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_MC_MCASMINFO_H
17 #define LLVM_MC_MCASMINFO_H
19 #include "llvm/MC/MCDirectives.h"
20 #include "llvm/MC/MCDwarf.h"
21 #include "llvm/MC/MachineLocation.h"
32 namespace ExceptionHandling {
33 enum ExceptionsType { None, DwarfCFI, SjLj, ARM, Win64 };
37 enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment };
40 /// MCAsmInfo - This class is intended to be used as a base class for asm
41 /// properties and features specific to the target.
44 //===------------------------------------------------------------------===//
45 // Properties to be set by the target writer, used to configure asm printer.
48 /// PointerSize - Pointer size in bytes.
52 /// CalleeSaveStackSlotSize - Size of the stack slot reserved for
53 /// callee-saved registers, in bytes.
54 /// Default is same as pointer size.
55 unsigned CalleeSaveStackSlotSize;
57 /// IsLittleEndian - True if target is little endian.
61 /// StackGrowsUp - True if target stack grow up.
65 /// HasSubsectionsViaSymbols - True if this target has the MachO
66 /// .subsections_via_symbols directive.
67 bool HasSubsectionsViaSymbols; // Default is false.
69 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
70 /// the macho-specific .zerofill directive for emitting BSS Symbols.
71 bool HasMachoZeroFillDirective; // Default is false.
73 /// HasMachoTBSSDirective - True if this is a MachO target that supports
74 /// the macho-specific .tbss directive for emitting thread local BSS Symbols
75 bool HasMachoTBSSDirective; // Default is false.
77 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
78 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
79 /// directive after the a static ctor/dtor list. This directive is only
80 /// emitted in Static relocation model.
81 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
83 /// LinkerRequiresNonEmptyDwarfLines - True if the linker has a bug and
84 /// requires that the debug_line section be of a minimum size. In practice
85 /// such a linker requires a non-empty line sequence if a file is present.
86 bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
88 /// MaxInstLength - This is the maximum possible length of an instruction,
89 /// which is needed to compute the size of an inline asm.
90 unsigned MaxInstLength; // Defaults to 4.
92 /// MinInstAlignment - Every possible instruction length is a multiple of
93 /// this value. Factored out in .debug_frame and .debug_line.
94 unsigned MinInstAlignment; // Defaults to 1.
96 /// DollarIsPC - The '$' token, when not referencing an identifier or
97 /// constant, refers to the current PC.
98 bool DollarIsPC; // Defaults to false.
100 /// SeparatorString - This string, if specified, is used to separate
101 /// instructions from each other when on the same line.
102 const char *SeparatorString; // Defaults to ';'
104 /// CommentString - This indicates the comment character used by the
106 const char *CommentString; // Defaults to "#"
108 /// LabelSuffix - This is appended to emitted labels.
109 const char *LabelSuffix; // Defaults to ":"
111 /// LabelSuffix - This is appended to emitted labels.
112 const char *DebugLabelSuffix; // Defaults to ":"
114 /// This prefix is used for globals like constant pool entries that are
115 /// completely private to the .s file and should not have names in the .o
117 const char *PrivateGlobalPrefix; // Defaults to "L"
119 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
120 /// emit before and after an inline assembly statement.
121 const char *InlineAsmStart; // Defaults to "#APP\n"
122 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
124 /// Code16Directive, Code32Directive, Code64Directive - These are assembly
125 /// directives that tells the assembler to interpret the following
126 /// instructions differently.
127 const char *Code16Directive; // Defaults to ".code16"
128 const char *Code32Directive; // Defaults to ".code32"
129 const char *Code64Directive; // Defaults to ".code64"
131 /// AssemblerDialect - Which dialect of an assembler variant to use.
132 unsigned AssemblerDialect; // Defaults to 0
134 /// \brief This is true if the assembler allows @ characters in symbol
135 /// names. Defaults to false.
138 /// UseDataRegionDirectives - This is true if data region markers should
139 /// be printed as ".data_region/.end_data_region" directives. If false,
140 /// use "$d/$a" labels instead.
141 bool UseDataRegionDirectives;
143 //===--- Data Emission Directives -------------------------------------===//
145 /// ZeroDirective - this should be set to the directive used to get some
146 /// number of zero bytes emitted to the current section. Common cases are
147 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
148 /// Data*bitsDirective's will be used to emit zero bytes.
