MCAsmInfo.h revision 6c2cf8b1fbcf70fd9db6fe44032c1ceaa2299760
1//===-- llvm/MC/MCAsmInfo.h - Asm info --------------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 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. 13// 14//===----------------------------------------------------------------------===// 15 16#ifndef LLVM_TARGET_ASM_INFO_H 17#define LLVM_TARGET_ASM_INFO_H 18 19#include "llvm/MC/MachineLocation.h" 20#include "llvm/MC/MCDirectives.h" 21#include <cassert> 22#include <vector> 23 24namespace llvm { 25 class MCExpr; 26 class MCSection; 27 class MCStreamer; 28 class MCSymbol; 29 class MCContext; 30 31 namespace ExceptionHandling { 32 enum ExceptionsType { None, DwarfCFI, SjLj, ARM, Win64 }; 33 } 34 35 namespace LCOMM { 36 enum LCOMMType { None, NoAlignment, ByteAlignment }; 37 } 38 39 /// MCAsmInfo - This class is intended to be used as a base class for asm 40 /// properties and features specific to the target. 41 class MCAsmInfo { 42 protected: 43 //===------------------------------------------------------------------===// 44 // Properties to be set by the target writer, used to configure asm printer. 45 // 46 47 /// PointerSize - Pointer size in bytes. 48 /// Default is 4. 49 unsigned PointerSize; 50 51 /// IsLittleEndian - True if target is little endian. 52 /// Default is true. 53 bool IsLittleEndian; 54 55 /// StackGrowsUp - True if target stack grow up. 56 /// Default is false. 57 bool StackGrowsUp; 58 59 /// HasSubsectionsViaSymbols - True if this target has the MachO 60 /// .subsections_via_symbols directive. 61 bool HasSubsectionsViaSymbols; // Default is false. 62 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. 66 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. 70 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. 76 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. 81 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. 85 86 /// PCSymbol - The symbol used to represent the current PC. Used in PC 87 /// relative expressions. 88 const char *PCSymbol; // Defaults to "$". 89 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 ';' 93 94 /// CommentColumn - This indicates the comment num (zero-based) at 95 /// which asm comments should be printed. 96 unsigned CommentColumn; // Defaults to 40 97 98 /// CommentString - This indicates the comment character used by the 99 /// assembler. 100 const char *CommentString; // Defaults to "#" 101 102 /// LabelSuffix - This is appended to emitted labels. 103 const char *LabelSuffix; // Defaults to ":" 104 105 /// 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 "" 108 109 /// 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 "." 113 114 /// 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 "" 118 119 /// 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" 123 124 /// 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" 130 131 /// AssemblerDialect - Which dialect of an assembler variant to use. 132 unsigned AssemblerDialect; // Defaults to 0 133 134 /// 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; 137 138 /// 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; 141 142 /// AllowPeriodsInName - This is true if the assembler allows periods in 143 /// symbol names. This defaults to true. 144 bool AllowPeriodsInName; 145 146 //===--- Data Emission Directives -------------------------------------===// 147 148 /// ZeroDirective - this should be set to the directive used to get some 149 /// number of zero bytes emitted to the current section. Common cases are 150 /// "\t.zero\t" and "\t.space\t". If this is set to null, the 151 /// Data*bitsDirective's will be used to emit zero bytes. 