1//===- DelayedDiagnostic.h - Delayed declarator diagnostics -----*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// Defines the classes clang::DelayedDiagnostic and
11/// clang::AccessedEntity.
12///
13/// DelayedDiangostic is used to record diagnostics that are being
14/// conditionally produced during declarator parsing.  Certain kinds of
15/// diagnostics -- notably deprecation and access control -- are suppressed
16/// based on semantic properties of the parsed declaration that aren't known
17/// until it is fully parsed.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_CLANG_SEMA_DELAYEDDIAGNOSTIC_H
22#define LLVM_CLANG_SEMA_DELAYEDDIAGNOSTIC_H
23
24#include "clang/AST/DeclAccessPair.h"
25#include "clang/AST/DeclBase.h"
26#include "clang/AST/DeclCXX.h"
27#include "clang/AST/Type.h"
28#include "clang/Basic/LLVM.h"
29#include "clang/Basic/PartialDiagnostic.h"
30#include "clang/Basic/SourceLocation.h"
31#include "clang/Basic/Specifiers.h"
32#include "clang/Sema/Sema.h"
33#include "llvm/ADT/ArrayRef.h"
34#include "llvm/ADT/SmallVector.h"
35#include "llvm/ADT/StringRef.h"
36#include "llvm/Support/Casting.h"
37#include <cassert>
38#include <cstddef>
39#include <utility>
40
41namespace clang {
42
43class ObjCInterfaceDecl;
44class ObjCPropertyDecl;
45
46namespace sema {
47
48/// A declaration being accessed, together with information about how
49/// it was accessed.
50class AccessedEntity {
51public:
52  /// A member declaration found through lookup.  The target is the
53  /// member.
54  enum MemberNonce { Member };
55
56  /// A hierarchy (base-to-derived or derived-to-base) conversion.
57  /// The target is the base class.
58  enum BaseNonce { Base };
59
60  AccessedEntity(PartialDiagnostic::DiagStorageAllocator &Allocator,
61                 MemberNonce _, CXXRecordDecl *NamingClass,
62                 DeclAccessPair FoundDecl, QualType BaseObjectType)
63      : Access(FoundDecl.getAccess()), IsMember(true),
64        Target(FoundDecl.getDecl()), NamingClass(NamingClass),
65        BaseObjectType(BaseObjectType), Diag(0, Allocator) {}
66
67  AccessedEntity(PartialDiagnostic::DiagStorageAllocator &Allocator,
68                 BaseNonce _, CXXRecordDecl *BaseClass,
69                 CXXRecordDecl *DerivedClass, AccessSpecifier Access)
70      : Access(Access), IsMember(false), Target(BaseClass),
71        NamingClass(DerivedClass), Diag(0, Allocator) {}
72
73  bool isMemberAccess() const { return IsMember; }
74
75  bool isQuiet() const { return Diag.getDiagID() == 0; }
76
77  AccessSpecifier getAccess() const { return AccessSpecifier(Access); }
78
79  // These apply to member decls...
80  NamedDecl *getTargetDecl() const { return Target; }
81  CXXRecordDecl *getNamingClass() const { return NamingClass; }
82
83  // ...and these apply to hierarchy conversions.
84  CXXRecordDecl *getBaseClass() const {
85    assert(!IsMember); return cast<CXXRecordDecl>(Target);
86  }
87  CXXRecordDecl *getDerivedClass() const { return NamingClass; }
88
89  /// Retrieves the base object type, important when accessing
90  /// an instance member.
91  QualType getBaseObjectType() const { return BaseObjectType; }
92
93  /// Sets a diagnostic to be performed.  The diagnostic is given
94  /// four (additional) arguments:
95  ///   %0 - 0 if the entity was private, 1 if protected
96  ///   %1 - the DeclarationName of the entity
97  ///   %2 - the TypeDecl type of the naming class
98  ///   %3 - the TypeDecl type of the declaring class
99  void setDiag(const PartialDiagnostic &PDiag) {
100    assert(isQuiet() && "partial diagnostic already defined");
101    Diag = PDiag;
102  }
103  PartialDiagnostic &setDiag(unsigned DiagID) {
104    assert(isQuiet() && "partial diagnostic already defined");
105    assert(DiagID && "creating null diagnostic");
106    Diag.Reset(DiagID);
107    return Diag;
108  }
109  const PartialDiagnostic &getDiag() const {
110    return Diag;
111  }
112
113private:
114  unsigned Access : 2;
115  unsigned IsMember : 1;
116  NamedDecl *Target;
117  CXXRecordDecl *NamingClass;
118  QualType BaseObjectType;
119  PartialDiagnostic Diag;
120};
121
122/// A diagnostic message which has been conditionally emitted pending
123/// the complete parsing of the current declaration.