149 const char *ZeroDirective; // Defaults to "\t.zero\t"
151 /// AsciiDirective - This directive allows emission of an ascii string with
152 /// the standard C escape characters embedded into it.
153 const char *AsciiDirective; // Defaults to "\t.ascii\t"
155 /// AscizDirective - If not null, this allows for special handling of
156 /// zero terminated strings on this target. This is commonly supported as
157 /// ".asciz". If a target doesn't support this, it can be set to null.
158 const char *AscizDirective; // Defaults to "\t.asciz\t"
160 /// DataDirectives - These directives are used to output some unit of
161 /// integer data to the current section. If a data directive is set to
162 /// null, smaller data directives will be used to emit the large sizes.
163 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
164 const char *Data16bitsDirective; // Defaults to "\t.short\t"
165 const char *Data32bitsDirective; // Defaults to "\t.long\t"
166 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
168 /// GPRel64Directive - if non-null, a directive that is used to emit a word
169 /// which should be relocated as a 64-bit GP-relative offset, e.g. .gpdword
171 const char *GPRel64Directive; // Defaults to NULL.
173 /// GPRel32Directive - if non-null, a directive that is used to emit a word
174 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
175 /// on Mips or .gprel32 on Alpha.
176 const char *GPRel32Directive; // Defaults to NULL.
178 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
179 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
180 /// normal ELF syntax (,"a,w") in .section directives.
181 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
183 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
184 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
185 /// which doesn't support the '.bss' directive only.
186 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
188 bool NeedsDwarfSectionOffsetDirective;
190 //===--- Alignment Information ----------------------------------------===//
192 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
193 /// emits ".align N" directives, where N is the number of bytes to align to.
194 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
196 bool AlignmentIsInBytes; // Defaults to true
198 /// TextAlignFillValue - If non-zero, this is used to fill the executable
199 /// space created as the result of a alignment directive.
200 unsigned TextAlignFillValue; // Defaults to 0
202 //===--- Global Variable Emission Directives --------------------------===//
204 /// GlobalDirective - This is the directive used to declare a global entity.
206 const char *GlobalDirective; // Defaults to NULL.
208 /// HasSetDirective - True if the assembler supports the .set directive.
209 bool HasSetDirective; // Defaults to true.
211 /// HasAggressiveSymbolFolding - False if the assembler requires that we use
216 bool HasAggressiveSymbolFolding; // Defaults to true.
218 /// COMMDirectiveAlignmentIsInBytes - True is .comm's and .lcomms optional
219 /// alignment is to be specified in bytes instead of log2(n).
220 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
222 /// LCOMMDirectiveAlignment - Describes if the .lcomm directive for the
223 /// target supports an alignment argument and how it is interpreted.
224 LCOMM::LCOMMType LCOMMDirectiveAlignmentType; // Defaults to NoAlignment.
226 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
227 /// directives, this is true for most ELF targets.
228 bool HasDotTypeDotSizeDirective; // Defaults to true.
230 /// HasSingleParameterDotFile - True if the target has a single parameter
231 /// .file directive, this is true for ELF targets.
232 bool HasSingleParameterDotFile; // Defaults to true.
234 /// hasIdentDirective - True if the target has a .ident directive, this is
235 /// true for ELF targets.
236 bool HasIdentDirective; // Defaults to false.
238 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
240 bool HasNoDeadStrip; // Defaults to false.
242 /// WeakRefDirective - This directive, if non-null, is used to declare a
243 /// global as being a weak undefined symbol.
244 const char *WeakRefDirective; // Defaults to NULL.
246 /// True if we have a directive to declare a global as being a weak
248 bool HasWeakDefDirective; // Defaults to false.
250 /// True if we have a directive to declare a global as being a weak
251 /// defined symbol that can be hidden (unexported).
252 bool HasWeakDefCanBeHiddenDirective; // Defaults to false.
254 /// True if we have a .linkonce directive. This is used on cygwin/mingw.
255 bool HasLinkOnceDirective; // Defaults to false.
257 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
258 /// declare a symbol as having hidden visibility.
259 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
261 /// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid,
262 /// is used to declare an undefined symbol as having hidden visibility.
263 MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden.
266 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
267 /// to declare a symbol as having protected visibility.
