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/Module.h"
  22 #include "llvm/Analysis/ValueTracking.h"
  23 #include "llvm/Support/Dwarf.h"
  24 using namespace llvm;
  25
  26 //===----------------------------------------------------------------------===//
  27 // DIDescriptor
  28 //===----------------------------------------------------------------------===//
  29
  30 DIDescriptor::DIDescriptor(GlobalVariable *gv, unsigned RequiredTag) {
  31   GV = gv;
  32
  33   // If this is non-null, check to see if the Tag matches.  If not, set to null.
  34   if (GV && getTag() != RequiredTag)
  35     GV = 0;
  36 }
  37
  38
  39 std::string DIDescriptor::getStringField(unsigned Elt) const {
  40   if (GV == 0) return "";
  41   Constant *C = GV->getInitializer();
  42   if (C == 0 || Elt >= C->getNumOperands())
  43     return "";
  44
  45   std::string Result;
  46   // Fills in the string if it succeeds
  47   if (!GetConstantStringInfo(C->getOperand(Elt), Result))
  48     Result.clear();
  49   return Result;
  50 }
  51
  52 uint64_t DIDescriptor::getUInt64Field(unsigned Elt) const {
  53   if (GV == 0) return 0;
  54   Constant *C = GV->getInitializer();
  55   if (C == 0 || Elt >= C->getNumOperands())
  56     return 0;
  57   if (ConstantInt *CI = dyn_cast<ConstantInt>(C->getOperand(Elt)))
  58     return CI->getZExtValue();
  59   return 0;
  60 }
  61
  62
  63 DIDescriptor DIDescriptor::getDescriptorField(unsigned Elt) const {
  64   if (GV == 0) return DIDescriptor();
  65   Constant *C = GV->getInitializer();
  66   if (C == 0 || Elt >= C->getNumOperands())
  67     return DIDescriptor();
  68   C = C->getOperand(Elt);
  69   return DIDescriptor(dyn_cast<GlobalVariable>(C->stripPointerCasts()));
  70 }
  71
  72 GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
  73   if (GV == 0) return 0;
  74   Constant *C = GV->getInitializer();
  75   if (C == 0 || Elt >= C->getNumOperands())
  76     return 0;
  77   C = C->getOperand(Elt);
  78
  79   return dyn_cast<GlobalVariable>(C->stripPointerCasts());
  80 }
  81
  82
  83
  84 //===----------------------------------------------------------------------===//
  85 // Simple Descriptor Constructors and other Methods
  86 //===----------------------------------------------------------------------===//
  87
  88 DIAnchor::DIAnchor(GlobalVariable *GV)
  89   : DIDescriptor(GV, dwarf::DW_TAG_anchor) {}
  90 DIEnumerator::DIEnumerator(GlobalVariable *GV)
  91   : DIDescriptor(GV, dwarf::DW_TAG_enumerator) {}
  92 DISubrange::DISubrange(GlobalVariable *GV)
  93   : DIDescriptor(GV, dwarf::DW_TAG_subrange_type) {}
  94 DICompileUnit::DICompileUnit(GlobalVariable *GV)
  95   : DIDescriptor(GV, dwarf::DW_TAG_compile_unit) {}
  96 DIBasicType::DIBasicType(GlobalVariable *GV)
  97   : DIType(GV, dwarf::DW_TAG_base_type) {}
  98 DISubprogram::DISubprogram(GlobalVariable *GV)
  99   : DIGlobal(GV, dwarf::DW_TAG_subprogram) {}
 100 DIGlobalVariable::DIGlobalVariable(GlobalVariable *GV)
 101   : DIGlobal(GV, dwarf::DW_TAG_variable) {}
 102 DIBlock::DIBlock(GlobalVariable *GV)
 103   : DIDescriptor(GV, dwarf::DW_TAG_lexical_block) {}
 104 // needed by DIVariable::getType()
 105 DIType::DIType(GlobalVariable *gv) : DIDescriptor(gv) {
 106   if (!gv) return;
 107   unsigned tag = getTag();
 108   if (tag != dwarf::DW_TAG_base_type && !DIDerivedType::isDerivedType(tag) &&
 109       !DICompositeType::isCompositeType(tag))
 110     GV = 0;
 111 }
 112
 113 /// isDerivedType - Return true if the specified tag is legal for
 114 /// DIDerivedType.
