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 <algorithm>
  15
  16 #include "TGParser.h"
  17 #include "Record.h"
  18 #include "llvm/ADT/StringExtras.h"
  19 #include "llvm/Support/Streams.h"
  20 using namespace llvm;
  21
  22 //===----------------------------------------------------------------------===//
  23 // Support Code for the Semantic Actions.
  24 //===----------------------------------------------------------------------===//
  25
  26 namespace llvm {
  27 struct SubClassReference {
  28   TGLoc RefLoc;
  29   Record *Rec;
  30   std::vector<Init*> TemplateArgs;
  31   SubClassReference() : Rec(0) {}
  32
  33   bool isInvalid() const { return Rec == 0; }
  34 };
  35
  36 struct SubMultiClassReference {
  37   TGLoc RefLoc;
  38   MultiClass *MC;
  39   std::vector<Init*> TemplateArgs;
  40   SubMultiClassReference() : MC(0) {}
  41
  42   bool isInvalid() const { return MC == 0; }
  43   void dump() const;
  44 };
  45
  46 void SubMultiClassReference::dump() const {
  47   cerr << "Multiclass:\n";
  48
  49   MC->dump();
  50
  51   cerr << "Template args:\n";
  52   for (std::vector<Init *>::const_iterator i = TemplateArgs.begin(),
  53          iend = TemplateArgs.end();
  54        i != iend;
  55        ++i) {
  56     (*i)->dump();
  57   }
  58 }
  59
  60 } // end namespace llvm
  61
  62 bool TGParser::AddValue(Record *CurRec, TGLoc Loc, const RecordVal &RV) {
  63   if (CurRec == 0)
  64     CurRec = &CurMultiClass->Rec;
  65
  66   if (RecordVal *ERV = CurRec->getValue(RV.getName())) {
  67     // The value already exists in the class, treat this as a set.
  68     if (ERV->setValue(RV.getValue()))
  69       return Error(Loc, "New definition of '" + RV.getName() + "' of type '" +
  70                    RV.getType()->getAsString() + "' is incompatible with " +
  71                    "previous definition of type '" +
  72                    ERV->getType()->getAsString() + "'");
  73   } else {
  74     CurRec->addValue(RV);
  75   }
  76   return false;
  77 }
  78
  79 /// SetValue -
  80 /// Return true on error, false on success.
  81 bool TGParser::SetValue(Record *CurRec, TGLoc Loc, const std::string &ValName,
  82                         const std::vector<unsigned> &BitList, Init *V) {
  83   if (!V) return false;
  84
  85   if (CurRec == 0) CurRec = &CurMultiClass->Rec;
  86
  87   RecordVal *RV = CurRec->getValue(ValName);
  88   if (RV == 0)
  89     return Error(Loc, "Value '" + ValName + "' unknown!");
  90
  91   // Do not allow assignments like 'X = X'.  This will just cause infinite loops
  92   // in the resolution machinery.
  93   if (BitList.empty())
  94     if (VarInit *VI = dynamic_cast<VarInit*>(V))
  95       if (VI->getName() == ValName)
  96         return false;
  97
  98   // If we are assigning to a subset of the bits in the value... then we must be
  99   // assigning to a field of BitsRecTy, which must have a BitsInit
 100   // initializer.
 101   //
 102   if (!BitList.empty()) {
 103     BitsInit *CurVal = dynamic_cast<BitsInit*>(RV->getValue());
 104     if (CurVal == 0)
 105       return Error(Loc, "Value '" + ValName + "' is not a bits type");
 106
 107     // Convert the incoming value to a bits type of the appropriate size...
 108     Init *BI = V->convertInitializerTo(new BitsRecTy(BitList.size()));
 109     if (BI == 0) {
 110       V->convertInitializerTo(new BitsRecTy(BitList.size()));
 111       return Error(Loc, "Initializer is not compatible with bit range");
 112     }
 113
 114     // We should have a BitsInit type now.
 115     BitsInit *BInit = dynamic_cast<BitsInit*>(BI);
 116     assert(BInit != 0);
 117
 118     BitsInit *NewVal = new BitsInit(CurVal->getNumBits());
 119
 120     // Loop over bits, assigning values as appropriate.
 121     for (unsigned i = 0, e = BitList.size(); i != e; ++i) {
 122       unsigned Bit = BitList[i];
 123       if (NewVal->getBit(Bit))
 124         return Error(Loc, "Cannot set bit #" + utostr(Bit) + " of value '" +
 125                      ValName + "' more than once");
 126       NewVal->setBit(Bit, BInit->getBit(i));
 127     }
 128
 129     for (unsigned i = 0, e = CurVal->getNumBits(); i != e; ++i)
 130       if (NewVal->getBit(i) == 0)
 131         NewVal->setBit(i, CurVal->getBit(i));
 132
 133     V = NewVal;
 134   }
 135
 136   if (RV->setValue(V))
 137    return Error(Loc, "Value '" + ValName + "' of type '" +
 138                 RV->getType()->getAsString() +
 139                 "' is incompatible with initializer '" + V->getAsString() +"'");
 140   return false;
 141 }
 142
 143 /// AddSubClass - Add SubClass as a subclass to CurRec, resolving its template
 144 /// args as SubClass's template arguments.
 145 bool TGParser::AddSubClass(Record *CurRec, SubClassReference &SubClass) {
 146   Record *SC = SubClass.Rec;
 147   // Add all of the values in the subclass into the current class.
 148   const std::vector<RecordVal> &Vals = SC->getValues();
 149   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 150     if (AddValue(CurRec, SubClass.RefLoc, Vals[i]))
 151       return true;
 152
 153   const std::vector<std::string> &TArgs = SC->getTemplateArgs();
 154
 155   // Ensure that an appropriate number of template arguments are specified.
 156   if (TArgs.size() < SubClass.TemplateArgs.size())
 157     return Error(SubClass.RefLoc, "More template args specified than expected");
 158
 159   // Loop over all of the template arguments, setting them to the specified
 160   // value or leaving them as the default if necessary.
 161   for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
 162     if (i < SubClass.TemplateArgs.size()) {
 163       // If a value is specified for this template arg, set it now.
 164       if (SetValue(CurRec, SubClass.RefLoc, TArgs[i], std::vector<unsigned>(),
 165                    SubClass.TemplateArgs[i]))
 166         return true;
 167
 168       // Resolve it next.
 169       CurRec->resolveReferencesTo(CurRec->getValue(TArgs[i]));
 170
 171       // Now remove it.
 172       CurRec->removeValue(TArgs[i]);
 173
 174     } else if (!CurRec->getValue(TArgs[i])->getValue()->isComplete()) {
 175       return Error(SubClass.RefLoc,"Value not specified for template argument #"
 176                    + utostr(i) + " (" + TArgs[i] + ") of subclass '" +
 177                    SC->getName() + "'!");
 178     }
 179   }
 180
 181   // Since everything went well, we can now set the "superclass" list for the
 182   // current record.
 183   const std::vector<Record*> &SCs = SC->getSuperClasses();
 184   for (unsigned i = 0, e = SCs.size(); i != e; ++i) {
 185     if (CurRec->isSubClassOf(SCs[i]))
 186       return Error(SubClass.RefLoc,
 187                    "Already subclass of '" + SCs[i]->getName() + "'!\n");
 188     CurRec->addSuperClass(SCs[i]);
 189   }
 190
 191   if (CurRec->isSubClassOf(SC))
 192     return Error(SubClass.RefLoc,
 193                  "Already subclass of '" + SC->getName() + "'!\n");
 194   CurRec->addSuperClass(SC);
 195   return false;
 196 }
 197
 198 /// AddSubMultiClass - Add SubMultiClass as a subclass to
 199 /// CurMC, resolving its template args as SubMultiClass's
 200 /// template arguments.
 201 bool TGParser::AddSubMultiClass(MultiClass *CurMC,
 202                                 SubMultiClassReference &SubMultiClass) {
 203   MultiClass *SMC = SubMultiClass.MC;
 204   Record *CurRec = &CurMC->Rec;
 205
 206   const std::vector<RecordVal> &MCVals = CurRec->getValues();
 207
 208   // Add all of the values in the subclass into the current class.
 209   const std::vector<RecordVal> &SMCVals = SMC->Rec.getValues();
 210   for (unsigned i = 0, e = SMCVals.size(); i != e; ++i)
 211     if (AddValue(CurRec, SubMultiClass.RefLoc, SMCVals[i]))
 212       return true;
 213
 214   int newDefStart = CurMC->DefPrototypes.size();
 215
 216   // Add all of the defs in the subclass into the current multiclass.