268 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
270 //===--- Dwarf Emission Directives -----------------------------------===//
272 /// HasLEB128 - True if target asm supports leb128 directives.
273 bool HasLEB128; // Defaults to false.
275 /// SupportsDebugInformation - True if target supports emission of debugging
277 bool SupportsDebugInformation; // Defaults to false.
279 /// SupportsExceptionHandling - True if target supports exception handling.
280 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
282 /// DwarfUsesRelocationsAcrossSections - True if Dwarf2 output generally
283 /// uses relocations for references to other .debug_* sections.
284 bool DwarfUsesRelocationsAcrossSections;
286 /// DwarfFDESymbolsUseAbsDiff - true if DWARF FDE symbol reference
287 /// relocations should be replaced by an absolute difference.
288 bool DwarfFDESymbolsUseAbsDiff;
290 /// DwarfRegNumForCFI - True if dwarf register numbers are printed
291 /// instead of symbolic register names in .cfi_* directives.
292 bool DwarfRegNumForCFI; // Defaults to false;
294 /// UseParensForSymbolVariant - True if target uses parens to indicate the
295 /// symbol variant instead of @. For example, foo(plt) instead of foo@plt.
296 bool UseParensForSymbolVariant; // Defaults to false;
298 //===--- Prologue State ----------------------------------------------===//
300 std::vector<MCCFIInstruction> InitialFrameState;
302 //===--- Integrated Assembler State ----------------------------------===//
303 /// Should we use the integrated assembler?
304 /// The integrated assembler should be enabled by default (by the
305 /// constructors) when failing to parse a valid piece of assembly (inline
306 /// or otherwise) is considered a bug. It may then be overridden after
307 /// construction (see LLVMTargetMachine::initAsmInfo()).
308 bool UseIntegratedAssembler;
310 /// Compress DWARF debug sections. Defaults to false.
311 bool CompressDebugSections;
314 explicit MCAsmInfo();
315 virtual ~MCAsmInfo();
317 /// getPointerSize - Get the pointer size in bytes.
318 unsigned getPointerSize() const {
322 /// getCalleeSaveStackSlotSize - Get the callee-saved register stack slot
324 unsigned getCalleeSaveStackSlotSize() const {
325 return CalleeSaveStackSlotSize;
328 /// isLittleEndian - True if the target is little endian.
329 bool isLittleEndian() const {
330 return IsLittleEndian;
333 /// isStackGrowthDirectionUp - True if target stack grow up.
334 bool isStackGrowthDirectionUp() const {
338 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
340 // Data directive accessors.
342 const char *getData8bitsDirective() const {
343 return Data8bitsDirective;
345 const char *getData16bitsDirective() const {
346 return Data16bitsDirective;
348 const char *getData32bitsDirective() const {
349 return Data32bitsDirective;
351 const char *getData64bitsDirective() const {
352 return Data64bitsDirective;
354 const char *getGPRel64Directive() const { return GPRel64Directive; }
355 const char *getGPRel32Directive() const { return GPRel32Directive; }
357 /// getNonexecutableStackSection - Targets can implement this method to
358 /// specify a section to switch to if the translation unit doesn't have any
359 /// trampolines that require an executable stack.
