lib/Analysis/DebugInfo.cpp

   1 //===--- DebugInfo.cpp - Debug Information Helper Classes -----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the helper classes used to build and interpret debug
  11 // information in LLVM IR form.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Analysis/DebugInfo.h"
  16 #include "llvm/Constants.h"
  17 #include "llvm/DerivedTypes.h"
  18 #include "llvm/Intrinsics.h"
  19 #include "llvm/IntrinsicInst.h"
  20 #include "llvm/Instructions.h"
  21 #include "llvm/LLVMContext.h"
  22 #include "llvm/Module.h"
  23 #include "llvm/Analysis/ValueTracking.h"
  24 #include "llvm/Support/Dwarf.h"
  25 #include "llvm/Support/DebugLoc.h"
  26 #include "llvm/Support/Streams.h"
  27
  28 using namespace llvm;
  29 using namespace llvm::dwarf;
  30
  31 //===----------------------------------------------------------------------===//
  32 // DIDescriptor
  33 //===----------------------------------------------------------------------===//
  34
  35 /// ValidDebugInfo - Return true if V represents valid debug info value.
  36 bool DIDescriptor::ValidDebugInfo(Value *V, CodeGenOpt::Level OptLevel) {
  37   if (!V)
  38     return false;
  39
  40   GlobalVariable *GV = dyn_cast<GlobalVariable>(V->stripPointerCasts());
  41   if (!GV)
  42     return false;
  43
  44   if (!GV->hasInternalLinkage () && !GV->hasLinkOnceLinkage())
  45     return false;
  46
  47   DIDescriptor DI(GV);
  48
  49   // Check current version. Allow Version6 for now.
  50   unsigned Version = DI.getVersion();
  51   if (Version != LLVMDebugVersion && Version != LLVMDebugVersion6)
  52     return false;
  53
  54   unsigned Tag = DI.getTag();
  55   switch (Tag) {
  56   case DW_TAG_variable:
  57     assert(DIVariable(GV).Verify() && "Invalid DebugInfo value");
  58     break;
  59   case DW_TAG_compile_unit:
  60     assert(DICompileUnit(GV).Verify() && "Invalid DebugInfo value");
  61     break;
  62   case DW_TAG_subprogram:
  63     assert(DISubprogram(GV).Verify() && "Invalid DebugInfo value");
  64     break;
  65   case DW_TAG_lexical_block:
  66     // FIXME: This interfers with the quality of generated code during
  67     // optimization.
  68     if (OptLevel != CodeGenOpt::None)
  69       return false;
  70     // FALLTHROUGH
  71   default:
  72     break;
  73   }
  74
  75   return true;
  76 }
  77
  78 DIDescriptor::DIDescriptor(GlobalVariable *GV, unsigned RequiredTag) {
  79   DbgGV = GV;
  80
  81   // If this is non-null, check to see if the Tag matches. If not, set to null.
  82   if (GV && getTag() != RequiredTag)
  83     DbgGV = 0;
  84 }
  85
  86 const std::string &
  87 DIDescriptor::getStringField(unsigned Elt, std::string &Result) const {
  88   if (DbgGV == 0) {
  89     Result.clear();
  90     return Result;
  91   }
  92
  93   Constant *C = DbgGV->getInitializer();
  94   if (C == 0 || Elt >= C->getNumOperands()) {
  95     Result.clear();
  96     return Result;
  97   }
  98
  99   // Fills in the string if it succeeds
 100   if (!GetConstantStringInfo(C->getOperand(Elt), Result))
 101     Result.clear();
 102
 103   return Result;
 104 }
 105
 106 uint64_t DIDescriptor::getUInt64Field(unsigned Elt) const {
 107   if (DbgGV == 0) return 0;
 108   if (!DbgGV->hasInitializer()) return 0;
 109
 110   Constant *C = DbgGV->getInitializer();
 111   if (C == 0 || Elt >= C->getNumOperands())
 112     return 0;
 113
 114   if (ConstantInt *CI = dyn_cast<ConstantInt>(C->getOperand(Elt)))
 115     return CI->getZExtValue();
 116   return 0;
 117 }
 118
 119 DIDescriptor DIDescriptor::getDescriptorField(unsigned Elt) const {
 120   if (DbgGV == 0) return DIDescriptor();
 121
 122   Constant *C = DbgGV->getInitializer();
 123   if (C == 0 || Elt >= C->getNumOperands())
 124     return DIDescriptor();
 125
 126   C = C->getOperand(Elt);
 127   return DIDescriptor(dyn_cast<GlobalVariable>(C->stripPointerCasts()));
 128 }
 129
 130 GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
 131   if (DbgGV == 0) return 0;
 132
 133   Constant *C = DbgGV->getInitializer();
 134   if (C == 0 || Elt >= C->getNumOperands())
 135     return 0;
 136
 137   C = C->getOperand(Elt);
 138   return dyn_cast<GlobalVariable>(C->stripPointerCasts());
 139 }
 140
 141 //===----------------------------------------------------------------------===//
 142 // Simple Descriptor Constructors and other Methods
 143 //===----------------------------------------------------------------------===//
 144
 145 // Needed by DIVariable::getType().
 146 DIType::DIType(GlobalVariable *GV) : DIDescriptor(GV) {
 147   if (!GV) return;
 148   unsigned tag = getTag();
 149   if (tag != dwarf::DW_TAG_base_type && !DIDerivedType::isDerivedType(tag) &&
 150       !DICompositeType::isCompositeType(tag))
 151     DbgGV = 0;
 152 }
 153
 154 /// isDerivedType - Return true if the specified tag is legal for
 155 /// DIDerivedType.
 156 bool DIType::isDerivedType(unsigned Tag) {
 157   switch (Tag) {
 158   case dwarf::DW_TAG_typedef:
 159   case dwarf::DW_TAG_pointer_type:
 160   case dwarf::DW_TAG_reference_type:
 161   case dwarf::DW_TAG_const_type:
 162   case dwarf::DW_TAG_volatile_type:
 163   case dwarf::DW_TAG_restrict_type:
 164   case dwarf::DW_TAG_member:
 165   case dwarf::DW_TAG_inheritance:
 166     return true;
 167   default:
 168     // FIXME: Even though it doesn't make sense, CompositeTypes are current
 169     // modelled as DerivedTypes, this should return true for them as well.
 170     return false;
 171   }
 172 }
 173
 174 /// isCompositeType - Return true if the specified tag is legal for
 175 /// DICompositeType.
