clang  6.0.0svn
Scope.h
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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/AST/Decl.h"
18 #include "clang/Basic/Diagnostic.h"
19 #include "llvm/ADT/PointerIntPair.h"
20 #include "llvm/ADT/SmallPtrSet.h"
21 #include "llvm/ADT/SmallVector.h"
22 
23 namespace llvm {
24 
25 class raw_ostream;
26 
27 }
28 
29 namespace clang {
30 
31 class Decl;
32 class UsingDirectiveDecl;
33 class VarDecl;
34 
35 /// Scope - A scope is a transient data structure that is used while parsing the
36 /// program. It assists with resolving identifiers to the appropriate
37 /// declaration.
38 ///
39 class Scope {
40 public:
41  /// ScopeFlags - These are bitfields that are or'd together when creating a
42  /// scope, which defines the sorts of things the scope contains.
43  enum ScopeFlags {
44  /// \brief This indicates that the scope corresponds to a function, which
45  /// means that labels are set here.
46  FnScope = 0x01,
47 
48  /// \brief This is a while, do, switch, for, etc that can have break
49  /// statements embedded into it.
50  BreakScope = 0x02,
51 
52  /// \brief This is a while, do, for, which can have continue statements
53  /// embedded into it.
54  ContinueScope = 0x04,
55 
56  /// \brief This is a scope that can contain a declaration. Some scopes
57  /// just contain loop constructs but don't contain decls.
58  DeclScope = 0x08,
59 
60  /// \brief The controlling scope in a if/switch/while/for statement.
61  ControlScope = 0x10,
62 
63  /// \brief The scope of a struct/union/class definition.
64  ClassScope = 0x20,
65 
66  /// \brief This is a scope that corresponds to a block/closure object.
67  /// Blocks serve as top-level scopes for some objects like labels, they
68  /// also prevent things like break and continue. BlockScopes always have
69  /// the FnScope and DeclScope flags set as well.
70  BlockScope = 0x40,
71 
72  /// \brief This is a scope that corresponds to the
73  /// template parameters of a C++ template. Template parameter
74  /// scope starts at the 'template' keyword and ends when the
75  /// template declaration ends.
76  TemplateParamScope = 0x80,
77 
78  /// \brief This is a scope that corresponds to the
79  /// parameters within a function prototype.
80  FunctionPrototypeScope = 0x100,
81 
82  /// \brief This is a scope that corresponds to the parameters within
83  /// a function prototype for a function declaration (as opposed to any
84  /// other kind of function declarator). Always has FunctionPrototypeScope
85  /// set as well.
86  FunctionDeclarationScope = 0x200,
87 
88  /// \brief This is a scope that corresponds to the Objective-C
89  /// \@catch statement.
90  AtCatchScope = 0x400,
91 
92  /// \brief This scope corresponds to an Objective-C method body.
93  /// It always has FnScope and DeclScope set as well.
94  ObjCMethodScope = 0x800,
95 
96  /// \brief This is a scope that corresponds to a switch statement.
97  SwitchScope = 0x1000,
98 
99  /// \brief This is the scope of a C++ try statement.
100  TryScope = 0x2000,
101 
102  /// \brief This is the scope for a function-level C++ try or catch scope.
103  FnTryCatchScope = 0x4000,
104 
105  /// \brief This is the scope of OpenMP executable directive.
106  OpenMPDirectiveScope = 0x8000,
107 
108  /// \brief This is the scope of some OpenMP loop directive.
109  OpenMPLoopDirectiveScope = 0x10000,
110 
111  /// \brief This is the scope of some OpenMP simd directive.
112  /// For example, it is used for 'omp simd', 'omp for simd'.
113  /// This flag is propagated to children scopes.
114  OpenMPSimdDirectiveScope = 0x20000,
115 
116  /// This scope corresponds to an enum.
117  EnumScope = 0x40000,
118 
119  /// This scope corresponds to an SEH try.
120  SEHTryScope = 0x80000,
121 
122  /// This scope corresponds to an SEH except.