124class DelayedDiagnostic {
125public:
126  enum DDKind : unsigned char { Availability, Access, ForbiddenType };
127
128  DDKind Kind;
129  bool Triggered;
130
131  SourceLocation Loc;
132
133  void Destroy();
134
135  static DelayedDiagnostic makeAvailability(AvailabilityResult AR,
136                                            ArrayRef<SourceLocation> Locs,
137                                            const NamedDecl *ReferringDecl,
138                                            const NamedDecl *OffendingDecl,
139                                            const ObjCInterfaceDecl *UnknownObjCClass,
140                                            const ObjCPropertyDecl  *ObjCProperty,
141                                            StringRef Msg,
142                                            bool ObjCPropertyAccess);
143
144  static DelayedDiagnostic makeAccess(SourceLocation Loc,
145                                      const AccessedEntity &Entity) {
146    DelayedDiagnostic DD;
147    DD.Kind = Access;
148    DD.Triggered = false;
149    DD.Loc = Loc;
150    new (&DD.getAccessData()) AccessedEntity(Entity);
151    return DD;
152  }
153
154  static DelayedDiagnostic makeForbiddenType(SourceLocation loc,
155                                             unsigned diagnostic,
156                                             QualType type,
157                                             unsigned argument) {
158    DelayedDiagnostic DD;
159    DD.Kind = ForbiddenType;
160    DD.Triggered = false;
161    DD.Loc = loc;
162    DD.ForbiddenTypeData.Diagnostic = diagnostic;
163    DD.ForbiddenTypeData.OperandType = type.getAsOpaquePtr();
164    DD.ForbiddenTypeData.Argument = argument;
165    return DD;
166  }
167
168  AccessedEntity &getAccessData() {
169    assert(Kind == Access && "Not an access diagnostic.");
170    return *reinterpret_cast<AccessedEntity*>(AccessData);
171  }
172  const AccessedEntity &getAccessData() const {
173    assert(Kind == Access && "Not an access diagnostic.");
174    return *reinterpret_cast<const AccessedEntity*>(AccessData);
175  }
176
177  const NamedDecl *getAvailabilityReferringDecl() const {
178    assert(Kind == Availability && "Not an availability diagnostic.");
179    return AvailabilityData.ReferringDecl;
180  }
181
182  const NamedDecl *getAvailabilityOffendingDecl() const {
183    return AvailabilityData.OffendingDecl;
184  }
185
186  StringRef getAvailabilityMessage() const {
187    assert(Kind == Availability && "Not an availability diagnostic.");
188    return StringRef(AvailabilityData.Message, AvailabilityData.MessageLen);
189  }
190
191  ArrayRef<SourceLocation> getAvailabilitySelectorLocs() const {
192    assert(Kind == Availability && "Not an availability diagnostic.");
193    return llvm::ArrayRef(AvailabilityData.SelectorLocs,
194                          AvailabilityData.NumSelectorLocs);
195  }
196
197  AvailabilityResult getAvailabilityResult() const {
198    assert(Kind == Availability && "Not an availability diagnostic.");
199    return AvailabilityData.AR;
200  }
201
202  /// The diagnostic ID to emit.  Used like so:
203  ///   Diag(diag.Loc, diag.getForbiddenTypeDiagnostic())
204  ///     << diag.getForbiddenTypeOperand()
205  ///     << diag.getForbiddenTypeArgument();
206  unsigned getForbiddenTypeDiagnostic() const {
207    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
208    return ForbiddenTypeData.Diagnostic;
209  }
210
211  unsigned getForbiddenTypeArgument() const {
212    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
213    return ForbiddenTypeData.Argument;
214  }
215
216  QualType getForbiddenTypeOperand() const {
217    assert(Kind == ForbiddenType && "not a forbidden-type diagnostic");
218    return QualType::getFromOpaquePtr(ForbiddenTypeData.OperandType);
219  }
220
221  const ObjCInterfaceDecl *getUnknownObjCClass() const {
222    return AvailabilityData.UnknownObjCClass;
223  }
224
225  const ObjCPropertyDecl *getObjCProperty() const {
226    return AvailabilityData.ObjCProperty;
227  }
228
229  bool getObjCPropertyAccess() const {
230    return AvailabilityData.ObjCPropertyAccess;
231  }
232
233private:
234  struct AD {
235    const NamedDecl *ReferringDecl;
236    const NamedDecl *OffendingDecl;
237    const ObjCInterfaceDecl *UnknownObjCClass;
238    const ObjCPropertyDecl  *ObjCProperty;
239    const char *Message;
240    size_t MessageLen;
241    SourceLocation *SelectorLocs;
242    size_t NumSelectorLocs;
243    AvailabilityResult AR;
244    bool ObjCPropertyAccess;
245  };
246
247  struct FTD {
248    unsigned Diagnostic;
249    unsigned Argument;
250    void *OperandType;
251  };
252
253  union {
254    struct AD AvailabilityData;
255    struct FTD ForbiddenTypeData;
256
257    /// Access control.