 176 bool DIType::isCompositeType(unsigned TAG) {
 177   switch (TAG) {
 178   case dwarf::DW_TAG_array_type:
 179   case dwarf::DW_TAG_structure_type:
 180   case dwarf::DW_TAG_union_type:
 181   case dwarf::DW_TAG_enumeration_type:
 182   case dwarf::DW_TAG_vector_type:
 183   case dwarf::DW_TAG_subroutine_type:
 184   case dwarf::DW_TAG_class_type:
 185     return true;
 186   default:
 187     return false;
 188   }
 189 }
 190
 191 /// isVariable - Return true if the specified tag is legal for DIVariable.
 192 bool DIVariable::isVariable(unsigned Tag) {
 193   switch (Tag) {
 194   case dwarf::DW_TAG_auto_variable:
 195   case dwarf::DW_TAG_arg_variable:
 196   case dwarf::DW_TAG_return_variable:
 197     return true;
 198   default:
 199     return false;
 200   }
 201 }
 202
 203 unsigned DIArray::getNumElements() const {
 204   assert (DbgGV && "Invalid DIArray");
 205   Constant *C = DbgGV->getInitializer();
 206   assert (C && "Invalid DIArray initializer");
 207   return C->getNumOperands();
 208 }
 209
 210 /// replaceAllUsesWith - Replace all uses of debug info referenced by
 211 /// this descriptor. After this completes, the current debug info value
 212 /// is erased.
 213 void DIDerivedType::replaceAllUsesWith(DIDescriptor &D) {
 214   if (isNull())
 215     return;
 216
 217   assert (!D.isNull() && "Can not replace with null");
 218   getGV()->replaceAllUsesWith(D.getGV());
 219   getGV()->eraseFromParent();
 220 }
 221
 222 /// Verify - Verify that a compile unit is well formed.
 223 bool DICompileUnit::Verify() const {
 224   if (isNull())
 225     return false;
 226   std::string Res;
 227   if (getFilename(Res).empty())
 228     return false;
 229   // It is possible that directory and produce string is empty.
 230   return true;
 231 }
 232
 233 /// Verify - Verify that a type descriptor is well formed.
 234 bool DIType::Verify() const {
 235   if (isNull())
 236     return false;
 237   if (getContext().isNull())
 238     return false;
 239
 240   DICompileUnit CU = getCompileUnit();
 241   if (!CU.isNull() && !CU.Verify())
 242     return false;
 243   return true;
 244 }
 245
 246 /// Verify - Verify that a composite type descriptor is well formed.
 247 bool DICompositeType::Verify() const {
 248   if (isNull())
 249     return false;
 250   if (getContext().isNull())
 251     return false;
 252
 253   DICompileUnit CU = getCompileUnit();
 254   if (!CU.isNull() && !CU.Verify())
 255     return false;
 256   return true;
 257 }
 258
 259 /// Verify - Verify that a subprogram descriptor is well formed.
 260 bool DISubprogram::Verify() const {
 261   if (isNull())
 262     return false;
 263
 264   if (getContext().isNull())
 265     return false;
 266
 267   DICompileUnit CU = getCompileUnit();
 268   if (!CU.Verify())
 269     return false;
 270
 271   DICompositeType Ty = getType();
 272   if (!Ty.isNull() && !Ty.Verify())
 273     return false;
 274   return true;
 275 }
 276
 277 /// Verify - Verify that a global variable descriptor is well formed.
 278 bool DIGlobalVariable::Verify() const {
 279   if (isNull())
 280     return false;
 281
 282   if (getContext().isNull())
 283     return false;
 284
 285   DICompileUnit CU = getCompileUnit();
 286   if (!CU.isNull() && !CU.Verify())
 287     return false;
 288
 289   DIType Ty = getType();
 290   if (!Ty.Verify())
 291     return false;
 292
 293   if (!getGlobal())
 294     return false;
 295
 296   return true;
 297 }
 298
 299 /// Verify - Verify that a variable descriptor is well formed.
 300 bool DIVariable::Verify() const {
 301   if (isNull())
 302     return false;
 303
 304   if (getContext().isNull())
 305     return false;
 306
 307   DIType Ty = getType();
 308   if (!Ty.Verify())
 309     return false;
 310
 311   return true;
 312 }
 313
 314 /// getOriginalTypeSize - If this type is derived from a base type then
 315 /// return base type size.
 316 uint64_t DIDerivedType::getOriginalTypeSize() const {
 317   if (getTag() != dwarf::DW_TAG_member)
 318     return getSizeInBits();
 319   DIType BT = getTypeDerivedFrom();
 320   if (BT.getTag() != dwarf::DW_TAG_base_type)
 321     return getSizeInBits();
 322   return BT.getSizeInBits();
 323 }
 324
 325 /// describes - Return true if this subprogram provides debugging
 326 /// information for the function F.
 327 bool DISubprogram::describes(const Function *F) {
 328   assert (F && "Invalid function");
 329   std::string Name;
 330   getLinkageName(Name);
 331   if (Name.empty())
 332     getName(Name);
 333   if (F->getName() == Name)
 334     return true;
 335   return false;
 336 }
 337
 338 //===----------------------------------------------------------------------===//
 339 // DIDescriptor: dump routines for all descriptors.
 340 //===----------------------------------------------------------------------===//
 341
 342
 343 /// dump - Print descriptor.
 344 void DIDescriptor::dump() const {
 345   cerr << "[" << dwarf::TagString(getTag()) << "] ";
 346   cerr << std::hex << "[GV:" << DbgGV << "]" << std::dec;
 347 }
 348
 349 /// dump - Print compile unit.
 350 void DICompileUnit::dump() const {
 351   if (getLanguage())
 352     cerr << " [" << dwarf::LanguageString(getLanguage()) << "] ";
 353
 354   std::string Res1, Res2;
 355   cerr << " [" << getDirectory(Res1) << "/" << getFilename(Res2) << " ]";
 356 }
 357
 358 /// dump - Print type.