 217   for (MultiClass::RecordVector::const_iterator i = SMC->DefPrototypes.begin(),
 218          iend = SMC->DefPrototypes.end();
 219        i != iend;
 220        ++i) {
 221     // Clone the def and add it to the current multiclass
 222     Record *NewDef = new Record(**i);
 223
 224     // Add all of the values in the superclass into the current def.
 225     for (unsigned i = 0, e = MCVals.size(); i != e; ++i)
 226       if (AddValue(NewDef, SubMultiClass.RefLoc, MCVals[i]))
 227         return true;
 228
 229     CurMC->DefPrototypes.push_back(NewDef);
 230   }
 231
 232   const std::vector<std::string> &SMCTArgs = SMC->Rec.getTemplateArgs();
 233
 234   // Ensure that an appropriate number of template arguments are
 235   // specified.
 236   if (SMCTArgs.size() < SubMultiClass.TemplateArgs.size())
 237     return Error(SubMultiClass.RefLoc,
 238                  "More template args specified than expected");
 239
 240   // Loop over all of the template arguments, setting them to the specified
 241   // value or leaving them as the default if necessary.
 242   for (unsigned i = 0, e = SMCTArgs.size(); i != e; ++i) {
 243     if (i < SubMultiClass.TemplateArgs.size()) {
 244       // If a value is specified for this template arg, set it in the
 245       // superclass now.
 246       if (SetValue(CurRec, SubMultiClass.RefLoc, SMCTArgs[i],
 247                    std::vector<unsigned>(),
 248                    SubMultiClass.TemplateArgs[i]))
 249         return true;
 250
 251       // Resolve it next.
 252       CurRec->resolveReferencesTo(CurRec->getValue(SMCTArgs[i]));
 253
 254       // Now remove it.
 255       CurRec->removeValue(SMCTArgs[i]);
 256
 257       // If a value is specified for this template arg, set it in the
 258       // new defs now.
 259       for (MultiClass::RecordVector::iterator j =
 260              CurMC->DefPrototypes.begin() + newDefStart,
 261              jend = CurMC->DefPrototypes.end();
 262            j != jend;
 263            ++j) {
 264         Record *Def = *j;
 265
 266         if (SetValue(Def, SubMultiClass.RefLoc, SMCTArgs[i],
 267                      std::vector<unsigned>(),
 268                      SubMultiClass.TemplateArgs[i]))
 269           return true;
 270
 271         // Resolve it next.
 272         Def->resolveReferencesTo(Def->getValue(SMCTArgs[i]));
 273
 274         // Now remove it
 275         Def->removeValue(SMCTArgs[i]);
 276       }
 277     } else if (!CurRec->getValue(SMCTArgs[i])->getValue()->isComplete()) {
 278       return Error(SubMultiClass.RefLoc,
 279                    "Value not specified for template argument #"
 280                    + utostr(i) + " (" + SMCTArgs[i] + ") of subclass '" +
 281                    SMC->Rec.getName() + "'!");
 282     }
 283   }
 284
 285   return false;
 286 }
 287
 288 //===----------------------------------------------------------------------===//
 289 // Parser Code
 290 //===----------------------------------------------------------------------===//
 291
 292 /// isObjectStart - Return true if this is a valid first token for an Object.
 293 static bool isObjectStart(tgtok::TokKind K) {
 294   return K == tgtok::Class || K == tgtok::Def ||
 295          K == tgtok::Defm || K == tgtok::Let || K == tgtok::MultiClass;
 296 }
 297
 298 /// ParseObjectName - If an object name is specified, return it.  Otherwise,
 299 /// return an anonymous name.
 300 ///   ObjectName ::= ID
 301 ///   ObjectName ::= /*empty*/
 302 ///
 303 std::string TGParser::ParseObjectName() {
 304   if (Lex.getCode() == tgtok::Id) {
 305     std::string Ret = Lex.getCurStrVal();
 306     Lex.Lex();
 307     return Ret;
 308   }
 309
 310   static unsigned AnonCounter = 0;
 311   return "anonymous."+utostr(AnonCounter++);
 312 }
 313
 314
 315 /// ParseClassID - Parse and resolve a reference to a class name.  This returns
 316 /// null on error.
 317 ///
 318 ///    ClassID ::= ID
 319 ///
 320 Record *TGParser::ParseClassID() {
 321   if (Lex.getCode() != tgtok::Id) {
 322     TokError("expected name for ClassID");
 323     return 0;
 324   }
 325
 326   Record *Result = Records.getClass(Lex.getCurStrVal());
 327   if (Result == 0)
 328     TokError("Couldn't find class '" + Lex.getCurStrVal() + "'");
 329
 330   Lex.Lex();
 331   return Result;
 332 }
 333
 334 /// ParseMultiClassID - Parse and resolve a reference to a multiclass name.
 335 /// This returns null on error.
 336 ///
 337 ///    MultiClassID ::= ID
 338 ///
 339 MultiClass *TGParser::ParseMultiClassID() {
 340   if (Lex.getCode() != tgtok::Id) {
 341     TokError("expected name for ClassID");
 342     return 0;
 343   }
 344
 345   MultiClass *Result = MultiClasses[Lex.getCurStrVal()];
 346   if (Result == 0)
 347     TokError("Couldn't find class '" + Lex.getCurStrVal() + "'");
 348
 349   Lex.Lex();
 350   return Result;
 351 }
 352
 353 Record *TGParser::ParseDefmID() {
 354   if (Lex.getCode() != tgtok::Id) {
 355     TokError("expected multiclass name");
 356     return 0;
 357   }
 358
 359   MultiClass *MC = MultiClasses[Lex.getCurStrVal()];
 360   if (MC == 0) {
 361     TokError("Couldn't find multiclass '" + Lex.getCurStrVal() + "'");
 362     return 0;
 363   }
 364
 365   Lex.Lex();
 366   return &MC->Rec;
 367 }
 368
 369
 370
 371 /// ParseSubClassReference - Parse a reference to a subclass or to a templated
 372 /// subclass.  This returns a SubClassRefTy with a null Record* on error.
 373 ///
 374 ///  SubClassRef ::= ClassID
 375 ///  SubClassRef ::= ClassID '<' ValueList '>'
 376 ///
 377 SubClassReference TGParser::
 378 ParseSubClassReference(Record *CurRec, bool isDefm) {
 379   SubClassReference Result;
 380   Result.RefLoc = Lex.getLoc();
 381
 382   if (isDefm)
 383     Result.Rec = ParseDefmID();
 384   else
 385     Result.Rec = ParseClassID();
 386   if (Result.Rec == 0) return Result;
 387
 388   // If there is no template arg list, we're done.
 389   if (Lex.getCode() != tgtok::less)
 390     return Result;
 391   Lex.Lex();  // Eat the '<'
 392
 393   if (Lex.getCode() == tgtok::greater) {
 394     TokError("subclass reference requires a non-empty list of template values");
 395     Result.Rec = 0;
 396     return Result;
 397   }
 398
 399   Result.TemplateArgs = ParseValueList(CurRec);
 400   if (Result.TemplateArgs.empty()) {
 401     Result.Rec = 0;   // Error parsing value list.
 402     return Result;
 403   }
 404
 405   if (Lex.getCode() != tgtok::greater) {
 406     TokError("expected '>' in template value list");
 407     Result.Rec = 0;
 408     return Result;
 409   }
 410   Lex.Lex();
 411
 412   return Result;
 413 }
 414
 415 /// ParseSubMultiClassReference - Parse a reference to a subclass or to a
 416 /// templated submulticlass.  This returns a SubMultiClassRefTy with a null
 417 /// Record* on error.
 418 ///
 419 ///  SubMultiClassRef ::= MultiClassID
 420 ///  SubMultiClassRef ::= MultiClassID '<' ValueList '>'
 421 ///
 422 SubMultiClassReference TGParser::
 423 ParseSubMultiClassReference(MultiClass *CurMC) {
 424   SubMultiClassReference Result;
 425   Result.RefLoc = Lex.getLoc();
 426
 427   Result.MC = ParseMultiClassID();
 428   if (Result.MC == 0) return Result;
 429
 430   // If there is no template arg list, we're done.
