llvm/lib/TableGen/Record.cpp

   1 //===- Record.cpp - Record implementation ---------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Implement the tablegen record classes.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/ADT/ArrayRef.h"
  14 #include "llvm/ADT/DenseMap.h"
  15 #include "llvm/ADT/FoldingSet.h"
  16 #include "llvm/ADT/SmallString.h"
  17 #include "llvm/ADT/SmallVector.h"
  18 #include "llvm/ADT/Statistic.h"
  19 #include "llvm/ADT/StringExtras.h"
  20 #include "llvm/ADT/StringMap.h"
  21 #include "llvm/ADT/StringRef.h"
  22 #include "llvm/ADT/StringSet.h"
  23 #include "llvm/Config/llvm-config.h"
  24 #include "llvm/Support/Allocator.h"
  25 #include "llvm/Support/Casting.h"
  26 #include "llvm/Support/Compiler.h"
  27 #include "llvm/Support/ErrorHandling.h"
  28 #include "llvm/Support/SMLoc.h"
  29 #include "llvm/Support/raw_ostream.h"
  30 #include "llvm/TableGen/Error.h"
  31 #include "llvm/TableGen/Record.h"
  32 #include <cassert>
  33 #include <cstdint>
  34 #include <memory>
  35 #include <map>
  36 #include <string>
  37 #include <utility>
  38 #include <vector>
  39
  40 using namespace llvm;
  41
  42 #define DEBUG_TYPE "tblgen-records"
  43
  44 static BumpPtrAllocator Allocator;
  45
  46 STATISTIC(CodeInitsConstructed,
  47           "The total number of unique CodeInits constructed");
  48
  49 //===----------------------------------------------------------------------===//
  50 //    Type implementations
  51 //===----------------------------------------------------------------------===//
  52
  53 BitRecTy BitRecTy::Shared;
  54 CodeRecTy CodeRecTy::Shared;
  55 IntRecTy IntRecTy::Shared;
  56 StringRecTy StringRecTy::Shared;
  57 DagRecTy DagRecTy::Shared;
  58
  59 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  60 LLVM_DUMP_METHOD void RecTy::dump() const { print(errs()); }
  61 #endif
  62
  63 ListRecTy *RecTy::getListTy() {
  64   if (!ListTy)
  65     ListTy = new(Allocator) ListRecTy(this);
  66   return ListTy;
  67 }
  68
  69 bool RecTy::typeIsConvertibleTo(const RecTy *RHS) const {
  70   assert(RHS && "NULL pointer");
  71   return Kind == RHS->getRecTyKind();
  72 }
  73
  74 bool RecTy::typeIsA(const RecTy *RHS) const { return this == RHS; }
  75
  76 bool BitRecTy::typeIsConvertibleTo(const RecTy *RHS) const{
  77   if (RecTy::typeIsConvertibleTo(RHS) || RHS->getRecTyKind() == IntRecTyKind)
  78     return true;
  79   if (const BitsRecTy *BitsTy = dyn_cast<BitsRecTy>(RHS))
  80     return BitsTy->getNumBits() == 1;
  81   return false;
  82 }
  83
  84 BitsRecTy *BitsRecTy::get(unsigned Sz) {
  85   static std::vector<BitsRecTy*> Shared;
  86   if (Sz >= Shared.size())
  87     Shared.resize(Sz + 1);
  88   BitsRecTy *&Ty = Shared[Sz];
  89   if (!Ty)
  90     Ty = new(Allocator) BitsRecTy(Sz);
  91   return Ty;
  92 }
  93
  94 std::string BitsRecTy::getAsString() const {
  95   return "bits<" + utostr(Size) + ">";
  96 }
  97
  98 bool BitsRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
  99   if (RecTy::typeIsConvertibleTo(RHS)) //argument and the sender are same type
 100     return cast<BitsRecTy>(RHS)->Size == Size;
 101   RecTyKind kind = RHS->getRecTyKind();
 102   return (kind == BitRecTyKind && Size == 1) || (kind == IntRecTyKind);
 103 }
 104
 105 bool BitsRecTy::typeIsA(const RecTy *RHS) const {
 106   if (const BitsRecTy *RHSb = dyn_cast<BitsRecTy>(RHS))
 107     return RHSb->Size == Size;
 108   return false;
 109 }
 110
 111 bool IntRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
 112   RecTyKind kind = RHS->getRecTyKind();
 113   return kind==BitRecTyKind || kind==BitsRecTyKind || kind==IntRecTyKind;
 114 }
 115
 116 bool CodeRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
 117   RecTyKind Kind = RHS->getRecTyKind();
 118   return Kind == CodeRecTyKind || Kind == StringRecTyKind;
 119 }
 120
 121 std::string StringRecTy::getAsString() const {
 122   return "string";
 123 }
 124
 125 bool StringRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
 126   RecTyKind Kind = RHS->getRecTyKind();
 127   return Kind == StringRecTyKind || Kind == CodeRecTyKind;
 128 }
 129
 130 std::string ListRecTy::getAsString() const {
 131   return "list<" + Ty->getAsString() + ">";
 132 }
 133
 134 bool ListRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
 135   if (const auto *ListTy = dyn_cast<ListRecTy>(RHS))
 136     return Ty->typeIsConvertibleTo(ListTy->getElementType());
 137   return false;
 138 }
 139
 140 bool ListRecTy::typeIsA(const RecTy *RHS) const {
 141   if (const ListRecTy *RHSl = dyn_cast<ListRecTy>(RHS))
 142     return getElementType()->typeIsA(RHSl->getElementType());
 143   return false;
 144 }
 145
 146 std::string DagRecTy::getAsString() const {
 147   return "dag";
 148 }
 149
 150 static void ProfileRecordRecTy(FoldingSetNodeID &ID,
 151                                ArrayRef<Record *> Classes) {
 152   ID.AddInteger(Classes.size());
 153   for (Record *R : Classes)
 154     ID.AddPointer(R);
 155 }
 156
 157 RecordRecTy *RecordRecTy::get(ArrayRef<Record *> UnsortedClasses) {
 158   if (UnsortedClasses.empty()) {
 159     static RecordRecTy AnyRecord(0);
 160     return &AnyRecord;
 161   }
 162
 163   FoldingSet<RecordRecTy> &ThePool =
 164       UnsortedClasses[0]->getRecords().RecordTypePool;
 165
 166   SmallVector<Record *, 4> Classes(UnsortedClasses.begin(),
 167                                    UnsortedClasses.end());
 168   llvm::sort(Classes, [](Record *LHS, Record *RHS) {
 169     return LHS->getNameInitAsString() < RHS->getNameInitAsString();
 170   });
 171
 172   FoldingSetNodeID ID;
 173   ProfileRecordRecTy(ID, Classes);
 174
 175   void *IP = nullptr;
 176   if (RecordRecTy *Ty = ThePool.FindNodeOrInsertPos(ID, IP))
 177     return Ty;
 178
 179 #ifndef NDEBUG
 180   // Check for redundancy.
 181   for (unsigned i = 0; i < Classes.size(); ++i) {
 182     for (unsigned j = 0; j < Classes.size(); ++j) {
 183       assert(i == j || !Classes[i]->isSubClassOf(Classes[j]));
 184     }
 185     assert(&Classes[0]->getRecords() == &Classes[i]->getRecords());
 186   }
 187 #endif
 188
 189   void *Mem = Allocator.Allocate(totalSizeToAlloc<Record *>(Classes.size()),
 190                                  alignof(RecordRecTy));
 191   RecordRecTy *Ty = new(Mem) RecordRecTy(Classes.size());
 192   std::uninitialized_copy(Classes.begin(), Classes.end(),
 193                           Ty->getTrailingObjects<Record *>());
 194   ThePool.InsertNode(Ty, IP);
 195   return Ty;
 196 }
 197
 198 void RecordRecTy::Profile(FoldingSetNodeID &ID) const {
 199   ProfileRecordRecTy(ID, getClasses());
 200 }
 201
 202 std::string RecordRecTy::getAsString() const {
 203   if (NumClasses == 1)
 204     return getClasses()[0]->getNameInitAsString();
 205
 206   std::string Str = "{";
 207   bool First = true;
 208   for (Record *R : getClasses()) {
 209     if (!First)
 210       Str += ", ";
 211     First = false;
 212     Str += R->getNameInitAsString();
 213   }
 214   Str += "}";
 215   return Str;
 216 }
 217
 218 bool RecordRecTy::isSubClassOf(Record *Class) const {
 219   return llvm::any_of(getClasses(), [Class](Record *MySuperClass) {
 220                                       return MySuperClass == Class ||
 221                                              MySuperClass->isSubClassOf(Class);
 222                                     });
 223 }
 224
 225 bool RecordRecTy::typeIsConvertibleTo(const RecTy *RHS) const {
 226   if (this == RHS)
 227     return true;
 228
 229   const RecordRecTy *RTy = dyn_cast<RecordRecTy>(RHS);
 230   if (!RTy)
 231     return false;
 232
 233   return llvm::all_of(RTy->getClasses(), [this](Record *TargetClass) {
 234                                            return isSubClassOf(TargetClass);
 235                                          });
 236 }
 237
 238 bool RecordRecTy::typeIsA(const RecTy *RHS) const {
 239   return typeIsConvertibleTo(RHS);
 240 }
 241
 242 static RecordRecTy *resolveRecordTypes(RecordRecTy *T1, RecordRecTy *T2) {
 243   SmallVector<Record *, 4> CommonSuperClasses;
 244   SmallVector<Record *, 4> Stack;
 245
 246   Stack.insert(Stack.end(), T1->classes_begin(), T1->classes_end());
 247
 248   while (!Stack.empty()) {
 249     Record *R = Stack.back();
 250     Stack.pop_back();
 251
 252     if (T2->isSubClassOf(R)) {
 253       CommonSuperClasses.push_back(R);
 254     } else {
 255       R->getDirectSuperClasses(Stack);
 256     }
 257   }
 258
 259   return RecordRecTy::get(CommonSuperClasses);
 260 }
 261
 262 RecTy *llvm::resolveTypes(RecTy *T1, RecTy *T2) {
 263   if (T1 == T2)
 264     return T1;
 265
 266   if (RecordRecTy *RecTy1 = dyn_cast<RecordRecTy>(T1)) {
 267     if (RecordRecTy *RecTy2 = dyn_cast<RecordRecTy>(T2))
 268       return resolveRecordTypes(RecTy1, RecTy2);
 269   }
 270
 271   if (T1->typeIsConvertibleTo(T2))
 272     return T2;
 273   if (T2->typeIsConvertibleTo(T1))
 274     return T1;
 275
 276   if (ListRecTy *ListTy1 = dyn_cast<ListRecTy>(T1)) {
 277     if (ListRecTy *ListTy2 = dyn_cast<ListRecTy>(T2)) {
 278       RecTy* NewType = resolveTypes(ListTy1->getElementType(),
 279                                     ListTy2->getElementType());
 280       if (NewType)
 281         return NewType->getListTy();
 282     }
 283   }
 284
 285   return nullptr;
 286 }
 287
 288 //===----------------------------------------------------------------------===//
 289 //    Initializer implementations
 290 //===----------------------------------------------------------------------===//
 291
 292 void Init::anchor() {}
 293
 294 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 295 LLVM_DUMP_METHOD void Init::dump() const { return print(errs()); }
 296 #endif
 297
 298 UnsetInit *UnsetInit::get() {
 299   static UnsetInit TheInit;
 300   return &TheInit;
 301 }
 302
 303 Init *UnsetInit::getCastTo(RecTy *Ty) const {
 304   return const_cast<UnsetInit *>(this);
 305 }
 306
 307 Init *UnsetInit::convertInitializerTo(RecTy *Ty) const {
 308   return const_cast<UnsetInit *>(this);
 309 }
 310
 311 BitInit *BitInit::get(bool V) {
 312   static BitInit True(true);
 313   static BitInit False(false);
 314
 315   return V ? &True : &False;
 316 }
 317
 318 Init *BitInit::convertInitializerTo(RecTy *Ty) const {
 319   if (isa<BitRecTy>(Ty))
 320     return const_cast<BitInit *>(this);
 321
 322   if (isa<IntRecTy>(Ty))
 323     return IntInit::get(getValue());
 324
 325   if (auto *BRT = dyn_cast<BitsRecTy>(Ty)) {
 326     // Can only convert single bit.