123  SEHExceptScope = 0x100000,
124 
125  /// We are currently in the filter expression of an SEH except block.
126  SEHFilterScope = 0x200000,
127 
128  /// This is a compound statement scope.
129  CompoundStmtScope = 0x400000,
130 
131  /// We are between inheritance colon and the real class/struct definition scope.
132  ClassInheritanceScope = 0x800000,
133  };
134 private:
135  /// The parent scope for this scope. This is null for the translation-unit
136  /// scope.
137  Scope *AnyParent;
138 
139  /// Flags - This contains a set of ScopeFlags, which indicates how the scope
140  /// interrelates with other control flow statements.
141  unsigned Flags;
142 
143  /// Depth - This is the depth of this scope. The translation-unit scope has
144  /// depth 0.
145  unsigned short Depth;
146 
147  /// \brief Declarations with static linkage are mangled with the number of
148  /// scopes seen as a component.
149  unsigned short MSLastManglingNumber;
150 
151  unsigned short MSCurManglingNumber;
152 
153  /// PrototypeDepth - This is the number of function prototype scopes
154  /// enclosing this scope, including this scope.
155  unsigned short PrototypeDepth;
156 
157  /// PrototypeIndex - This is the number of parameters currently
158  /// declared in this scope.
159  unsigned short PrototypeIndex;
160 
161  /// FnParent - If this scope has a parent scope that is a function body, this
162  /// pointer is non-null and points to it. This is used for label processing.
163  Scope *FnParent;
164  Scope *MSLastManglingParent;
165 
166  /// BreakParent/ContinueParent - This is a direct link to the innermost
167  /// BreakScope/ContinueScope which contains the contents of this scope
168  /// for control flow purposes (and might be this scope itself), or null
169  /// if there is no such scope.
170  Scope *BreakParent, *ContinueParent;
171 
172  /// BlockParent - This is a direct link to the immediately containing
173  /// BlockScope if this scope is not one, or null if there is none.
174  Scope *BlockParent;
175 
176  /// TemplateParamParent - This is a direct link to the
177  /// immediately containing template parameter scope. In the
178  /// case of nested templates, template parameter scopes can have
179  /// other template parameter scopes as parents.
180  Scope *TemplateParamParent;
181 
182  /// DeclsInScope - This keeps track of all declarations in this scope. When
183  /// the declaration is added to the scope, it is set as the current
184  /// declaration for the identifier in the IdentifierTable. When the scope is
185  /// popped, these declarations are removed from the IdentifierTable's notion
186  /// of current declaration. It is up to the current Action implementation to
187  /// implement these semantics.
188  typedef llvm::SmallPtrSet<Decl *, 32> DeclSetTy;
189  DeclSetTy DeclsInScope;
190 
191  /// The DeclContext with which this scope is associated. For
192  /// example, the entity of a class scope is the class itself, the
193  /// entity of a function scope is a function, etc.
194  DeclContext *Entity;
195 
197  UsingDirectivesTy UsingDirectives;
198 
199  /// \brief Used to determine if errors occurred in this scope.
200  DiagnosticErrorTrap ErrorTrap;
201 
202  /// A lattice consisting of undefined, a single NRVO candidate variable in
203  /// this scope, or over-defined. The bit is true when over-defined.
204  llvm::PointerIntPair<VarDecl *, 1, bool> NRVO;
205 
206  void setFlags(Scope *Parent, unsigned F);
207 
208 public:
210  : ErrorTrap(Diag) {
211  Init(Parent, ScopeFlags);
212  }
213 
214  /// getFlags - Return the flags for this scope.
215  ///
216  unsigned getFlags() const { return Flags; }
217  void setFlags(unsigned F) { setFlags(getParent(), F); }
218 
219  /// isBlockScope - Return true if this scope correspond to a closure.
220  bool isBlockScope() const { return Flags & BlockScope; }
221 
222  /// getParent - Return the scope that this is nested in.
223  ///
224  const Scope *getParent() const { return AnyParent; }
225  Scope *getParent() { return AnyParent; }
226 
227  /// getFnParent - Return the closest scope that is a function body.
