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::Version7);
 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                                        const std::string *FileName,
 394                                        const std::string *Directory) {
 395   Constant *Elts[] = {
 396     GetTagConstant(dwarf::DW_TAG_base_type),
 397     getCastToEmpty(Context),
 398     GetStringConstant(Name),
 399     getCastToEmpty(CompileUnit),
 400     ConstantInt::get(Type::Int32Ty, LineNumber),
 401     ConstantInt::get(Type::Int64Ty, SizeInBits),
 402     ConstantInt::get(Type::Int64Ty, AlignInBits),
 403     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 404     ConstantInt::get(Type::Int32Ty, Flags),
 405     ConstantInt::get(Type::Int32Ty, Encoding),
 406     GetStringConstant(FileName ? FileName->c_str() : ""),
 407     GetStringConstant(Directory ? Directory->c_str() : "")
 408   };
 409
 410   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 411
 412   M.addTypeName("llvm.dbg.basictype.type", Init->getType());
 413   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 414                                           GlobalValue::InternalLinkage,
 415                                           Init, "llvm.dbg.basictype", &M);
 416   GV->setSection("llvm.metadata");
 417   return DIBasicType(GV);
 418 }
 419
 420 /// CreateDerivedType - Create a derived type like const qualified type,
 421 /// pointer, typedef, etc.
 422 DIDerivedType DIFactory::CreateDerivedType(unsigned Tag,
 423                                            DIDescriptor Context,
 424                                            const std::string &Name,
 425                                            DICompileUnit CompileUnit,
 426                                            unsigned LineNumber,
 427                                            uint64_t SizeInBits,
 428                                            uint64_t AlignInBits,
 429                                            uint64_t OffsetInBits,
 430                                            unsigned Flags,
 431                                            DIType DerivedFrom,
 432                                            const std::string *FileName,
 433                                            const std::string *Directory) {
 434   Constant *Elts[] = {
 435     GetTagConstant(Tag),
 436     getCastToEmpty(Context),
 437     GetStringConstant(Name),
 438     getCastToEmpty(CompileUnit),
 439     ConstantInt::get(Type::Int32Ty, LineNumber),
 440     ConstantInt::get(Type::Int64Ty, SizeInBits),
 441     ConstantInt::get(Type::Int64Ty, AlignInBits),
 442     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 443     ConstantInt::get(Type::Int32Ty, Flags),
 444     getCastToEmpty(DerivedFrom),
 445     GetStringConstant(FileName ? FileName->c_str() : ""),
 446     GetStringConstant(Directory ? Directory->c_str() : "")
 447   };
 448
 449   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 450
 451   M.addTypeName("llvm.dbg.derivedtype.type", Init->getType());
 452   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 453                                           GlobalValue::InternalLinkage,
 454                                           Init, "llvm.dbg.derivedtype", &M);
 455   GV->setSection("llvm.metadata");
 456   return DIDerivedType(GV);
 457 }
 458
 459 /// CreateCompositeType - Create a composite type like array, struct, etc.
 460 DICompositeType DIFactory::CreateCompositeType(unsigned Tag,
 461                                                DIDescriptor Context,
 462                                                const std::string &Name,
 463                                                DICompileUnit CompileUnit,
 464                                                unsigned LineNumber,
 465                                                uint64_t SizeInBits,
 466                                                uint64_t AlignInBits,
 467                                                uint64_t OffsetInBits,
 468                                                unsigned Flags,
 469                                                DIType DerivedFrom,
 470                                                DIArray Elements,
 471                                                const std::string *FileName,
 472                                                const std::string *Directory) {
 473
 474   Constant *Elts[] = {
 475     GetTagConstant(Tag),
 476     getCastToEmpty(Context),
 477     GetStringConstant(Name),
 478     getCastToEmpty(CompileUnit),
 479     ConstantInt::get(Type::Int32Ty, LineNumber),
 480     ConstantInt::get(Type::Int64Ty, SizeInBits),
 481     ConstantInt::get(Type::Int64Ty, AlignInBits),
 482     ConstantInt::get(Type::Int64Ty, OffsetInBits),
 483     ConstantInt::get(Type::Int32Ty, Flags),
 484     getCastToEmpty(DerivedFrom),
 485     getCastToEmpty(Elements),
 486     GetStringConstant(FileName ? FileName->c_str() : ""),
 487     GetStringConstant(Directory ? Directory->c_str() : "")
 488   };
 489
 490   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 491
 492   M.addTypeName("llvm.dbg.composite.type", Init->getType());
 493   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 494                                           GlobalValue::InternalLinkage,
 495                                           Init, "llvm.dbg.composite", &M);
 496   GV->setSection("llvm.metadata");
 497   return DICompositeType(GV);
 498 }
 499
 500
 501 /// CreateSubprogram - Create a new descriptor for the specified subprogram.
