CGDebugInfo.cpp revision 9bc093c9309e04ebfff4123790405241513da1b4 
1//===--- CGDebugInfo.cpp - Emit Debug Information for a Module ------------===//
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 coordinates the debug information generation while generating code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CGDebugInfo.h"
15#include "CodeGenModule.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/DeclObjC.h"
18#include "clang/AST/Expr.h"
19#include "clang/AST/RecordLayout.h"
20#include "clang/Basic/SourceManager.h"
21#include "clang/Basic/FileManager.h"
22#include "clang/Frontend/CompileOptions.h"
23#include "llvm/Constants.h"
24#include "llvm/DerivedTypes.h"
25#include "llvm/Instructions.h"
26#include "llvm/Intrinsics.h"
27#include "llvm/Module.h"
28#include "llvm/ADT/StringExtras.h"
29#include "llvm/ADT/SmallVector.h"
30#include "llvm/Support/Dwarf.h"
31#include "llvm/System/Path.h"
32#include "llvm/Target/TargetMachine.h"
33using namespace clang;
34using namespace clang::CodeGen;
35
36CGDebugInfo::CGDebugInfo(CodeGenModule *m)
37  : M(m), isMainCompileUnitCreated(false), DebugFactory(M->getModule()),
38    BlockLiteralGenericSet(false) {
39}
40
41CGDebugInfo::~CGDebugInfo() {
42  assert(RegionStack.empty() && "Region stack mismatch, stack not empty!");
43}
44
45void CGDebugInfo::setLocation(SourceLocation Loc) {
46  if (Loc.isValid())
47    CurLoc = M->getContext().getSourceManager().getInstantiationLoc(Loc);
48}
49
50/// getOrCreateCompileUnit - Get the compile unit from the cache or create a new
51/// one if necessary. This returns null for invalid source locations.
52llvm::DICompileUnit CGDebugInfo::getOrCreateCompileUnit(SourceLocation Loc) {
53  // Get source file information.
54  const char *FileName =  "<unknown>";
55  SourceManager &SM = M->getContext().getSourceManager();
56  unsigned FID = 0;
57  if (Loc.isValid()) {
58    PresumedLoc PLoc = SM.getPresumedLoc(Loc);
59    FileName = PLoc.getFilename();
60    FID = PLoc.getIncludeLoc().getRawEncoding();
61  }
62
63  // See if this compile unit has been used before.
64  llvm::DICompileUnit &Unit = CompileUnitCache[FID];
65  if (!Unit.isNull()) return Unit;
66
67  // Get absolute path name.
68  llvm::sys::Path AbsFileName(FileName);
69  if (!AbsFileName.isAbsolute()) {
70    llvm::sys::Path tmp = llvm::sys::Path::GetCurrentDirectory();
71    tmp.appendComponent(FileName);
72    AbsFileName = tmp;
73  }
74
75  // See if thie compile unit is representing main source file. Each source
76  // file has corresponding compile unit. There is only one main source
77  // file at a time.
78  bool isMain = false;
79  const LangOptions &LO = M->getLangOptions();
80  const char *MainFileName = LO.getMainFileName();
81  if (isMainCompileUnitCreated == false) {
82    if (MainFileName) {
83      if (!strcmp(AbsFileName.getLast().c_str(), MainFileName))
84        isMain = true;
85    } else {
86      if (Loc.isValid() && SM.isFromMainFile(Loc))
87        isMain = true;
88    }
89    if (isMain)
90      isMainCompileUnitCreated = true;
91  }
92
93  unsigned LangTag;
94  if (LO.CPlusPlus) {
95    if (LO.ObjC1)
96      LangTag = llvm::dwarf::DW_LANG_ObjC_plus_plus;
97    else
98      LangTag = llvm::dwarf::DW_LANG_C_plus_plus;
99  } else if (LO.ObjC1) {
100    LangTag = llvm::dwarf::DW_LANG_ObjC;
101  } else if (LO.C99) {
102    LangTag = llvm::dwarf::DW_LANG_C99;
103  } else {
104    LangTag = llvm::dwarf::DW_LANG_C89;
105  }
106
107  std::string Producer = "clang 1.0";// FIXME: clang version.
108  bool isOptimized = LO.Optimize;
109  const char *Flags = "";   // FIXME: Encode command line options.
110
111  // Figure out which version of the ObjC runtime we have.
112  unsigned RuntimeVers = 0;
113  if (LO.ObjC1)
114    RuntimeVers = LO.ObjCNonFragileABI ? 2 : 1;
115
116  // Create new compile unit.
117  return Unit = DebugFactory.CreateCompileUnit(LangTag, AbsFileName.getLast(),
118                                               AbsFileName.getDirname(),
119                                               Producer, isMain, isOptimized,
120                                               Flags, RuntimeVers);
121}
122
123/// CreateType - Get the Basic type from the cache or create a new
124/// one if necessary.