 327     if (BRT->getNumBits() == 1)
 328       return BitsInit::get(const_cast<BitInit *>(this));
 329   }
 330
 331   return nullptr;
 332 }
 333
 334 static void
 335 ProfileBitsInit(FoldingSetNodeID &ID, ArrayRef<Init *> Range) {
 336   ID.AddInteger(Range.size());
 337
 338   for (Init *I : Range)
 339     ID.AddPointer(I);
 340 }
 341
 342 BitsInit *BitsInit::get(ArrayRef<Init *> Range) {
 343   static FoldingSet<BitsInit> ThePool;
 344
 345   FoldingSetNodeID ID;
 346   ProfileBitsInit(ID, Range);
 347
 348   void *IP = nullptr;
 349   if (BitsInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
 350     return I;
 351
 352   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(Range.size()),
 353                                  alignof(BitsInit));
 354   BitsInit *I = new(Mem) BitsInit(Range.size());
 355   std::uninitialized_copy(Range.begin(), Range.end(),
 356                           I->getTrailingObjects<Init *>());
 357   ThePool.InsertNode(I, IP);
 358   return I;
 359 }
 360
 361 void BitsInit::Profile(FoldingSetNodeID &ID) const {
 362   ProfileBitsInit(ID, makeArrayRef(getTrailingObjects<Init *>(), NumBits));
 363 }
 364
 365 Init *BitsInit::convertInitializerTo(RecTy *Ty) const {
 366   if (isa<BitRecTy>(Ty)) {
 367     if (getNumBits() != 1) return nullptr; // Only accept if just one bit!
 368     return getBit(0);
 369   }
 370
 371   if (auto *BRT = dyn_cast<BitsRecTy>(Ty)) {
 372     // If the number of bits is right, return it.  Otherwise we need to expand
 373     // or truncate.
 374     if (getNumBits() != BRT->getNumBits()) return nullptr;
 375     return const_cast<BitsInit *>(this);
 376   }
 377
 378   if (isa<IntRecTy>(Ty)) {
 379     int64_t Result = 0;
 380     for (unsigned i = 0, e = getNumBits(); i != e; ++i)
 381       if (auto *Bit = dyn_cast<BitInit>(getBit(i)))
 382         Result |= static_cast<int64_t>(Bit->getValue()) << i;
 383       else
 384         return nullptr;
 385     return IntInit::get(Result);
 386   }
 387
 388   return nullptr;
 389 }
 390
 391 Init *
 392 BitsInit::convertInitializerBitRange(ArrayRef<unsigned> Bits) const {
 393   SmallVector<Init *, 16> NewBits(Bits.size());
 394
 395   for (unsigned i = 0, e = Bits.size(); i != e; ++i) {
 396     if (Bits[i] >= getNumBits())
 397       return nullptr;
 398     NewBits[i] = getBit(Bits[i]);
 399   }
 400   return BitsInit::get(NewBits);
 401 }
 402
 403 bool BitsInit::isConcrete() const {
 404   for (unsigned i = 0, e = getNumBits(); i != e; ++i) {
 405     if (!getBit(i)->isConcrete())
 406       return false;
 407   }
 408   return true;
 409 }
 410
 411 std::string BitsInit::getAsString() const {
 412   std::string Result = "{ ";
 413   for (unsigned i = 0, e = getNumBits(); i != e; ++i) {
 414     if (i) Result += ", ";
 415     if (Init *Bit = getBit(e-i-1))
 416       Result += Bit->getAsString();
 417     else
 418       Result += "*";
 419   }
 420   return Result + " }";
 421 }
 422
 423 // resolveReferences - If there are any field references that refer to fields
 424 // that have been filled in, we can propagate the values now.
 425 Init *BitsInit::resolveReferences(Resolver &R) const {
 426   bool Changed = false;
 427   SmallVector<Init *, 16> NewBits(getNumBits());
 428
 429   Init *CachedBitVarRef = nullptr;
 430   Init *CachedBitVarResolved = nullptr;
 431
 432   for (unsigned i = 0, e = getNumBits(); i != e; ++i) {
 433     Init *CurBit = getBit(i);
 434     Init *NewBit = CurBit;
 435
 436     if (VarBitInit *CurBitVar = dyn_cast<VarBitInit>(CurBit)) {
 437       if (CurBitVar->getBitVar() != CachedBitVarRef) {
 438         CachedBitVarRef = CurBitVar->getBitVar();
 439         CachedBitVarResolved = CachedBitVarRef->resolveReferences(R);
 440       }
 441       assert(CachedBitVarResolved && "Unresolved bitvar reference");
 442       NewBit = CachedBitVarResolved->getBit(CurBitVar->getBitNum());
 443     } else {
 444       // getBit(0) implicitly converts int and bits<1> values to bit.
 445       NewBit = CurBit->resolveReferences(R)->getBit(0);
 446     }
 447
 448     if (isa<UnsetInit>(NewBit) && R.keepUnsetBits())
 449       NewBit = CurBit;
 450     NewBits[i] = NewBit;
 451     Changed |= CurBit != NewBit;
 452   }
 453
 454   if (Changed)
 455     return BitsInit::get(NewBits);
 456
 457   return const_cast<BitsInit *>(this);
 458 }
 459
 460 IntInit *IntInit::get(int64_t V) {
 461   static std::map<int64_t, IntInit*> ThePool;
 462
 463   IntInit *&I = ThePool[V];
 464   if (!I) I = new(Allocator) IntInit(V);
 465   return I;
 466 }
 467
 468 std::string IntInit::getAsString() const {
 469   return itostr(Value);
 470 }
 471
 472 static bool canFitInBitfield(int64_t Value, unsigned NumBits) {
 473   // For example, with NumBits == 4, we permit Values from [-7 .. 15].
 474   return (NumBits >= sizeof(Value) * 8) ||
 475          (Value >> NumBits == 0) || (Value >> (NumBits-1) == -1);
 476 }
 477
 478 Init *IntInit::convertInitializerTo(RecTy *Ty) const {
 479   if (isa<IntRecTy>(Ty))
 480     return const_cast<IntInit *>(this);
 481
 482   if (isa<BitRecTy>(Ty)) {
 483     int64_t Val = getValue();
 484     if (Val != 0 && Val != 1) return nullptr;  // Only accept 0 or 1 for a bit!
 485     return BitInit::get(Val != 0);
 486   }
 487
 488   if (auto *BRT = dyn_cast<BitsRecTy>(Ty)) {
 489     int64_t Value = getValue();
 490     // Make sure this bitfield is large enough to hold the integer value.
 491     if (!canFitInBitfield(Value, BRT->getNumBits()))
 492       return nullptr;
 493
 494     SmallVector<Init *, 16> NewBits(BRT->getNumBits());
 495     for (unsigned i = 0; i != BRT->getNumBits(); ++i)
 496       NewBits[i] = BitInit::get(Value & ((i < 64) ? (1LL << i) : 0));
 497
 498     return BitsInit::get(NewBits);
 499   }
 500
 501   return nullptr;
 502 }
 503
 504 Init *
 505 IntInit::convertInitializerBitRange(ArrayRef<unsigned> Bits) const {
 506   SmallVector<Init *, 16> NewBits(Bits.size());
 507
 508   for (unsigned i = 0, e = Bits.size(); i != e; ++i) {
 509     if (Bits[i] >= 64)
 510       return nullptr;
 511
 512     NewBits[i] = BitInit::get(Value & (INT64_C(1) << Bits[i]));
 513   }
 514   return BitsInit::get(NewBits);
 515 }
 516
 517 CodeInit *CodeInit::get(StringRef V, const SMLoc &Loc) {
 518   static StringSet<BumpPtrAllocator &> ThePool(Allocator);
 519
 520   CodeInitsConstructed++;
 521
 522   // Unlike StringMap, StringSet doesn't accept empty keys.
 523   if (V.empty())
 524     return new (Allocator) CodeInit("", Loc);
 525
 526   // Location tracking prevents us from de-duping CodeInits as we're never
 527   // called with the same string and same location twice. However, we can at
 528   // least de-dupe the strings for a modest saving.
 529   auto &Entry = *ThePool.insert(V).first;
 530   return new(Allocator) CodeInit(Entry.getKey(), Loc);
 531 }
 532
 533 StringInit *StringInit::get(StringRef V) {
 534   static StringMap<StringInit*, BumpPtrAllocator &> ThePool(Allocator);
 535
 536   auto &Entry = *ThePool.insert(std::make_pair(V, nullptr)).first;
 537   if (!Entry.second)
 538     Entry.second = new(Allocator) StringInit(Entry.getKey());
 539   return Entry.second;
 540 }
 541
 542 Init *StringInit::convertInitializerTo(RecTy *Ty) const {
 543   if (isa<StringRecTy>(Ty))
 544     return const_cast<StringInit *>(this);
 545   if (isa<CodeRecTy>(Ty))
 546     return CodeInit::get(getValue(), SMLoc());
 547
 548   return nullptr;
 549 }
 550
 551 Init *CodeInit::convertInitializerTo(RecTy *Ty) const {
 552   if (isa<CodeRecTy>(Ty))
 553     return const_cast<CodeInit *>(this);
 554   if (isa<StringRecTy>(Ty))
 555     return StringInit::get(getValue());
 556
 557   return nullptr;
 558 }
 559
 560 static void ProfileListInit(FoldingSetNodeID &ID,
 561                             ArrayRef<Init *> Range,
 562                             RecTy *EltTy) {
 563   ID.AddInteger(Range.size());
 564   ID.AddPointer(EltTy);
 565
 566   for (Init *I : Range)
 567     ID.AddPointer(I);
 568 }
 569
 570 ListInit *ListInit::get(ArrayRef<Init *> Range, RecTy *EltTy) {
 571   static FoldingSet<ListInit> ThePool;
 572
 573   FoldingSetNodeID ID;
 574   ProfileListInit(ID, Range, EltTy);
 575
 576   void *IP = nullptr;
 577   if (ListInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
 578     return I;
 579
 580   assert(Range.empty() || !isa<TypedInit>(Range[0]) ||
 581          cast<TypedInit>(Range[0])->getType()->typeIsConvertibleTo(EltTy));
 582
 583   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(Range.size()),
 584                                  alignof(ListInit));
 585   ListInit *I = new(Mem) ListInit(Range.size(), EltTy);
 586   std::uninitialized_copy(Range.begin(), Range.end(),
 587                           I->getTrailingObjects<Init *>());
 588   ThePool.InsertNode(I, IP);
 589   return I;
 590 }
 591
 592 void ListInit::Profile(FoldingSetNodeID &ID) const {
 593   RecTy *EltTy = cast<ListRecTy>(getType())->getElementType();
 594
 595   ProfileListInit(ID, getValues(), EltTy);
 596 }
 597
 598 Init *ListInit::convertInitializerTo(RecTy *Ty) const {
 599   if (getType() == Ty)
 600     return const_cast<ListInit*>(this);
 601
 602   if (auto *LRT = dyn_cast<ListRecTy>(Ty)) {
 603     SmallVector<Init*, 8> Elements;
 604     Elements.reserve(getValues().size());
 605
 606     // Verify that all of the elements of the list are subclasses of the
 607     // appropriate class!
