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_MC_MCASMINFO_H 17#define LLVM_MC_MCASMINFO_H 18 19#include "llvm/MC/MCDirectives.h" 20#include "llvm/MC/MCDwarf.h" 21#include "llvm/MC/MachineLocation.h" 22#include <cassert> 23#include <vector> 24 25namespace llvm { 26 class MCExpr; 27 class MCSection; 28 class MCStreamer; 29 class MCSymbol; 30 class MCContext; 31 32 namespace ExceptionHandling { 33 enum ExceptionsType { None, DwarfCFI, SjLj, ARM, Win64 }; 34 } 35 36 namespace LCOMM { 37 enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment }; 38 } 39 40 /// MCAsmInfo - This class is intended to be used as a base class for asm 41 /// properties and features specific to the target. 42 class MCAsmInfo { 43 protected: 44 //===------------------------------------------------------------------===// 45 // Properties to be set by the target writer, used to configure asm printer. 46 // 47 48 /// PointerSize - Pointer size in bytes. 49 /// Default is 4. 50 unsigned PointerSize; 51 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; 56 57 /// IsLittleEndian - True if target is little endian. 58 /// Default is true. 59 bool IsLittleEndian; 60 61 /// StackGrowsUp - True if target stack grow up. 62 /// Default is false. 63 bool StackGrowsUp; 64 65 /// HasSubsectionsViaSymbols - True if this target has the MachO 66 /// .subsections_via_symbols directive. 67 bool HasSubsectionsViaSymbols; // Default is false. 68 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. 72 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. 76 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. 82 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. 87 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. 91 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. 95 96 /// DollarIsPC - The '$' token, when not referencing an identifier or 97 /// constant, refers to the current PC. 98 bool DollarIsPC; // Defaults to false. 99 100 /// 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 ';' 103 104 /// CommentColumn - This indicates the comment num (zero-based) at 105 /// which asm comments should be printed. 106 unsigned CommentColumn; // Defaults to 40 107 108 /// CommentString - This indicates the comment character used by the 109 /// assembler. 110 const char *CommentString; // Defaults to "#" 111 112 /// LabelSuffix - This is appended to emitted labels. 113 const char *LabelSuffix; // Defaults to ":" 114 115 /// LabelSuffix - This is appended to emitted labels. 116 const char *DebugLabelSuffix; // Defaults to ":" 117 118 /// 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 "" 121 122 /// 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 "." 126 127 /// 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 "" 131 132 /// 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" 136 137 /// 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" 143 144 /// AssemblerDialect - Which dialect of an assembler variant to use. 145 unsigned AssemblerDialect; // Defaults to 0 146 147 /// \brief This is true if the assembler allows @ characters in symbol 148 /// names. Defaults to false. 149 bool AllowAtInName; 150 151 /// UseDataRegionDirectives - This is true if data region markers should 152 /// be printed as ".data_region/.end_data_region" directives. If false, 153 /// use "$d/$a" labels instead. 154 bool UseDataRegionDirectives; 155 156 //===--- Data Emission Directives -------------------------------------===// 157 158 /// ZeroDirective - this should be set to the directive used to get some 159 /// number of zero bytes emitted to the current section. Common cases are 160 /// "\t.zero\t" and "\t.space\t". If this is set to null, the 161 /// Data*bitsDirective's will be used to emit zero bytes. 