1 //===--- Scope.h - Scope interface ------------------------------*- 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 Scope interface. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_CLANG_SEMA_SCOPE_H 15 #define LLVM_CLANG_SEMA_SCOPE_H 16 17 #include "clang/Basic/Diagnostic.h" 18 #include "llvm/ADT/SmallPtrSet.h" 19 #include "llvm/ADT/SmallVector.h" 20 21 namespace clang { 22 23 class Decl; 24 class UsingDirectiveDecl; 25 26 /// Scope - A scope is a transient data structure that is used while parsing the 27 /// program. It assists with resolving identifiers to the appropriate 28 /// declaration. 29 /// 30 class Scope { 31 public: 32 /// ScopeFlags - These are bitfields that are or'd together when creating a 33 /// scope, which defines the sorts of things the scope contains. 34 enum ScopeFlags { 35 /// \brief This indicates that the scope corresponds to a function, which 36 /// means that labels are set here. 37 FnScope = 0x01, 38 39 /// \brief This is a while, do, switch, for, etc that can have break 40 /// statements embedded into it. 41 BreakScope = 0x02, 42 43 /// \brief This is a while, do, for, which can have continue statements 44 /// embedded into it. 45 ContinueScope = 0x04, 46 47 /// \brief This is a scope that can contain a declaration. Some scopes 48 /// just contain loop constructs but don't contain decls. 49 DeclScope = 0x08, 50 51 /// \brief The controlling scope in a if/switch/while/for statement. 52 ControlScope = 0x10, 53 54 /// \brief The scope of a struct/union/class definition. 55 ClassScope = 0x20, 56 57 /// \brief This is a scope that corresponds to a block/closure object. 58 /// Blocks serve as top-level scopes for some objects like labels, they 59 /// also prevent things like break and continue. BlockScopes always have 60 /// the FnScope and DeclScope flags set as well. 61 BlockScope = 0x40, 62 63 /// \brief This is a scope that corresponds to the 64 /// template parameters of a C++ template. Template parameter 65 /// scope starts at the 'template' keyword and ends when the 66 /// template declaration ends. 67 TemplateParamScope = 0x80, 68 69 /// \brief This is a scope that corresponds to the 70 /// parameters within a function prototype. 71 FunctionPrototypeScope = 0x100, 72 73 /// \brief This is a scope that corresponds to the parameters within 74 /// a function prototype for a function declaration (as opposed to any 75 /// other kind of function declarator). Always has FunctionPrototypeScope 76 /// set as well. 77 FunctionDeclarationScope = 0x200, 78 79 /// \brief This is a scope that corresponds to the Objective-C 80 /// \@catch statement. 81 AtCatchScope = 0x400, 82 83 /// \brief This scope corresponds to an Objective-C method body. 84 /// It always has FnScope and DeclScope set as well. 85 ObjCMethodScope = 0x800, 86 87 /// \brief This is a scope that corresponds to a switch statement. 88 SwitchScope = 0x1000, 89 90 /// \brief This is the scope of a C++ try statement. 91 TryScope = 0x2000, 92 93 /// \brief This is the scope for a function-level C++ try or catch scope. 94 FnTryCatchScope = 0x4000 95 }; 96 private: 97 /// The parent scope for this scope. This is null for the translation-unit 98 /// scope. 99 Scope *AnyParent; 100 101 /// Depth - This is the depth of this scope. The translation-unit scope has 102 /// depth 0. 103 unsigned short Depth; 104 105 /// Flags - This contains a set of ScopeFlags, which indicates how the scope 106 /// interrelates with other control flow statements. 107 unsigned short Flags; 108 109 /// PrototypeDepth - This is the number of function prototype scopes 110 /// enclosing this scope, including this scope. 111 unsigned short PrototypeDepth; 112 113 /// PrototypeIndex - This is the number of parameters currently 114 /// declared in this scope. 