Scope.h revision 6bcf27bb9a4b5c3f79cb44c0e4654a6d7619ad89
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/PointerIntPair.h" 19#include "llvm/ADT/SmallPtrSet.h" 20#include "llvm/ADT/SmallVector.h" 21 22namespace llvm { 23 24class raw_ostream; 25 26} 27 28namespace clang { 29 30class Decl; 31class UsingDirectiveDecl; 32class VarDecl; 33 34/// Scope - A scope is a transient data structure that is used while parsing the 35/// program. It assists with resolving identifiers to the appropriate 36/// declaration. 37/// 38class Scope { 39public: 40 /// ScopeFlags - These are bitfields that are or'd together when creating a 41 /// scope, which defines the sorts of things the scope contains. 42 enum ScopeFlags { 43 /// \brief This indicates that the scope corresponds to a function, which 44 /// means that labels are set here. 45 FnScope = 0x01, 46 47 /// \brief This is a while, do, switch, for, etc that can have break 48 /// statements embedded into it. 49 BreakScope = 0x02, 50 51 /// \brief This is a while, do, for, which can have continue statements 52 /// embedded into it. 53 ContinueScope = 0x04, 54 55 /// \brief This is a scope that can contain a declaration. Some scopes 56 /// just contain loop constructs but don't contain decls. 57 DeclScope = 0x08, 58 59 /// \brief The controlling scope in a if/switch/while/for statement. 60 ControlScope = 0x10, 61 62 /// \brief The scope of a struct/union/class definition. 63 ClassScope = 0x20, 64 65 /// \brief This is a scope that corresponds to a block/closure object. 66 /// Blocks serve as top-level scopes for some objects like labels, they 67 /// also prevent things like break and continue. BlockScopes always have 68 /// the FnScope and DeclScope flags set as well. 69 BlockScope = 0x40, 70 71 /// \brief This is a scope that corresponds to the 72 /// template parameters of a C++ template. Template parameter 73 /// scope starts at the 'template' keyword and ends when the 74 /// template declaration ends. 75 TemplateParamScope = 0x80, 76 77 /// \brief This is a scope that corresponds to the 78 /// parameters within a function prototype. 79 FunctionPrototypeScope = 0x100, 80 81 /// \brief This is a scope that corresponds to the parameters within 82 /// a function prototype for a function declaration (as opposed to any 83 /// other kind of function declarator). Always has FunctionPrototypeScope 84 /// set as well. 85 FunctionDeclarationScope = 0x200, 86 87 /// \brief This is a scope that corresponds to the Objective-C 88 /// \@catch statement. 89 AtCatchScope = 0x400, 90 91 /// \brief This scope corresponds to an Objective-C method body. 92 /// It always has FnScope and DeclScope set as well. 93 ObjCMethodScope = 0x800, 94 95 /// \brief This is a scope that corresponds to a switch statement. 96 SwitchScope = 0x1000, 97 98 /// \brief This is the scope of a C++ try statement. 99 TryScope = 0x2000, 100 101 /// \brief This is the scope for a function-level C++ try or catch scope. 102 FnTryCatchScope = 0x4000, 103 104 /// \brief This is the scope of OpenMP executable directive 105 OpenMPDirectiveScope = 0x8000 106 }; 107private: 108 /// The parent scope for this scope. This is null for the translation-unit 109 /// scope. 110 Scope *AnyParent; 111 112 /// Depth - This is the depth of this scope. The translation-unit scope has 113 /// depth 0. 114 unsigned short Depth; 115 116 /// Flags - This contains a set of ScopeFlags, which indicates how the scope 117 /// interrelates with other control flow statements. 118 unsigned short Flags; 119 120 /// \brief Declarations with static linkage are mangled with the number of 121 /// scopes seen as a component. 122 unsigned short MSLocalManglingNumber; 123 124 /// PrototypeDepth - This is the number of function prototype scopes 125 /// enclosing this scope, including this scope. 126 unsigned short PrototypeDepth; 127 128 /// PrototypeIndex - This is the number of parameters currently 129 /// declared in this scope. 130 unsigned short PrototypeIndex; 131 132 /// FnParent - If this scope has a parent scope that is a function body, this 133 /// pointer is non-null and points to it. This is used for label processing. 134 Scope *FnParent; 135 Scope *MSLocalManglingParent; 136 137 /// BreakParent/ContinueParent - This is a direct link to the innermost 138 /// BreakScope/ContinueScope which contains the contents of this scope 139 /// for control flow purposes (and might be this scope itself), or null 140 /// if there is no such scope. 