228  ///
229  const Scope *getFnParent() const { return FnParent; }
230  Scope *getFnParent() { return FnParent; }
231 
233  return MSLastManglingParent;
234  }
235  Scope *getMSLastManglingParent() { return MSLastManglingParent; }
236 
237  /// getContinueParent - Return the closest scope that a continue statement
238  /// would be affected by.
240  return ContinueParent;
241  }
242 
243  const Scope *getContinueParent() const {
244  return const_cast<Scope*>(this)->getContinueParent();
245  }
246 
247  /// getBreakParent - Return the closest scope that a break statement
248  /// would be affected by.
250  return BreakParent;
251  }
252  const Scope *getBreakParent() const {
253  return const_cast<Scope*>(this)->getBreakParent();
254  }
255 
256  Scope *getBlockParent() { return BlockParent; }
257  const Scope *getBlockParent() const { return BlockParent; }
258 
259  Scope *getTemplateParamParent() { return TemplateParamParent; }
260  const Scope *getTemplateParamParent() const { return TemplateParamParent; }
261 
262  /// Returns the number of function prototype scopes in this scope
263  /// chain.
264  unsigned getFunctionPrototypeDepth() const {
265  return PrototypeDepth;
266  }
267 
268  /// Return the number of parameters declared in this function
269  /// prototype, increasing it by one for the next call.
271  assert(isFunctionPrototypeScope());
272  return PrototypeIndex++;
273  }
274 
275  typedef llvm::iterator_range<DeclSetTy::iterator> decl_range;
276  decl_range decls() const {
277  return decl_range(DeclsInScope.begin(), DeclsInScope.end());
278  }
279  bool decl_empty() const { return DeclsInScope.empty(); }
280 
281  void AddDecl(Decl *D) {
282  DeclsInScope.insert(D);
283  }
284 
285  void RemoveDecl(Decl *D) {
286  DeclsInScope.erase(D);
287  }
288 
290  if (Scope *MSLMP = getMSLastManglingParent()) {
291  MSLMP->MSLastManglingNumber += 1;
292  MSCurManglingNumber += 1;
293  }
294  }
295 
297  if (Scope *MSLMP = getMSLastManglingParent()) {
298  MSLMP->MSLastManglingNumber -= 1;
299  MSCurManglingNumber -= 1;
300  }
301  }
302 
303  unsigned getMSLastManglingNumber() const {
304  if (const Scope *MSLMP = getMSLastManglingParent())
305  return MSLMP->MSLastManglingNumber;
306  return 1;
307  }
308 
309  unsigned getMSCurManglingNumber() const {
310  return MSCurManglingNumber;
311  }
312 
313  /// isDeclScope - Return true if this is the scope that the specified decl is
314  /// declared in.
315  bool isDeclScope(Decl *D) {
316  return DeclsInScope.count(D) != 0;
317  }
318 
319  DeclContext *getEntity() const { return Entity; }
320  void setEntity(DeclContext *E) { Entity = E; }
321 
322  bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); }
323 
325  return ErrorTrap.hasUnrecoverableErrorOccurred();
326  }
327 
328  /// isFunctionScope() - Return true if this scope is a function scope.
329  bool isFunctionScope() const { return (getFlags() & Scope::FnScope); }
330 
331  /// isClassScope - Return true if this scope is a class/struct/union scope.
332  bool isClassScope() const {
333  return (getFlags() & Scope::ClassScope);
334  }
335 
336  /// isInCXXInlineMethodScope - Return true if this scope is a C++ inline
337  /// method scope or is inside one.
339  if (const Scope *FnS = getFnParent()) {
340  assert(FnS->getParent() && "TUScope not created?");
341  return FnS->getParent()->isClassScope();
342  }
343  return false;
344  }
345 
346  /// isInObjcMethodScope - Return true if this scope is, or is contained in, an
347  /// Objective-C method body. Note that this method is not constant time.
