utils/TableGen/TGParser.cpp

   1 //===- TGParser.cpp - Parser for TableGen Files ---------------------------===//
   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 // Implement the Parser for TableGen.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "TGParser.h"
  15 #include "Record.h"
  16 #include "llvm/ADT/StringExtras.h"
  17 #include <algorithm>
  18 #include <sstream>
  19 #include "llvm/ADT/SmallVector.h"
  20 #include "llvm/Support/CommandLine.h"
  21 using namespace llvm;
  22
  23 //===----------------------------------------------------------------------===//
  24 // Support Code for the Semantic Actions.
  25 //===----------------------------------------------------------------------===//
  26
  27 namespace llvm {
  28 struct SubClassReference {
  29   SMLoc RefLoc;
  30   Record *Rec;
  31   std::vector<Init*> TemplateArgs;
  32   SubClassReference() : Rec(0) {}
  33
  34   bool isInvalid() const { return Rec == 0; }
  35 };
  36
  37 struct SubMultiClassReference {
  38   SMLoc RefLoc;
  39   MultiClass *MC;
  40   std::vector<Init*> TemplateArgs;
  41   SubMultiClassReference() : MC(0) {}
  42
  43   bool isInvalid() const { return MC == 0; }
  44   void dump() const;
  45 };
  46
  47 void SubMultiClassReference::dump() const {
  48   errs() << "Multiclass:\n";
  49
  50   MC->dump();
  51
  52   errs() << "Template args:\n";
  53   for (std::vector<Init *>::const_iterator i = TemplateArgs.begin(),
  54          iend = TemplateArgs.end();
  55        i != iend;
  56        ++i) {
  57     (*i)->dump();
  58   }
  59 }
  60
  61 } // end namespace llvm
  62
  63 bool TGParser::AddValue(Record *CurRec, SMLoc Loc, const RecordVal &RV) {
  64   if (CurRec == 0)
  65     CurRec = &CurMultiClass->Rec;
  66
  67   if (RecordVal *ERV = CurRec->getValue(RV.getName())) {
  68     // The value already exists in the class, treat this as a set.
  69     if (ERV->setValue(RV.getValue()))
  70       return Error(Loc, "New definition of '" + RV.getName() + "' of type '" +
  71                    RV.getType()->getAsString() + "' is incompatible with " +
  72                    "previous definition of type '" +
  73                    ERV->getType()->getAsString() + "'");
  74   } else {
  75     CurRec->addValue(RV);
  76   }
  77   return false;
  78 }
  79
  80 /// SetValue -
  81 /// Return true on error, false on success.
  82 bool TGParser::SetValue(Record *CurRec, SMLoc Loc, const std::string &ValName,
  83                         const std::vector<unsigned> &BitList, Init *V) {
  84   if (!V) return false;
  85
  86   if (CurRec == 0) CurRec = &CurMultiClass->Rec;
  87
  88   RecordVal *RV = CurRec->getValue(ValName);
  89   if (RV == 0)
  90     return Error(Loc, "Value '" + ValName + "' unknown!");
  91
  92   // Do not allow assignments like 'X = X'.  This will just cause infinite loops
  93   // in the resolution machinery.
  94   if (BitList.empty())
  95     if (VarInit *VI = dynamic_cast<VarInit*>(V))
  96       if (VI->getName() == ValName)
  97         return false;
  98
  99   // If we are assigning to a subset of the bits in the value... then we must be
 100   // assigning to a field of BitsRecTy, which must have a BitsInit
 101   // initializer.
 102   //
 103   if (!BitList.empty()) {
 104     BitsInit *CurVal = dynamic_cast<BitsInit*>(RV->getValue());
 105     if (CurVal == 0)
 106       return Error(Loc, "Value '" + ValName + "' is not a bits type");
 107
 108     // Convert the incoming value to a bits type of the appropriate size...
 109     Init *BI = V->convertInitializerTo(new BitsRecTy(BitList.size()));
 110     if (BI == 0) {
 111       V->convertInitializerTo(new BitsRecTy(BitList.size()));
 112       return Error(Loc, "Initializer is not compatible with bit range");
 113     }
 114
 115     // We should have a BitsInit type now.
 116     BitsInit *BInit = dynamic_cast<BitsInit*>(BI);
 117     assert(BInit != 0);
 118
 119     BitsInit *NewVal = new BitsInit(CurVal->getNumBits());
 120
 121     // Loop over bits, assigning values as appropriate.
 122     for (unsigned i = 0, e = BitList.size(); i != e; ++i) {
 123       unsigned Bit = BitList[i];
 124       if (NewVal->getBit(Bit))
 125         return Error(Loc, "Cannot set bit #" + utostr(Bit) + " of value '" +
 126                      ValName + "' more than once");
 127       NewVal->setBit(Bit, BInit->getBit(i));
 128     }
 129
 130     for (unsigned i = 0, e = CurVal->getNumBits(); i != e; ++i)
 131       if (NewVal->getBit(i) == 0)
 132         NewVal->setBit(i, CurVal->getBit(i));
 133
 134     V = NewVal;
 135   }
 136
 137   if (RV->setValue(V))
 138    return Error(Loc, "Value '" + ValName + "' of type '" +
 139                 RV->getType()->getAsString() +
 140                 "' is incompatible with initializer '" + V->getAsString() +"'");
 141   return false;
 142 }
 143
 144 /// AddSubClass - Add SubClass as a subclass to CurRec, resolving its template
 145 /// args as SubClass's template arguments.
 146 bool TGParser::AddSubClass(Record *CurRec, SubClassReference &SubClass) {
 147   Record *SC = SubClass.Rec;
 148   // Add all of the values in the subclass into the current class.
 149   const std::vector<RecordVal> &Vals = SC->getValues();
 150   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 151     if (AddValue(CurRec, SubClass.RefLoc, Vals[i]))
 152       return true;
 153
 154   const std::vector<std::string> &TArgs = SC->getTemplateArgs();
 155
 156   // Ensure that an appropriate number of template arguments are specified.
 157   if (TArgs.size() < SubClass.TemplateArgs.size())
 158     return Error(SubClass.RefLoc, "More template args specified than expected");
 159
 160   // Loop over all of the template arguments, setting them to the specified
 161   // value or leaving them as the default if necessary.
 162   for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
 163     if (i < SubClass.TemplateArgs.size()) {
 164       // If a value is specified for this template arg, set it now.
 165       if (SetValue(CurRec, SubClass.RefLoc, TArgs[i], std::vector<unsigned>(),
 166                    SubClass.TemplateArgs[i]))
 167         return true;
 168
 169       // Resolve it next.
 170       CurRec->resolveReferencesTo(CurRec->getValue(TArgs[i]));
 171
 172       // Now remove it.
 173       CurRec->removeValue(TArgs[i]);
 174
 175     } else if (!CurRec->getValue(TArgs[i])->getValue()->isComplete()) {
 176       return Error(SubClass.RefLoc,"Value not specified for template argument #"
 177                    + utostr(i) + " (" + TArgs[i] + ") of subclass '" +
 178                    SC->getName() + "'!");
 179     }
 180   }
 181
 182   // Since everything went well, we can now set the "superclass" list for the
 183   // current record.
 184   const std::vector<Record*> &SCs = SC->getSuperClasses();
 185   for (unsigned i = 0, e = SCs.size(); i != e; ++i) {
 186     if (CurRec->isSubClassOf(SCs[i]))
 187       return Error(SubClass.RefLoc,
 188                    "Already subclass of '" + SCs[i]->getName() + "'!\n");
 189     CurRec->addSuperClass(SCs[i]);
 190   }
 191
 192   if (CurRec->isSubClassOf(SC))
 193     return Error(SubClass.RefLoc,
 194                  "Already subclass of '" + SC->getName() + "'!\n");
 195   CurRec->addSuperClass(SC);
 196   return false;
 197 }
 198
 199 /// AddSubMultiClass - Add SubMultiClass as a subclass to
 200 /// CurMC, resolving its template args as SubMultiClass's
 201 /// template arguments.
 202 bool TGParser::AddSubMultiClass(MultiClass *CurMC,
 203                                 SubMultiClassReference &SubMultiClass) {
 204   MultiClass *SMC = SubMultiClass.MC;
 205   Record *CurRec = &CurMC->Rec;
 206
 207   const std::vector<RecordVal> &MCVals = CurRec->getValues();
 208
 209   // Add all of the values in the subclass into the current class.
 210   const std::vector<RecordVal> &SMCVals = SMC->Rec.getValues();
 211   for (unsigned i = 0, e = SMCVals.size(); i != e; ++i)
 212     if (AddValue(CurRec, SubMultiClass.RefLoc, SMCVals[i]))
 213       return true;
 214
 215   int newDefStart = CurMC->DefPrototypes.size();
 216
 217   // Add all of the defs in the subclass into the current multiclass.
 218   for (MultiClass::RecordVector::const_iterator i = SMC->DefPrototypes.begin(),
 219          iend = SMC->DefPrototypes.end();
 220        i != iend;
 221        ++i) {
 222     // Clone the def and add it to the current multiclass
 223     Record *NewDef = new Record(**i);
 224
 225     // Add all of the values in the superclass into the current def.
 226     for (unsigned i = 0, e = MCVals.size(); i != e; ++i)
 227       if (AddValue(NewDef, SubMultiClass.RefLoc, MCVals[i]))
 228         return true;
 229
 230     CurMC->DefPrototypes.push_back(NewDef);
 231   }
 232
 233   const std::vector<std::string> &SMCTArgs = SMC->Rec.getTemplateArgs();
 234
 235   // Ensure that an appropriate number of template arguments are
 236   // specified.
 237   if (SMCTArgs.size() < SubMultiClass.TemplateArgs.size())
 238     return Error(SubMultiClass.RefLoc,
 239                  "More template args specified than expected");
 240
 241   // Loop over all of the template arguments, setting them to the specified
 242   // value or leaving them as the default if necessary.
 243   for (unsigned i = 0, e = SMCTArgs.size(); i != e; ++i) {
 244     if (i < SubMultiClass.TemplateArgs.size()) {
 245       // If a value is specified for this template arg, set it in the
 246       // superclass now.
 247       if (SetValue(CurRec, SubMultiClass.RefLoc, SMCTArgs[i],
 248                    std::vector<unsigned>(),
 249                    SubMultiClass.TemplateArgs[i]))
 250         return true;
 251
 252       // Resolve it next.
 253       CurRec->resolveReferencesTo(CurRec->getValue(SMCTArgs[i]));
 254
 255       // Now remove it.
