llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp

   1 //===-- AsmPrinterInlineAsm.cpp - AsmPrinter Inline Asm Handling ----------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the inline assembler pieces of the AsmPrinter class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/ADT/SmallString.h"
  14 #include "llvm/ADT/SmallVector.h"
  15 #include "llvm/ADT/Twine.h"
  16 #include "llvm/CodeGen/AsmPrinter.h"
  17 #include "llvm/CodeGen/MachineBasicBlock.h"
  18 #include "llvm/CodeGen/MachineFunction.h"
  19 #include "llvm/CodeGen/MachineModuleInfo.h"
  20 #include "llvm/CodeGen/TargetInstrInfo.h"
  21 #include "llvm/CodeGen/TargetRegisterInfo.h"
  22 #include "llvm/IR/Constants.h"
  23 #include "llvm/IR/DataLayout.h"
  24 #include "llvm/IR/DiagnosticInfo.h"
  25 #include "llvm/IR/InlineAsm.h"
  26 #include "llvm/IR/LLVMContext.h"
  27 #include "llvm/IR/Module.h"
  28 #include "llvm/MC/MCAsmInfo.h"
  29 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
  30 #include "llvm/MC/MCStreamer.h"
  31 #include "llvm/MC/MCSubtargetInfo.h"
  32 #include "llvm/MC/MCSymbol.h"
  33 #include "llvm/Support/ErrorHandling.h"
  34 #include "llvm/Support/MemoryBuffer.h"
  35 #include "llvm/Support/SourceMgr.h"
  36 #include "llvm/Support/TargetRegistry.h"
  37 #include "llvm/Support/raw_ostream.h"
  38 #include "llvm/Target/TargetMachine.h"
  39 using namespace llvm;
  40
  41 #define DEBUG_TYPE "asm-printer"
  42
  43 unsigned AsmPrinter::addInlineAsmDiagBuffer(StringRef AsmStr,
  44                                             const MDNode *LocMDNode) const {
  45   MCContext &Context = MMI->getContext();
  46   Context.initInlineSourceManager();
  47   SourceMgr &SrcMgr = *Context.getInlineSourceManager();
  48   std::vector<const MDNode *> &LocInfos = Context.getLocInfos();
  49
  50   std::unique_ptr<MemoryBuffer> Buffer;
  51   // The inline asm source manager will outlive AsmStr, so make a copy of the
  52   // string for SourceMgr to own.
  53   Buffer = MemoryBuffer::getMemBufferCopy(AsmStr, "<inline asm>");
  54
  55   // Tell SrcMgr about this buffer, it takes ownership of the buffer.
  56   unsigned BufNum = SrcMgr.AddNewSourceBuffer(std::move(Buffer), SMLoc());
  57
  58   // Store LocMDNode in DiagInfo, using BufNum as an identifier.
  59   if (LocMDNode) {
  60     LocInfos.resize(BufNum);
  61     LocInfos[BufNum - 1] = LocMDNode;
  62   }
  63
  64   return BufNum;
  65 }
  66
  67
  68 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
  69 void AsmPrinter::emitInlineAsm(StringRef Str, const MCSubtargetInfo &STI,
  70                                const MCTargetOptions &MCOptions,
  71                                const MDNode *LocMDNode,
  72                                InlineAsm::AsmDialect Dialect) const {
  73   assert(!Str.empty() && "Can't emit empty inline asm block");
  74
  75   // Remember if the buffer is nul terminated or not so we can avoid a copy.
  76   bool isNullTerminated = Str.back() == 0;
  77   if (isNullTerminated)
  78     Str = Str.substr(0, Str.size()-1);
  79
  80   // If the output streamer does not have mature MC support or the integrated
  81   // assembler has been disabled or not required, just emit the blob textually.
  82   // Otherwise parse the asm and emit it via MC support.
  83   // This is useful in case the asm parser doesn't handle something but the
  84   // system assembler does.