360 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
364 virtual const MCExpr *
365 getExprForPersonalitySymbol(const MCSymbol *Sym,
367 MCStreamer &Streamer) const;
369 virtual const MCExpr *
370 getExprForFDESymbol(const MCSymbol *Sym,
372 MCStreamer &Streamer) const;
374 bool usesSunStyleELFSectionSwitchSyntax() const {
375 return SunStyleELFSectionSwitchSyntax;
378 bool usesELFSectionDirectiveForBSS() const {
379 return UsesELFSectionDirectiveForBSS;
382 bool needsDwarfSectionOffsetDirective() const {
383 return NeedsDwarfSectionOffsetDirective;
388 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
389 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
390 bool hasStaticCtorDtorReferenceInStaticMode() const {
391 return HasStaticCtorDtorReferenceInStaticMode;
393 bool getLinkerRequiresNonEmptyDwarfLines() const {
394 return LinkerRequiresNonEmptyDwarfLines;
396 unsigned getMaxInstLength() const {
397 return MaxInstLength;
399 unsigned getMinInstAlignment() const {
400 return MinInstAlignment;
402 bool getDollarIsPC() const {
405 const char *getSeparatorString() const {
406 return SeparatorString;
409 /// This indicates the column (zero-based) at which asm comments should be
411 unsigned getCommentColumn() const {
415 const char *getCommentString() const {
416 return CommentString;
418 const char *getLabelSuffix() const {
422 const char *getDebugLabelSuffix() const {
423 return DebugLabelSuffix;
425 const char *getPrivateGlobalPrefix() const {
426 return PrivateGlobalPrefix;
428 const char *getInlineAsmStart() const {
429 return InlineAsmStart;
431 const char *getInlineAsmEnd() const {
434 const char *getCode16Directive() const {
435 return Code16Directive;
437 const char *getCode32Directive() const {
438 return Code32Directive;
440 const char *getCode64Directive() const {
441 return Code64Directive;
443 unsigned getAssemblerDialect() const {
444 return AssemblerDialect;
446 bool doesAllowAtInName() const {
447 return AllowAtInName;
449 bool doesSupportDataRegionDirectives() const {
450 return UseDataRegionDirectives;
452 const char *getZeroDirective() const {
453 return ZeroDirective;
455 const char *getAsciiDirective() const {
456 return AsciiDirective;
458 const char *getAscizDirective() const {
459 return AscizDirective;
461 bool getAlignmentIsInBytes() const {
462 return AlignmentIsInBytes;
464 unsigned getTextAlignFillValue() const {
465 return TextAlignFillValue;
467 const char *getGlobalDirective() const {
468 return GlobalDirective;
470 bool hasSetDirective() const { return HasSetDirective; }
471 bool hasAggressiveSymbolFolding() const {
472 return HasAggressiveSymbolFolding;
474 bool getCOMMDirectiveAlignmentIsInBytes() const {
475 return COMMDirectiveAlignmentIsInBytes;
477 LCOMM::LCOMMType getLCOMMDirectiveAlignmentType() const {
478 return LCOMMDirectiveAlignmentType;
480 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
481 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
482 bool hasIdentDirective() const { return HasIdentDirective; }
483 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
484 const char *getWeakRefDirective() const { return WeakRefDirective; }
485 bool hasWeakDefDirective() const { return HasWeakDefDirective; }
486 bool hasWeakDefCanBeHiddenDirective() const {
487 return HasWeakDefCanBeHiddenDirective;
489 bool hasLinkOnceDirective() const { return HasLinkOnceDirective; }
491 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
492 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const {
493 return HiddenDeclarationVisibilityAttr;
495 MCSymbolAttr getProtectedVisibilityAttr() const {
496 return ProtectedVisibilityAttr;
498 bool hasLEB128() const {
501 bool doesSupportDebugInformation() const {
502 return SupportsDebugInformation;
504 bool doesSupportExceptionHandling() const {
505 return ExceptionsType != ExceptionHandling::None;
507 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
508 return ExceptionsType;
510 bool isExceptionHandlingDwarf() const {
512 (ExceptionsType == ExceptionHandling::DwarfCFI ||
513 ExceptionsType == ExceptionHandling::ARM ||
514 ExceptionsType == ExceptionHandling::Win64);
516 bool doesDwarfUseRelocationsAcrossSections() const {
517 return DwarfUsesRelocationsAcrossSections;
519 bool doDwarfFDESymbolsUseAbsDiff() const {
520 return DwarfFDESymbolsUseAbsDiff;
522 bool useDwarfRegNumForCFI() const {
523 return DwarfRegNumForCFI;
525 bool useParensForSymbolVariant() const {
526 return UseParensForSymbolVariant;
529 void addInitialFrameState(const MCCFIInstruction &Inst) {
530 InitialFrameState.push_back(Inst);
533 const std::vector<MCCFIInstruction> &getInitialFrameState() const {
534 return InitialFrameState;
537 /// Return true if assembly (inline or otherwise) should be parsed.
538 bool useIntegratedAssembler() const { return UseIntegratedAssembler; }
540 /// Set whether assembly (inline or otherwise) should be parsed.
541 virtual void setUseIntegratedAssembler(bool Value) {
542 UseIntegratedAssembler = Value;
545 bool compressDebugSections() const { return CompressDebugSections; }
547 void setCompressDebugSections(bool CompressDebugSections) {
548 this->CompressDebugSections = CompressDebugSections;