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 /// CommentColumn - This indicates the comment num (zero-based) at
105 /// which asm comments should be printed.
106 unsigned CommentColumn; // Defaults to 40
108 /// CommentString - This indicates the comment character used by the
110 const char *CommentString; // Defaults to "#"
112 /// LabelSuffix - This is appended to emitted labels.
113 const char *LabelSuffix; // Defaults to ":"
115 /// LabelSuffix - This is appended to emitted labels.
116 const char *DebugLabelSuffix; // Defaults to ":"
118 /// GlobalPrefix - If this is set to a non-empty string, it is prepended
119 /// onto all global symbols. This is often used for "_" or ".".
120 const char *GlobalPrefix; // Defaults to ""
122 /// PrivateGlobalPrefix - This prefix is used for globals like constant
123 /// pool entries that are completely private to the .s file and should not
124 /// have names in the .o file. This is often "." or "L".
125 const char *PrivateGlobalPrefix; // Defaults to "."
127 /// LinkerPrivateGlobalPrefix - This prefix is used for symbols that should
128 /// be passed through the assembler but be removed by the linker. This
129 /// is "l" on Darwin, currently used for some ObjC metadata.
130 const char *LinkerPrivateGlobalPrefix; // Defaults to ""
132 /// InlineAsmStart/End - If these are nonempty, they contain a directive to
133 /// emit before and after an inline assembly statement.
134 const char *InlineAsmStart; // Defaults to "#APP\n"
135 const char *InlineAsmEnd; // Defaults to "#NO_APP\n"
137 /// Code16Directive, Code32Directive, Code64Directive - These are assembly
138 /// directives that tells the assembler to interpret the following
139 /// instructions differently.
140 const char *Code16Directive; // Defaults to ".code16"
141 const char *Code32Directive; // Defaults to ".code32"
142 const char *Code64Directive; // Defaults to ".code64"
144 /// AssemblerDialect - Which dialect of an assembler variant to use.
145 unsigned AssemblerDialect; // Defaults to 0
147 /// AllowQuotesInName - This is true if the assembler allows for complex
148 /// symbol names to be surrounded in quotes. This defaults to false.
149 bool AllowQuotesInName;
151 /// AllowNameToStartWithDigit - This is true if the assembler allows symbol
152 /// names to start with a digit (e.g., "0x0021"). This defaults to false.
153 bool AllowNameToStartWithDigit;
155 /// AllowPeriodsInName - This is true if the assembler allows periods in
156 /// symbol names. This defaults to true.
157 bool AllowPeriodsInName;
159 /// \brief This is true if the assembler allows @ characters in symbol
160 /// names. Defaults to false.
163 /// UseDataRegionDirectives - This is true if data region markers should
164 /// be printed as ".data_region/.end_data_region" directives. If false,
165 /// use "$d/$a" labels instead.
166 bool UseDataRegionDirectives;
168 //===--- Data Emission Directives -------------------------------------===//
170 /// ZeroDirective - this should be set to the directive used to get some
171 /// number of zero bytes emitted to the current section. Common cases are
172 /// "\t.zero\t" and "\t.space\t". If this is set to null, the
173 /// Data*bitsDirective's will be used to emit zero bytes.
174 const char *ZeroDirective; // Defaults to "\t.zero\t"
176 /// AsciiDirective - This directive allows emission of an ascii string with
177 /// the standard C escape characters embedded into it.
178 const char *AsciiDirective; // Defaults to "\t.ascii\t"
180 /// AscizDirective - If not null, this allows for special handling of
181 /// zero terminated strings on this target. This is commonly supported as
182 /// ".asciz". If a target doesn't support this, it can be set to null.
183 const char *AscizDirective; // Defaults to "\t.asciz\t"
185 /// DataDirectives - These directives are used to output some unit of
186 /// integer data to the current section. If a data directive is set to
187 /// null, smaller data directives will be used to emit the large sizes.