125llvm::DIType CGDebugInfo::CreateType(const BuiltinType *BT,
126                                     llvm::DICompileUnit Unit) {
127  unsigned Encoding = 0;
128  switch (BT->getKind()) {
129  default:
130  case BuiltinType::Void:
131    return llvm::DIType();
132  case BuiltinType::UChar:
133  case BuiltinType::Char_U: Encoding = llvm::dwarf::DW_ATE_unsigned_char; break;
134  case BuiltinType::Char_S:
135  case BuiltinType::SChar: Encoding = llvm::dwarf::DW_ATE_signed_char; break;
136  case BuiltinType::UShort:
137  case BuiltinType::UInt:
138  case BuiltinType::ULong:
139  case BuiltinType::ULongLong: Encoding = llvm::dwarf::DW_ATE_unsigned; break;
140  case BuiltinType::Short:
141  case BuiltinType::Int:
142  case BuiltinType::Long:
143  case BuiltinType::LongLong:  Encoding = llvm::dwarf::DW_ATE_signed; break;
144  case BuiltinType::Bool:      Encoding = llvm::dwarf::DW_ATE_boolean; break;
145  case BuiltinType::Float:
146  case BuiltinType::Double:    Encoding = llvm::dwarf::DW_ATE_float; break;
147  }
148  // Bit size, align and offset of the type.
149  uint64_t Size = M->getContext().getTypeSize(BT);
150  uint64_t Align = M->getContext().getTypeAlign(BT);
151  uint64_t Offset = 0;
152
153  return DebugFactory.CreateBasicType(Unit, BT->getName(), Unit, 0, Size, Align,
154                                      Offset, /*flags*/ 0, Encoding);
155}
156
157llvm::DIType CGDebugInfo::CreateType(const ComplexType *Ty,
158                                     llvm::DICompileUnit Unit) {
159  // Bit size, align and offset of the type.
160  unsigned Encoding = llvm::dwarf::DW_ATE_complex_float;
161  if (Ty->isComplexIntegerType())
162    Encoding = llvm::dwarf::DW_ATE_lo_user;
163
164  uint64_t Size = M->getContext().getTypeSize(Ty);
165  uint64_t Align = M->getContext().getTypeAlign(Ty);
166  uint64_t Offset = 0;
167
168  return DebugFactory.CreateBasicType(Unit, "complex",
169                                      Unit, 0, Size, Align,
170                                      Offset, /*flags*/ 0, Encoding);
171}
172
173/// getOrCreateCVRType - Get the CVR qualified type from the cache or create
174/// a new one if necessary.
175llvm::DIType CGDebugInfo::CreateCVRType(QualType Ty, llvm::DICompileUnit Unit) {
176  // We will create one Derived type for one qualifier and recurse to handle any
177  // additional ones.
178  llvm::DIType FromTy;
179  unsigned Tag;
180  if (Ty.isConstQualified()) {
181    Tag = llvm::dwarf::DW_TAG_const_type;
182    Ty.removeConst();
183    FromTy = getOrCreateType(Ty, Unit);
184  } else if (Ty.isVolatileQualified()) {
185    Tag = llvm::dwarf::DW_TAG_volatile_type;
186    Ty.removeVolatile();
187    FromTy = getOrCreateType(Ty, Unit);
188  } else {
189    assert(Ty.isRestrictQualified() && "Unknown type qualifier for debug info");
190    Tag = llvm::dwarf::DW_TAG_restrict_type;
191    Ty.removeRestrict();
192    FromTy = getOrCreateType(Ty, Unit);
193  }
194
195  // No need to fill in the Name, Line, Size, Alignment, Offset in case of
196  // CVR derived types.
197  return DebugFactory.CreateDerivedType(Tag, Unit, "", llvm::DICompileUnit(),
198                                        0, 0, 0, 0, 0, FromTy);
199}
200
201llvm::DIType CGDebugInfo::CreateType(const PointerType *Ty,
202                                     llvm::DICompileUnit Unit) {
203  llvm::DIType EltTy = getOrCreateType(Ty->getPointeeType(), Unit);
204
205  // Bit size, align and offset of the type.
206  uint64_t Size = M->getContext().getTypeSize(Ty);
207  uint64_t Align = M->getContext().getTypeAlign(Ty);
208
209  return DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_pointer_type, Unit,
210                                        "", llvm::DICompileUnit(),
211                                        0, Size, Align, 0, 0, EltTy);
212}
213
214llvm::DIType CGDebugInfo::CreateType(const BlockPointerType *Ty,
215                                     llvm::DICompileUnit Unit) {
216  if (BlockLiteralGenericSet)
217    return BlockLiteralGeneric;
218
219  llvm::DICompileUnit DefUnit;
220  unsigned Tag = llvm::dwarf::DW_TAG_structure_type;
221
222  llvm::SmallVector<llvm::DIDescriptor, 5> EltTys;
223
224  llvm::DIType FieldTy;
225
226  QualType FType;
227  uint64_t FieldSize, FieldOffset;
228  unsigned FieldAlign;
229
230  llvm::DIArray Elements;
231  llvm::DIType EltTy, DescTy;
232
233  FieldOffset = 0;
234  FType = M->getContext().UnsignedLongTy;
235  FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
236  FieldSize = M->getContext().getTypeSize(FType);
237  FieldAlign = M->getContext().getTypeAlign(FType);
238  FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
239                                           "reserved", DefUnit,
240                                           0, FieldSize, FieldAlign,
241                                           FieldOffset, 0, FieldTy);
242  EltTys.push_back(FieldTy);
243
244  FieldOffset += FieldSize;
245  FType = M->getContext().UnsignedLongTy;
246  FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
247  FieldSize = M->getContext().getTypeSize(FType);
248  FieldAlign = M->getContext().getTypeAlign(FType);
249  FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
250                                           "Size", DefUnit,
251                                           0, FieldSize, FieldAlign,
252                                           FieldOffset, 0, FieldTy);
253  EltTys.push_back(FieldTy);
254
255  FieldOffset += FieldSize;
256  Elements = DebugFactory.GetOrCreateArray(&EltTys[0], EltTys.size());
257  EltTys.clear();
258
259  EltTy = DebugFactory.CreateCompositeType(Tag, Unit, "__block_descriptor",
260                                           DefUnit, 0, FieldOffset, 0, 0, 0,
261                                           llvm::DIType(), Elements);
262
263  // Bit size, align and offset of the type.