  85   const MCAsmInfo *MCAI = TM.getMCAsmInfo();
  86   assert(MCAI && "No MCAsmInfo");
  87   if (!MCAI->useIntegratedAssembler() &&
  88       !MCAI->parseInlineAsmUsingAsmParser() &&
  89       !OutStreamer->isIntegratedAssemblerRequired()) {
  90     emitInlineAsmStart();
  91     OutStreamer->emitRawText(Str);
  92     emitInlineAsmEnd(STI, nullptr);
  93     return;
  94   }
  95
  96   unsigned BufNum = addInlineAsmDiagBuffer(Str, LocMDNode);
  97   SourceMgr &SrcMgr = *MMI->getContext().getInlineSourceManager();
  98   SrcMgr.setIncludeDirs(MCOptions.IASSearchPaths);
  99
 100   std::unique_ptr<MCAsmParser> Parser(
 101       createMCAsmParser(SrcMgr, OutContext, *OutStreamer, *MAI, BufNum));
 102
 103   // Do not use assembler-level information for parsing inline assembly.
 104   OutStreamer->setUseAssemblerInfoForParsing(false);
 105
 106   // We create a new MCInstrInfo here since we might be at the module level
 107   // and not have a MachineFunction to initialize the TargetInstrInfo from and
 108   // we only need MCInstrInfo for asm parsing. We create one unconditionally
 109   // because it's not subtarget dependent.
 110   std::unique_ptr<MCInstrInfo> MII(TM.getTarget().createMCInstrInfo());
 111   assert(MII && "Failed to create instruction info");
 112   std::unique_ptr<MCTargetAsmParser> TAP(TM.getTarget().createMCAsmParser(
 113       STI, *Parser, *MII, MCOptions));
 114   if (!TAP)
 115     report_fatal_error("Inline asm not supported by this streamer because"
 116                        " we don't have an asm parser for this target\n");
 117   Parser->setAssemblerDialect(Dialect);
 118   Parser->setTargetParser(*TAP.get());
 119   // Enable lexing Masm binary and hex integer literals in intel inline
 120   // assembly.
 121   if (Dialect == InlineAsm::AD_Intel)
 122     Parser->getLexer().setLexMasmIntegers(true);
 123
 124   emitInlineAsmStart();
 125   // Don't implicitly switch to the text section before the asm.
 126   (void)Parser->Run(/*NoInitialTextSection*/ true,
 127                     /*NoFinalize*/ true);
 128   emitInlineAsmEnd(STI, &TAP->getSTI());
 129 }
 130
 131 static void EmitMSInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
 132                                MachineModuleInfo *MMI, AsmPrinter *AP,
 133                                uint64_t LocCookie, raw_ostream &OS) {
 134   // Switch to the inline assembly variant.
 135   OS << "\t.intel_syntax\n\t";
 136
 137   const char *LastEmitted = AsmStr; // One past the last character emitted.
 138   unsigned NumOperands = MI->getNumOperands();
 139
 140   while (*LastEmitted) {
 141     switch (*LastEmitted) {
 142     default: {
 143       // Not a special case, emit the string section literally.
 144       const char *LiteralEnd = LastEmitted+1;
 145       while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
 146              *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
 147         ++LiteralEnd;
 148
 149       OS.write(LastEmitted, LiteralEnd-LastEmitted);
 150       LastEmitted = LiteralEnd;
 151       break;
 152     }
 153     case '\n':
 154       ++LastEmitted;   // Consume newline character.
 155       OS << '\n';      // Indent code with newline.
 156       break;
 157     case '$': {
 158       ++LastEmitted;   // Consume '$' character.
 159       bool Done = true;
 160
 161       // Handle escapes.
 162       switch (*LastEmitted) {
 163       default: Done = false; break;
 164       case '$':
 165         ++LastEmitted;  // Consume second '$' character.
 166         break;
 167       }
 168       if (Done) break;
 169
 170       bool HasCurlyBraces = false;
 171       if (*LastEmitted == '{') {     // ${variable}
 172         ++LastEmitted;               // Consume '{' character.