 431   if (Lex.getCode() != tgtok::less)
 432     return Result;
 433   Lex.Lex();  // Eat the '<'
 434
 435   if (Lex.getCode() == tgtok::greater) {
 436     TokError("subclass reference requires a non-empty list of template values");
 437     Result.MC = 0;
 438     return Result;
 439   }
 440
 441   Result.TemplateArgs = ParseValueList(&CurMC->Rec);
 442   if (Result.TemplateArgs.empty()) {
 443     Result.MC = 0;   // Error parsing value list.
 444     return Result;
 445   }
 446
 447   if (Lex.getCode() != tgtok::greater) {
 448     TokError("expected '>' in template value list");
 449     Result.MC = 0;
 450     return Result;
 451   }
 452   Lex.Lex();
 453
 454   return Result;
 455 }
 456
 457 /// ParseRangePiece - Parse a bit/value range.
 458 ///   RangePiece ::= INTVAL
 459 ///   RangePiece ::= INTVAL '-' INTVAL
 460 ///   RangePiece ::= INTVAL INTVAL
 461 bool TGParser::ParseRangePiece(std::vector<unsigned> &Ranges) {
 462   if (Lex.getCode() != tgtok::IntVal) {
 463     TokError("expected integer or bitrange");
 464     return true;
 465   }
 466   int64_t Start = Lex.getCurIntVal();
 467   int64_t End;
 468
 469   if (Start < 0)
 470     return TokError("invalid range, cannot be negative");
 471
 472   switch (Lex.Lex()) {  // eat first character.
 473   default:
 474     Ranges.push_back(Start);
 475     return false;
 476   case tgtok::minus:
 477     if (Lex.Lex() != tgtok::IntVal) {
 478       TokError("expected integer value as end of range");
 479       return true;
 480     }
 481     End = Lex.getCurIntVal();
 482     break;
 483   case tgtok::IntVal:
 484     End = -Lex.getCurIntVal();
 485     break;
 486   }
 487   if (End < 0)
 488     return TokError("invalid range, cannot be negative");
 489   Lex.Lex();
 490
 491   // Add to the range.
 492   if (Start < End) {
 493     for (; Start <= End; ++Start)
 494       Ranges.push_back(Start);
 495   } else {
 496     for (; Start >= End; --Start)
 497       Ranges.push_back(Start);
 498   }
 499   return false;
 500 }
 501
 502 /// ParseRangeList - Parse a list of scalars and ranges into scalar values.
 503 ///
 504 ///   RangeList ::= RangePiece (',' RangePiece)*
 505 ///
 506 std::vector<unsigned> TGParser::ParseRangeList() {
 507   std::vector<unsigned> Result;
 508
 509   // Parse the first piece.
 510   if (ParseRangePiece(Result))
 511     return std::vector<unsigned>();
 512   while (Lex.getCode() == tgtok::comma) {
 513     Lex.Lex();  // Eat the comma.
 514
 515     // Parse the next range piece.
 516     if (ParseRangePiece(Result))
 517       return std::vector<unsigned>();
 518   }
 519   return Result;
 520 }
 521
 522 /// ParseOptionalRangeList - Parse either a range list in <>'s or nothing.
 523 ///   OptionalRangeList ::= '<' RangeList '>'
 524 ///   OptionalRangeList ::= /*empty*/
 525 bool TGParser::ParseOptionalRangeList(std::vector<unsigned> &Ranges) {
 526   if (Lex.getCode() != tgtok::less)
 527     return false;
 528
 529   TGLoc StartLoc = Lex.getLoc();
 530   Lex.Lex(); // eat the '<'
 531
 532   // Parse the range list.
 533   Ranges = ParseRangeList();
 534   if (Ranges.empty()) return true;
 535
 536   if (Lex.getCode() != tgtok::greater) {
 537     TokError("expected '>' at end of range list");
 538     return Error(StartLoc, "to match this '<'");
 539   }
 540   Lex.Lex();   // eat the '>'.
 541   return false;
 542 }
 543
 544 /// ParseOptionalBitList - Parse either a bit list in {}'s or nothing.
 545 ///   OptionalBitList ::= '{' RangeList '}'
 546 ///   OptionalBitList ::= /*empty*/
 547 bool TGParser::ParseOptionalBitList(std::vector<unsigned> &Ranges) {
 548   if (Lex.getCode() != tgtok::l_brace)
 549     return false;
 550
 551   TGLoc StartLoc = Lex.getLoc();
 552   Lex.Lex(); // eat the '{'
 553
 554   // Parse the range list.
 555   Ranges = ParseRangeList();
 556   if (Ranges.empty()) return true;
 557
 558   if (Lex.getCode() != tgtok::r_brace) {
 559     TokError("expected '}' at end of bit list");
 560     return Error(StartLoc, "to match this '{'");
 561   }
 562   Lex.Lex();   // eat the '}'.
 563   return false;
 564 }
 565
 566
 567 /// ParseType - Parse and return a tblgen type.  This returns null on error.
 568 ///
 569 ///   Type ::= STRING                       // string type
 570 ///   Type ::= BIT                          // bit type
 571 ///   Type ::= BITS '<' INTVAL '>'          // bits<x> type
 572 ///   Type ::= INT                          // int type
 573 ///   Type ::= LIST '<' Type '>'            // list<x> type
 574 ///   Type ::= CODE                         // code type
 575 ///   Type ::= DAG                          // dag type
 576 ///   Type ::= ClassID                      // Record Type
 577 ///
 578 RecTy *TGParser::ParseType() {
 579   switch (Lex.getCode()) {
 580   default: TokError("Unknown token when expecting a type"); return 0;
 581   case tgtok::String: Lex.Lex(); return new StringRecTy();
 582   case tgtok::Bit:    Lex.Lex(); return new BitRecTy();
 583   case tgtok::Int:    Lex.Lex(); return new IntRecTy();
 584   case tgtok::Code:   Lex.Lex(); return new CodeRecTy();
 585   case tgtok::Dag:    Lex.Lex(); return new DagRecTy();
 586   case tgtok::Id:
 587     if (Record *R = ParseClassID()) return new RecordRecTy(R);
 588     return 0;
 589   case tgtok::Bits: {
 590     if (Lex.Lex() != tgtok::less) { // Eat 'bits'
 591       TokError("expected '<' after bits type");
 592       return 0;
 593     }
 594     if (Lex.Lex() != tgtok::IntVal) {  // Eat '<'
 595       TokError("expected integer in bits<n> type");
 596       return 0;
 597     }
 598     uint64_t Val = Lex.getCurIntVal();
 599     if (Lex.Lex() != tgtok::greater) {  // Eat count.
 600       TokError("expected '>' at end of bits<n> type");
 601       return 0;
 602     }
 603     Lex.Lex();  // Eat '>'
 604     return new BitsRecTy(Val);
 605   }
 606   case tgtok::List: {
 607     if (Lex.Lex() != tgtok::less) { // Eat 'bits'
 608       TokError("expected '<' after list type");
 609       return 0;
 610     }
 611     Lex.Lex();  // Eat '<'
 612     RecTy *SubType = ParseType();
 613     if (SubType == 0) return 0;
 614
 615     if (Lex.getCode() != tgtok::greater) {
 616       TokError("expected '>' at end of list<ty> type");
 617       return 0;
 618     }
 619     Lex.Lex();  // Eat '>'
 620     return new ListRecTy(SubType);
 621   }
 622   }
 623 }
 624
 625 /// ParseIDValue - Parse an ID as a value and decode what it means.
 626 ///
 627 ///  IDValue ::= ID [def local value]
 628 ///  IDValue ::= ID [def template arg]
 629 ///  IDValue ::= ID [multiclass local value]
 630 ///  IDValue ::= ID [multiclass template argument]
 631 ///  IDValue ::= ID [def name]
 632 ///
 633 Init *TGParser::ParseIDValue(Record *CurRec) {
 634   assert(Lex.getCode() == tgtok::Id && "Expected ID in ParseIDValue");
 635   std::string Name = Lex.getCurStrVal();
 636   TGLoc Loc = Lex.getLoc();
 637   Lex.Lex();
 638   return ParseIDValue(CurRec, Name, Loc);
 639 }
 640
 641 /// ParseIDValue - This is just like ParseIDValue above, but it assumes the ID
 642 /// has already been read.