162 const char *ZeroDirective; // Defaults to "\t.zero\t" 163 164 /// AsciiDirective - This directive allows emission of an ascii string with 165 /// the standard C escape characters embedded into it. 166 const char *AsciiDirective; // Defaults to "\t.ascii\t" 167 168 /// AscizDirective - If not null, this allows for special handling of 169 /// zero terminated strings on this target. This is commonly supported as 170 /// ".asciz". If a target doesn't support this, it can be set to null. 171 const char *AscizDirective; // Defaults to "\t.asciz\t" 172 173 /// DataDirectives - These directives are used to output some unit of 174 /// integer data to the current section. If a data directive is set to 175 /// null, smaller data directives will be used to emit the large sizes. 176 const char *Data8bitsDirective; // Defaults to "\t.byte\t" 177 const char *Data16bitsDirective; // Defaults to "\t.short\t" 178 const char *Data32bitsDirective; // Defaults to "\t.long\t" 179 const char *Data64bitsDirective; // Defaults to "\t.quad\t" 180 181 /// GPRel64Directive - if non-null, a directive that is used to emit a word 182 /// which should be relocated as a 64-bit GP-relative offset, e.g. .gpdword 183 /// on Mips. 184 const char *GPRel64Directive; // Defaults to NULL. 185 186 /// GPRel32Directive - if non-null, a directive that is used to emit a word 187 /// which should be relocated as a 32-bit GP-relative offset, e.g. .gpword 188 /// on Mips or .gprel32 on Alpha. 189 const char *GPRel32Directive; // Defaults to NULL. 190 191 /// SunStyleELFSectionSwitchSyntax - This is true if this target uses "Sun 192 /// Style" syntax for section switching ("#alloc,#write" etc) instead of the 193 /// normal ELF syntax (,"a,w") in .section directives. 194 bool SunStyleELFSectionSwitchSyntax; // Defaults to false. 195 196 /// UsesELFSectionDirectiveForBSS - This is true if this target uses ELF 197 /// '.section' directive before the '.bss' one. It's used for PPC/Linux 198 /// which doesn't support the '.bss' directive only. 199 bool UsesELFSectionDirectiveForBSS; // Defaults to false. 200 201 /// HasMicrosoftFastStdCallMangling - True if this target uses microsoft 202 /// style mangling for functions with X86_StdCall/X86_FastCall calling 203 /// convention. 204 bool HasMicrosoftFastStdCallMangling; // Defaults to false. 205 206 bool NeedsDwarfSectionOffsetDirective; 207 208 //===--- Alignment Information ----------------------------------------===// 209 210 /// AlignDirective - The directive used to emit round up to an alignment 211 /// boundary. 212 /// 213 const char *AlignDirective; // Defaults to "\t.align\t" 214 215 /// AlignmentIsInBytes - If this is true (the default) then the asmprinter 216 /// emits ".align N" directives, where N is the number of bytes to align to. 217 /// Otherwise, it emits ".align log2(N)", e.g. 3 to align to an 8 byte 218 /// boundary. 219 bool AlignmentIsInBytes; // Defaults to true 220 221 /// TextAlignFillValue - If non-zero, this is used to fill the executable 222 /// space created as the result of a alignment directive. 223 unsigned TextAlignFillValue; // Defaults to 0 224 225 //===--- Global Variable Emission Directives --------------------------===// 226 227 /// GlobalDirective - This is the directive used to declare a global entity. 228 /// 229 const char *GlobalDirective; // Defaults to NULL. 230 231 /// HasSetDirective - True if the assembler supports the .set directive. 