lib/Sema/IdentifierResolver.cpp

   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/Sema/Scope.h"
  17 #include "clang/AST/Decl.h"
  18 #include "clang/Basic/LangOptions.h"
  19
  20 using namespace clang;
  21
  22 //===----------------------------------------------------------------------===//
  23 // IdDeclInfoMap class
  24 //===----------------------------------------------------------------------===//
  25
  26 /// IdDeclInfoMap - Associates IdDeclInfos with declaration names.
  27 /// Allocates 'pools' (vectors of IdDeclInfos) to avoid allocating each
  28 /// individual IdDeclInfo to heap.
  29 class IdentifierResolver::IdDeclInfoMap {
  30   static const unsigned int POOL_SIZE = 512;
  31
  32   /// We use our own linked-list implementation because it is sadly
  33   /// impossible to add something to a pre-C++0x STL container without
  34   /// a completely unnecessary copy.
  35   struct IdDeclInfoPool {
  36     IdDeclInfoPool(IdDeclInfoPool *Next) : Next(Next) {}
  37
  38     IdDeclInfoPool *Next;
  39     IdDeclInfo Pool[POOL_SIZE];
  40   };
  41
  42   IdDeclInfoPool *CurPool;
  43   unsigned int CurIndex;
  44
  45 public:
  46   IdDeclInfoMap() : CurPool(0), CurIndex(POOL_SIZE) {}
  47
  48   ~IdDeclInfoMap() {
  49     IdDeclInfoPool *Cur = CurPool;
  50     while (IdDeclInfoPool *P = Cur) {
  51       Cur = Cur->Next;
  52       delete P;
  53     }
  54   }
  55
  56   /// Returns the IdDeclInfo associated to the DeclarationName.
  57   /// It creates a new IdDeclInfo if one was not created before for this id.
  58   IdDeclInfo &operator[](DeclarationName Name);
  59 };
  60
  61
  62 //===----------------------------------------------------------------------===//
  63 // IdDeclInfo Implementation
  64 //===----------------------------------------------------------------------===//
  65
  66 /// RemoveDecl - Remove the decl from the scope chain.
  67 /// The decl must already be part of the decl chain.
  68 void IdentifierResolver::IdDeclInfo::RemoveDecl(NamedDecl *D) {
  69   for (DeclsTy::iterator I = Decls.end(); I != Decls.begin(); --I) {
  70     if (D == *(I-1)) {
  71       Decls.erase(I-1);
  72       return;
  73     }
  74   }
  75
  76   assert(0 && "Didn't find this decl on its identifier's chain!");
  77 }
  78
  79 bool
  80 IdentifierResolver::IdDeclInfo::ReplaceDecl(NamedDecl *Old, NamedDecl *New) {
  81   for (DeclsTy::iterator I = Decls.end(); I != Decls.begin(); --I) {
  82     if (Old == *(I-1)) {
  83       *(I - 1) = New;
  84       return true;
  85     }
  86   }
  87
  88   return false;
  89 }
  90
  91
  92 //===----------------------------------------------------------------------===//
  93 // IdentifierResolver Implementation
  94 //===----------------------------------------------------------------------===//
  95
  96 IdentifierResolver::IdentifierResolver(const LangOptions &langOpt)
  97     : LangOpt(langOpt), IdDeclInfos(new IdDeclInfoMap) {
  98 }
  99 IdentifierResolver::~IdentifierResolver() {
 100   delete IdDeclInfos;
 101 }
 102
 103 /// isDeclInScope - If 'Ctx' is a function/method, isDeclInScope returns true
 104 /// if 'D' is in Scope 'S', otherwise 'S' is ignored and isDeclInScope returns
 105 /// true if 'D' belongs to the given declaration context.
 106 bool IdentifierResolver::isDeclInScope(Decl *D, DeclContext *Ctx,
 107                                        ASTContext &Context, Scope *S) const {
 108   Ctx = Ctx->getRedeclContext();
 109
 110   if (Ctx->isFunctionOrMethod()) {
 111     // Ignore the scopes associated within transparent declaration contexts.
 112     while (S->getEntity() &&
 113            ((DeclContext *)S->getEntity())->isTransparentContext())
 114       S = S->getParent();
 115
 116     if (S->isDeclScope(D))
 117       return true;
 118     if (LangOpt.CPlusPlus) {
 119       // C++ 3.3.2p3:
 120       // The name declared in a catch exception-declaration is local to the
 121       // handler and shall not be redeclared in the outermost block of the
 122       // handler.
 123       // C++ 3.3.2p4:
 124       // Names declared in the for-init-statement, and in the condition of if,
 125       // while, for, and switch statements are local to the if, while, for, or
 126       // switch statement (including the controlled statement), and shall not be
 127       // redeclared in a subsequent condition of that statement nor in the
 128       // outermost block (or, for the if statement, any of the outermost blocks)
 129       // of the controlled statement.
 130       //
 131       assert(S->getParent() && "No TUScope?");
 132       if (S->getParent()->getFlags() & Scope::ControlScope)
 133         return S->getParent()->isDeclScope(D);
 134     }
 135     return false;
 136   }
 137
 138   return D->getDeclContext()->getRedeclContext()->Equals(Ctx);
 139 }
 140
 141 /// AddDecl - Link the decl to its shadowed decl chain.