152 const char *ZeroDirective; // Defaults to "\t.zero\t" 153 154 /// AsciiDirective - This directive allows emission of an ascii string with 155 /// the standard C escape characters embedded into it. 156 const char *AsciiDirective; // Defaults to "\t.ascii\t" 157 158 /// AscizDirective - If not null, this allows for special handling of 159 /// zero terminated strings on this target. This is commonly supported as 160 /// ".asciz". If a target doesn't support this, it can be set to null. 161 const char *AscizDirective; // Defaults to "\t.asciz\t" 162 163 /// DataDirectives - These directives are used to output some unit of 164 /// integer data to the current section. If a data directive is set to 165 /// null, smaller data directives will be used to emit the large sizes. 166 const char *Data8bitsDirective; // Defaults to "\t.byte\t" 167 const char *Data16bitsDirective; // Defaults to "\t.short\t" 168 const char *Data32bitsDirective; // Defaults to "\t.long\t" 169 const char *Data64bitsDirective; // Defaults to "\t.quad\t" 170 171 /// [Data|Code]Begin - These magic labels are used to marked a region as 172 /// data or code, and are used to provide additional information for 173 /// correct disassembly on targets that like to mix data and code within 174 /// a segment. These labels will be implicitly suffixed by the streamer 175 /// to give them unique names. 176 const char *DataBegin; // Defaults to "$d." 177 const char *CodeBegin; // Defaults to "$a." 178 const char *JT8Begin; // Defaults to "$a." 179 const char *JT16Begin; // Defaults to "$a." 180 const char *JT32Begin; // Defaults to "$a." 181 bool SupportsDataRegions; 182 183 /// GPRel64Directive - if non-null, a directive that is used to emit a word 184 /// which should be relocated as a 64-bit GP-relative offset, e.g. .gpdword 185 /// on Mips. 186 const char *GPRel64Directive; // Defaults to NULL. 187 188 /// GPRel32Directive - if non-null, a directive that is used to emit a word 189 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword 190 /// on Mips or .gprel32 on Alpha. 191 const char *GPRel32Directive; // Defaults to NULL. 192 193 /// getDataASDirective - Return the directive that should be used to emit 194 /// data of the specified size to the specified numeric address space. 195 virtual const char *getDataASDirective(unsigned Size, unsigned AS) const { 196 assert(AS != 0 && "Don't know the directives for default addr space"); 197 return 0; 198 } 199 200 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun 201 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the 202 /// normal ELF syntax (,"a,w") in .section directives. 203 bool SunStyleELFSectionSwitchSyntax; // Defaults to false. 204 205 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF 206 /// '.section' directive before the '.bss' one. It's used for PPC/Linux 207 /// which doesn't support the '.bss' directive only. 208 bool UsesELFSectionDirectiveForBSS; // Defaults to false. 209 210 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft 211 /// style mangling for functions with X86_StdCall/X86_FastCall calling 212 /// convention. 213 bool HasMicrosoftFastStdCallMangling; // Defaults to false. 214 215 //===--- Alignment Information ----------------------------------------===// 216 217 /// AlignDirective - The directive used to emit round up to an alignment 218 /// boundary. 219 /// 220 const char *AlignDirective; // Defaults to "\t.align\t" 221 222 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter 223 /// emits ".align N" directives, where N is the number of bytes to align to. 224 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte 225 /// boundary. 226 bool AlignmentIsInBytes; // Defaults to true 227 228 /// TextAlignFillValue - If non-zero, this is used to fill the executable 229 /// space created as the result of a alignment directive. 230 unsigned TextAlignFillValue; // Defaults to 0 231 232 //===--- Global Variable Emission Directives --------------------------===// 233 234 /// GlobalDirective - This is the directive used to declare a global entity. 