Scope.h revision d661d50118716e9695af5a893a2df45e87a6b3c8 
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    /// \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    /// \brief This is the scope of OpenMP executable directive
97    OpenMPDirectiveScope = 0x8000
98  };
99private:
100  /// The parent scope for this scope.  This is null for the translation-unit
101  /// scope.
102  Scope *AnyParent;
103
104  /// Depth - This is the depth of this scope.  The translation-unit scope has
105  /// depth 0.
106  unsigned short Depth;
107
108  /// Flags - This contains a set of ScopeFlags, which indicates how the scope
109  /// interrelates with other control flow statements.
110  unsigned short Flags;
111
112  /// PrototypeDepth - This is the number of function prototype scopes
113  /// enclosing this scope, including this scope.
114  unsigned short PrototypeDepth;
115
116  /// PrototypeIndex - This is the number of parameters currently
117  /// declared in this scope.
118  unsigned short PrototypeIndex;
119
120  /// FnParent - If this scope has a parent scope that is a function body, this
121  /// pointer is non-null and points to it.  This is used for label processing.
122  Scope *FnParent;
123
124  /// BreakParent/ContinueParent - This is a direct link to the innermost
125  /// BreakScope/ContinueScope which contains the contents of this scope
126  /// for control flow purposes (and might be this scope itself), or null
127  /// if there is no such scope.
128  Scope *BreakParent, *ContinueParent;
129
130  /// BlockParent - This is a direct link to the immediately containing
131  /// BlockScope if this scope is not one, or null if there is none.
132  Scope *BlockParent;
133
134  /// TemplateParamParent - This is a direct link to the
135  /// immediately containing template parameter scope. In the
136  /// case of nested templates, template parameter scopes can have
137  /// other template parameter scopes as parents.
138  Scope *TemplateParamParent;
139
140  /// DeclsInScope - This keeps track of all declarations in this scope.  When
141  /// the declaration is added to the scope, it is set as the current
142  /// declaration for the identifier in the IdentifierTable.  When the scope is
143  /// popped, these declarations are removed from the IdentifierTable's notion
144  /// of current declaration.  It is up to the current Action implementation to
145  /// implement these semantics.
146  typedef llvm::SmallPtrSet<Decl *, 32> DeclSetTy;
147  DeclSetTy DeclsInScope;
148
149  /// The DeclContext with which this scope is associated. For
150  /// example, the entity of a class scope is the class itself, the
151  /// entity of a function scope is a function, etc.
152  DeclContext *Entity;
153
154  typedef SmallVector<UsingDirectiveDecl *, 2> UsingDirectivesTy;
155  UsingDirectivesTy UsingDirectives;
156
157  /// \brief Used to determine if errors occurred in this scope.
158  DiagnosticErrorTrap ErrorTrap;
159
160public:
161  Scope(Scope *Parent, unsigned ScopeFlags, DiagnosticsEngine &Diag)
162    : ErrorTrap(Diag) {
163    Init(Parent, ScopeFlags);
164  }
165
166  /// getFlags - Return the flags for this scope.
167  ///
168  unsigned getFlags() const { return Flags; }
169  void setFlags(unsigned F) { Flags = F; }
170
171  /// isBlockScope - Return true if this scope correspond to a closure.
172  bool isBlockScope() const { return Flags & BlockScope; }
173
174  /// getParent - Return the scope that this is nested in.
175  ///
176  const Scope *getParent() const { return AnyParent; }
177  Scope *getParent() { return AnyParent; }
178
179  /// getFnParent - Return the closest scope that is a function body.
180  ///
181  const Scope *getFnParent() const { return FnParent; }
182  Scope *getFnParent() { return FnParent; }
183
184  /// getContinueParent - Return the closest scope that a continue statement
185  /// would be affected by.
186  Scope *getContinueParent() {
187    return ContinueParent;
188  }
189
190  const Scope *getContinueParent() const {
191    return const_cast<Scope*>(this)->getContinueParent();
192  }
193
194  /// getBreakParent - Return the closest scope that a break statement
195  /// would be affected by.
196  Scope *getBreakParent() {
197    return BreakParent;
198  }
199  const Scope *getBreakParent() const {
200    return const_cast<Scope*>(this)->getBreakParent();
201  }
202
203  Scope *getBlockParent() { return BlockParent; }
204  const Scope *getBlockParent() const { return BlockParent; }
205
206  Scope *getTemplateParamParent() { return TemplateParamParent; }
207  const Scope *getTemplateParamParent() const { return TemplateParamParent; }
208
209  /// Returns the number of function prototype scopes in this scope
210  /// chain.
211  unsigned getFunctionPrototypeDepth() const {
212    return PrototypeDepth;
213  }
214
215  /// Return the number of parameters declared in this function
216  /// prototype, increasing it by one for the next call.
