1 //===--- Scope.h - Scope interface ------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the Scope interface.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_SEMA_SCOPE_H
15 #define LLVM_CLANG_SEMA_SCOPE_H
17 #include "clang/Basic/Diagnostic.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/SmallVector.h"
24 class UsingDirectiveDecl;
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
32 /// ScopeFlags - These are bitfields that are or'd together when creating a
33 /// scope, which defines the sorts of things the scope contains.
35 /// FnScope - This indicates that the scope corresponds to a function, which
36 /// means that labels are set here.
39 /// BreakScope - This is a while,do,switch,for, etc that can have break
40 /// stmts embedded into it.
43 /// ContinueScope - This is a while,do,for, which can have continue
44 /// stmt embedded into it.
47 /// DeclScope - This is a scope that can contain a declaration. Some scopes
48 /// just contain loop constructs but don't contain decls.
51 /// ControlScope - The controlling scope in a if/switch/while/for statement.
54 /// ClassScope - The scope of a struct/union/class definition.
57 /// BlockScope - 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.
63 /// TemplateParamScope - 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,
69 /// FunctionPrototypeScope - This is a scope that corresponds to the
70 /// parameters within a function prototype.
71 FunctionPrototypeScope = 0x100,
73 /// AtCatchScope - This is a scope that corresponds to the Objective-C
74 /// \@catch statement.
77 /// ObjCMethodScope - This scope corresponds to an Objective-C method body.
78 /// It always has FnScope and DeclScope set as well.
79 ObjCMethodScope = 0x400,
81 /// SwitchScope - This is a scope that corresponds to a switch statement.
84 /// TryScope - This is the scope of a C++ try statement.
87 /// CatchScope - This is the scope of a C++ catch statement.
90 /// FnTryCatchScope - This is the scope for a function-level C++ try or
92 FnTryCatchScope = 0x4000,
94 /// FnTryScope - This is the scope of a function-level C++ try scope.
95 FnTryScope = TryScope | FnTryCatchScope,
97 /// FnCatchScope - This is the scope of a function-level C++ catch scope.
98 FnCatchScope = CatchScope | FnTryCatchScope
101 /// The parent scope for this scope. This is null for the translation-unit
105 /// Depth - This is the depth of this scope. The translation-unit scope has
107 unsigned short Depth;
109 /// Flags - This contains a set of ScopeFlags, which indicates how the scope
110 /// interrelates with other control flow statements.
111 unsigned short Flags;
113 /// PrototypeDepth - This is the number of function prototype scopes
114 /// enclosing this scope, including this scope.
115 unsigned short PrototypeDepth;
117 /// PrototypeIndex - This is the number of parameters currently
118 /// declared in this scope.
119 unsigned short PrototypeIndex;
121 /// FnParent - If this scope has a parent scope that is a function body, this
122 /// pointer is non-null and points to it. This is used for label processing.
125 /// BreakParent/ContinueParent - This is a direct link to the innermost
126 /// BreakScope/ContinueScope which contains the contents of this scope
127 /// for control flow purposes (and might be this scope itself), or null
128 /// if there is no such scope.
129 Scope *BreakParent, *ContinueParent;
131 /// BlockParent - This is a direct link to the immediately containing
132 /// BlockScope if this scope is not one, or null if there is none.
135 /// TemplateParamParent - This is a direct link to the
136 /// immediately containing template parameter scope. In the
137 /// case of nested templates, template parameter scopes can have
138 /// other template parameter scopes as parents.
139 Scope *TemplateParamParent;
141 /// DeclsInScope - This keeps track of all declarations in this scope. When
142 /// the declaration is added to the scope, it is set as the current
143 /// declaration for the identifier in the IdentifierTable. When the scope is
144 /// popped, these declarations are removed from the IdentifierTable's notion
145 /// of current declaration. It is up to the current Action implementation to
146 /// implement these semantics.
147 typedef llvm::SmallPtrSet<Decl *, 32> DeclSetTy;
148 DeclSetTy DeclsInScope;
150 /// Entity - The entity with which this scope is associated. For
151 /// example, the entity of a class scope is the class itself, the
152 /// entity of a function scope is a function, etc. This field is
153 /// maintained by the Action implementation.
156 typedef SmallVector<UsingDirectiveDecl *, 2> UsingDirectivesTy;
157 UsingDirectivesTy UsingDirectives;
159 /// \brief Used to determine if errors occurred in this scope.
160 DiagnosticErrorTrap ErrorTrap;
163 Scope(Scope *Parent, unsigned ScopeFlags, DiagnosticsEngine &Diag)
165 Init(Parent, ScopeFlags);
168 /// getFlags - Return the flags for this scope.
170 unsigned getFlags() const { return Flags; }
171 void setFlags(unsigned F) { Flags = F; }
173 /// isBlockScope - Return true if this scope correspond to a closure.
174 bool isBlockScope() const { return Flags & BlockScope; }
176 /// getParent - Return the scope that this is nested in.
