DelayedDiagnostic.h revision 478851c3ed6bd784e7377dffd8e57b200c1b9ba9 
1//===--- DelayedDiagnostic.h - Delayed declarator diagnostics ---*- 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 DelayedDiagnostic class, which is used to
11// record diagnostics that are being conditionally produced during
12// declarator parsing.  Certain kinds of diagnostics --- notably
13// deprecation and access control --- are suppressed based on
14// semantic properties of the parsed declaration that aren't known
15// until it is fully parsed.
16//
17// This file also defines AccessedEntity.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_CLANG_SEMA_DELAYED_DIAGNOSTIC_H
22#define LLVM_CLANG_SEMA_DELAYED_DIAGNOSTIC_H
23
24#include "clang/Sema/Sema.h"
25
26namespace clang {
27namespace sema {
28
29/// A declaration being accessed, together with information about how
30/// it was accessed.
31class AccessedEntity {
32public:
33  /// A member declaration found through lookup.  The target is the
34  /// member.
35  enum MemberNonce { Member };
36
37  /// A hierarchy (base-to-derived or derived-to-base) conversion.
38  /// The target is the base class.
39  enum BaseNonce { Base };
40
41  bool isMemberAccess() const { return IsMember; }
42
43  AccessedEntity(PartialDiagnostic::StorageAllocator &Allocator,
44                 MemberNonce _,
45                 CXXRecordDecl *NamingClass,
46                 DeclAccessPair FoundDecl,
47                 QualType BaseObjectType)
48    : Access(FoundDecl.getAccess()), IsMember(true),
49      Target(FoundDecl.getDecl()), NamingClass(NamingClass),
50      BaseObjectType(BaseObjectType), Diag(0, Allocator) {
51  }
52
53  AccessedEntity(PartialDiagnostic::StorageAllocator &Allocator,
54                 BaseNonce _,
55                 CXXRecordDecl *BaseClass,
56                 CXXRecordDecl *DerivedClass,
57                 AccessSpecifier Access)
58    : Access(Access), IsMember(false),
59      Target(BaseClass),
60      NamingClass(DerivedClass),
61      Diag(0, Allocator) {
62  }
63
64  bool isQuiet() const { return Diag.getDiagID() == 0; }
65
66  AccessSpecifier getAccess() const { return AccessSpecifier(Access); }
67
68  // These apply to member decls...
69  NamedDecl *getTargetDecl() const { return Target; }
70  CXXRecordDecl *getNamingClass() const { return NamingClass; }
71
72  // ...and these apply to hierarchy conversions.
73  CXXRecordDecl *getBaseClass() const {
74    assert(!IsMember); return cast<CXXRecordDecl>(Target);
75  }
76  CXXRecordDecl *getDerivedClass() const { return NamingClass; }
77
78  /// Retrieves the base object type, important when accessing
79  /// an instance member.
80  QualType getBaseObjectType() const { return BaseObjectType; }
81
82  /// Sets a diagnostic to be performed.  The diagnostic is given
83  /// four (additional) arguments:
84  ///   %0 - 0 if the entity was private, 1 if protected
85  ///   %1 - the DeclarationName of the entity
86  ///   %2 - the TypeDecl type of the naming class
87  ///   %3 - the TypeDecl type of the declaring class
88  void setDiag(const PartialDiagnostic &PDiag) {
89    assert(isQuiet() && "partial diagnostic already defined");
90    Diag = PDiag;
91  }
92  PartialDiagnostic &setDiag(unsigned DiagID) {
93    assert(isQuiet() && "partial diagnostic already defined");
94    assert(DiagID && "creating null diagnostic");
95    Diag.Reset(DiagID);
96    return Diag;
97  }
98  const PartialDiagnostic &getDiag() const {
99    return Diag;
100  }
101
102private:
103  unsigned Access : 2;
104  unsigned IsMember : 1;
105  NamedDecl *Target;
106  CXXRecordDecl *NamingClass;
107  QualType BaseObjectType;
108  PartialDiagnostic Diag;
109};
110
111/// A diagnostic message which has been conditionally emitted pending
112/// the complete parsing of the current declaration.
