1//===--- NestedNameSpecifier.cpp - C++ nested name specifiers -----*- C++ -*-=//
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 defines the NestedNameSpecifier class, which represents
11//  a C++ nested-name-specifier.
12//
13//===----------------------------------------------------------------------===//
14#include "clang/AST/NestedNameSpecifier.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/Decl.h"
17#include "clang/AST/DeclCXX.h"
18#include "clang/AST/PrettyPrinter.h"
19#include "clang/AST/Type.h"
20#include "clang/AST/TypeLoc.h"
21#include "llvm/Support/raw_ostream.h"
22#include <cassert>
23
24using namespace clang;
25
26NestedNameSpecifier *
27NestedNameSpecifier::FindOrInsert(const ASTContext &Context,
28                                  const NestedNameSpecifier &Mockup) {
29  llvm::FoldingSetNodeID ID;
30  Mockup.Profile(ID);
31
32  void *InsertPos = 0;
33  NestedNameSpecifier *NNS
34    = Context.NestedNameSpecifiers.FindNodeOrInsertPos(ID, InsertPos);
35  if (!NNS) {
36    NNS = new (Context, 4) NestedNameSpecifier(Mockup);
37    Context.NestedNameSpecifiers.InsertNode(NNS, InsertPos);
38  }
39
40  return NNS;
41}
42
43NestedNameSpecifier *
44NestedNameSpecifier::Create(const ASTContext &Context,
45                            NestedNameSpecifier *Prefix, IdentifierInfo *II) {
46  assert(II && "Identifier cannot be NULL");
47  assert((!Prefix || Prefix->isDependent()) && "Prefix must be dependent");
48
49  NestedNameSpecifier Mockup;
50  Mockup.Prefix.setPointer(Prefix);
51  Mockup.Prefix.setInt(StoredIdentifier);
52  Mockup.Specifier = II;
53  return FindOrInsert(Context, Mockup);
54}
55
56NestedNameSpecifier *
57NestedNameSpecifier::Create(const ASTContext &Context,
58                            NestedNameSpecifier *Prefix, NamespaceDecl *NS) {
59  assert(NS && "Namespace cannot be NULL");
60  assert((!Prefix ||
61          (Prefix->getAsType() == 0 && Prefix->getAsIdentifier() == 0)) &&
62         "Broken nested name specifier");
63  NestedNameSpecifier Mockup;
64  Mockup.Prefix.setPointer(Prefix);
65  Mockup.Prefix.setInt(StoredNamespaceOrAlias);
66  Mockup.Specifier = NS;
67  return FindOrInsert(Context, Mockup);
68}
69
70NestedNameSpecifier *
71NestedNameSpecifier::Create(const ASTContext &Context,
72                            NestedNameSpecifier *Prefix,
73                            NamespaceAliasDecl *Alias) {
74  assert(Alias && "Namespace alias cannot be NULL");
75  assert((!Prefix ||
76          (Prefix->getAsType() == 0 && Prefix->getAsIdentifier() == 0)) &&
77         "Broken nested name specifier");
78  NestedNameSpecifier Mockup;
79  Mockup.Prefix.setPointer(Prefix);
80  Mockup.Prefix.setInt(StoredNamespaceOrAlias);
81  Mockup.Specifier = Alias;
82  return FindOrInsert(Context, Mockup);
83}
84
85NestedNameSpecifier *
86NestedNameSpecifier::Create(const ASTContext &Context,
87                            NestedNameSpecifier *Prefix,
88                            bool Template, const Type *T) {
89  assert(T && "Type cannot be NULL");
90  NestedNameSpecifier Mockup;
91  Mockup.Prefix.setPointer(Prefix);
92  Mockup.Prefix.setInt(Template? StoredTypeSpecWithTemplate : StoredTypeSpec);
93  Mockup.Specifier = const_cast<Type*>(T);
94  return FindOrInsert(Context, Mockup);
95}
96
97NestedNameSpecifier *
98NestedNameSpecifier::Create(const ASTContext &Context, IdentifierInfo *II) {
