DelayedDiagnostic.h revision d7a3e2c5f61cd4893f95b69a424fe4def3aa0f69 
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/AST/DeclCXX.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(ASTContext &Context,
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, Context.getDiagAllocator()) {
51  }
52
53  AccessedEntity(ASTContext &Context,
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, Context.getDiagAllocator()) {
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                                           StringRef Msg);
127
128  static DelayedDiagnostic makeAccess(SourceLocation Loc,
129                                      const AccessedEntity &Entity) {
130    DelayedDiagnostic DD;
131    DD.Kind = Access;
132    DD.Triggered = false;
133    DD.Loc = Loc;
134    new (&DD.getAccessData()) AccessedEntity(Entity);
135    return DD;
136  }
137
138  static DelayedDiagnostic makeForbiddenType(SourceLocation loc,
139                                             unsigned diagnostic,
140                                             QualType type,
141                                             unsigned argument) {
142    DelayedDiagnostic DD;
143    DD.Kind = ForbiddenType;
144    DD.Triggered = false;
145    DD.Loc = loc;
146    DD.ForbiddenTypeData.Diagnostic = diagnostic;
147    DD.ForbiddenTypeData.OperandType = type.getAsOpaquePtr();
148    DD.ForbiddenTypeData.Argument = argument;
149    return DD;
150  }
151
152  AccessedEntity &getAccessData() {
153    assert(Kind == Access && "Not an access diagnostic.");
154    return *reinterpret_cast<AccessedEntity*>(AccessData);
155  }
156  const AccessedEntity &getAccessData() const {
157    assert(Kind == Access && "Not an access diagnostic.");
158    return *reinterpret_cast<const AccessedEntity*>(AccessData);
159  }
160
161  const NamedDecl *getDeprecationDecl() const {
162    assert(Kind == Deprecation && "Not a deprecation diagnostic.");
163    return DeprecationData.Decl;
164  }
165
166  StringRef getDeprecationMessage() const {
167    assert(Kind == Deprecation && "Not a deprecation diagnostic.");
168    return StringRef(DeprecationData.Message,
169                           DeprecationData.MessageLen);
170  }
171
172  /// The diagnostic ID to emit.  Used like so:
173  ///   Diag(diag.Loc, diag.getForbiddenTypeDiagnostic())
174  ///     << diag.getForbiddenTypeOperand()
175  ///     << diag.getForbiddenTypeArgument();
176  unsigned getForbiddenTypeDiagnostic() const {
177    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
178    return ForbiddenTypeData.Diagnostic;
179  }
180
181  unsigned getForbiddenTypeArgument() const {
182    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
183    return ForbiddenTypeData.Argument;
184  }
185
186  QualType getForbiddenTypeOperand() const {
187    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
188    return QualType::getFromOpaquePtr(ForbiddenTypeData.OperandType);
189  }
190
191private:
192  union {
193    /// Deprecation.
194    struct {
195      const NamedDecl *Decl;
196      const char *Message;
197      size_t MessageLen;
198    } DeprecationData;
199
200    struct {
201      unsigned Diagnostic;
202      unsigned Argument;
203      void *OperandType;
204    } ForbiddenTypeData;
205
206    /// Access control.
207    char AccessData[sizeof(AccessedEntity)];
208  };
209};
210
211}
212}
213
214#endif
215