188 const char *Data8bitsDirective; // Defaults to "\t.byte\t"
189 const char *Data16bitsDirective; // Defaults to "\t.short\t"
190 const char *Data32bitsDirective; // Defaults to "\t.long\t"
191 const char *Data64bitsDirective; // Defaults to "\t.quad\t"
193 /// GPRel64Directive - if non-null, a directive that is used to emit a word
194 /// which should be relocated as a 64-bit GP-relative offset, e.g. .gpdword
196 const char *GPRel64Directive; // Defaults to NULL.
198 /// GPRel32Directive - if non-null, a directive that is used to emit a word
199 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword
200 /// on Mips or .gprel32 on Alpha.
201 const char *GPRel32Directive; // Defaults to NULL.
203 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun
204 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the
205 /// normal ELF syntax (,"a,w") in .section directives.
206 bool SunStyleELFSectionSwitchSyntax; // Defaults to false.
208 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF
209 /// '.section' directive before the '.bss' one. It's used for PPC/Linux
210 /// which doesn't support the '.bss' directive only.
211 bool UsesELFSectionDirectiveForBSS; // Defaults to false.
213 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft
214 /// style mangling for functions with X86_StdCall/X86_FastCall calling
216 bool HasMicrosoftFastStdCallMangling; // Defaults to false.
218 bool NeedsDwarfSectionOffsetDirective;
220 //===--- Alignment Information ----------------------------------------===//
222 /// AlignDirective - The directive used to emit round up to an alignment
225 const char *AlignDirective; // Defaults to "\t.align\t"
227 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter
228 /// emits ".align N" directives, where N is the number of bytes to align to.
229 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte
231 bool AlignmentIsInBytes; // Defaults to true
233 /// TextAlignFillValue - If non-zero, this is used to fill the executable
234 /// space created as the result of a alignment directive.
235 unsigned TextAlignFillValue; // Defaults to 0
237 //===--- Global Variable Emission Directives --------------------------===//
239 /// GlobalDirective - This is the directive used to declare a global entity.
241 const char *GlobalDirective; // Defaults to NULL.
243 /// HasSetDirective - True if the assembler supports the .set directive.
244 bool HasSetDirective; // Defaults to true.
246 /// HasAggressiveSymbolFolding - False if the assembler requires that we use
251 bool HasAggressiveSymbolFolding; // Defaults to true.
253 /// COMMDirectiveAlignmentIsInBytes - True is .comm's and .lcomms optional
254 /// alignment is to be specified in bytes instead of log2(n).
255 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true;
257 /// LCOMMDirectiveAlignment - Describes if the .lcomm directive for the
258 /// target supports an alignment argument and how it is interpreted.
259 LCOMM::LCOMMType LCOMMDirectiveAlignmentType; // Defaults to NoAlignment.
261 /// HasDotTypeDotSizeDirective - True if the target has .type and .size
262 /// directives, this is true for most ELF targets.
263 bool HasDotTypeDotSizeDirective; // Defaults to true.
265 /// HasSingleParameterDotFile - True if the target has a single parameter
266 /// .file directive, this is true for ELF targets.
267 bool HasSingleParameterDotFile; // Defaults to true.
269 /// hasIdentDirective - True if the target has a .ident directive, this is
270 /// true for ELF targets.
271 bool HasIdentDirective; // Defaults to false.
273 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip
275 bool HasNoDeadStrip; // Defaults to false.
277 /// WeakRefDirective - This directive, if non-null, is used to declare a
278 /// global as being a weak undefined symbol.
279 const char *WeakRefDirective; // Defaults to NULL.
281 /// WeakDefDirective - This directive, if non-null, is used to declare a
282 /// global as being a weak defined symbol.
283 const char *WeakDefDirective; // Defaults to NULL.
285 /// LinkOnceDirective - This directive, if non-null is used to declare a
286 /// global as being a weak defined symbol. This is used on cygwin/mingw.
287 const char *LinkOnceDirective; // Defaults to NULL.
289 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to
290 /// declare a symbol as having hidden visibility.
