Bug Summary

File:tools/clang/lib/Sema/SemaAccess.cpp
Warning:line 1248, column 34
Access to field 'Base' results in a dereference of a null pointer (loaded from variable 'constrainingBase')

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaAccess.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/lib/Sema -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp -faddrsig
1//===---- SemaAccess.cpp - C++ Access Control -------------------*- 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 provides Sema routines for C++ access control semantics.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Basic/Specifiers.h"
15#include "clang/Sema/SemaInternal.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/DeclCXX.h"
19#include "clang/AST/DeclFriend.h"
20#include "clang/AST/DeclObjC.h"
21#include "clang/AST/DependentDiagnostic.h"
22#include "clang/AST/ExprCXX.h"
23#include "clang/Sema/DelayedDiagnostic.h"
24#include "clang/Sema/Initialization.h"
25#include "clang/Sema/Lookup.h"
26
27using namespace clang;
28using namespace sema;
29
30/// A copy of Sema's enum without AR_delayed.
31enum AccessResult {
32 AR_accessible,
33 AR_inaccessible,
34 AR_dependent
35};
36
37/// SetMemberAccessSpecifier - Set the access specifier of a member.
38/// Returns true on error (when the previous member decl access specifier
39/// is different from the new member decl access specifier).
40bool Sema::SetMemberAccessSpecifier(NamedDecl *MemberDecl,
41 NamedDecl *PrevMemberDecl,
42 AccessSpecifier LexicalAS) {
43 if (!PrevMemberDecl) {
44 // Use the lexical access specifier.
45 MemberDecl->setAccess(LexicalAS);
46 return false;
47 }
48
49 // C++ [class.access.spec]p3: When a member is redeclared its access
50 // specifier must be same as its initial declaration.
51 if (LexicalAS != AS_none && LexicalAS != PrevMemberDecl->getAccess()) {
52 Diag(MemberDecl->getLocation(),
53 diag::err_class_redeclared_with_different_access)
54 << MemberDecl << LexicalAS;
55 Diag(PrevMemberDecl->getLocation(), diag::note_previous_access_declaration)
56 << PrevMemberDecl << PrevMemberDecl->getAccess();
57
58 MemberDecl->setAccess(LexicalAS);
59 return true;
60 }
61
62 MemberDecl->setAccess(PrevMemberDecl->getAccess());
63 return false;
64}
65
66static CXXRecordDecl *FindDeclaringClass(NamedDecl *D) {
67 DeclContext *DC = D->getDeclContext();
68
69 // This can only happen at top: enum decls only "publish" their
70 // immediate members.
71 if (isa<EnumDecl>(DC))
72 DC = cast<EnumDecl>(DC)->getDeclContext();
73
74 CXXRecordDecl *DeclaringClass = cast<CXXRecordDecl>(DC);
75 while (DeclaringClass->isAnonymousStructOrUnion())
76 DeclaringClass = cast<CXXRecordDecl>(DeclaringClass->getDeclContext());
77 return DeclaringClass;
78}
79
80namespace {
81struct EffectiveContext {
82 EffectiveContext() : Inner(nullptr), Dependent(false) {}
83
84 explicit EffectiveContext(DeclContext *DC)
85 : Inner(DC),
86 Dependent(DC->isDependentContext()) {
87
88 // C++11 [class.access.nest]p1:
89 // A nested class is a member and as such has the same access
90 // rights as any other member.
91 // C++11 [class.access]p2:
92 // A member of a class can also access all the names to which
93 // the class has access. A local class of a member function
94 // may access the same names that the member function itself
95 // may access.
96 // This almost implies that the privileges of nesting are transitive.
97 // Technically it says nothing about the local classes of non-member
98 // functions (which can gain privileges through friendship), but we
99 // take that as an oversight.
100 while (true) {
101 // We want to add canonical declarations to the EC lists for
102 // simplicity of checking, but we need to walk up through the
103 // actual current DC chain. Otherwise, something like a local
104 // extern or friend which happens to be the canonical
105 // declaration will really mess us up.