264  uint64_t Size = M->getContext().getTypeSize(Ty);
265  uint64_t Align = M->getContext().getTypeAlign(Ty);
266
267  DescTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_pointer_type,
268                                          Unit, "", llvm::DICompileUnit(),
269                                          0, Size, Align, 0, 0, EltTy);
270
271  FieldOffset = 0;
272  FType = M->getContext().getPointerType(M->getContext().VoidTy);
273  FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
274  FieldSize = M->getContext().getTypeSize(FType);
275  FieldAlign = M->getContext().getTypeAlign(FType);
276  FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
277                                           "__isa", DefUnit,
278                                           0, FieldSize, FieldAlign,
279                                           FieldOffset, 0, FieldTy);
280  EltTys.push_back(FieldTy);
281
282  FieldOffset += FieldSize;
283  FType = M->getContext().IntTy;
284  FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
285  FieldSize = M->getContext().getTypeSize(FType);
286  FieldAlign = M->getContext().getTypeAlign(FType);
287  FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
288                                           "__flags", DefUnit,
289                                           0, FieldSize, FieldAlign,
290                                           FieldOffset, 0, FieldTy);
291  EltTys.push_back(FieldTy);
292
293  FieldOffset += FieldSize;
294  FType = M->getContext().IntTy;
295  FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
296  FieldSize = M->getContext().getTypeSize(FType);
297  FieldAlign = M->getContext().getTypeAlign(FType);
298  FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
299                                           "__reserved", DefUnit,
300                                           0, FieldSize, FieldAlign,
301                                           FieldOffset, 0, FieldTy);
302  EltTys.push_back(FieldTy);
303
304  FieldOffset += FieldSize;
305  FType = M->getContext().getPointerType(M->getContext().VoidTy);
306  FieldTy = CGDebugInfo::getOrCreateType(FType, Unit);
307  FieldSize = M->getContext().getTypeSize(FType);
308  FieldAlign = M->getContext().getTypeAlign(FType);
309  FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
310                                           "__FuncPtr", DefUnit,
311                                           0, FieldSize, FieldAlign,
312                                           FieldOffset, 0, FieldTy);
313  EltTys.push_back(FieldTy);
314
315  FieldOffset += FieldSize;
316  FType = M->getContext().getPointerType(M->getContext().VoidTy);
317  FieldTy = DescTy;
318  FieldSize = M->getContext().getTypeSize(Ty);
319  FieldAlign = M->getContext().getTypeAlign(Ty);
320  FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
321                                           "__descriptor", DefUnit,
322                                           0, FieldSize, FieldAlign,
323                                           FieldOffset, 0, FieldTy);
324  EltTys.push_back(FieldTy);
325
326  FieldOffset += FieldSize;
327  Elements = DebugFactory.GetOrCreateArray(&EltTys[0], EltTys.size());
328
329  EltTy = DebugFactory.CreateCompositeType(Tag, Unit, "__block_literal_generic",
330                                           DefUnit, 0, FieldOffset, 0, 0, 0,
331                                           llvm::DIType(), Elements);
332
333  BlockLiteralGenericSet = true;
334  BlockLiteralGeneric
335    = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_pointer_type, Unit,
336                                     "", llvm::DICompileUnit(),
337                                     0, Size, Align, 0, 0, EltTy);
338  return BlockLiteralGeneric;
339}
340
341llvm::DIType CGDebugInfo::CreateType(const TypedefType *Ty,
342                                     llvm::DICompileUnit Unit) {
343  // Typedefs are derived from some other type.  If we have a typedef of a
344  // typedef, make sure to emit the whole chain.
345  llvm::DIType Src = getOrCreateType(Ty->getDecl()->getUnderlyingType(), Unit);
346
347  // We don't set size information, but do specify where the typedef was
348  // declared.
349  std::string TyName = Ty->getDecl()->getNameAsString();
350  SourceLocation DefLoc = Ty->getDecl()->getLocation();
351  llvm::DICompileUnit DefUnit = getOrCreateCompileUnit(DefLoc);
352
353  SourceManager &SM = M->getContext().getSourceManager();
354  PresumedLoc PLoc = SM.getPresumedLoc(DefLoc);
355  unsigned Line = PLoc.isInvalid() ? 0 : PLoc.getLine();
356
357  return DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_typedef, Unit,
358                                        TyName, DefUnit, Line, 0, 0, 0, 0, Src);
359}
360
361llvm::DIType CGDebugInfo::CreateType(const FunctionType *Ty,
362                                     llvm::DICompileUnit Unit) {
363  llvm::SmallVector<llvm::DIDescriptor, 16> EltTys;
364
365  // Add the result type at least.
366  EltTys.push_back(getOrCreateType(Ty->getResultType(), Unit));
367
368  // Set up remainder of arguments if there is a prototype.
369  // FIXME: IF NOT, HOW IS THIS REPRESENTED?  llvm-gcc doesn't represent '...'!
370  if (const FunctionProtoType *FTP = dyn_cast<FunctionProtoType>(Ty)) {
371    for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i)
372      EltTys.push_back(getOrCreateType(FTP->getArgType(i), Unit));
373  } else {
374    // FIXME: Handle () case in C.  llvm-gcc doesn't do it either.