291 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden.
293 /// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid,
294 /// is used to declare an undefined symbol as having hidden visibility.
295 MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden.
298 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used
299 /// to declare a symbol as having protected visibility.
300 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected
302 //===--- Dwarf Emission Directives -----------------------------------===//
304 /// HasLEB128 - True if target asm supports leb128 directives.
305 bool HasLEB128; // Defaults to false.
307 /// SupportsDebugInformation - True if target supports emission of debugging
309 bool SupportsDebugInformation; // Defaults to false.
311 /// SupportsExceptionHandling - True if target supports exception handling.
312 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None
314 /// DwarfUsesRelocationsAcrossSections - True if Dwarf2 output generally
315 /// uses relocations for references to other .debug_* sections.
316 bool DwarfUsesRelocationsAcrossSections;
318 /// DwarfRegNumForCFI - True if dwarf register numbers are printed
319 /// instead of symbolic register names in .cfi_* directives.
320 bool DwarfRegNumForCFI; // Defaults to false;
322 //===--- Prologue State ----------------------------------------------===//
324 std::vector<MCCFIInstruction> InitialFrameState;
327 explicit MCAsmInfo();
328 virtual ~MCAsmInfo();
330 // FIXME: move these methods to DwarfPrinter when the JIT stops using them.
331 static unsigned getSLEB128Size(int64_t Value);
332 static unsigned getULEB128Size(uint64_t Value);
334 /// getPointerSize - Get the pointer size in bytes.
335 unsigned getPointerSize() const {
339 /// getCalleeSaveStackSlotSize - Get the callee-saved register stack slot
341 unsigned getCalleeSaveStackSlotSize() const {
342 return CalleeSaveStackSlotSize;
345 /// isLittleEndian - True if the target is little endian.
346 bool isLittleEndian() const {
347 return IsLittleEndian;
350 /// isStackGrowthDirectionUp - True if target stack grow up.
351 bool isStackGrowthDirectionUp() const {
355 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; }
357 // Data directive accessors.
359 const char *getData8bitsDirective() const {
360 return Data8bitsDirective;
362 const char *getData16bitsDirective() const {
363 return Data16bitsDirective;
365 const char *getData32bitsDirective() const {
366 return Data32bitsDirective;
368 const char *getData64bitsDirective() const {
369 return Data64bitsDirective;
371 const char *getGPRel64Directive() const { return GPRel64Directive; }
372 const char *getGPRel32Directive() const { return GPRel32Directive; }
374 /// getNonexecutableStackSection - Targets can implement this method to
375 /// specify a section to switch to if the translation unit doesn't have any
376 /// trampolines that require an executable stack.
377 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{
381 virtual const MCExpr *
382 getExprForPersonalitySymbol(const MCSymbol *Sym,
384 MCStreamer &Streamer) const;
387 getExprForFDESymbol(const MCSymbol *Sym,
389 MCStreamer &Streamer) const;
391 bool usesSunStyleELFSectionSwitchSyntax() const {
392 return SunStyleELFSectionSwitchSyntax;
395 bool usesELFSectionDirectiveForBSS() const {
396 return UsesELFSectionDirectiveForBSS;
399 bool hasMicrosoftFastStdCallMangling() const {
400 return HasMicrosoftFastStdCallMangling;
403 bool needsDwarfSectionOffsetDirective() const {
404 return NeedsDwarfSectionOffsetDirective;
409 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; }
410 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; }
411 bool hasStaticCtorDtorReferenceInStaticMode() const {
412 return HasStaticCtorDtorReferenceInStaticMode;
414 bool getLinkerRequiresNonEmptyDwarfLines() const {
415 return LinkerRequiresNonEmptyDwarfLines;
417 unsigned getMaxInstLength() const {