106
107 if (isa<CXXRecordDecl>(DC)) {
108 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
109 Records.push_back(Record->getCanonicalDecl());
110 DC = Record->getDeclContext();
111 } else if (isa<FunctionDecl>(DC)) {
112 FunctionDecl *Function = cast<FunctionDecl>(DC);
113 Functions.push_back(Function->getCanonicalDecl());
114 if (Function->getFriendObjectKind())
115 DC = Function->getLexicalDeclContext();
116 else
117 DC = Function->getDeclContext();
118 } else if (DC->isFileContext()) {
119 break;
120 } else {
121 DC = DC->getParent();
122 }
123 }
124 }
125
126 bool isDependent() const { return Dependent; }
127
128 bool includesClass(const CXXRecordDecl *R) const {
129 R = R->getCanonicalDecl();
130 return std::find(Records.begin(), Records.end(), R)
131 != Records.end();
132 }
133
134 /// Retrieves the innermost "useful" context. Can be null if we're
135 /// doing access-control without privileges.
136 DeclContext *getInnerContext() const {
137 return Inner;
138 }
139
140 typedef SmallVectorImpl<CXXRecordDecl*>::const_iterator record_iterator;
141
142 DeclContext *Inner;
143 SmallVector<FunctionDecl*, 4> Functions;
144 SmallVector<CXXRecordDecl*, 4> Records;
145 bool Dependent;
146};
147
148/// Like sema::AccessedEntity, but kindly lets us scribble all over
149/// it.
150struct AccessTarget : public AccessedEntity {
151 AccessTarget(const AccessedEntity &Entity)
152 : AccessedEntity(Entity) {
153 initialize();
154 }
155
156 AccessTarget(ASTContext &Context,
157 MemberNonce _,
158 CXXRecordDecl *NamingClass,
159 DeclAccessPair FoundDecl,
160 QualType BaseObjectType)
161 : AccessedEntity(Context.getDiagAllocator(), Member, NamingClass,
162 FoundDecl, BaseObjectType) {
163 initialize();
164 }
165
166 AccessTarget(ASTContext &Context,
167 BaseNonce _,
168 CXXRecordDecl *BaseClass,
169 CXXRecordDecl *DerivedClass,
170 AccessSpecifier Access)
171 : AccessedEntity(Context.getDiagAllocator(), Base, BaseClass, DerivedClass,
172 Access) {
173 initialize();
174 }
175
176 bool isInstanceMember() const {
177 return (isMemberAccess() && getTargetDecl()->isCXXInstanceMember());
178 }
179
180 bool hasInstanceContext() const {
181 return HasInstanceContext;
182 }
183
184 class SavedInstanceContext {
185 public:
186 SavedInstanceContext(SavedInstanceContext &&S)
187 : Target(S.Target), Has(S.Has) {
188 S.Target = nullptr;
189 }
190 ~SavedInstanceContext() {
191 if (Target)
192 Target->HasInstanceContext = Has;
193 }
194
195 private:
196 friend struct AccessTarget;
197 explicit SavedInstanceContext(AccessTarget &Target)
198 : Target(&Target), Has(Target.HasInstanceContext) {}
199 AccessTarget *Target;
200 bool Has;
201 };
202
203 SavedInstanceContext saveInstanceContext() {
204 return SavedInstanceContext(*this);
205 }
206
207 void suppressInstanceContext() {
208 HasInstanceContext = false;
209 }
210
211 const CXXRecordDecl *resolveInstanceContext(Sema &S) const {
212 assert(HasInstanceContext)((HasInstanceContext) ? static_cast<void> (0) : __assert_fail
("HasInstanceContext", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 212, __PRETTY_FUNCTION__))
;
213 if (CalculatedInstanceContext)
214 return InstanceContext;
215
216 CalculatedInstanceContext = true;
217 DeclContext *IC = S.computeDeclContext(getBaseObjectType());
218 InstanceContext = (IC ? cast<CXXRecordDecl>(IC)->getCanonicalDecl()
219 : nullptr);
220 return InstanceContext;
221 }
222
223 const CXXRecordDecl *getDeclaringClass() const {
224 return DeclaringClass;
225 }
226
227 /// The "effective" naming class is the canonical non-anonymous
228 /// class containing the actual naming class.