217  unsigned getNextFunctionPrototypeIndex() {
218    assert(isFunctionPrototypeScope());
219    return PrototypeIndex++;
220  }
221
222  typedef DeclSetTy::iterator decl_iterator;
223  decl_iterator decl_begin() const { return DeclsInScope.begin(); }
224  decl_iterator decl_end()   const { return DeclsInScope.end(); }
225  bool decl_empty()          const { return DeclsInScope.empty(); }
226
227  void AddDecl(Decl *D) {
228    DeclsInScope.insert(D);
229  }
230
231  void RemoveDecl(Decl *D) {
232    DeclsInScope.erase(D);
233  }
234
235  /// isDeclScope - Return true if this is the scope that the specified decl is
236  /// declared in.
237  bool isDeclScope(Decl *D) {
238    return DeclsInScope.count(D) != 0;
239  }
240
241  DeclContext *getEntity() const { return Entity; }
242  void setEntity(DeclContext *E) { Entity = E; }
243
244  bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); }
245
246  bool hasUnrecoverableErrorOccurred() const {
247    return ErrorTrap.hasUnrecoverableErrorOccurred();
248  }
249
250  /// isClassScope - Return true if this scope is a class/struct/union scope.
251  bool isClassScope() const {
252    return (getFlags() & Scope::ClassScope);
253  }
254
255  /// isInCXXInlineMethodScope - Return true if this scope is a C++ inline
256  /// method scope or is inside one.
257  bool isInCXXInlineMethodScope() const {
258    if (const Scope *FnS = getFnParent()) {
259      assert(FnS->getParent() && "TUScope not created?");
260      return FnS->getParent()->isClassScope();
261    }
262    return false;
263  }
264
265  /// isInObjcMethodScope - Return true if this scope is, or is contained in, an
266  /// Objective-C method body.  Note that this method is not constant time.
267  bool isInObjcMethodScope() const {
268    for (const Scope *S = this; S; S = S->getParent()) {
269      // If this scope is an objc method scope, then we succeed.
270      if (S->getFlags() & ObjCMethodScope)
271        return true;
272    }
273    return false;
274  }
275
276  /// isTemplateParamScope - Return true if this scope is a C++
277  /// template parameter scope.
278  bool isTemplateParamScope() const {
279    return getFlags() & Scope::TemplateParamScope;
280  }
281
282  /// isFunctionPrototypeScope - Return true if this scope is a
283  /// function prototype scope.
284  bool isFunctionPrototypeScope() const {
285    return getFlags() & Scope::FunctionPrototypeScope;
286  }
287
288  /// isAtCatchScope - Return true if this scope is \@catch.
289  bool isAtCatchScope() const {
290    return getFlags() & Scope::AtCatchScope;
291  }
292
293  /// isSwitchScope - Return true if this scope is a switch scope.
294  bool isSwitchScope() const {
295    for (const Scope *S = this; S; S = S->getParent()) {
296      if (S->getFlags() & Scope::SwitchScope)
297        return true;
298      else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope |
299                                Scope::BlockScope | Scope::TemplateParamScope |
300                                Scope::FunctionPrototypeScope |
301                                Scope::AtCatchScope | Scope::ObjCMethodScope))
302        return false;
303    }
304    return false;
305  }
306
307  /// \brief Determines whether this scope is the OpenMP directive scope
308  bool isOpenMPDirectiveScope() const {
309    return (getFlags() & Scope::OpenMPDirectiveScope);
310  }
311
312  /// \brief Determine whether this scope is a C++ 'try' block.
313  bool isTryScope() const { return getFlags() & Scope::TryScope; }
314
315  /// containedInPrototypeScope - Return true if this or a parent scope
316  /// is a FunctionPrototypeScope.
317  bool containedInPrototypeScope() const;
318
319  typedef UsingDirectivesTy::iterator udir_iterator;
320  typedef UsingDirectivesTy::const_iterator const_udir_iterator;
321
322  void PushUsingDirective(UsingDirectiveDecl *UDir) {
323    UsingDirectives.push_back(UDir);
324  }
325
326  udir_iterator using_directives_begin() {
327    return UsingDirectives.begin();
328  }
329
330  udir_iterator using_directives_end() {
331    return UsingDirectives.end();
332  }
333
334  const_udir_iterator using_directives_begin() const {
335    return UsingDirectives.begin();
336  }
337
338  const_udir_iterator using_directives_end() const {
339    return UsingDirectives.end();
340  }
341
342  /// Init - This is used by the parser to implement scope caching.
343  ///
344  void Init(Scope *parent, unsigned flags);
345};
346
347}  // end namespace clang
348
349#endif
350