 643 Init *TGParser::ParseIDValue(Record *CurRec,
 644                              const std::string &Name, TGLoc NameLoc) {
 645   if (CurRec) {
 646     if (const RecordVal *RV = CurRec->getValue(Name))
 647       return new VarInit(Name, RV->getType());
 648
 649     std::string TemplateArgName = CurRec->getName()+":"+Name;
 650     if (CurRec->isTemplateArg(TemplateArgName)) {
 651       const RecordVal *RV = CurRec->getValue(TemplateArgName);
 652       assert(RV && "Template arg doesn't exist??");
 653       return new VarInit(TemplateArgName, RV->getType());
 654     }
 655   }
 656
 657   if (CurMultiClass) {
 658     std::string MCName = CurMultiClass->Rec.getName()+"::"+Name;
 659     if (CurMultiClass->Rec.isTemplateArg(MCName)) {
 660       const RecordVal *RV = CurMultiClass->Rec.getValue(MCName);
 661       assert(RV && "Template arg doesn't exist??");
 662       return new VarInit(MCName, RV->getType());
 663     }
 664   }
 665
 666   if (Record *D = Records.getDef(Name))
 667     return new DefInit(D);
 668
 669   Error(NameLoc, "Variable not defined: '" + Name + "'");
 670   return 0;
 671 }
 672
 673 /// ParseSimpleValue - Parse a tblgen value.  This returns null on error.
 674 ///
 675 ///   SimpleValue ::= IDValue
 676 ///   SimpleValue ::= INTVAL
 677 ///   SimpleValue ::= STRVAL+
 678 ///   SimpleValue ::= CODEFRAGMENT
 679 ///   SimpleValue ::= '?'
 680 ///   SimpleValue ::= '{' ValueList '}'
 681 ///   SimpleValue ::= ID '<' ValueListNE '>'
 682 ///   SimpleValue ::= '[' ValueList ']'
 683 ///   SimpleValue ::= '(' IDValue DagArgList ')'
 684 ///   SimpleValue ::= CONCATTOK '(' Value ',' Value ')'
 685 ///   SimpleValue ::= SHLTOK '(' Value ',' Value ')'
 686 ///   SimpleValue ::= SRATOK '(' Value ',' Value ')'
 687 ///   SimpleValue ::= SRLTOK '(' Value ',' Value ')'
 688 ///   SimpleValue ::= STRCONCATTOK '(' Value ',' Value ')'
 689 ///
 690 Init *TGParser::ParseSimpleValue(Record *CurRec) {
 691   Init *R = 0;
 692   switch (Lex.getCode()) {
 693   default: TokError("Unknown token when parsing a value"); break;
 694   case tgtok::IntVal: R = new IntInit(Lex.getCurIntVal()); Lex.Lex(); break;
 695   case tgtok::StrVal: {
 696     std::string Val = Lex.getCurStrVal();
 697     Lex.Lex();
 698
 699     // Handle multiple consecutive concatenated strings.
 700     while (Lex.getCode() == tgtok::StrVal) {
 701       Val += Lex.getCurStrVal();
 702       Lex.Lex();
 703     }
 704
 705     R = new StringInit(Val);
 706     break;
 707   }
 708   case tgtok::CodeFragment:
 709       R = new CodeInit(Lex.getCurStrVal()); Lex.Lex(); break;
 710   case tgtok::question: R = new UnsetInit(); Lex.Lex(); break;
 711   case tgtok::Id: {
 712     TGLoc NameLoc = Lex.getLoc();
 713     std::string Name = Lex.getCurStrVal();
 714     if (Lex.Lex() != tgtok::less)  // consume the Id.
 715       return ParseIDValue(CurRec, Name, NameLoc);    // Value ::= IDValue
 716
 717     // Value ::= ID '<' ValueListNE '>'
 718     if (Lex.Lex() == tgtok::greater) {
 719       TokError("expected non-empty value list");
 720       return 0;
 721     }
 722     std::vector<Init*> ValueList = ParseValueList(CurRec);
 723     if (ValueList.empty()) return 0;
 724
 725     if (Lex.getCode() != tgtok::greater) {
 726       TokError("expected '>' at end of value list");
 727       return 0;
 728     }
 729     Lex.Lex();  // eat the '>'
 730
 731     // This is a CLASS<initvalslist> expression.  This is supposed to synthesize
 732     // a new anonymous definition, deriving from CLASS<initvalslist> with no
 733     // body.
 734     Record *Class = Records.getClass(Name);
 735     if (!Class) {
 736       Error(NameLoc, "Expected a class name, got '" + Name + "'");
 737       return 0;
 738     }
 739
 740     // Create the new record, set it as CurRec temporarily.
 741     static unsigned AnonCounter = 0;
 742     Record *NewRec = new Record("anonymous.val."+utostr(AnonCounter++),NameLoc);
 743     SubClassReference SCRef;
 744     SCRef.RefLoc = NameLoc;
 745     SCRef.Rec = Class;
 746     SCRef.TemplateArgs = ValueList;
 747     // Add info about the subclass to NewRec.
 748     if (AddSubClass(NewRec, SCRef))
 749       return 0;
 750     NewRec->resolveReferences();
 751     Records.addDef(NewRec);
 752
 753     // The result of the expression is a reference to the new record.
 754     return new DefInit(NewRec);
 755   }
 756   case tgtok::l_brace: {           // Value ::= '{' ValueList '}'
 757     TGLoc BraceLoc = Lex.getLoc();
 758     Lex.Lex(); // eat the '{'
 759     std::vector<Init*> Vals;
 760
 761     if (Lex.getCode() != tgtok::r_brace) {
 762       Vals = ParseValueList(CurRec);
 763       if (Vals.empty()) return 0;
 764     }
 765     if (Lex.getCode() != tgtok::r_brace) {
 766       TokError("expected '}' at end of bit list value");
 767       return 0;
 768     }
 769     Lex.Lex();  // eat the '}'
 770
 771     BitsInit *Result = new BitsInit(Vals.size());
 772     for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 773       Init *Bit = Vals[i]->convertInitializerTo(new BitRecTy());
 774       if (Bit == 0) {
 775         Error(BraceLoc, "Element #" + utostr(i) + " (" + Vals[i]->getAsString()+
 776               ") is not convertable to a bit");
 777         return 0;
 778       }
 779       Result->setBit(Vals.size()-i-1, Bit);
 780     }
 781     return Result;
 782   }
 783   case tgtok::l_square: {          // Value ::= '[' ValueList ']'
 784     Lex.Lex(); // eat the '['
 785     std::vector<Init*> Vals;
 786
 787     if (Lex.getCode() != tgtok::r_square) {
 788       Vals = ParseValueList(CurRec);
 789       if (Vals.empty()) return 0;
 790     }
 791     if (Lex.getCode() != tgtok::r_square) {
 792       TokError("expected ']' at end of list value");
 793       return 0;
 794     }
 795     Lex.Lex();  // eat the ']'
 796     return new ListInit(Vals);
 797   }
 798   case tgtok::l_paren: {         // Value ::= '(' IDValue DagArgList ')'
 799     Lex.Lex();   // eat the '('
 800     if (Lex.getCode() != tgtok::Id
 801         && Lex.getCode() != tgtok::XNameConcat) {
 802       TokError("expected identifier in dag init");
 803       return 0;
 804     }
 805
 806     Init *Operator = 0;
 807     if (Lex.getCode() == tgtok::Id) {
 808       Operator = ParseIDValue(CurRec);
 809       if (Operator == 0) return 0;
 810     }
 811     else {
 812       BinOpInit::BinaryOp Code = BinOpInit::NAMECONCAT;
 813
 814       Lex.Lex();  // eat the operation
 815
 816       if (Lex.getCode() != tgtok::less) {
 817         TokError("expected type name for nameconcat");
 818         return 0;
 819       }
 820       Lex.Lex();  // eat the <
 821
 822       RecTy *Type = ParseType();
 823
 824       if (Type == 0) {
 825         TokError("expected type name for nameconcat");
 826         return 0;
 827       }
 828
 829       if (Lex.getCode() != tgtok::greater) {
 830         TokError("expected type name for nameconcat");
 831         return 0;
 832       }
 833       Lex.Lex();  // eat the >
 834
 835       if (Lex.getCode() != tgtok::l_paren) {
 836         TokError("expected '(' after binary operator");
 837         return 0;
 838       }
 839       Lex.Lex();  // eat the '('
 840
 841       Init *LHS = ParseValue(CurRec);
 842       if (LHS == 0) return 0;
 843
 844       if (Lex.getCode() != tgtok::comma) {
 845         TokError("expected ',' in binary operator");
 846         return 0;
 847       }
 848       Lex.Lex();  // eat the ','
 849
 850       Init *RHS = ParseValue(CurRec);
 851        if (RHS == 0) return 0;
 852
 853        if (Lex.getCode() != tgtok::r_paren) {
 854          TokError("expected ')' in binary operator");
 855          return 0;
 856        }
 857        Lex.Lex();  // eat the ')'
 858        Operator = (new BinOpInit(Code, LHS, RHS, Type))->Fold(CurRec,
 859                                                               CurMultiClass);
 860     }
 861
 862     // If the operator name is present, parse it.
