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 };
39 /// MCAsmInfo - This class is intended to be used as a base class for asm
40 /// properties and features specific to the target.
43 //===------------------------------------------------------------------===//
44 // Properties to be set by the target writer, used to configure asm printer.
47 /// PointerSize - Pointer size in bytes.
51 /// IsLittleEndian - True if target is little endian.
55 /// StackGrowsUp - True if target stack grow up.
59 /// HasSubsectionsViaSymbols - True if this target has the MachO
60 /// .subsections_via_symbols directive.
61 bool HasSubsectionsViaSymbols; // Default is false.
63 /// HasMachoZeroFillDirective - True if this is a MachO target that supports
64 /// the macho-specific .zerofill directive for emitting BSS Symbols.
65 bool HasMachoZeroFillDirective; // Default is false.
67 /// HasMachoTBSSDirective - True if this is a MachO target that supports
68 /// the macho-specific .tbss directive for emitting thread local BSS Symbols
69 bool HasMachoTBSSDirective; // Default is false.
71 /// HasStaticCtorDtorReferenceInStaticMode - True if the compiler should
72 /// emit a ".reference .constructors_used" or ".reference .destructors_used"
73 /// directive after the a static ctor/dtor list. This directive is only
74 /// emitted in Static relocation model.
75 bool HasStaticCtorDtorReferenceInStaticMode; // Default is false.
77 /// LinkerRequiresNonEmptyDwarfLines - True if the linker has a bug and
78 /// requires that the debug_line section be of a minimum size. In practice
79 /// such a linker requires a non empty line sequence if a file is present.
80 bool LinkerRequiresNonEmptyDwarfLines; // Default to false.
82 /// MaxInstLength - This is the maximum possible length of an instruction,
83 /// which is needed to compute the size of an inline asm.
84 unsigned MaxInstLength; // Defaults to 4.
86 /// PCSymbol - The symbol used to represent the current PC. Used in PC
87 /// relative expressions.
88 const char *PCSymbol; // Defaults to "$".
90 /// SeparatorString - This string, if specified, is used to separate
91 /// instructions from each other when on the same line.
92 const char *SeparatorString; // Defaults to ';'
94 /// CommentColumn - This indicates the comment num (zero-based) at
95 /// which asm comments should be printed.
96 unsigned CommentColumn; // Defaults to 40
98 /// CommentString - This indicates the comment character used by the
100 const char *CommentString; // Defaults to "#"
102 /// LabelSuffix - This is appended to emitted labels.
103 const char *LabelSuffix; // Defaults to ":"
105 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
106 /// onto all global symbols. This is often used for "_" or ".".
107 const char *GlobalPrefix; // Defaults to ""
109 /// PrivateGlobalPrefix - This prefix is used for globals like constant
110 /// pool entries that are completely private to the .s file and should not
111 /// have names in the .o file. This is often "." or "L".
112 const char *PrivateGlobalPrefix; // Defaults to "."
114 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
115 /// be passed through the assembler but be removed by the linker. This
116 /// is "l" on Darwin, currently used for some ObjC metadata.
117 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
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 /// AllowQuotesInName - This is true if the assembler allows for complex
135 /// symbol names to be surrounded in quotes. This defaults to false.
136 bool AllowQuotesInName;
138 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
139 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
140 bool AllowNameToStartWithDigit;
142 /// AllowPeriodsInName - This is true if the assembler allows periods in
143 /// symbol names. This defaults to true.
144 bool AllowPeriodsInName;
146 /// AllowUTF8 - This is true if the assembler accepts UTF-8 input.
147 // FIXME: Make this a more general encoding setting?
150 /// UseDataRegionDirectives - This is true if data region markers should
151 /// be printed as ".data_region/.end_data_region" directives. If false,
152 /// use "$d/$a" labels instead.
153 bool UseDataRegionDirectives;
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 /// GPRel64Directive - if non-null, a directive that is used to emit a word
181 /// which should be relocated as a 64-bit GP-relative offset, e.g. .gpdword
183 const char *GPRel64Directive; // Defaults to NULL.