178 const Scope *getParent() const { return AnyParent; }
179 Scope *getParent() { return AnyParent; }
181 /// getFnParent - Return the closest scope that is a function body.
183 const Scope *getFnParent() const { return FnParent; }
184 Scope *getFnParent() { return FnParent; }
186 /// getContinueParent - Return the closest scope that a continue statement
187 /// would be affected by.
188 Scope *getContinueParent() {
189 return ContinueParent;
192 const Scope *getContinueParent() const {
193 return const_cast<Scope*>(this)->getContinueParent();
196 /// getBreakParent - Return the closest scope that a break statement
197 /// would be affected by.
198 Scope *getBreakParent() {
201 const Scope *getBreakParent() const {
202 return const_cast<Scope*>(this)->getBreakParent();
205 Scope *getBlockParent() { return BlockParent; }
206 const Scope *getBlockParent() const { return BlockParent; }
208 Scope *getTemplateParamParent() { return TemplateParamParent; }
209 const Scope *getTemplateParamParent() const { return TemplateParamParent; }
211 /// Returns the number of function prototype scopes in this scope
213 unsigned getFunctionPrototypeDepth() const {
214 return PrototypeDepth;
217 /// Return the number of parameters declared in this function
218 /// prototype, increasing it by one for the next call.
219 unsigned getNextFunctionPrototypeIndex() {
220 assert(isFunctionPrototypeScope());
221 return PrototypeIndex++;
224 typedef DeclSetTy::iterator decl_iterator;
225 decl_iterator decl_begin() const { return DeclsInScope.begin(); }
226 decl_iterator decl_end() const { return DeclsInScope.end(); }
227 bool decl_empty() const { return DeclsInScope.empty(); }
229 void AddDecl(Decl *D) {
230 DeclsInScope.insert(D);
233 void RemoveDecl(Decl *D) {
234 DeclsInScope.erase(D);
237 /// isDeclScope - Return true if this is the scope that the specified decl is
239 bool isDeclScope(Decl *D) {
240 return DeclsInScope.count(D) != 0;
243 void* getEntity() const { return Entity; }
244 void setEntity(void *E) { Entity = E; }
246 bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); }
248 /// isClassScope - Return true if this scope is a class/struct/union scope.
249 bool isClassScope() const {
250 return (getFlags() & Scope::ClassScope);
253 /// isInCXXInlineMethodScope - Return true if this scope is a C++ inline
254 /// method scope or is inside one.
255 bool isInCXXInlineMethodScope() const {
256 if (const Scope *FnS = getFnParent()) {
257 assert(FnS->getParent() && "TUScope not created?");
258 return FnS->getParent()->isClassScope();
263 /// isInObjcMethodScope - Return true if this scope is, or is contained in, an
264 /// Objective-C method body. Note that this method is not constant time.
265 bool isInObjcMethodScope() const {
266 for (const Scope *S = this; S; S = S->getParent()) {
267 // If this scope is an objc method scope, then we succeed.
268 if (S->getFlags() & ObjCMethodScope)
274 /// isTemplateParamScope - Return true if this scope is a C++
275 /// template parameter scope.
276 bool isTemplateParamScope() const {
277 return getFlags() & Scope::TemplateParamScope;
280 /// isFunctionPrototypeScope - Return true if this scope is a
281 /// function prototype scope.
282 bool isFunctionPrototypeScope() const {
283 return getFlags() & Scope::FunctionPrototypeScope;
286 /// isAtCatchScope - Return true if this scope is \@catch.
287 bool isAtCatchScope() const {
288 return getFlags() & Scope::AtCatchScope;
291 /// isSwitchScope - Return true if this scope is a switch scope.
292 bool isSwitchScope() const {
293 for (const Scope *S = this; S; S = S->getParent()) {
294 if (S->getFlags() & Scope::SwitchScope)
296 else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope |
297 Scope::BlockScope | Scope::TemplateParamScope |
298 Scope::FunctionPrototypeScope |
299 Scope::AtCatchScope | Scope::ObjCMethodScope))
305 /// \brief Determine whether this scope is a C++ 'try' block.
306 bool isTryScope() const { return getFlags() & Scope::TryScope; }
308 /// containedInPrototypeScope - Return true if this or a parent scope
309 /// is a FunctionPrototypeScope.
310 bool containedInPrototypeScope() const;
312 typedef UsingDirectivesTy::iterator udir_iterator;
313 typedef UsingDirectivesTy::const_iterator const_udir_iterator;
315 void PushUsingDirective(UsingDirectiveDecl *UDir) {
316 UsingDirectives.push_back(UDir);
319 udir_iterator using_directives_begin() {
320 return UsingDirectives.begin();
323 udir_iterator using_directives_end() {
324 return UsingDirectives.end();
327 const_udir_iterator using_directives_begin() const {
328 return UsingDirectives.begin();
331 const_udir_iterator using_directives_end() const {
332 return UsingDirectives.end();
335 /// Init - This is used by the parser to implement scope caching.
337 void Init(Scope *parent, unsigned flags);
340 } // end namespace clang