 256       CurRec->removeValue(SMCTArgs[i]);
 257
 258       // If a value is specified for this template arg, set it in the
 259       // new defs now.
 260       for (MultiClass::RecordVector::iterator j =
 261              CurMC->DefPrototypes.begin() + newDefStart,
 262              jend = CurMC->DefPrototypes.end();
 263            j != jend;
 264            ++j) {
 265         Record *Def = *j;
 266
 267         if (SetValue(Def, SubMultiClass.RefLoc, SMCTArgs[i],
 268                      std::vector<unsigned>(),
 269                      SubMultiClass.TemplateArgs[i]))
 270           return true;
 271
 272         // Resolve it next.
 273         Def->resolveReferencesTo(Def->getValue(SMCTArgs[i]));
 274
 275         // Now remove it
 276         Def->removeValue(SMCTArgs[i]);
 277       }
 278     } else if (!CurRec->getValue(SMCTArgs[i])->getValue()->isComplete()) {
 279       return Error(SubMultiClass.RefLoc,
 280                    "Value not specified for template argument #"
 281                    + utostr(i) + " (" + SMCTArgs[i] + ") of subclass '" +
 282                    SMC->Rec.getName() + "'!");
 283     }
 284   }
 285
 286   return false;
 287 }
 288
 289 //===----------------------------------------------------------------------===//
 290 // Parser Code
 291 //===----------------------------------------------------------------------===//
 292
 293 /// isObjectStart - Return true if this is a valid first token for an Object.
 294 static bool isObjectStart(tgtok::TokKind K) {
 295   return K == tgtok::Class || K == tgtok::Def ||
 296          K == tgtok::Defm || K == tgtok::Let || K == tgtok::MultiClass;
 297 }
 298
 299 static std::string GetNewAnonymousName() {
 300   static unsigned AnonCounter = 0;
 301   return "anonymous."+utostr(AnonCounter++);
 302 }
 303
 304 /// ParseObjectName - If an object name is specified, return it.  Otherwise,
 305 /// return an anonymous name.
 306 ///   ObjectName ::= ID
 307 ///   ObjectName ::= /*empty*/
 308 ///
 309 std::string TGParser::ParseObjectName() {
 310   if (Lex.getCode() != tgtok::Id)
 311     return GetNewAnonymousName();
 312
 313   std::string Ret = Lex.getCurStrVal();
 314   Lex.Lex();
 315   return Ret;
 316 }
 317
 318
 319 /// ParseClassID - Parse and resolve a reference to a class name.  This returns
 320 /// null on error.
 321 ///
 322 ///    ClassID ::= ID
 323 ///
 324 Record *TGParser::ParseClassID() {
 325   if (Lex.getCode() != tgtok::Id) {
 326     TokError("expected name for ClassID");
 327     return 0;
 328   }
 329
 330   Record *Result = Records.getClass(Lex.getCurStrVal());
 331   if (Result == 0)
 332     TokError("Couldn't find class '" + Lex.getCurStrVal() + "'");
 333
 334   Lex.Lex();
 335   return Result;
 336 }
 337
 338 /// ParseMultiClassID - Parse and resolve a reference to a multiclass name.
 339 /// This returns null on error.
 340 ///
 341 ///    MultiClassID ::= ID
 342 ///
 343 MultiClass *TGParser::ParseMultiClassID() {
 344   if (Lex.getCode() != tgtok::Id) {
 345     TokError("expected name for ClassID");
 346     return 0;
 347   }
 348
 349   MultiClass *Result = MultiClasses[Lex.getCurStrVal()];
 350   if (Result == 0)
 351     TokError("Couldn't find class '" + Lex.getCurStrVal() + "'");
 352
 353   Lex.Lex();
 354   return Result;
 355 }
 356
 357 Record *TGParser::ParseDefmID() {
 358   if (Lex.getCode() != tgtok::Id) {
 359     TokError("expected multiclass name");
 360     return 0;
 361   }
 362
 363   MultiClass *MC = MultiClasses[Lex.getCurStrVal()];
 364   if (MC == 0) {
 365     TokError("Couldn't find multiclass '" + Lex.getCurStrVal() + "'");
 366     return 0;
 367   }
 368
 369   Lex.Lex();
 370   return &MC->Rec;
 371 }
 372
 373
 374 /// ParseSubClassReference - Parse a reference to a subclass or to a templated
 375 /// subclass.  This returns a SubClassRefTy with a null Record* on error.
 376 ///
 377 ///  SubClassRef ::= ClassID
 378 ///  SubClassRef ::= ClassID '<' ValueList '>'
 379 ///
 380 SubClassReference TGParser::
 381 ParseSubClassReference(Record *CurRec, bool isDefm) {
 382   SubClassReference Result;
 383   Result.RefLoc = Lex.getLoc();
 384
 385   if (isDefm)
 386     Result.Rec = ParseDefmID();
 387   else
 388     Result.Rec = ParseClassID();
 389   if (Result.Rec == 0) return Result;
 390
 391   // If there is no template arg list, we're done.
 392   if (Lex.getCode() != tgtok::less)
 393     return Result;
 394   Lex.Lex();  // Eat the '<'
 395
 396   if (Lex.getCode() == tgtok::greater) {
 397     TokError("subclass reference requires a non-empty list of template values");
 398     Result.Rec = 0;
 399     return Result;
 400   }
 401
 402   Result.TemplateArgs = ParseValueList(CurRec, Result.Rec);
 403   if (Result.TemplateArgs.empty()) {
 404     Result.Rec = 0;   // Error parsing value list.
 405     return Result;
 406   }
 407
 408   if (Lex.getCode() != tgtok::greater) {
 409     TokError("expected '>' in template value list");
 410     Result.Rec = 0;
 411     return Result;
 412   }
 413   Lex.Lex();
 414
 415   return Result;
 416 }
 417
 418 /// ParseSubMultiClassReference - Parse a reference to a subclass or to a
 419 /// templated submulticlass.  This returns a SubMultiClassRefTy with a null
 420 /// Record* on error.
 421 ///
 422 ///  SubMultiClassRef ::= MultiClassID
 423 ///  SubMultiClassRef ::= MultiClassID '<' ValueList '>'
 424 ///
 425 SubMultiClassReference TGParser::
 426 ParseSubMultiClassReference(MultiClass *CurMC) {
 427   SubMultiClassReference Result;
 428   Result.RefLoc = Lex.getLoc();
 429
 430   Result.MC = ParseMultiClassID();
 431   if (Result.MC == 0) return Result;
 432
 433   // If there is no template arg list, we're done.
 434   if (Lex.getCode() != tgtok::less)
 435     return Result;
 436   Lex.Lex();  // Eat the '<'
 437
 438   if (Lex.getCode() == tgtok::greater) {
 439     TokError("subclass reference requires a non-empty list of template values");
 440     Result.MC = 0;
 441     return Result;
 442   }
 443
 444   Result.TemplateArgs = ParseValueList(&CurMC->Rec, &Result.MC->Rec);
 445   if (Result.TemplateArgs.empty()) {
 446     Result.MC = 0;   // Error parsing value list.
 447     return Result;
 448   }
 449
 450   if (Lex.getCode() != tgtok::greater) {
 451     TokError("expected '>' in template value list");
 452     Result.MC = 0;
 453     return Result;
 454   }
 455   Lex.Lex();
 456
 457   return Result;
 458 }
 459
 460 /// ParseRangePiece - Parse a bit/value range.
 461 ///   RangePiece ::= INTVAL
 462 ///   RangePiece ::= INTVAL '-' INTVAL
 463 ///   RangePiece ::= INTVAL INTVAL
 464 bool TGParser::ParseRangePiece(std::vector<unsigned> &Ranges) {
 465   if (Lex.getCode() != tgtok::IntVal) {
 466     TokError("expected integer or bitrange");
 467     return true;
 468   }
 469   int64_t Start = Lex.getCurIntVal();
 470   int64_t End;
 471
 472   if (Start < 0)
 473     return TokError("invalid range, cannot be negative");
 474
 475   switch (Lex.Lex()) {  // eat first character.
 476   default:
 477     Ranges.push_back(Start);
 478     return false;
 479   case tgtok::minus:
 480     if (Lex.Lex() != tgtok::IntVal) {
 481       TokError("expected integer value as end of range");
 482       return true;
 483     }
 484     End = Lex.getCurIntVal();
 485     break;
 486   case tgtok::IntVal:
 487     End = -Lex.getCurIntVal();
 488     break;
 489   }
 490   if (End < 0)
 491     return TokError("invalid range, cannot be negative");
 492   Lex.Lex();
 493
 494   // Add to the range.
 495   if (Start < End) {
 496     for (; Start <= End; ++Start)
 497       Ranges.push_back(Start);
 498   } else {
 499     for (; Start >= End; --Start)
 500       Ranges.push_back(Start);
 501   }
 502   return false;
 503 }
 504
 505 /// ParseRangeList - Parse a list of scalars and ranges into scalar values.
 506 ///
 507 ///   RangeList ::= RangePiece (',' RangePiece)*
 508 ///
 509 std::vector<unsigned> TGParser::ParseRangeList() {
 510   std::vector<unsigned> Result;
 511
 512   // Parse the first piece.
 513   if (ParseRangePiece(Result))
 514     return std::vector<unsigned>();
 515   while (Lex.getCode() == tgtok::comma) {
 516     Lex.Lex();  // Eat the comma.
 517
 518     // Parse the next range piece.
 519     if (ParseRangePiece(Result))
 520       return std::vector<unsigned>();
 521   }
 522   return Result;
 523 }
 524
 525 /// ParseOptionalRangeList - Parse either a range list in <>'s or nothing.
 526 ///   OptionalRangeList ::= '<' RangeList '>'
 527 ///   OptionalRangeList ::= /*empty*/
 528 bool TGParser::ParseOptionalRangeList(std::vector<unsigned> &Ranges) {
 529   if (Lex.getCode() != tgtok::less)
 530     return false;
 531
 532   SMLoc StartLoc = Lex.getLoc();
 533   Lex.Lex(); // eat the '<'
 534
 535   // Parse the range list.
 536   Ranges = ParseRangeList();
 537   if (Ranges.empty()) return true;
 538
 539   if (Lex.getCode() != tgtok::greater) {
 540     TokError("expected '>' at end of range list");
 541     return Error(StartLoc, "to match this '<'");
 542   }
 543   Lex.Lex();   // eat the '>'.
 544   return false;
 545 }
 546
 547 /// ParseOptionalBitList - Parse either a bit list in {}'s or nothing.