 608     bool Changed = false;
 609     RecTy *ElementType = LRT->getElementType();
 610     for (Init *I : getValues())
 611       if (Init *CI = I->convertInitializerTo(ElementType)) {
 612         Elements.push_back(CI);
 613         if (CI != I)
 614           Changed = true;
 615       } else
 616         return nullptr;
 617
 618     if (!Changed)
 619       return const_cast<ListInit*>(this);
 620     return ListInit::get(Elements, ElementType);
 621   }
 622
 623   return nullptr;
 624 }
 625
 626 Init *ListInit::convertInitListSlice(ArrayRef<unsigned> Elements) const {
 627   SmallVector<Init*, 8> Vals;
 628   Vals.reserve(Elements.size());
 629   for (unsigned Element : Elements) {
 630     if (Element >= size())
 631       return nullptr;
 632     Vals.push_back(getElement(Element));
 633   }
 634   return ListInit::get(Vals, getElementType());
 635 }
 636
 637 Record *ListInit::getElementAsRecord(unsigned i) const {
 638   assert(i < NumValues && "List element index out of range!");
 639   DefInit *DI = dyn_cast<DefInit>(getElement(i));
 640   if (!DI)
 641     PrintFatalError("Expected record in list!");
 642   return DI->getDef();
 643 }
 644
 645 Init *ListInit::resolveReferences(Resolver &R) const {
 646   SmallVector<Init*, 8> Resolved;
 647   Resolved.reserve(size());
 648   bool Changed = false;
 649
 650   for (Init *CurElt : getValues()) {
 651     Init *E = CurElt->resolveReferences(R);
 652     Changed |= E != CurElt;
 653     Resolved.push_back(E);
 654   }
 655
 656   if (Changed)
 657     return ListInit::get(Resolved, getElementType());
 658   return const_cast<ListInit *>(this);
 659 }
 660
 661 bool ListInit::isConcrete() const {
 662   for (Init *Element : *this) {
 663     if (!Element->isConcrete())
 664       return false;
 665   }
 666   return true;
 667 }
 668
 669 std::string ListInit::getAsString() const {
 670   std::string Result = "[";
 671   const char *sep = "";
 672   for (Init *Element : *this) {
 673     Result += sep;
 674     sep = ", ";
 675     Result += Element->getAsString();
 676   }
 677   return Result + "]";
 678 }
 679
 680 Init *OpInit::getBit(unsigned Bit) const {
 681   if (getType() == BitRecTy::get())
 682     return const_cast<OpInit*>(this);
 683   return VarBitInit::get(const_cast<OpInit*>(this), Bit);
 684 }
 685
 686 static void
 687 ProfileUnOpInit(FoldingSetNodeID &ID, unsigned Opcode, Init *Op, RecTy *Type) {
 688   ID.AddInteger(Opcode);
 689   ID.AddPointer(Op);
 690   ID.AddPointer(Type);
 691 }
 692
 693 UnOpInit *UnOpInit::get(UnaryOp Opc, Init *LHS, RecTy *Type) {
 694   static FoldingSet<UnOpInit> ThePool;
 695
 696   FoldingSetNodeID ID;
 697   ProfileUnOpInit(ID, Opc, LHS, Type);
 698
 699   void *IP = nullptr;
 700   if (UnOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
 701     return I;
 702
 703   UnOpInit *I = new(Allocator) UnOpInit(Opc, LHS, Type);
 704   ThePool.InsertNode(I, IP);
 705   return I;
 706 }
 707
 708 void UnOpInit::Profile(FoldingSetNodeID &ID) const {
 709   ProfileUnOpInit(ID, getOpcode(), getOperand(), getType());
 710 }
 711
 712 Init *UnOpInit::Fold(Record *CurRec, bool IsFinal) const {
 713   switch (getOpcode()) {
 714   case CAST:
 715     if (isa<StringRecTy>(getType())) {
 716       if (StringInit *LHSs = dyn_cast<StringInit>(LHS))
 717         return LHSs;
 718
 719       if (DefInit *LHSd = dyn_cast<DefInit>(LHS))
 720         return StringInit::get(LHSd->getAsString());
 721
 722       if (IntInit *LHSi = dyn_cast<IntInit>(LHS))
 723         return StringInit::get(LHSi->getAsString());
 724     } else if (isa<RecordRecTy>(getType())) {
 725       if (StringInit *Name = dyn_cast<StringInit>(LHS)) {
 726         if (!CurRec && !IsFinal)
 727           break;
 728         assert(CurRec && "NULL pointer");
 729         Record *D;
 730
 731         // Self-references are allowed, but their resolution is delayed until
 732         // the final resolve to ensure that we get the correct type for them.
 733         if (Name == CurRec->getNameInit()) {
 734           if (!IsFinal)
 735             break;
 736           D = CurRec;
 737         } else {
 738           D = CurRec->getRecords().getDef(Name->getValue());
 739           if (!D) {
 740             if (IsFinal)
 741               PrintFatalError(CurRec->getLoc(),
 742                               Twine("Undefined reference to record: '") +
 743                               Name->getValue() + "'\n");
 744             break;
 745           }
 746         }
 747
 748         DefInit *DI = DefInit::get(D);
 749         if (!DI->getType()->typeIsA(getType())) {
 750           PrintFatalError(CurRec->getLoc(),
 751                           Twine("Expected type '") +
 752                           getType()->getAsString() + "', got '" +
 753                           DI->getType()->getAsString() + "' in: " +
 754                           getAsString() + "\n");
 755         }
 756         return DI;
 757       }
 758     }
 759
 760     if (Init *NewInit = LHS->convertInitializerTo(getType()))
 761       return NewInit;
 762     break;
 763
 764   case HEAD:
 765     if (ListInit *LHSl = dyn_cast<ListInit>(LHS)) {
 766       assert(!LHSl->empty() && "Empty list in head");
 767       return LHSl->getElement(0);
 768     }
 769     break;
 770
 771   case TAIL:
 772     if (ListInit *LHSl = dyn_cast<ListInit>(LHS)) {
 773       assert(!LHSl->empty() && "Empty list in tail");
 774       // Note the +1.  We can't just pass the result of getValues()
 775       // directly.
 776       return ListInit::get(LHSl->getValues().slice(1), LHSl->getElementType());
 777     }
 778     break;
 779
 780   case SIZE:
 781     if (ListInit *LHSl = dyn_cast<ListInit>(LHS))
 782       return IntInit::get(LHSl->size());
 783     break;
 784
 785   case EMPTY:
 786     if (ListInit *LHSl = dyn_cast<ListInit>(LHS))
 787       return IntInit::get(LHSl->empty());
 788     if (StringInit *LHSs = dyn_cast<StringInit>(LHS))
 789       return IntInit::get(LHSs->getValue().empty());
 790     break;
 791
 792   case GETOP:
 793     if (DagInit *Dag = dyn_cast<DagInit>(LHS)) {
 794       DefInit *DI = DefInit::get(Dag->getOperatorAsDef({}));
 795       if (!DI->getType()->typeIsA(getType())) {
 796         PrintFatalError(CurRec->getLoc(),
 797                         Twine("Expected type '") +
 798                         getType()->getAsString() + "', got '" +
 799                         DI->getType()->getAsString() + "' in: " +
 800                         getAsString() + "\n");
 801       } else {
 802         return DI;
 803       }
 804     }
 805     break;
 806   }
 807   return const_cast<UnOpInit *>(this);
 808 }
 809
 810 Init *UnOpInit::resolveReferences(Resolver &R) const {
 811   Init *lhs = LHS->resolveReferences(R);
 812
 813   if (LHS != lhs || (R.isFinal() && getOpcode() == CAST))
 814     return (UnOpInit::get(getOpcode(), lhs, getType()))
 815         ->Fold(R.getCurrentRecord(), R.isFinal());
 816   return const_cast<UnOpInit *>(this);
 817 }
 818
 819 std::string UnOpInit::getAsString() const {
 820   std::string Result;
 821   switch (getOpcode()) {
 822   case CAST: Result = "!cast<" + getType()->getAsString() + ">"; break;
 823   case HEAD: Result = "!head"; break;
 824   case TAIL: Result = "!tail"; break;
 825   case SIZE: Result = "!size"; break;
 826   case EMPTY: Result = "!empty"; break;
 827   case GETOP: Result = "!getop"; break;
 828   }
 829   return Result + "(" + LHS->getAsString() + ")";
 830 }
 831
 832 static void
 833 ProfileBinOpInit(FoldingSetNodeID &ID, unsigned Opcode, Init *LHS, Init *RHS,
 834                  RecTy *Type) {
 835   ID.AddInteger(Opcode);
 836   ID.AddPointer(LHS);
 837   ID.AddPointer(RHS);
 838   ID.AddPointer(Type);
 839 }
 840
 841 BinOpInit *BinOpInit::get(BinaryOp Opc, Init *LHS,
 842                           Init *RHS, RecTy *Type) {
 843   static FoldingSet<BinOpInit> ThePool;
 844
 845   FoldingSetNodeID ID;
 846   ProfileBinOpInit(ID, Opc, LHS, RHS, Type);
 847
 848   void *IP = nullptr;
 849   if (BinOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
 850     return I;
 851
 852   BinOpInit *I = new(Allocator) BinOpInit(Opc, LHS, RHS, Type);
 853   ThePool.InsertNode(I, IP);
 854   return I;
 855 }
 856
 857 void BinOpInit::Profile(FoldingSetNodeID &ID) const {
 858   ProfileBinOpInit(ID, getOpcode(), getLHS(), getRHS(), getType());
 859 }
 860
 861 static StringInit *ConcatStringInits(const StringInit *I0,
 862                                      const StringInit *I1) {
 863   SmallString<80> Concat(I0->getValue());
 864   Concat.append(I1->getValue());
 865   return StringInit::get(Concat);
 866 }
 867
 868 Init *BinOpInit::getStrConcat(Init *I0, Init *I1) {
 869   // Shortcut for the common case of concatenating two strings.
 870   if (const StringInit *I0s = dyn_cast<StringInit>(I0))
 871     if (const StringInit *I1s = dyn_cast<StringInit>(I1))
 872       return ConcatStringInits(I0s, I1s);
 873   return BinOpInit::get(BinOpInit::STRCONCAT, I0, I1, StringRecTy::get());
 874 }
 875
 876 static ListInit *ConcatListInits(const ListInit *LHS,
 877                                  const ListInit *RHS) {
 878   SmallVector<Init *, 8> Args;
 879   Args.insert(Args.end(), LHS->begin(), LHS->end());
 880   Args.insert(Args.end(), RHS->begin(), RHS->end());
 881   return ListInit::get(Args, LHS->getElementType());
 882 }
 883
 884 Init *BinOpInit::getListConcat(TypedInit *LHS, Init *RHS) {
 885   assert(isa<ListRecTy>(LHS->getType()) && "First arg must be a list");
 886
 887   // Shortcut for the common case of concatenating two lists.
 888    if (const ListInit *LHSList = dyn_cast<ListInit>(LHS))
 889      if (const ListInit *RHSList = dyn_cast<ListInit>(RHS))
 890        return ConcatListInits(LHSList, RHSList);
 891    return BinOpInit::get(BinOpInit::LISTCONCAT, LHS, RHS, LHS->getType());
 892 }
 893
 894 Init *BinOpInit::getListSplat(TypedInit *LHS, Init *RHS) {
 895   return BinOpInit::get(BinOpInit::LISTSPLAT, LHS, RHS, LHS->getType());
 896 }
 897
 898 Init *BinOpInit::Fold(Record *CurRec) const {
 899   switch (getOpcode()) {
 900   case CONCAT: {
 901     DagInit *LHSs = dyn_cast<DagInit>(LHS);
 902     DagInit *RHSs = dyn_cast<DagInit>(RHS);
 903     if (LHSs && RHSs) {
 904       DefInit *LOp = dyn_cast<DefInit>(LHSs->getOperator());
 905       DefInit *ROp = dyn_cast<DefInit>(RHSs->getOperator());
 906       if ((!LOp && !isa<UnsetInit>(LHSs->getOperator())) ||
 907           (!ROp && !isa<UnsetInit>(RHSs->getOperator())))
 908         break;
 909       if (LOp && ROp && LOp->getDef() != ROp->getDef()) {
 910         PrintFatalError(Twine("Concatenated Dag operators do not match: '") +
 911                         LHSs->getAsString() + "' vs. '" + RHSs->getAsString() +
 912                         "'");
 913       }
 914       Init *Op = LOp ? LOp : ROp;
 915       if (!Op)
 916         Op = UnsetInit::get();
 917
 918       SmallVector<Init*, 8> Args;
 919       SmallVector<StringInit*, 8> ArgNames;
 920       for (unsigned i = 0, e = LHSs->getNumArgs(); i != e; ++i) {
 921         Args.push_back(LHSs->getArg(i));
 922         ArgNames.push_back(LHSs->getArgName(i));
 923       }
 924       for (unsigned i = 0, e = RHSs->getNumArgs(); i != e; ++i) {
 925         Args.push_back(RHSs->getArg(i));
 926         ArgNames.push_back(RHSs->getArgName(i));
 927       }
 928       return DagInit::get(Op, nullptr, Args, ArgNames);
 929     }
 930     break;
 931   }
 932   case LISTCONCAT: {
 933     ListInit *LHSs = dyn_cast<ListInit>(LHS);
 934     ListInit *RHSs = dyn_cast<ListInit>(RHS);
 935     if (LHSs && RHSs) {
 936       SmallVector<Init *, 8> Args;
 937       Args.insert(Args.end(), LHSs->begin(), LHSs->end());
 938       Args.insert(Args.end(), RHSs->begin(), RHSs->end());
 939       return ListInit::get(Args, LHSs->getElementType());
 940     }
 941     break;
 942   }
 943   case LISTSPLAT: {
 944     TypedInit *Value = dyn_cast<TypedInit>(LHS);
 945     IntInit *Size = dyn_cast<IntInit>(RHS);
 946     if (Value && Size) {
 947       SmallVector<Init *, 8> Args(Size->getValue(), Value);
 948       return ListInit::get(Args, Value->getType());
 949     }
 950     break;
 951   }
 952   case STRCONCAT: {
 953     StringInit *LHSs = dyn_cast<StringInit>(LHS);
 954     StringInit *RHSs = dyn_cast<StringInit>(RHS);
 955     if (LHSs && RHSs)
 956       return ConcatStringInits(LHSs, RHSs);
 957     break;
 958   }
 959   case EQ:
 960   case NE:
 961   case LE:
 962   case LT:
 963   case GE:
 964   case GT: {
 965     // try to fold eq comparison for 'bit' and 'int', otherwise fallback
 966     // to string objects.