115 unsigned short PrototypeIndex; 116 117 /// FnParent - If this scope has a parent scope that is a function body, this 118 /// pointer is non-null and points to it. This is used for label processing. 119 Scope *FnParent; 120 121 /// BreakParent/ContinueParent - This is a direct link to the innermost 122 /// BreakScope/ContinueScope which contains the contents of this scope 123 /// for control flow purposes (and might be this scope itself), or null 124 /// if there is no such scope. 125 Scope *BreakParent, *ContinueParent; 126 127 /// BlockParent - This is a direct link to the immediately containing 128 /// BlockScope if this scope is not one, or null if there is none. 129 Scope *BlockParent; 130 131 /// TemplateParamParent - This is a direct link to the 132 /// immediately containing template parameter scope. In the 133 /// case of nested templates, template parameter scopes can have 134 /// other template parameter scopes as parents. 135 Scope *TemplateParamParent; 136 137 /// DeclsInScope - This keeps track of all declarations in this scope. When 138 /// the declaration is added to the scope, it is set as the current 139 /// declaration for the identifier in the IdentifierTable. When the scope is 140 /// popped, these declarations are removed from the IdentifierTable's notion 141 /// of current declaration. It is up to the current Action implementation to 142 /// implement these semantics. 143 typedef llvm::SmallPtrSet<Decl *, 32> DeclSetTy; 144 DeclSetTy DeclsInScope; 145 146 /// Entity - The entity with which this scope is associated. For 147 /// example, the entity of a class scope is the class itself, the 148 /// entity of a function scope is a function, etc. This field is 149 /// maintained by the Action implementation. 150 void *Entity; 151 152 typedef SmallVector<UsingDirectiveDecl *, 2> UsingDirectivesTy; 153 UsingDirectivesTy UsingDirectives; 154 155 /// \brief Used to determine if errors occurred in this scope. 156 DiagnosticErrorTrap ErrorTrap; 157 158 public: 159 Scope(Scope *Parent, unsigned ScopeFlags, DiagnosticsEngine &Diag) 160 : ErrorTrap(Diag) { 161 Init(Parent, ScopeFlags); 162 } 163 164 /// getFlags - Return the flags for this scope. 165 /// 166 unsigned getFlags() const { return Flags; } 167 void setFlags(unsigned F) { Flags = F; } 168 169 /// isBlockScope - Return true if this scope correspond to a closure. 170 bool isBlockScope() const { return Flags & BlockScope; } 171 172 /// getParent - Return the scope that this is nested in. 173 /// 174 const Scope *getParent() const { return AnyParent; } 175 Scope *getParent() { return AnyParent; } 176 177 /// getFnParent - Return the closest scope that is a function body. 178 /// 179 const Scope *getFnParent() const { return FnParent; } 180 Scope *getFnParent() { return FnParent; } 181 182 /// getContinueParent - Return the closest scope that a continue statement 183 /// would be affected by. 184 Scope *getContinueParent() { 185 return ContinueParent; 186 } 187 188 const Scope *getContinueParent() const { 189 return const_cast<Scope*>(this)->getContinueParent(); 190 } 191 192 /// getBreakParent - Return the closest scope that a break statement 193 /// would be affected by. 194 Scope *getBreakParent() { 195 return BreakParent; 196 } 197 const Scope *getBreakParent() const { 198 return const_cast<Scope*>(this)->getBreakParent(); 199 } 200 201 Scope *getBlockParent() { return BlockParent; } 202 const Scope *getBlockParent() const { return BlockParent; } 203 204 Scope *getTemplateParamParent() { return TemplateParamParent; } 205 const Scope *getTemplateParamParent() const { return TemplateParamParent; } 206 207 /// Returns the number of function prototype scopes in this scope 208 /// chain. 