348  bool isInObjcMethodScope() const {
349  for (const Scope *S = this; S; S = S->getParent()) {
350  // If this scope is an objc method scope, then we succeed.
351  if (S->getFlags() & ObjCMethodScope)
352  return true;
353  }
354  return false;
355  }
356 
357  /// isInObjcMethodOuterScope - Return true if this scope is an
358  /// Objective-C method outer most body.
360  if (const Scope *S = this) {
361  // If this scope is an objc method scope, then we succeed.
362  if (S->getFlags() & ObjCMethodScope)
363  return true;
364  }
365  return false;
366  }
367 
368 
369  /// isTemplateParamScope - Return true if this scope is a C++
370  /// template parameter scope.
371  bool isTemplateParamScope() const {
372  return getFlags() & Scope::TemplateParamScope;
373  }
374 
375  /// isFunctionPrototypeScope - Return true if this scope is a
376  /// function prototype scope.
378  return getFlags() & Scope::FunctionPrototypeScope;
379  }
380 
381  /// isAtCatchScope - Return true if this scope is \@catch.
382  bool isAtCatchScope() const {
383  return getFlags() & Scope::AtCatchScope;
384  }
385 
386  /// isSwitchScope - Return true if this scope is a switch scope.
387  bool isSwitchScope() const {
388  for (const Scope *S = this; S; S = S->getParent()) {
389  if (S->getFlags() & Scope::SwitchScope)
390  return true;
391  else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope |
392  Scope::BlockScope | Scope::TemplateParamScope |
393  Scope::FunctionPrototypeScope |
394  Scope::AtCatchScope | Scope::ObjCMethodScope))
395  return false;
396  }
397  return false;
398  }
399 
400  /// \brief Determines whether this scope is the OpenMP directive scope
401  bool isOpenMPDirectiveScope() const {
402  return (getFlags() & Scope::OpenMPDirectiveScope);
403  }
404 
405  /// \brief Determine whether this scope is some OpenMP loop directive scope
406  /// (for example, 'omp for', 'omp simd').
408  if (getFlags() & Scope::OpenMPLoopDirectiveScope) {
409  assert(isOpenMPDirectiveScope() &&
410  "OpenMP loop directive scope is not a directive scope");
411  return true;
412  }
413  return false;
414  }
415 
416  /// \brief Determine whether this scope is (or is nested into) some OpenMP
417  /// loop simd directive scope (for example, 'omp simd', 'omp for simd').
419  return getFlags() & Scope::OpenMPSimdDirectiveScope;
420  }
421 
422  /// \brief Determine whether this scope is a loop having OpenMP loop
423  /// directive attached.
424  bool isOpenMPLoopScope() const {
425  const Scope *P = getParent();
426  return P && P->isOpenMPLoopDirectiveScope();
427  }
428 
429  /// \brief Determine whether this scope is a C++ 'try' block.
430  bool isTryScope() const { return getFlags() & Scope::TryScope; }
431 
432  /// \brief Determine whether this scope is a SEH '__try' block.
433  bool isSEHTryScope() const { return getFlags() & Scope::SEHTryScope; }
434 
435  /// \brief Determine whether this scope is a SEH '__except' block.
436  bool isSEHExceptScope() const { return getFlags() & Scope::SEHExceptScope; }
437 
438  /// \brief Determine whether this scope is a compound statement scope.
439  bool isCompoundStmtScope() const {
440  return getFlags() & Scope::CompoundStmtScope;
441  }
442 
443  /// \brief Returns if rhs has a higher scope depth than this.
444  ///
445  /// The caller is responsible for calling this only if one of the two scopes
446  /// is an ancestor of the other.
447  bool Contains(const Scope& rhs) const { return Depth < rhs.Depth; }
448 
449  /// containedInPrototypeScope - Return true if this or a parent scope
450  /// is a FunctionPrototypeScope.