99  assert(II && "Identifier cannot be NULL");
100  NestedNameSpecifier Mockup;
101  Mockup.Prefix.setPointer(0);
102  Mockup.Prefix.setInt(StoredIdentifier);
103  Mockup.Specifier = II;
104  return FindOrInsert(Context, Mockup);
105}
106
107NestedNameSpecifier *
108NestedNameSpecifier::GlobalSpecifier(const ASTContext &Context) {
109  if (!Context.GlobalNestedNameSpecifier)
110    Context.GlobalNestedNameSpecifier = new (Context, 4) NestedNameSpecifier();
111  return Context.GlobalNestedNameSpecifier;
112}
113
114NestedNameSpecifier::SpecifierKind NestedNameSpecifier::getKind() const {
115  if (Specifier == 0)
116    return Global;
117
118  switch (Prefix.getInt()) {
119  case StoredIdentifier:
120    return Identifier;
121
122  case StoredNamespaceOrAlias:
123    return isa<NamespaceDecl>(static_cast<NamedDecl *>(Specifier))? Namespace
124                                                            : NamespaceAlias;
125
126  case StoredTypeSpec:
127    return TypeSpec;
128
129  case StoredTypeSpecWithTemplate:
130    return TypeSpecWithTemplate;
131  }
132
133  llvm_unreachable("Invalid NNS Kind!");
134}
135
136/// \brief Retrieve the namespace stored in this nested name
137/// specifier.
138NamespaceDecl *NestedNameSpecifier::getAsNamespace() const {
139  if (Prefix.getInt() == StoredNamespaceOrAlias)
140    return dyn_cast<NamespaceDecl>(static_cast<NamedDecl *>(Specifier));
141
142  return 0;
143}
144
145/// \brief Retrieve the namespace alias stored in this nested name
146/// specifier.
147NamespaceAliasDecl *NestedNameSpecifier::getAsNamespaceAlias() const {
148  if (Prefix.getInt() == StoredNamespaceOrAlias)
149    return dyn_cast<NamespaceAliasDecl>(static_cast<NamedDecl *>(Specifier));
150
151  return 0;
152}
153
154
155/// \brief Whether this nested name specifier refers to a dependent
156/// type or not.
157bool NestedNameSpecifier::isDependent() const {
158  switch (getKind()) {
159  case Identifier:
160    // Identifier specifiers always represent dependent types
161    return true;
162
163  case Namespace:
164  case NamespaceAlias:
165  case Global:
166    return false;
167
168  case TypeSpec:
169  case TypeSpecWithTemplate:
170    return getAsType()->isDependentType();
171  }
172
173  llvm_unreachable("Invalid NNS Kind!");
174}
175
176/// \brief Whether this nested name specifier refers to a dependent
177/// type or not.
178bool NestedNameSpecifier::isInstantiationDependent() const {
179  switch (getKind()) {
180  case Identifier:
181    // Identifier specifiers always represent dependent types
182    return true;
183
184  case Namespace:
185  case NamespaceAlias:
186  case Global:
187    return false;
188
189  case TypeSpec:
190  case TypeSpecWithTemplate:
191    return getAsType()->isInstantiationDependentType();
192  }
193
194  llvm_unreachable("Invalid NNS Kind!");
195}
196
197bool NestedNameSpecifier::containsUnexpandedParameterPack() const {
198  switch (getKind()) {
199  case Identifier:
200    return getPrefix() && getPrefix()->containsUnexpandedParameterPack();
201
202  case Namespace:
203  case NamespaceAlias:
204  case Global:
205    return false;
206
207  case TypeSpec:
208  case TypeSpecWithTemplate:
209    return getAsType()->containsUnexpandedParameterPack();
210  }
211
212  llvm_unreachable("Invalid NNS Kind!");
213}
214
215/// \brief Print this nested name specifier to the given output
216/// stream.