 967     IntInit *L =
 968         dyn_cast_or_null<IntInit>(LHS->convertInitializerTo(IntRecTy::get()));
 969     IntInit *R =
 970         dyn_cast_or_null<IntInit>(RHS->convertInitializerTo(IntRecTy::get()));
 971
 972     if (L && R) {
 973       bool Result;
 974       switch (getOpcode()) {
 975       case EQ: Result = L->getValue() == R->getValue(); break;
 976       case NE: Result = L->getValue() != R->getValue(); break;
 977       case LE: Result = L->getValue() <= R->getValue(); break;
 978       case LT: Result = L->getValue() < R->getValue(); break;
 979       case GE: Result = L->getValue() >= R->getValue(); break;
 980       case GT: Result = L->getValue() > R->getValue(); break;
 981       default: llvm_unreachable("unhandled comparison");
 982       }
 983       return BitInit::get(Result);
 984     }
 985
 986     if (getOpcode() == EQ || getOpcode() == NE) {
 987       StringInit *LHSs = dyn_cast<StringInit>(LHS);
 988       StringInit *RHSs = dyn_cast<StringInit>(RHS);
 989
 990       // Make sure we've resolved
 991       if (LHSs && RHSs) {
 992         bool Equal = LHSs->getValue() == RHSs->getValue();
 993         return BitInit::get(getOpcode() == EQ ? Equal : !Equal);
 994       }
 995     }
 996
 997     break;
 998   }
 999   case SETOP: {
1000     DagInit *Dag = dyn_cast<DagInit>(LHS);
1001     DefInit *Op = dyn_cast<DefInit>(RHS);
1002     if (Dag && Op) {
1003       SmallVector<Init*, 8> Args;
1004       SmallVector<StringInit*, 8> ArgNames;
1005       for (unsigned i = 0, e = Dag->getNumArgs(); i != e; ++i) {
1006         Args.push_back(Dag->getArg(i));
1007         ArgNames.push_back(Dag->getArgName(i));
1008       }
1009       return DagInit::get(Op, nullptr, Args, ArgNames);
1010     }
1011     break;
1012   }
1013   case ADD:
1014   case MUL:
1015   case AND:
1016   case OR:
1017   case SHL:
1018   case SRA:
1019   case SRL: {
1020     IntInit *LHSi =
1021       dyn_cast_or_null<IntInit>(LHS->convertInitializerTo(IntRecTy::get()));
1022     IntInit *RHSi =
1023       dyn_cast_or_null<IntInit>(RHS->convertInitializerTo(IntRecTy::get()));
1024     if (LHSi && RHSi) {
1025       int64_t LHSv = LHSi->getValue(), RHSv = RHSi->getValue();
1026       int64_t Result;
1027       switch (getOpcode()) {
1028       default: llvm_unreachable("Bad opcode!");
1029       case ADD: Result = LHSv +  RHSv; break;
1030       case MUL: Result = LHSv *  RHSv; break;
1031       case AND: Result = LHSv &  RHSv; break;
1032       case OR: Result = LHSv | RHSv; break;
1033       case SHL: Result = LHSv << RHSv; break;
1034       case SRA: Result = LHSv >> RHSv; break;
1035       case SRL: Result = (uint64_t)LHSv >> (uint64_t)RHSv; break;
1036       }
1037       return IntInit::get(Result);
1038     }
1039     break;
1040   }
1041   }
1042   return const_cast<BinOpInit *>(this);
1043 }
1044
1045 Init *BinOpInit::resolveReferences(Resolver &R) const {
1046   Init *lhs = LHS->resolveReferences(R);
1047   Init *rhs = RHS->resolveReferences(R);
1048
1049   if (LHS != lhs || RHS != rhs)
1050     return (BinOpInit::get(getOpcode(), lhs, rhs, getType()))
1051         ->Fold(R.getCurrentRecord());
1052   return const_cast<BinOpInit *>(this);
1053 }
1054
1055 std::string BinOpInit::getAsString() const {
1056   std::string Result;
1057   switch (getOpcode()) {
1058   case CONCAT: Result = "!con"; break;
1059   case ADD: Result = "!add"; break;
1060   case MUL: Result = "!mul"; break;
1061   case AND: Result = "!and"; break;
1062   case OR: Result = "!or"; break;
1063   case SHL: Result = "!shl"; break;
1064   case SRA: Result = "!sra"; break;
1065   case SRL: Result = "!srl"; break;
1066   case EQ: Result = "!eq"; break;
1067   case NE: Result = "!ne"; break;
1068   case LE: Result = "!le"; break;
1069   case LT: Result = "!lt"; break;
1070   case GE: Result = "!ge"; break;
1071   case GT: Result = "!gt"; break;
1072   case LISTCONCAT: Result = "!listconcat"; break;
1073   case LISTSPLAT: Result = "!listsplat"; break;
1074   case STRCONCAT: Result = "!strconcat"; break;
1075   case SETOP: Result = "!setop"; break;
1076   }
1077   return Result + "(" + LHS->getAsString() + ", " + RHS->getAsString() + ")";
1078 }
1079
1080 static void
1081 ProfileTernOpInit(FoldingSetNodeID &ID, unsigned Opcode, Init *LHS, Init *MHS,
1082                   Init *RHS, RecTy *Type) {
1083   ID.AddInteger(Opcode);
1084   ID.AddPointer(LHS);
1085   ID.AddPointer(MHS);
1086   ID.AddPointer(RHS);
1087   ID.AddPointer(Type);
1088 }
1089
1090 TernOpInit *TernOpInit::get(TernaryOp Opc, Init *LHS, Init *MHS, Init *RHS,
1091                             RecTy *Type) {
1092   static FoldingSet<TernOpInit> ThePool;
1093
1094   FoldingSetNodeID ID;
1095   ProfileTernOpInit(ID, Opc, LHS, MHS, RHS, Type);
1096
1097   void *IP = nullptr;
1098   if (TernOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1099     return I;
1100
1101   TernOpInit *I = new(Allocator) TernOpInit(Opc, LHS, MHS, RHS, Type);
1102   ThePool.InsertNode(I, IP);
1103   return I;
1104 }
1105
1106 void TernOpInit::Profile(FoldingSetNodeID &ID) const {
1107   ProfileTernOpInit(ID, getOpcode(), getLHS(), getMHS(), getRHS(), getType());
1108 }
1109
1110 static Init *ForeachApply(Init *LHS, Init *MHSe, Init *RHS, Record *CurRec) {
1111   MapResolver R(CurRec);
1112   R.set(LHS, MHSe);
1113   return RHS->resolveReferences(R);
1114 }
1115
1116 static Init *ForeachDagApply(Init *LHS, DagInit *MHSd, Init *RHS,
1117                              Record *CurRec) {
1118   bool Change = false;
1119   Init *Val = ForeachApply(LHS, MHSd->getOperator(), RHS, CurRec);
1120   if (Val != MHSd->getOperator())
1121     Change = true;
1122
1123   SmallVector<std::pair<Init *, StringInit *>, 8> NewArgs;
1124   for (unsigned int i = 0; i < MHSd->getNumArgs(); ++i) {
1125     Init *Arg = MHSd->getArg(i);
1126     Init *NewArg;
1127     StringInit *ArgName = MHSd->getArgName(i);
1128
1129     if (DagInit *Argd = dyn_cast<DagInit>(Arg))
1130       NewArg = ForeachDagApply(LHS, Argd, RHS, CurRec);
1131     else
1132       NewArg = ForeachApply(LHS, Arg, RHS, CurRec);
1133
1134     NewArgs.push_back(std::make_pair(NewArg, ArgName));
1135     if (Arg != NewArg)
1136       Change = true;
1137   }
1138
1139   if (Change)
1140     return DagInit::get(Val, nullptr, NewArgs);
1141   return MHSd;
1142 }
1143
1144 // Applies RHS to all elements of MHS, using LHS as a temp variable.