 142 void IdentifierResolver::AddDecl(NamedDecl *D) {
 143   DeclarationName Name = D->getDeclName();
 144   if (IdentifierInfo *II = Name.getAsIdentifierInfo())
 145     II->setIsFromAST(false);
 146
 147   void *Ptr = Name.getFETokenInfo<void>();
 148
 149   if (!Ptr) {
 150     Name.setFETokenInfo(D);
 151     return;
 152   }
 153
 154   IdDeclInfo *IDI;
 155
 156   if (isDeclPtr(Ptr)) {
 157     Name.setFETokenInfo(NULL);
 158     IDI = &(*IdDeclInfos)[Name];
 159     NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr);
 160     IDI->AddDecl(PrevD);
 161   } else
 162     IDI = toIdDeclInfo(Ptr);
 163
 164   IDI->AddDecl(D);
 165 }
 166
 167 /// RemoveDecl - Unlink the decl from its shadowed decl chain.
 168 /// The decl must already be part of the decl chain.
 169 void IdentifierResolver::RemoveDecl(NamedDecl *D) {
 170   assert(D && "null param passed");
 171   DeclarationName Name = D->getDeclName();
 172   if (IdentifierInfo *II = Name.getAsIdentifierInfo())
 173     II->setIsFromAST(false);
 174
 175   void *Ptr = Name.getFETokenInfo<void>();
 176
 177   assert(Ptr && "Didn't find this decl on its identifier's chain!");
 178
 179   if (isDeclPtr(Ptr)) {
 180     assert(D == Ptr && "Didn't find this decl on its identifier's chain!");
 181     Name.setFETokenInfo(NULL);
 182     return;
 183   }
 184
 185   return toIdDeclInfo(Ptr)->RemoveDecl(D);
 186 }
 187
 188 bool IdentifierResolver::ReplaceDecl(NamedDecl *Old, NamedDecl *New) {
 189   assert(Old->getDeclName() == New->getDeclName() &&
 190          "Cannot replace a decl with another decl of a different name");
 191
 192   DeclarationName Name = Old->getDeclName();
 193   if (IdentifierInfo *II = Name.getAsIdentifierInfo())
 194     II->setIsFromAST(false);
 195
 196   void *Ptr = Name.getFETokenInfo<void>();
 197
 198   if (!Ptr)
 199     return false;
 200
 201   if (isDeclPtr(Ptr)) {
 202     if (Ptr == Old) {
 203       Name.setFETokenInfo(New);
 204       return true;
 205     }
 206     return false;
 207   }
 208
 209   return toIdDeclInfo(Ptr)->ReplaceDecl(Old, New);
 210 }
 211
 212 /// begin - Returns an iterator for decls with name 'Name'.
 213 IdentifierResolver::iterator
 214 IdentifierResolver::begin(DeclarationName Name) {
 215   void *Ptr = Name.getFETokenInfo<void>();
 216   if (!Ptr) return end();
 217
 218   if (isDeclPtr(Ptr))
 219     return iterator(static_cast<NamedDecl*>(Ptr));
 220
 221   IdDeclInfo *IDI = toIdDeclInfo(Ptr);
 222
 223   IdDeclInfo::DeclsTy::iterator I = IDI->decls_end();
 224   if (I != IDI->decls_begin())
 225     return iterator(I-1);
 226   // No decls found.
 227   return end();
 228 }
 229
 230 void IdentifierResolver::AddDeclToIdentifierChain(IdentifierInfo *II,
 231                                                   NamedDecl *D) {
 232   II->setIsFromAST(false);
 233   void *Ptr = II->getFETokenInfo<void>();
 234
 235   if (!Ptr) {
 236     II->setFETokenInfo(D);
 237     return;
 238   }
 239
 240   IdDeclInfo *IDI;
 241
 242   if (isDeclPtr(Ptr)) {
 243     II->setFETokenInfo(NULL);
 244     IDI = &(*IdDeclInfos)[II];
 245     NamedDecl *PrevD = static_cast<NamedDecl*>(Ptr);
 246     IDI->AddDecl(PrevD);
 247   } else
 248     IDI = toIdDeclInfo(Ptr);
 249
 250   IDI->AddDecl(D);
 251 }
 252
 253 //===----------------------------------------------------------------------===//
 254 // IdDeclInfoMap Implementation
 255 //===----------------------------------------------------------------------===//
 256
 257 /// Returns the IdDeclInfo associated to the DeclarationName.
 258 /// It creates a new IdDeclInfo if one was not created before for this id.
 259 IdentifierResolver::IdDeclInfo &
 260 IdentifierResolver::IdDeclInfoMap::operator[](DeclarationName Name) {
 261   void *Ptr = Name.getFETokenInfo<void>();
 262
 263   if (Ptr) return *toIdDeclInfo(Ptr);
 264
 265   if (CurIndex == POOL_SIZE) {
 266     CurPool = new IdDeclInfoPool(CurPool);
 267     CurIndex = 0;
 268   }
 269   IdDeclInfo *IDI = &CurPool->Pool[CurIndex];
 270   Name.setFETokenInfo(reinterpret_cast<void*>(
 271                               reinterpret_cast<uintptr_t>(IDI) | 0x1)
 272                                                                      );
 273   ++CurIndex;
 274   return *IDI;
 275 }
 276
 277 void IdentifierResolver::iterator::incrementSlowCase() {
 278   NamedDecl *D = **this;
 279   void *InfoPtr = D->getDeclName().getFETokenInfo<void>();
 280   assert(!isDeclPtr(InfoPtr) && "Decl with wrong id ?");
 281   IdDeclInfo *Info = toIdDeclInfo(InfoPtr);
 282
 283   BaseIter I = getIterator();
 284   if (I != Info->decls_begin())
 285     *this = iterator(I-1);
 286   else // No more decls.
 287     *this = iterator();
 288 }