217void
218NestedNameSpecifier::print(raw_ostream &OS,
219                           const PrintingPolicy &Policy) const {
220  if (getPrefix())
221    getPrefix()->print(OS, Policy);
222
223  switch (getKind()) {
224  case Identifier:
225    OS << getAsIdentifier()->getName();
226    break;
227
228  case Namespace:
229    if (getAsNamespace()->isAnonymousNamespace())
230      return;
231
232    OS << getAsNamespace()->getName();
233    break;
234
235  case NamespaceAlias:
236    OS << getAsNamespaceAlias()->getName();
237    break;
238
239  case Global:
240    break;
241
242  case TypeSpecWithTemplate:
243    OS << "template ";
244    // Fall through to print the type.
245
246  case TypeSpec: {
247    std::string TypeStr;
248    const Type *T = getAsType();
249
250    PrintingPolicy InnerPolicy(Policy);
251    InnerPolicy.SuppressScope = true;
252
253    // Nested-name-specifiers are intended to contain minimally-qualified
254    // types. An actual ElaboratedType will not occur, since we'll store
255    // just the type that is referred to in the nested-name-specifier (e.g.,
256    // a TypedefType, TagType, etc.). However, when we are dealing with
257    // dependent template-id types (e.g., Outer<T>::template Inner<U>),
258    // the type requires its own nested-name-specifier for uniqueness, so we
259    // suppress that nested-name-specifier during printing.
260    assert(!isa<ElaboratedType>(T) &&
261           "Elaborated type in nested-name-specifier");
262    if (const TemplateSpecializationType *SpecType
263          = dyn_cast<TemplateSpecializationType>(T)) {
264      // Print the template name without its corresponding
265      // nested-name-specifier.
266      SpecType->getTemplateName().print(OS, InnerPolicy, true);
267
268      // Print the template argument list.
269      TypeStr = TemplateSpecializationType::PrintTemplateArgumentList(
270                                                          SpecType->getArgs(),
271                                                       SpecType->getNumArgs(),
272                                                                 InnerPolicy);
273    } else {
274      // Print the type normally
275      TypeStr = QualType(T, 0).getAsString(InnerPolicy);
276    }
277    OS << TypeStr;
278    break;
279  }
280  }
281
282  OS << "::";
283}
284
285void NestedNameSpecifier::dump(const LangOptions &LO) {
286  print(llvm::errs(), PrintingPolicy(LO));
287}
288
289unsigned
290NestedNameSpecifierLoc::getLocalDataLength(NestedNameSpecifier *Qualifier) {
291  assert(Qualifier && "Expected a non-NULL qualifier");
292
293  // Location of the trailing '::'.
294  unsigned Length = sizeof(unsigned);
295
296  switch (Qualifier->getKind()) {
297  case NestedNameSpecifier::Global:
298    // Nothing more to add.
299    break;
300
301  case NestedNameSpecifier::Identifier:
302  case NestedNameSpecifier::Namespace:
303  case NestedNameSpecifier::NamespaceAlias:
304    // The location of the identifier or namespace name.
305    Length += sizeof(unsigned);
306    break;
307
308  case NestedNameSpecifier::TypeSpecWithTemplate:
309  case NestedNameSpecifier::TypeSpec:
310    // The "void*" that points at the TypeLoc data.
311    // Note: the 'template' keyword is part of the TypeLoc.
312    Length += sizeof(void *);
313    break;
314  }
315
316  return Length;
317}
318
319unsigned
320NestedNameSpecifierLoc::getDataLength(NestedNameSpecifier *Qualifier) {
321  unsigned Length = 0;
322  for (; Qualifier; Qualifier = Qualifier->getPrefix())
323    Length += getLocalDataLength(Qualifier);
324  return Length;
325}
326
327namespace {
328  /// \brief Load a (possibly unaligned) source location from a given address
329  /// and offset.
330  SourceLocation LoadSourceLocation(void *Data, unsigned Offset) {
331    unsigned Raw;
332    memcpy(&Raw, static_cast<char *>(Data) + Offset, sizeof(unsigned));
333    return SourceLocation::getFromRawEncoding(Raw);
334  }
335
336  /// \brief Load a (possibly unaligned) pointer from a given address and
337  /// offset.