1145 static Init *ForeachHelper(Init *LHS, Init *MHS, Init *RHS, RecTy *Type,
1146                            Record *CurRec) {
1147   if (DagInit *MHSd = dyn_cast<DagInit>(MHS))
1148     return ForeachDagApply(LHS, MHSd, RHS, CurRec);
1149
1150   if (ListInit *MHSl = dyn_cast<ListInit>(MHS)) {
1151     SmallVector<Init *, 8> NewList(MHSl->begin(), MHSl->end());
1152
1153     for (Init *&Item : NewList) {
1154       Init *NewItem = ForeachApply(LHS, Item, RHS, CurRec);
1155       if (NewItem != Item)
1156         Item = NewItem;
1157     }
1158     return ListInit::get(NewList, cast<ListRecTy>(Type)->getElementType());
1159   }
1160
1161   return nullptr;
1162 }
1163
1164 Init *TernOpInit::Fold(Record *CurRec) const {
1165   switch (getOpcode()) {
1166   case SUBST: {
1167     DefInit *LHSd = dyn_cast<DefInit>(LHS);
1168     VarInit *LHSv = dyn_cast<VarInit>(LHS);
1169     StringInit *LHSs = dyn_cast<StringInit>(LHS);
1170
1171     DefInit *MHSd = dyn_cast<DefInit>(MHS);
1172     VarInit *MHSv = dyn_cast<VarInit>(MHS);
1173     StringInit *MHSs = dyn_cast<StringInit>(MHS);
1174
1175     DefInit *RHSd = dyn_cast<DefInit>(RHS);
1176     VarInit *RHSv = dyn_cast<VarInit>(RHS);
1177     StringInit *RHSs = dyn_cast<StringInit>(RHS);
1178
1179     if (LHSd && MHSd && RHSd) {
1180       Record *Val = RHSd->getDef();
1181       if (LHSd->getAsString() == RHSd->getAsString())
1182         Val = MHSd->getDef();
1183       return DefInit::get(Val);
1184     }
1185     if (LHSv && MHSv && RHSv) {
1186       std::string Val = RHSv->getName();
1187       if (LHSv->getAsString() == RHSv->getAsString())
1188         Val = MHSv->getName();
1189       return VarInit::get(Val, getType());
1190     }
1191     if (LHSs && MHSs && RHSs) {
1192       std::string Val = RHSs->getValue();
1193
1194       std::string::size_type found;
1195       std::string::size_type idx = 0;
1196       while (true) {
1197         found = Val.find(LHSs->getValue(), idx);
1198         if (found == std::string::npos)
1199           break;
1200         Val.replace(found, LHSs->getValue().size(), MHSs->getValue());
1201         idx = found + MHSs->getValue().size();
1202       }
1203
1204       return StringInit::get(Val);
1205     }
1206     break;
1207   }
1208
1209   case FOREACH: {
1210     if (Init *Result = ForeachHelper(LHS, MHS, RHS, getType(), CurRec))
1211       return Result;
1212     break;
1213   }
1214
1215   case IF: {
1216     if (IntInit *LHSi = dyn_cast_or_null<IntInit>(
1217                             LHS->convertInitializerTo(IntRecTy::get()))) {
1218       if (LHSi->getValue())
1219         return MHS;
1220       return RHS;
1221     }
1222     break;
1223   }
1224
1225   case DAG: {
1226     ListInit *MHSl = dyn_cast<ListInit>(MHS);
1227     ListInit *RHSl = dyn_cast<ListInit>(RHS);
1228     bool MHSok = MHSl || isa<UnsetInit>(MHS);
1229     bool RHSok = RHSl || isa<UnsetInit>(RHS);
1230
1231     if (isa<UnsetInit>(MHS) && isa<UnsetInit>(RHS))
1232       break; // Typically prevented by the parser, but might happen with template args
1233
1234     if (MHSok && RHSok && (!MHSl || !RHSl || MHSl->size() == RHSl->size())) {
1235       SmallVector<std::pair<Init *, StringInit *>, 8> Children;
1236       unsigned Size = MHSl ? MHSl->size() : RHSl->size();
1237       for (unsigned i = 0; i != Size; ++i) {
1238         Init *Node = MHSl ? MHSl->getElement(i) : UnsetInit::get();
1239         Init *Name = RHSl ? RHSl->getElement(i) : UnsetInit::get();
1240         if (!isa<StringInit>(Name) && !isa<UnsetInit>(Name))
1241           return const_cast<TernOpInit *>(this);
1242         Children.emplace_back(Node, dyn_cast<StringInit>(Name));
1243       }
1244       return DagInit::get(LHS, nullptr, Children);
1245     }
1246     break;
1247   }
1248   }
1249
1250   return const_cast<TernOpInit *>(this);
1251 }
1252
1253 Init *TernOpInit::resolveReferences(Resolver &R) const {
1254   Init *lhs = LHS->resolveReferences(R);
1255
1256   if (getOpcode() == IF && lhs != LHS) {
1257     if (IntInit *Value = dyn_cast_or_null<IntInit>(
1258                              lhs->convertInitializerTo(IntRecTy::get()))) {
1259       // Short-circuit
1260       if (Value->getValue())
1261         return MHS->resolveReferences(R);
1262       return RHS->resolveReferences(R);
1263     }
1264   }
1265
1266   Init *mhs = MHS->resolveReferences(R);
1267   Init *rhs;
1268
1269   if (getOpcode() == FOREACH) {
1270     ShadowResolver SR(R);
1271     SR.addShadow(lhs);
1272     rhs = RHS->resolveReferences(SR);
1273   } else {
1274     rhs = RHS->resolveReferences(R);
1275   }
1276
1277   if (LHS != lhs || MHS != mhs || RHS != rhs)
1278     return (TernOpInit::get(getOpcode(), lhs, mhs, rhs, getType()))
1279         ->Fold(R.getCurrentRecord());
1280   return const_cast<TernOpInit *>(this);
1281 }
1282
1283 std::string TernOpInit::getAsString() const {
1284   std::string Result;
1285   bool UnquotedLHS = false;
1286   switch (getOpcode()) {
1287   case SUBST: Result = "!subst"; break;
1288   case FOREACH: Result = "!foreach"; UnquotedLHS = true; break;
1289   case IF: Result = "!if"; break;
1290   case DAG: Result = "!dag"; break;
1291   }
1292   return (Result + "(" +
1293           (UnquotedLHS ? LHS->getAsUnquotedString() : LHS->getAsString()) +
1294           ", " + MHS->getAsString() + ", " + RHS->getAsString() + ")");
1295 }
1296
1297 static void ProfileFoldOpInit(FoldingSetNodeID &ID, Init *A, Init *B,
1298                               Init *Start, Init *List, Init *Expr,
1299                               RecTy *Type) {
1300   ID.AddPointer(Start);
1301   ID.AddPointer(List);
1302   ID.AddPointer(A);
1303   ID.AddPointer(B);
1304   ID.AddPointer(Expr);
1305   ID.AddPointer(Type);
1306 }
1307
1308 FoldOpInit *FoldOpInit::get(Init *Start, Init *List, Init *A, Init *B,
1309                             Init *Expr, RecTy *Type) {
1310   static FoldingSet<FoldOpInit> ThePool;
1311
1312   FoldingSetNodeID ID;
1313   ProfileFoldOpInit(ID, Start, List, A, B, Expr, Type);
1314
1315   void *IP = nullptr;
1316   if (FoldOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1317     return I;
1318
1319   FoldOpInit *I = new (Allocator) FoldOpInit(Start, List, A, B, Expr, Type);
1320   ThePool.InsertNode(I, IP);
1321   return I;
1322 }
1323
1324 void FoldOpInit::Profile(FoldingSetNodeID &ID) const {
1325   ProfileFoldOpInit(ID, Start, List, A, B, Expr, getType());
1326 }
1327
1328 Init *FoldOpInit::Fold(Record *CurRec) const {
1329   if (ListInit *LI = dyn_cast<ListInit>(List)) {
1330     Init *Accum = Start;
1331     for (Init *Elt : *LI) {
1332       MapResolver R(CurRec);
1333       R.set(A, Accum);
1334       R.set(B, Elt);
1335       Accum = Expr->resolveReferences(R);
1336     }
1337     return Accum;
1338   }
1339   return const_cast<FoldOpInit *>(this);
1340 }
1341
1342 Init *FoldOpInit::resolveReferences(Resolver &R) const {
1343   Init *NewStart = Start->resolveReferences(R);
1344   Init *NewList = List->resolveReferences(R);
1345   ShadowResolver SR(R);
1346   SR.addShadow(A);
1347   SR.addShadow(B);
1348   Init *NewExpr = Expr->resolveReferences(SR);
1349
1350   if (Start == NewStart && List == NewList && Expr == NewExpr)
1351     return const_cast<FoldOpInit *>(this);
1352
1353   return get(NewStart, NewList, A, B, NewExpr, getType())
1354       ->Fold(R.getCurrentRecord());
1355 }
1356
1357 Init *FoldOpInit::getBit(unsigned Bit) const {
1358   return VarBitInit::get(const_cast<FoldOpInit *>(this), Bit);
1359 }
1360
1361 std::string FoldOpInit::getAsString() const {
1362   return (Twine("!foldl(") + Start->getAsString() + ", " + List->getAsString() +
1363           ", " + A->getAsUnquotedString() + ", " + B->getAsUnquotedString() +
1364           ", " + Expr->getAsString() + ")")
1365       .str();
1366 }
1367
1368 static void ProfileIsAOpInit(FoldingSetNodeID &ID, RecTy *CheckType,
1369                              Init *Expr) {
1370   ID.AddPointer(CheckType);
1371   ID.AddPointer(Expr);
1372 }
1373
1374 IsAOpInit *IsAOpInit::get(RecTy *CheckType, Init *Expr) {
1375   static FoldingSet<IsAOpInit> ThePool;
1376
1377   FoldingSetNodeID ID;
1378   ProfileIsAOpInit(ID, CheckType, Expr);
1379
1380   void *IP = nullptr;
1381   if (IsAOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1382     return I;
1383
1384   IsAOpInit *I = new (Allocator) IsAOpInit(CheckType, Expr);
1385   ThePool.InsertNode(I, IP);
1386   return I;
1387 }
1388
1389 void IsAOpInit::Profile(FoldingSetNodeID &ID) const {
1390   ProfileIsAOpInit(ID, CheckType, Expr);
1391 }
1392
1393 Init *IsAOpInit::Fold() const {
1394   if (TypedInit *TI = dyn_cast<TypedInit>(Expr)) {
1395     // Is the expression type known to be (a subclass of) the desired type?
1396     if (TI->getType()->typeIsConvertibleTo(CheckType))
1397       return IntInit::get(1);
1398
1399     if (isa<RecordRecTy>(CheckType)) {
1400       // If the target type is not a subclass of the expression type, or if
1401       // the expression has fully resolved to a record, we know that it can't
1402       // be of the required type.
1403       if (!CheckType->typeIsConvertibleTo(TI->getType()) || isa<DefInit>(Expr))
1404         return IntInit::get(0);
1405     } else {
1406       // We treat non-record types as not castable.
1407       return IntInit::get(0);
1408     }
1409   }
1410   return const_cast<IsAOpInit *>(this);
1411 }
1412
1413 Init *IsAOpInit::resolveReferences(Resolver &R) const {
1414   Init *NewExpr = Expr->resolveReferences(R);
1415   if (Expr != NewExpr)
1416     return get(CheckType, NewExpr)->Fold();
1417   return const_cast<IsAOpInit *>(this);
1418 }
1419
1420 Init *IsAOpInit::getBit(unsigned Bit) const {
1421   return VarBitInit::get(const_cast<IsAOpInit *>(this), Bit);
1422 }
1423
1424 std::string IsAOpInit::getAsString() const {
1425   return (Twine("!isa<") + CheckType->getAsString() + ">(" +
1426           Expr->getAsString() + ")")
1427       .str();
1428 }
1429
1430 RecTy *TypedInit::getFieldType(StringInit *FieldName) const {
1431   if (RecordRecTy *RecordType = dyn_cast<RecordRecTy>(getType())) {
1432     for (Record *Rec : RecordType->getClasses()) {
1433       if (RecordVal *Field = Rec->getValue(FieldName))
1434         return Field->getType();
1435     }
1436   }
1437   return nullptr;
1438 }
1439
1440 Init *
1441 TypedInit::convertInitializerTo(RecTy *Ty) const {
1442   if (getType() == Ty || getType()->typeIsA(Ty))
1443     return const_cast<TypedInit *>(this);
1444
1445   if (isa<BitRecTy>(getType()) && isa<BitsRecTy>(Ty) &&
1446       cast<BitsRecTy>(Ty)->getNumBits() == 1)
1447     return BitsInit::get({const_cast<TypedInit *>(this)});
1448
1449   return nullptr;
1450 }
1451
1452 Init *TypedInit::convertInitializerBitRange(ArrayRef<unsigned> Bits) const {
1453   BitsRecTy *T = dyn_cast<BitsRecTy>(getType());
1454   if (!T) return nullptr;  // Cannot subscript a non-bits variable.
1455   unsigned NumBits = T->getNumBits();
1456
1457   SmallVector<Init *, 16> NewBits;
1458   NewBits.reserve(Bits.size());
1459   for (unsigned Bit : Bits) {
1460     if (Bit >= NumBits)
1461       return nullptr;
1462
1463     NewBits.push_back(VarBitInit::get(const_cast<TypedInit *>(this), Bit));
1464   }
1465   return BitsInit::get(NewBits);
1466 }
1467
1468 Init *TypedInit::getCastTo(RecTy *Ty) const {
1469   // Handle the common case quickly
1470   if (getType() == Ty || getType()->typeIsA(Ty))
1471     return const_cast<TypedInit *>(this);
1472
1473   if (Init *Converted = convertInitializerTo(Ty)) {
1474     assert(!isa<TypedInit>(Converted) ||
1475            cast<TypedInit>(Converted)->getType()->typeIsA(Ty));
1476     return Converted;
1477   }
1478
1479   if (!getType()->typeIsConvertibleTo(Ty))
1480     return nullptr;
1481
1482   return UnOpInit::get(UnOpInit::CAST, const_cast<TypedInit *>(this), Ty)
1483       ->Fold(nullptr);
1484 }
1485
1486 Init *TypedInit::convertInitListSlice(ArrayRef<unsigned> Elements) const {
1487   ListRecTy *T = dyn_cast<ListRecTy>(getType());
1488   if (!T) return nullptr;  // Cannot subscript a non-list variable.