 548 ///   OptionalBitList ::= '{' RangeList '}'
 549 ///   OptionalBitList ::= /*empty*/
 550 bool TGParser::ParseOptionalBitList(std::vector<unsigned> &Ranges) {
 551   if (Lex.getCode() != tgtok::l_brace)
 552     return false;
 553
 554   SMLoc StartLoc = Lex.getLoc();
 555   Lex.Lex(); // eat the '{'
 556
 557   // Parse the range list.
 558   Ranges = ParseRangeList();
 559   if (Ranges.empty()) return true;
 560
 561   if (Lex.getCode() != tgtok::r_brace) {
 562     TokError("expected '}' at end of bit list");
 563     return Error(StartLoc, "to match this '{'");
 564   }
 565   Lex.Lex();   // eat the '}'.
 566   return false;
 567 }
 568
 569
 570 /// ParseType - Parse and return a tblgen type.  This returns null on error.
 571 ///
 572 ///   Type ::= STRING                       // string type
 573 ///   Type ::= BIT                          // bit type
 574 ///   Type ::= BITS '<' INTVAL '>'          // bits<x> type
 575 ///   Type ::= INT                          // int type
 576 ///   Type ::= LIST '<' Type '>'            // list<x> type
 577 ///   Type ::= CODE                         // code type
 578 ///   Type ::= DAG                          // dag type
 579 ///   Type ::= ClassID                      // Record Type
 580 ///
 581 RecTy *TGParser::ParseType() {
 582   switch (Lex.getCode()) {
 583   default: TokError("Unknown token when expecting a type"); return 0;
 584   case tgtok::String: Lex.Lex(); return new StringRecTy();
 585   case tgtok::Bit:    Lex.Lex(); return new BitRecTy();
 586   case tgtok::Int:    Lex.Lex(); return new IntRecTy();
 587   case tgtok::Code:   Lex.Lex(); return new CodeRecTy();
 588   case tgtok::Dag:    Lex.Lex(); return new DagRecTy();
 589   case tgtok::Id:
 590     if (Record *R = ParseClassID()) return new RecordRecTy(R);
 591     return 0;
 592   case tgtok::Bits: {
 593     if (Lex.Lex() != tgtok::less) { // Eat 'bits'
 594       TokError("expected '<' after bits type");
 595       return 0;
 596     }
 597     if (Lex.Lex() != tgtok::IntVal) {  // Eat '<'
 598       TokError("expected integer in bits<n> type");
 599       return 0;
 600     }
 601     uint64_t Val = Lex.getCurIntVal();
 602     if (Lex.Lex() != tgtok::greater) {  // Eat count.
 603       TokError("expected '>' at end of bits<n> type");
 604       return 0;
 605     }
 606     Lex.Lex();  // Eat '>'
 607     return new BitsRecTy(Val);
 608   }
 609   case tgtok::List: {
 610     if (Lex.Lex() != tgtok::less) { // Eat 'bits'
 611       TokError("expected '<' after list type");
 612       return 0;
 613     }
 614     Lex.Lex();  // Eat '<'
 615     RecTy *SubType = ParseType();
 616     if (SubType == 0) return 0;
 617
 618     if (Lex.getCode() != tgtok::greater) {
 619       TokError("expected '>' at end of list<ty> type");
 620       return 0;
 621     }
 622     Lex.Lex();  // Eat '>'
 623     return new ListRecTy(SubType);
 624   }
 625   }
 626 }
 627
 628 /// ParseIDValue - Parse an ID as a value and decode what it means.
 629 ///
 630 ///  IDValue ::= ID [def local value]
 631 ///  IDValue ::= ID [def template arg]
 632 ///  IDValue ::= ID [multiclass local value]
 633 ///  IDValue ::= ID [multiclass template argument]
 634 ///  IDValue ::= ID [def name]
 635 ///
 636 Init *TGParser::ParseIDValue(Record *CurRec) {
 637   assert(Lex.getCode() == tgtok::Id && "Expected ID in ParseIDValue");
 638   std::string Name = Lex.getCurStrVal();
 639   SMLoc Loc = Lex.getLoc();
 640   Lex.Lex();
 641   return ParseIDValue(CurRec, Name, Loc);
 642 }
 643
 644 /// ParseIDValue - This is just like ParseIDValue above, but it assumes the ID
 645 /// has already been read.
 646 Init *TGParser::ParseIDValue(Record *CurRec,
 647                              const std::string &Name, SMLoc NameLoc) {
 648   if (CurRec) {
 649     if (const RecordVal *RV = CurRec->getValue(Name))
 650       return new VarInit(Name, RV->getType());
 651
 652     std::string TemplateArgName = CurRec->getName()+":"+Name;
 653     if (CurRec->isTemplateArg(TemplateArgName)) {
 654       const RecordVal *RV = CurRec->getValue(TemplateArgName);
 655       assert(RV && "Template arg doesn't exist??");
 656       return new VarInit(TemplateArgName, RV->getType());
 657     }
 658   }
 659
 660   if (CurMultiClass) {
 661     std::string MCName = CurMultiClass->Rec.getName()+"::"+Name;
 662     if (CurMultiClass->Rec.isTemplateArg(MCName)) {
 663       const RecordVal *RV = CurMultiClass->Rec.getValue(MCName);
 664       assert(RV && "Template arg doesn't exist??");
 665       return new VarInit(MCName, RV->getType());
 666     }
 667   }
 668
 669   if (Record *D = Records.getDef(Name))
 670     return new DefInit(D);
 671
 672   Error(NameLoc, "Variable not defined: '" + Name + "'");
 673   return 0;
 674 }
 675
 676 /// ParseOperation - Parse an operator.  This returns null on error.
 677 ///
 678 /// Operation ::= XOperator ['<' Type '>'] '(' Args ')'
 679 ///
 680 Init *TGParser::ParseOperation(Record *CurRec) {
 681   switch (Lex.getCode()) {
 682   default:
 683     TokError("unknown operation");
 684     return 0;
 685     break;
 686   case tgtok::XHead:
 687   case tgtok::XTail:
 688   case tgtok::XEmpty:
 689   case tgtok::XCast: {  // Value ::= !unop '(' Value ')'
 690     UnOpInit::UnaryOp Code;
 691     RecTy *Type = 0;
 692
 693     switch (Lex.getCode()) {
 694     default: assert(0 && "Unhandled code!");
 695     case tgtok::XCast:
 696       Lex.Lex();  // eat the operation
 697       Code = UnOpInit::CAST;
 698
 699       Type = ParseOperatorType();
 700
 701       if (Type == 0) {
 702         TokError("did not get type for unary operator");
 703         return 0;
 704       }
 705
 706       break;
 707     case tgtok::XHead:
 708       Lex.Lex();  // eat the operation
 709       Code = UnOpInit::HEAD;
 710       break;
 711     case tgtok::XTail:
 712       Lex.Lex();  // eat the operation
 713       Code = UnOpInit::TAIL;
 714       break;
 715     case tgtok::XEmpty:
 716       Lex.Lex();  // eat the operation
 717       Code = UnOpInit::EMPTY;
 718       Type = new IntRecTy;
 719       break;
 720     }
 721     if (Lex.getCode() != tgtok::l_paren) {
 722       TokError("expected '(' after unary operator");
 723       return 0;
 724     }
 725     Lex.Lex();  // eat the '('
 726
 727     Init *LHS = ParseValue(CurRec);
 728     if (LHS == 0) return 0;
 729
 730     if (Code == UnOpInit::HEAD
 731         || Code == UnOpInit::TAIL
 732         || Code == UnOpInit::EMPTY) {
 733       ListInit *LHSl = dynamic_cast<ListInit*>(LHS);
 734       StringInit *LHSs = dynamic_cast<StringInit*>(LHS);
 735       TypedInit *LHSt = dynamic_cast<TypedInit*>(LHS);
 736       if (LHSl == 0 && LHSs == 0 && LHSt == 0) {
 737         TokError("expected list or string type argument in unary operator");
 738         return 0;
 739       }
 740       if (LHSt) {
 741         ListRecTy *LType = dynamic_cast<ListRecTy*>(LHSt->getType());
 742         StringRecTy *SType = dynamic_cast<StringRecTy*>(LHSt->getType());
 743         if (LType == 0 && SType == 0) {
 744           TokError("expected list or string type argumnet in unary operator");
 745           return 0;
 746         }
 747       }
 748
 749       if (Code == UnOpInit::HEAD
 750           || Code == UnOpInit::TAIL) {
 751         if (LHSl == 0 && LHSt == 0) {
 752           TokError("expected list type argumnet in unary operator");
 753           return 0;
 754         }
 755
 756         if (LHSl && LHSl->getSize() == 0) {
 757           TokError("empty list argument in unary operator");
 758           return 0;
 759         }
 760         if (LHSl) {
 761           Init *Item = LHSl->getElement(0);
 762           TypedInit *Itemt = dynamic_cast<TypedInit*>(Item);
 763           if (Itemt == 0) {
 764             TokError("untyped list element in unary operator");
 765             return 0;
 766           }
 767           if (Code == UnOpInit::HEAD) {
 768             Type = Itemt->getType();
 769           } else {
 770             Type = new ListRecTy(Itemt->getType());
 771           }
 772         } else {
 773           assert(LHSt && "expected list type argument in unary operator");
 774           ListRecTy *LType = dynamic_cast<ListRecTy*>(LHSt->getType());
 775           if (LType == 0) {
 776             TokError("expected list type argumnet in unary operator");
 777             return 0;
 778           }
 779           if (Code == UnOpInit::HEAD) {
 780             Type = LType->getElementType();
 781           } else {
 782             Type = LType;
 783           }
 784         }
 785       }
 786     }
 787
 788     if (Lex.getCode() != tgtok::r_paren) {
 789       TokError("expected ')' in unary operator");
 790       return 0;
 791     }
 792     Lex.Lex();  // eat the ')'
 793     return (new UnOpInit(Code, LHS, Type))->Fold(CurRec, CurMultiClass);
 794   }
 795
 796   case tgtok::XConcat:
 797   case tgtok::XSRA:
 798   case tgtok::XSRL:
 799   case tgtok::XSHL:
 800   case tgtok::XEq:
 801   case tgtok::XStrConcat: {  // Value ::= !binop '(' Value ',' Value ')'
 802     tgtok::TokKind OpTok = Lex.getCode();
 803     SMLoc OpLoc = Lex.getLoc();
 804     Lex.Lex();  // eat the operation
 805
 806     BinOpInit::BinaryOp Code;
 807     RecTy *Type = 0;
 808
 809     switch (OpTok) {
 810     default: assert(0 && "Unhandled code!");
 811     case tgtok::XConcat: Code = BinOpInit::CONCAT; Type = new DagRecTy(); break;
 812     case tgtok::XSRA:    Code = BinOpInit::SRA;    Type = new IntRecTy(); break;
 813     case tgtok::XSRL:    Code = BinOpInit::SRL;    Type = new IntRecTy(); break;
 814     case tgtok::XSHL:    Code = BinOpInit::SHL;    Type = new IntRecTy(); break;
 815     case tgtok::XEq:     Code = BinOpInit::EQ;     Type = new BitRecTy(); break;
 816     case tgtok::XStrConcat:
 817       Code = BinOpInit::STRCONCAT;
 818       Type = new StringRecTy();
 819       break;
 820     }
 821
 822     if (Lex.getCode() != tgtok::l_paren) {
 823       TokError("expected '(' after binary operator");
 824       return 0;
 825     }
 826     Lex.Lex();  // eat the '('
 827
 828     SmallVector<Init*, 2> InitList;
 829
 830     InitList.push_back(ParseValue(CurRec));
 831     if (InitList.back() == 0) return 0;
 832
 833     while (Lex.getCode() == tgtok::comma) {
 834       Lex.Lex();  // eat the ','
 835
 836       InitList.push_back(ParseValue(CurRec));
 837       if (InitList.back() == 0) return 0;
 838     }
 839
 840     if (Lex.getCode() != tgtok::r_paren) {
 841       TokError("expected ')' in operator");
 842       return 0;
 843     }
 844     Lex.Lex();  // eat the ')'
 845
 846     // We allow multiple operands to associative operators like !strconcat as
 847     // shorthand for nesting them.
