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