1489
1490   if (Elements.size() == 1)
1491     return VarListElementInit::get(const_cast<TypedInit *>(this), Elements[0]);
1492
1493   SmallVector<Init*, 8> ListInits;
1494   ListInits.reserve(Elements.size());
1495   for (unsigned Element : Elements)
1496     ListInits.push_back(VarListElementInit::get(const_cast<TypedInit *>(this),
1497                                                 Element));
1498   return ListInit::get(ListInits, T->getElementType());
1499 }
1500
1501
1502 VarInit *VarInit::get(StringRef VN, RecTy *T) {
1503   Init *Value = StringInit::get(VN);
1504   return VarInit::get(Value, T);
1505 }
1506
1507 VarInit *VarInit::get(Init *VN, RecTy *T) {
1508   using Key = std::pair<RecTy *, Init *>;
1509   static DenseMap<Key, VarInit*> ThePool;
1510
1511   Key TheKey(std::make_pair(T, VN));
1512
1513   VarInit *&I = ThePool[TheKey];
1514   if (!I)
1515     I = new(Allocator) VarInit(VN, T);
1516   return I;
1517 }
1518
1519 StringRef VarInit::getName() const {
1520   StringInit *NameString = cast<StringInit>(getNameInit());
1521   return NameString->getValue();
1522 }
1523
1524 Init *VarInit::getBit(unsigned Bit) const {
1525   if (getType() == BitRecTy::get())
1526     return const_cast<VarInit*>(this);
1527   return VarBitInit::get(const_cast<VarInit*>(this), Bit);
1528 }
1529
1530 Init *VarInit::resolveReferences(Resolver &R) const {
1531   if (Init *Val = R.resolve(VarName))
1532     return Val;
1533   return const_cast<VarInit *>(this);
1534 }
1535
1536 VarBitInit *VarBitInit::get(TypedInit *T, unsigned B) {
1537   using Key = std::pair<TypedInit *, unsigned>;
1538   static DenseMap<Key, VarBitInit*> ThePool;
1539
1540   Key TheKey(std::make_pair(T, B));
1541
1542   VarBitInit *&I = ThePool[TheKey];
1543   if (!I)
1544     I = new(Allocator) VarBitInit(T, B);
1545   return I;
1546 }
1547
1548 std::string VarBitInit::getAsString() const {
1549   return TI->getAsString() + "{" + utostr(Bit) + "}";
1550 }
1551
1552 Init *VarBitInit::resolveReferences(Resolver &R) const {
1553   Init *I = TI->resolveReferences(R);
1554   if (TI != I)
1555     return I->getBit(getBitNum());
1556
1557   return const_cast<VarBitInit*>(this);
1558 }
1559
1560 VarListElementInit *VarListElementInit::get(TypedInit *T,
1561                                             unsigned E) {
1562   using Key = std::pair<TypedInit *, unsigned>;
1563   static DenseMap<Key, VarListElementInit*> ThePool;
1564
1565   Key TheKey(std::make_pair(T, E));
1566
1567   VarListElementInit *&I = ThePool[TheKey];
1568   if (!I) I = new(Allocator) VarListElementInit(T, E);
1569   return I;
1570 }
1571
1572 std::string VarListElementInit::getAsString() const {
1573   return TI->getAsString() + "[" + utostr(Element) + "]";
1574 }
1575
1576 Init *VarListElementInit::resolveReferences(Resolver &R) const {
1577   Init *NewTI = TI->resolveReferences(R);
1578   if (ListInit *List = dyn_cast<ListInit>(NewTI)) {
1579     // Leave out-of-bounds array references as-is. This can happen without
1580     // being an error, e.g. in the untaken "branch" of an !if expression.
1581     if (getElementNum() < List->size())
1582       return List->getElement(getElementNum());
1583   }
1584   if (NewTI != TI && isa<TypedInit>(NewTI))
1585     return VarListElementInit::get(cast<TypedInit>(NewTI), getElementNum());
1586   return const_cast<VarListElementInit *>(this);
1587 }
1588
1589 Init *VarListElementInit::getBit(unsigned Bit) const {
1590   if (getType() == BitRecTy::get())
1591     return const_cast<VarListElementInit*>(this);
1592   return VarBitInit::get(const_cast<VarListElementInit*>(this), Bit);
1593 }
1594
1595 DefInit::DefInit(Record *D)
1596     : TypedInit(IK_DefInit, D->getType()), Def(D) {}
1597
1598 DefInit *DefInit::get(Record *R) {
1599   return R->getDefInit();
1600 }
1601
1602 Init *DefInit::convertInitializerTo(RecTy *Ty) const {
1603   if (auto *RRT = dyn_cast<RecordRecTy>(Ty))
1604     if (getType()->typeIsConvertibleTo(RRT))
1605       return const_cast<DefInit *>(this);
1606   return nullptr;
1607 }
1608
1609 RecTy *DefInit::getFieldType(StringInit *FieldName) const {
1610   if (const RecordVal *RV = Def->getValue(FieldName))
1611     return RV->getType();
1612   return nullptr;
1613 }
1614
1615 std::string DefInit::getAsString() const {
1616   return Def->getName();
1617 }
1618
1619 static void ProfileVarDefInit(FoldingSetNodeID &ID,
1620                               Record *Class,
1621                               ArrayRef<Init *> Args) {
1622   ID.AddInteger(Args.size());
1623   ID.AddPointer(Class);
1624
1625   for (Init *I : Args)
1626     ID.AddPointer(I);
1627 }
1628
1629 VarDefInit *VarDefInit::get(Record *Class, ArrayRef<Init *> Args) {
1630   static FoldingSet<VarDefInit> ThePool;
1631
1632   FoldingSetNodeID ID;
1633   ProfileVarDefInit(ID, Class, Args);
1634
1635   void *IP = nullptr;
1636   if (VarDefInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1637     return I;
1638
1639   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(Args.size()),
1640                                  alignof(VarDefInit));
1641   VarDefInit *I = new(Mem) VarDefInit(Class, Args.size());
1642   std::uninitialized_copy(Args.begin(), Args.end(),
1643                           I->getTrailingObjects<Init *>());
1644   ThePool.InsertNode(I, IP);
1645   return I;
1646 }
1647
1648 void VarDefInit::Profile(FoldingSetNodeID &ID) const {
1649   ProfileVarDefInit(ID, Class, args());
1650 }
1651
1652 DefInit *VarDefInit::instantiate() {
1653   if (!Def) {
1654     RecordKeeper &Records = Class->getRecords();
1655     auto NewRecOwner = std::make_unique<Record>(Records.getNewAnonymousName(),
1656                                            Class->getLoc(), Records,
1657                                            /*IsAnonymous=*/true);
1658     Record *NewRec = NewRecOwner.get();
1659
1660     // Copy values from class to instance
1661     for (const RecordVal &Val : Class->getValues())
1662       NewRec->addValue(Val);
1663
1664     // Substitute and resolve template arguments
1665     ArrayRef<Init *> TArgs = Class->getTemplateArgs();
1666     MapResolver R(NewRec);
1667
1668     for (unsigned i = 0, e = TArgs.size(); i != e; ++i) {
1669       if (i < args_size())
1670         R.set(TArgs[i], getArg(i));
1671       else
1672         R.set(TArgs[i], NewRec->getValue(TArgs[i])->getValue());
1673
1674       NewRec->removeValue(TArgs[i]);
1675     }
1676
1677     NewRec->resolveReferences(R);
1678
1679     // Add superclasses.
1680     ArrayRef<std::pair<Record *, SMRange>> SCs = Class->getSuperClasses();
1681     for (const auto &SCPair : SCs)
1682       NewRec->addSuperClass(SCPair.first, SCPair.second);
1683
1684     NewRec->addSuperClass(Class,
1685                           SMRange(Class->getLoc().back(),
1686                                   Class->getLoc().back()));
1687
1688     // Resolve internal references and store in record keeper
1689     NewRec->resolveReferences();
1690     Records.addDef(std::move(NewRecOwner));
1691
1692     Def = DefInit::get(NewRec);
1693   }
1694
1695   return Def;
1696 }
1697
1698 Init *VarDefInit::resolveReferences(Resolver &R) const {
1699   TrackUnresolvedResolver UR(&R);
1700   bool Changed = false;
1701   SmallVector<Init *, 8> NewArgs;
1702   NewArgs.reserve(args_size());
1703
1704   for (Init *Arg : args()) {
1705     Init *NewArg = Arg->resolveReferences(UR);
1706     NewArgs.push_back(NewArg);
1707     Changed |= NewArg != Arg;
1708   }
1709
1710   if (Changed) {
1711     auto New = VarDefInit::get(Class, NewArgs);
1712     if (!UR.foundUnresolved())
1713       return New->instantiate();
1714     return New;
1715   }
1716   return const_cast<VarDefInit *>(this);
1717 }
1718
1719 Init *VarDefInit::Fold() const {
1720   if (Def)
1721     return Def;
1722
1723   TrackUnresolvedResolver R;
1724   for (Init *Arg : args())
1725     Arg->resolveReferences(R);
1726
1727   if (!R.foundUnresolved())
1728     return const_cast<VarDefInit *>(this)->instantiate();
1729   return const_cast<VarDefInit *>(this);
1730 }
1731
1732 std::string VarDefInit::getAsString() const {
1733   std::string Result = Class->getNameInitAsString() + "<";
1734   const char *sep = "";
1735   for (Init *Arg : args()) {
1736     Result += sep;
1737     sep = ", ";
1738     Result += Arg->getAsString();
1739   }
1740   return Result + ">";
1741 }
1742
1743 FieldInit *FieldInit::get(Init *R, StringInit *FN) {
1744   using Key = std::pair<Init *, StringInit *>;
1745   static DenseMap<Key, FieldInit*> ThePool;
1746
1747   Key TheKey(std::make_pair(R, FN));
1748
1749   FieldInit *&I = ThePool[TheKey];
1750   if (!I) I = new(Allocator) FieldInit(R, FN);
1751   return I;
1752 }
1753
1754 Init *FieldInit::getBit(unsigned Bit) const {
1755   if (getType() == BitRecTy::get())
1756     return const_cast<FieldInit*>(this);
1757   return VarBitInit::get(const_cast<FieldInit*>(this), Bit);
1758 }
1759
1760 Init *FieldInit::resolveReferences(Resolver &R) const {
1761   Init *NewRec = Rec->resolveReferences(R);
1762   if (NewRec != Rec)
1763     return FieldInit::get(NewRec, FieldName)->Fold(R.getCurrentRecord());
1764   return const_cast<FieldInit *>(this);
1765 }
1766
1767 Init *FieldInit::Fold(Record *CurRec) const {
1768   if (DefInit *DI = dyn_cast<DefInit>(Rec)) {
1769     Record *Def = DI->getDef();
1770     if (Def == CurRec)
1771       PrintFatalError(CurRec->getLoc(),
1772                       Twine("Attempting to access field '") +
1773                       FieldName->getAsUnquotedString() + "' of '" +
1774                       Rec->getAsString() + "' is a forbidden self-reference");
1775     Init *FieldVal = Def->getValue(FieldName)->getValue();
1776     if (FieldVal->isComplete())
1777       return FieldVal;
1778   }
1779   return const_cast<FieldInit *>(this);
1780 }
1781
1782 static void ProfileCondOpInit(FoldingSetNodeID &ID,
1783                              ArrayRef<Init *> CondRange,
1784                              ArrayRef<Init *> ValRange,
1785                              const RecTy *ValType) {
1786   assert(CondRange.size() == ValRange.size() &&
1787          "Number of conditions and values must match!");
1788   ID.AddPointer(ValType);
1789   ArrayRef<Init *>::iterator Case = CondRange.begin();
1790   ArrayRef<Init *>::iterator Val = ValRange.begin();
1791
1792   while (Case != CondRange.end()) {
1793     ID.AddPointer(*Case++);
1794     ID.AddPointer(*Val++);
1795   }
1796 }
1797
1798 void CondOpInit::Profile(FoldingSetNodeID &ID) const {
1799   ProfileCondOpInit(ID,
1800       makeArrayRef(getTrailingObjects<Init *>(), NumConds),
1801       makeArrayRef(getTrailingObjects<Init *>() + NumConds, NumConds),
1802       ValType);
1803 }
1804
1805 CondOpInit *
1806 CondOpInit::get(ArrayRef<Init *> CondRange,
1807                 ArrayRef<Init *> ValRange, RecTy *Ty) {
1808   assert(CondRange.size() == ValRange.size() &&
1809          "Number of conditions and values must match!");
1810
1811   static FoldingSet<CondOpInit> ThePool;
1812   FoldingSetNodeID ID;
1813   ProfileCondOpInit(ID, CondRange, ValRange, Ty);
1814
1815   void *IP = nullptr;
1816   if (CondOpInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1817     return I;
1818
1819   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *>(2*CondRange.size()),
1820                                  alignof(BitsInit));
1821   CondOpInit *I = new(Mem) CondOpInit(CondRange.size(), Ty);
1822
1823   std::uninitialized_copy(CondRange.begin(), CondRange.end(),