 848     if (Code == BinOpInit::STRCONCAT) {
 849       while (InitList.size() > 2) {
 850         Init *RHS = InitList.pop_back_val();
 851         RHS = (new BinOpInit(Code, InitList.back(), RHS, Type))
 852                       ->Fold(CurRec, CurMultiClass);
 853         InitList.back() = RHS;
 854       }
 855     }
 856
 857     if (InitList.size() == 2)
 858       return (new BinOpInit(Code, InitList[0], InitList[1], Type))
 859         ->Fold(CurRec, CurMultiClass);
 860
 861     Error(OpLoc, "expected two operands to operator");
 862     return 0;
 863   }
 864
 865   case tgtok::XIf:
 866   case tgtok::XForEach:
 867   case tgtok::XSubst: {  // Value ::= !ternop '(' Value ',' Value ',' Value ')'
 868     TernOpInit::TernaryOp Code;
 869     RecTy *Type = 0;
 870
 871     tgtok::TokKind LexCode = Lex.getCode();
 872     Lex.Lex();  // eat the operation
 873     switch (LexCode) {
 874     default: assert(0 && "Unhandled code!");
 875     case tgtok::XIf:
 876       Code = TernOpInit::IF;
 877       break;
 878     case tgtok::XForEach:
 879       Code = TernOpInit::FOREACH;
 880       break;
 881     case tgtok::XSubst:
 882       Code = TernOpInit::SUBST;
 883       break;
 884     }
 885     if (Lex.getCode() != tgtok::l_paren) {
 886       TokError("expected '(' after ternary operator");
 887       return 0;
 888     }
 889     Lex.Lex();  // eat the '('
 890
 891     Init *LHS = ParseValue(CurRec);
 892     if (LHS == 0) return 0;
 893
 894     if (Lex.getCode() != tgtok::comma) {
 895       TokError("expected ',' in ternary operator");
 896       return 0;
 897     }
 898     Lex.Lex();  // eat the ','
 899
 900     Init *MHS = ParseValue(CurRec);
 901     if (MHS == 0) return 0;
 902
 903     if (Lex.getCode() != tgtok::comma) {
 904       TokError("expected ',' in ternary operator");
 905       return 0;
 906     }
 907     Lex.Lex();  // eat the ','
 908
 909     Init *RHS = ParseValue(CurRec);
 910     if (RHS == 0) return 0;
 911
 912     if (Lex.getCode() != tgtok::r_paren) {
 913       TokError("expected ')' in binary operator");
 914       return 0;
 915     }
 916     Lex.Lex();  // eat the ')'
 917
 918     switch (LexCode) {
 919     default: assert(0 && "Unhandled code!");
 920     case tgtok::XIf: {
 921       // FIXME: The `!if' operator doesn't handle non-TypedInit well at
 922       // all. This can be made much more robust.
 923       TypedInit *MHSt = dynamic_cast<TypedInit*>(MHS);
 924       TypedInit *RHSt = dynamic_cast<TypedInit*>(RHS);
 925
 926       RecTy *MHSTy = 0;
 927       RecTy *RHSTy = 0;
 928
 929       if (MHSt == 0 && RHSt == 0) {
 930         BitsInit *MHSbits = dynamic_cast<BitsInit*>(MHS);
 931         BitsInit *RHSbits = dynamic_cast<BitsInit*>(RHS);
 932
 933         if (MHSbits && RHSbits &&
 934             MHSbits->getNumBits() == RHSbits->getNumBits()) {
 935           Type = new BitRecTy();
 936           break;
 937         } else {
 938           BitInit *MHSbit = dynamic_cast<BitInit*>(MHS);
 939           BitInit *RHSbit = dynamic_cast<BitInit*>(RHS);
 940
 941           if (MHSbit && RHSbit) {
 942             Type = new BitRecTy();
 943             break;
 944           }
 945         }
 946       } else if (MHSt != 0 && RHSt != 0) {
 947         MHSTy = MHSt->getType();
 948         RHSTy = RHSt->getType();
 949       }
 950
 951       if (!MHSTy || !RHSTy) {
 952         TokError("could not get type for !if");
 953         return 0;
 954       }
 955
 956       if (MHSTy->typeIsConvertibleTo(RHSTy)) {
 957         Type = RHSTy;
 958       } else if (RHSTy->typeIsConvertibleTo(MHSTy)) {
 959         Type = MHSTy;
 960       } else {
 961         TokError("inconsistent types for !if");
 962         return 0;
 963       }
 964       break;
 965     }
 966     case tgtok::XForEach: {
 967       TypedInit *MHSt = dynamic_cast<TypedInit *>(MHS);
 968       if (MHSt == 0) {
 969         TokError("could not get type for !foreach");
 970         return 0;
 971       }
 972       Type = MHSt->getType();
 973       break;
 974     }
 975     case tgtok::XSubst: {
 976       TypedInit *RHSt = dynamic_cast<TypedInit *>(RHS);
 977       if (RHSt == 0) {
 978         TokError("could not get type for !subst");
 979         return 0;
 980       }
 981       Type = RHSt->getType();
 982       break;
 983     }
 984     }
 985     return (new TernOpInit(Code, LHS, MHS, RHS, Type))->Fold(CurRec,
 986                                                              CurMultiClass);
 987   }
 988   }
 989   TokError("could not parse operation");
 990   return 0;
 991 }
 992
 993 /// ParseOperatorType - Parse a type for an operator.  This returns
 994 /// null on error.
 995 ///
 996 /// OperatorType ::= '<' Type '>'
 997 ///
 998 RecTy *TGParser::ParseOperatorType() {
 999   RecTy *Type = 0;
1000
1001   if (Lex.getCode() != tgtok::less) {
1002     TokError("expected type name for operator");
1003     return 0;
1004   }
1005   Lex.Lex();  // eat the <
1006
1007   Type = ParseType();
1008
1009   if (Type == 0) {
1010     TokError("expected type name for operator");
1011     return 0;
1012   }
1013
1014   if (Lex.getCode() != tgtok::greater) {
1015     TokError("expected type name for operator");
1016     return 0;
1017   }
1018   Lex.Lex();  // eat the >
1019
1020   return Type;
1021 }
1022
1023
1024 /// ParseSimpleValue - Parse a tblgen value.  This returns null on error.
1025 ///
1026 ///   SimpleValue ::= IDValue
1027 ///   SimpleValue ::= INTVAL
1028 ///   SimpleValue ::= STRVAL+
1029 ///   SimpleValue ::= CODEFRAGMENT
1030 ///   SimpleValue ::= '?'
1031 ///   SimpleValue ::= '{' ValueList '}'
1032 ///   SimpleValue ::= ID '<' ValueListNE '>'
1033 ///   SimpleValue ::= '[' ValueList ']'
1034 ///   SimpleValue ::= '(' IDValue DagArgList ')'
1035 ///   SimpleValue ::= CONCATTOK '(' Value ',' Value ')'
1036 ///   SimpleValue ::= SHLTOK '(' Value ',' Value ')'
1037 ///   SimpleValue ::= SRATOK '(' Value ',' Value ')'
1038 ///   SimpleValue ::= SRLTOK '(' Value ',' Value ')'
1039 ///   SimpleValue ::= STRCONCATTOK '(' Value ',' Value ')'
1040 ///
1041 Init *TGParser::ParseSimpleValue(Record *CurRec, RecTy *ItemType) {
1042   Init *R = 0;
1043   switch (Lex.getCode()) {
1044   default: TokError("Unknown token when parsing a value"); break;
1045   case tgtok::IntVal: R = new IntInit(Lex.getCurIntVal()); Lex.Lex(); break;
1046   case tgtok::StrVal: {
1047     std::string Val = Lex.getCurStrVal();
1048     Lex.Lex();
1049
1050     // Handle multiple consecutive concatenated strings.
1051     while (Lex.getCode() == tgtok::StrVal) {
1052       Val += Lex.getCurStrVal();
1053       Lex.Lex();
1054     }
1055
1056     R = new StringInit(Val);
1057     break;
1058   }
1059   case tgtok::CodeFragment:
1060     R = new CodeInit(Lex.getCurStrVal());
1061     Lex.Lex();
1062     break;
1063   case tgtok::question:
1064     R = new UnsetInit();
1065     Lex.Lex();
1066     break;
1067   case tgtok::Id: {
1068     SMLoc NameLoc = Lex.getLoc();
1069     std::string Name = Lex.getCurStrVal();
1070     if (Lex.Lex() != tgtok::less)  // consume the Id.
1071       return ParseIDValue(CurRec, Name, NameLoc);    // Value ::= IDValue
1072
1073     // Value ::= ID '<' ValueListNE '>'
1074     if (Lex.Lex() == tgtok::greater) {
1075       TokError("expected non-empty value list");
1076       return 0;
1077     }
1078
1079     // This is a CLASS<initvalslist> expression.  This is supposed to synthesize
1080     // a new anonymous definition, deriving from CLASS<initvalslist> with no
1081     // body.