 863     std::string OperatorName;
 864     if (Lex.getCode() == tgtok::colon) {
 865       if (Lex.Lex() != tgtok::VarName) { // eat the ':'
 866         TokError("expected variable name in dag operator");
 867         return 0;
 868       }
 869       OperatorName = Lex.getCurStrVal();
 870       Lex.Lex();  // eat the VarName.
 871     }
 872
 873     std::vector<std::pair<llvm::Init*, std::string> > DagArgs;
 874     if (Lex.getCode() != tgtok::r_paren) {
 875       DagArgs = ParseDagArgList(CurRec);
 876       if (DagArgs.empty()) return 0;
 877     }
 878
 879     if (Lex.getCode() != tgtok::r_paren) {
 880       TokError("expected ')' in dag init");
 881       return 0;
 882     }
 883     Lex.Lex();  // eat the ')'
 884
 885     return new DagInit(Operator, OperatorName, DagArgs);
 886   }
 887   case tgtok::XConcat:
 888   case tgtok::XSRA:
 889   case tgtok::XSRL:
 890   case tgtok::XSHL:
 891   case tgtok::XStrConcat:
 892   case tgtok::XNameConcat: {  // Value ::= !binop '(' Value ',' Value ')'
 893     BinOpInit::BinaryOp Code;
 894     RecTy *Type = 0;
 895
 896
 897     switch (Lex.getCode()) {
 898     default: assert(0 && "Unhandled code!");
 899     case tgtok::XConcat:
 900       Lex.Lex();  // eat the operation
 901       Code = BinOpInit::CONCAT;
 902       Type = new DagRecTy();
 903       break;
 904     case tgtok::XSRA:
 905       Lex.Lex();  // eat the operation
 906       Code = BinOpInit::SRA;
 907       Type = new IntRecTy();
 908       break;
 909     case tgtok::XSRL:
 910       Lex.Lex();  // eat the operation
 911       Code = BinOpInit::SRL;
 912       Type = new IntRecTy();
 913       break;
 914     case tgtok::XSHL:
 915       Lex.Lex();  // eat the operation
 916       Code = BinOpInit::SHL;
 917       Type = new IntRecTy();
 918       break;
 919     case tgtok::XStrConcat:
 920       Lex.Lex();  // eat the operation
 921       Code = BinOpInit::STRCONCAT;
 922       Type = new StringRecTy();
 923       break;
 924     case tgtok::XNameConcat:
 925       Lex.Lex();  // eat the operation
 926       Code = BinOpInit::NAMECONCAT;
 927       if (Lex.getCode() != tgtok::less) {
 928         TokError("expected type name for nameconcat");
 929         return 0;
 930       }
 931       Lex.Lex();  // eat the <
 932
 933       Type = ParseType();
 934
 935       if (Type == 0) {
 936         TokError("expected type name for nameconcat");
 937         return 0;
 938       }
 939
 940       if (Lex.getCode() != tgtok::greater) {
 941         TokError("expected type name for nameconcat");
 942         return 0;
 943       }
 944       Lex.Lex();  // eat the >
 945       break;
 946     }
 947     if (Lex.getCode() != tgtok::l_paren) {
 948       TokError("expected '(' after binary operator");
 949       return 0;
 950     }
 951     Lex.Lex();  // eat the '('
 952
 953     Init *LHS = ParseValue(CurRec);
 954     if (LHS == 0) return 0;
 955
 956     if (Lex.getCode() != tgtok::comma) {
 957       TokError("expected ',' in binary operator");
 958       return 0;
 959     }
 960     Lex.Lex();  // eat the ','
 961
 962     Init *RHS = ParseValue(CurRec);
 963     if (RHS == 0) return 0;
 964
 965     if (Lex.getCode() != tgtok::r_paren) {
 966       TokError("expected ')' in binary operator");
 967       return 0;
 968     }
 969     Lex.Lex();  // eat the ')'
 970     return (new BinOpInit(Code, LHS, RHS, Type))->Fold(CurRec, CurMultiClass);
 971   }
 972   }
 973
 974   return R;
 975 }
 976
 977 /// ParseValue - Parse a tblgen value.  This returns null on error.
 978 ///
 979 ///   Value       ::= SimpleValue ValueSuffix*
 980 ///   ValueSuffix ::= '{' BitList '}'
 981 ///   ValueSuffix ::= '[' BitList ']'
 982 ///   ValueSuffix ::= '.' ID
 983 ///
 984 Init *TGParser::ParseValue(Record *CurRec) {
 985   Init *Result = ParseSimpleValue(CurRec);
 986   if (Result == 0) return 0;
 987
 988   // Parse the suffixes now if present.
 989   while (1) {
 990     switch (Lex.getCode()) {
 991     default: return Result;
 992     case tgtok::l_brace: {
 993       TGLoc CurlyLoc = Lex.getLoc();
 994       Lex.Lex(); // eat the '{'
 995       std::vector<unsigned> Ranges = ParseRangeList();
 996       if (Ranges.empty()) return 0;
 997
 998       // Reverse the bitlist.
 999       std::reverse(Ranges.begin(), Ranges.end());
1000       Result = Result->convertInitializerBitRange(Ranges);
1001       if (Result == 0) {
1002         Error(CurlyLoc, "Invalid bit range for value");
1003         return 0;
1004       }
1005
1006       // Eat the '}'.
1007       if (Lex.getCode() != tgtok::r_brace) {
1008         TokError("expected '}' at end of bit range list");
1009         return 0;
1010       }
1011       Lex.Lex();
1012       break;
1013     }
1014     case tgtok::l_square: {
1015       TGLoc SquareLoc = Lex.getLoc();
1016       Lex.Lex(); // eat the '['
1017       std::vector<unsigned> Ranges = ParseRangeList();
1018       if (Ranges.empty()) return 0;
1019
1020       Result = Result->convertInitListSlice(Ranges);
1021       if (Result == 0) {
1022         Error(SquareLoc, "Invalid range for list slice");
1023         return 0;
1024       }
1025
1026       // Eat the ']'.
1027       if (Lex.getCode() != tgtok::r_square) {
1028         TokError("expected ']' at end of list slice");
1029         return 0;
1030       }
1031       Lex.Lex();
1032       break;
1033     }
1034     case tgtok::period:
1035       if (Lex.Lex() != tgtok::Id) {  // eat the .
1036         TokError("expected field identifier after '.'");
1037         return 0;
1038       }
1039       if (!Result->getFieldType(Lex.getCurStrVal())) {
1040         TokError("Cannot access field '" + Lex.getCurStrVal() + "' of value '" +
1041                  Result->getAsString() + "'");
1042         return 0;
1043       }
1044       Result = new FieldInit(Result, Lex.getCurStrVal());
1045       Lex.Lex();  // eat field name
1046       break;
1047     }
1048   }
1049 }
1050
1051 /// ParseDagArgList - Parse the argument list for a dag literal expression.
1052 ///
1053 ///    ParseDagArgList ::= Value (':' VARNAME)?
1054 ///    ParseDagArgList ::= ParseDagArgList ',' Value (':' VARNAME)?
1055 std::vector<std::pair<llvm::Init*, std::string> >
1056 TGParser::ParseDagArgList(Record *CurRec) {
1057   std::vector<std::pair<llvm::Init*, std::string> > Result;
1058
1059   while (1) {
1060     Init *Val = ParseValue(CurRec);
1061     if (Val == 0) return std::vector<std::pair<llvm::Init*, std::string> >();
1062
1063     // If the variable name is present, add it.