 173         HasCurlyBraces = true;
 174       }
 175
 176       // If we have ${:foo}, then this is not a real operand reference, it is a
 177       // "magic" string reference, just like in .td files.  Arrange to call
 178       // PrintSpecial.
 179       if (HasCurlyBraces && LastEmitted[0] == ':') {
 180         ++LastEmitted;
 181         const char *StrStart = LastEmitted;
 182         const char *StrEnd = strchr(StrStart, '}');
 183         if (!StrEnd)
 184           report_fatal_error("Unterminated ${:foo} operand in inline asm"
 185                              " string: '" + Twine(AsmStr) + "'");
 186
 187         std::string Val(StrStart, StrEnd);
 188         AP->PrintSpecial(MI, OS, Val.c_str());
 189         LastEmitted = StrEnd+1;
 190         break;
 191       }
 192
 193       const char *IDStart = LastEmitted;
 194       const char *IDEnd = IDStart;
 195       while (isDigit(*IDEnd))
 196         ++IDEnd;
 197
 198       unsigned Val;
 199       if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
 200         report_fatal_error("Bad $ operand number in inline asm string: '" +
 201                            Twine(AsmStr) + "'");
 202       LastEmitted = IDEnd;
 203
 204       if (Val >= NumOperands-1)
 205         report_fatal_error("Invalid $ operand number in inline asm string: '" +
 206                            Twine(AsmStr) + "'");
 207
 208       char Modifier[2] = { 0, 0 };
 209
 210       if (HasCurlyBraces) {
 211         // If we have curly braces, check for a modifier character.  This
 212         // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
 213         if (*LastEmitted == ':') {
 214           ++LastEmitted;    // Consume ':' character.
 215           if (*LastEmitted == 0)
 216             report_fatal_error("Bad ${:} expression in inline asm string: '" +
 217                                Twine(AsmStr) + "'");
 218
 219           Modifier[0] = *LastEmitted;
 220           ++LastEmitted;    // Consume modifier character.
 221         }
 222
 223         if (*LastEmitted != '}')
 224           report_fatal_error("Bad ${} expression in inline asm string: '" +
 225                              Twine(AsmStr) + "'");
 226         ++LastEmitted;    // Consume '}' character.
 227       }
 228
 229       // Okay, we finally have a value number.  Ask the target to print this
 230       // operand!
 231       unsigned OpNo = InlineAsm::MIOp_FirstOperand;
 232
 233       bool Error = false;
 234
 235       // Scan to find the machine operand number for the operand.
 236       for (; Val; --Val) {
 237         if (OpNo >= MI->getNumOperands()) break;
 238         unsigned OpFlags = MI->getOperand(OpNo).getImm();
 239         OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
 240       }
 241
 242       // We may have a location metadata attached to the end of the
 243       // instruction, and at no point should see metadata at any
 244       // other point while processing. It's an error if so.
 245       if (OpNo >= MI->getNumOperands() ||
 246           MI->getOperand(OpNo).isMetadata()) {
 247         Error = true;
 248       } else {
 249         unsigned OpFlags = MI->getOperand(OpNo).getImm();
 250         ++OpNo;  // Skip over the ID number.
 251
 252         if (InlineAsm::isMemKind(OpFlags)) {
 253           Error = AP->PrintAsmMemoryOperand(
 254               MI, OpNo, Modifier[0] ? Modifier : nullptr, OS);
 255         } else {
 256           Error = AP->PrintAsmOperand(MI, OpNo,
 257                                       Modifier[0] ? Modifier : nullptr, OS);
 258         }
 259       }
 260       if (Error) {
 261         std::string msg;
 262         raw_string_ostream Msg(msg);
 263         Msg << "invalid operand in inline asm: '" << AsmStr << "'";
 264         MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
 265       }
 266       break;
 267     }
 268     }
 269   }
 270   OS << "\n\t.att_syntax\n" << (char)0;  // null terminate string.
 271 }
 272
 273 static void EmitGCCInlineAsmStr(const char *AsmStr, const MachineInstr *MI,
 274                                 MachineModuleInfo *MMI, const MCAsmInfo *MAI,
 275                                 AsmPrinter *AP, uint64_t LocCookie,
 276                                 raw_ostream &OS) {
 277   int CurVariant = -1;            // The number of the {.|.|.} region we are in.