338  void *LoadPointer(void *Data, unsigned Offset) {
339    void *Result;
340    memcpy(&Result, static_cast<char *>(Data) + Offset, sizeof(void*));
341    return Result;
342  }
343}
344
345SourceRange NestedNameSpecifierLoc::getSourceRange() const {
346  if (!Qualifier)
347    return SourceRange();
348
349  NestedNameSpecifierLoc First = *this;
350  while (NestedNameSpecifierLoc Prefix = First.getPrefix())
351    First = Prefix;
352
353  return SourceRange(First.getLocalSourceRange().getBegin(),
354                     getLocalSourceRange().getEnd());
355}
356
357SourceRange NestedNameSpecifierLoc::getLocalSourceRange() const {
358  if (!Qualifier)
359    return SourceRange();
360
361  unsigned Offset = getDataLength(Qualifier->getPrefix());
362  switch (Qualifier->getKind()) {
363  case NestedNameSpecifier::Global:
364    return LoadSourceLocation(Data, Offset);
365
366  case NestedNameSpecifier::Identifier:
367  case NestedNameSpecifier::Namespace:
368  case NestedNameSpecifier::NamespaceAlias:
369    return SourceRange(LoadSourceLocation(Data, Offset),
370                       LoadSourceLocation(Data, Offset + sizeof(unsigned)));
371
372  case NestedNameSpecifier::TypeSpecWithTemplate:
373  case NestedNameSpecifier::TypeSpec: {
374    // The "void*" that points at the TypeLoc data.
375    // Note: the 'template' keyword is part of the TypeLoc.
376    void *TypeData = LoadPointer(Data, Offset);
377    TypeLoc TL(Qualifier->getAsType(), TypeData);
378    return SourceRange(TL.getBeginLoc(),
379                       LoadSourceLocation(Data, Offset + sizeof(void*)));
380  }
381  }
382
383  llvm_unreachable("Invalid NNS Kind!");
384}
385
386TypeLoc NestedNameSpecifierLoc::getTypeLoc() const {
387  assert((Qualifier->getKind() == NestedNameSpecifier::TypeSpec ||
388          Qualifier->getKind() == NestedNameSpecifier::TypeSpecWithTemplate) &&
389         "Nested-name-specifier location is not a type");
390
391  // The "void*" that points at the TypeLoc data.
392  unsigned Offset = getDataLength(Qualifier->getPrefix());
393  void *TypeData = LoadPointer(Data, Offset);
394  return TypeLoc(Qualifier->getAsType(), TypeData);
395}
396
397namespace {
398  void Append(char *Start, char *End, char *&Buffer, unsigned &BufferSize,
399              unsigned &BufferCapacity) {
400    if (BufferSize + (End - Start) > BufferCapacity) {
401      // Reallocate the buffer.
402      unsigned NewCapacity
403      = std::max((unsigned)(BufferCapacity? BufferCapacity * 2
404                            : sizeof(void*) * 2),
405                 (unsigned)(BufferSize + (End - Start)));
406      char *NewBuffer = static_cast<char *>(malloc(NewCapacity));
407      memcpy(NewBuffer, Buffer, BufferSize);
408
409      if (BufferCapacity)
410        free(Buffer);
411      Buffer = NewBuffer;
412      BufferCapacity = NewCapacity;
413    }
414
415    memcpy(Buffer + BufferSize, Start, End - Start);
416    BufferSize += End-Start;
417  }
418
419  /// \brief Save a source location to the given buffer.
420  void SaveSourceLocation(SourceLocation Loc, char *&Buffer,
421                          unsigned &BufferSize, unsigned &BufferCapacity) {
422    unsigned Raw = Loc.getRawEncoding();
423    Append(reinterpret_cast<char *>(&Raw),
424           reinterpret_cast<char *>(&Raw) + sizeof(unsigned),
425           Buffer, BufferSize, BufferCapacity);
426  }
427
428  /// \brief Save a pointer to the given buffer.