235 /// 236 const char *GlobalDirective; // Defaults to NULL. 237 238 /// ExternDirective - This is the directive used to declare external 239 /// globals. 240 /// 241 const char *ExternDirective; // Defaults to NULL. 242 243 /// HasSetDirective - True if the assembler supports the .set directive. 244 bool HasSetDirective; // Defaults to true. 245 246 /// HasAggressiveSymbolFolding - False if the assembler requires that we use 247 /// Lc = a - b 248 /// .long Lc 249 /// instead of 250 /// .long a - b 251 bool HasAggressiveSymbolFolding; // Defaults to true. 252 253 /// LCOMMDirectiveType - Describes if the target supports the .lcomm 254 /// directive and whether it has an alignment parameter. 255 LCOMM::LCOMMType LCOMMDirectiveType; // Defaults to LCOMM::None. 256 257 /// COMMDirectiveAlignmentIsInBytes - True is COMMDirective's optional 258 /// alignment is to be specified in bytes instead of log2(n). 259 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true; 260 261 /// HasDotTypeDotSizeDirective - True if the target has .type and .size 262 /// directives, this is true for most ELF targets. 263 bool HasDotTypeDotSizeDirective; // Defaults to true. 264 265 /// HasSingleParameterDotFile - True if the target has a single parameter 266 /// .file directive, this is true for ELF targets. 267 bool HasSingleParameterDotFile; // Defaults to true. 268 269 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip 270 /// directive. 271 bool HasNoDeadStrip; // Defaults to false. 272 273 /// HasSymbolResolver - True if this target supports the MachO 274 /// .symbol_resolver directive. 275 bool HasSymbolResolver; // Defaults to false. 276 277 /// 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. 280 281 /// 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. 284 285 /// 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. 288 289 /// 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. 292 293 /// 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. 296 297 298 /// 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 301 302 //===--- Dwarf Emission Directives -----------------------------------===// 303 304 /// HasLEB128 - True if target asm supports leb128 directives. 305 bool HasLEB128; // Defaults to false. 306 307 /// SupportsDebugInformation - True if target supports emission of debugging 308 /// information. 309 bool SupportsDebugInformation; // Defaults to false. 310 311 /// SupportsExceptionHandling - True if target supports exception handling. 312 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None 313 314 /// DwarfUsesInlineInfoSection - True if DwarfDebugInlineSection is used to 315 /// encode inline subroutine information. 316 bool DwarfUsesInlineInfoSection; // Defaults to false. 317 318 /// DwarfSectionOffsetDirective - Special section offset directive. 319 const char* DwarfSectionOffsetDirective; // Defaults to NULL 320 321 /// DwarfRequiresRelocationForSectionOffset - True if we need to produce a 322 /// relocation when we want a section offset in dwarf. 323 bool DwarfRequiresRelocationForSectionOffset; // Defaults to true; 324 325 /// DwarfUsesLabelOffsetDifference - True if Dwarf2 output can 326 /// use EmitLabelOffsetDifference. 327 bool DwarfUsesLabelOffsetForRanges; 328 329 /// DwarfUsesRelocationsForStringPool - True if this Dwarf output must use 330 /// relocations to refer to entries in the string pool. 331 bool DwarfUsesRelocationsForStringPool; 332 333 /// DwarfRegNumForCFI - True if dwarf register numbers are printed 334 /// instead of symbolic register names in .cfi_* directives. 335 bool DwarfRegNumForCFI; // Defaults to false; 336 337 //===--- CBE Asm Translation Table -----------------------------------===// 338 339 const char *const *AsmTransCBE; // Defaults to empty 340 341 //===--- Prologue State ----------------------------------------------===// 342 343 std::vector<MachineMove> InitialFrameState; 344 345 public: 346 explicit MCAsmInfo(); 347 virtual ~MCAsmInfo(); 348 349 // FIXME: move these methods to DwarfPrinter when the JIT stops using them. 350 static unsigned getSLEB128Size(int Value); 351 static unsigned getULEB128Size(unsigned Value); 352 353 /// getPointerSize - Get the pointer size in bytes. 