 278   const char *LastEmitted = AsmStr; // One past the last character emitted.
 279   unsigned NumOperands = MI->getNumOperands();
 280   int AsmPrinterVariant = MAI->getAssemblerDialect();
 281
 282   if (MAI->getEmitGNUAsmStartIndentationMarker())
 283     OS << '\t';
 284
 285   while (*LastEmitted) {
 286     switch (*LastEmitted) {
 287     default: {
 288       // Not a special case, emit the string section literally.
 289       const char *LiteralEnd = LastEmitted+1;
 290       while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
 291              *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
 292         ++LiteralEnd;
 293       if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
 294         OS.write(LastEmitted, LiteralEnd-LastEmitted);
 295       LastEmitted = LiteralEnd;
 296       break;
 297     }
 298     case '\n':
 299       ++LastEmitted;   // Consume newline character.
 300       OS << '\n';      // Indent code with newline.
 301       break;
 302     case '$': {
 303       ++LastEmitted;   // Consume '$' character.
 304       bool Done = true;
 305
 306       // Handle escapes.
 307       switch (*LastEmitted) {
 308       default: Done = false; break;
 309       case '$':     // $$ -> $
 310         if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
 311           OS << '$';
 312         ++LastEmitted;  // Consume second '$' character.
 313         break;
 314       case '(':             // $( -> same as GCC's { character.
 315         ++LastEmitted;      // Consume '(' character.
 316         if (CurVariant != -1)
 317           report_fatal_error("Nested variants found in inline asm string: '" +
 318                              Twine(AsmStr) + "'");
 319         CurVariant = 0;     // We're in the first variant now.
 320         break;
 321       case '|':
 322         ++LastEmitted;  // consume '|' character.
 323         if (CurVariant == -1)
 324           OS << '|';       // this is gcc's behavior for | outside a variant
 325         else
 326           ++CurVariant;   // We're in the next variant.
 327         break;
 328       case ')':         // $) -> same as GCC's } char.
 329         ++LastEmitted;  // consume ')' character.
 330         if (CurVariant == -1)
 331           OS << '}';     // this is gcc's behavior for } outside a variant
 332         else
 333           CurVariant = -1;
 334         break;
 335       }
 336       if (Done) break;
 337
 338       bool HasCurlyBraces = false;
 339       if (*LastEmitted == '{') {     // ${variable}
 340         ++LastEmitted;               // Consume '{' character.
 341         HasCurlyBraces = true;
 342       }
 343
 344       // If we have ${:foo}, then this is not a real operand reference, it is a
 345       // "magic" string reference, just like in .td files.  Arrange to call
 346       // PrintSpecial.
 347       if (HasCurlyBraces && *LastEmitted == ':') {
 348         ++LastEmitted;
 349         const char *StrStart = LastEmitted;
 350         const char *StrEnd = strchr(StrStart, '}');
 351         if (!StrEnd)
 352           report_fatal_error("Unterminated ${:foo} operand in inline asm"
 353                              " string: '" + Twine(AsmStr) + "'");
 354
 355         std::string Val(StrStart, StrEnd);
 356         AP->PrintSpecial(MI, OS, Val.c_str());
 357         LastEmitted = StrEnd+1;
 358         break;
 359       }
 360
 361       const char *IDStart = LastEmitted;
 362       const char *IDEnd = IDStart;
 363       while (isDigit(*IDEnd))
 364         ++IDEnd;
 365
 366       unsigned Val;
 367       if (StringRef(IDStart, IDEnd-IDStart).getAsInteger(10, Val))
 368         report_fatal_error("Bad $ operand number in inline asm string: '" +
 369                            Twine(AsmStr) + "'");
 370       LastEmitted = IDEnd;
 371
 372       char Modifier[2] = { 0, 0 };
 373
 374       if (HasCurlyBraces) {
 375         // If we have curly braces, check for a modifier character.  This
 376         // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
 377         if (*LastEmitted == ':') {
 378           ++LastEmitted;    // Consume ':' character.