209 unsigned getFunctionPrototypeDepth() const { 210 return PrototypeDepth; 211 } 212 213 /// Return the number of parameters declared in this function 214 /// prototype, increasing it by one for the next call. 215 unsigned getNextFunctionPrototypeIndex() { 216 assert(isFunctionPrototypeScope()); 217 return PrototypeIndex++; 218 } 219 220 typedef DeclSetTy::iterator decl_iterator; 221 decl_iterator decl_begin() const { return DeclsInScope.begin(); } 222 decl_iterator decl_end() const { return DeclsInScope.end(); } 223 bool decl_empty() const { return DeclsInScope.empty(); } 224 225 void AddDecl(Decl *D) { 226 DeclsInScope.insert(D); 227 } 228 229 void RemoveDecl(Decl *D) { 230 DeclsInScope.erase(D); 231 } 232 233 /// isDeclScope - Return true if this is the scope that the specified decl is 234 /// declared in. 235 bool isDeclScope(Decl *D) { 236 return DeclsInScope.count(D) != 0; 237 } 238 239 void* getEntity() const { return Entity; } 240 void setEntity(void *E) { Entity = E; } 241 242 bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); } 243 244 /// isClassScope - Return true if this scope is a class/struct/union scope. 245 bool isClassScope() const { 246 return (getFlags() & Scope::ClassScope); 247 } 248 249 /// isInCXXInlineMethodScope - Return true if this scope is a C++ inline 250 /// method scope or is inside one. 251 bool isInCXXInlineMethodScope() const { 252 if (const Scope *FnS = getFnParent()) { 253 assert(FnS->getParent() && "TUScope not created?"); 254 return FnS->getParent()->isClassScope(); 255 } 256 return false; 257 } 258 259 /// isInObjcMethodScope - Return true if this scope is, or is contained in, an 260 /// Objective-C method body. Note that this method is not constant time. 261 bool isInObjcMethodScope() const { 262 for (const Scope *S = this; S; S = S->getParent()) { 263 // If this scope is an objc method scope, then we succeed. 264 if (S->getFlags() & ObjCMethodScope) 265 return true; 266 } 267 return false; 268 } 269 270 /// isTemplateParamScope - Return true if this scope is a C++ 271 /// template parameter scope. 272 bool isTemplateParamScope() const { 273 return getFlags() & Scope::TemplateParamScope; 274 } 275 276 /// isFunctionPrototypeScope - Return true if this scope is a 277 /// function prototype scope. 278 bool isFunctionPrototypeScope() const { 279 return getFlags() & Scope::FunctionPrototypeScope; 280 } 281 282 /// isAtCatchScope - Return true if this scope is \@catch. 283 bool isAtCatchScope() const { 284 return getFlags() & Scope::AtCatchScope; 285 } 286 287 /// isSwitchScope - Return true if this scope is a switch scope. 288 bool isSwitchScope() const { 289 for (const Scope *S = this; S; S = S->getParent()) { 290 if (S->getFlags() & Scope::SwitchScope) 291 return true; 292 else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope | 293 Scope::BlockScope | Scope::TemplateParamScope | 294 Scope::FunctionPrototypeScope | 295 Scope::AtCatchScope | Scope::ObjCMethodScope)) 296 return false; 297 } 298 return false; 299 } 300 301 /// \brief Determine whether this scope is a C++ 'try' block. 302 bool isTryScope() const { return getFlags() & Scope::TryScope; } 303 304 /// containedInPrototypeScope - Return true if this or a parent scope 305 /// is a FunctionPrototypeScope. 306 bool containedInPrototypeScope() const; 307 308 typedef UsingDirectivesTy::iterator udir_iterator; 309 typedef UsingDirectivesTy::const_iterator const_udir_iterator; 310 311 void PushUsingDirective(UsingDirectiveDecl *UDir) { 312 UsingDirectives.push_back(UDir); 313 } 314 315 udir_iterator using_directives_begin() { 316 return UsingDirectives.begin(); 317 } 318 319 udir_iterator using_directives_end() { 320 return UsingDirectives.end(); 321 } 322 323 const_udir_iterator using_directives_begin() const { 324 return UsingDirectives.begin(); 325 } 326 327 const_udir_iterator using_directives_end() const { 328 return UsingDirectives.end(); 329 } 330 331 /// Init - This is used by the parser to implement scope caching. 332 /// 333 void Init(Scope *parent, unsigned flags); 334 }; 335 336 } // end namespace clang 337 338 #endif 339