258    char AccessData[sizeof(AccessedEntity)];
259  };
260};
261
262/// A collection of diagnostics which were delayed.
263class DelayedDiagnosticPool {
264  const DelayedDiagnosticPool *Parent;
265  SmallVector<DelayedDiagnostic, 4> Diagnostics;
266
267public:
268  DelayedDiagnosticPool(const DelayedDiagnosticPool *parent) : Parent(parent) {}
269
270  DelayedDiagnosticPool(const DelayedDiagnosticPool &) = delete;
271  DelayedDiagnosticPool &operator=(const DelayedDiagnosticPool &) = delete;
272
273  DelayedDiagnosticPool(DelayedDiagnosticPool &&Other)
274      : Parent(Other.Parent), Diagnostics(std::move(Other.Diagnostics)) {
275    Other.Diagnostics.clear();
276  }
277
278  DelayedDiagnosticPool &operator=(DelayedDiagnosticPool &&Other) {
279    Parent = Other.Parent;
280    Diagnostics = std::move(Other.Diagnostics);
281    Other.Diagnostics.clear();
282    return *this;
283  }
284
285  ~DelayedDiagnosticPool() {
286    for (SmallVectorImpl<DelayedDiagnostic>::iterator
287           i = Diagnostics.begin(), e = Diagnostics.end(); i != e; ++i)
288      i->Destroy();
289  }
290
291  const DelayedDiagnosticPool *getParent() const { return Parent; }
292
293  /// Does this pool, or any of its ancestors, contain any diagnostics?
294  bool empty() const {
295    return (Diagnostics.empty() && (!Parent || Parent->empty()));
296  }
297
298  /// Add a diagnostic to this pool.
299  void add(const DelayedDiagnostic &diag) {
300    Diagnostics.push_back(diag);
301  }
302
303  /// Steal the diagnostics from the given pool.
304  void steal(DelayedDiagnosticPool &pool) {
305    if (pool.Diagnostics.empty()) return;
306
307    if (Diagnostics.empty()) {
308      Diagnostics = std::move(pool.Diagnostics);
309    } else {
310      Diagnostics.append(pool.pool_begin(), pool.pool_end());
311    }
312    pool.Diagnostics.clear();
313  }
314
315  using pool_iterator = SmallVectorImpl<DelayedDiagnostic>::const_iterator;
316
317  pool_iterator pool_begin() const { return Diagnostics.begin(); }
318  pool_iterator pool_end() const { return Diagnostics.end(); }
319  bool pool_empty() const { return Diagnostics.empty(); }
320};
321
322} // namespace clang
323
324/// Add a diagnostic to the current delay pool.
325inline void Sema::DelayedDiagnostics::add(const sema::DelayedDiagnostic &diag) {
326  assert(shouldDelayDiagnostics() && "trying to delay without pool");
327  CurPool->add(diag);
328}
329
330} // namespace clang
331
332#endif // LLVM_CLANG_SEMA_DELAYEDDIAGNOSTIC_H
333