185 /// GPRel32Directive - if non-null, a directive that is used to emit a word
186 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
187 /// on Mips or .gprel32 on Alpha.
188 const char *GPRel32Directive; // Defaults to NULL.
190 /// getDataASDirective - Return the directive that should be used to emit
191 /// data of the specified size to the specified numeric address space.
192 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const {
193 assert(AS != 0 && "Don't know the directives for default addr space");
197 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
198 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
199 /// normal ELF syntax (,"a,w") in .section directives.
200 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
202 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
203 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
204 /// which doesn't support the '.bss' directive only.
205 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
207 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
208 /// style mangling for functions with X86_StdCall/X86_FastCall calling
210 bool HasMicrosoftFastStdCallMangling; // Defaults to false.
212 //===--- Alignment Information ----------------------------------------===//
214 /// AlignDirective - The directive used to emit round up to an alignment
217 const char *AlignDirective; // Defaults to "\t.align\t"
219 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
220 /// emits ".align N" directives, where N is the number of bytes to align to.
221 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
223 bool AlignmentIsInBytes; // Defaults to true
225 /// TextAlignFillValue - If non-zero, this is used to fill the executable
226 /// space created as the result of a alignment directive.
227 unsigned TextAlignFillValue; // Defaults to 0
229 //===--- Global Variable Emission Directives --------------------------===//
231 /// GlobalDirective - This is the directive used to declare a global entity.
233 const char *GlobalDirective; // Defaults to NULL.
235 /// ExternDirective - This is the directive used to declare external
238 const char *ExternDirective; // Defaults to NULL.
240 /// HasSetDirective - True if the assembler supports the .set directive.
241 bool HasSetDirective; // Defaults to true.
243 /// HasAggressiveSymbolFolding - False if the assembler requires that we use
248 bool HasAggressiveSymbolFolding; // Defaults to true.
250 /// LCOMMDirectiveType - Describes if the target supports the .lcomm
251 /// directive and whether it has an alignment parameter.
252 LCOMM::LCOMMType LCOMMDirectiveType; // Defaults to LCOMM::None.
254 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional
255 /// alignment is to be specified in bytes instead of log2(n).
256 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
258 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
259 /// directives, this is true for most ELF targets.
260 bool HasDotTypeDotSizeDirective; // Defaults to true.
262 /// HasSingleParameterDotFile - True if the target has a single parameter
263 /// .file directive, this is true for ELF targets.
264 bool HasSingleParameterDotFile; // Defaults to true.
266 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
268 bool HasNoDeadStrip; // Defaults to false.
270 /// HasSymbolResolver - True if this target supports the MachO
271 /// .symbol_resolver directive.
272 bool HasSymbolResolver; // Defaults to false.
274 /// WeakRefDirective - This directive, if non-null, is used to declare a
275 /// global as being a weak undefined symbol.
276 const char *WeakRefDirective; // Defaults to NULL.
278 /// WeakDefDirective - This directive, if non-null, is used to declare a
279 /// global as being a weak defined symbol.
280 const char *WeakDefDirective; // Defaults to NULL.
282 /// LinkOnceDirective - This directive, if non-null is used to declare a
283 /// global as being a weak defined symbol. This is used on cygwin/mingw.
284 const char *LinkOnceDirective; // Defaults to NULL.
286 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
287 /// declare a symbol as having hidden visibility.
288 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
290 /// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid,
291 /// is used to declare an undefined symbol as having hidden visibility.
292 MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden.
295 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
296 /// to declare a symbol as having protected visibility.
297 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
299 //===--- Dwarf Emission Directives -----------------------------------===//
301 /// HasLEB128 - True if target asm supports leb128 directives.
302 bool HasLEB128; // Defaults to false.
304 /// SupportsDebugInformation - True if target supports emission of debugging
306 bool SupportsDebugInformation; // Defaults to false.