232 bool HasSetDirective; // Defaults to true. 233 234 /// HasAggressiveSymbolFolding - False if the assembler requires that we use 235 /// Lc = a - b 236 /// .long Lc 237 /// instead of 238 /// .long a - b 239 bool HasAggressiveSymbolFolding; // Defaults to true. 240 241 /// COMMDirectiveAlignmentIsInBytes - True is .comm's and .lcomms optional 242 /// alignment is to be specified in bytes instead of log2(n). 243 bool COMMDirectiveAlignmentIsInBytes; // Defaults to true; 244 245 /// LCOMMDirectiveAlignment - Describes if the .lcomm directive for the 246 /// target supports an alignment argument and how it is interpreted. 247 LCOMM::LCOMMType LCOMMDirectiveAlignmentType; // Defaults to NoAlignment. 248 249 /// HasDotTypeDotSizeDirective - True if the target has .type and .size 250 /// directives, this is true for most ELF targets. 251 bool HasDotTypeDotSizeDirective; // Defaults to true. 252 253 /// HasSingleParameterDotFile - True if the target has a single parameter 254 /// .file directive, this is true for ELF targets. 255 bool HasSingleParameterDotFile; // Defaults to true. 256 257 /// hasIdentDirective - True if the target has a .ident directive, this is 258 /// true for ELF targets. 259 bool HasIdentDirective; // Defaults to false. 260 261 /// HasNoDeadStrip - True if this target supports the MachO .no_dead_strip 262 /// directive. 263 bool HasNoDeadStrip; // Defaults to false. 264 265 /// WeakRefDirective - This directive, if non-null, is used to declare a 266 /// global as being a weak undefined symbol. 267 const char *WeakRefDirective; // Defaults to NULL. 268 269 /// True if we have a directive to declare a global as being a weak 270 /// defined symbol. 271 bool HasWeakDefDirective; // Defaults to false. 272 273 /// True if we have a directive to declare a global as being a weak 274 /// defined symbol that can be hidden (unexported). 275 bool HasWeakDefCanBeHiddenDirective; // Defaults to false. 276 277 /// True if we have a .linkonce directive. This is used on cygwin/mingw. 278 bool HasLinkOnceDirective; // Defaults to false. 279 280 /// HiddenVisibilityAttr - This attribute, if not MCSA_Invalid, is used to 281 /// declare a symbol as having hidden visibility. 282 MCSymbolAttr HiddenVisibilityAttr; // Defaults to MCSA_Hidden. 283 284 /// HiddenDeclarationVisibilityAttr - This attribute, if not MCSA_Invalid, 285 /// is used to declare an undefined symbol as having hidden visibility. 286 MCSymbolAttr HiddenDeclarationVisibilityAttr; // Defaults to MCSA_Hidden. 287 288 289 /// ProtectedVisibilityAttr - This attribute, if not MCSA_Invalid, is used 290 /// to declare a symbol as having protected visibility. 291 MCSymbolAttr ProtectedVisibilityAttr; // Defaults to MCSA_Protected 292 293 //===--- Dwarf Emission Directives -----------------------------------===// 294 295 /// HasLEB128 - True if target asm supports leb128 directives. 296 bool HasLEB128; // Defaults to false. 297 298 /// SupportsDebugInformation - True if target supports emission of debugging 299 /// information. 300 bool SupportsDebugInformation; // Defaults to false. 301 302 /// SupportsExceptionHandling - True if target supports exception handling. 303 ExceptionHandling::ExceptionsType ExceptionsType; // Defaults to None 304 305 /// DwarfUsesRelocationsAcrossSections - True if Dwarf2 output generally 306 /// uses relocations for references to other .debug_* sections. 307 bool DwarfUsesRelocationsAcrossSections; 308 309 /// DwarfFDESymbolsUseAbsDiff - true if DWARF FDE symbol reference 310 /// relocations should be replaced by an absolute difference. 311 bool DwarfFDESymbolsUseAbsDiff; 312 313 /// DwarfRegNumForCFI - True if dwarf register numbers are printed 314 /// instead of symbolic register names in .cfi_* directives. 