 115 bool DIDerivedType::isDerivedType(unsigned Tag) {
 116   switch (Tag) {
 117   case dwarf::DW_TAG_typedef:
 118   case dwarf::DW_TAG_pointer_type:
 119   case dwarf::DW_TAG_reference_type:
 120   case dwarf::DW_TAG_const_type:
 121   case dwarf::DW_TAG_volatile_type:
 122   case dwarf::DW_TAG_restrict_type:
 123   case dwarf::DW_TAG_member:
 124   case dwarf::DW_TAG_inheritance:
 125     return true;
 126   default:
 127     // FIXME: Even though it doesn't make sense, CompositeTypes are current
 128     // modelled as DerivedTypes, this should return true for them as well.
 129     return false;
 130   }
 131 }
 132
 133 DIDerivedType::DIDerivedType(GlobalVariable *GV) : DIType(GV, true, true) {
 134   if (GV && !isDerivedType(getTag()))
 135     GV = 0;
 136 }
 137
 138 /// isCompositeType - Return true if the specified tag is legal for
 139 /// DICompositeType.
 140 bool DICompositeType::isCompositeType(unsigned TAG) {
 141   switch (TAG) {
 142   case dwarf::DW_TAG_array_type:
 143   case dwarf::DW_TAG_structure_type:
 144   case dwarf::DW_TAG_union_type:
 145   case dwarf::DW_TAG_enumeration_type:
 146   case dwarf::DW_TAG_vector_type:
 147   case dwarf::DW_TAG_subroutine_type:
 148     return true;
 149   default:
 150     return false;
 151   }
 152 }
 153
 154 DICompositeType::DICompositeType(GlobalVariable *GV)
 155   : DIDerivedType(GV, true, true) {
 156   if (GV && !isCompositeType(getTag()))
 157     GV = 0;
 158 }
 159
 160 /// isVariable - Return true if the specified tag is legal for DIVariable.
 161 bool DIVariable::isVariable(unsigned Tag) {
 162   switch (Tag) {
 163   case dwarf::DW_TAG_auto_variable:
 164   case dwarf::DW_TAG_arg_variable:
 165   case dwarf::DW_TAG_return_variable:
 166     return true;
 167   default:
 168     return false;
 169   }
 170 }
 171
 172 DIVariable::DIVariable(GlobalVariable *GV) : DIDescriptor(GV) {
 173   if (GV && !isVariable(getTag()))
 174     GV = 0;
 175 }
 176
 177
 178
 179 //===----------------------------------------------------------------------===//
 180 // DIFactory: Basic Helpers
 181 //===----------------------------------------------------------------------===//
 182
 183 DIFactory::DIFactory(Module &m) : M(m) {
 184   StopPointFn = FuncStartFn = RegionStartFn = RegionEndFn = DeclareFn = 0;
 185   EmptyStructPtr = PointerType::getUnqual(StructType::get(NULL, NULL));
 186 }
 187
 188 /// getCastToEmpty - Return this descriptor as a Constant* with type '{}*'.
 189 /// This is only valid when the descriptor is non-null.
 190 Constant *DIFactory::getCastToEmpty(DIDescriptor D) {
 191   if (D.isNull()) return Constant::getNullValue(EmptyStructPtr);
 192   return ConstantExpr::getBitCast(D.getGV(), EmptyStructPtr);
 193 }
 194
 195 Constant *DIFactory::GetTagConstant(unsigned TAG) {
 196   assert((TAG & DIDescriptor::VersionMask) == 0 &&
 197          "Tag too large for debug encoding!");
 198   return ConstantInt::get(Type::Int32Ty, TAG | DIDescriptor::Version6);
 199 }
 200
 201 Constant *DIFactory::GetStringConstant(const std::string &String) {
 202   // Check string cache for previous edition.