1824                           I->getTrailingObjects<Init *>());
1825   std::uninitialized_copy(ValRange.begin(), ValRange.end(),
1826                           I->getTrailingObjects<Init *>()+CondRange.size());
1827   ThePool.InsertNode(I, IP);
1828   return I;
1829 }
1830
1831 Init *CondOpInit::resolveReferences(Resolver &R) const {
1832   SmallVector<Init*, 4> NewConds;
1833   bool Changed = false;
1834   for (const Init *Case : getConds()) {
1835     Init *NewCase = Case->resolveReferences(R);
1836     NewConds.push_back(NewCase);
1837     Changed |= NewCase != Case;
1838   }
1839
1840   SmallVector<Init*, 4> NewVals;
1841   for (const Init *Val : getVals()) {
1842     Init *NewVal = Val->resolveReferences(R);
1843     NewVals.push_back(NewVal);
1844     Changed |= NewVal != Val;
1845   }
1846
1847   if (Changed)
1848     return (CondOpInit::get(NewConds, NewVals,
1849             getValType()))->Fold(R.getCurrentRecord());
1850
1851   return const_cast<CondOpInit *>(this);
1852 }
1853
1854 Init *CondOpInit::Fold(Record *CurRec) const {
1855   for ( unsigned i = 0; i < NumConds; ++i) {
1856     Init *Cond = getCond(i);
1857     Init *Val = getVal(i);
1858
1859     if (IntInit *CondI = dyn_cast_or_null<IntInit>(
1860             Cond->convertInitializerTo(IntRecTy::get()))) {
1861       if (CondI->getValue())
1862         return Val->convertInitializerTo(getValType());
1863     } else
1864      return const_cast<CondOpInit *>(this);
1865   }
1866
1867   PrintFatalError(CurRec->getLoc(),
1868                   CurRec->getName() +
1869                   " does not have any true condition in:" +
1870                   this->getAsString());
1871   return nullptr;
1872 }
1873
1874 bool CondOpInit::isConcrete() const {
1875   for (const Init *Case : getConds())
1876     if (!Case->isConcrete())
1877       return false;
1878
1879   for (const Init *Val : getVals())
1880     if (!Val->isConcrete())
1881       return false;
1882
1883   return true;
1884 }
1885
1886 bool CondOpInit::isComplete() const {
1887   for (const Init *Case : getConds())
1888     if (!Case->isComplete())
1889       return false;
1890
1891   for (const Init *Val : getVals())
1892     if (!Val->isConcrete())
1893       return false;
1894
1895   return true;
1896 }
1897
1898 std::string CondOpInit::getAsString() const {
1899   std::string Result = "!cond(";
1900   for (unsigned i = 0; i < getNumConds(); i++) {
1901     Result += getCond(i)->getAsString() + ": ";
1902     Result += getVal(i)->getAsString();
1903     if (i != getNumConds()-1)
1904       Result += ", ";
1905   }
1906   return Result + ")";
1907 }
1908
1909 Init *CondOpInit::getBit(unsigned Bit) const {
1910   return VarBitInit::get(const_cast<CondOpInit *>(this), Bit);
1911 }
1912
1913 static void ProfileDagInit(FoldingSetNodeID &ID, Init *V, StringInit *VN,
1914                            ArrayRef<Init *> ArgRange,
1915                            ArrayRef<StringInit *> NameRange) {
1916   ID.AddPointer(V);
1917   ID.AddPointer(VN);
1918
1919   ArrayRef<Init *>::iterator Arg = ArgRange.begin();
1920   ArrayRef<StringInit *>::iterator Name = NameRange.begin();
1921   while (Arg != ArgRange.end()) {
1922     assert(Name != NameRange.end() && "Arg name underflow!");
1923     ID.AddPointer(*Arg++);
1924     ID.AddPointer(*Name++);
1925   }
1926   assert(Name == NameRange.end() && "Arg name overflow!");
1927 }
1928
1929 DagInit *
1930 DagInit::get(Init *V, StringInit *VN, ArrayRef<Init *> ArgRange,
1931              ArrayRef<StringInit *> NameRange) {
1932   static FoldingSet<DagInit> ThePool;
1933
1934   FoldingSetNodeID ID;
1935   ProfileDagInit(ID, V, VN, ArgRange, NameRange);
1936
1937   void *IP = nullptr;
1938   if (DagInit *I = ThePool.FindNodeOrInsertPos(ID, IP))
1939     return I;
1940
1941   void *Mem = Allocator.Allocate(totalSizeToAlloc<Init *, StringInit *>(ArgRange.size(), NameRange.size()), alignof(BitsInit));
1942   DagInit *I = new(Mem) DagInit(V, VN, ArgRange.size(), NameRange.size());
1943   std::uninitialized_copy(ArgRange.begin(), ArgRange.end(),
1944                           I->getTrailingObjects<Init *>());
1945   std::uninitialized_copy(NameRange.begin(), NameRange.end(),
1946                           I->getTrailingObjects<StringInit *>());
1947   ThePool.InsertNode(I, IP);
1948   return I;
1949 }
1950
1951 DagInit *
1952 DagInit::get(Init *V, StringInit *VN,
1953              ArrayRef<std::pair<Init*, StringInit*>> args) {
1954   SmallVector<Init *, 8> Args;
1955   SmallVector<StringInit *, 8> Names;
1956
1957   for (const auto &Arg : args) {
1958     Args.push_back(Arg.first);
1959     Names.push_back(Arg.second);
1960   }
1961
1962   return DagInit::get(V, VN, Args, Names);
1963 }
1964
1965 void DagInit::Profile(FoldingSetNodeID &ID) const {
1966   ProfileDagInit(ID, Val, ValName, makeArrayRef(getTrailingObjects<Init *>(), NumArgs), makeArrayRef(getTrailingObjects<StringInit *>(), NumArgNames));
1967 }
1968
1969 Record *DagInit::getOperatorAsDef(ArrayRef<SMLoc> Loc) const {
1970   if (DefInit *DefI = dyn_cast<DefInit>(Val))
1971     return DefI->getDef();
1972   PrintFatalError(Loc, "Expected record as operator");
1973   return nullptr;
1974 }
1975
1976 Init *DagInit::resolveReferences(Resolver &R) const {
1977   SmallVector<Init*, 8> NewArgs;
1978   NewArgs.reserve(arg_size());
1979   bool ArgsChanged = false;
1980   for (const Init *Arg : getArgs()) {
1981     Init *NewArg = Arg->resolveReferences(R);
1982     NewArgs.push_back(NewArg);
1983     ArgsChanged |= NewArg != Arg;
1984   }
1985
1986   Init *Op = Val->resolveReferences(R);
1987   if (Op != Val || ArgsChanged)
1988     return DagInit::get(Op, ValName, NewArgs, getArgNames());
1989
1990   return const_cast<DagInit *>(this);
1991 }
1992
1993 bool DagInit::isConcrete() const {
1994   if (!Val->isConcrete())
1995     return false;
1996   for (const Init *Elt : getArgs()) {
1997     if (!Elt->isConcrete())
1998       return false;
1999   }
2000   return true;
2001 }
2002
2003 std::string DagInit::getAsString() const {
2004   std::string Result = "(" + Val->getAsString();
2005   if (ValName)
2006     Result += ":" + ValName->getAsUnquotedString();
2007   if (!arg_empty()) {
2008     Result += " " + getArg(0)->getAsString();
2009     if (getArgName(0)) Result += ":$" + getArgName(0)->getAsUnquotedString();
2010     for (unsigned i = 1, e = getNumArgs(); i != e; ++i) {
2011       Result += ", " + getArg(i)->getAsString();
2012       if (getArgName(i)) Result += ":$" + getArgName(i)->getAsUnquotedString();
2013     }
2014   }
2015   return Result + ")";
2016 }
2017
2018 //===----------------------------------------------------------------------===//
2019 //    Other implementations
2020 //===----------------------------------------------------------------------===//
2021
2022 RecordVal::RecordVal(Init *N, RecTy *T, bool P)
2023   : Name(N), TyAndPrefix(T, P) {
2024   setValue(UnsetInit::get());
2025   assert(Value && "Cannot create unset value for current type!");
2026 }
2027
2028 StringRef RecordVal::getName() const {
2029   return cast<StringInit>(getNameInit())->getValue();
2030 }
2031
2032 bool RecordVal::setValue(Init *V) {
2033   if (V) {
2034     Value = V->getCastTo(getType());
2035     if (Value) {
2036       assert(!isa<TypedInit>(Value) ||
2037              cast<TypedInit>(Value)->getType()->typeIsA(getType()));
2038       if (BitsRecTy *BTy = dyn_cast<BitsRecTy>(getType())) {
2039         if (!isa<BitsInit>(Value)) {
2040           SmallVector<Init *, 64> Bits;
2041           Bits.reserve(BTy->getNumBits());
2042           for (unsigned i = 0, e = BTy->getNumBits(); i < e; ++i)
2043             Bits.push_back(Value->getBit(i));
2044           Value = BitsInit::get(Bits);
2045         }
2046       }
2047     }
2048     return Value == nullptr;
2049   }
2050   Value = nullptr;
2051   return false;
2052 }
2053
2054 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
2055 LLVM_DUMP_METHOD void RecordVal::dump() const { errs() << *this; }
2056 #endif
2057
2058 void RecordVal::print(raw_ostream &OS, bool PrintSem) const {
2059   if (getPrefix()) OS << "field ";
2060   OS << *getType() << " " << getNameInitAsString();
2061
2062   if (getValue())
2063     OS << " = " << *getValue();
2064
2065   if (PrintSem) OS << ";\n";
2066 }
2067
2068 unsigned Record::LastID = 0;
2069
2070 void Record::checkName() {
2071   // Ensure the record name has string type.
2072   const TypedInit *TypedName = cast<const TypedInit>(Name);
2073   if (!isa<StringRecTy>(TypedName->getType()))
2074     PrintFatalError(getLoc(), Twine("Record name '") + Name->getAsString() +
2075                                   "' is not a string!");
2076 }
2077
2078 RecordRecTy *Record::getType() {
2079   SmallVector<Record *, 4> DirectSCs;
2080   getDirectSuperClasses(DirectSCs);
2081   return RecordRecTy::get(DirectSCs);
2082 }
2083
2084 DefInit *Record::getDefInit() {
2085   if (!TheInit)
2086     TheInit = new(Allocator) DefInit(this);
2087   return TheInit;
2088 }
2089
2090 void Record::setName(Init *NewName) {
2091   Name = NewName;
2092   checkName();
2093   // DO NOT resolve record values to the name at this point because
2094   // there might be default values for arguments of this def.  Those
2095   // arguments might not have been resolved yet so we don't want to
2096   // prematurely assume values for those arguments were not passed to
2097   // this def.
2098   //
2099   // Nonetheless, it may be that some of this Record's values
2100   // reference the record name.  Indeed, the reason for having the
2101   // record name be an Init is to provide this flexibility.  The extra
2102   // resolve steps after completely instantiating defs takes care of
2103   // this.  See TGParser::ParseDef and TGParser::ParseDefm.
2104 }
2105
2106 void Record::getDirectSuperClasses(SmallVectorImpl<Record *> &Classes) const {
2107   ArrayRef<std::pair<Record *, SMRange>> SCs = getSuperClasses();
2108   while (!SCs.empty()) {
2109     // Superclasses are in reverse preorder, so 'back' is a direct superclass,
2110     // and its transitive superclasses are directly preceding it.
2111     Record *SC = SCs.back().first;
2112     SCs = SCs.drop_back(1 + SC->getSuperClasses().size());
2113     Classes.push_back(SC);
2114   }
2115 }
2116
2117 void Record::resolveReferences(Resolver &R, const RecordVal *SkipVal) {
2118   for (RecordVal &Value : Values) {
2119     if (SkipVal == &Value) // Skip resolve the same field as the given one
2120       continue;
2121     if (Init *V = Value.getValue()) {
2122       Init *VR = V->resolveReferences(R);
2123       if (Value.setValue(VR)) {
2124         std::string Type;
2125         if (TypedInit *VRT = dyn_cast<TypedInit>(VR))
2126           Type =
2127               (Twine("of type '") + VRT->getType()->getAsString() + "' ").str();
2128         PrintFatalError(getLoc(), Twine("Invalid value ") + Type +
2129                                       "is found when setting '" +
2130                                       Value.getNameInitAsString() +
2131                                       "' of type '" +
2132                                       Value.getType()->getAsString() +
2133                                       "' after resolving references: " +
2134                                       VR->getAsUnquotedString() + "\n");
2135       }
2136     }
2137   }
2138   Init *OldName = getNameInit();
2139   Init *NewName = Name->resolveReferences(R);
2140   if (NewName != OldName) {
2141     // Re-register with RecordKeeper.