 379           if (*LastEmitted == 0)
 380             report_fatal_error("Bad ${:} expression in inline asm string: '" +
 381                                Twine(AsmStr) + "'");
 382
 383           Modifier[0] = *LastEmitted;
 384           ++LastEmitted;    // Consume modifier character.
 385         }
 386
 387         if (*LastEmitted != '}')
 388           report_fatal_error("Bad ${} expression in inline asm string: '" +
 389                              Twine(AsmStr) + "'");
 390         ++LastEmitted;    // Consume '}' character.
 391       }
 392
 393       if (Val >= NumOperands-1)
 394         report_fatal_error("Invalid $ operand number in inline asm string: '" +
 395                            Twine(AsmStr) + "'");
 396
 397       // Okay, we finally have a value number.  Ask the target to print this
 398       // operand!
 399       if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
 400         unsigned OpNo = InlineAsm::MIOp_FirstOperand;
 401
 402         bool Error = false;
 403
 404         // Scan to find the machine operand number for the operand.
 405         for (; Val; --Val) {
 406           if (OpNo >= MI->getNumOperands()) break;
 407           unsigned OpFlags = MI->getOperand(OpNo).getImm();
 408           OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
 409         }
 410
 411         // We may have a location metadata attached to the end of the
 412         // instruction, and at no point should see metadata at any
 413         // other point while processing. It's an error if so.
 414         if (OpNo >= MI->getNumOperands() ||
 415             MI->getOperand(OpNo).isMetadata()) {
 416           Error = true;
 417         } else {
 418           unsigned OpFlags = MI->getOperand(OpNo).getImm();
 419           ++OpNo;  // Skip over the ID number.
 420
 421           // FIXME: Shouldn't arch-independent output template handling go into
 422           // PrintAsmOperand?
 423           // Labels are target independent.
 424           if (MI->getOperand(OpNo).isBlockAddress()) {
 425             const BlockAddress *BA = MI->getOperand(OpNo).getBlockAddress();
 426             MCSymbol *Sym = AP->GetBlockAddressSymbol(BA);
 427             Sym->print(OS, AP->MAI);
 428             MMI->getContext().registerInlineAsmLabel(Sym);
 429           } else if (MI->getOperand(OpNo).isMBB()) {
 430             const MCSymbol *Sym = MI->getOperand(OpNo).getMBB()->getSymbol();
 431             Sym->print(OS, AP->MAI);
 432           } else if (Modifier[0] == 'l') {
 433             Error = true;
 434           } else if (InlineAsm::isMemKind(OpFlags)) {
 435             Error = AP->PrintAsmMemoryOperand(
 436                 MI, OpNo, Modifier[0] ? Modifier : nullptr, OS);
 437           } else {
 438             Error = AP->PrintAsmOperand(MI, OpNo,
 439                                         Modifier[0] ? Modifier : nullptr, OS);
 440           }
 441         }
 442         if (Error) {
 443           std::string msg;
 444           raw_string_ostream Msg(msg);
 445           Msg << "invalid operand in inline asm: '" << AsmStr << "'";
 446           MMI->getModule()->getContext().emitError(LocCookie, Msg.str());
 447         }
 448       }
 449       break;
 450     }
 451     }
 452   }
 453   OS << '\n' << (char)0;  // null terminate string.
 454 }
 455
 456 /// This method formats and emits the specified machine instruction that is an
 457 /// inline asm.
 458 void AsmPrinter::emitInlineAsm(const MachineInstr *MI) const {
 459   assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
 460
 461   // Count the number of register definitions to find the asm string.
 462   unsigned NumDefs = 0;
 463   for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
 464        ++NumDefs)
 465     assert(NumDefs != MI->getNumOperands()-2 && "No asm string?");
 466
 467   assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
 468
 469   // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
 470   const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
 471
 472   // If this asmstr is empty, just print the #APP/#NOAPP markers.