 203   Constant *&Slot = StringCache[String];
 204
 205   // Return Constant if previously defined.
 206   if (Slot) return Slot;
 207
 208   const PointerType *DestTy = PointerType::getUnqual(Type::Int8Ty);
 209
 210   // If empty string then use a sbyte* null instead.
 211   if (String.empty())
 212     return Slot = ConstantPointerNull::get(DestTy);
 213
 214   // Construct string as an llvm constant.
 215   Constant *ConstStr = ConstantArray::get(String);
 216
 217   // Otherwise create and return a new string global.
 218   GlobalVariable *StrGV = new GlobalVariable(ConstStr->getType(), true,
 219                                              GlobalVariable::InternalLinkage,
 220                                              ConstStr, ".str", &M);
 221   StrGV->setSection("llvm.metadata");
 222   return Slot = ConstantExpr::getBitCast(StrGV, DestTy);
 223 }
 224
 225 /// GetOrCreateAnchor - Look up an anchor for the specified tag and name.  If it
 226 /// already exists, return it.  If not, create a new one and return it.
 227 DIAnchor DIFactory::GetOrCreateAnchor(unsigned TAG, const char *Name) {
 228   const Type *EltTy = StructType::get(Type::Int32Ty, Type::Int32Ty, NULL);
 229
 230   // Otherwise, create the global or return it if already in the module.
 231   Constant *C = M.getOrInsertGlobal(Name, EltTy);
 232   assert(isa<GlobalVariable>(C) && "Incorrectly typed anchor?");
 233   GlobalVariable *GV = cast<GlobalVariable>(C);
 234
 235   // If it has an initializer, it is already in the module.
 236   if (GV->hasInitializer())
 237     return SubProgramAnchor = DIAnchor(GV);
 238
 239   GV->setLinkage(GlobalValue::LinkOnceLinkage);
 240   GV->setSection("llvm.metadata");
 241   GV->setConstant(true);
 242   M.addTypeName("llvm.dbg.anchor.type", EltTy);
 243
 244   // Otherwise, set the initializer.
 245   Constant *Elts[] = {
 246     GetTagConstant(dwarf::DW_TAG_anchor),
 247     ConstantInt::get(Type::Int32Ty, TAG)
 248   };
 249
 250   GV->setInitializer(ConstantStruct::get(Elts, 2));
 251   return DIAnchor(GV);
 252 }
 253
 254
 255
 256 //===----------------------------------------------------------------------===//
 257 // DIFactory: Primary Constructors
 258 //===----------------------------------------------------------------------===//
 259
 260 /// GetOrCreateCompileUnitAnchor - Return the anchor for compile units,
 261 /// creating a new one if there isn't already one in the module.
 262 DIAnchor DIFactory::GetOrCreateCompileUnitAnchor() {
 263   // If we already created one, just return it.
 264   if (!CompileUnitAnchor.isNull())
 265     return CompileUnitAnchor;
 266   return CompileUnitAnchor = GetOrCreateAnchor(dwarf::DW_TAG_compile_unit,
 267                                                "llvm.dbg.compile_units");
 268 }
 269
 270 /// GetOrCreateSubprogramAnchor - Return the anchor for subprograms,
 271 /// creating a new one if there isn't already one in the module.
 272 DIAnchor DIFactory::GetOrCreateSubprogramAnchor() {
 273   // If we already created one, just return it.
 274   if (!SubProgramAnchor.isNull())
 275     return SubProgramAnchor;
 276   return SubProgramAnchor = GetOrCreateAnchor(dwarf::DW_TAG_subprogram,
 277                                               "llvm.dbg.subprograms");
 278 }
 279
 280 /// GetOrCreateGlobalVariableAnchor - Return the anchor for globals,
 281 /// creating a new one if there isn't already one in the module.
 282 DIAnchor DIFactory::GetOrCreateGlobalVariableAnchor() {
 283   // If we already created one, just return it.