451  bool containedInPrototypeScope() const;
452 
454  UsingDirectives.push_back(UDir);
455  }
456 
457  typedef llvm::iterator_range<UsingDirectivesTy::iterator>
459 
461  return using_directives_range(UsingDirectives.begin(),
462  UsingDirectives.end());
463  }
464 
466  if (NRVO.getInt())
467  return;
468  if (NRVO.getPointer() == nullptr) {
469  NRVO.setPointer(VD);
470  return;
471  }
472  if (NRVO.getPointer() != VD)
473  setNoNRVO();
474  }
475 
476  void setNoNRVO() {
477  NRVO.setInt(1);
478  NRVO.setPointer(nullptr);
479  }
480 
481  void mergeNRVOIntoParent();
482 
483  /// Init - This is used by the parser to implement scope caching.
484  ///
485  void Init(Scope *parent, unsigned flags);
486 
487  /// \brief Sets up the specified scope flags and adjusts the scope state
488  /// variables accordingly.
489  ///
490  void AddFlags(unsigned Flags);
491 
492  void dumpImpl(raw_ostream &OS) const;
493  void dump() const;
494 };
495 
496 } // end namespace clang
497 
498 #endif
Scope * getFnParent()
Definition: Scope.h:230
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
DominatorTree GraphTraits specialization so the DominatorTree can be iterable by generic graph iterat...
Definition: Dominators.h:26
const Scope * getTemplateParamParent() const
Definition: Scope.h:260
bool isBlockScope() const
isBlockScope - Return true if this scope correspond to a closure.
Definition: Scope.h:220
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
Scope * getBlockParent()
Definition: Scope.h:256
void setFlags(unsigned F)
Definition: Scope.h:217
StringRef P
bool isTemplateParamScope() const
isTemplateParamScope - Return true if this scope is a C++ template parameter scope.
Definition: Scope.h:371
void AddDecl(Decl *D)
Definition: Scope.h:281
The l-value was an access to a declared entity or something equivalently strong, like the address of ...
Scope * getContinueParent()
getContinueParent - Return the closest scope that a continue statement would be affected by...
Definition: Scope.h:239
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:807
ScopeFlags
ScopeFlags - These are bitfields that are or&#39;d together when creating a scope, which defines the sort...
Definition: Scope.h:43
bool isInObjcMethodScope() const
isInObjcMethodScope - Return true if this scope is, or is contained in, an Objective-C method body...
Definition: Scope.h:348
RAII class that determines when any errors have occurred between the time the instance was created an...
Definition: Diagnostic.h:911
Scope(Scope *Parent, unsigned ScopeFlags, DiagnosticsEngine &Diag)
Definition: Scope.h:209
Scope * getTemplateParamParent()
Definition: Scope.h:259
bool isAtCatchScope() const
isAtCatchScope - Return true if this scope is @catch.
Definition: Scope.h:382
unsigned getFunctionPrototypeDepth() const
Returns the number of function prototype scopes in this scope chain.
Definition: Scope.h:264
void decrementMSManglingNumber()
Definition: Scope.h:296
void setNoNRVO()
Definition: Scope.h:476
Scope * getBreakParent()
getBreakParent - Return the closest scope that a break statement would be affected by...
Definition: Scope.h:249
bool isFunctionPrototypeScope() const
isFunctionPrototypeScope - Return true if this scope is a function prototype scope.
Definition: Scope.h:377
static void dump(llvm::raw_ostream &OS, StringRef FunctionName, ArrayRef< CounterExpression > Expressions, ArrayRef< CounterMappingRegion > Regions)
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:147
bool isFunctionScope() const
isFunctionScope() - Return true if this scope is a function scope.
Definition: Scope.h:329
unsigned getMSLastManglingNumber() const
Definition: Scope.h:303
Defines the Diagnostic-related interfaces.
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:39
using_directives_range using_directives()
Definition: Scope.h:460
void incrementMSManglingNumber()
Definition: Scope.h:289
NodeId Parent
Definition: ASTDiff.cpp:192
unsigned getFlags() const
getFlags - Return the flags for this scope.