354 unsigned getPointerSize() const { 355 return PointerSize; 356 } 357 358 /// islittleendian - True if the target is little endian. 359 bool isLittleEndian() const { 360 return IsLittleEndian; 361 } 362 363 /// isStackGrowthDirectionUp - True if target stack grow up. 364 bool isStackGrowthDirectionUp() const { 365 return StackGrowsUp; 366 } 367 368 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; } 369 370 // Data directive accessors. 371 // 372 const char *getData8bitsDirective(unsigned AS = 0) const { 373 return AS == 0 ? Data8bitsDirective : getDataASDirective(8, AS); 374 } 375 const char *getData16bitsDirective(unsigned AS = 0) const { 376 return AS == 0 ? Data16bitsDirective : getDataASDirective(16, AS); 377 } 378 const char *getData32bitsDirective(unsigned AS = 0) const { 379 return AS == 0 ? Data32bitsDirective : getDataASDirective(32, AS); 380 } 381 const char *getData64bitsDirective(unsigned AS = 0) const { 382 return AS == 0 ? Data64bitsDirective : getDataASDirective(64, AS); 383 } 384 const char *getGPRel64Directive() const { return GPRel64Directive; } 385 const char *getGPRel32Directive() const { return GPRel32Directive; } 386 387 /// [Code|Data]Begin label name accessors. 388 const char *getCodeBeginLabelName() const { return CodeBegin; } 389 const char *getDataBeginLabelName() const { return DataBegin; } 390 const char *getJumpTable8BeginLabelName() const { return JT8Begin; } 391 const char *getJumpTable16BeginLabelName() const { return JT16Begin; } 392 const char *getJumpTable32BeginLabelName() const { return JT32Begin; } 393 bool getSupportsDataRegions() const { return SupportsDataRegions; } 394 395 /// getNonexecutableStackSection - Targets can implement this method to 396 /// specify a section to switch to if the translation unit doesn't have any 397 /// trampolines that require an executable stack. 398 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{ 399 return 0; 400 } 401 402 virtual const MCExpr * 403 getExprForPersonalitySymbol(const MCSymbol *Sym, 404 unsigned Encoding, 405 MCStreamer &Streamer) const; 406 407 const MCExpr * 408 getExprForFDESymbol(const MCSymbol *Sym, 409 unsigned Encoding, 410 MCStreamer &Streamer) const; 411 412 bool usesSunStyleELFSectionSwitchSyntax() const { 413 return SunStyleELFSectionSwitchSyntax; 414 } 415 416 bool usesELFSectionDirectiveForBSS() const { 417 return UsesELFSectionDirectiveForBSS; 418 } 419 420 bool hasMicrosoftFastStdCallMangling() const { 421 return HasMicrosoftFastStdCallMangling; 422 } 423 424 // Accessors. 425 // 426 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; } 427 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; } 428 bool hasStaticCtorDtorReferenceInStaticMode() const { 429 return HasStaticCtorDtorReferenceInStaticMode; 430 } 431 bool getLinkerRequiresNonEmptyDwarfLines() const { 432 return LinkerRequiresNonEmptyDwarfLines; 433 } 434 unsigned getMaxInstLength() const { 435 return MaxInstLength; 436 } 437 const char *getPCSymbol() const { 438 return PCSymbol; 439 } 440 const char *getSeparatorString() const { 441 return SeparatorString; 442 } 443 unsigned getCommentColumn() const { 444 return CommentColumn; 445 } 446 const char *getCommentString() const { 447 return CommentString; 448 } 449 const char *getLabelSuffix() const { 450 return LabelSuffix; 451 } 452 const char *getGlobalPrefix() const { 453 return GlobalPrefix; 454 } 455 const char *getPrivateGlobalPrefix() const { 456 return PrivateGlobalPrefix; 457 } 458 const char *getLinkerPrivateGlobalPrefix() const { 459 return LinkerPrivateGlobalPrefix; 460 } 461 const char *getInlineAsmStart() const { 462 return InlineAsmStart; 463 } 