 284   if (!GlobalVariableAnchor.isNull())
 285     return GlobalVariableAnchor;
 286   return GlobalVariableAnchor = GetOrCreateAnchor(dwarf::DW_TAG_variable,
 287                                                   "llvm.dbg.global_variables");
 288 }
 289
 290 /// GetOrCreateArray - Create an descriptor for an array of descriptors.
 291 /// This implicitly uniques the arrays created.
 292 DIArray DIFactory::GetOrCreateArray(DIDescriptor *Tys, unsigned NumTys) {
 293   SmallVector<Constant*, 16> Elts;
 294
 295   for (unsigned i = 0; i != NumTys; ++i)
 296     Elts.push_back(getCastToEmpty(Tys[i]));
 297
 298   Constant *Init = ConstantArray::get(ArrayType::get(EmptyStructPtr,
 299                                                      Elts.size()),
 300                                       &Elts[0], Elts.size());
 301   // If we already have this array, just return the uniqued version.
 302   DIDescriptor &Entry = SimpleConstantCache[Init];
 303   if (!Entry.isNull()) return DIArray(Entry.getGV());
 304
 305   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 306                                           GlobalValue::InternalLinkage,
 307                                           Init, "llvm.dbg.array", &M);
 308   GV->setSection("llvm.metadata");
 309   Entry = DIDescriptor(GV);
 310   return DIArray(GV);
 311 }
 312
 313 /// GetOrCreateSubrange - Create a descriptor for a value range.  This
 314 /// implicitly uniques the values returned.
 315 DISubrange DIFactory::GetOrCreateSubrange(int64_t Lo, int64_t Hi) {
 316   Constant *Elts[] = {
 317     GetTagConstant(dwarf::DW_TAG_subrange_type),
 318     ConstantInt::get(Type::Int64Ty, Lo),
 319     ConstantInt::get(Type::Int64Ty, Hi)
 320   };
 321
 322   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 323
 324   // If we already have this range, just return the uniqued version.
 325   DIDescriptor &Entry = SimpleConstantCache[Init];
 326   if (!Entry.isNull()) return DISubrange(Entry.getGV());
 327
 328   M.addTypeName("llvm.dbg.subrange.type", Init->getType());
 329
 330   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 331                                           GlobalValue::InternalLinkage,
 332                                           Init, "llvm.dbg.subrange", &M);
 333   GV->setSection("llvm.metadata");
 334   Entry = DIDescriptor(GV);
 335   return DISubrange(GV);
 336 }
 337
 338
 339
 340 /// CreateCompileUnit - Create a new descriptor for the specified compile
 341 /// unit.  Note that this does not unique compile units within the module.
 342 DICompileUnit DIFactory::CreateCompileUnit(unsigned LangID,
 343                                            const std::string &Filename,
 344                                            const std::string &Directory,
 345                                            const std::string &Producer) {
 346   Constant *Elts[] = {
 347     GetTagConstant(dwarf::DW_TAG_compile_unit),
 348     getCastToEmpty(GetOrCreateCompileUnitAnchor()),
 349     ConstantInt::get(Type::Int32Ty, LangID),
 350     GetStringConstant(Filename),
 351     GetStringConstant(Directory),
 352     GetStringConstant(Producer)
 353   };
 354
 355   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 356
 357   M.addTypeName("llvm.dbg.compile_unit.type", Init->getType());
 358   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 359                                           GlobalValue::InternalLinkage,
 360                                           Init, "llvm.dbg.compile_unit", &M);
 361   GV->setSection("llvm.metadata");
 362   return DICompileUnit(GV);
 363 }
 364
 365 /// CreateEnumerator - Create a single enumerator value.
 366 DIEnumerator DIFactory::CreateEnumerator(const std::string &Name, uint64_t Val){
 367   Constant *Elts[] = {
 368     GetTagConstant(dwarf::DW_TAG_enumerator),
 369     GetStringConstant(Name),
 370     ConstantInt::get(Type::Int64Ty, Val)
 371   };
 372
 373   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 374
 375   M.addTypeName("llvm.dbg.enumerator.type", Init->getType());
 376   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 377                                           GlobalValue::InternalLinkage,
 378                                           Init, "llvm.dbg.enumerator", &M);
 379   GV->setSection("llvm.metadata");
 380   return DIEnumerator(GV);
 381 }
 382
 383
 384 /// CreateBasicType - Create a basic type like int, float, etc.