375  }
376
377  llvm::DIArray EltTypeArray =
378    DebugFactory.GetOrCreateArray(&EltTys[0], EltTys.size());
379
380  return DebugFactory.CreateCompositeType(llvm::dwarf::DW_TAG_subroutine_type,
381                                          Unit, "", llvm::DICompileUnit(),
382                                          0, 0, 0, 0, 0,
383                                          llvm::DIType(), EltTypeArray);
384}
385
386/// CreateType - get structure or union type.
387llvm::DIType CGDebugInfo::CreateType(const RecordType *Ty,
388                                     llvm::DICompileUnit Unit) {
389  RecordDecl *Decl = Ty->getDecl();
390
391  unsigned Tag;
392  if (Decl->isStruct())
393    Tag = llvm::dwarf::DW_TAG_structure_type;
394  else if (Decl->isUnion())
395    Tag = llvm::dwarf::DW_TAG_union_type;
396  else {
397    assert(Decl->isClass() && "Unknown RecordType!");
398    Tag = llvm::dwarf::DW_TAG_class_type;
399  }
400
401  SourceManager &SM = M->getContext().getSourceManager();
402
403  // Get overall information about the record type for the debug info.
404  std::string Name = Decl->getNameAsString();
405
406  PresumedLoc PLoc = SM.getPresumedLoc(Decl->getLocation());
407  llvm::DICompileUnit DefUnit;
408  unsigned Line = 0;
409  if (!PLoc.isInvalid()) {
410    DefUnit = getOrCreateCompileUnit(Decl->getLocation());
411    Line = PLoc.getLine();
412  }
413
414  // Records and classes and unions can all be recursive.  To handle them, we
415  // first generate a debug descriptor for the struct as a forward declaration.
416  // Then (if it is a definition) we go through and get debug info for all of
417  // its members.  Finally, we create a descriptor for the complete type (which
418  // may refer to the forward decl if the struct is recursive) and replace all
419  // uses of the forward declaration with the final definition.
420  llvm::DIType FwdDecl =
421    DebugFactory.CreateCompositeType(Tag, Unit, Name, DefUnit, Line, 0, 0, 0, 0,
422                                     llvm::DIType(), llvm::DIArray());
423
424  // If this is just a forward declaration, return it.
425  if (!Decl->getDefinition(M->getContext()))
426    return FwdDecl;
427
428  // Otherwise, insert it into the TypeCache so that recursive uses will find
429  // it.
430  TypeCache[QualType(Ty, 0).getAsOpaquePtr()] = FwdDecl;
431
432  // Convert all the elements.
433  llvm::SmallVector<llvm::DIDescriptor, 16> EltTys;
434
435  const ASTRecordLayout &RL = M->getContext().getASTRecordLayout(Decl);
436
437  unsigned FieldNo = 0;
438  for (RecordDecl::field_iterator I = Decl->field_begin(M->getContext()),
439                                  E = Decl->field_end(M->getContext());
440       I != E; ++I, ++FieldNo) {
441    FieldDecl *Field = *I;
442    llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
443
444    std::string FieldName = Field->getNameAsString();
445
446    // Ignore unnamed fields.
447    if (FieldName.empty())
448      continue;
449
450    // Get the location for the field.
451    SourceLocation FieldDefLoc = Field->getLocation();
452    PresumedLoc PLoc = SM.getPresumedLoc(FieldDefLoc);
453    llvm::DICompileUnit FieldDefUnit;
454    unsigned FieldLine = 0;
455
456    if (!PLoc.isInvalid()) {
457      FieldDefUnit = getOrCreateCompileUnit(FieldDefLoc);
458      FieldLine = PLoc.getLine();
459    }
460
461    QualType FType = Field->getType();
462    uint64_t FieldSize = 0;
463    unsigned FieldAlign = 0;
464    if (!FType->isIncompleteArrayType()) {
465
466      // Bit size, align and offset of the type.
467      FieldSize = M->getContext().getTypeSize(FType);
468      Expr *BitWidth = Field->getBitWidth();
469      if (BitWidth)
470        FieldSize = BitWidth->EvaluateAsInt(M->getContext()).getZExtValue();
471
472      FieldAlign =  M->getContext().getTypeAlign(FType);
473    }
474
475    uint64_t FieldOffset = RL.getFieldOffset(FieldNo);
476
477    // Create a DW_TAG_member node to remember the offset of this field in the
478    // struct.  FIXME: This is an absolutely insane way to capture this
479    // information.  When we gut debug info, this should be fixed.
480    FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
481                                             FieldName, FieldDefUnit,
482                                             FieldLine, FieldSize, FieldAlign,
483                                             FieldOffset, 0, FieldTy);
484    EltTys.push_back(FieldTy);
485  }
486
487  llvm::DIArray Elements =
488    DebugFactory.GetOrCreateArray(&EltTys[0], EltTys.size());
489
490  // Bit size, align and offset of the type.
491  uint64_t Size = M->getContext().getTypeSize(Ty);
492  uint64_t Align = M->getContext().getTypeAlign(Ty);
493
494  llvm::DIType RealDecl =
495    DebugFactory.CreateCompositeType(Tag, Unit, Name, DefUnit, Line, Size,
496                                     Align, 0, 0, llvm::DIType(), Elements);
497
498  // Now that we have a real decl for the struct, replace anything using the
499  // old decl with the new one.  This will recursively update the debug info.
