IdentifierResolver.cpp revision f4bae14c1c2cb086d42aecf84c6779787c6c7d89 
1//===- IdentifierResolver.cpp - Lexical Scope Name lookup -------*- 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 implements the IdentifierResolver class, which is used for lexical
11// scoped lookup, based on declaration names.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Sema/IdentifierResolver.h"
16#include "clang/Basic/LangOptions.h"
17
18using namespace clang;
19
20//===----------------------------------------------------------------------===//
21// IdDeclInfoMap class
22//===----------------------------------------------------------------------===//
23
24/// IdDeclInfoMap - Associates IdDeclInfos with declaration names.
25/// Allocates 'pools' (vectors of IdDeclInfos) to avoid allocating each
26/// individual IdDeclInfo to heap.
27class IdentifierResolver::IdDeclInfoMap {
28  static const unsigned int POOL_SIZE = 512;
29
30  /// We use our own linked-list implementation because it is sadly
31  /// impossible to add something to a pre-C++0x STL container without
32  /// a completely unnecessary copy.
33  struct IdDeclInfoPool {
34    IdDeclInfoPool(IdDeclInfoPool *Next) : Next(Next) {}
35
36    IdDeclInfoPool *Next;
37    IdDeclInfo Pool[POOL_SIZE];
38  };
39
40  IdDeclInfoPool *CurPool;
41  unsigned int CurIndex;
42
43public:
44  IdDeclInfoMap() : CurPool(0), CurIndex(POOL_SIZE) {}
45
46  ~IdDeclInfoMap() {
47    IdDeclInfoPool *Cur = CurPool;
48    while (IdDeclInfoPool *P = Cur) {
49      Cur = Cur->Next;
50      delete P;
51    }
52  }
53
54  /// Returns the IdDeclInfo associated to the DeclarationName.
55  /// It creates a new IdDeclInfo if one was not created before for this id.
56  IdDeclInfo &operator[](DeclarationName Name);
57};
58
59
60//===----------------------------------------------------------------------===//
61// IdDeclInfo Implementation
62//===----------------------------------------------------------------------===//
63
64/// RemoveDecl - Remove the decl from the scope chain.
65/// The decl must already be part of the decl chain.
66void IdentifierResolver::IdDeclInfo::RemoveDecl(NamedDecl *D) {
67  for (DeclsTy::iterator I = Decls.end(); I != Decls.begin(); --I) {
68    if (D == *(I-1)) {
69      Decls.erase(I-1);
70      return;
71    }
72  }
73
74  assert(0 && "Didn't find this decl on its identifier's chain!");
75}
76
77bool
78IdentifierResolver::IdDeclInfo::ReplaceDecl(NamedDecl *Old, NamedDecl *New) {
79  for (DeclsTy::iterator I = Decls.end(); I != Decls.begin(); --I) {
80    if (Old == *(I-1)) {
81      *(I - 1) = New;
82      return true;
83    }
84  }
85
86  return false;
87}
88
89
90//===----------------------------------------------------------------------===//
91// IdentifierResolver Implementation
92//===----------------------------------------------------------------------===//
93
94IdentifierResolver::IdentifierResolver(const LangOptions &langOpt)
95    : LangOpt(langOpt), IdDeclInfos(new IdDeclInfoMap) {
96}
97IdentifierResolver::~IdentifierResolver() {
98  delete IdDeclInfos;
99}
100
101/// isDeclInScope - If 'Ctx' is a function/method, isDeclInScope returns true
102/// if 'D' is in Scope 'S', otherwise 'S' is ignored and isDeclInScope returns
103/// true if 'D' belongs to the given declaration context.
104bool IdentifierResolver::isDeclInScope(Decl *D, DeclContext *Ctx,
105                                       ASTContext &Context, Scope *S) const {
106  Ctx = Ctx->getLookupContext();
107
108  if (Ctx->isFunctionOrMethod()) {
109    // Ignore the scopes associated within transparent declaration contexts.
110    while (S->getEntity() &&
111           ((DeclContext *)S->getEntity())->isTransparentContext())
112      S = S->getParent();
113
114    if (S->isDeclScope(D))
115      return true;
116    if (LangOpt.CPlusPlus) {
117      // C++ 3.3.2p3:
118      // The name declared in a catch exception-declaration is local to the
119      // handler and shall not be redeclared in the outermost block of the
120      // handler.
121      // C++ 3.3.2p4:
122      // Names declared in the for-init-statement, and in the condition of if,
123      // while, for, and switch statements are local to the if, while, for, or
124      // switch statement (including the controlled statement), and shall not be
125      // redeclared in a subsequent condition of that statement nor in the
126      // outermost block (or, for the if statement, any of the outermost blocks)
127      // of the controlled statement.
128      //
129      assert(S->getParent() && "No TUScope?");
130      if (S->getParent()->getFlags() & Scope::ControlScope)
131        return S->getParent()->isDeclScope(D);
132    }
133    return false;
134  }
135
136  return D->getDeclContext()->getLookupContext()->Equals(Ctx);
137}
138
139/// AddDecl - Link the decl to its shadowed decl chain.