113class DelayedDiagnostic {
114public:
115  enum DDKind { Deprecation, Access, ForbiddenType };
116
117  unsigned char Kind; // actually a DDKind
118  bool Triggered;
119
120  SourceLocation Loc;
121
122  void Destroy();
123
124  static DelayedDiagnostic makeDeprecation(SourceLocation Loc,
125           const NamedDecl *D,
126           const ObjCInterfaceDecl *UnknownObjCClass,
127           StringRef Msg);
128
129  static DelayedDiagnostic makeAccess(SourceLocation Loc,
130                                      const AccessedEntity &Entity) {
131    DelayedDiagnostic DD;
132    DD.Kind = Access;
133    DD.Triggered = false;
134    DD.Loc = Loc;
135    new (&DD.getAccessData()) AccessedEntity(Entity);
136    return DD;
137  }
138
139  static DelayedDiagnostic makeForbiddenType(SourceLocation loc,
140                                             unsigned diagnostic,
141                                             QualType type,
142                                             unsigned argument) {
143    DelayedDiagnostic DD;
144    DD.Kind = ForbiddenType;
145    DD.Triggered = false;
146    DD.Loc = loc;
147    DD.ForbiddenTypeData.Diagnostic = diagnostic;
148    DD.ForbiddenTypeData.OperandType = type.getAsOpaquePtr();
149    DD.ForbiddenTypeData.Argument = argument;
150    return DD;
151  }
152
153  AccessedEntity &getAccessData() {
154    assert(Kind == Access && "Not an access diagnostic.");
155    return *reinterpret_cast<AccessedEntity*>(AccessData);
156  }
157  const AccessedEntity &getAccessData() const {
158    assert(Kind == Access && "Not an access diagnostic.");
159    return *reinterpret_cast<const AccessedEntity*>(AccessData);
160  }
161
162  const NamedDecl *getDeprecationDecl() const {
163    assert(Kind == Deprecation && "Not a deprecation diagnostic.");
164    return DeprecationData.Decl;
165  }
166
167  StringRef getDeprecationMessage() const {
168    assert(Kind == Deprecation && "Not a deprecation diagnostic.");
169    return StringRef(DeprecationData.Message,
170                           DeprecationData.MessageLen);
171  }
172
173  /// The diagnostic ID to emit.  Used like so:
174  ///   Diag(diag.Loc, diag.getForbiddenTypeDiagnostic())
175  ///     << diag.getForbiddenTypeOperand()
176  ///     << diag.getForbiddenTypeArgument();
177  unsigned getForbiddenTypeDiagnostic() const {
178    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
179    return ForbiddenTypeData.Diagnostic;
180  }
181
182  unsigned getForbiddenTypeArgument() const {
183    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
184    return ForbiddenTypeData.Argument;
185  }
186
187  QualType getForbiddenTypeOperand() const {
188    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
189    return QualType::getFromOpaquePtr(ForbiddenTypeData.OperandType);
190  }
191
192  const ObjCInterfaceDecl *getUnknownObjCClass() const {
193    return DeprecationData.UnknownObjCClass;
194  }
195
196private:
197  union {
198    /// Deprecation.
199    struct {
200      const NamedDecl *Decl;
201      const ObjCInterfaceDecl *UnknownObjCClass;
202      const char *Message;
203      size_t MessageLen;
204    } DeprecationData;
205
206    struct {
207      unsigned Diagnostic;
208      unsigned Argument;
209      void *OperandType;
210    } ForbiddenTypeData;
211
212    /// Access control.
213    char AccessData[sizeof(AccessedEntity)];
214  };
215};
216
217/// DelayedDiagnosticPool - A collection of diagnostics which were
218/// delayed.
219class DelayedDiagnosticPool {
220  const DelayedDiagnosticPool *Parent;
221  llvm::SmallVector<DelayedDiagnostic, 4> Diagnostics;
222
223  // Do not implement.
224  DelayedDiagnosticPool(const DelayedDiagnosticPool &other);
225  DelayedDiagnosticPool &operator=(const DelayedDiagnosticPool &other);
226public:
227  DelayedDiagnosticPool(const DelayedDiagnosticPool *parent) : Parent(parent) {}
228  ~DelayedDiagnosticPool() {
229    for (llvm::SmallVectorImpl<DelayedDiagnostic>::iterator
230           i = Diagnostics.begin(), e = Diagnostics.end(); i != e; ++i)
231      i->Destroy();
232  }
233
234  const DelayedDiagnosticPool *getParent() const { return Parent; }
235
236  /// Does this pool, or any of its ancestors, contain any diagnostics?
237  bool empty() const {
238    return (Diagnostics.empty() && (Parent == NULL || Parent->empty()));
239  }
240
241  /// Add a diagnostic to this pool.
242  void add(const DelayedDiagnostic &diag) {
243    Diagnostics.push_back(diag);
244  }
245
246  /// Steal the diagnostics from the given pool.
247  void steal(DelayedDiagnosticPool &pool) {
248    if (pool.Diagnostics.empty()) return;
249
250    if (Diagnostics.empty()) {
251      Diagnostics = llvm_move(pool.Diagnostics);
252    } else {
253      Diagnostics.append(pool.pool_begin(), pool.pool_end());
254    }
255    pool.Diagnostics.clear();
256  }
257
258  typedef llvm::SmallVectorImpl<DelayedDiagnostic>::const_iterator
259    pool_iterator;
260  pool_iterator pool_begin() const { return Diagnostics.begin(); }
261  pool_iterator pool_end() const { return Diagnostics.end(); }
262  bool pool_empty() const { return Diagnostics.empty(); }
263};
264
265}
266
267/// Add a diagnostic to the current delay pool.
268inline void Sema::DelayedDiagnostics::add(const sema::DelayedDiagnostic &diag) {
269  assert(shouldDelayDiagnostics() && "trying to delay without pool");
270  CurPool->add(diag);
271}
272
273
274}
275
276#endif
277