1082     Record *Class = Records.getClass(Name);
1083     if (!Class) {
1084       Error(NameLoc, "Expected a class name, got '" + Name + "'");
1085       return 0;
1086     }
1087
1088     std::vector<Init*> ValueList = ParseValueList(CurRec, Class);
1089     if (ValueList.empty()) return 0;
1090
1091     if (Lex.getCode() != tgtok::greater) {
1092       TokError("expected '>' at end of value list");
1093       return 0;
1094     }
1095     Lex.Lex();  // eat the '>'
1096
1097     // Create the new record, set it as CurRec temporarily.
1098     static unsigned AnonCounter = 0;
1099     Record *NewRec = new Record("anonymous.val."+utostr(AnonCounter++),
1100                                 NameLoc,
1101                                 Records);
1102     SubClassReference SCRef;
1103     SCRef.RefLoc = NameLoc;
1104     SCRef.Rec = Class;
1105     SCRef.TemplateArgs = ValueList;
1106     // Add info about the subclass to NewRec.
1107     if (AddSubClass(NewRec, SCRef))
1108       return 0;
1109     NewRec->resolveReferences();
1110     Records.addDef(NewRec);
1111
1112     // The result of the expression is a reference to the new record.
1113     return new DefInit(NewRec);
1114   }
1115   case tgtok::l_brace: {           // Value ::= '{' ValueList '}'
1116     SMLoc BraceLoc = Lex.getLoc();
1117     Lex.Lex(); // eat the '{'
1118     std::vector<Init*> Vals;
1119
1120     if (Lex.getCode() != tgtok::r_brace) {
1121       Vals = ParseValueList(CurRec);
1122       if (Vals.empty()) return 0;
1123     }
1124     if (Lex.getCode() != tgtok::r_brace) {
1125       TokError("expected '}' at end of bit list value");
1126       return 0;
1127     }
1128     Lex.Lex();  // eat the '}'
1129
1130     BitsInit *Result = new BitsInit(Vals.size());
1131     for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1132       Init *Bit = Vals[i]->convertInitializerTo(new BitRecTy());
1133       if (Bit == 0) {
1134         Error(BraceLoc, "Element #" + utostr(i) + " (" + Vals[i]->getAsString()+
1135               ") is not convertable to a bit");
1136         return 0;
1137       }
1138       Result->setBit(Vals.size()-i-1, Bit);
1139     }
1140     return Result;
1141   }
1142   case tgtok::l_square: {          // Value ::= '[' ValueList ']'
1143     Lex.Lex(); // eat the '['
1144     std::vector<Init*> Vals;
1145
1146     RecTy *DeducedEltTy = 0;
1147     ListRecTy *GivenListTy = 0;
1148
1149     if (ItemType != 0) {
1150       ListRecTy *ListType = dynamic_cast<ListRecTy*>(ItemType);
1151       if (ListType == 0) {
1152         std::stringstream s;
1153         s << "Type mismatch for list, expected list type, got "
1154           << ItemType->getAsString();
1155         TokError(s.str());
1156         return 0;
1157       }
1158       GivenListTy = ListType;
1159     }
1160
1161     if (Lex.getCode() != tgtok::r_square) {
1162       Vals = ParseValueList(CurRec, 0,
1163                             GivenListTy ? GivenListTy->getElementType() : 0);
1164       if (Vals.empty()) return 0;
1165     }
1166     if (Lex.getCode() != tgtok::r_square) {
1167       TokError("expected ']' at end of list value");
1168       return 0;
1169     }
1170     Lex.Lex();  // eat the ']'
1171
1172     RecTy *GivenEltTy = 0;
1173     if (Lex.getCode() == tgtok::less) {
1174       // Optional list element type
1175       Lex.Lex();  // eat the '<'
1176
1177       GivenEltTy = ParseType();
1178       if (GivenEltTy == 0) {
1179         // Couldn't parse element type
1180         return 0;
1181       }
1182
1183       if (Lex.getCode() != tgtok::greater) {
1184         TokError("expected '>' at end of list element type");
1185         return 0;
1186       }
1187       Lex.Lex();  // eat the '>'
1188     }
1189
1190     // Check elements
1191     RecTy *EltTy = 0;
1192     for (std::vector<Init *>::iterator i = Vals.begin(), ie = Vals.end();
1193          i != ie;
1194          ++i) {
1195       TypedInit *TArg = dynamic_cast<TypedInit*>(*i);
1196       if (TArg == 0) {
1197         TokError("Untyped list element");
1198         return 0;
1199       }
1200       if (EltTy != 0) {
1201         EltTy = resolveTypes(EltTy, TArg->getType());
1202         if (EltTy == 0) {
1203           TokError("Incompatible types in list elements");
1204           return 0;
1205         }
1206       } else {
1207         EltTy = TArg->getType();
1208       }
1209     }
1210
1211     if (GivenEltTy != 0) {
1212       if (EltTy != 0) {
1213         // Verify consistency
1214         if (!EltTy->typeIsConvertibleTo(GivenEltTy)) {
1215           TokError("Incompatible types in list elements");
1216           return 0;
1217         }
1218       }
1219       EltTy = GivenEltTy;
1220     }
1221
1222     if (EltTy == 0) {
1223       if (ItemType == 0) {
1224         TokError("No type for list");
1225         return 0;
1226       }
1227       DeducedEltTy = GivenListTy->getElementType();
1228     } else {
1229       // Make sure the deduced type is compatible with the given type
1230       if (GivenListTy) {
1231         if (!EltTy->typeIsConvertibleTo(GivenListTy->getElementType())) {
1232           TokError("Element type mismatch for list");
1233           return 0;
1234         }
1235       }
1236       DeducedEltTy = EltTy;
1237     }
1238
1239     return new ListInit(Vals, DeducedEltTy);
1240   }
1241   case tgtok::l_paren: {         // Value ::= '(' IDValue DagArgList ')'
1242     Lex.Lex();   // eat the '('
1243     if (Lex.getCode() != tgtok::Id && Lex.getCode() != tgtok::XCast) {
1244       TokError("expected identifier in dag init");
1245       return 0;
1246     }
1247
1248     Init *Operator = ParseValue(CurRec);
1249     if (Operator == 0) return 0;
1250
1251     // If the operator name is present, parse it.
1252     std::string OperatorName;
1253     if (Lex.getCode() == tgtok::colon) {
1254       if (Lex.Lex() != tgtok::VarName) { // eat the ':'
1255         TokError("expected variable name in dag operator");
1256         return 0;
1257       }
1258       OperatorName = Lex.getCurStrVal();
1259       Lex.Lex();  // eat the VarName.
1260     }
1261
1262     std::vector<std::pair<llvm::Init*, std::string> > DagArgs;
1263     if (Lex.getCode() != tgtok::r_paren) {
1264       DagArgs = ParseDagArgList(CurRec);
1265       if (DagArgs.empty()) return 0;
1266     }
1267
1268     if (Lex.getCode() != tgtok::r_paren) {
1269       TokError("expected ')' in dag init");
1270       return 0;
1271     }
1272     Lex.Lex();  // eat the ')'
1273
1274     return new DagInit(Operator, OperatorName, DagArgs);
1275   }
1276
1277   case tgtok::XHead:
1278   case tgtok::XTail:
1279   case tgtok::XEmpty:
1280   case tgtok::XCast:  // Value ::= !unop '(' Value ')'
1281   case tgtok::XConcat:
1282   case tgtok::XSRA:
1283   case tgtok::XSRL:
1284   case tgtok::XSHL:
1285   case tgtok::XEq:
1286   case tgtok::XStrConcat:   // Value ::= !binop '(' Value ',' Value ')'
1287   case tgtok::XIf:
1288   case tgtok::XForEach:
1289   case tgtok::XSubst: {  // Value ::= !ternop '(' Value ',' Value ',' Value ')'
1290     return ParseOperation(CurRec);
1291   }
1292   }
1293
1294   return R;
1295 }
1296
1297 /// ParseValue - Parse a tblgen value.  This returns null on error.
1298 ///
1299 ///   Value       ::= SimpleValue ValueSuffix*
1300 ///   ValueSuffix ::= '{' BitList '}'
1301 ///   ValueSuffix ::= '[' BitList ']'
1302 ///   ValueSuffix ::= '.' ID
1303 ///
1304 Init *TGParser::ParseValue(Record *CurRec, RecTy *ItemType) {
1305   Init *Result = ParseSimpleValue(CurRec, ItemType);
1306   if (Result == 0) return 0;
1307
1308   // Parse the suffixes now if present.
1309   while (1) {
1310     switch (Lex.getCode()) {
1311     default: return Result;
1312     case tgtok::l_brace: {
1313       SMLoc CurlyLoc = Lex.getLoc();
1314       Lex.Lex(); // eat the '{'
1315       std::vector<unsigned> Ranges = ParseRangeList();
1316       if (Ranges.empty()) return 0;
1317
1318       // Reverse the bitlist.
1319       std::reverse(Ranges.begin(), Ranges.end());
1320       Result = Result->convertInitializerBitRange(Ranges);
1321       if (Result == 0) {
1322         Error(CurlyLoc, "Invalid bit range for value");
1323         return 0;
1324       }
1325
1326       // Eat the '}'.
1327       if (Lex.getCode() != tgtok::r_brace) {
1328         TokError("expected '}' at end of bit range list");
1329         return 0;
1330       }
1331       Lex.Lex();
1332       break;
1333     }
1334     case tgtok::l_square: {
1335       SMLoc SquareLoc = Lex.getLoc();
1336       Lex.Lex(); // eat the '['
1337       std::vector<unsigned> Ranges = ParseRangeList();
1338       if (Ranges.empty()) return 0;
1339
1340       Result = Result->convertInitListSlice(Ranges);
1341       if (Result == 0) {
1342         Error(SquareLoc, "Invalid range for list slice");
1343         return 0;
1344       }
1345
1346       // Eat the ']'.
1347       if (Lex.getCode() != tgtok::r_square) {
1348         TokError("expected ']' at end of list slice");
1349         return 0;
1350       }
1351       Lex.Lex();
1352       break;
1353     }
1354     case tgtok::period:
1355       if (Lex.Lex() != tgtok::Id) {  // eat the .
1356         TokError("expected field identifier after '.'");
1357         return 0;
1358       }
1359       if (!Result->getFieldType(Lex.getCurStrVal())) {
1360         TokError("Cannot access field '" + Lex.getCurStrVal() + "' of value '" +
1361                  Result->getAsString() + "'");
1362         return 0;
1363       }
1364       Result = new FieldInit(Result, Lex.getCurStrVal());
1365       Lex.Lex();  // eat field name
1366       break;
1367     }
1368   }
1369 }
1370
1371 /// ParseDagArgList - Parse the argument list for a dag literal expression.