500  FwdDecl.getGV()->replaceAllUsesWith(RealDecl.getGV());
501  FwdDecl.getGV()->eraseFromParent();
502
503  return RealDecl;
504}
505
506/// CreateType - get objective-c interface type.
507llvm::DIType CGDebugInfo::CreateType(const ObjCInterfaceType *Ty,
508                                     llvm::DICompileUnit Unit) {
509  ObjCInterfaceDecl *Decl = Ty->getDecl();
510
511  unsigned Tag = llvm::dwarf::DW_TAG_structure_type;
512  SourceManager &SM = M->getContext().getSourceManager();
513
514  // Get overall information about the record type for the debug info.
515  std::string Name = Decl->getNameAsString();
516
517  llvm::DICompileUnit DefUnit = getOrCreateCompileUnit(Decl->getLocation());
518  PresumedLoc PLoc = SM.getPresumedLoc(Decl->getLocation());
519  unsigned Line = PLoc.isInvalid() ? 0 : PLoc.getLine();
520
521
522  unsigned RuntimeLang = DefUnit.getRunTimeVersion();
523
524  // To handle recursive interface, we
525  // first generate a debug descriptor for the struct as a forward declaration.
526  // Then (if it is a definition) we go through and get debug info for all of
527  // its members.  Finally, we create a descriptor for the complete type (which
528  // may refer to the forward decl if the struct is recursive) and replace all
529  // uses of the forward declaration with the final definition.
530  llvm::DIType FwdDecl =
531    DebugFactory.CreateCompositeType(Tag, Unit, Name, DefUnit, Line, 0, 0, 0, 0,
532                                     llvm::DIType(), llvm::DIArray(),
533                                     RuntimeLang);
534
535  // If this is just a forward declaration, return it.
536  if (Decl->isForwardDecl())
537    return FwdDecl;
538
539  // Otherwise, insert it into the TypeCache so that recursive uses will find
540  // it.
541  TypeCache[QualType(Ty, 0).getAsOpaquePtr()] = FwdDecl;
542
543  // Convert all the elements.
544  llvm::SmallVector<llvm::DIDescriptor, 16> EltTys;
545
546  ObjCInterfaceDecl *SClass = Decl->getSuperClass();
547  if (SClass) {
548    llvm::DIType SClassTy =
549      getOrCreateType(M->getContext().getObjCInterfaceType(SClass), Unit);
550    llvm::DIType InhTag =
551      DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_inheritance,
552                                     Unit, "", llvm::DICompileUnit(), 0, 0, 0,
553                                     0 /* offset */, 0, SClassTy);
554    EltTys.push_back(InhTag);
555  }
556
557  const ASTRecordLayout &RL = M->getContext().getASTObjCInterfaceLayout(Decl);
558
559  unsigned FieldNo = 0;
560  for (ObjCInterfaceDecl::ivar_iterator I = Decl->ivar_begin(),
561         E = Decl->ivar_end();  I != E; ++I, ++FieldNo) {
562    ObjCIvarDecl *Field = *I;
563    llvm::DIType FieldTy = getOrCreateType(Field->getType(), Unit);
564
565    std::string FieldName = Field->getNameAsString();
566
567    // Ignore unnamed fields.
568    if (FieldName.empty())
569      continue;
570
571    // Get the location for the field.
572    SourceLocation FieldDefLoc = Field->getLocation();
573    llvm::DICompileUnit FieldDefUnit = getOrCreateCompileUnit(FieldDefLoc);
574    PresumedLoc PLoc = SM.getPresumedLoc(FieldDefLoc);
575    unsigned FieldLine = PLoc.isInvalid() ? 0 : PLoc.getLine();
576
577
578    QualType FType = Field->getType();
579    uint64_t FieldSize = 0;
580    unsigned FieldAlign = 0;
581
582    if (!FType->isIncompleteArrayType()) {
583
584      // Bit size, align and offset of the type.
585      FieldSize = M->getContext().getTypeSize(FType);
586      Expr *BitWidth = Field->getBitWidth();
587      if (BitWidth)
588        FieldSize = BitWidth->EvaluateAsInt(M->getContext()).getZExtValue();
589
590      FieldAlign =  M->getContext().getTypeAlign(FType);
591    }
592
593    uint64_t FieldOffset = RL.getFieldOffset(FieldNo);
594
595    unsigned Flags = 0;
596    if (Field->getAccessControl() == ObjCIvarDecl::Protected)
597      Flags = llvm::DIType::FlagProtected;
598    else if (Field->getAccessControl() == ObjCIvarDecl::Private)
599      Flags = llvm::DIType::FlagPrivate;
600
601    // Create a DW_TAG_member node to remember the offset of this field in the
602    // struct.  FIXME: This is an absolutely insane way to capture this
603    // information.  When we gut debug info, this should be fixed.
604    FieldTy = DebugFactory.CreateDerivedType(llvm::dwarf::DW_TAG_member, Unit,
605                                             FieldName, FieldDefUnit,
606                                             FieldLine, FieldSize, FieldAlign,
607                                             FieldOffset, Flags, FieldTy);
608    EltTys.push_back(FieldTy);
609  }
610
611  llvm::DIArray Elements =
612    DebugFactory.GetOrCreateArray(&EltTys[0], EltTys.size());
613
614  // Bit size, align and offset of the type.
