Scope.h revision cefc3afac14d29de5aba7810cc8fe6c858949e9d 
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
21namespace clang {
22
23class Decl;
24class 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///
30class Scope {
31public:
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    /// FnScope - This indicates that the scope corresponds to a function, which
36    /// means that labels are set here.
37    FnScope       = 0x01,
38
39    /// BreakScope - This is a while,do,switch,for, etc that can have break
40    /// stmts embedded into it.
41    BreakScope    = 0x02,
42
43    /// ContinueScope - This is a while,do,for, which can have continue
44    /// stmt embedded into it.
45    ContinueScope = 0x04,
46
47    /// DeclScope - 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    /// ControlScope - The controlling scope in a if/switch/while/for statement.
52    ControlScope = 0x10,
53
54    /// ClassScope - The scope of a struct/union/class definition.
55    ClassScope = 0x20,
56
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.
61    BlockScope = 0x40,
62
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,
68
69    /// FunctionPrototypeScope - This is a scope that corresponds to the
70    /// parameters within a function prototype.
71    FunctionPrototypeScope = 0x100,
72
73    /// AtCatchScope - This is a scope that corresponds to the Objective-C
74    /// @catch statement.
75    AtCatchScope = 0x200,
76
77    /// ObjCMethodScope - This scope corresponds to an Objective-C method body.
78    /// It always has FnScope and DeclScope set as well.
79    ObjCMethodScope = 0x400,
80
81    /// SwitchScope - This is a scope that corresponds to a switch statement.
82    SwitchScope = 0x800,
83
84    /// TryScope - This is the scope of a C++ try statement.
85    TryScope = 0x1000
86  };
87private:
88  /// The parent scope for this scope.  This is null for the translation-unit
89  /// scope.
90  Scope *AnyParent;
91
92  /// Depth - This is the depth of this scope.  The translation-unit scope has
93  /// depth 0.
94  unsigned short Depth;
95
96  /// Flags - This contains a set of ScopeFlags, which indicates how the scope
97  /// interrelates with other control flow statements.
98  unsigned short Flags;
99
100  /// PrototypeDepth - This is the number of function prototype scopes
101  /// enclosing this scope, including this scope.
102  unsigned short PrototypeDepth;
103
104  /// PrototypeIndex - This is the number of parameters currently
105  /// declared in this scope.
106  unsigned short PrototypeIndex;
107
108  /// FnParent - If this scope has a parent scope that is a function body, this
109  /// pointer is non-null and points to it.  This is used for label processing.
110  Scope *FnParent;
111
112  /// BreakParent/ContinueParent - This is a direct link to the innermost
113  /// BreakScope/ContinueScope which contains the contents of this scope
114  /// for control flow purposes (and might be this scope itself), or null
115  /// if there is no such scope.
116  Scope *BreakParent, *ContinueParent;
117
118  /// BlockParent - This is a direct link to the immediately containing
119  /// BlockScope if this scope is not one, or null if there is none.
120  Scope *BlockParent;
121
122  /// TemplateParamParent - This is a direct link to the
123  /// immediately containing template parameter scope. In the
124  /// case of nested templates, template parameter scopes can have
125  /// other template parameter scopes as parents.
126  Scope *TemplateParamParent;
127
128  /// DeclsInScope - This keeps track of all declarations in this scope.  When
129  /// the declaration is added to the scope, it is set as the current
130  /// declaration for the identifier in the IdentifierTable.  When the scope is
131  /// popped, these declarations are removed from the IdentifierTable's notion
132  /// of current declaration.  It is up to the current Action implementation to
133  /// implement these semantics.
134  typedef llvm::SmallPtrSet<Decl *, 32> DeclSetTy;
135  DeclSetTy DeclsInScope;
136
137  /// Entity - The entity with which this scope is associated. For
138  /// example, the entity of a class scope is the class itself, the
139  /// entity of a function scope is a function, etc. This field is
140  /// maintained by the Action implementation.
141  void *Entity;
142
143  typedef SmallVector<UsingDirectiveDecl *, 2> UsingDirectivesTy;
144  UsingDirectivesTy UsingDirectives;
145
146  /// \brief Used to determine if errors occurred in this scope.
147  DiagnosticErrorTrap ErrorTrap;
148
149public:
150  Scope(Scope *Parent, unsigned ScopeFlags, DiagnosticsEngine &Diag)
151    : ErrorTrap(Diag) {
152    Init(Parent, ScopeFlags);
153  }
154
155  /// getFlags - Return the flags for this scope.
156  ///
157  unsigned getFlags() const { return Flags; }
158  void setFlags(unsigned F) { Flags = F; }
159
160  /// isBlockScope - Return true if this scope correspond to a closure.
161  bool isBlockScope() const { return Flags & BlockScope; }
162
163  /// getParent - Return the scope that this is nested in.
164  ///
165  const Scope *getParent() const { return AnyParent; }
166  Scope *getParent() { return AnyParent; }
167
168  /// getFnParent - Return the closest scope that is a function body.
169  ///
170  const Scope *getFnParent() const { return FnParent; }
171  Scope *getFnParent() { return FnParent; }
172
173  /// getContinueParent - Return the closest scope that a continue statement
174  /// would be affected by.