308 /// SupportsExceptionHandling - True if target supports exception handling.
309 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
311 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to
312 /// encode inline subroutine information.
313 bool DwarfUsesInlineInfoSection; // Defaults to false.
315 /// DwarfSectionOffsetDirective - Special section offset directive.
316 const char* DwarfSectionOffsetDirective; // Defaults to NULL
318 /// DwarfRequiresRelocationForSectionOffset - True if we need to produce a
319 /// relocation when we want a section offset in dwarf.
320 bool DwarfRequiresRelocationForSectionOffset; // Defaults to true;
322 /// DwarfUsesRelocationsAcrossSections - True if Dwarf2 output generally
323 /// uses relocations for references to other .debug_* sections.
324 // FIXME: Can we replace DwarfRequiresRelocationForSectionOffset
326 bool DwarfUsesRelocationsAcrossSections;
328 /// DwarfUsesRelocationsForStringPool - True if this Dwarf output must use
329 /// relocations to refer to entries in the string pool.
330 bool DwarfUsesRelocationsForStringPool;
332 /// DwarfRegNumForCFI - True if dwarf register numbers are printed
333 /// instead of symbolic register names in .cfi_* directives.
334 bool DwarfRegNumForCFI; // Defaults to false;
336 //===--- Prologue State ----------------------------------------------===//
338 std::vector<MachineMove> InitialFrameState;
341 explicit MCAsmInfo();
342 virtual ~MCAsmInfo();
344 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
345 static unsigned getSLEB128Size(int Value);
346 static unsigned getULEB128Size(unsigned Value);
348 /// getPointerSize - Get the pointer size in bytes.
349 unsigned getPointerSize() const {
353 /// islittleendian - True if the target is little endian.
354 bool isLittleEndian() const {
355 return IsLittleEndian;
358 /// isStackGrowthDirectionUp - True if target stack grow up.
359 bool isStackGrowthDirectionUp() const {
363 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
365 // Data directive accessors.
367 const char *getData8bitsDirective(unsigned AS = 0) const {
368 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS);
370 const char *getData16bitsDirective(unsigned AS = 0) const {
371 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS);
373 const char *getData32bitsDirective(unsigned AS = 0) const {
374 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS);
376 const char *getData64bitsDirective(unsigned AS = 0) const {
377 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS);
379 const char *getGPRel64Directive() const { return GPRel64Directive; }
380 const char *getGPRel32Directive() const { return GPRel32Directive; }
382 /// getNonexecutableStackSection - Targets can implement this method to
383 /// specify a section to switch to if the translation unit doesn't have any
384 /// trampolines that require an executable stack.
385 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
389 virtual const MCExpr *
390 getExprForPersonalitySymbol(const MCSymbol *Sym,
392 MCStreamer &Streamer) const;
395 getExprForFDESymbol(const MCSymbol *Sym,
397 MCStreamer &Streamer) const;
399 bool usesSunStyleELFSectionSwitchSyntax() const {
400 return SunStyleELFSectionSwitchSyntax;
403 bool usesELFSectionDirectiveForBSS() const {
404 return UsesELFSectionDirectiveForBSS;
407 bool hasMicrosoftFastStdCallMangling() const {
408 return HasMicrosoftFastStdCallMangling;
413 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
414 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
415 bool hasStaticCtorDtorReferenceInStaticMode() const {
416 return HasStaticCtorDtorReferenceInStaticMode;
418 bool getLinkerRequiresNonEmptyDwarfLines() const {
419 return LinkerRequiresNonEmptyDwarfLines;
421 unsigned getMaxInstLength() const {
422 return MaxInstLength;
424 const char *getPCSymbol() const {
427 const char *getSeparatorString() const {
428 return SeparatorString;
430 unsigned getCommentColumn() const {
431 return CommentColumn;