1064     std::string VarName;
1065     if (Lex.getCode() == tgtok::colon) {
1066       if (Lex.Lex() != tgtok::VarName) { // eat the ':'
1067         TokError("expected variable name in dag literal");
1068         return std::vector<std::pair<llvm::Init*, std::string> >();
1069       }
1070       VarName = Lex.getCurStrVal();
1071       Lex.Lex();  // eat the VarName.
1072     }
1073
1074     Result.push_back(std::make_pair(Val, VarName));
1075
1076     if (Lex.getCode() != tgtok::comma) break;
1077     Lex.Lex(); // eat the ','
1078   }
1079
1080   return Result;
1081 }
1082
1083
1084 /// ParseValueList - Parse a comma separated list of values, returning them as a
1085 /// vector.  Note that this always expects to be able to parse at least one
1086 /// value.  It returns an empty list if this is not possible.
1087 ///
1088 ///   ValueList ::= Value (',' Value)
1089 ///
1090 std::vector<Init*> TGParser::ParseValueList(Record *CurRec) {
1091   std::vector<Init*> Result;
1092   Result.push_back(ParseValue(CurRec));
1093   if (Result.back() == 0) return std::vector<Init*>();
1094
1095   while (Lex.getCode() == tgtok::comma) {
1096     Lex.Lex();  // Eat the comma
1097
1098     Result.push_back(ParseValue(CurRec));
1099     if (Result.back() == 0) return std::vector<Init*>();
1100   }
1101
1102   return Result;
1103 }
1104
1105
1106
1107 /// ParseDeclaration - Read a declaration, returning the name of field ID, or an
1108 /// empty string on error.  This can happen in a number of different context's,
1109 /// including within a def or in the template args for a def (which which case
1110 /// CurRec will be non-null) and within the template args for a multiclass (in
1111 /// which case CurRec will be null, but CurMultiClass will be set).  This can
1112 /// also happen within a def that is within a multiclass, which will set both
1113 /// CurRec and CurMultiClass.
1114 ///
1115 ///  Declaration ::= FIELD? Type ID ('=' Value)?
1116 ///
1117 std::string TGParser::ParseDeclaration(Record *CurRec,
1118                                        bool ParsingTemplateArgs) {
1119   // Read the field prefix if present.
1120   bool HasField = Lex.getCode() == tgtok::Field;
1121   if (HasField) Lex.Lex();
1122
1123   RecTy *Type = ParseType();
1124   if (Type == 0) return "";
1125
1126   if (Lex.getCode() != tgtok::Id) {
1127     TokError("Expected identifier in declaration");
1128     return "";
1129   }
1130
1131   TGLoc IdLoc = Lex.getLoc();
1132   std::string DeclName = Lex.getCurStrVal();
1133   Lex.Lex();
1134
1135   if (ParsingTemplateArgs) {
1136     if (CurRec) {
1137       DeclName = CurRec->getName() + ":" + DeclName;
1138     } else {
1139       assert(CurMultiClass);
1140     }
1141     if (CurMultiClass)
1142       DeclName = CurMultiClass->Rec.getName() + "::" + DeclName;
1143   }
1144
1145   // Add the value.
1146   if (AddValue(CurRec, IdLoc, RecordVal(DeclName, Type, HasField)))
1147     return "";
1148
1149   // If a value is present, parse it.
1150   if (Lex.getCode() == tgtok::equal) {
1151     Lex.Lex();
1152     TGLoc ValLoc = Lex.getLoc();
1153     Init *Val = ParseValue(CurRec);
1154     if (Val == 0 ||
1155         SetValue(CurRec, ValLoc, DeclName, std::vector<unsigned>(), Val))
1156       return "";
1157   }
1158
1159   return DeclName;
1160 }
1161
1162 /// ParseTemplateArgList - Read a template argument list, which is a non-empty
1163 /// sequence of template-declarations in <>'s.  If CurRec is non-null, these are
1164 /// template args for a def, which may or may not be in a multiclass.  If null,
1165 /// these are the template args for a multiclass.
1166 ///
1167 ///    TemplateArgList ::= '<' Declaration (',' Declaration)* '>'
1168 ///
1169 bool TGParser::ParseTemplateArgList(Record *CurRec) {
1170   assert(Lex.getCode() == tgtok::less && "Not a template arg list!");
1171   Lex.Lex(); // eat the '<'
1172
1173   Record *TheRecToAddTo = CurRec ? CurRec : &CurMultiClass->Rec;
1174
1175   // Read the first declaration.
1176   std::string TemplArg = ParseDeclaration(CurRec, true/*templateargs*/);
1177   if (TemplArg.empty())
1178     return true;
1179
1180   TheRecToAddTo->addTemplateArg(TemplArg);
1181
1182   while (Lex.getCode() == tgtok::comma) {
1183     Lex.Lex(); // eat the ','
1184
1185     // Read the following declarations.
1186     TemplArg = ParseDeclaration(CurRec, true/*templateargs*/);
1187     if (TemplArg.empty())
1188       return true;
1189     TheRecToAddTo->addTemplateArg(TemplArg);
1190   }
1191
1192   if (Lex.getCode() != tgtok::greater)
1193     return TokError("expected '>' at end of template argument list");
1194   Lex.Lex(); // eat the '>'.
1195   return false;
1196 }
1197
1198
1199 /// ParseBodyItem - Parse a single item at within the body of a def or class.
1200 ///
1201 ///   BodyItem ::= Declaration ';'
1202 ///   BodyItem ::= LET ID OptionalBitList '=' Value ';'
1203 bool TGParser::ParseBodyItem(Record *CurRec) {
1204   if (Lex.getCode() != tgtok::Let) {
1205     if (ParseDeclaration(CurRec, false).empty())
1206       return true;
1207
1208     if (Lex.getCode() != tgtok::semi)
1209       return TokError("expected ';' after declaration");
1210     Lex.Lex();
1211     return false;
1212   }
1213
1214   // LET ID OptionalRangeList '=' Value ';'
1215   if (Lex.Lex() != tgtok::Id)
1216     return TokError("expected field identifier after let");
1217
1218   TGLoc IdLoc = Lex.getLoc();
1219   std::string FieldName = Lex.getCurStrVal();
1220   Lex.Lex();  // eat the field name.
1221
1222   std::vector<unsigned> BitList;
1223   if (ParseOptionalBitList(BitList))
1224     return true;
1225   std::reverse(BitList.begin(), BitList.end());
1226
1227   if (Lex.getCode() != tgtok::equal)
1228     return TokError("expected '=' in let expression");
1229   Lex.Lex();  // eat the '='.
1230
1231   Init *Val = ParseValue(CurRec);
1232   if (Val == 0) return true;
1233
1234   if (Lex.getCode() != tgtok::semi)
1235     return TokError("expected ';' after let expression");
1236   Lex.Lex();
1237
1238   return SetValue(CurRec, IdLoc, FieldName, BitList, Val);
1239 }
1240
1241 /// ParseBody - Read the body of a class or def.  Return true on error, false on
1242 /// success.
1243 ///
1244 ///   Body     ::= ';'
1245 ///   Body     ::= '{' BodyList '}'
1246 ///   BodyList BodyItem*
1247 ///
1248 bool TGParser::ParseBody(Record *CurRec) {
1249   // If this is a null definition, just eat the semi and return.
1250   if (Lex.getCode() == tgtok::semi) {
1251     Lex.Lex();
1252     return false;
1253   }
1254
1255   if (Lex.getCode() != tgtok::l_brace)
1256     return TokError("Expected ';' or '{' to start body");
1257   // Eat the '{'.
1258   Lex.Lex();
1259
1260   while (Lex.getCode() != tgtok::r_brace)
1261     if (ParseBodyItem(CurRec))
1262       return true;
1263
1264   // Eat the '}'.
1265   Lex.Lex();
1266   return false;
1267 }
1268
1269 /// ParseObjectBody - Parse the body of a def or class.  This consists of an
1270 /// optional ClassList followed by a Body.  CurRec is the current def or class
1271 /// that is being parsed.
1272 ///
1273 ///   ObjectBody      ::= BaseClassList Body
1274 ///   BaseClassList   ::= /*empty*/
1275 ///   BaseClassList   ::= ':' BaseClassListNE
1276 ///   BaseClassListNE ::= SubClassRef (',' SubClassRef)*
1277 ///
1278 bool TGParser::ParseObjectBody(Record *CurRec) {
1279   // If there is a baseclass list, read it.
1280   if (Lex.getCode() == tgtok::colon) {
1281     Lex.Lex();
1282
1283     // Read all of the subclasses.
1284     SubClassReference SubClass = ParseSubClassReference(CurRec, false);
1285     while (1) {
1286       // Check for error.
