesAllowNameToStartWithDigit() const {
489 return AllowNameToStartWithDigit;
491 bool doesAllowPeriodsInName() const {
492 return AllowPeriodsInName;
494 const char *getZeroDirective() const {
495 return ZeroDirective;
497 const char *getAsciiDirective() const {
498 return AsciiDirective;
500 const char *getAscizDirective() const {
501 return AscizDirective;
503 const char *getAlignDirective() const {
504 return AlignDirective;
506 bool getAlignmentIsInBytes() const {
507 return AlignmentIsInBytes;
509 unsigned getTextAlignFillValue() const {
510 return TextAlignFillValue;
512 const char *getGlobalDirective() const {
513 return GlobalDirective;
515 const char *getExternDirective() const {
516 return ExternDirective;
518 bool hasSetDirective() const { return HasSetDirective; }
519 bool hasAggressiveSymbolFolding() const {
520 return HasAggressiveSymbolFolding;
522 LCOMM::LCOMMType getLCOMMDirectiveType() const {
523 return LCOMMDirectiveType;
525 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
526 bool getCOMMDirectiveAlignmentIsInBytes() const {
527 return COMMDirectiveAlignmentIsInBytes;
529 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
530 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
531 bool hasSymbolResolver() const { return HasSymbolResolver; }
532 const char *getWeakRefDirective() const { return WeakRefDirective; }
533 const char *getWeakDefDirective() const { return WeakDefDirective; }
534 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
536 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
537 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const {
538 return HiddenDeclarationVisibilityAttr;
540 MCSymbolAttr getProtectedVisibilityAttr() const {
541 return ProtectedVisibilityAttr;
543 bool hasLEB128() const {
546 bool doesSupportDebugInformation() const {
547 return SupportsDebugInformation;
549 bool doesSupportExceptionHandling() const {
550 return ExceptionsType != ExceptionHandling::None;
552 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
553 return ExceptionsType;
555 bool isExceptionHandlingDwarf() const {
557 (ExceptionsType == ExceptionHandling::DwarfCFI ||
558 ExceptionsType == ExceptionHandling::ARM ||
559 ExceptionsType == ExceptionHandling::Win64);
561 bool doesDwarfUsesInlineInfoSection() const {
562 return DwarfUsesInlineInfoSection;
564 const char *getDwarfSectionOffsetDirective() const {
565 return DwarfSectionOffsetDirective;
567 bool doesDwarfRequireRelocationForSectionOffset() const {
568 return DwarfRequiresRelocationForSectionOffset;
570 bool doesDwarfUsesLabelOffsetForRanges() const {
571 return DwarfUsesLabelOffsetForRanges;
573 bool doesDwarfUseRelocationsForStringPool() const {
574 return DwarfUsesRelocationsForStringPool;
576 bool useDwarfRegNumForCFI() const {
577 return DwarfRegNumForCFI;
579 const char *const *getAsmCBE() const {
583 void addInitialFrameState(MCSymbol *label, const MachineLocation &D,
584 const MachineLocation &S) {
585 InitialFrameState.push_back(MachineMove(label, D, S));
587 const std::vector<MachineMove> &getInitialFrameState() const {
588 return InitialFrameState;