 359 void DIType::dump() const {
 360   if (isNull()) return;
 361
 362   std::string Res;
 363   if (!getName(Res).empty())
 364     cerr << " [" << Res << "] ";
 365
 366   unsigned Tag = getTag();
 367   cerr << " [" << dwarf::TagString(Tag) << "] ";
 368
 369   // TODO : Print context
 370   getCompileUnit().dump();
 371   cerr << " ["
 372        << getLineNumber() << ", "
 373        << getSizeInBits() << ", "
 374        << getAlignInBits() << ", "
 375        << getOffsetInBits()
 376        << "] ";
 377
 378   if (isPrivate())
 379     cerr << " [private] ";
 380   else if (isProtected())
 381     cerr << " [protected] ";
 382
 383   if (isForwardDecl())
 384     cerr << " [fwd] ";
 385
 386   if (isBasicType(Tag))
 387     DIBasicType(DbgGV).dump();
 388   else if (isDerivedType(Tag))
 389     DIDerivedType(DbgGV).dump();
 390   else if (isCompositeType(Tag))
 391     DICompositeType(DbgGV).dump();
 392   else {
 393     cerr << "Invalid DIType\n";
 394     return;
 395   }
 396
 397   cerr << "\n";
 398 }
 399
 400 /// dump - Print basic type.
 401 void DIBasicType::dump() const {
 402   cerr << " [" << dwarf::AttributeEncodingString(getEncoding()) << "] ";
 403 }
 404
 405 /// dump - Print derived type.
 406 void DIDerivedType::dump() const {
 407   cerr << "\n\t Derived From: "; getTypeDerivedFrom().dump();
 408 }
 409
 410 /// dump - Print composite type.
 411 void DICompositeType::dump() const {
 412   DIArray A = getTypeArray();
 413   if (A.isNull())
 414     return;
 415   cerr << " [" << A.getNumElements() << " elements]";
 416 }
 417
 418 /// dump - Print global.
 419 void DIGlobal::dump() const {
 420   std::string Res;
 421   if (!getName(Res).empty())
 422     cerr << " [" << Res << "] ";
 423
 424   unsigned Tag = getTag();
 425   cerr << " [" << dwarf::TagString(Tag) << "] ";
 426
 427   // TODO : Print context
 428   getCompileUnit().dump();
 429   cerr << " [" << getLineNumber() << "] ";
 430
 431   if (isLocalToUnit())
 432     cerr << " [local] ";
 433
 434   if (isDefinition())
 435     cerr << " [def] ";
 436
 437   if (isGlobalVariable(Tag))
 438     DIGlobalVariable(DbgGV).dump();
 439
 440   cerr << "\n";
 441 }
 442
 443 /// dump - Print subprogram.
 444 void DISubprogram::dump() const {
 445   DIGlobal::dump();
 446 }
 447
 448 /// dump - Print global variable.
 449 void DIGlobalVariable::dump() const {
 450   cerr << " ["; getGlobal()->dump(); cerr << "] ";
 451 }
 452
 453 /// dump - Print variable.
 454 void DIVariable::dump() const {
 455   std::string Res;
 456   if (!getName(Res).empty())
 457     cerr << " [" << Res << "] ";
 458
 459   getCompileUnit().dump();
 460   cerr << " [" << getLineNumber() << "] ";
 461   getType().dump();
 462   cerr << "\n";
 463 }
 464
 465 //===----------------------------------------------------------------------===//
 466 // DIFactory: Basic Helpers
 467 //===----------------------------------------------------------------------===//
 468
 469 DIFactory::DIFactory(Module &m)
 470   : M(m), VMContext(M.getContext()), StopPointFn(0), FuncStartFn(0),
 471     RegionStartFn(0), RegionEndFn(0),
 472     DeclareFn(0) {
 473   EmptyStructPtr = VMContext.getPointerTypeUnqual(VMContext.getStructType());
 474 }
 475
 476 /// getCastToEmpty - Return this descriptor as a Constant* with type '{}*'.
 477 /// This is only valid when the descriptor is non-null.
 478 Constant *DIFactory::getCastToEmpty(DIDescriptor D) {
 479   if (D.isNull()) return VMContext.getNullValue(EmptyStructPtr);
 480   return ConstantExpr::getBitCast(D.getGV(), EmptyStructPtr);
 481 }
 482
 483 Constant *DIFactory::GetTagConstant(unsigned TAG) {
 484   assert((TAG & LLVMDebugVersionMask) == 0 &&
 485          "Tag too large for debug encoding!");
 486   return ConstantInt::get(Type::Int32Ty, TAG | LLVMDebugVersion);
 487 }
 488
 489 Constant *DIFactory::GetStringConstant(const std::string &String) {
 490   // Check string cache for previous edition.
 491   Constant *&Slot = StringCache[String];
 492
 493   // Return Constant if previously defined.
 494   if (Slot) return Slot;
 495
 496   const PointerType *DestTy = VMContext.getPointerTypeUnqual(Type::Int8Ty);
 497
 498   // If empty string then use a i8* null instead.
 499   if (String.empty())
 500     return Slot = VMContext.getConstantPointerNull(DestTy);
 501
 502   // Construct string as an llvm constant.
 503   Constant *ConstStr = ConstantArray::get(String);
 504
 505   // Otherwise create and return a new string global.
 506   GlobalVariable *StrGV = new GlobalVariable(M, ConstStr->getType(), true,
 507                                              GlobalVariable::InternalLinkage,
 508                                              ConstStr, ".str");
 509   StrGV->setSection("llvm.metadata");
 510   return Slot = ConstantExpr::getBitCast(StrGV, DestTy);
 511 }
 512
 513 //===----------------------------------------------------------------------===//
 514 // DIFactory: Primary Constructors
 515 //===----------------------------------------------------------------------===//
 516
 517 /// GetOrCreateArray - Create an descriptor for an array of descriptors.
 518 /// This implicitly uniques the arrays created.
 519 DIArray DIFactory::GetOrCreateArray(DIDescriptor *Tys, unsigned NumTys) {
 520   SmallVector<Constant*, 16> Elts;
 521
 522   for (unsigned i = 0; i != NumTys; ++i)
 523     Elts.push_back(getCastToEmpty(Tys[i]));
 524
 525   Constant *Init = ConstantArray::get(VMContext.getArrayType(EmptyStructPtr,
 526                                                      Elts.size()),
 527                                       Elts.data(), Elts.size());
 528   // If we already have this array, just return the uniqued version.
 529   DIDescriptor &Entry = SimpleConstantCache[Init];
 530   if (!Entry.isNull()) return DIArray(Entry.getGV());
 531
 532   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 533                                           GlobalValue::InternalLinkage,
 534                                           Init, "llvm.dbg.array");
 535   GV->setSection("llvm.metadata");
 536   Entry = DIDescriptor(GV);
 537   return DIArray(GV);
 538 }
 539
 540 /// GetOrCreateSubrange - Create a descriptor for a value range.  This
 541 /// implicitly uniques the values returned.