429  void SavePointer(void *Ptr, char *&Buffer, unsigned &BufferSize,
430                   unsigned &BufferCapacity) {
431    Append(reinterpret_cast<char *>(&Ptr),
432           reinterpret_cast<char *>(&Ptr) + sizeof(void *),
433           Buffer, BufferSize, BufferCapacity);
434  }
435}
436
437NestedNameSpecifierLocBuilder::
438NestedNameSpecifierLocBuilder(const NestedNameSpecifierLocBuilder &Other)
439  : Representation(Other.Representation), Buffer(0),
440    BufferSize(0), BufferCapacity(0)
441{
442  if (!Other.Buffer)
443    return;
444
445  if (Other.BufferCapacity == 0) {
446    // Shallow copy is okay.
447    Buffer = Other.Buffer;
448    BufferSize = Other.BufferSize;
449    return;
450  }
451
452  // Deep copy
453  BufferSize = Other.BufferSize;
454  BufferCapacity = Other.BufferSize;
455  Buffer = static_cast<char *>(malloc(BufferCapacity));
456  memcpy(Buffer, Other.Buffer, BufferSize);
457}
458
459NestedNameSpecifierLocBuilder &
460NestedNameSpecifierLocBuilder::
461operator=(const NestedNameSpecifierLocBuilder &Other) {
462  Representation = Other.Representation;
463
464  if (Buffer && Other.Buffer && BufferCapacity >= Other.BufferSize) {
465    // Re-use our storage.
466    BufferSize = Other.BufferSize;
467    memcpy(Buffer, Other.Buffer, BufferSize);
468    return *this;
469  }
470
471  // Free our storage, if we have any.
472  if (BufferCapacity) {
473    free(Buffer);
474    BufferCapacity = 0;
475  }
476
477  if (!Other.Buffer) {
478    // Empty.
479    Buffer = 0;
480    BufferSize = 0;
481    return *this;
482  }
483
484  if (Other.BufferCapacity == 0) {
485    // Shallow copy is okay.
486    Buffer = Other.Buffer;
487    BufferSize = Other.BufferSize;
488    return *this;
489  }
490
491  // Deep copy.
492  BufferSize = Other.BufferSize;
493  BufferCapacity = BufferSize;
494  Buffer = static_cast<char *>(malloc(BufferSize));
495  memcpy(Buffer, Other.Buffer, BufferSize);
496  return *this;
497}
498
499void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
500                                           SourceLocation TemplateKWLoc,
501                                           TypeLoc TL,
502                                           SourceLocation ColonColonLoc) {
503  Representation = NestedNameSpecifier::Create(Context, Representation,
504                                               TemplateKWLoc.isValid(),
505                                               TL.getTypePtr());
506
507  // Push source-location info into the buffer.
508  SavePointer(TL.getOpaqueData(), Buffer, BufferSize, BufferCapacity);
509  SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
510}
511
512void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
513                                           IdentifierInfo *Identifier,
514                                           SourceLocation IdentifierLoc,
515                                           SourceLocation ColonColonLoc) {
516  Representation = NestedNameSpecifier::Create(Context, Representation,
517                                               Identifier);
518
519  // Push source-location info into the buffer.
520  SaveSourceLocation(IdentifierLoc, Buffer, BufferSize, BufferCapacity);
521  SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
522}
523
524void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
525                                           NamespaceDecl *Namespace,
526                                           SourceLocation NamespaceLoc,
527                                           SourceLocation ColonColonLoc) {
528  Representation = NestedNameSpecifier::Create(Context, Representation,
529                                               Namespace);
530
531  // Push source-location info into the buffer.
532  SaveSourceLocation(NamespaceLoc, Buffer, BufferSize, BufferCapacity);
533  SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
534}
535
536void NestedNameSpecifierLocBuilder::Extend(ASTContext &Context,
537                                           NamespaceAliasDecl *Alias,
538                                           SourceLocation AliasLoc,
539                                           SourceLocation ColonColonLoc) {
540  Representation = NestedNameSpecifier::Create(Context, Representation, Alias);
541
542  // Push source-location info into the buffer.