Definition: Scope.h:216
bool decl_empty() const
Definition: Scope.h:279
llvm::iterator_range< DeclSetTy::iterator > decl_range
Definition: Scope.h:275
bool isInCXXInlineMethodScope() const
isInCXXInlineMethodScope - Return true if this scope is a C++ inline method scope or is inside one...
Definition: Scope.h:338
bool isInObjcMethodOuterScope() const
isInObjcMethodOuterScope - Return true if this scope is an Objective-C method outer most body...
Definition: Scope.h:359
bool isDeclScope(Decl *D)
isDeclScope - Return true if this is the scope that the specified decl is declared in...
Definition: Scope.h:315
DeclContext * getEntity() const
Definition: Scope.h:319
Scope * getMSLastManglingParent()
Definition: Scope.h:235
bool isSEHTryScope() const
Determine whether this scope is a SEH &#39;__try&#39; block.
Definition: Scope.h:433
int Depth
Definition: ASTDiff.cpp:191
bool isClassScope() const
isClassScope - Return true if this scope is a class/struct/union scope.
Definition: Scope.h:332
decl_range decls() const
Definition: Scope.h:276
bool hasErrorOccurred() const
Definition: Scope.h:322
bool isCompoundStmtScope() const
Determine whether this scope is a compound statement scope.
Definition: Scope.h:439
bool Contains(const Scope &rhs) const
Returns if rhs has a higher scope depth than this.
Definition: Scope.h:447
unsigned getMSCurManglingNumber() const
Definition: Scope.h:309
bool isOpenMPLoopScope() const
Determine whether this scope is a loop having OpenMP loop directive attached.
Definition: Scope.h:424
const Scope * getBreakParent() const
Definition: Scope.h:252
bool hasErrorOccurred() const
Determine whether any errors have occurred since this object instance was created.
Definition: Diagnostic.h:922
Scope * getParent()
Definition: Scope.h:225
void setEntity(DeclContext *E)
Definition: Scope.h:320
const Scope * getContinueParent() const
Definition: Scope.h:243
bool isOpenMPDirectiveScope() const
Determines whether this scope is the OpenMP directive scope.
Definition: Scope.h:401
Dataflow Directional Tag Classes.
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1252
const Scope * getParent() const
getParent - Return the scope that this is nested in.
Definition: Scope.h:224
bool isSEHExceptScope() const
Determine whether this scope is a SEH &#39;__except&#39; block.
Definition: Scope.h:436
void addNRVOCandidate(VarDecl *VD)
Definition: Scope.h:465
unsigned getNextFunctionPrototypeIndex()
Return the number of parameters declared in this function prototype, increasing it by one for the nex...
Definition: Scope.h:270
bool hasUnrecoverableErrorOccurred() const
Determine whether any unrecoverable errors have occurred since this object instance was created...
Definition: Diagnostic.h:928
llvm::iterator_range< UsingDirectivesTy::iterator > using_directives_range
Definition: Scope.h:458
void PushUsingDirective(UsingDirectiveDecl *UDir)
Definition: Scope.h:453
void RemoveDecl(Decl *D)
Definition: Scope.h:285
bool isOpenMPLoopDirectiveScope() const
Determine whether this scope is some OpenMP loop directive scope (for example, &#39;omp for&#39;...
Definition: Scope.h:407
const Scope * getMSLastManglingParent() const
Definition: Scope.h:232
bool isOpenMPSimdDirectiveScope() const
Determine whether this scope is (or is nested into) some OpenMP loop simd directive scope (for exampl...
Definition: Scope.h:418
bool isSwitchScope() const
isSwitchScope - Return true if this scope is a switch scope.
Definition: Scope.h:387
const Scope * getFnParent() const
getFnParent - Return the closest scope that is a function body.
Definition: Scope.h:229
bool isTryScope() const
Determine whether this scope is a C++ &#39;try&#39; block.
Definition: Scope.h:430
bool hasUnrecoverableErrorOccurred() const
Definition: Scope.h:324
Represents C++ using-directive.
Definition: DeclCXX.h:2843
const Scope * getBlockParent() const
Definition: Scope.h:257