 542 DISubrange DIFactory::GetOrCreateSubrange(int64_t Lo, int64_t Hi) {
 543   Constant *Elts[] = {
 544     GetTagConstant(dwarf::DW_TAG_subrange_type),
 545     ConstantInt::get(Type::Int64Ty, Lo),
 546     ConstantInt::get(Type::Int64Ty, Hi)
 547   };
 548
 549   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 550
 551   // If we already have this range, just return the uniqued version.
 552   DIDescriptor &Entry = SimpleConstantCache[Init];
 553   if (!Entry.isNull()) return DISubrange(Entry.getGV());
 554
 555   M.addTypeName("llvm.dbg.subrange.type", Init->getType());
 556
 557   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 558                                           GlobalValue::InternalLinkage,
 559                                           Init, "llvm.dbg.subrange");
 560   GV->setSection("llvm.metadata");
 561   Entry = DIDescriptor(GV);
 562   return DISubrange(GV);
 563 }
 564
 565
 566
 567 /// CreateCompileUnit - Create a new descriptor for the specified compile
 568 /// unit.  Note that this does not unique compile units within the module.
 569 DICompileUnit DIFactory::CreateCompileUnit(unsigned LangID,
 570                                            const std::string &Filename,
 571                                            const std::string &Directory,
 572                                            const std::string &Producer,
 573                                            bool isMain,
 574                                            bool isOptimized,
 575                                            const char *Flags,
 576                                            unsigned RunTimeVer) {
 577   Constant *Elts[] = {
 578     GetTagConstant(dwarf::DW_TAG_compile_unit),
 579     VMContext.getNullValue(EmptyStructPtr),
 580     ConstantInt::get(Type::Int32Ty, LangID),
 581     GetStringConstant(Filename),
 582     GetStringConstant(Directory),
 583     GetStringConstant(Producer),
 584     ConstantInt::get(Type::Int1Ty, isMain),
 585     ConstantInt::get(Type::Int1Ty, isOptimized),
 586     GetStringConstant(Flags),
 587     ConstantInt::get(Type::Int32Ty, RunTimeVer)
 588   };
 589
 590   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 591
 592   M.addTypeName("llvm.dbg.compile_unit.type", Init->getType());
 593   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 594                                           GlobalValue::LinkOnceAnyLinkage,
 595                                           Init, "llvm.dbg.compile_unit");
 596   GV->setSection("llvm.metadata");
 597   return DICompileUnit(GV);
 598 }
 599
 600 /// CreateEnumerator - Create a single enumerator value.
 601 DIEnumerator DIFactory::CreateEnumerator(const std::string &Name, uint64_t Val){
 602   Constant *Elts[] = {
 603     GetTagConstant(dwarf::DW_TAG_enumerator),
 604     GetStringConstant(Name),
 605     ConstantInt::get(Type::Int64Ty, Val)
 606   };
 607
 608   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 609
 610   M.addTypeName("llvm.dbg.enumerator.type", Init->getType());
 611   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 612                                           GlobalValue::InternalLinkage,
 613                                           Init, "llvm.dbg.enumerator");
 614   GV->setSection("llvm.metadata");
 615   return DIEnumerator(GV);
 616 }
 617
 618
 619 /// CreateBasicType - Create a basic type like int, float, etc.
 620 DIBasicType DIFactory::CreateBasicType(DIDescriptor Context,
 621                                       const std::string &Name,
 622                                        DICompileUnit CompileUnit,
 623                                        unsigned LineNumber,
 624                                        uint64_t SizeInBits,
 625                                        uint64_t AlignInBits,
 626                                        uint64_t OffsetInBits, unsigned Flags,
 627                                        unsigned Encoding) {
 628   Constant *Elts[] = {
 629     GetTagConstant(dwarf::DW_TAG_base_type),
 630     getCastToEmpty(Context),
 631     GetStringConstant(Name),
 632     getCastToEmpty(CompileUnit),
 633     ConstantInt::get(Type::Int32Ty, LineNumber),
 634     ConstantInt::get(Type::Int64Ty, SizeInBits),
 635     ConstantInt::get(Type::Int64Ty, AlignInBits),
 636     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 637     ConstantInt::get(Type::Int32Ty, Flags),
 638     ConstantInt::get(Type::Int32Ty, Encoding)
 639   };
 640
 641   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 642
 643   M.addTypeName("llvm.dbg.basictype.type", Init->getType());
 644   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 645                                           GlobalValue::InternalLinkage,
 646                                           Init, "llvm.dbg.basictype");
 647   GV->setSection("llvm.metadata");
 648   return DIBasicType(GV);
 649 }
 650
 651 /// CreateDerivedType - Create a derived type like const qualified type,
 652 /// pointer, typedef, etc.
 653 DIDerivedType DIFactory::CreateDerivedType(unsigned Tag,
 654                                            DIDescriptor Context,
 655                                            const std::string &Name,
 656                                            DICompileUnit CompileUnit,
 657                                            unsigned LineNumber,
 658                                            uint64_t SizeInBits,
 659                                            uint64_t AlignInBits,
 660                                            uint64_t OffsetInBits,
 661                                            unsigned Flags,
 662                                            DIType DerivedFrom) {
 663   Constant *Elts[] = {
 664     GetTagConstant(Tag),
 665     getCastToEmpty(Context),
 666     GetStringConstant(Name),
 667     getCastToEmpty(CompileUnit),
 668     ConstantInt::get(Type::Int32Ty, LineNumber),
 669     ConstantInt::get(Type::Int64Ty, SizeInBits),
 670     ConstantInt::get(Type::Int64Ty, AlignInBits),
 671     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 672     ConstantInt::get(Type::Int32Ty, Flags),
 673     getCastToEmpty(DerivedFrom)
 674   };
 675
 676   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 677
 678   M.addTypeName("llvm.dbg.derivedtype.type", Init->getType());
 679   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 680                                           GlobalValue::InternalLinkage,
 681                                           Init, "llvm.dbg.derivedtype");
 682   GV->setSection("llvm.metadata");
 683   return DIDerivedType(GV);
 684 }
 685
 686 /// CreateCompositeType - Create a composite type like array, struct, etc.