433 const char *getCommentString() const {
434 return CommentString;
436 const char *getLabelSuffix() const {
439 const char *getGlobalPrefix() const {
442 const char *getPrivateGlobalPrefix() const {
443 return PrivateGlobalPrefix;
445 const char *getLinkerPrivateGlobalPrefix() const {
446 return LinkerPrivateGlobalPrefix;
448 const char *getInlineAsmStart() const {
449 return InlineAsmStart;
451 const char *getInlineAsmEnd() const {
454 const char *getCode16Directive() const {
455 return Code16Directive;
457 const char *getCode32Directive() const {
458 return Code32Directive;
460 const char *getCode64Directive() const {
461 return Code64Directive;
463 unsigned getAssemblerDialect() const {
464 return AssemblerDialect;
466 bool doesAllowQuotesInName() const {
467 return AllowQuotesInName;
469 bool doesAllowNameToStartWithDigit() const {
470 return AllowNameToStartWithDigit;
472 bool doesAllowPeriodsInName() const {
473 return AllowPeriodsInName;
475 bool doesAllowUTF8() const {
478 bool doesSupportDataRegionDirectives() const {
479 return UseDataRegionDirectives;
481 const char *getZeroDirective() const {
482 return ZeroDirective;
484 const char *getAsciiDirective() const {
485 return AsciiDirective;
487 const char *getAscizDirective() const {
488 return AscizDirective;
490 const char *getAlignDirective() const {
491 return AlignDirective;
493 bool getAlignmentIsInBytes() const {
494 return AlignmentIsInBytes;
496 unsigned getTextAlignFillValue() const {
497 return TextAlignFillValue;
499 const char *getGlobalDirective() const {
500 return GlobalDirective;
502 const char *getExternDirective() const {
503 return ExternDirective;
505 bool hasSetDirective() const { return HasSetDirective; }
506 bool hasAggressiveSymbolFolding() const {
507 return HasAggressiveSymbolFolding;
509 LCOMM::LCOMMType getLCOMMDirectiveType() const {
510 return LCOMMDirectiveType;
512 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
513 bool getCOMMDirectiveAlignmentIsInBytes() const {
514 return COMMDirectiveAlignmentIsInBytes;
516 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
517 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
518 bool hasSymbolResolver() const { return HasSymbolResolver; }
519 const char *getWeakRefDirective() const { return WeakRefDirective; }
520 const char *getWeakDefDirective() const { return WeakDefDirective; }
521 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
523 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
524 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const {
525 return HiddenDeclarationVisibilityAttr;
527 MCSymbolAttr getProtectedVisibilityAttr() const {
528 return ProtectedVisibilityAttr;
530 bool hasLEB128() const {
533 bool doesSupportDebugInformation() const {
534 return SupportsDebugInformation;
536 bool doesSupportExceptionHandling() const {
537 return ExceptionsType != ExceptionHandling::None;
539 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
540 return ExceptionsType;
542 bool isExceptionHandlingDwarf() const {
544 (ExceptionsType == ExceptionHandling::DwarfCFI ||
545 ExceptionsType == ExceptionHandling::ARM ||
546 ExceptionsType == ExceptionHandling::Win64);
548 bool doesDwarfUseInlineInfoSection() const {
549 return DwarfUsesInlineInfoSection;
551 const char *getDwarfSectionOffsetDirective() const {
552 return DwarfSectionOffsetDirective;
554 bool doesDwarfRequireRelocationForSectionOffset() const {
555 return DwarfRequiresRelocationForSectionOffset;
557 bool doesDwarfUseRelocationsAcrossSections() const {
558 return DwarfUsesRelocationsAcrossSections;
560 bool doesDwarfUseRelocationsForStringPool() const {
561 return DwarfUsesRelocationsForStringPool;
563 bool useDwarfRegNumForCFI() const {
564 return DwarfRegNumForCFI;
567 void addInitialFrameState(MCSymbol *label, const MachineLocation &D,
568 const MachineLocation &S) {
569 InitialFrameState.push_back(MachineMove(label, D, S));
571 const std::vector<MachineMove> &getInitialFrameState() const {
572 return InitialFrameState;