DelayedDiagnostic.h revision 00bd44d5677783527d7517c1ffe45e4d75a0f56f 
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#include "clang/Basic/PartialDiagnostic.h"
26
27namespace clang {
28namespace sema {
29
30/// A declaration being accessed, together with information about how
31/// it was accessed.
32class AccessedEntity {
33public:
34  /// A member declaration found through lookup.  The target is the
35  /// member.
36  enum MemberNonce { Member };
37
38  /// A hierarchy (base-to-derived or derived-to-base) conversion.
39  /// The target is the base class.
40  enum BaseNonce { Base };
41
42  bool isMemberAccess() const { return IsMember; }
43
44  AccessedEntity(ASTContext &Context,
45                 MemberNonce _,
46                 CXXRecordDecl *NamingClass,
47                 DeclAccessPair FoundDecl,
48                 QualType BaseObjectType)
49    : Access(FoundDecl.getAccess()), IsMember(true),
50      Target(FoundDecl.getDecl()), NamingClass(NamingClass),
51      BaseObjectType(BaseObjectType), Diag(0, Context.getDiagAllocator()) {
52  }
53
54  AccessedEntity(ASTContext &Context,
55                 BaseNonce _,
56                 CXXRecordDecl *BaseClass,
57                 CXXRecordDecl *DerivedClass,
58                 AccessSpecifier Access)
59    : Access(Access), IsMember(false),
60      Target(BaseClass),
61      NamingClass(DerivedClass),
62      Diag(0, Context.getDiagAllocator()) {
63  }
64
65  bool isQuiet() const { return Diag.getDiagID() == 0; }
66
67  AccessSpecifier getAccess() const { return AccessSpecifier(Access); }
68
69  // These apply to member decls...
70  NamedDecl *getTargetDecl() const { return Target; }
71  CXXRecordDecl *getNamingClass() const { return NamingClass; }
72
73  // ...and these apply to hierarchy conversions.
74  CXXRecordDecl *getBaseClass() const {
75    assert(!IsMember); return cast<CXXRecordDecl>(Target);
76  }
77  CXXRecordDecl *getDerivedClass() const { return NamingClass; }
78
79  /// Retrieves the base object type, important when accessing
80  /// an instance member.
81  QualType getBaseObjectType() const { return BaseObjectType; }
82
83  /// Sets a diagnostic to be performed.  The diagnostic is given
84  /// four (additional) arguments:
85  ///   %0 - 0 if the entity was private, 1 if protected
86  ///   %1 - the DeclarationName of the entity
87  ///   %2 - the TypeDecl type of the naming class
88  ///   %3 - the TypeDecl type of the declaring class
89  void setDiag(const PartialDiagnostic &PDiag) {
90    assert(isQuiet() && "partial diagnostic already defined");
91    Diag = PDiag;
92  }
93  PartialDiagnostic &setDiag(unsigned DiagID) {
94    assert(isQuiet() && "partial diagnostic already defined");
95    assert(DiagID && "creating null diagnostic");
96    Diag.Reset(DiagID);
97    return Diag;
98  }
99  const PartialDiagnostic &getDiag() const {
100    return Diag;
101  }
102
103private:
104  unsigned Access : 2;
105  unsigned IsMember : 1;
106  NamedDecl *Target;
107  CXXRecordDecl *NamingClass;
108  QualType BaseObjectType;
109  PartialDiagnostic Diag;
110};
111
112/// A diagnostic message which has been conditionally emitted pending
113/// the complete parsing of the current declaration.
114class DelayedDiagnostic {
115public:
116  enum DDKind { Deprecation, Access, ForbiddenType };
117
118  unsigned char Kind; // actually a DDKind
119  bool Triggered;
120
121  SourceLocation Loc;
122
123  void Destroy();
124
125  static DelayedDiagnostic makeDeprecation(SourceLocation Loc,
126                                           const NamedDecl *D,
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
192private:
193  union {
194    /// Deprecation.
195    struct {
196      const NamedDecl *Decl;
197      const char *Message;
198      size_t MessageLen;
199    } DeprecationData;
200
201    struct {
202      unsigned Diagnostic;
203      unsigned Argument;
204      void *OperandType;
205    } ForbiddenTypeData;
206
207    /// Access control.
208    char AccessData[sizeof(AccessedEntity)];
209  };
210};
211
212}
213}
214
215#endif
216