 687 DICompositeType DIFactory::CreateCompositeType(unsigned Tag,
 688                                                DIDescriptor Context,
 689                                                const std::string &Name,
 690                                                DICompileUnit CompileUnit,
 691                                                unsigned LineNumber,
 692                                                uint64_t SizeInBits,
 693                                                uint64_t AlignInBits,
 694                                                uint64_t OffsetInBits,
 695                                                unsigned Flags,
 696                                                DIType DerivedFrom,
 697                                                DIArray Elements,
 698                                                unsigned RuntimeLang) {
 699
 700   Constant *Elts[] = {
 701     GetTagConstant(Tag),
 702     getCastToEmpty(Context),
 703     GetStringConstant(Name),
 704     getCastToEmpty(CompileUnit),
 705     ConstantInt::get(Type::Int32Ty, LineNumber),
 706     ConstantInt::get(Type::Int64Ty, SizeInBits),
 707     ConstantInt::get(Type::Int64Ty, AlignInBits),
 708     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 709     ConstantInt::get(Type::Int32Ty, Flags),
 710     getCastToEmpty(DerivedFrom),
 711     getCastToEmpty(Elements),
 712     ConstantInt::get(Type::Int32Ty, RuntimeLang)
 713   };
 714
 715   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 716
 717   M.addTypeName("llvm.dbg.composite.type", Init->getType());
 718   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 719                                           GlobalValue::InternalLinkage,
 720                                           Init, "llvm.dbg.composite");
 721   GV->setSection("llvm.metadata");
 722   return DICompositeType(GV);
 723 }
 724
 725
 726 /// CreateSubprogram - Create a new descriptor for the specified subprogram.
 727 /// See comments in DISubprogram for descriptions of these fields.  This
 728 /// method does not unique the generated descriptors.
 729 DISubprogram DIFactory::CreateSubprogram(DIDescriptor Context,
 730                                          const std::string &Name,
 731                                          const std::string &DisplayName,
 732                                          const std::string &LinkageName,
 733                                          DICompileUnit CompileUnit,
 734                                          unsigned LineNo, DIType Type,
 735                                          bool isLocalToUnit,
 736                                          bool isDefinition) {
 737
 738   Constant *Elts[] = {
 739     GetTagConstant(dwarf::DW_TAG_subprogram),
 740     VMContext.getNullValue(EmptyStructPtr),
 741     getCastToEmpty(Context),
 742     GetStringConstant(Name),
 743     GetStringConstant(DisplayName),
 744     GetStringConstant(LinkageName),
 745     getCastToEmpty(CompileUnit),
 746     ConstantInt::get(Type::Int32Ty, LineNo),
 747     getCastToEmpty(Type),
 748     ConstantInt::get(Type::Int1Ty, isLocalToUnit),
 749     ConstantInt::get(Type::Int1Ty, isDefinition)
 750   };
 751
 752   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 753
 754   M.addTypeName("llvm.dbg.subprogram.type", Init->getType());
 755   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 756                                           GlobalValue::LinkOnceAnyLinkage,
 757                                           Init, "llvm.dbg.subprogram");
 758   GV->setSection("llvm.metadata");
 759   return DISubprogram(GV);
 760 }
 761
 762 /// CreateGlobalVariable - Create a new descriptor for the specified global.
 763 DIGlobalVariable
 764 DIFactory::CreateGlobalVariable(DIDescriptor Context, const std::string &Name,
 765                                 const std::string &DisplayName,
 766                                 const std::string &LinkageName,
 767                                 DICompileUnit CompileUnit,
 768                                 unsigned LineNo, DIType Type,bool isLocalToUnit,
 769                                 bool isDefinition, llvm::GlobalVariable *Val) {
 770   Constant *Elts[] = {
 771     GetTagConstant(dwarf::DW_TAG_variable),
 772     VMContext.getNullValue(EmptyStructPtr),
 773     getCastToEmpty(Context),
 774     GetStringConstant(Name),
 775     GetStringConstant(DisplayName),
 776     GetStringConstant(LinkageName),
 777     getCastToEmpty(CompileUnit),
 778     ConstantInt::get(Type::Int32Ty, LineNo),
 779     getCastToEmpty(Type),
 780     ConstantInt::get(Type::Int1Ty, isLocalToUnit),
 781     ConstantInt::get(Type::Int1Ty, isDefinition),
 782     ConstantExpr::getBitCast(Val, EmptyStructPtr)
 783   };
 784
 785   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 786
 787   M.addTypeName("llvm.dbg.global_variable.type", Init->getType());
 788   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 789                                           GlobalValue::LinkOnceAnyLinkage,
 790                                           Init, "llvm.dbg.global_variable");
 791   GV->setSection("llvm.metadata");
 792   return DIGlobalVariable(GV);
 793 }
 794
 795
 796 /// CreateVariable - Create a new descriptor for the specified variable.
 797 DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
 798                                      const std::string &Name,
 799                                      DICompileUnit CompileUnit, unsigned LineNo,
 800                                      DIType Type) {
 801   Constant *Elts[] = {
 802     GetTagConstant(Tag),
 803     getCastToEmpty(Context),
 804     GetStringConstant(Name),
 805     getCastToEmpty(CompileUnit),
 806     ConstantInt::get(Type::Int32Ty, LineNo),
 807     getCastToEmpty(Type)
 808   };
 809
 810   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 811
 812   M.addTypeName("llvm.dbg.variable.type", Init->getType());
 813   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 814                                           GlobalValue::InternalLinkage,
 815                                           Init, "llvm.dbg.variable");
 816   GV->setSection("llvm.metadata");
 817   return DIVariable(GV);
 818 }
 819
 820
 821 /// CreateBlock - This creates a descriptor for a lexical block with the
 822 /// specified parent VMContext.
 823 DIBlock DIFactory::CreateBlock(DIDescriptor Context) {
 824   Constant *Elts[] = {
 825     GetTagConstant(dwarf::DW_TAG_lexical_block),
 826     getCastToEmpty(Context)
 827   };
 828
 829   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 830
 831   M.addTypeName("llvm.dbg.block.type", Init->getType());
 832   GlobalVariable *GV = new GlobalVariable(M, Init->getType(), true,
 833                                           GlobalValue::InternalLinkage,
 834                                           Init, "llvm.dbg.block");
 835   GV->setSection("llvm.metadata");
 836   return DIBlock(GV);
 837 }
 838
 839
 840 //===----------------------------------------------------------------------===//
 841 // DIFactory: Routines for inserting code into a function
 842 //===----------------------------------------------------------------------===//
 843
 844 /// InsertStopPoint - Create a new llvm.dbg.stoppoint intrinsic invocation,
 845 /// inserting it at the end of the specified basic block.