 385 DIBasicType DIFactory::CreateBasicType(DIDescriptor Context,
 386                                       const std::string &Name,
 387                                        DICompileUnit CompileUnit,
 388                                        unsigned LineNumber,
 389                                        uint64_t SizeInBits,
 390                                        uint64_t AlignInBits,
 391                                        uint64_t OffsetInBits, unsigned Flags,
 392                                        unsigned Encoding) {
 393   Constant *Elts[] = {
 394     GetTagConstant(dwarf::DW_TAG_base_type),
 395     getCastToEmpty(Context),
 396     GetStringConstant(Name),
 397     getCastToEmpty(CompileUnit),
 398     ConstantInt::get(Type::Int32Ty, LineNumber),
 399     ConstantInt::get(Type::Int64Ty, SizeInBits),
 400     ConstantInt::get(Type::Int64Ty, AlignInBits),
 401     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 402     ConstantInt::get(Type::Int32Ty, Flags),
 403     ConstantInt::get(Type::Int32Ty, Encoding)
 404   };
 405
 406   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 407
 408   M.addTypeName("llvm.dbg.basictype.type", Init->getType());
 409   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 410                                           GlobalValue::InternalLinkage,
 411                                           Init, "llvm.dbg.basictype", &M);
 412   GV->setSection("llvm.metadata");
 413   return DIBasicType(GV);
 414 }
 415
 416 /// CreateDerivedType - Create a derived type like const qualified type,
 417 /// pointer, typedef, etc.
 418 DIDerivedType DIFactory::CreateDerivedType(unsigned Tag,
 419                                            DIDescriptor Context,
 420                                            const std::string &Name,
 421                                            DICompileUnit CompileUnit,
 422                                            unsigned LineNumber,
 423                                            uint64_t SizeInBits,
 424                                            uint64_t AlignInBits,
 425                                            uint64_t OffsetInBits,
 426                                            unsigned Flags,
 427                                            DIType DerivedFrom) {
 428   Constant *Elts[] = {
 429     GetTagConstant(Tag),
 430     getCastToEmpty(Context),
 431     GetStringConstant(Name),
 432     getCastToEmpty(CompileUnit),
 433     ConstantInt::get(Type::Int32Ty, LineNumber),
 434     ConstantInt::get(Type::Int64Ty, SizeInBits),
 435     ConstantInt::get(Type::Int64Ty, AlignInBits),
 436     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 437     ConstantInt::get(Type::Int32Ty, Flags),
 438     getCastToEmpty(DerivedFrom)
 439   };
 440
 441   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 442
 443   M.addTypeName("llvm.dbg.derivedtype.type", Init->getType());
 444   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 445                                           GlobalValue::InternalLinkage,
 446                                           Init, "llvm.dbg.derivedtype", &M);
 447   GV->setSection("llvm.metadata");
 448   return DIDerivedType(GV);
 449 }
 450
 451 /// CreateCompositeType - Create a composite type like array, struct, etc.