1287       if (SubClass.Rec == 0) return true;
1288
1289       // Add it.
1290       if (AddSubClass(CurRec, SubClass))
1291         return true;
1292
1293       if (Lex.getCode() != tgtok::comma) break;
1294       Lex.Lex(); // eat ','.
1295       SubClass = ParseSubClassReference(CurRec, false);
1296     }
1297   }
1298
1299   // Process any variables on the let stack.
1300   for (unsigned i = 0, e = LetStack.size(); i != e; ++i)
1301     for (unsigned j = 0, e = LetStack[i].size(); j != e; ++j)
1302       if (SetValue(CurRec, LetStack[i][j].Loc, LetStack[i][j].Name,
1303                    LetStack[i][j].Bits, LetStack[i][j].Value))
1304         return true;
1305
1306   return ParseBody(CurRec);
1307 }
1308
1309
1310 /// ParseDef - Parse and return a top level or multiclass def, return the record
1311 /// corresponding to it.  This returns null on error.
1312 ///
1313 ///   DefInst ::= DEF ObjectName ObjectBody
1314 ///
1315 llvm::Record *TGParser::ParseDef(MultiClass *CurMultiClass) {
1316   TGLoc DefLoc = Lex.getLoc();
1317   assert(Lex.getCode() == tgtok::Def && "Unknown tok");
1318   Lex.Lex();  // Eat the 'def' token.
1319
1320   // Parse ObjectName and make a record for it.
1321   Record *CurRec = new Record(ParseObjectName(), DefLoc);
1322
1323   if (!CurMultiClass) {
1324     // Top-level def definition.
1325
1326     // Ensure redefinition doesn't happen.
1327     if (Records.getDef(CurRec->getName())) {
1328       Error(DefLoc, "def '" + CurRec->getName() + "' already defined");
1329       return 0;
1330     }
1331     Records.addDef(CurRec);
1332   } else {
1333     // Otherwise, a def inside a multiclass, add it to the multiclass.
1334     for (unsigned i = 0, e = CurMultiClass->DefPrototypes.size(); i != e; ++i)
1335       if (CurMultiClass->DefPrototypes[i]->getName() == CurRec->getName()) {
1336         Error(DefLoc, "def '" + CurRec->getName() +
1337               "' already defined in this multiclass!");
1338         return 0;
1339       }
1340     CurMultiClass->DefPrototypes.push_back(CurRec);
1341   }
1342
1343   if (ParseObjectBody(CurRec))
1344     return 0;
1345
1346   if (CurMultiClass == 0)  // Def's in multiclasses aren't really defs.
1347     CurRec->resolveReferences();
1348
1349   // If ObjectBody has template arguments, it's an error.
1350   assert(CurRec->getTemplateArgs().empty() && "How'd this get template args?");
1351   return CurRec;
1352 }
1353
1354
1355 /// ParseClass - Parse a tblgen class definition.
1356 ///
1357 ///   ClassInst ::= CLASS ID TemplateArgList? ObjectBody
1358 ///
1359 bool TGParser::ParseClass() {
1360   assert(Lex.getCode() == tgtok::Class && "Unexpected token!");
1361   Lex.Lex();
1362
1363   if (Lex.getCode() != tgtok::Id)
1364     return TokError("expected class name after 'class' keyword");
1365
1366   Record *CurRec = Records.getClass(Lex.getCurStrVal());
1367   if (CurRec) {
1368     // If the body was previously defined, this is an error.
1369     if (!CurRec->getValues().empty() ||
1370         !CurRec->getSuperClasses().empty() ||
1371         !CurRec->getTemplateArgs().empty())
1372       return TokError("Class '" + CurRec->getName() + "' already defined");
1373   } else {
1374     // If this is the first reference to this class, create and add it.
1375     CurRec = new Record(Lex.getCurStrVal(), Lex.getLoc());
1376     Records.addClass(CurRec);
1377   }
1378   Lex.Lex(); // eat the name.
1379
1380   // If there are template args, parse them.
1381   if (Lex.getCode() == tgtok::less)
1382     if (ParseTemplateArgList(CurRec))
1383       return true;
1384
1385   // Finally, parse the object body.
1386   return ParseObjectBody(CurRec);
1387 }
1388
1389 /// ParseLetList - Parse a non-empty list of assignment expressions into a list
1390 /// of LetRecords.
1391 ///
1392 ///   LetList ::= LetItem (',' LetItem)*
1393 ///   LetItem ::= ID OptionalRangeList '=' Value
1394 ///
1395 std::vector<LetRecord> TGParser::ParseLetList() {
1396   std::vector<LetRecord> Result;
1397
1398   while (1) {
1399     if (Lex.getCode() != tgtok::Id) {
1400       TokError("expected identifier in let definition");
1401       return std::vector<LetRecord>();
1402     }
1403     std::string Name = Lex.getCurStrVal();
1404     TGLoc NameLoc = Lex.getLoc();
1405     Lex.Lex();  // Eat the identifier.
1406
1407     // Check for an optional RangeList.
1408     std::vector<unsigned> Bits;
1409     if (ParseOptionalRangeList(Bits))
1410       return std::vector<LetRecord>();
1411     std::reverse(Bits.begin(), Bits.end());
1412
1413     if (Lex.getCode() != tgtok::equal) {
1414       TokError("expected '=' in let expression");
1415       return std::vector<LetRecord>();
1416     }
1417     Lex.Lex();  // eat the '='.
1418
1419     Init *Val = ParseValue(0);
1420     if (Val == 0) return std::vector<LetRecord>();
1421
1422     // Now that we have everything, add the record.
1423     Result.push_back(LetRecord(Name, Bits, Val, NameLoc));
1424
1425     if (Lex.getCode() != tgtok::comma)
1426       return Result;
1427     Lex.Lex();  // eat the comma.
1428   }
1429 }
1430
1431 /// ParseTopLevelLet - Parse a 'let' at top level.  This can be a couple of
1432 /// different related productions.
1433 ///
1434 ///   Object ::= LET LetList IN '{' ObjectList '}'
1435 ///   Object ::= LET LetList IN Object
1436 ///
1437 bool TGParser::ParseTopLevelLet() {
1438   assert(Lex.getCode() == tgtok::Let && "Unexpected token");
1439   Lex.Lex();
1440
1441   // Add this entry to the let stack.
1442   std::vector<LetRecord> LetInfo = ParseLetList();
1443   if (LetInfo.empty()) return true;
1444   LetStack.push_back(LetInfo);
1445
1446   if (Lex.getCode() != tgtok::In)
1447     return TokError("expected 'in' at end of top-level 'let'");
1448   Lex.Lex();
1449
1450   // If this is a scalar let, just handle it now
1451   if (Lex.getCode() != tgtok::l_brace) {
1452     // LET LetList IN Object
1453     if (ParseObject())
1454       return true;
1455   } else {   // Object ::= LETCommand '{' ObjectList '}'
1456     TGLoc BraceLoc = Lex.getLoc();
1457     // Otherwise, this is a group let.
1458     Lex.Lex();  // eat the '{'.
1459
1460     // Parse the object list.
1461     if (ParseObjectList())
1462       return true;
1463
1464     if (Lex.getCode() != tgtok::r_brace) {
1465       TokError("expected '}' at end of top level let command");
1466       return Error(BraceLoc, "to match this '{'");
1467     }
1468     Lex.Lex();
1469   }
1470
1471   // Outside this let scope, this let block is not active.
1472   LetStack.pop_back();
1473   return false;
1474 }
1475
1476 /// ParseMultiClassDef - Parse a def in a multiclass context.
1477 ///
1478 ///  MultiClassDef ::= DefInst
1479 ///
1480 bool TGParser::ParseMultiClassDef(MultiClass *CurMC) {
1481   if (Lex.getCode() != tgtok::Def)
1482     return TokError("expected 'def' in multiclass body");
1483
1484   Record *D = ParseDef(CurMC);
1485   if (D == 0) return true;
1486
1487   // Copy the template arguments for the multiclass into the def.
1488   const std::vector<std::string> &TArgs = CurMC->Rec.getTemplateArgs();
1489
1490   for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
1491     const RecordVal *RV = CurMC->Rec.getValue(TArgs[i]);
1492     assert(RV && "Template arg doesn't exist?");
1493     D->addValue(*RV);
1494   }
1495
1496   return false;
1497 }
1498
1499 /// ParseMultiClass - Parse a multiclass definition.