 502 /// See comments in DISubprogram for descriptions of these fields.  This
 503 /// method does not unique the generated descriptors.
 504 DISubprogram DIFactory::CreateSubprogram(DIDescriptor Context,
 505                                          const std::string &Name,
 506                                          const std::string &DisplayName,
 507                                          const std::string &LinkageName,
 508                                          DICompileUnit CompileUnit,
 509                                          unsigned LineNo, DIType Type,
 510                                          bool isLocalToUnit,
 511                                          bool isDefinition,
 512                                          const std::string *FileName,
 513                                          const std::string *Directory) {
 514
 515   Constant *Elts[] = {
 516     GetTagConstant(dwarf::DW_TAG_subprogram),
 517     getCastToEmpty(GetOrCreateSubprogramAnchor()),
 518     getCastToEmpty(Context),
 519     GetStringConstant(Name),
 520     GetStringConstant(DisplayName),
 521     GetStringConstant(LinkageName),
 522     getCastToEmpty(CompileUnit),
 523     ConstantInt::get(Type::Int32Ty, LineNo),
 524     getCastToEmpty(Type),
 525     ConstantInt::get(Type::Int1Ty, isLocalToUnit),
 526     ConstantInt::get(Type::Int1Ty, isDefinition),
 527     GetStringConstant(FileName ? FileName->c_str() : ""),
 528     GetStringConstant(Directory ? Directory->c_str() : "")
 529   };
 530
 531   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 532
 533   M.addTypeName("llvm.dbg.subprogram.type", Init->getType());
 534   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 535                                           GlobalValue::InternalLinkage,
 536                                           Init, "llvm.dbg.subprogram", &M);
 537   GV->setSection("llvm.metadata");
 538   return DISubprogram(GV);
 539 }
 540
 541 /// CreateGlobalVariable - Create a new descriptor for the specified global.
 542 DIGlobalVariable
 543 DIFactory::CreateGlobalVariable(DIDescriptor Context, const std::string &Name,
 544                                 const std::string &DisplayName,
 545                                 const std::string &LinkageName,
 546                                 DICompileUnit CompileUnit,
 547                                 unsigned LineNo, DIType Type,bool isLocalToUnit,
 548                                 bool isDefinition, llvm::GlobalVariable *Val,
 549                                 const std::string *FileName,
 550                                 const std::string *Directory) {
 551   Constant *Elts[] = {
 552     GetTagConstant(dwarf::DW_TAG_variable),
 553     getCastToEmpty(GetOrCreateGlobalVariableAnchor()),
 554     getCastToEmpty(Context),
 555     GetStringConstant(Name),
 556     GetStringConstant(DisplayName),
 557     GetStringConstant(LinkageName),
 558     getCastToEmpty(CompileUnit),
 559     ConstantInt::get(Type::Int32Ty, LineNo),
 560     getCastToEmpty(Type),
 561     ConstantInt::get(Type::Int1Ty, isLocalToUnit),
 562     ConstantInt::get(Type::Int1Ty, isDefinition),
 563     ConstantExpr::getBitCast(Val, EmptyStructPtr),
 564     GetStringConstant(FileName ? FileName->c_str() : ""),
 565     GetStringConstant(Directory ? Directory->c_str() : "")
 566   };
 567
 568   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 569
 570   M.addTypeName("llvm.dbg.global_variable.type", Init->getType());
 571   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 572                                           GlobalValue::InternalLinkage,
 573                                           Init, "llvm.dbg.global_variable", &M);
 574   GV->setSection("llvm.metadata");
 575   return DIGlobalVariable(GV);
 576 }
 577
 578
 579 /// CreateVariable - Create a new descriptor for the specified variable.