315 bool DwarfRegNumForCFI; // Defaults to false; 316 317 //===--- Prologue State ----------------------------------------------===// 318 319 std::vector<MCCFIInstruction> InitialFrameState; 320 321 public: 322 explicit MCAsmInfo(); 323 virtual ~MCAsmInfo(); 324 325 // FIXME: move these methods to DwarfPrinter when the JIT stops using them. 326 static unsigned getSLEB128Size(int64_t Value); 327 static unsigned getULEB128Size(uint64_t Value); 328 329 /// getPointerSize - Get the pointer size in bytes. 330 unsigned getPointerSize() const { 331 return PointerSize; 332 } 333 334 /// getCalleeSaveStackSlotSize - Get the callee-saved register stack slot 335 /// size in bytes. 336 unsigned getCalleeSaveStackSlotSize() const { 337 return CalleeSaveStackSlotSize; 338 } 339 340 /// isLittleEndian - True if the target is little endian. 341 bool isLittleEndian() const { 342 return IsLittleEndian; 343 } 344 345 /// isStackGrowthDirectionUp - True if target stack grow up. 346 bool isStackGrowthDirectionUp() const { 347 return StackGrowsUp; 348 } 349 350 bool hasSubsectionsViaSymbols() const { return HasSubsectionsViaSymbols; } 351 352 // Data directive accessors. 353 // 354 const char *getData8bitsDirective() const { 355 return Data8bitsDirective; 356 } 357 const char *getData16bitsDirective() const { 358 return Data16bitsDirective; 359 } 360 const char *getData32bitsDirective() const { 361 return Data32bitsDirective; 362 } 363 const char *getData64bitsDirective() const { 364 return Data64bitsDirective; 365 } 366 const char *getGPRel64Directive() const { return GPRel64Directive; } 367 const char *getGPRel32Directive() const { return GPRel32Directive; } 368 369 /// getNonexecutableStackSection - Targets can implement this method to 370 /// specify a section to switch to if the translation unit doesn't have any 371 /// trampolines that require an executable stack. 372 virtual const MCSection *getNonexecutableStackSection(MCContext &Ctx) const{ 373 return 0; 374 } 375 376 virtual const MCExpr * 377 getExprForPersonalitySymbol(const MCSymbol *Sym, 378 unsigned Encoding, 379 MCStreamer &Streamer) const; 380 381 virtual const MCExpr * 382 getExprForFDESymbol(const MCSymbol *Sym, 383 unsigned Encoding, 384 MCStreamer &Streamer) const; 385 386 bool usesSunStyleELFSectionSwitchSyntax() const { 387 return SunStyleELFSectionSwitchSyntax; 388 } 389 390 bool usesELFSectionDirectiveForBSS() const { 391 return UsesELFSectionDirectiveForBSS; 392 } 393 394 bool hasMicrosoftFastStdCallMangling() const { 395 return HasMicrosoftFastStdCallMangling; 396 } 397 398 bool needsDwarfSectionOffsetDirective() const { 399 return NeedsDwarfSectionOffsetDirective; 400 } 401 402 // Accessors. 403 // 404 bool hasMachoZeroFillDirective() const { return HasMachoZeroFillDirective; } 405 bool hasMachoTBSSDirective() const { return HasMachoTBSSDirective; } 406 bool hasStaticCtorDtorReferenceInStaticMode() const { 407 return HasStaticCtorDtorReferenceInStaticMode; 408 } 409 bool getLinkerRequiresNonEmptyDwarfLines() const { 410 return LinkerRequiresNonEmptyDwarfLines; 411 } 412 unsigned getMaxInstLength() const { 413 return MaxInstLength; 414 } 415 unsigned getMinInstAlignment() const { 416 return MinInstAlignment; 417 } 418 bool getDollarIsPC() const { 419 return DollarIsPC; 420 } 421 const char *getSeparatorString() const { 422 return SeparatorString; 423 } 424 unsigned getCommentColumn() const { 425 return CommentColumn; 426 } 427 const char *getCommentString() const { 428 return CommentString; 429 } 430 const char *getLabelSuffix() const { 431 return LabelSuffix; 432 } 433 434 const char *getDebugLabelSuffix() const { 435 return DebugLabelSuffix; 436 } 437 438 const char *getGlobalPrefix() const { 439 return GlobalPrefix; 440 } 441 const char *getPrivateGlobalPrefix() const { 442 return PrivateGlobalPrefix; 443 } 444 const char *getLinkerPrivateGlobalPrefix() const { 445 return LinkerPrivateGlobalPrefix; 446 } 447 const char *getInlineAsmStart() const { 448 return InlineAsmStart; 449 } 450 const char *getInlineAsmEnd() const { 451 return InlineAsmEnd; 452 } 453 const char *getCode16Directive() const { 454 return Code16Directive; 455 } 456 const char *getCode32Directive() const { 457 return Code32Directive; 458 } 459 const char *getCode64Directive() const { 460 return Code64Directive; 461 } 462 unsigned getAssemblerDialect() const { 463 return AssemblerDialect; 464 } 465 bool doesAllowAtInName() const { 466 return AllowAtInName; 467 } 468 bool doesSupportDataRegionDirectives() const { 469 return UseDataRegionDirectives; 470 } 471 const char *getZeroDirective() const { 472 return ZeroDirective; 473 } 474 const char *getAsciiDirective() const { 475 return AsciiDirective; 476 } 477 const char *getAscizDirective() const { 478 return AscizDirective; 479 } 480 const char *getAlignDirective() const { 481 return AlignDirective; 482 } 483 bool getAlignmentIsInBytes() const { 484 return AlignmentIsInBytes; 485 } 486 unsigned getTextAlignFillValue() const { 487 return TextAlignFillValue; 488 } 489 const char *getGlobalDirective() const { 490 return GlobalDirective; 491 } 492 bool hasSetDirective() const { return HasSetDirective; } 493 bool hasAggressiveSymbolFolding() const { 494 return HasAggressiveSymbolFolding; 495 } 496 bool getCOMMDirectiveAlignmentIsInBytes() const { 497 return COMMDirectiveAlignmentIsInBytes; 498 } 499 LCOMM::LCOMMType getLCOMMDirectiveAlignmentType() const { 500 return LCOMMDirectiveAlignmentType; 501 } 502 bool hasDotTypeDotSizeDirective() const {return HasDotTypeDotSizeDirective;} 503 bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; } 504 bool hasIdentDirective() const { return HasIdentDirective; } 505 bool hasNoDeadStrip() const { return HasNoDeadStrip; } 506 const char *getWeakRefDirective() const { return WeakRefDirective; } 507 bool hasWeakDefDirective() const { return HasWeakDefDirective; } 508 bool hasWeakDefCanBeHiddenDirective() const { 509 return HasWeakDefCanBeHiddenDirective; 510 } 511 bool hasLinkOnceDirective() const { return HasLinkOnceDirective; } 512 513 MCSymbolAttr getHiddenVisibilityAttr() const { return HiddenVisibilityAttr;} 514 MCSymbolAttr getHiddenDeclarationVisibilityAttr() const { 515 return HiddenDeclarationVisibilityAttr; 516 } 517 MCSymbolAttr getProtectedVisibilityAttr() const { 518 return ProtectedVisibilityAttr; 519 } 520 bool hasLEB128() const { 521 return HasLEB128; 522 } 523 bool doesSupportDebugInformation() const { 524 return SupportsDebugInformation; 525 } 526 bool doesSupportExceptionHandling() const { 527 return ExceptionsType != ExceptionHandling::None; 528 } 529 ExceptionHandling::ExceptionsType getExceptionHandlingType() const { 530 return ExceptionsType; 531 } 532 bool isExceptionHandlingDwarf() const { 533 return 534 (ExceptionsType == ExceptionHandling::DwarfCFI || 535 ExceptionsType == ExceptionHandling::ARM || 536 ExceptionsType == ExceptionHandling::Win64); 537 } 538 bool doesDwarfUseRelocationsAcrossSections() const { 539 return DwarfUsesRelocationsAcrossSections; 540 } 541 bool doDwarfFDESymbolsUseAbsDiff() const { 542 return DwarfFDESymbolsUseAbsDiff; 543 } 544 bool useDwarfRegNumForCFI() const { 545 return DwarfRegNumForCFI; 546 } 547 548 void addInitialFrameState(const MCCFIInstruction &Inst) { 549 InitialFrameState.push_back(Inst); 550 } 551 552 const std::vector<MCCFIInstruction> &getInitialFrameState() const { 553 return InitialFrameState; 554 } 555 }; 556} 557 558#endif 559