140void IdentifierResolver::AddDecl(NamedDecl *D) {
141  DeclarationName Name = D->getDeclName();
142  if (IdentifierInfo *II = Name.getAsIdentifierInfo())
143    II->setIsFromAST(false);
144
145  void *Ptr = Name.getFETokenInfo<void>();
146
147  if (!Ptr) {
148    Name.setFETokenInfo(D);
149    return;
150  }
151
152  IdDeclInfo *IDI;
153
154  if (isDeclPtr(Ptr)) {
155    Name.setFETokenInfo(NULL);
156    IDI = &(*IdDeclInfos)[Name];
157    NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr);
158    IDI->AddDecl(PrevD);
159  } else
160    IDI = toIdDeclInfo(Ptr);
161
162  IDI->AddDecl(D);
163}
164
165/// RemoveDecl - Unlink the decl from its shadowed decl chain.
166/// The decl must already be part of the decl chain.
167void IdentifierResolver::RemoveDecl(NamedDecl *D) {
168  assert(D && "null param passed");
169  DeclarationName Name = D->getDeclName();
170  if (IdentifierInfo *II = Name.getAsIdentifierInfo())
171    II->setIsFromAST(false);
172
173  void *Ptr = Name.getFETokenInfo<void>();
174
175  assert(Ptr && "Didn't find this decl on its identifier's chain!");
176
177  if (isDeclPtr(Ptr)) {
178    assert(D == Ptr && "Didn't find this decl on its identifier's chain!");
179    Name.setFETokenInfo(NULL);
180    return;
181  }
182
183  return toIdDeclInfo(Ptr)->RemoveDecl(D);
184}
185
186bool IdentifierResolver::ReplaceDecl(NamedDecl *Old, NamedDecl *New) {
187  assert(Old->getDeclName() == New->getDeclName() &&
188         "Cannot replace a decl with another decl of a different name");
189
190  DeclarationName Name = Old->getDeclName();
191  if (IdentifierInfo *II = Name.getAsIdentifierInfo())
192    II->setIsFromAST(false);
193
194  void *Ptr = Name.getFETokenInfo<void>();
195
196  if (!Ptr)
197    return false;
198
199  if (isDeclPtr(Ptr)) {
200    if (Ptr == Old) {
201      Name.setFETokenInfo(New);
202      return true;
203    }
204    return false;
205  }
206
207  return toIdDeclInfo(Ptr)->ReplaceDecl(Old, New);
208}
209
210/// begin - Returns an iterator for decls with name 'Name'.
211IdentifierResolver::iterator
212IdentifierResolver::begin(DeclarationName Name) {
213  void *Ptr = Name.getFETokenInfo<void>();
214  if (!Ptr) return end();
215
216  if (isDeclPtr(Ptr))
217    return iterator(static_cast<NamedDecl*>(Ptr));
218
219  IdDeclInfo *IDI = toIdDeclInfo(Ptr);
220
221  IdDeclInfo::DeclsTy::iterator I = IDI->decls_end();
222  if (I != IDI->decls_begin())
223    return iterator(I-1);
224  // No decls found.
225  return end();
226}
227
228void IdentifierResolver::AddDeclToIdentifierChain(IdentifierInfo *II,
229                                                  NamedDecl *D) {
230  II->setIsFromAST(false);
231  void *Ptr = II->getFETokenInfo<void>();
232
233  if (!Ptr) {
234    II->setFETokenInfo(D);
235    return;
236  }
237
238  IdDeclInfo *IDI;
239
240  if (isDeclPtr(Ptr)) {
241    II->setFETokenInfo(NULL);
242    IDI = &(*IdDeclInfos)[II];
243    NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr);
244    IDI->AddDecl(PrevD);
245  } else
246    IDI = toIdDeclInfo(Ptr);
247
248  IDI->AddDecl(D);
249}
250
251//===----------------------------------------------------------------------===//
252// IdDeclInfoMap Implementation
253//===----------------------------------------------------------------------===//
254
255/// Returns the IdDeclInfo associated to the DeclarationName.
256/// It creates a new IdDeclInfo if one was not created before for this id.
257IdentifierResolver::IdDeclInfo &
258IdentifierResolver::IdDeclInfoMap::operator[](DeclarationName Name) {
259  void *Ptr = Name.getFETokenInfo<void>();
260
261  if (Ptr) return *toIdDeclInfo(Ptr);
262
263  if (CurIndex == POOL_SIZE) {
264    CurPool = new IdDeclInfoPool(CurPool);
265    CurIndex = 0;
266  }
267  IdDeclInfo *IDI = &CurPool->Pool[CurIndex];
268  Name.setFETokenInfo(reinterpret_cast<void*>(
269                              reinterpret_cast<uintptr_t>(IDI) | 0x1)
270                                                                     );
271  ++CurIndex;
272  return *IDI;
273}
274