 452 DICompositeType DIFactory::CreateCompositeType(unsigned Tag,
 453                                                DIDescriptor Context,
 454                                                const std::string &Name,
 455                                                DICompileUnit CompileUnit,
 456                                                unsigned LineNumber,
 457                                                uint64_t SizeInBits,
 458                                                uint64_t AlignInBits,
 459                                                uint64_t OffsetInBits,
 460                                                unsigned Flags,
 461                                                DIType DerivedFrom,
 462                                                DIArray Elements) {
 463   Constant *Elts[] = {
 464     GetTagConstant(Tag),
 465     getCastToEmpty(Context),
 466     GetStringConstant(Name),
 467     getCastToEmpty(CompileUnit),
 468     ConstantInt::get(Type::Int32Ty, LineNumber),
 469     ConstantInt::get(Type::Int64Ty, SizeInBits),
 470     ConstantInt::get(Type::Int64Ty, AlignInBits),
 471     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 472     ConstantInt::get(Type::Int32Ty, Flags),
 473     getCastToEmpty(DerivedFrom),
 474     getCastToEmpty(Elements)
 475   };
 476
 477   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 478
 479   M.addTypeName("llvm.dbg.composite.type", Init->getType());
 480   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 481                                           GlobalValue::InternalLinkage,
 482                                           Init, "llvm.dbg.composite", &M);
 483   GV->setSection("llvm.metadata");
 484   return DICompositeType(GV);
 485 }
 486
 487
 488 /// CreateSubprogram - Create a new descriptor for the specified subprogram.
 489 /// See comments in DISubprogram for descriptions of these fields.  This
 490 /// method does not unique the generated descriptors.
 491 DISubprogram DIFactory::CreateSubprogram(DIDescriptor Context,
 492                                          const std::string &Name,
 493                                          const std::string &DisplayName,
 494                                          const std::string &LinkageName,
 495                                          DICompileUnit CompileUnit,
 496                                          unsigned LineNo, DIType Type,
 497                                          bool isLocalToUnit,
 498                                          bool isDefinition) {
 499   Constant *Elts[] = {
 500     GetTagConstant(dwarf::DW_TAG_subprogram),
 501     getCastToEmpty(GetOrCreateSubprogramAnchor()),
 502     getCastToEmpty(Context),
 503     GetStringConstant(Name),
 504     GetStringConstant(DisplayName),
 505     GetStringConstant(LinkageName),
 506     getCastToEmpty(CompileUnit),
 507     ConstantInt::get(Type::Int32Ty, LineNo),
 508     getCastToEmpty(Type),
 509     ConstantInt::get(Type::Int1Ty, isLocalToUnit),
 510     ConstantInt::get(Type::Int1Ty, isDefinition)
 511   };
 512
 513   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 514
 515   M.addTypeName("llvm.dbg.subprogram.type", Init->getType());
 516   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 517                                           GlobalValue::InternalLinkage,
 518                                           Init, "llvm.dbg.subprogram", &M);
 519   GV->setSection("llvm.metadata");
 520   return DISubprogram(GV);
 521 }
 522
 523 /// CreateGlobalVariable - Create a new descriptor for the specified global.
 524 DIGlobalVariable
 525 DIFactory::CreateGlobalVariable(DIDescriptor Context, const std::string &Name,
 526                                 const std::string &DisplayName,
 527                                 const std::string &LinkageName,
 528                                 DICompileUnit CompileUnit,
 529                                 unsigned LineNo, DIType Type,bool isLocalToUnit,
 530                                 bool isDefinition, llvm::GlobalVariable *Val) {
 531
 532   Constant *Elts[] = {
 533     GetTagConstant(dwarf::DW_TAG_variable),
 534     getCastToEmpty(GetOrCreateGlobalVariableAnchor()),
 535     getCastToEmpty(Context),
 536     GetStringConstant(Name),
 537     GetStringConstant(DisplayName),
 538     GetStringConstant(LinkageName),
 539     getCastToEmpty(CompileUnit),
 540     ConstantInt::get(Type::Int32Ty, LineNo),
 541     getCastToEmpty(Type),
 542     ConstantInt::get(Type::Int1Ty, isLocalToUnit),
 543     ConstantInt::get(Type::Int1Ty, isDefinition),
 544     ConstantExpr::getBitCast(Val, EmptyStructPtr)
 545   };
 546
 547   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 548
 549   M.addTypeName("llvm.dbg.global_variable.type", Init->getType());
 550   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 551                                           GlobalValue::InternalLinkage,
 552                                           Init, "llvm.dbg.global_variable", &M);
 553   GV->setSection("llvm.metadata");
 554   return DIGlobalVariable(GV);
 555 }
 556
 557
 558 /// CreateVariable - Create a new descriptor for the specified variable.