 846 void DIFactory::InsertStopPoint(DICompileUnit CU, unsigned LineNo,
 847                                 unsigned ColNo, BasicBlock *BB) {
 848
 849   // Lazily construct llvm.dbg.stoppoint function.
 850   if (!StopPointFn)
 851     StopPointFn = llvm::Intrinsic::getDeclaration(&M,
 852                                               llvm::Intrinsic::dbg_stoppoint);
 853
 854   // Invoke llvm.dbg.stoppoint
 855   Value *Args[] = {
 856     ConstantInt::get(llvm::Type::Int32Ty, LineNo),
 857     ConstantInt::get(llvm::Type::Int32Ty, ColNo),
 858     getCastToEmpty(CU)
 859   };
 860   CallInst::Create(StopPointFn, Args, Args+3, "", BB);
 861 }
 862
 863 /// InsertSubprogramStart - Create a new llvm.dbg.func.start intrinsic to
 864 /// mark the start of the specified subprogram.
 865 void DIFactory::InsertSubprogramStart(DISubprogram SP, BasicBlock *BB) {
 866   // Lazily construct llvm.dbg.func.start.
 867   if (!FuncStartFn)
 868     FuncStartFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_func_start);
 869
 870   // Call llvm.dbg.func.start which also implicitly sets a stoppoint.
 871   CallInst::Create(FuncStartFn, getCastToEmpty(SP), "", BB);
 872 }
 873
 874 /// InsertRegionStart - Insert a new llvm.dbg.region.start intrinsic call to
 875 /// mark the start of a region for the specified scoping descriptor.
 876 void DIFactory::InsertRegionStart(DIDescriptor D, BasicBlock *BB) {
 877   // Lazily construct llvm.dbg.region.start function.
 878   if (!RegionStartFn)
 879     RegionStartFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_region_start);
 880
 881   // Call llvm.dbg.func.start.
 882   CallInst::Create(RegionStartFn, getCastToEmpty(D), "", BB);
 883 }
 884
 885 /// InsertRegionEnd - Insert a new llvm.dbg.region.end intrinsic call to
 886 /// mark the end of a region for the specified scoping descriptor.
 887 void DIFactory::InsertRegionEnd(DIDescriptor D, BasicBlock *BB) {
 888   // Lazily construct llvm.dbg.region.end function.
 889   if (!RegionEndFn)
 890     RegionEndFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_region_end);
 891
 892   // Call llvm.dbg.region.end.
 893   CallInst::Create(RegionEndFn, getCastToEmpty(D), "", BB);
 894 }
 895
 896 /// InsertDeclare - Insert a new llvm.dbg.declare intrinsic call.
 897 void DIFactory::InsertDeclare(Value *Storage, DIVariable D, BasicBlock *BB) {
 898   // Cast the storage to a {}* for the call to llvm.dbg.declare.
 899   Storage = new BitCastInst(Storage, EmptyStructPtr, "", BB);
 900
 901   if (!DeclareFn)
 902     DeclareFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
 903
 904   Value *Args[] = { Storage, getCastToEmpty(D) };
 905   CallInst::Create(DeclareFn, Args, Args+2, "", BB);
 906 }
 907
 908 //===----------------------------------------------------------------------===//
 909 // DebugInfoEnumerator implementations.
 910 //===----------------------------------------------------------------------===//
 911
 912 /// enumerateModule - Enumerate entire module and collect debug info.
 913 void DebugInfoEnumerator::enumerateModule(Module &M) {
 914
 915   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
 916     for (Function::iterator FI = (*I).begin(), FE = (*I).end(); FI != FE; ++FI)
 917       for (BasicBlock::iterator BI = (*FI).begin(), BE = (*FI).end(); BI != BE;
 918            ++BI) {
 919         if (DbgStopPointInst *SPI = dyn_cast<DbgStopPointInst>(BI))
 920           enumerateStopPoint(SPI);
 921         else if (DbgFuncStartInst *FSI = dyn_cast<DbgFuncStartInst>(BI))
 922           enumerateFuncStart(FSI);
 923       }
 924
 925   for (Module::global_iterator GVI = M.global_begin(), GVE = M.global_end();
 926        GVI != GVE; ++GVI) {
 927     GlobalVariable *GV = GVI;
 928     if (!GV->hasName() || !GV->isConstant()
 929         || strcmp(GV->getName().data(), "llvm.dbg.global_variable")
 930         || !GV->hasInitializer())
 931       continue;
 932     DIGlobalVariable DIG(GV);
 933     if (addGlobalVariable(DIG)) {
 934       addCompileUnit(DIG.getCompileUnit());
 935       enumerateType(DIG.getType());
 936     }
 937   }
 938 }
 939
 940 /// enumerateType - Enumerate DIType.
 941 void DebugInfoEnumerator::enumerateType(DIType DT) {
 942   if (DT.isNull())
 943     return;
 944   if (!NodesSeen.insert(DT.getGV()))
 945     return;
 946
 947   addCompileUnit(DT.getCompileUnit());
 948   if (DT.isCompositeType(DT.getTag())) {
 949     DICompositeType DCT(DT.getGV());
 950     enumerateType(DCT.getTypeDerivedFrom());
 951     DIArray DA = DCT.getTypeArray();
 952     if (!DA.isNull())
 953       for (unsigned i = 0, e = DA.getNumElements(); i != e; ++i) {
 954         DIDescriptor D = DA.getElement(i);
 955         DIType TypeE = DIType(D.getGV());
 956         if (!TypeE.isNull())
 957           enumerateType(TypeE);
 958         else
 959           enumerateSubprogram(DISubprogram(D.getGV()));
 960       }
 961   } else if (DT.isDerivedType(DT.getTag())) {
 962     DIDerivedType DDT(DT.getGV());
 963     if (!DDT.isNull())
 964       enumerateType(DDT.getTypeDerivedFrom());
 965   }
 966 }
 967
 968 /// enumerateSubprogram - Enumberate DISubprogram.
 969 void DebugInfoEnumerator::enumerateSubprogram(DISubprogram SP) {
 970   if (!addSubprogram(SP))
 971     return;
 972   addCompileUnit(SP.getCompileUnit());
 973   enumerateType(SP.getType());
 974 }
 975
 976 /// enumerateStopPoint - Enumerate DbgStopPointInst.