141 Scope *BreakParent, *ContinueParent; 142 143 /// BlockParent - This is a direct link to the immediately containing 144 /// BlockScope if this scope is not one, or null if there is none. 145 Scope *BlockParent; 146 147 /// TemplateParamParent - This is a direct link to the 148 /// immediately containing template parameter scope. In the 149 /// case of nested templates, template parameter scopes can have 150 /// other template parameter scopes as parents. 151 Scope *TemplateParamParent; 152 153 /// DeclsInScope - This keeps track of all declarations in this scope. When 154 /// the declaration is added to the scope, it is set as the current 155 /// declaration for the identifier in the IdentifierTable. When the scope is 156 /// popped, these declarations are removed from the IdentifierTable's notion 157 /// of current declaration. It is up to the current Action implementation to 158 /// implement these semantics. 159 typedef llvm::SmallPtrSet<Decl *, 32> DeclSetTy; 160 DeclSetTy DeclsInScope; 161 162 /// The DeclContext with which this scope is associated. For 163 /// example, the entity of a class scope is the class itself, the 164 /// entity of a function scope is a function, etc. 165 DeclContext *Entity; 166 167 typedef SmallVector<UsingDirectiveDecl *, 2> UsingDirectivesTy; 168 UsingDirectivesTy UsingDirectives; 169 170 /// \brief Used to determine if errors occurred in this scope. 171 DiagnosticErrorTrap ErrorTrap; 172 173 /// A lattice consisting of undefined, a single NRVO candidate variable in 174 /// this scope, or over-defined. The bit is true when over-defined. 175 llvm::PointerIntPair<VarDecl *, 1, bool> NRVO; 176 177public: 178 Scope(Scope *Parent, unsigned ScopeFlags, DiagnosticsEngine &Diag) 179 : ErrorTrap(Diag) { 180 Init(Parent, ScopeFlags); 181 } 182 183 /// getFlags - Return the flags for this scope. 184 /// 185 unsigned getFlags() const { return Flags; } 186 void setFlags(unsigned F) { Flags = F; } 187 188 /// isBlockScope - Return true if this scope correspond to a closure. 189 bool isBlockScope() const { return Flags & BlockScope; } 190 191 /// getParent - Return the scope that this is nested in. 192 /// 193 const Scope *getParent() const { return AnyParent; } 194 Scope *getParent() { return AnyParent; } 195 196 /// getFnParent - Return the closest scope that is a function body. 197 /// 198 const Scope *getFnParent() const { return FnParent; } 199 Scope *getFnParent() { return FnParent; } 200 201 const Scope *getMSLocalManglingParent() const { 202 return MSLocalManglingParent; 203 } 204 Scope *getMSLocalManglingParent() { return MSLocalManglingParent; } 205 206 /// getContinueParent - Return the closest scope that a continue statement 207 /// would be affected by. 208 Scope *getContinueParent() { 209 return ContinueParent; 210 } 211 212 const Scope *getContinueParent() const { 213 return const_cast<Scope*>(this)->getContinueParent(); 214 } 215 216 /// getBreakParent - Return the closest scope that a break statement 217 /// would be affected by. 218 Scope *getBreakParent() { 219 return BreakParent; 220 } 221 const Scope *getBreakParent() const { 222 return const_cast<Scope*>(this)->getBreakParent(); 223 } 224 225 Scope *getBlockParent() { return BlockParent; } 226 const Scope *getBlockParent() const { return BlockParent; } 227 228 Scope *getTemplateParamParent() { return TemplateParamParent; } 229 const Scope *getTemplateParamParent() const { return TemplateParamParent; } 230 231 /// Returns the number of function prototype scopes in this scope 232 /// chain. 233 unsigned getFunctionPrototypeDepth() const { 234 return PrototypeDepth; 235 } 236 237 /// Return the number of parameters declared in this function 238 /// prototype, increasing it by one for the next call. 239 unsigned getNextFunctionPrototypeIndex() { 240 assert(isFunctionPrototypeScope()); 241 return PrototypeIndex++; 242 } 243 244 typedef llvm::iterator_range<DeclSetTy::iterator> decl_range; 245 decl_range decls() const { 246 return decl_range(DeclsInScope.begin(), DeclsInScope.end()); 247 } 248 bool decl_empty() const { return DeclsInScope.empty(); } 249 250 void AddDecl(Decl *D) { 251 DeclsInScope.insert(D); 252 } 253 254 void RemoveDecl(Decl *D) { 255 DeclsInScope.erase(D); 256 } 257 258 void incrementMSLocalManglingNumber() { 259 if (Scope *MSLMP = getMSLocalManglingParent()) 260 MSLMP->MSLocalManglingNumber += 1; 261 } 262 263 void decrementMSLocalManglingNumber() { 264 if (Scope *MSLMP = getMSLocalManglingParent()) 265 MSLMP->MSLocalManglingNumber -= 1; 266 } 267 