543  SaveSourceLocation(AliasLoc, Buffer, BufferSize, BufferCapacity);
544  SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
545}
546
547void NestedNameSpecifierLocBuilder::MakeGlobal(ASTContext &Context,
548                                               SourceLocation ColonColonLoc) {
549  assert(!Representation && "Already have a nested-name-specifier!?");
550  Representation = NestedNameSpecifier::GlobalSpecifier(Context);
551
552  // Push source-location info into the buffer.
553  SaveSourceLocation(ColonColonLoc, Buffer, BufferSize, BufferCapacity);
554}
555
556void NestedNameSpecifierLocBuilder::MakeTrivial(ASTContext &Context,
557                                                NestedNameSpecifier *Qualifier,
558                                                SourceRange R) {
559  Representation = Qualifier;
560
561  // Construct bogus (but well-formed) source information for the
562  // nested-name-specifier.
563  BufferSize = 0;
564  SmallVector<NestedNameSpecifier *, 4> Stack;
565  for (NestedNameSpecifier *NNS = Qualifier; NNS; NNS = NNS->getPrefix())
566    Stack.push_back(NNS);
567  while (!Stack.empty()) {
568    NestedNameSpecifier *NNS = Stack.back();
569    Stack.pop_back();
570    switch (NNS->getKind()) {
571      case NestedNameSpecifier::Identifier:
572      case NestedNameSpecifier::Namespace:
573      case NestedNameSpecifier::NamespaceAlias:
574        SaveSourceLocation(R.getBegin(), Buffer, BufferSize, BufferCapacity);
575        break;
576
577      case NestedNameSpecifier::TypeSpec:
578      case NestedNameSpecifier::TypeSpecWithTemplate: {
579        TypeSourceInfo *TSInfo
580        = Context.getTrivialTypeSourceInfo(QualType(NNS->getAsType(), 0),
581                                           R.getBegin());
582        SavePointer(TSInfo->getTypeLoc().getOpaqueData(), Buffer, BufferSize,
583                    BufferCapacity);
584        break;
585      }
586
587      case NestedNameSpecifier::Global:
588        break;
589    }
590
591    // Save the location of the '::'.
592    SaveSourceLocation(Stack.empty()? R.getEnd() : R.getBegin(),
593                       Buffer, BufferSize, BufferCapacity);
594  }
595}
596
597void NestedNameSpecifierLocBuilder::Adopt(NestedNameSpecifierLoc Other) {
598  if (BufferCapacity)
599    free(Buffer);
600
601  if (!Other) {
602    Representation = 0;
603    BufferSize = 0;
604    return;
605  }
606
607  // Rather than copying the data (which is wasteful), "adopt" the
608  // pointer (which points into the ASTContext) but set the capacity to zero to
609  // indicate that we don't own it.
610  Representation = Other.getNestedNameSpecifier();
611  Buffer = static_cast<char *>(Other.getOpaqueData());
612  BufferSize = Other.getDataLength();
613  BufferCapacity = 0;
614}
615
616NestedNameSpecifierLoc
617NestedNameSpecifierLocBuilder::getWithLocInContext(ASTContext &Context) const {
618  if (!Representation)
619    return NestedNameSpecifierLoc();
620
621  // If we adopted our data pointer from elsewhere in the AST context, there's
622  // no need to copy the memory.
623  if (BufferCapacity == 0)
624    return NestedNameSpecifierLoc(Representation, Buffer);
625
626  // FIXME: After copying the source-location information, should we free
627  // our (temporary) buffer and adopt the ASTContext-allocated memory?
628  // Doing so would optimize repeated calls to getWithLocInContext().
629  void *Mem = Context.Allocate(BufferSize, llvm::alignOf<void *>());
630  memcpy(Mem, Buffer, BufferSize);
631  return NestedNameSpecifierLoc(Representation, Mem);
632}
633
634