 559 DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
 560                                      const std::string &Name,
 561                                      DICompileUnit CompileUnit, unsigned LineNo,
 562                                      DIType Type) {
 563
 564   Constant *Elts[] = {
 565     GetTagConstant(Tag),
 566     getCastToEmpty(Context),
 567     GetStringConstant(Name),
 568     getCastToEmpty(CompileUnit),
 569     ConstantInt::get(Type::Int32Ty, LineNo),
 570     getCastToEmpty(Type),
 571   };
 572
 573   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 574
 575   M.addTypeName("llvm.dbg.variable.type", Init->getType());
 576   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 577                                           GlobalValue::InternalLinkage,
 578                                           Init, "llvm.dbg.variable", &M);
 579   GV->setSection("llvm.metadata");
 580   return DIVariable(GV);
 581 }
 582
 583
 584 /// CreateBlock - This creates a descriptor for a lexical block with the
 585 /// specified parent context.
 586 DIBlock DIFactory::CreateBlock(DIDescriptor Context) {
 587   Constant *Elts[] = {
 588     GetTagConstant(dwarf::DW_TAG_lexical_block),
 589     getCastToEmpty(Context)
 590   };
 591
 592   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 593
 594   M.addTypeName("llvm.dbg.block.type", Init->getType());
 595   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 596                                           GlobalValue::InternalLinkage,
 597                                           Init, "llvm.dbg.block", &M);
 598   GV->setSection("llvm.metadata");
 599   return DIBlock(GV);
 600 }
 601
 602
 603 //===----------------------------------------------------------------------===//
 604 // DIFactory: Routines for inserting code into a function
 605 //===----------------------------------------------------------------------===//
 606
 607 /// InsertStopPoint - Create a new llvm.dbg.stoppoint intrinsic invocation,
 608 /// inserting it at the end of the specified basic block.
 609 void DIFactory::InsertStopPoint(DICompileUnit CU, unsigned LineNo,
 610                                 unsigned ColNo, BasicBlock *BB) {
 611
 612   // Lazily construct llvm.dbg.stoppoint function.
 613   if (!StopPointFn)
 614     StopPointFn = llvm::Intrinsic::getDeclaration(&M,
 615                                               llvm::Intrinsic::dbg_stoppoint);
 616
 617   // Invoke llvm.dbg.stoppoint
 618   Value *Args[] = {
 619     llvm::ConstantInt::get(llvm::Type::Int32Ty, LineNo),
 620     llvm::ConstantInt::get(llvm::Type::Int32Ty, ColNo),
 621     getCastToEmpty(CU)
 622   };
 623   CallInst::Create(StopPointFn, Args, Args+3, "", BB);
 624 }
 625
 626 /// InsertSubprogramStart - Create a new llvm.dbg.func.start intrinsic to
 627 /// mark the start of the specified subprogram.
 628 void DIFactory::InsertSubprogramStart(DISubprogram SP, BasicBlock *BB) {
 629   // Lazily construct llvm.dbg.func.start.
 630   if (!FuncStartFn)
 631     FuncStartFn = llvm::Intrinsic::getDeclaration(&M,
 632                                               llvm::Intrinsic::dbg_func_start);
 633
 634   // Call llvm.dbg.func.start which also implicitly sets a stoppoint.
 635   CallInst::Create(FuncStartFn, getCastToEmpty(SP), "", BB);
 636 }
 637
 638 /// InsertRegionStart - Insert a new llvm.dbg.region.start intrinsic call to
 639 /// mark the start of a region for the specified scoping descriptor.
 640 void DIFactory::InsertRegionStart(DIDescriptor D, BasicBlock *BB) {
 641   // Lazily construct llvm.dbg.region.start function.
 642   if (!RegionStartFn)
 643     RegionStartFn = llvm::Intrinsic::getDeclaration(&M,
 644                                             llvm::Intrinsic::dbg_region_start);
 645   // Call llvm.dbg.func.start.