615  uint64_t Size = M->getContext().getTypeSize(Ty);
616  uint64_t Align = M->getContext().getTypeAlign(Ty);
617
618  llvm::DIType RealDecl =
619    DebugFactory.CreateCompositeType(Tag, Unit, Name, DefUnit, Line, Size,
620                                     Align, 0, 0, llvm::DIType(), Elements,
621                                     RuntimeLang);
622
623  // Now that we have a real decl for the struct, replace anything using the
624  // old decl with the new one.  This will recursively update the debug info.
625  FwdDecl.getGV()->replaceAllUsesWith(RealDecl.getGV());
626  FwdDecl.getGV()->eraseFromParent();
627
628  return RealDecl;
629}
630
631llvm::DIType CGDebugInfo::CreateType(const EnumType *Ty,
632                                     llvm::DICompileUnit Unit) {
633  EnumDecl *Decl = Ty->getDecl();
634
635  llvm::SmallVector<llvm::DIDescriptor, 32> Enumerators;
636
637  // Create DIEnumerator elements for each enumerator.
638  for (EnumDecl::enumerator_iterator
639         Enum = Decl->enumerator_begin(M->getContext()),
640         EnumEnd = Decl->enumerator_end(M->getContext());
641       Enum != EnumEnd; ++Enum) {
642    Enumerators.push_back(DebugFactory.CreateEnumerator(Enum->getNameAsString(),
643                                            Enum->getInitVal().getZExtValue()));
644  }
645
646  // Return a CompositeType for the enum itself.
647  llvm::DIArray EltArray =
648    DebugFactory.GetOrCreateArray(&Enumerators[0], Enumerators.size());
649
650  std::string EnumName = Decl->getNameAsString();
651  SourceLocation DefLoc = Decl->getLocation();
652  llvm::DICompileUnit DefUnit = getOrCreateCompileUnit(DefLoc);
653  SourceManager &SM = M->getContext().getSourceManager();
654  PresumedLoc PLoc = SM.getPresumedLoc(DefLoc);
655  unsigned Line = PLoc.isInvalid() ? 0 : PLoc.getLine();
656
657
658  // Size and align of the type.
659  uint64_t Size = 0;
660  unsigned Align = 0;
661  if (!Ty->isIncompleteType()) {
662    Size = M->getContext().getTypeSize(Ty);
663    Align = M->getContext().getTypeAlign(Ty);
664  }
665
666  return DebugFactory.CreateCompositeType(llvm::dwarf::DW_TAG_enumeration_type,
667                                          Unit, EnumName, DefUnit, Line,
668                                          Size, Align, 0, 0,
669                                          llvm::DIType(), EltArray);
670}
671
672llvm::DIType CGDebugInfo::CreateType(const TagType *Ty,
673                                     llvm::DICompileUnit Unit) {
674  if (const RecordType *RT = dyn_cast<RecordType>(Ty))
675    return CreateType(RT, Unit);
676  else if (const EnumType *ET = dyn_cast<EnumType>(Ty))
677    return CreateType(ET, Unit);
678
679  return llvm::DIType();
680}
681
682llvm::DIType CGDebugInfo::CreateType(const ArrayType *Ty,
683                                     llvm::DICompileUnit Unit) {
684  uint64_t Size;
685  uint64_t Align;
686
687
688  // FIXME: make getTypeAlign() aware of VLAs and incomplete array types
689  if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(Ty)) {
690    Size = 0;
691    Align =
692      M->getContext().getTypeAlign(M->getContext().getBaseElementType(VAT));
693  } else if (Ty->isIncompleteArrayType()) {
694    Size = 0;
695    Align = M->getContext().getTypeAlign(Ty->getElementType());
696  } else {
697    // Size and align of the whole array, not the element type.
698    Size = M->getContext().getTypeSize(Ty);
699    Align = M->getContext().getTypeAlign(Ty);
700  }
701
702  // Add the dimensions of the array.  FIXME: This loses CV qualifiers from
703  // interior arrays, do we care?  Why aren't nested arrays represented the
704  // obvious/recursive way?
705  llvm::SmallVector<llvm::DIDescriptor, 8> Subscripts;
706  QualType EltTy(Ty, 0);
707  while ((Ty = dyn_cast<ArrayType>(EltTy))) {
708    uint64_t Upper = 0;
709    if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(Ty))
710      Upper = CAT->getSize().getZExtValue() - 1;
711    // FIXME: Verify this is right for VLAs.
712    Subscripts.push_back(DebugFactory.GetOrCreateSubrange(0, Upper));
713    EltTy = Ty->getElementType();
714  }
715
716  llvm::DIArray SubscriptArray =
717    DebugFactory.GetOrCreateArray(&Subscripts[0], Subscripts.size());
718
719  return DebugFactory.CreateCompositeType(llvm::dwarf::DW_TAG_array_type,
720                                          Unit, "", llvm::DICompileUnit(),
721                                          0, Size, Align, 0, 0,
722                                          getOrCreateType(EltTy, Unit),
723                                          SubscriptArray);
724}
725
726
727/// getOrCreateType - Get the type from the cache or create a new
728/// one if necessary.
729llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty,
730                                          llvm::DICompileUnit Unit) {
731  if (Ty.isNull())
732    return llvm::DIType();
733
734  // Check to see if the compile unit already has created this type.
735  llvm::DIType &Slot = TypeCache[Ty.getAsOpaquePtr()];
736  if (!Slot.isNull()) return Slot;
737
738  // Handle CVR qualifiers, which recursively handles what they refer to.
739  if (Ty.getCVRQualifiers())
740    return Slot = CreateCVRType(Ty, Unit);
741
742  // Work out details of type.