 473   // These are useful to see where empty asm's wound up.
 474   if (AsmStr[0] == 0) {
 475     OutStreamer->emitRawComment(MAI->getInlineAsmStart());
 476     OutStreamer->emitRawComment(MAI->getInlineAsmEnd());
 477     return;
 478   }
 479
 480   // Emit the #APP start marker.  This has to happen even if verbose-asm isn't
 481   // enabled, so we use emitRawComment.
 482   OutStreamer->emitRawComment(MAI->getInlineAsmStart());
 483
 484   // Get the !srcloc metadata node if we have it, and decode the loc cookie from
 485   // it.
 486   uint64_t LocCookie = 0;
 487   const MDNode *LocMD = nullptr;
 488   for (unsigned i = MI->getNumOperands(); i != 0; --i) {
 489     if (MI->getOperand(i-1).isMetadata() &&
 490         (LocMD = MI->getOperand(i-1).getMetadata()) &&
 491         LocMD->getNumOperands() != 0) {
 492       if (const ConstantInt *CI =
 493               mdconst::dyn_extract<ConstantInt>(LocMD->getOperand(0))) {
 494         LocCookie = CI->getZExtValue();
 495         break;
 496       }
 497     }
 498   }
 499
 500   // Emit the inline asm to a temporary string so we can emit it through
 501   // EmitInlineAsm.
 502   SmallString<256> StringData;
 503   raw_svector_ostream OS(StringData);
 504
 505   AsmPrinter *AP = const_cast<AsmPrinter*>(this);
 506   if (MI->getInlineAsmDialect() == InlineAsm::AD_ATT)
 507     EmitGCCInlineAsmStr(AsmStr, MI, MMI, MAI, AP, LocCookie, OS);
 508   else
 509     EmitMSInlineAsmStr(AsmStr, MI, MMI, AP, LocCookie, OS);
 510
 511   // Emit warnings if we use reserved registers on the clobber list, as
 512   // that might lead to undefined behaviour.
 513   SmallVector<Register, 8> RestrRegs;
 514   const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
 515   // Start with the first operand descriptor, and iterate over them.
 516   for (unsigned I = InlineAsm::MIOp_FirstOperand, NumOps = MI->getNumOperands();
 517        I < NumOps; ++I) {
 518     const MachineOperand &MO = MI->getOperand(I);
 519     if (!MO.isImm())
 520       continue;
 521     unsigned Flags = MO.getImm();
 522     if (InlineAsm::getKind(Flags) == InlineAsm::Kind_Clobber) {
 523       Register Reg = MI->getOperand(I + 1).getReg();
 524       if (!TRI->isAsmClobberable(*MF, Reg))
 525         RestrRegs.push_back(Reg);
 526     }
 527     // Skip to one before the next operand descriptor, if it exists.
 528     I += InlineAsm::getNumOperandRegisters(Flags);
 529   }
 530
 531   if (!RestrRegs.empty()) {
 532     std::string Msg = "inline asm clobber list contains reserved registers: ";
 533     ListSeparator LS;
 534     for (const Register &RR : RestrRegs) {
 535       Msg += LS;
 536       Msg += TRI->getName(RR);
 537     }
 538     const char *Note =
 539         "Reserved registers on the clobber list may not be "
 540         "preserved across the asm statement, and clobbering them may "
 541         "lead to undefined behaviour.";
 542     MMI->getModule()->getContext().diagnose(DiagnosticInfoInlineAsm(
 543         LocCookie, Msg.c_str(), DiagnosticSeverity::DS_Warning));
 544     MMI->getModule()->getContext().diagnose(
 545         DiagnosticInfoInlineAsm(LocCookie, Note, DiagnosticSeverity::DS_Note));
 546   }
 547
 548   emitInlineAsm(OS.str(), getSubtargetInfo(), TM.Options.MCOptions, LocMD,
 549                 MI->getInlineAsmDialect());
 550
 551   // Emit the #NOAPP end marker.  This has to happen even if verbose-asm isn't
 552   // enabled, so we use emitRawComment.