 580 DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
 581                                      const std::string &Name,
 582                                      DICompileUnit CompileUnit, unsigned LineNo,
 583                                      DIType Type,
 584                                      const std::string *FileName,
 585                                      const std::string *Directory) {
 586
 587
 588   Constant *Elts[] = {
 589     GetTagConstant(Tag),
 590     getCastToEmpty(Context),
 591     GetStringConstant(Name),
 592     getCastToEmpty(CompileUnit),
 593     ConstantInt::get(Type::Int32Ty, LineNo),
 594     getCastToEmpty(Type),
 595     GetStringConstant(FileName ? FileName->c_str() : ""),
 596     GetStringConstant(Directory ? Directory->c_str() : "")
 597   };
 598
 599   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 600
 601   M.addTypeName("llvm.dbg.variable.type", Init->getType());
 602   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 603                                           GlobalValue::InternalLinkage,
 604                                           Init, "llvm.dbg.variable", &M);
 605   GV->setSection("llvm.metadata");
 606   return DIVariable(GV);
 607 }
 608
 609
 610 /// CreateBlock - This creates a descriptor for a lexical block with the
 611 /// specified parent context.
 612 DIBlock DIFactory::CreateBlock(DIDescriptor Context) {
 613   Constant *Elts[] = {
 614     GetTagConstant(dwarf::DW_TAG_lexical_block),
 615     getCastToEmpty(Context)
 616   };
 617
 618   Constant *Init = ConstantStruct::get(Elts, sizeof(Elts)/sizeof(Elts[0]));
 619
 620   M.addTypeName("llvm.dbg.block.type", Init->getType());
 621   GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
 622                                           GlobalValue::InternalLinkage,
 623                                           Init, "llvm.dbg.block", &M);
 624   GV->setSection("llvm.metadata");
 625   return DIBlock(GV);
 626 }
 627
 628
 629 //===----------------------------------------------------------------------===//
 630 // DIFactory: Routines for inserting code into a function
 631 //===----------------------------------------------------------------------===//
 632
 633 /// InsertStopPoint - Create a new llvm.dbg.stoppoint intrinsic invocation,
 634 /// inserting it at the end of the specified basic block.
 635 void DIFactory::InsertStopPoint(DICompileUnit CU, unsigned LineNo,
 636                                 unsigned ColNo, BasicBlock *BB) {
 637
 638   // Lazily construct llvm.dbg.stoppoint function.
 639   if (!StopPointFn)
 640     StopPointFn = llvm::Intrinsic::getDeclaration(&M,
 641                                               llvm::Intrinsic::dbg_stoppoint);
 642
 643   // Invoke llvm.dbg.stoppoint
 644   Value *Args[] = {
 645     llvm::ConstantInt::get(llvm::Type::Int32Ty, LineNo),
 646     llvm::ConstantInt::get(llvm::Type::Int32Ty, ColNo),
 647     getCastToEmpty(CU)
 648   };
 649   CallInst::Create(StopPointFn, Args, Args+3, "", BB);
 650 }
 651
 652 /// InsertSubprogramStart - Create a new llvm.dbg.func.start intrinsic to
 653 /// mark the start of the specified subprogram.
 654 void DIFactory::InsertSubprogramStart(DISubprogram SP, BasicBlock *BB) {
 655   // Lazily construct llvm.dbg.func.start.
 656   if (!FuncStartFn)
 657     FuncStartFn = llvm::Intrinsic::getDeclaration(&M,
 658                                               llvm::Intrinsic::dbg_func_start);
 659
 660   // Call llvm.dbg.func.start which also implicitly sets a stoppoint.
 661   CallInst::Create(FuncStartFn, getCastToEmpty(SP), "", BB);
 662 }
 663
 664 /// InsertRegionStart - Insert a new llvm.dbg.region.start intrinsic call to
 665 /// mark the start of a region for the specified scoping descriptor.
 666 void DIFactory::InsertRegionStart(DIDescriptor D, BasicBlock *BB) {
 667   // Lazily construct llvm.dbg.region.start function.
 668   if (!RegionStartFn)
 669     RegionStartFn = llvm::Intrinsic::getDeclaration(&M,
 670                                             llvm::Intrinsic::dbg_region_start);
 671   // Call llvm.dbg.func.start.