464 const char *getInlineAsmEnd() const { 465 return InlineAsmEnd; 466 } 467 const char *getCode16Directive() const { 468 return Code16Directive; 469 } 470 const char *getCode32Directive() const { 471 return Code32Directive; 472 } 473 const char *getCode64Directive() const { 474 return Code64Directive; 475 } 476 unsigned getAssemblerDialect() const { 477 return AssemblerDialect; 478 } 479 bool doesAllowQuotesInName() const { 480 return AllowQuotesInName; 481 } 482 bool doesAllowNameToStartWithDigit() const { 483 return AllowNameToStartWithDigit; 484 } 485 bool doesAllowPeriodsInName() const { 486 return AllowPeriodsInName; 487 } 488 const char *getZeroDirective() const { 489 return ZeroDirective; 490 } 491 const char *getAsciiDirective() const { 492 return AsciiDirective; 493 } 494 const char *getAscizDirective() const { 495 return AscizDirective; 496 } 497 const char *getAlignDirective() const { 498 return AlignDirective; 499 } 500 bool getAlignmentIsInBytes() const { 501 return AlignmentIsInBytes; 502 } 503 unsigned getTextAlignFillValue() const { 504 return TextAlignFillValue; 505 } 506 const char *getGlobalDirective() const { 507 return GlobalDirective; 508 } 509 const char *getExternDirective() const { 510 return ExternDirective; 511 } 512 bool hasSetDirective() const { return HasSetDirective; } 513 bool hasAggressiveSymbolFolding() const { 514 return HasAggressiveSymbolFolding; 515 } 516 LCOMM::LCOMMType getLCOMMDirectiveType() const { 517 return LCOMMDirectiveType; 518 } 519 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;} 520 bool getCOMMDirectiveAlignmentIsInBytes() const { 521 return COMMDirectiveAlignmentIsInBytes; 522 } 523 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; } 524 bool hasNoDeadStrip() const { return HasNoDeadStrip; } 525 bool hasSymbolResolver() const { return HasSymbolResolver; } 526 const char *getWeakRefDirective() const { return WeakRefDirective; } 527 const char *getWeakDefDirective() const { return WeakDefDirective; } 528 const char *getLinkOnceDirective() const { return LinkOnceDirective; } 529 530 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;} 531 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const { 532 return HiddenDeclarationVisibilityAttr; 533 } 534 MCSymbolAttr getProtectedVisibilityAttr() const { 535 return ProtectedVisibilityAttr; 536 } 537 bool hasLEB128() const { 538 return HasLEB128; 539 } 540 bool doesSupportDebugInformation() const { 541 return SupportsDebugInformation; 542 } 543 bool doesSupportExceptionHandling() const { 544 return ExceptionsType != ExceptionHandling::None; 545 } 546 ExceptionHandling::ExceptionsType getExceptionHandlingType() const { 547 return ExceptionsType; 548 } 549 bool isExceptionHandlingDwarf() const { 550 return 551 (ExceptionsType == ExceptionHandling::DwarfCFI || 552 ExceptionsType == ExceptionHandling::ARM || 553 ExceptionsType == ExceptionHandling::Win64); 554 } 555 bool doesDwarfUsesInlineInfoSection() const { 556 return DwarfUsesInlineInfoSection; 557 } 558 const char *getDwarfSectionOffsetDirective() const { 559 return DwarfSectionOffsetDirective; 560 } 561 bool doesDwarfRequireRelocationForSectionOffset() const { 562 return DwarfRequiresRelocationForSectionOffset; 563 } 564 bool doesDwarfUsesLabelOffsetForRanges() const { 565 return DwarfUsesLabelOffsetForRanges; 566 } 567 bool doesDwarfUseRelocationsForStringPool() const { 568 return DwarfUsesRelocationsForStringPool; 569 } 570 bool useDwarfRegNumForCFI() const { 571 return DwarfRegNumForCFI; 572 } 573 const char *const *getAsmCBE() const { 574 return AsmTransCBE; 575 } 576 577 void addInitialFrameState(MCSymbol *label, const MachineLocation &D, 578 const MachineLocation &S) { 579 InitialFrameState.push_back(MachineMove(label, D, S)); 580 } 581 const std::vector<MachineMove> &getInitialFrameState() const { 582 return InitialFrameState; 583 } 584 }; 585} 586 587#endif 588