2142     setName(NewName);
2143   }
2144 }
2145
2146 void Record::resolveReferences() {
2147   RecordResolver R(*this);
2148   R.setFinal(true);
2149   resolveReferences(R);
2150 }
2151
2152 void Record::resolveReferencesTo(const RecordVal *RV) {
2153   RecordValResolver R(*this, RV);
2154   resolveReferences(R, RV);
2155 }
2156
2157 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
2158 LLVM_DUMP_METHOD void Record::dump() const { errs() << *this; }
2159 #endif
2160
2161 raw_ostream &llvm::operator<<(raw_ostream &OS, const Record &R) {
2162   OS << R.getNameInitAsString();
2163
2164   ArrayRef<Init *> TArgs = R.getTemplateArgs();
2165   if (!TArgs.empty()) {
2166     OS << "<";
2167     bool NeedComma = false;
2168     for (const Init *TA : TArgs) {
2169       if (NeedComma) OS << ", ";
2170       NeedComma = true;
2171       const RecordVal *RV = R.getValue(TA);
2172       assert(RV && "Template argument record not found??");
2173       RV->print(OS, false);
2174     }
2175     OS << ">";
2176   }
2177
2178   OS << " {";
2179   ArrayRef<std::pair<Record *, SMRange>> SC = R.getSuperClasses();
2180   if (!SC.empty()) {
2181     OS << "\t//";
2182     for (const auto &SuperPair : SC)
2183       OS << " " << SuperPair.first->getNameInitAsString();
2184   }
2185   OS << "\n";
2186
2187   for (const RecordVal &Val : R.getValues())
2188     if (Val.getPrefix() && !R.isTemplateArg(Val.getNameInit()))
2189       OS << Val;
2190   for (const RecordVal &Val : R.getValues())
2191     if (!Val.getPrefix() && !R.isTemplateArg(Val.getNameInit()))
2192       OS << Val;
2193
2194   return OS << "}\n";
2195 }
2196
2197 Init *Record::getValueInit(StringRef FieldName) const {
2198   const RecordVal *R = getValue(FieldName);
2199   if (!R || !R->getValue())
2200     PrintFatalError(getLoc(), "Record `" + getName() +
2201       "' does not have a field named `" + FieldName + "'!\n");
2202   return R->getValue();
2203 }
2204
2205 StringRef Record::getValueAsString(StringRef FieldName) const {
2206   const RecordVal *R = getValue(FieldName);
2207   if (!R || !R->getValue())
2208     PrintFatalError(getLoc(), "Record `" + getName() +
2209       "' does not have a field named `" + FieldName + "'!\n");
2210
2211   if (StringInit *SI = dyn_cast<StringInit>(R->getValue()))
2212     return SI->getValue();
2213   if (CodeInit *CI = dyn_cast<CodeInit>(R->getValue()))
2214     return CI->getValue();
2215
2216   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2217     FieldName + "' does not have a string initializer!");
2218 }
2219
2220 BitsInit *Record::getValueAsBitsInit(StringRef FieldName) const {
2221   const RecordVal *R = getValue(FieldName);
2222   if (!R || !R->getValue())
2223     PrintFatalError(getLoc(), "Record `" + getName() +
2224       "' does not have a field named `" + FieldName + "'!\n");
2225
2226   if (BitsInit *BI = dyn_cast<BitsInit>(R->getValue()))
2227     return BI;
2228   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2229     FieldName + "' does not have a BitsInit initializer!");
2230 }
2231
2232 ListInit *Record::getValueAsListInit(StringRef FieldName) const {
2233   const RecordVal *R = getValue(FieldName);
2234   if (!R || !R->getValue())
2235     PrintFatalError(getLoc(), "Record `" + getName() +
2236       "' does not have a field named `" + FieldName + "'!\n");
2237
2238   if (ListInit *LI = dyn_cast<ListInit>(R->getValue()))
2239     return LI;
2240   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2241     FieldName + "' does not have a list initializer!");
2242 }
2243
2244 std::vector<Record*>
2245 Record::getValueAsListOfDefs(StringRef FieldName) const {
2246   ListInit *List = getValueAsListInit(FieldName);
2247   std::vector<Record*> Defs;
2248   for (Init *I : List->getValues()) {
2249     if (DefInit *DI = dyn_cast<DefInit>(I))
2250       Defs.push_back(DI->getDef());
2251     else
2252       PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2253         FieldName + "' list is not entirely DefInit!");
2254   }
2255   return Defs;
2256 }
2257
2258 int64_t Record::getValueAsInt(StringRef FieldName) const {
2259   const RecordVal *R = getValue(FieldName);
2260   if (!R || !R->getValue())
2261     PrintFatalError(getLoc(), "Record `" + getName() +
2262       "' does not have a field named `" + FieldName + "'!\n");
2263
2264   if (IntInit *II = dyn_cast<IntInit>(R->getValue()))
2265     return II->getValue();
2266   PrintFatalError(getLoc(), Twine("Record `") + getName() + "', field `" +
2267                                 FieldName +
2268                                 "' does not have an int initializer: " +
2269                                 R->getValue()->getAsString());
2270 }
2271
2272 std::vector<int64_t>
2273 Record::getValueAsListOfInts(StringRef FieldName) const {
2274   ListInit *List = getValueAsListInit(FieldName);
2275   std::vector<int64_t> Ints;
2276   for (Init *I : List->getValues()) {
2277     if (IntInit *II = dyn_cast<IntInit>(I))
2278       Ints.push_back(II->getValue());
2279     else
2280       PrintFatalError(getLoc(),
2281                       Twine("Record `") + getName() + "', field `" + FieldName +
2282                           "' does not have a list of ints initializer: " +
2283                           I->getAsString());
2284   }
2285   return Ints;
2286 }
2287
2288 std::vector<StringRef>
2289 Record::getValueAsListOfStrings(StringRef FieldName) const {
2290   ListInit *List = getValueAsListInit(FieldName);
2291   std::vector<StringRef> Strings;
2292   for (Init *I : List->getValues()) {
2293     if (StringInit *SI = dyn_cast<StringInit>(I))
2294       Strings.push_back(SI->getValue());
2295     else
2296       PrintFatalError(getLoc(),
2297                       Twine("Record `") + getName() + "', field `" + FieldName +
2298                           "' does not have a list of strings initializer: " +
2299                           I->getAsString());
2300   }
2301   return Strings;
2302 }
2303
2304 Record *Record::getValueAsDef(StringRef FieldName) const {
2305   const RecordVal *R = getValue(FieldName);
2306   if (!R || !R->getValue())
2307     PrintFatalError(getLoc(), "Record `" + getName() +
2308       "' does not have a field named `" + FieldName + "'!\n");
2309
2310   if (DefInit *DI = dyn_cast<DefInit>(R->getValue()))
2311     return DI->getDef();
2312   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2313     FieldName + "' does not have a def initializer!");
2314 }
2315
2316 Record *Record::getValueAsOptionalDef(StringRef FieldName) const {
2317   const RecordVal *R = getValue(FieldName);
2318   if (!R || !R->getValue())
2319     PrintFatalError(getLoc(), "Record `" + getName() +
2320       "' does not have a field named `" + FieldName + "'!\n");
2321
2322   if (DefInit *DI = dyn_cast<DefInit>(R->getValue()))
2323     return DI->getDef();
2324   if (isa<UnsetInit>(R->getValue()))
2325     return nullptr;
2326   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2327     FieldName + "' does not have either a def initializer or '?'!");
2328 }
2329
2330
2331 bool Record::getValueAsBit(StringRef FieldName) const {
2332   const RecordVal *R = getValue(FieldName);
2333   if (!R || !R->getValue())
2334     PrintFatalError(getLoc(), "Record `" + getName() +
2335       "' does not have a field named `" + FieldName + "'!\n");
2336
2337   if (BitInit *BI = dyn_cast<BitInit>(R->getValue()))
2338     return BI->getValue();
2339   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2340     FieldName + "' does not have a bit initializer!");
2341 }
2342
2343 bool Record::getValueAsBitOrUnset(StringRef FieldName, bool &Unset) const {
2344   const RecordVal *R = getValue(FieldName);
2345   if (!R || !R->getValue())
2346     PrintFatalError(getLoc(), "Record `" + getName() +
2347       "' does not have a field named `" + FieldName.str() + "'!\n");
2348
2349   if (isa<UnsetInit>(R->getValue())) {
2350     Unset = true;
2351     return false;
2352   }
2353   Unset = false;
2354   if (BitInit *BI = dyn_cast<BitInit>(R->getValue()))
2355     return BI->getValue();
2356   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2357     FieldName + "' does not have a bit initializer!");
2358 }
2359
2360 DagInit *Record::getValueAsDag(StringRef FieldName) const {
2361   const RecordVal *R = getValue(FieldName);
2362   if (!R || !R->getValue())
2363     PrintFatalError(getLoc(), "Record `" + getName() +
2364       "' does not have a field named `" + FieldName + "'!\n");
2365
2366   if (DagInit *DI = dyn_cast<DagInit>(R->getValue()))
2367     return DI;
2368   PrintFatalError(getLoc(), "Record `" + getName() + "', field `" +
2369     FieldName + "' does not have a dag initializer!");
2370 }
2371
2372 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
2373 LLVM_DUMP_METHOD void RecordKeeper::dump() const { errs() << *this; }
2374 #endif
2375
2376 raw_ostream &llvm::operator<<(raw_ostream &OS, const RecordKeeper &RK) {
2377   OS << "------------- Classes -----------------\n";
2378   for (const auto &C : RK.getClasses())
2379     OS << "class " << *C.second;
2380
2381   OS << "------------- Defs -----------------\n";
2382   for (const auto &D : RK.getDefs())
2383     OS << "def " << *D.second;
2384   return OS;
2385 }
2386
2387 /// GetNewAnonymousName - Generate a unique anonymous name that can be used as
2388 /// an identifier.
2389 Init *RecordKeeper::getNewAnonymousName() {
2390   return StringInit::get("anonymous_" + utostr(AnonCounter++));
2391 }
2392
2393 std::vector<Record *>
2394 RecordKeeper::getAllDerivedDefinitions(StringRef ClassName) const {
2395   Record *Class = getClass(ClassName);
2396   if (!Class)
2397     PrintFatalError("ERROR: Couldn't find the `" + ClassName + "' class!\n");
2398
2399   std::vector<Record*> Defs;
2400   for (const auto &D : getDefs())
2401     if (D.second->isSubClassOf(Class))
2402       Defs.push_back(D.second.get());
2403
2404   return Defs;
2405 }
2406
2407 Init *MapResolver::resolve(Init *VarName) {
2408   auto It = Map.find(VarName);
2409   if (It == Map.end())
2410     return nullptr;
2411
2412   Init *I = It->second.V;
2413
2414   if (!It->second.Resolved && Map.size() > 1) {
2415     // Resolve mutual references among the mapped variables, but prevent
2416     // infinite recursion.
2417     Map.erase(It);
2418     I = I->resolveReferences(*this);
2419     Map[VarName] = {I, true};
2420   }
2421
2422   return I;
2423 }
2424
2425 Init *RecordResolver::resolve(Init *VarName) {
2426   Init *Val = Cache.lookup(VarName);
2427   if (Val)
2428     return Val;
2429
2430   for (Init *S : Stack) {
2431     if (S == VarName)
2432       return nullptr; // prevent infinite recursion
2433   }
2434
2435   if (RecordVal *RV = getCurrentRecord()->getValue(VarName)) {
2436     if (!isa<UnsetInit>(RV->getValue())) {
2437       Val = RV->getValue();
2438       Stack.push_back(VarName);
2439       Val = Val->resolveReferences(*this);
2440       Stack.pop_back();
2441     }
2442   }
2443
2444   Cache[VarName] = Val;
2445   return Val;
2446 }
2447
2448 Init *TrackUnresolvedResolver::resolve(Init *VarName) {
2449   Init *I = nullptr;
2450
2451   if (R) {
2452     I = R->resolve(VarName);
2453     if (I && !FoundUnresolved) {
2454       // Do not recurse into the resolved initializer, as that would change
2455       // the behavior of the resolver we're delegating, but do check to see
2456       // if there are unresolved variables remaining.
2457       TrackUnresolvedResolver Sub;
2458       I->resolveReferences(Sub);
2459       FoundUnresolved |= Sub.FoundUnresolved;
2460     }
2461   }
2462
2463   if (!I)
2464     FoundUnresolved = true;
2465   return I;
2466 }
2467
2468 Init *HasReferenceResolver::resolve(Init *VarName)
2469 {
2470   if (VarName == VarNameToTrack)
2471     Found = true;
2472   return nullptr;
2473 }