268 unsigned getMSLocalManglingNumber() const { 269 if (const Scope *MSLMP = getMSLocalManglingParent()) 270 return MSLMP->MSLocalManglingNumber; 271 return 1; 272 } 273 274 /// isDeclScope - Return true if this is the scope that the specified decl is 275 /// declared in. 276 bool isDeclScope(Decl *D) { 277 return DeclsInScope.count(D) != 0; 278 } 279 280 DeclContext *getEntity() const { return Entity; } 281 void setEntity(DeclContext *E) { Entity = E; } 282 283 bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); } 284 285 bool hasUnrecoverableErrorOccurred() const { 286 return ErrorTrap.hasUnrecoverableErrorOccurred(); 287 } 288 289 /// isClassScope - Return true if this scope is a class/struct/union scope. 290 bool isClassScope() const { 291 return (getFlags() & Scope::ClassScope); 292 } 293 294 /// isInCXXInlineMethodScope - Return true if this scope is a C++ inline 295 /// method scope or is inside one. 296 bool isInCXXInlineMethodScope() const { 297 if (const Scope *FnS = getFnParent()) { 298 assert(FnS->getParent() && "TUScope not created?"); 299 return FnS->getParent()->isClassScope(); 300 } 301 return false; 302 } 303 304 /// isInObjcMethodScope - Return true if this scope is, or is contained in, an 305 /// Objective-C method body. Note that this method is not constant time. 306 bool isInObjcMethodScope() const { 307 for (const Scope *S = this; S; S = S->getParent()) { 308 // If this scope is an objc method scope, then we succeed. 309 if (S->getFlags() & ObjCMethodScope) 310 return true; 311 } 312 return false; 313 } 314 315 /// isInObjcMethodOuterScope - Return true if this scope is an 316 /// Objective-C method outer most body. 317 bool isInObjcMethodOuterScope() const { 318 if (const Scope *S = this) { 319 // If this scope is an objc method scope, then we succeed. 320 if (S->getFlags() & ObjCMethodScope) 321 return true; 322 } 323 return false; 324 } 325 326 327 /// isTemplateParamScope - Return true if this scope is a C++ 328 /// template parameter scope. 329 bool isTemplateParamScope() const { 330 return getFlags() & Scope::TemplateParamScope; 331 } 332 333 /// isFunctionPrototypeScope - Return true if this scope is a 334 /// function prototype scope. 335 bool isFunctionPrototypeScope() const { 336 return getFlags() & Scope::FunctionPrototypeScope; 337 } 338 339 /// isAtCatchScope - Return true if this scope is \@catch. 340 bool isAtCatchScope() const { 341 return getFlags() & Scope::AtCatchScope; 342 } 343 344 /// isSwitchScope - Return true if this scope is a switch scope. 345 bool isSwitchScope() const { 346 for (const Scope *S = this; S; S = S->getParent()) { 347 if (S->getFlags() & Scope::SwitchScope) 348 return true; 349 else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope | 350 Scope::BlockScope | Scope::TemplateParamScope | 351 Scope::FunctionPrototypeScope | 352 Scope::AtCatchScope | Scope::ObjCMethodScope)) 353 return false; 354 } 355 return false; 356 } 357 358 /// \brief Determines whether this scope is the OpenMP directive scope 359 bool isOpenMPDirectiveScope() const { 360 return (getFlags() & Scope::OpenMPDirectiveScope); 361 } 362 363 /// \brief Determine whether this scope is a C++ 'try' block. 364 bool isTryScope() const { return getFlags() & Scope::TryScope; } 365 366 /// containedInPrototypeScope - Return true if this or a parent scope 367 /// is a FunctionPrototypeScope. 368 bool containedInPrototypeScope() const; 369 370 void PushUsingDirective(UsingDirectiveDecl *UDir) { 371 UsingDirectives.push_back(UDir); 372 } 373 374 typedef llvm::iterator_range<UsingDirectivesTy::iterator> 375 using_directives_range; 376 377 using_directives_range using_directives() { 378 return using_directives_range(UsingDirectives.begin(), 379 UsingDirectives.end()); 380 } 381 382 void addNRVOCandidate(VarDecl *VD) { 383 if (NRVO.getInt()) 384 return; 385 if (NRVO.getPointer() == nullptr) { 386 NRVO.setPointer(VD); 387 return; 388 } 389 if (NRVO.getPointer() != VD) 390 setNoNRVO(); 391 } 392 393 void setNoNRVO() { 394 NRVO.setInt(1); 395 NRVO.setPointer(nullptr); 396 } 397 398 void mergeNRVOIntoParent(); 399 400 /// Init - This is used by the parser to implement scope caching. 401 /// 402 void Init(Scope *parent, unsigned flags); 403 404 /// \brief Sets up the specified scope flags and adjusts the scope state 405 /// variables accordingly. 406 /// 407 void AddFlags(unsigned Flags); 408 409 void dumpImpl(raw_ostream &OS) const; 410 void dump() const; 411}; 412 413} // end namespace clang 414 415#endif 416