 553   OutStreamer->emitRawComment(MAI->getInlineAsmEnd());
 554 }
 555
 556 /// PrintSpecial - Print information related to the specified machine instr
 557 /// that is independent of the operand, and may be independent of the instr
 558 /// itself.  This can be useful for portably encoding the comment character
 559 /// or other bits of target-specific knowledge into the asmstrings.  The
 560 /// syntax used is ${:comment}.  Targets can override this to add support
 561 /// for their own strange codes.
 562 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
 563                               const char *Code) const {
 564   if (!strcmp(Code, "private")) {
 565     const DataLayout &DL = MF->getDataLayout();
 566     OS << DL.getPrivateGlobalPrefix();
 567   } else if (!strcmp(Code, "comment")) {
 568     OS << MAI->getCommentString();
 569   } else if (!strcmp(Code, "uid")) {
 570     // Comparing the address of MI isn't sufficient, because machineinstrs may
 571     // be allocated to the same address across functions.
 572
 573     // If this is a new LastFn instruction, bump the counter.
 574     if (LastMI != MI || LastFn != getFunctionNumber()) {
 575       ++Counter;
 576       LastMI = MI;
 577       LastFn = getFunctionNumber();
 578     }
 579     OS << Counter;
 580   } else {
 581     std::string msg;
 582     raw_string_ostream Msg(msg);
 583     Msg << "Unknown special formatter '" << Code
 584          << "' for machine instr: " << *MI;
 585     report_fatal_error(Msg.str());
 586   }
 587 }
 588
 589 void AsmPrinter::PrintSymbolOperand(const MachineOperand &MO, raw_ostream &OS) {
 590   assert(MO.isGlobal() && "caller should check MO.isGlobal");
 591   getSymbolPreferLocal(*MO.getGlobal())->print(OS, MAI);
 592   printOffset(MO.getOffset(), OS);
 593 }
 594
 595 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
 596 /// instruction, using the specified assembler variant.  Targets should
 597 /// override this to format as appropriate for machine specific ExtraCodes
 598 /// or when the arch-independent handling would be too complex otherwise.
 599 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
 600                                  const char *ExtraCode, raw_ostream &O) {
 601   // Does this asm operand have a single letter operand modifier?
 602   if (ExtraCode && ExtraCode[0]) {
 603     if (ExtraCode[1] != 0) return true; // Unknown modifier.
 604
 605     // https://gcc.gnu.org/onlinedocs/gccint/Output-Template.html
 606     const MachineOperand &MO = MI->getOperand(OpNo);
 607     switch (ExtraCode[0]) {
 608     default:
 609       return true;  // Unknown modifier.
 610     case 'a': // Print as memory address.
 611       if (MO.isReg()) {
 612         PrintAsmMemoryOperand(MI, OpNo, nullptr, O);
 613         return false;
 614       }
 615       LLVM_FALLTHROUGH; // GCC allows '%a' to behave like '%c' with immediates.
 616     case 'c': // Substitute immediate value without immediate syntax
 617       if (MO.isImm()) {
 618         O << MO.getImm();
 619         return false;
 620       }
 621       if (MO.isGlobal()) {
 622         PrintSymbolOperand(MO, O);
 623         return false;
 624       }
 625       return true;
 626     case 'n':  // Negate the immediate constant.
 627       if (!MO.isImm())
 628         return true;
 629       O << -MO.getImm();
 630       return false;
 631     case 's':  // The GCC deprecated s modifier
 632       if (!MO.isImm())
 633         return true;
 634       O << ((32 - MO.getImm()) & 31);
 635       return false;
 636     }
 637   }
 638   return true;
 639 }
 640
 641 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
 642                                        const char *ExtraCode, raw_ostream &O) {
 643   // Target doesn't support this yet!
 644   return true;
 645 }
 646
 647 void AsmPrinter::emitInlineAsmStart() const {}
 648
 649 void AsmPrinter::emitInlineAsmEnd(const MCSubtargetInfo &StartInfo,
 650                                   const MCSubtargetInfo *EndInfo) const {}