743  switch (Ty->getTypeClass()) {
744#define TYPE(Class, Base)
745#define ABSTRACT_TYPE(Class, Base)
746#define NON_CANONICAL_TYPE(Class, Base)
747#define DEPENDENT_TYPE(Class, Base) case Type::Class:
748#include "clang/AST/TypeNodes.def"
749    assert(false && "Dependent types cannot show up in debug information");
750
751  case Type::LValueReference:
752  case Type::RValueReference:
753  case Type::Vector:
754  case Type::ExtVector:
755  case Type::ExtQual:
756  case Type::FixedWidthInt:
757  case Type::MemberPointer:
758  case Type::TemplateSpecialization:
759  case Type::QualifiedName:
760    // Unsupported types
761    return llvm::DIType();
762  case Type::ObjCQualifiedId:   // Encode id<p> in debug info just like id.
763    return Slot = getOrCreateType(M->getContext().getObjCIdType(), Unit);
764
765  case Type::ObjCQualifiedInterface:  // Drop protocols from interface.
766  case Type::ObjCInterface:
767    return Slot = CreateType(cast<ObjCInterfaceType>(Ty), Unit);
768  case Type::Builtin: return Slot = CreateType(cast<BuiltinType>(Ty), Unit);
769  case Type::Complex: return Slot = CreateType(cast<ComplexType>(Ty), Unit);
770  case Type::Pointer: return Slot = CreateType(cast<PointerType>(Ty), Unit);
771  case Type::BlockPointer:
772    return Slot = CreateType(cast<BlockPointerType>(Ty), Unit);
773  case Type::Typedef: return Slot = CreateType(cast<TypedefType>(Ty), Unit);
774  case Type::Record:
775  case Type::Enum:
776    return Slot = CreateType(cast<TagType>(Ty), Unit);
777  case Type::FunctionProto:
778  case Type::FunctionNoProto:
779    return Slot = CreateType(cast<FunctionType>(Ty), Unit);
780
781  case Type::ConstantArray:
782  case Type::VariableArray:
783  case Type::IncompleteArray:
784    return Slot = CreateType(cast<ArrayType>(Ty), Unit);
785  case Type::TypeOfExpr:
786    return Slot = getOrCreateType(cast<TypeOfExprType>(Ty)->getUnderlyingExpr()
787                                  ->getType(), Unit);
788  case Type::TypeOf:
789    return Slot = getOrCreateType(cast<TypeOfType>(Ty)->getUnderlyingType(),
790                                  Unit);
791  }
792
793  return Slot;
794}
795
796/// EmitFunctionStart - Constructs the debug code for entering a function -
797/// "llvm.dbg.func.start.".
798void CGDebugInfo::EmitFunctionStart(const char *Name, QualType ReturnType,
799                                    llvm::Function *Fn,
800                                    CGBuilderTy &Builder) {
801  const char *LinkageName = Name;
802
803  // Skip the asm prefix if it exists.
804  //
805  // FIXME: This should probably be the unmangled name?
806  if (Name[0] == '\01')
807    ++Name;
808
809  // FIXME: Why is this using CurLoc???
810  llvm::DICompileUnit Unit = getOrCreateCompileUnit(CurLoc);
811  SourceManager &SM = M->getContext().getSourceManager();
812  unsigned LineNo = SM.getPresumedLoc(CurLoc).getLine();
813
814  llvm::DISubprogram SP =
815    DebugFactory.CreateSubprogram(Unit, Name, Name, LinkageName, Unit, LineNo,
816                                  getOrCreateType(ReturnType, Unit),
817                                  Fn->hasInternalLinkage(), true/*definition*/);
818
819  DebugFactory.InsertSubprogramStart(SP, Builder.GetInsertBlock());
820
821  // Push function on region stack.
822  RegionStack.push_back(SP);
823}
824
825
826void CGDebugInfo::EmitStopPoint(llvm::Function *Fn, CGBuilderTy &Builder) {
827  if (CurLoc.isInvalid() || CurLoc.isMacroID()) return;
828
829  // Don't bother if things are the same as last time.
830  SourceManager &SM = M->getContext().getSourceManager();
831  if (CurLoc == PrevLoc
832       || (SM.getInstantiationLineNumber(CurLoc) ==
833           SM.getInstantiationLineNumber(PrevLoc)
834           && SM.isFromSameFile(CurLoc, PrevLoc)))
835    return;
836
837  // Update last state.
838  PrevLoc = CurLoc;
839
840  // Get the appropriate compile unit.
841  llvm::DICompileUnit Unit = getOrCreateCompileUnit(CurLoc);
842  PresumedLoc PLoc = SM.getPresumedLoc(CurLoc);
843  DebugFactory.InsertStopPoint(Unit, PLoc.getLine(), PLoc.getColumn(),
844                               Builder.GetInsertBlock());
845}
846
847/// EmitRegionStart- Constructs the debug code for entering a declarative
848/// region - "llvm.dbg.region.start.".
849void CGDebugInfo::EmitRegionStart(llvm::Function *Fn, CGBuilderTy &Builder) {
850  llvm::DIDescriptor D;
851  if (!RegionStack.empty())
852    D = RegionStack.back();
853  D = DebugFactory.CreateBlock(D);
854  RegionStack.push_back(D);
855  DebugFactory.InsertRegionStart(D, Builder.GetInsertBlock());
856}
857
858/// EmitRegionEnd - Constructs the debug code for exiting a declarative
859/// region - "llvm.dbg.region.end."