1372 ///
1373 ///    ParseDagArgList ::= Value (':' VARNAME)?
1374 ///    ParseDagArgList ::= ParseDagArgList ',' Value (':' VARNAME)?
1375 std::vector<std::pair<llvm::Init*, std::string> >
1376 TGParser::ParseDagArgList(Record *CurRec) {
1377   std::vector<std::pair<llvm::Init*, std::string> > Result;
1378
1379   while (1) {
1380     Init *Val = ParseValue(CurRec);
1381     if (Val == 0) return std::vector<std::pair<llvm::Init*, std::string> >();
1382
1383     // If the variable name is present, add it.
1384     std::string VarName;
1385     if (Lex.getCode() == tgtok::colon) {
1386       if (Lex.Lex() != tgtok::VarName) { // eat the ':'
1387         TokError("expected variable name in dag literal");
1388         return std::vector<std::pair<llvm::Init*, std::string> >();
1389       }
1390       VarName = Lex.getCurStrVal();
1391       Lex.Lex();  // eat the VarName.
1392     }
1393
1394     Result.push_back(std::make_pair(Val, VarName));
1395
1396     if (Lex.getCode() != tgtok::comma) break;
1397     Lex.Lex(); // eat the ','
1398   }
1399
1400   return Result;
1401 }
1402
1403
1404 /// ParseValueList - Parse a comma separated list of values, returning them as a
1405 /// vector.  Note that this always expects to be able to parse at least one
1406 /// value.  It returns an empty list if this is not possible.
1407 ///
1408 ///   ValueList ::= Value (',' Value)
1409 ///
1410 std::vector<Init*> TGParser::ParseValueList(Record *CurRec, Record *ArgsRec,
1411                                             RecTy *EltTy) {
1412   std::vector<Init*> Result;
1413   RecTy *ItemType = EltTy;
1414   unsigned int ArgN = 0;
1415   if (ArgsRec != 0 && EltTy == 0) {
1416     const std::vector<std::string> &TArgs = ArgsRec->getTemplateArgs();
1417     const RecordVal *RV = ArgsRec->getValue(TArgs[ArgN]);
1418     assert(RV && "Template argument record not found??");
1419     ItemType = RV->getType();
1420     ++ArgN;
1421   }
1422   Result.push_back(ParseValue(CurRec, ItemType));
1423   if (Result.back() == 0) return std::vector<Init*>();
1424
1425   while (Lex.getCode() == tgtok::comma) {
1426     Lex.Lex();  // Eat the comma
1427
1428     if (ArgsRec != 0 && EltTy == 0) {
1429       const std::vector<std::string> &TArgs = ArgsRec->getTemplateArgs();
1430       if (ArgN >= TArgs.size()) {
1431         TokError("too many template arguments");
1432         return std::vector<Init*>();
1433       }
1434       const RecordVal *RV = ArgsRec->getValue(TArgs[ArgN]);
1435       assert(RV && "Template argument record not found??");
1436       ItemType = RV->getType();
1437       ++ArgN;
1438     }
1439     Result.push_back(ParseValue(CurRec, ItemType));
1440     if (Result.back() == 0) return std::vector<Init*>();
1441   }
1442
1443   return Result;
1444 }
1445
1446
1447 /// ParseDeclaration - Read a declaration, returning the name of field ID, or an
1448 /// empty string on error.  This can happen in a number of different context's,
1449 /// including within a def or in the template args for a def (which which case
1450 /// CurRec will be non-null) and within the template args for a multiclass (in
1451 /// which case CurRec will be null, but CurMultiClass will be set).  This can
1452 /// also happen within a def that is within a multiclass, which will set both
1453 /// CurRec and CurMultiClass.
1454 ///
1455 ///  Declaration ::= FIELD? Type ID ('=' Value)?
1456 ///
1457 std::string TGParser::ParseDeclaration(Record *CurRec,
1458                                        bool ParsingTemplateArgs) {
1459   // Read the field prefix if present.
1460   bool HasField = Lex.getCode() == tgtok::Field;
1461   if (HasField) Lex.Lex();
1462
1463   RecTy *Type = ParseType();
1464   if (Type == 0) return "";
1465
1466   if (Lex.getCode() != tgtok::Id) {
1467     TokError("Expected identifier in declaration");
1468     return "";
1469   }
1470
1471   SMLoc IdLoc = Lex.getLoc();
1472   std::string DeclName = Lex.getCurStrVal();
1473   Lex.Lex();
1474
1475   if (ParsingTemplateArgs) {
1476     if (CurRec) {
1477       DeclName = CurRec->getName() + ":" + DeclName;
1478     } else {
1479       assert(CurMultiClass);
1480     }
1481     if (CurMultiClass)
1482       DeclName = CurMultiClass->Rec.getName() + "::" + DeclName;
1483   }
1484
1485   // Add the value.
1486   if (AddValue(CurRec, IdLoc, RecordVal(DeclName, Type, HasField)))
1487     return "";
1488
1489   // If a value is present, parse it.
1490   if (Lex.getCode() == tgtok::equal) {
1491     Lex.Lex();
1492     SMLoc ValLoc = Lex.getLoc();
1493     Init *Val = ParseValue(CurRec, Type);
1494     if (Val == 0 ||
1495         SetValue(CurRec, ValLoc, DeclName, std::vector<unsigned>(), Val))
1496       return "";
1497   }
1498
1499   return DeclName;
1500 }
1501
1502 /// ParseTemplateArgList - Read a template argument list, which is a non-empty
1503 /// sequence of template-declarations in <>'s.  If CurRec is non-null, these are
1504 /// template args for a def, which may or may not be in a multiclass.  If null,
1505 /// these are the template args for a multiclass.
1506 ///
1507 ///    TemplateArgList ::= '<' Declaration (',' Declaration)* '>'
1508 ///
1509 bool TGParser::ParseTemplateArgList(Record *CurRec) {
1510   assert(Lex.getCode() == tgtok::less && "Not a template arg list!");
1511   Lex.Lex(); // eat the '<'
1512
1513   Record *TheRecToAddTo = CurRec ? CurRec : &CurMultiClass->Rec;
1514
1515   // Read the first declaration.
1516   std::string TemplArg = ParseDeclaration(CurRec, true/*templateargs*/);
1517   if (TemplArg.empty())
1518     return true;
1519
1520   TheRecToAddTo->addTemplateArg(TemplArg);
1521
1522   while (Lex.getCode() == tgtok::comma) {
1523     Lex.Lex(); // eat the ','
1524
1525     // Read the following declarations.
1526     TemplArg = ParseDeclaration(CurRec, true/*templateargs*/);
1527     if (TemplArg.empty())
1528       return true;
1529     TheRecToAddTo->addTemplateArg(TemplArg);
1530   }
1531
1532   if (Lex.getCode() != tgtok::greater)
1533     return TokError("expected '>' at end of template argument list");
1534   Lex.Lex(); // eat the '>'.
1535   return false;
1536 }
1537
1538
1539 /// ParseBodyItem - Parse a single item at within the body of a def or class.
1540 ///
1541 ///   BodyItem ::= Declaration ';'
1542 ///   BodyItem ::= LET ID OptionalBitList '=' Value ';'
1543 bool TGParser::ParseBodyItem(Record *CurRec) {
1544   if (Lex.getCode() != tgtok::Let) {
1545     if (ParseDeclaration(CurRec, false).empty())
1546       return true;
1547
1548     if (Lex.getCode() != tgtok::semi)
1549       return TokError("expected ';' after declaration");
1550     Lex.Lex();
1551     return false;
1552   }
1553
1554   // LET ID OptionalRangeList '=' Value ';'
1555   if (Lex.Lex() != tgtok::Id)
1556     return TokError("expected field identifier after let");
1557
1558   SMLoc IdLoc = Lex.getLoc();
1559   std::string FieldName = Lex.getCurStrVal();
1560   Lex.Lex();  // eat the field name.
1561
1562   std::vector<unsigned> BitList;
1563   if (ParseOptionalBitList(BitList))
1564     return true;
1565   std::reverse(BitList.begin(), BitList.end());
1566
1567   if (Lex.getCode() != tgtok::equal)
1568     return TokError("expected '=' in let expression");
1569   Lex.Lex();  // eat the '='.
1570
1571   RecordVal *Field = CurRec->getValue(FieldName);
1572   if (Field == 0)
1573     return TokError("Value '" + FieldName + "' unknown!");
1574
1575   RecTy *Type = Field->getType();
1576
1577   Init *Val = ParseValue(CurRec, Type);
1578   if (Val == 0) return true;
1579
1580   if (Lex.getCode() != tgtok::semi)
1581     return TokError("expected ';' after let expression");
1582   Lex.Lex();
1583
1584   return SetValue(CurRec, IdLoc, FieldName, BitList, Val);
1585 }
1586
1587 /// ParseBody - Read the body of a class or def.  Return true on error, false on
1588 /// success.
1589 ///
1590 ///   Body     ::= ';'
1591 ///   Body     ::= '{' BodyList '}'
1592 ///   BodyList BodyItem*
1593 ///
1594 bool TGParser::ParseBody(Record *CurRec) {
1595   // If this is a null definition, just eat the semi and return.
1596   if (Lex.getCode() == tgtok::semi) {
1597     Lex.Lex();
1598     return false;
1599   }
1600
1601   if (Lex.getCode() != tgtok::l_brace)
1602     return TokError("Expected ';' or '{' to start body");
1603   // Eat the '{'.
1604   Lex.Lex();
1605
1606   while (Lex.getCode() != tgtok::r_brace)
1607     if (ParseBodyItem(CurRec))
1608       return true;
1609
1610   // Eat the '}'.
1611   Lex.Lex();
1612   return false;
1613 }
1614
1615 /// ParseObjectBody - Parse the body of a def or class.  This consists of an
1616 /// optional ClassList followed by a Body.  CurRec is the current def or class
1617 /// that is being parsed.
1618 ///
1619 ///   ObjectBody      ::= BaseClassList Body
1620 ///   BaseClassList   ::= /*empty*/
1621 ///   BaseClassList   ::= ':' BaseClassListNE
1622 ///   BaseClassListNE ::= SubClassRef (',' SubClassRef)*
1623 ///
1624 bool TGParser::ParseObjectBody(Record *CurRec) {
1625   // If there is a baseclass list, read it.