418 return MaxInstLength;
420 unsigned getMinInstAlignment() const {
421 return MinInstAlignment;
423 bool getDollarIsPC() const {
426 const char *getSeparatorString() const {
427 return SeparatorString;
429 unsigned getCommentColumn() const {
430 return CommentColumn;
432 const char *getCommentString() const {
433 return CommentString;
435 const char *getLabelSuffix() const {
439 const char *getDebugLabelSuffix() const {
440 return DebugLabelSuffix;
443 const char *getGlobalPrefix() const {
446 const char *getPrivateGlobalPrefix() const {
447 return PrivateGlobalPrefix;
449 const char *getLinkerPrivateGlobalPrefix() const {
450 return LinkerPrivateGlobalPrefix;
452 const char *getInlineAsmStart() const {
453 return InlineAsmStart;
455 const char *getInlineAsmEnd() const {
458 const char *getCode16Directive() const {
459 return Code16Directive;
461 const char *getCode32Directive() const {
462 return Code32Directive;
464 const char *getCode64Directive() const {
465 return Code64Directive;
467 unsigned getAssemblerDialect() const {
468 return AssemblerDialect;
470 bool doesAllowQuotesInName() const {
471 return AllowQuotesInName;
473 bool doesAllowNameToStartWithDigit() const {
474 return AllowNameToStartWithDigit;
476 bool doesAllowPeriodsInName() const {
477 return AllowPeriodsInName;
479 bool doesAllowAtInName() const {
480 return AllowAtInName;
482 bool doesSupportDataRegionDirectives() const {
483 return UseDataRegionDirectives;
485 const char *getZeroDirective() const {
486 return ZeroDirective;
488 const char *getAsciiDirective() const {
489 return AsciiDirective;
491 const char *getAscizDirective() const {
492 return AscizDirective;
494 const char *getAlignDirective() const {
495 return AlignDirective;
497 bool getAlignmentIsInBytes() const {
498 return AlignmentIsInBytes;
500 unsigned getTextAlignFillValue() const {
501 return TextAlignFillValue;
503 const char *getGlobalDirective() const {
504 return GlobalDirective;
506 bool hasSetDirective() const { return HasSetDirective; }
507 bool hasAggressiveSymbolFolding() const {
508 return HasAggressiveSymbolFolding;
510 bool getCOMMDirectiveAlignmentIsInBytes() const {
511 return COMMDirectiveAlignmentIsInBytes;
513 LCOMM::LCOMMType getLCOMMDirectiveAlignmentType() const {
514 return LCOMMDirectiveAlignmentType;
516 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;}
517 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }
518 bool hasIdentDirective() const { return HasIdentDirective; }
519 bool hasNoDeadStrip() const { return HasNoDeadStrip; }
520 const char *getWeakRefDirective() const { return WeakRefDirective; }
521 const char *getWeakDefDirective() const { return WeakDefDirective; }
522 const char *getLinkOnceDirective() const { return LinkOnceDirective; }
524 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;}
525 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const {
526 return HiddenDeclarationVisibilityAttr;
528 MCSymbolAttr getProtectedVisibilityAttr() const {
529 return ProtectedVisibilityAttr;
531 bool hasLEB128() const {
534 bool doesSupportDebugInformation() const {
535 return SupportsDebugInformation;
537 bool doesSupportExceptionHandling() const {
538 return ExceptionsType != ExceptionHandling::None;
540 ExceptionHandling::ExceptionsType getExceptionHandlingType() const {
541 return ExceptionsType;
543 bool isExceptionHandlingDwarf() const {
545 (ExceptionsType == ExceptionHandling::DwarfCFI ||
546 ExceptionsType == ExceptionHandling::ARM ||
547 ExceptionsType == ExceptionHandling::Win64);
549 bool doesDwarfUseRelocationsAcrossSections() const {
550 return DwarfUsesRelocationsAcrossSections;
552 bool useDwarfRegNumForCFI() const {
553 return DwarfRegNumForCFI;
556 void addInitialFrameState(const MCCFIInstruction &Inst) {
557 InitialFrameState.push_back(Inst);
560 const std::vector<MCCFIInstruction> &getInitialFrameState() const {
561 return InitialFrameState;