 672   CallInst::Create(RegionStartFn, getCastToEmpty(D), "", BB);
 673 }
 674
 675
 676 /// InsertRegionEnd - Insert a new llvm.dbg.region.end intrinsic call to
 677 /// mark the end of a region for the specified scoping descriptor.
 678 void DIFactory::InsertRegionEnd(DIDescriptor D, BasicBlock *BB) {
 679   // Lazily construct llvm.dbg.region.end function.
 680   if (!RegionEndFn)
 681     RegionEndFn = llvm::Intrinsic::getDeclaration(&M,
 682                                                llvm::Intrinsic::dbg_region_end);
 683
 684   CallInst::Create(RegionEndFn, getCastToEmpty(D), "", BB);
 685 }
 686
 687 /// InsertDeclare - Insert a new llvm.dbg.declare intrinsic call.
 688 void DIFactory::InsertDeclare(llvm::Value *Storage, DIVariable D,
 689                               BasicBlock *BB) {
 690   // Cast the storage to a {}* for the call to llvm.dbg.declare.
 691   Storage = new llvm::BitCastInst(Storage, EmptyStructPtr, "", BB);
 692
 693   if (!DeclareFn)
 694     DeclareFn = llvm::Intrinsic::getDeclaration(&M,
 695                                                 llvm::Intrinsic::dbg_declare);
 696   Value *Args[] = { Storage, getCastToEmpty(D) };
 697   CallInst::Create(DeclareFn, Args, Args+2, "", BB);
 698 }
 699
 700 namespace llvm {
 701   /// Finds the stoppoint coressponding to this instruction, that is the
 702   /// stoppoint that dominates this instruction
 703   const DbgStopPointInst *findStopPoint(const Instruction *Inst)
 704   {
 705     if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(Inst))
 706       return DSI;
 707
 708     const BasicBlock *BB = Inst->getParent();
 709     BasicBlock::const_iterator I = Inst, B;
 710     do {
 711       B = BB->begin();
 712       // A BB consisting only of a terminator can't have a stoppoint.
 713       if (I != B) {
 714         do {
 715           --I;
 716           if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(I))
 717             return DSI;
 718         } while (I != B);
 719       }
 720       // This BB didn't have a stoppoint: if there is only one
 721       // predecessor, look for a stoppoint there.
 722       // We could use getIDom(), but that would require dominator info.
 723       BB = I->getParent()->getUniquePredecessor();
 724       if (BB)
 725         I = BB->getTerminator();
 726     } while (BB != 0);
 727     return 0;
 728   }
 729
 730   /// Finds the stoppoint corresponding to first real (non-debug intrinsic)
 731   /// instruction in this Basic Block, and returns the stoppoint for it.
 732   const DbgStopPointInst *findBBStopPoint(const BasicBlock *BB)
 733   {
 734     for(BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
 735       if (const DbgStopPointInst *DSI = dyn_cast<DbgStopPointInst>(I))
 736         return DSI;
 737     }
 738     // Fallback to looking for stoppoint of unique predecessor.
 739     // Useful if this BB contains no stoppoints, but unique predecessor does.
 740     BB = BB->getUniquePredecessor();
 741     if (BB)
 742       return findStopPoint(BB->getTerminator());
 743     return 0;
 744   }
 745
 746   /// Finds the dbg.declare intrinsic corresponding to this value if any.
 747   /// It looks through pointer casts too.
 748   const DbgDeclareInst *findDbgDeclare(const Value *V, bool stripCasts)
 749   {
 750     if (stripCasts) {
 751       V = V->stripPointerCasts();
 752       // Look for the bitcast.
 753       for (Value::use_const_iterator I = V->use_begin(), E =V->use_end();
 754             I != E; ++I) {
 755         if (isa<BitCastInst>(I))
 756           return findDbgDeclare(*I, false);
 757       }
 758       return 0;
 759     }
 760
 761     // Find dbg.declare among uses of the instruction.
 762     for (Value::use_const_iterator I = V->use_begin(), E =V->use_end();
 763           I != E; ++I) {
 764       if (const DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I))
 765         return DDI;
 766     }
 767     return 0;
 768   }
 769 }
 770