 646   CallInst::Create(RegionStartFn, getCastToEmpty(D), "", BB);
 647 }
 648
 649
 650 /// InsertRegionEnd - Insert a new llvm.dbg.region.end intrinsic call to
 651 /// mark the end of a region for the specified scoping descriptor.
 652 void DIFactory::InsertRegionEnd(DIDescriptor D, BasicBlock *BB) {
 653   // Lazily construct llvm.dbg.region.end function.
 654   if (!RegionEndFn)
 655     RegionEndFn = llvm::Intrinsic::getDeclaration(&M,
 656                                                llvm::Intrinsic::dbg_region_end);
 657
 658   CallInst::Create(RegionEndFn, getCastToEmpty(D), "", BB);
 659 }
 660
 661 /// InsertDeclare - Insert a new llvm.dbg.declare intrinsic call.
 662 void DIFactory::InsertDeclare(llvm::Value *Storage, DIVariable D,
 663                               BasicBlock *BB) {
 664   // Cast the storage to a {}* for the call to llvm.dbg.declare.
 665   Storage = new llvm::BitCastInst(Storage, EmptyStructPtr, "", BB);
 666
 667   if (!DeclareFn)
 668     DeclareFn = llvm::Intrinsic::getDeclaration(&M,
 669                                                 llvm::Intrinsic::dbg_declare);
 670   Value *Args[] = { Storage, getCastToEmpty(D) };
 671   CallInst::Create(DeclareFn, Args, Args+2, "", BB);
 672 }
 673
 674 namespace llvm {
 675   /// Finds the stoppoint coressponding to this instruction, that is the
 676   /// stoppoint that dominates this instruction
 677   const DbgStopPointInst *findStopPoint(const Instruction *Inst)
 678   {
 679     if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(Inst))
 680       return DSI;
 681
 682     const BasicBlock *BB = Inst->getParent();
 683     BasicBlock::const_iterator I = Inst, B;
 684     do {
 685       B = BB->begin();
 686       // A BB consisting only of a terminator can't have a stoppoint.
 687       if (I != B) {
 688         do {
 689           --I;
 690           if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(I))
 691             return DSI;
 692         } while (I != B);
 693       }
 694       // This BB didn't have a stoppoint: if there is only one
 695       // predecessor, look for a stoppoint there.
 696       // We could use getIDom(), but that would require dominator info.
 697       BB = I->getParent()->getUniquePredecessor();
 698       if (BB)
 699         I = BB->getTerminator();
 700     } while (BB != 0);
 701     return 0;
 702   }
 703
 704   /// Finds the stoppoint corresponding to first real (non-debug intrinsic)
 705   /// instruction in this Basic Block, and returns the stoppoint for it.
 706   const DbgStopPointInst *findBBStopPoint(const BasicBlock *BB)
 707   {
 708     for(BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
 709       if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(I))
 710         return DSI;
 711     }
 712     // Fallback to looking for stoppoint of unique predecessor.
 713     // Useful if this BB contains no stoppoints, but unique predecessor does.
 714     BB = BB->getUniquePredecessor();
 715     if (BB)
 716       return findStopPoint(BB->getTerminator());
 717     return 0;
 718   }
 719
 720   /// Finds the dbg.declare intrinsic corresponding to this value if any.
 721   /// It looks through pointer casts too.
 722   const DbgDeclareInst *findDbgDeclare(const Value *V, bool stripCasts)
 723   {
 724     if (stripCasts) {
 725       V = V->stripPointerCasts();
 726       // Look for the bitcast.
 727       for (Value::use_const_iterator I = V->use_begin(), E =V->use_end();
 728             I != E; ++I) {
 729         if (isa<BitCastInst>(I))
 730           return findDbgDeclare(*I, false);
 731       }
 732       return 0;
 733     }
 734
 735     // Find dbg.declare among uses of the instruction.
 736     for (Value::use_const_iterator I = V->use_begin(), E =V->use_end();
 737           I != E; ++I) {
 738       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I))
 739         return DDI;
 740     }
 741     return 0;
 742   }
 743 }
 744