175  Scope *getContinueParent() {
176    return ContinueParent;
177  }
178
179  const Scope *getContinueParent() const {
180    return const_cast<Scope*>(this)->getContinueParent();
181  }
182
183  /// getBreakParent - Return the closest scope that a break statement
184  /// would be affected by.
185  Scope *getBreakParent() {
186    return BreakParent;
187  }
188  const Scope *getBreakParent() const {
189    return const_cast<Scope*>(this)->getBreakParent();
190  }
191
192  Scope *getBlockParent() { return BlockParent; }
193  const Scope *getBlockParent() const { return BlockParent; }
194
195  Scope *getTemplateParamParent() { return TemplateParamParent; }
196  const Scope *getTemplateParamParent() const { return TemplateParamParent; }
197
198  /// Returns the number of function prototype scopes in this scope
199  /// chain.
200  unsigned getFunctionPrototypeDepth() const {
201    return PrototypeDepth;
202  }
203
204  /// Return the number of parameters declared in this function
205  /// prototype, increasing it by one for the next call.
206  unsigned getNextFunctionPrototypeIndex() {
207    assert(isFunctionPrototypeScope());
208    return PrototypeIndex++;
209  }
210
211  typedef DeclSetTy::iterator decl_iterator;
212  decl_iterator decl_begin() const { return DeclsInScope.begin(); }
213  decl_iterator decl_end()   const { return DeclsInScope.end(); }
214  bool decl_empty()          const { return DeclsInScope.empty(); }
215
216  void AddDecl(Decl *D) {
217    DeclsInScope.insert(D);
218  }
219
220  void RemoveDecl(Decl *D) {
221    DeclsInScope.erase(D);
222  }
223
224  /// isDeclScope - Return true if this is the scope that the specified decl is
225  /// declared in.
226  bool isDeclScope(Decl *D) {
227    return DeclsInScope.count(D) != 0;
228  }
229
230  void* getEntity() const { return Entity; }
231  void setEntity(void *E) { Entity = E; }
232
233  bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); }
234
235  /// isClassScope - Return true if this scope is a class/struct/union scope.
236  bool isClassScope() const {
237    return (getFlags() & Scope::ClassScope);
238  }
239
240  /// isInCXXInlineMethodScope - Return true if this scope is a C++ inline
241  /// method scope or is inside one.
242  bool isInCXXInlineMethodScope() const {
243    if (const Scope *FnS = getFnParent()) {
244      assert(FnS->getParent() && "TUScope not created?");
245      return FnS->getParent()->isClassScope();
246    }
247    return false;
248  }
249
250  /// isInObjcMethodScope - Return true if this scope is, or is contained in, an
251  /// Objective-C method body.  Note that this method is not constant time.
252  bool isInObjcMethodScope() const {
253    for (const Scope *S = this; S; S = S->getParent()) {
254      // If this scope is an objc method scope, then we succeed.
255      if (S->getFlags() & ObjCMethodScope)
256        return true;
257    }
258    return false;
259  }
260
261  /// isTemplateParamScope - Return true if this scope is a C++
262  /// template parameter scope.
263  bool isTemplateParamScope() const {
264    return getFlags() & Scope::TemplateParamScope;
265  }
266
267  /// isFunctionPrototypeScope - Return true if this scope is a
268  /// function prototype scope.
269  bool isFunctionPrototypeScope() const {
270    return getFlags() & Scope::FunctionPrototypeScope;
271  }
272
273  /// isAtCatchScope - Return true if this scope is @catch.
274  bool isAtCatchScope() const {
275    return getFlags() & Scope::AtCatchScope;
276  }
277
278  /// isSwitchScope - Return true if this scope is a switch scope.
279  bool isSwitchScope() const {
280    for (const Scope *S = this; S; S = S->getParent()) {
281      if (S->getFlags() & Scope::SwitchScope)
282        return true;
283      else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope |
284                                Scope::BlockScope | Scope::TemplateParamScope |
285                                Scope::FunctionPrototypeScope |
286                                Scope::AtCatchScope | Scope::ObjCMethodScope))
287        return false;
288    }
289    return false;
290  }
291
292  /// \brief Determine whether this scope is a C++ 'try' block.
293  bool isTryScope() const { return getFlags() & Scope::TryScope; }
294
295  /// containedInPrototypeScope - Return true if this or a parent scope
296  /// is a FunctionPrototypeScope.
297  bool containedInPrototypeScope() const;
298
299  typedef UsingDirectivesTy::iterator udir_iterator;
300  typedef UsingDirectivesTy::const_iterator const_udir_iterator;
301
302  void PushUsingDirective(UsingDirectiveDecl *UDir) {
303    UsingDirectives.push_back(UDir);
304  }
305
306  udir_iterator using_directives_begin() {
307    return UsingDirectives.begin();
308  }
309
310  udir_iterator using_directives_end() {
311    return UsingDirectives.end();
312  }
313
314  const_udir_iterator using_directives_begin() const {
315    return UsingDirectives.begin();
316  }
317
318  const_udir_iterator using_directives_end() const {
319    return UsingDirectives.end();
320  }
321
322  /// Init - This is used by the parser to implement scope caching.
323  ///
324  void Init(Scope *parent, unsigned flags);
325};
326
327}  // end namespace clang
328
329#endif
330