860void CGDebugInfo::EmitRegionEnd(llvm::Function *Fn, CGBuilderTy &Builder) {
861  assert(!RegionStack.empty() && "Region stack mismatch, stack empty!");
862
863  // Provide an region stop point.
864  EmitStopPoint(Fn, Builder);
865
866  DebugFactory.InsertRegionEnd(RegionStack.back(), Builder.GetInsertBlock());
867  RegionStack.pop_back();
868}
869
870/// EmitDeclare - Emit local variable declaration debug info.
871void CGDebugInfo::EmitDeclare(const VarDecl *Decl, unsigned Tag,
872                              llvm::Value *Storage, CGBuilderTy &Builder) {
873  assert(!RegionStack.empty() && "Region stack mismatch, stack empty!");
874
875  // Do not emit variable debug information while generating optimized code.
876  // The llvm optimizer and code generator are not yet ready to support
877  // optimized code debugging.
878  const CompileOptions &CO = M->getCompileOpts();
879  if (CO.OptimizationLevel)
880    return;
881
882  llvm::DICompileUnit Unit = getOrCreateCompileUnit(Decl->getLocation());
883  llvm::DIType Ty = getOrCreateType(Decl->getType(), Unit);
884
885  // Get location information.
886  SourceManager &SM = M->getContext().getSourceManager();
887  PresumedLoc PLoc = SM.getPresumedLoc(Decl->getLocation());
888  unsigned Line = 0;
889  if (!PLoc.isInvalid())
890    Line = PLoc.getLine();
891  else
892    Unit = llvm::DICompileUnit();
893
894
895  // Create the descriptor for the variable.
896  llvm::DIVariable D =
897    DebugFactory.CreateVariable(Tag, RegionStack.back(),Decl->getNameAsString(),
898                                Unit, Line, Ty);
899  // Insert an llvm.dbg.declare into the current block.
900  DebugFactory.InsertDeclare(Storage, D, Builder.GetInsertBlock());
901}
902
903void CGDebugInfo::EmitDeclareOfAutoVariable(const VarDecl *Decl,
904                                            llvm::Value *Storage,
905                                            CGBuilderTy &Builder) {
906  EmitDeclare(Decl, llvm::dwarf::DW_TAG_auto_variable, Storage, Builder);
907}
908
909/// EmitDeclareOfArgVariable - Emit call to llvm.dbg.declare for an argument
910/// variable declaration.
911void CGDebugInfo::EmitDeclareOfArgVariable(const VarDecl *Decl, llvm::Value *AI,
912                                           CGBuilderTy &Builder) {
913  EmitDeclare(Decl, llvm::dwarf::DW_TAG_arg_variable, AI, Builder);
914}
915
916
917
918/// EmitGlobalVariable - Emit information about a global variable.
919void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
920                                     const VarDecl *Decl) {
921
922  // Do not emit variable debug information while generating optimized code.
923  // The llvm optimizer and code generator are not yet ready to support
924  // optimized code debugging.
925  const CompileOptions &CO = M->getCompileOpts();
926  if (CO.OptimizationLevel)
927    return;
928
929  // Create global variable debug descriptor.
930  llvm::DICompileUnit Unit = getOrCreateCompileUnit(Decl->getLocation());
931  SourceManager &SM = M->getContext().getSourceManager();
932  PresumedLoc PLoc = SM.getPresumedLoc(Decl->getLocation());
933  unsigned LineNo = PLoc.isInvalid() ? 0 : PLoc.getLine();
934
935  std::string Name = Decl->getNameAsString();
936
937  QualType T = Decl->getType();
938  if (T->isIncompleteArrayType()) {
939
940    // CodeGen turns int[] into int[1] so we'll do the same here.
941    llvm::APSInt ConstVal(32);
942
943    ConstVal = 1;
944    QualType ET = M->getContext().getAsArrayType(T)->getElementType();
945
946    T = M->getContext().getConstantArrayType(ET, ConstVal,
947                                           ArrayType::Normal, 0);
948  }
949
950  DebugFactory.CreateGlobalVariable(Unit, Name, Name, "", Unit, LineNo,
951                                    getOrCreateType(T, Unit),
952                                    Var->hasInternalLinkage(),
953                                    true/*definition*/, Var);
954}
955
956/// EmitGlobalVariable - Emit information about an objective-c interface.
957void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
958                                     ObjCInterfaceDecl *Decl) {
959  // Create global variable debug descriptor.
960  llvm::DICompileUnit Unit = getOrCreateCompileUnit(Decl->getLocation());
961  SourceManager &SM = M->getContext().getSourceManager();
962  PresumedLoc PLoc = SM.getPresumedLoc(Decl->getLocation());
963  unsigned LineNo = PLoc.isInvalid() ? 0 : PLoc.getLine();
964
965  std::string Name = Decl->getNameAsString();
966
967  QualType T = M->getContext().getObjCInterfaceType(Decl);
968  if (T->isIncompleteArrayType()) {
969
970    // CodeGen turns int[] into int[1] so we'll do the same here.
971    llvm::APSInt ConstVal(32);
972
973    ConstVal = 1;
974    QualType ET = M->getContext().getAsArrayType(T)->getElementType();
975
976    T = M->getContext().getConstantArrayType(ET, ConstVal,
977                                           ArrayType::Normal, 0);
978  }
979
980  DebugFactory.CreateGlobalVariable(Unit, Name, Name, "", Unit, LineNo,
981                                    getOrCreateType(T, Unit),
982                                    Var->hasInternalLinkage(),
983                                    true/*definition*/, Var);
984}
985
986