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, BreakScope, ContinueScope, 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
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 /// ThisScope - This is the scope of a struct/union/class definition,
85 /// outside of any member function definition, where 'this' is nonetheless
89 /// TryScope - This is the scope of a C++ try statement.
93 /// The parent scope for this scope. This is null for the translation-unit
97 /// Depth - This is the depth of this scope. The translation-unit scope has
101 /// Flags - This contains a set of ScopeFlags, which indicates how the scope
102 /// interrelates with other control flow statements.
103 unsigned short Flags;
105 /// PrototypeDepth - This is the number of function prototype scopes
106 /// enclosing this scope, including this scope.
107 unsigned short PrototypeDepth;
109 /// PrototypeIndex - This is the number of parameters currently
110 /// declared in this scope.
111 unsigned short PrototypeIndex;
113 /// FnParent - If this scope has a parent scope that is a function body, this
114 /// pointer is non-null and points to it. This is used for label processing.
117 /// BreakParent/ContinueParent - This is a direct link to the immediately
118 /// preceding BreakParent/ContinueParent if this scope is not one, or null if
119 /// there is no containing break/continue scope.
120 Scope *BreakParent, *ContinueParent;
122 /// ControlParent - This is a direct link to the immediately
123 /// preceding ControlParent if this scope is not one, or null if
124 /// there is no containing control scope.
125 Scope *ControlParent;
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.
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;
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;
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.
152 typedef llvm::SmallVector<UsingDirectiveDecl *, 2> UsingDirectivesTy;
153 UsingDirectivesTy UsingDirectives;
155 /// \brief Used to determine if errors occurred in this scope.
156 DiagnosticErrorTrap ErrorTrap;
159 Scope(Scope *Parent, unsigned ScopeFlags, Diagnostic &Diag)
161 Init(Parent, ScopeFlags);
164 /// getFlags - Return the flags for this scope.
166 unsigned getFlags() const { return Flags; }
167 void setFlags(unsigned F) { Flags = F; }
169 /// isBlockScope - Return true if this scope correspond to a closure.
170 bool isBlockScope() const { return Flags & BlockScope; }
172 /// getParent - Return the scope that this is nested in.
174 const Scope *getParent() const { return AnyParent; }
175 Scope *getParent() { return AnyParent; }
177 /// getFnParent - Return the closest scope that is a function body.
179 const Scope *getFnParent() const { return FnParent; }
180 Scope *getFnParent() { return FnParent; }
182 /// getContinueParent - Return the closest scope that a continue statement
183 /// would be affected by. If the closest scope is a closure scope, we know
184 /// that there is no loop *inside* the closure.
185 Scope *getContinueParent() {
186 if (ContinueParent && !ContinueParent->isBlockScope())
187 return ContinueParent;
191 const Scope *getContinueParent() const {
192 return const_cast<Scope*>(this)->getContinueParent();
195 /// getBreakParent - Return the closest scope that a break statement
196 /// would be affected by. If the closest scope is a block scope, we know
197 /// that there is no loop *inside* the block.
198 Scope *getBreakParent() {
199 if (BreakParent && !BreakParent->isBlockScope())
203 const Scope *getBreakParent() const {
204 return const_cast<Scope*>(this)->getBreakParent();
207 Scope *getControlParent() { return ControlParent; }
208 const Scope *getControlParent() const { return ControlParent; }
210 Scope *getBlockParent() { return BlockParent; }
211 const Scope *getBlockParent() const { return BlockParent; }
213 Scope *getTemplateParamParent() { return TemplateParamParent; }
214 const Scope *getTemplateParamParent() const { return TemplateParamParent; }
216 /// Returns the number of function prototype scopes in this scope
218 unsigned getFunctionPrototypeDepth() const {
219 return PrototypeDepth;
222 /// Return the number of parameters declared in this function
223 /// prototype, increasing it by one for the next call.
224 unsigned getNextFunctionPrototypeIndex() {
225 assert(isFunctionPrototypeScope());
226 return PrototypeIndex++;
229 typedef DeclSetTy::iterator decl_iterator;
230 decl_iterator decl_begin() const { return DeclsInScope.begin(); }
231 decl_iterator decl_end() const { return DeclsInScope.end(); }
232 bool decl_empty() const { return DeclsInScope.empty(); }
234 void AddDecl(Decl *D) {
235 DeclsInScope.insert(D);
238 void RemoveDecl(Decl *D) {
239 DeclsInScope.erase(D);
242 /// isDeclScope - Return true if this is the scope that the specified decl is
244 bool isDeclScope(Decl *D) {
245 return DeclsInScope.count(D) != 0;
248 void* getEntity() const { return Entity; }
249 void setEntity(void *E) { Entity = E; }
251 bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); }
253 /// isClassScope - Return true if this scope is a class/struct/union scope.
254 bool isClassScope() const {
255 return (getFlags() & Scope::ClassScope);
258 /// isInCXXInlineMethodScope - Return true if this scope is a C++ inline
259 /// method scope or is inside one.
260 bool isInCXXInlineMethodScope() const {
261 if (const Scope *FnS = getFnParent()) {
262 assert(FnS->getParent() && "TUScope not created?");
263 return FnS->getParent()->isClassScope();
268 /// isInObjcMethodScope - Return true if this scope is, or is contained in, an
269 /// Objective-C method body. Note that this method is not constant time.
270 bool isInObjcMethodScope() const {
271 for (const Scope *S = this; S; S = S->getParent()) {
272 // If this scope is an objc method scope, then we succeed.
273 if (S->getFlags() & ObjCMethodScope)
279 /// isTemplateParamScope - Return true if this scope is a C++
280 /// template parameter scope.
281 bool isTemplateParamScope() const {
282 return getFlags() & Scope::TemplateParamScope;
285 /// isFunctionPrototypeScope - Return true if this scope is a
286 /// function prototype scope.
287 bool isFunctionPrototypeScope() const {
288 return getFlags() & Scope::FunctionPrototypeScope;
291 /// isAtCatchScope - Return true if this scope is @catch.
292 bool isAtCatchScope() const {
293 return getFlags() & Scope::AtCatchScope;
296 /// isSwitchScope - Return true if this scope is a switch scope.
297 bool isSwitchScope() const {
298 for (const Scope *S = this; S; S = S->getParent()) {
299 if (S->getFlags() & Scope::SwitchScope)
301 else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope |
302 Scope::BlockScope | Scope::TemplateParamScope |
303 Scope::FunctionPrototypeScope |
304 Scope::AtCatchScope | Scope::ObjCMethodScope))
310 /// \brief Determine whether this scope is a C++ 'try' block.
311 bool isTryScope() const { return getFlags() & Scope::TryScope; }
313 typedef UsingDirectivesTy::iterator udir_iterator;
314 typedef UsingDirectivesTy::const_iterator const_udir_iterator;
316 void PushUsingDirective(UsingDirectiveDecl *UDir) {
317 UsingDirectives.push_back(UDir);
320 udir_iterator using_directives_begin() {
321 return UsingDirectives.begin();
324 udir_iterator using_directives_end() {
325 return UsingDirectives.end();
328 const_udir_iterator using_directives_begin() const {
329 return UsingDirectives.begin();
332 const_udir_iterator using_directives_end() const {
333 return UsingDirectives.end();
336 /// Init - This is used by the parser to implement scope caching.
338 void Init(Scope *parent, unsigned flags);
341 } // end namespace clang