 977 void DebugInfoEnumerator::enumerateStopPoint(DbgStopPointInst *SPI) {
 978   GlobalVariable *Context = dyn_cast<GlobalVariable>(SPI->getContext());
 979   addCompileUnit(DICompileUnit(Context));
 980 }
 981
 982 /// enumerateFuncStart - Enumberate DbgFuncStartInst.
 983 void DebugInfoEnumerator::enumerateFuncStart(DbgFuncStartInst *FSI) {
 984   GlobalVariable *SP = dyn_cast<GlobalVariable>(FSI->getSubprogram());
 985   enumerateSubprogram(DISubprogram(SP));
 986 }
 987
 988 /// addCompileUnit - Add compile unit into CUs.
 989 bool DebugInfoEnumerator::addCompileUnit(DICompileUnit CU) {
 990   if (CU.isNull())
 991     return false;
 992
 993   if (!NodesSeen.insert(CU.getGV()))
 994     return false;
 995
 996   CUs.push_back(CU.getGV());
 997   return true;
 998 }
 999
1000 /// addGlobalVariable - Add global variable into GVs.
1001 bool DebugInfoEnumerator::addGlobalVariable(DIGlobalVariable DIG) {
1002   if (DIG.isNull())
1003     return false;
1004
1005   if (!NodesSeen.insert(DIG.getGV()))
1006     return false;
1007
1008   GVs.push_back(DIG.getGV());
1009   return true;
1010 }
1011
1012 // addSubprogram - Add subprgoram into SPs.
1013 bool DebugInfoEnumerator::addSubprogram(DISubprogram SP) {
1014   if (SP.isNull())
1015     return false;
1016
1017   if (!NodesSeen.insert(SP.getGV()))
1018     return false;
1019
1020   SPs.push_back(SP.getGV());
1021   return true;
1022 }
1023
1024 namespace llvm {
1025   /// findStopPoint - Find the stoppoint coressponding to this instruction, that
1026   /// is the stoppoint that dominates this instruction.
1027   const DbgStopPointInst *findStopPoint(const Instruction *Inst) {
1028     if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(Inst))
1029       return DSI;
1030
1031     const BasicBlock *BB = Inst->getParent();
1032     BasicBlock::const_iterator I = Inst, B;
1033     while (BB) {
1034       B = BB->begin();
1035
1036       // A BB consisting only of a terminator can't have a stoppoint.
1037       while (I != B) {
1038         --I;
1039         if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(I))
1040           return DSI;
1041       }
1042
1043       // This BB didn't have a stoppoint: if there is only one predecessor, look
1044       // for a stoppoint there. We could use getIDom(), but that would require
1045       // dominator info.
1046       BB = I->getParent()->getUniquePredecessor();
1047       if (BB)
1048         I = BB->getTerminator();
1049     }
1050
1051     return 0;
1052   }
1053
1054   /// findBBStopPoint - Find the stoppoint corresponding to first real
1055   /// (non-debug intrinsic) instruction in this Basic Block, and return the
1056   /// stoppoint for it.
1057   const DbgStopPointInst *findBBStopPoint(const BasicBlock *BB) {
1058     for(BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
1059       if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(I))
1060         return DSI;
1061
1062     // Fallback to looking for stoppoint of unique predecessor. Useful if this
1063     // BB contains no stoppoints, but unique predecessor does.
1064     BB = BB->getUniquePredecessor();
1065     if (BB)
1066       return findStopPoint(BB->getTerminator());
1067
1068     return 0;
1069   }
1070
1071   Value *findDbgGlobalDeclare(GlobalVariable *V) {
1072     const Module *M = V->getParent();
1073     LLVMContext& Context = M->getContext();
1074
1075     const Type *Ty = M->getTypeByName("llvm.dbg.global_variable.type");
1076     if (!Ty) return 0;
1077
1078     Ty = Context.getPointerType(Ty, 0);
1079
1080     Value *Val = V->stripPointerCasts();
1081     for (Value::use_iterator I = Val->use_begin(), E = Val->use_end();
1082          I != E; ++I) {
1083       if (ConstantExpr *CE = dyn_cast<ConstantExpr>(I)) {
1084         if (CE->getOpcode() == Instruction::BitCast) {
1085           Value *VV = CE;
1086
1087           while (VV->hasOneUse())
1088             VV = *VV->use_begin();
1089
1090           if (VV->getType() == Ty)
1091             return VV;
1092         }
1093       }
1094     }
1095
1096     if (Val->getType() == Ty)
1097       return Val;
1098
1099     return 0;
1100   }
1101
1102   /// Finds the llvm.dbg.declare intrinsic corresponding to this value if any.
1103   /// It looks through pointer casts too.
1104   const DbgDeclareInst *findDbgDeclare(const Value *V, bool stripCasts) {
1105     if (stripCasts) {
1106       V = V->stripPointerCasts();
1107
1108       // Look for the bitcast.
1109       for (Value::use_const_iterator I = V->use_begin(), E =V->use_end();
1110             I != E; ++I)
1111         if (isa<BitCastInst>(I))
1112           return findDbgDeclare(*I, false);
1113
1114       return 0;
1115     }
1116
1117     // Find llvm.dbg.declare among uses of the instruction.
1118     for (Value::use_const_iterator I = V->use_begin(), E =V->use_end();
1119           I != E; ++I)
1120       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I))
1121         return DDI;
1122
1123     return 0;
1124   }
1125
1126   bool getLocationInfo(const Value *V, std::string &DisplayName,
1127                        std::string &Type, unsigned &LineNo, std::string &File,
1128                        std::string &Dir) {
1129     DICompileUnit Unit;
1130     DIType TypeD;
1131
1132     if (GlobalVariable *GV = dyn_cast<GlobalVariable>(const_cast<Value*>(V))) {
1133       Value *DIGV = findDbgGlobalDeclare(GV);
1134       if (!DIGV) return false;
1135       DIGlobalVariable Var(cast<GlobalVariable>(DIGV));
1136
1137       Var.getDisplayName(DisplayName);
1138       LineNo = Var.getLineNumber();
1139       Unit = Var.getCompileUnit();
1140       TypeD = Var.getType();
1141     } else {
1142       const DbgDeclareInst *DDI = findDbgDeclare(V);
1143       if (!DDI) return false;
1144       DIVariable Var(cast<GlobalVariable>(DDI->getVariable()));
1145
1146       Var.getName(DisplayName);
1147       LineNo = Var.getLineNumber();
1148       Unit = Var.getCompileUnit();
1149       TypeD = Var.getType();
1150     }
1151
1152     TypeD.getName(Type);
1153     Unit.getFilename(File);
1154     Unit.getDirectory(Dir);
1155     return true;
1156   }
1157
1158   /// CollectDebugInfoAnchors - Collect debugging information anchors.