1626   if (Lex.getCode() == tgtok::colon) {
1627     Lex.Lex();
1628
1629     // Read all of the subclasses.
1630     SubClassReference SubClass = ParseSubClassReference(CurRec, false);
1631     while (1) {
1632       // Check for error.
1633       if (SubClass.Rec == 0) return true;
1634
1635       // Add it.
1636       if (AddSubClass(CurRec, SubClass))
1637         return true;
1638
1639       if (Lex.getCode() != tgtok::comma) break;
1640       Lex.Lex(); // eat ','.
1641       SubClass = ParseSubClassReference(CurRec, false);
1642     }
1643   }
1644
1645   // Process any variables on the let stack.
1646   for (unsigned i = 0, e = LetStack.size(); i != e; ++i)
1647     for (unsigned j = 0, e = LetStack[i].size(); j != e; ++j)
1648       if (SetValue(CurRec, LetStack[i][j].Loc, LetStack[i][j].Name,
1649                    LetStack[i][j].Bits, LetStack[i][j].Value))
1650         return true;
1651
1652   return ParseBody(CurRec);
1653 }
1654
1655 /// ParseDef - Parse and return a top level or multiclass def, return the record
1656 /// corresponding to it.  This returns null on error.
1657 ///
1658 ///   DefInst ::= DEF ObjectName ObjectBody
1659 ///
1660 bool TGParser::ParseDef(MultiClass *CurMultiClass) {
1661   SMLoc DefLoc = Lex.getLoc();
1662   assert(Lex.getCode() == tgtok::Def && "Unknown tok");
1663   Lex.Lex();  // Eat the 'def' token.
1664
1665   // Parse ObjectName and make a record for it.
1666   Record *CurRec = new Record(ParseObjectName(), DefLoc, Records);
1667
1668   if (!CurMultiClass) {
1669     // Top-level def definition.
1670
1671     // Ensure redefinition doesn't happen.
1672     if (Records.getDef(CurRec->getName())) {
1673       Error(DefLoc, "def '" + CurRec->getName() + "' already defined");
1674       return true;
1675     }
1676     Records.addDef(CurRec);
1677   } else {
1678     // Otherwise, a def inside a multiclass, add it to the multiclass.
1679     for (unsigned i = 0, e = CurMultiClass->DefPrototypes.size(); i != e; ++i)
1680       if (CurMultiClass->DefPrototypes[i]->getName() == CurRec->getName()) {
1681         Error(DefLoc, "def '" + CurRec->getName() +
1682               "' already defined in this multiclass!");
1683         return true;
1684       }
1685     CurMultiClass->DefPrototypes.push_back(CurRec);
1686   }
1687
1688   if (ParseObjectBody(CurRec))
1689     return true;
1690
1691   if (CurMultiClass == 0)  // Def's in multiclasses aren't really defs.
1692     CurRec->resolveReferences();
1693
1694   // If ObjectBody has template arguments, it's an error.
1695   assert(CurRec->getTemplateArgs().empty() && "How'd this get template args?");
1696
1697   if (CurMultiClass) {
1698     // Copy the template arguments for the multiclass into the def.
1699     const std::vector<std::string> &TArgs =
1700                                 CurMultiClass->Rec.getTemplateArgs();
1701
1702     for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
1703       const RecordVal *RV = CurMultiClass->Rec.getValue(TArgs[i]);
1704       assert(RV && "Template arg doesn't exist?");
1705       CurRec->addValue(*RV);
1706     }
1707   }
1708
1709   return false;
1710 }
1711
1712
1713 /// ParseClass - Parse a tblgen class definition.
1714 ///
1715 ///   ClassInst ::= CLASS ID TemplateArgList? ObjectBody
1716 ///
1717 bool TGParser::ParseClass() {
1718   assert(Lex.getCode() == tgtok::Class && "Unexpected token!");
1719   Lex.Lex();
1720
1721   if (Lex.getCode() != tgtok::Id)
1722     return TokError("expected class name after 'class' keyword");
1723
1724   Record *CurRec = Records.getClass(Lex.getCurStrVal());
1725   if (CurRec) {
1726     // If the body was previously defined, this is an error.
1727     if (!CurRec->getValues().empty() ||
1728         !CurRec->getSuperClasses().empty() ||
1729         !CurRec->getTemplateArgs().empty())
1730       return TokError("Class '" + CurRec->getName() + "' already defined");
1731   } else {
1732     // If this is the first reference to this class, create and add it.
1733     CurRec = new Record(Lex.getCurStrVal(), Lex.getLoc(), Records);
1734     Records.addClass(CurRec);
1735   }
1736   Lex.Lex(); // eat the name.
1737
1738   // If there are template args, parse them.
1739   if (Lex.getCode() == tgtok::less)
1740     if (ParseTemplateArgList(CurRec))
1741       return true;
1742
1743   // Finally, parse the object body.
1744   return ParseObjectBody(CurRec);
1745 }
1746
1747 /// ParseLetList - Parse a non-empty list of assignment expressions into a list
1748 /// of LetRecords.
1749 ///
1750 ///   LetList ::= LetItem (',' LetItem)*
1751 ///   LetItem ::= ID OptionalRangeList '=' Value
1752 ///
1753 std::vector<LetRecord> TGParser::ParseLetList() {
1754   std::vector<LetRecord> Result;
1755
1756   while (1) {
1757     if (Lex.getCode() != tgtok::Id) {
1758       TokError("expected identifier in let definition");
1759       return std::vector<LetRecord>();
1760     }
1761     std::string Name = Lex.getCurStrVal();
1762     SMLoc NameLoc = Lex.getLoc();
1763     Lex.Lex();  // Eat the identifier.
1764
1765     // Check for an optional RangeList.
1766     std::vector<unsigned> Bits;
1767     if (ParseOptionalRangeList(Bits))
1768       return std::vector<LetRecord>();
1769     std::reverse(Bits.begin(), Bits.end());
1770
1771     if (Lex.getCode() != tgtok::equal) {
1772       TokError("expected '=' in let expression");
1773       return std::vector<LetRecord>();
1774     }
1775     Lex.Lex();  // eat the '='.
1776
1777     Init *Val = ParseValue(0);
1778     if (Val == 0) return std::vector<LetRecord>();
1779
1780     // Now that we have everything, add the record.
1781     Result.push_back(LetRecord(Name, Bits, Val, NameLoc));
1782
1783     if (Lex.getCode() != tgtok::comma)
1784       return Result;
1785     Lex.Lex();  // eat the comma.
1786   }
1787 }
1788
1789 /// ParseTopLevelLet - Parse a 'let' at top level.  This can be a couple of
1790 /// different related productions. This works inside multiclasses too.
1791 ///
1792 ///   Object ::= LET LetList IN '{' ObjectList '}'
1793 ///   Object ::= LET LetList IN Object
1794 ///
1795 bool TGParser::ParseTopLevelLet(MultiClass *CurMultiClass) {
1796   assert(Lex.getCode() == tgtok::Let && "Unexpected token");
1797   Lex.Lex();
1798
1799   // Add this entry to the let stack.
1800   std::vector<LetRecord> LetInfo = ParseLetList();
1801   if (LetInfo.empty()) return true;
1802   LetStack.push_back(LetInfo);
1803
1804   if (Lex.getCode() != tgtok::In)
1805     return TokError("expected 'in' at end of top-level 'let'");
1806   Lex.Lex();
1807
1808   // If this is a scalar let, just handle it now
1809   if (Lex.getCode() != tgtok::l_brace) {
1810     // LET LetList IN Object
1811     if (ParseObject(CurMultiClass))
1812       return true;
1813   } else {   // Object ::= LETCommand '{' ObjectList '}'
1814     SMLoc BraceLoc = Lex.getLoc();
1815     // Otherwise, this is a group let.
1816     Lex.Lex();  // eat the '{'.
1817
1818     // Parse the object list.
1819     if (ParseObjectList(CurMultiClass))
1820       return true;
1821
1822     if (Lex.getCode() != tgtok::r_brace) {
1823       TokError("expected '}' at end of top level let command");
1824       return Error(BraceLoc, "to match this '{'");
1825     }
1826     Lex.Lex();
1827   }
1828
1829   // Outside this let scope, this let block is not active.
1830   LetStack.pop_back();
1831   return false;
1832 }
1833
1834 /// ParseMultiClass - Parse a multiclass definition.
1835 ///
1836 ///  MultiClassInst ::= MULTICLASS ID TemplateArgList?
1837 ///                     ':' BaseMultiClassList '{' MultiClassDef+ '}'
1838 ///
1839 bool TGParser::ParseMultiClass() {
1840   assert(Lex.getCode() == tgtok::MultiClass && "Unexpected token");
1841   Lex.Lex();  // Eat the multiclass token.
1842
1843   if (Lex.getCode() != tgtok::Id)
1844     return TokError("expected identifier after multiclass for name");
1845   std::string Name = Lex.getCurStrVal();
1846
1847   if (MultiClasses.count(Name))
1848     return TokError("multiclass '" + Name + "' already defined");
1849
1850   CurMultiClass = MultiClasses[Name] = new MultiClass(Name,
1851                                                       Lex.getLoc(), Records);
1852   Lex.Lex();  // Eat the identifier.
1853
1854   // If there are template args, parse them.
1855   if (Lex.getCode() == tgtok::less)
1856     if (ParseTemplateArgList(0))
1857       return true;
1858
1859   bool inherits = false;
1860
1861   // If there are submulticlasses, parse them.
1862   if (Lex.getCode() == tgtok::colon) {
1863     inherits = true;
1864
1865     Lex.Lex();
1866
1867     // Read all of the submulticlasses.
1868     SubMultiClassReference SubMultiClass =
1869       ParseSubMultiClassReference(CurMultiClass);
1870     while (1) {
1871       // Check for error.
1872       if (SubMultiClass.MC == 0) return true;
1873
1874       // Add it.
1875       if (AddSubMultiClass(CurMultiClass, SubMultiClass))
1876         return true;
1877
1878       if (Lex.getCode() != tgtok::comma) break;
1879       Lex.Lex(); // eat ','.
1880       SubMultiClass = ParseSubMultiClassReference(CurMultiClass);
1881     }
1882   }
1883
1884   if (Lex.getCode() != tgtok::l_brace) {
1885     if (!inherits)
1886       return TokError("expected '{' in multiclass definition");
1887     else if (Lex.getCode() != tgtok::semi)
1888       return TokError("expected ';' in multiclass definition");
1889     else
1890       Lex.Lex();  // eat the ';'.
1891   } else {
1892     if (Lex.Lex() == tgtok::r_brace)  // eat the '{'.