1500 ///
1501 ///  MultiClassInst ::= MULTICLASS ID TemplateArgList?
1502 ///                     ':' BaseMultiClassList '{' MultiClassDef+ '}'
1503 ///
1504 bool TGParser::ParseMultiClass() {
1505   assert(Lex.getCode() == tgtok::MultiClass && "Unexpected token");
1506   Lex.Lex();  // Eat the multiclass token.
1507
1508   if (Lex.getCode() != tgtok::Id)
1509     return TokError("expected identifier after multiclass for name");
1510   std::string Name = Lex.getCurStrVal();
1511
1512   if (MultiClasses.count(Name))
1513     return TokError("multiclass '" + Name + "' already defined");
1514
1515   CurMultiClass = MultiClasses[Name] = new MultiClass(Name, Lex.getLoc());
1516   Lex.Lex();  // Eat the identifier.
1517
1518   // If there are template args, parse them.
1519   if (Lex.getCode() == tgtok::less)
1520     if (ParseTemplateArgList(0))
1521       return true;
1522
1523   bool inherits = false;
1524
1525   // If there are submulticlasses, parse them.
1526   if (Lex.getCode() == tgtok::colon) {
1527     inherits = true;
1528
1529     Lex.Lex();
1530
1531     // Read all of the submulticlasses.
1532     SubMultiClassReference SubMultiClass =
1533       ParseSubMultiClassReference(CurMultiClass);
1534     while (1) {
1535       // Check for error.
1536       if (SubMultiClass.MC == 0) return true;
1537
1538       // Add it.
1539       if (AddSubMultiClass(CurMultiClass, SubMultiClass))
1540         return true;
1541
1542       if (Lex.getCode() != tgtok::comma) break;
1543       Lex.Lex(); // eat ','.
1544       SubMultiClass = ParseSubMultiClassReference(CurMultiClass);
1545     }
1546   }
1547
1548   if (Lex.getCode() != tgtok::l_brace) {
1549     if (!inherits)
1550       return TokError("expected '{' in multiclass definition");
1551     else
1552       if (Lex.getCode() != tgtok::semi)
1553         return TokError("expected ';' in multiclass definition");
1554       else
1555         Lex.Lex();  // eat the ';'.
1556   }
1557   else {
1558     if (Lex.Lex() == tgtok::r_brace)  // eat the '{'.
1559       return TokError("multiclass must contain at least one def");
1560
1561     while (Lex.getCode() != tgtok::r_brace)
1562       if (ParseMultiClassDef(CurMultiClass))
1563         return true;
1564
1565     Lex.Lex();  // eat the '}'.
1566   }
1567
1568   CurMultiClass = 0;
1569   return false;
1570 }
1571
1572 /// ParseDefm - Parse the instantiation of a multiclass.
1573 ///
1574 ///   DefMInst ::= DEFM ID ':' DefmSubClassRef ';'
1575 ///
1576 bool TGParser::ParseDefm() {
1577   assert(Lex.getCode() == tgtok::Defm && "Unexpected token!");
1578   if (Lex.Lex() != tgtok::Id)  // eat the defm.
1579     return TokError("expected identifier after defm");
1580
1581   TGLoc DefmPrefixLoc = Lex.getLoc();
1582   std::string DefmPrefix = Lex.getCurStrVal();
1583   if (Lex.Lex() != tgtok::colon)
1584     return TokError("expected ':' after defm identifier");
1585
1586   // eat the colon.
1587   Lex.Lex();
1588
1589   TGLoc SubClassLoc = Lex.getLoc();
1590   SubClassReference Ref = ParseSubClassReference(0, true);
1591
1592   while (1) {
1593     if (Ref.Rec == 0) return true;
1594
1595     // To instantiate a multiclass, we need to first get the multiclass, then
1596     // instantiate each def contained in the multiclass with the SubClassRef
1597     // template parameters.
1598     MultiClass *MC = MultiClasses[Ref.Rec->getName()];
1599     assert(MC && "Didn't lookup multiclass correctly?");
1600     std::vector<Init*> &TemplateVals = Ref.TemplateArgs;
1601
1602     // Verify that the correct number of template arguments were specified.
1603     const std::vector<std::string> &TArgs = MC->Rec.getTemplateArgs();
1604     if (TArgs.size() < TemplateVals.size())
1605       return Error(SubClassLoc,
1606                    "more template args specified than multiclass expects");
1607
1608     // Loop over all the def's in the multiclass, instantiating each one.
1609     for (unsigned i = 0, e = MC->DefPrototypes.size(); i != e; ++i) {
1610       Record *DefProto = MC->DefPrototypes[i];
1611
1612       // Add the suffix to the defm name to get the new name.
1613       Record *CurRec = new Record(DefmPrefix + DefProto->getName(),
1614                                   DefmPrefixLoc);
1615
1616       SubClassReference Ref;
1617       Ref.RefLoc = DefmPrefixLoc;
1618       Ref.Rec = DefProto;
1619       AddSubClass(CurRec, Ref);
1620
1621       // Loop over all of the template arguments, setting them to the specified
1622       // value or leaving them as the default if necessary.
1623       for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
1624         // Check if a value is specified for this temp-arg.
1625         if (i < TemplateVals.size()) {
1626           // Set it now.
1627           if (SetValue(CurRec, DefmPrefixLoc, TArgs[i], std::vector<unsigned>(),
1628                        TemplateVals[i]))
1629             return true;
1630
1631           // Resolve it next.
1632           CurRec->resolveReferencesTo(CurRec->getValue(TArgs[i]));
1633
1634           // Now remove it.
1635           CurRec->removeValue(TArgs[i]);
1636
1637         } else if (!CurRec->getValue(TArgs[i])->getValue()->isComplete()) {
1638           return Error(SubClassLoc,
1639                        "value not specified for template argument #"+
1640                        utostr(i) + " (" + TArgs[i] + ") of multiclassclass '" +
1641                        MC->Rec.getName() + "'");
1642         }
1643       }
1644
1645       // If the mdef is inside a 'let' expression, add to each def.
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             Error(DefmPrefixLoc, "when instantiating this defm");
1651             return true;
1652           }
1653
1654       // Ensure redefinition doesn't happen.
1655       if (Records.getDef(CurRec->getName()))
1656         return Error(DefmPrefixLoc, "def '" + CurRec->getName() +
1657                      "' already defined, instantiating defm with subdef '" +
1658                      DefProto->getName() + "'");
1659       Records.addDef(CurRec);
1660       CurRec->resolveReferences();
1661     }
1662
1663     if (Lex.getCode() != tgtok::comma) break;
1664     Lex.Lex(); // eat ','.
1665
1666     SubClassLoc = Lex.getLoc();
1667     Ref = ParseSubClassReference(0, true);
1668   }
1669
1670   if (Lex.getCode() != tgtok::semi)
1671     return TokError("expected ';' at end of defm");
1672   Lex.Lex();
1673
1674   return false;
1675 }
1676
1677 /// ParseObject
1678 ///   Object ::= ClassInst
1679 ///   Object ::= DefInst
1680 ///   Object ::= MultiClassInst
1681 ///   Object ::= DefMInst
1682 ///   Object ::= LETCommand '{' ObjectList '}'
1683 ///   Object ::= LETCommand Object
1684 bool TGParser::ParseObject() {
1685   switch (Lex.getCode()) {
1686   default: assert(0 && "This is not an object");
1687   case tgtok::Let:   return ParseTopLevelLet();
1688   case tgtok::Def:   return ParseDef(0) == 0;
1689   case tgtok::Defm:  return ParseDefm();
1690   case tgtok::Class: return ParseClass();
1691   case tgtok::MultiClass: return ParseMultiClass();
1692   }
1693 }
1694
1695 /// ParseObjectList
1696 ///   ObjectList :== Object*
1697 bool TGParser::ParseObjectList() {
1698   while (isObjectStart(Lex.getCode())) {
1699     if (ParseObject())
1700       return true;
1701   }
1702   return false;
1703 }
1704
1705
1706 bool TGParser::ParseFile() {
1707   Lex.Lex(); // Prime the lexer.
1708   if (ParseObjectList()) return true;
1709
1710   // If we have unread input at the end of the file, report it.
1711   if (Lex.getCode() == tgtok::Eof)
1712     return false;
1713
1714   return TokError("Unexpected input at top level");
1715 }
1716