1159   void CollectDebugInfoAnchors(Module &M,
1160                                SmallVector<GlobalVariable *, 2> &CUs,
1161                                SmallVector<GlobalVariable *, 4> &GVs,
1162                                SmallVector<GlobalVariable *, 4> &SPs) {
1163
1164     for (Module::global_iterator GVI = M.global_begin(), E = M.global_end();
1165        GVI != E; GVI++) {
1166       GlobalVariable *GV = GVI;
1167       if (GV->hasName() && GV->getName().startswith("llvm.dbg")
1168           && GV->isConstant() && GV->hasInitializer()) {
1169         DICompileUnit C(GV);
1170         if (C.isNull() == false) {
1171           CUs.push_back(GV);
1172           continue;
1173         }
1174         DIGlobalVariable G(GV);
1175         if (G.isNull() == false) {
1176           GVs.push_back(GV);
1177           continue;
1178         }
1179         DISubprogram S(GV);
1180         if (S.isNull() == false) {
1181           SPs.push_back(GV);
1182           continue;
1183         }
1184       }
1185     }
1186   }
1187
1188   /// isValidDebugInfoIntrinsic - Return true if SPI is a valid debug
1189   /// info intrinsic.
1190   bool isValidDebugInfoIntrinsic(DbgStopPointInst &SPI,
1191                                  CodeGenOpt::Level OptLev) {
1192     return DIDescriptor::ValidDebugInfo(SPI.getContext(), OptLev);
1193   }
1194
1195   /// isValidDebugInfoIntrinsic - Return true if FSI is a valid debug
1196   /// info intrinsic.
1197   bool isValidDebugInfoIntrinsic(DbgFuncStartInst &FSI,
1198                                  CodeGenOpt::Level OptLev) {
1199     return DIDescriptor::ValidDebugInfo(FSI.getSubprogram(), OptLev);
1200   }
1201
1202   /// isValidDebugInfoIntrinsic - Return true if RSI is a valid debug
1203   /// info intrinsic.
1204   bool isValidDebugInfoIntrinsic(DbgRegionStartInst &RSI,
1205                                  CodeGenOpt::Level OptLev) {
1206     return DIDescriptor::ValidDebugInfo(RSI.getContext(), OptLev);
1207   }
1208
1209   /// isValidDebugInfoIntrinsic - Return true if REI is a valid debug
1210   /// info intrinsic.
1211   bool isValidDebugInfoIntrinsic(DbgRegionEndInst &REI,
1212                                  CodeGenOpt::Level OptLev) {
1213     return DIDescriptor::ValidDebugInfo(REI.getContext(), OptLev);
1214   }
1215
1216
1217   /// isValidDebugInfoIntrinsic - Return true if DI is a valid debug
1218   /// info intrinsic.
1219   bool isValidDebugInfoIntrinsic(DbgDeclareInst &DI,
1220                                  CodeGenOpt::Level OptLev) {
1221     return DIDescriptor::ValidDebugInfo(DI.getVariable(), OptLev);
1222   }
1223
1224   /// ExtractDebugLocation - Extract debug location information
1225   /// from llvm.dbg.stoppoint intrinsic.
1226   DebugLoc ExtractDebugLocation(DbgStopPointInst &SPI,
1227                                 DebugLocTracker &DebugLocInfo) {
1228     DebugLoc DL;
1229     Value *Context = SPI.getContext();
1230
1231     // If this location is already tracked then use it.
1232     DebugLocTuple Tuple(cast<GlobalVariable>(Context), SPI.getLine(),
1233                         SPI.getColumn());
1234     DenseMap<DebugLocTuple, unsigned>::iterator II
1235       = DebugLocInfo.DebugIdMap.find(Tuple);
1236     if (II != DebugLocInfo.DebugIdMap.end())
1237       return DebugLoc::get(II->second);
1238
1239     // Add a new location entry.
1240     unsigned Id = DebugLocInfo.DebugLocations.size();
1241     DebugLocInfo.DebugLocations.push_back(Tuple);
1242     DebugLocInfo.DebugIdMap[Tuple] = Id;
1243
1244     return DebugLoc::get(Id);
1245   }
1246
1247   /// ExtractDebugLocation - Extract debug location information
1248   /// from llvm.dbg.func_start intrinsic.
1249   DebugLoc ExtractDebugLocation(DbgFuncStartInst &FSI,
1250                                 DebugLocTracker &DebugLocInfo) {
1251     DebugLoc DL;
1252     Value *SP = FSI.getSubprogram();
1253
1254     DISubprogram Subprogram(cast<GlobalVariable>(SP));
1255     unsigned Line = Subprogram.getLineNumber();
1256     DICompileUnit CU(Subprogram.getCompileUnit());
1257
1258     // If this location is already tracked then use it.
1259     DebugLocTuple Tuple(CU.getGV(), Line, /* Column */ 0);
1260     DenseMap<DebugLocTuple, unsigned>::iterator II
1261       = DebugLocInfo.DebugIdMap.find(Tuple);
1262     if (II != DebugLocInfo.DebugIdMap.end())
1263       return DebugLoc::get(II->second);
1264
1265     // Add a new location entry.
1266     unsigned Id = DebugLocInfo.DebugLocations.size();
1267     DebugLocInfo.DebugLocations.push_back(Tuple);
1268     DebugLocInfo.DebugIdMap[Tuple] = Id;
1269
1270     return DebugLoc::get(Id);
1271   }
1272
1273   /// isInlinedFnStart - Return true if FSI is starting an inlined function.
1274   bool isInlinedFnStart(DbgFuncStartInst &FSI, const Function *CurrentFn) {
1275     DISubprogram Subprogram(cast<GlobalVariable>(FSI.getSubprogram()));
1276     if (Subprogram.describes(CurrentFn))
1277       return false;
1278
1279     return true;
1280   }
1281
1282   /// isInlinedFnEnd - Return true if REI is ending an inlined function.
1283   bool isInlinedFnEnd(DbgRegionEndInst &REI, const Function *CurrentFn) {
1284     DISubprogram Subprogram(cast<GlobalVariable>(REI.getContext()));
1285     if (Subprogram.isNull() || Subprogram.describes(CurrentFn))
1286       return false;
1287
1288     return true;
1289   }
1290
1291 }