1893       return TokError("multiclass must contain at least one def");
1894
1895     while (Lex.getCode() != tgtok::r_brace) {
1896       switch (Lex.getCode()) {
1897         default:
1898           return TokError("expected 'let', 'def' or 'defm' in multiclass body");
1899         case tgtok::Let:
1900         case tgtok::Def:
1901         case tgtok::Defm:
1902           if (ParseObject(CurMultiClass))
1903             return true;
1904          break;
1905       }
1906     }
1907     Lex.Lex();  // eat the '}'.
1908   }
1909
1910   CurMultiClass = 0;
1911   return false;
1912 }
1913
1914 /// ParseDefm - Parse the instantiation of a multiclass.
1915 ///
1916 ///   DefMInst ::= DEFM ID ':' DefmSubClassRef ';'
1917 ///
1918 bool TGParser::ParseDefm(MultiClass *CurMultiClass) {
1919   assert(Lex.getCode() == tgtok::Defm && "Unexpected token!");
1920
1921   std::string DefmPrefix;
1922   if (Lex.Lex() == tgtok::Id) {  // eat the defm.
1923     DefmPrefix = Lex.getCurStrVal();
1924     Lex.Lex();  // Eat the defm prefix.
1925   }
1926
1927   SMLoc DefmPrefixLoc = Lex.getLoc();
1928   if (Lex.getCode() != tgtok::colon)
1929     return TokError("expected ':' after defm identifier");
1930
1931   // Keep track of the new generated record definitions.
1932   std::vector<Record*> NewRecDefs;
1933
1934   // This record also inherits from a regular class (non-multiclass)?
1935   bool InheritFromClass = false;
1936
1937   // eat the colon.
1938   Lex.Lex();
1939
1940   SMLoc SubClassLoc = Lex.getLoc();
1941   SubClassReference Ref = ParseSubClassReference(0, true);
1942
1943   while (1) {
1944     if (Ref.Rec == 0) return true;
1945
1946     // To instantiate a multiclass, we need to first get the multiclass, then
1947     // instantiate each def contained in the multiclass with the SubClassRef
1948     // template parameters.
1949     MultiClass *MC = MultiClasses[Ref.Rec->getName()];
1950     assert(MC && "Didn't lookup multiclass correctly?");
1951     std::vector<Init*> &TemplateVals = Ref.TemplateArgs;
1952
1953     // Verify that the correct number of template arguments were specified.
1954     const std::vector<std::string> &TArgs = MC->Rec.getTemplateArgs();
1955     if (TArgs.size() < TemplateVals.size())
1956       return Error(SubClassLoc,
1957                    "more template args specified than multiclass expects");
1958
1959     // Loop over all the def's in the multiclass, instantiating each one.
1960     for (unsigned i = 0, e = MC->DefPrototypes.size(); i != e; ++i) {
1961       Record *DefProto = MC->DefPrototypes[i];
1962
1963       // Add in the defm name.  If the defm prefix is empty, give each
1964       // instantiated def a unique name.  Otherwise, if "#NAME#" exists in the
1965       // name, substitute the prefix for #NAME#.  Otherwise, use the defm name
1966       // as a prefix.
1967       std::string DefName = DefProto->getName();
1968       if (DefmPrefix.empty()) {
1969         DefName = GetNewAnonymousName();
1970       } else {
1971         std::string::size_type idx = DefName.find("#NAME#");
1972         if (idx != std::string::npos) {
1973           DefName.replace(idx, 6, DefmPrefix);
1974         } else {
1975           // Add the suffix to the defm name to get the new name.
1976           DefName = DefmPrefix + DefName;
1977         }
1978       }
1979
1980       Record *CurRec = new Record(DefName, DefmPrefixLoc, Records);
1981
1982       SubClassReference Ref;
1983       Ref.RefLoc = DefmPrefixLoc;
1984       Ref.Rec = DefProto;
1985       AddSubClass(CurRec, Ref);
1986
1987       // Loop over all of the template arguments, setting them to the specified
1988       // value or leaving them as the default if necessary.
1989       for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
1990         // Check if a value is specified for this temp-arg.
1991         if (i < TemplateVals.size()) {
1992           // Set it now.
1993           if (SetValue(CurRec, DefmPrefixLoc, TArgs[i], std::vector<unsigned>(),
1994                        TemplateVals[i]))
1995             return true;
1996
1997           // Resolve it next.
1998           CurRec->resolveReferencesTo(CurRec->getValue(TArgs[i]));
1999
2000           // Now remove it.
2001           CurRec->removeValue(TArgs[i]);
2002
2003         } else if (!CurRec->getValue(TArgs[i])->getValue()->isComplete()) {
2004           return Error(SubClassLoc,
2005                        "value not specified for template argument #"+
2006                        utostr(i) + " (" + TArgs[i] + ") of multiclassclass '" +
2007                        MC->Rec.getName() + "'");
2008         }
2009       }
2010
2011       // If the mdef is inside a 'let' expression, add to each def.
2012       for (unsigned i = 0, e = LetStack.size(); i != e; ++i)
2013         for (unsigned j = 0, e = LetStack[i].size(); j != e; ++j)
2014           if (SetValue(CurRec, LetStack[i][j].Loc, LetStack[i][j].Name,
2015                        LetStack[i][j].Bits, LetStack[i][j].Value)) {
2016             Error(DefmPrefixLoc, "when instantiating this defm");
2017             return true;
2018           }
2019
2020       // Ensure redefinition doesn't happen.
2021       if (Records.getDef(CurRec->getName()))
2022         return Error(DefmPrefixLoc, "def '" + CurRec->getName() +
2023                      "' already defined, instantiating defm with subdef '" +
2024                      DefProto->getName() + "'");
2025
2026       // Don't create a top level definition for defm inside multiclasses,
2027       // instead, only update the prototypes and bind the template args
2028       // with the new created definition.
2029       if (CurMultiClass) {
2030         for (unsigned i = 0, e = CurMultiClass->DefPrototypes.size();
2031              i != e; ++i) {
2032           if (CurMultiClass->DefPrototypes[i]->getName() == CurRec->getName()) {
2033             Error(DefmPrefixLoc, "defm '" + CurRec->getName() +
2034                   "' already defined in this multiclass!");
2035             return 0;
2036           }
2037         }
2038         CurMultiClass->DefPrototypes.push_back(CurRec);
2039
2040         // Copy the template arguments for the multiclass into the new def.
2041         const std::vector<std::string> &TA =
2042           CurMultiClass->Rec.getTemplateArgs();
2043
2044         for (unsigned i = 0, e = TA.size(); i != e; ++i) {
2045           const RecordVal *RV = CurMultiClass->Rec.getValue(TA[i]);
2046           assert(RV && "Template arg doesn't exist?");
2047           CurRec->addValue(*RV);
2048         }
2049       } else {
2050         Records.addDef(CurRec);
2051       }
2052
2053       NewRecDefs.push_back(CurRec);
2054     }
2055
2056     if (Lex.getCode() != tgtok::comma) break;
2057     Lex.Lex(); // eat ','.
2058
2059     SubClassLoc = Lex.getLoc();
2060
2061     // A defm can inherit from regular classes (non-multiclass) as
2062     // long as they come in the end of the inheritance list.
2063     InheritFromClass = (Records.getClass(Lex.getCurStrVal()) != 0);
2064
2065     if (InheritFromClass)
2066       break;
2067
2068     Ref = ParseSubClassReference(0, true);
2069   }
2070
2071   if (InheritFromClass) {
2072     // Process all the classes to inherit as if they were part of a
2073     // regular 'def' and inherit all record values.
2074     SubClassReference SubClass = ParseSubClassReference(0, false);
2075     while (1) {
2076       // Check for error.
2077       if (SubClass.Rec == 0) return true;
2078
2079       // Get the expanded definition prototypes and teach them about
2080       // the record values the current class to inherit has
2081       for (unsigned i = 0, e = NewRecDefs.size(); i != e; ++i) {
2082         Record *CurRec = NewRecDefs[i];
2083
2084         // Add it.
2085         if (AddSubClass(CurRec, SubClass))
2086           return true;
2087
2088         // Process any variables on the let stack.
2089         for (unsigned i = 0, e = LetStack.size(); i != e; ++i)
2090           for (unsigned j = 0, e = LetStack[i].size(); j != e; ++j)
2091             if (SetValue(CurRec, LetStack[i][j].Loc, LetStack[i][j].Name,
2092                          LetStack[i][j].Bits, LetStack[i][j].Value))
2093               return true;
2094       }
2095
2096       if (Lex.getCode() != tgtok::comma) break;
2097       Lex.Lex(); // eat ','.
2098       SubClass = ParseSubClassReference(0, false);
2099     }
2100   }
2101
2102   if (!CurMultiClass)
2103     for (unsigned i = 0, e = NewRecDefs.size(); i != e; ++i)
2104       NewRecDefs[i]->resolveReferences();
2105
2106   if (Lex.getCode() != tgtok::semi)
2107     return TokError("expected ';' at end of defm");
2108   Lex.Lex();
2109
2110   return false;
2111 }
2112
2113 /// ParseObject
2114 ///   Object ::= ClassInst
2115 ///   Object ::= DefInst
2116 ///   Object ::= MultiClassInst
2117 ///   Object ::= DefMInst
2118 ///   Object ::= LETCommand '{' ObjectList '}'
2119 ///   Object ::= LETCommand Object
2120 bool TGParser::ParseObject(MultiClass *MC) {
2121   switch (Lex.getCode()) {
2122   default:
2123     return TokError("Expected class, def, defm, multiclass or let definition");
2124   case tgtok::Let:   return ParseTopLevelLet(MC);
2125   case tgtok::Def:   return ParseDef(MC);
2126   case tgtok::Defm:  return ParseDefm(MC);
2127   case tgtok::Class: return ParseClass();
2128   case tgtok::MultiClass: return ParseMultiClass();
2129   }
2130 }
2131
2132 /// ParseObjectList
2133 ///   ObjectList :== Object*
2134 bool TGParser::ParseObjectList(MultiClass *MC) {
2135   while (isObjectStart(Lex.getCode())) {
2136     if (ParseObject(MC))
2137       return true;
2138   }
2139   return false;
2140 }
2141
2142 bool TGParser::ParseFile() {
2143   Lex.Lex(); // Prime the lexer.
2144   if (ParseObjectList()) return true;
2145
2146   // If we have unread input at the end of the file, report it.
2147   if (Lex.getCode() == tgtok::Eof)
2148     return false;
2149
2150   return TokError("Unexpected input at top level");
2151 }
2152