229 const CXXRecordDecl *getEffectiveNamingClass() const {
230 const CXXRecordDecl *namingClass = getNamingClass();
231 while (namingClass->isAnonymousStructOrUnion())
232 namingClass = cast<CXXRecordDecl>(namingClass->getParent());
233 return namingClass->getCanonicalDecl();
234 }
235
236private:
237 void initialize() {
238 HasInstanceContext = (isMemberAccess() &&
239 !getBaseObjectType().isNull() &&
240 getTargetDecl()->isCXXInstanceMember());
241 CalculatedInstanceContext = false;
242 InstanceContext = nullptr;
243
244 if (isMemberAccess())
245 DeclaringClass = FindDeclaringClass(getTargetDecl());
246 else
247 DeclaringClass = getBaseClass();
248 DeclaringClass = DeclaringClass->getCanonicalDecl();
249 }
250
251 bool HasInstanceContext : 1;
252 mutable bool CalculatedInstanceContext : 1;
253 mutable const CXXRecordDecl *InstanceContext;
254 const CXXRecordDecl *DeclaringClass;
255};
256
257}
258
259/// Checks whether one class might instantiate to the other.
260static bool MightInstantiateTo(const CXXRecordDecl *From,
261 const CXXRecordDecl *To) {
262 // Declaration names are always preserved by instantiation.
263 if (From->getDeclName() != To->getDeclName())
264 return false;
265
266 const DeclContext *FromDC = From->getDeclContext()->getPrimaryContext();
267 const DeclContext *ToDC = To->getDeclContext()->getPrimaryContext();
268 if (FromDC == ToDC) return true;
269 if (FromDC->isFileContext() || ToDC->isFileContext()) return false;
270
271 // Be conservative.
272 return true;
273}
274
275/// Checks whether one class is derived from another, inclusively.
276/// Properly indicates when it couldn't be determined due to
277/// dependence.
278///
279/// This should probably be donated to AST or at least Sema.
280static AccessResult IsDerivedFromInclusive(const CXXRecordDecl *Derived,
281 const CXXRecordDecl *Target) {
282 assert(Derived->getCanonicalDecl() == Derived)((Derived->getCanonicalDecl() == Derived) ? static_cast<
void> (0) : __assert_fail ("Derived->getCanonicalDecl() == Derived"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 282, __PRETTY_FUNCTION__))
;
283 assert(Target->getCanonicalDecl() == Target)((Target->getCanonicalDecl() == Target) ? static_cast<void
> (0) : __assert_fail ("Target->getCanonicalDecl() == Target"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 283, __PRETTY_FUNCTION__))
;
284
285 if (Derived == Target) return AR_accessible;
286
287 bool CheckDependent = Derived->isDependentContext();
288 if (CheckDependent && MightInstantiateTo(Derived, Target))
289 return AR_dependent;
290
291 AccessResult OnFailure = AR_inaccessible;
292 SmallVector<const CXXRecordDecl*, 8> Queue; // actually a stack
293
294 while (true) {
295 if (Derived->isDependentContext() && !Derived->hasDefinition() &&
296 !Derived->isLambda())
297 return AR_dependent;
298
299 for (const auto &I : Derived->bases()) {
300 const CXXRecordDecl *RD;
301
302 QualType T = I.getType();
303 if (const RecordType *RT = T->getAs<RecordType>()) {
304 RD = cast<CXXRecordDecl>(RT->getDecl());
305 } else if (const InjectedClassNameType *IT
306 = T->getAs<InjectedClassNameType>()) {
307 RD = IT->getDecl();
308 } else {
309 assert(T->isDependentType() && "non-dependent base wasn't a record?")((T->isDependentType() && "non-dependent base wasn't a record?"
) ? static_cast<void> (0) : __assert_fail ("T->isDependentType() && \"non-dependent base wasn't a record?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 309, __PRETTY_FUNCTION__))
;
310 OnFailure = AR_dependent;
311 continue;
312 }
313
314 RD = RD->getCanonicalDecl();
315 if (RD == Target) return AR_accessible;
316 if (CheckDependent && MightInstantiateTo(RD, Target))
317 OnFailure = AR_dependent;
318
319 Queue.push_back(RD);
320 }
321
322 if (Queue.empty()) break;
323
324 Derived = Queue.pop_back_val();
325 }
326
327 return OnFailure;
328}
329
330
331static bool MightInstantiateTo(Sema &S, DeclContext *Context,
332 DeclContext *Friend) {
333 if (Friend == Context)
334 return true;
335
336 assert(!Friend->isDependentContext() &&((!Friend->isDependentContext() && "can't handle friends with dependent contexts here"
) ? static_cast<void> (0) : __assert_fail ("!Friend->isDependentContext() && \"can't handle friends with dependent contexts here\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 337, __PRETTY_FUNCTION__))
337 "can't handle friends with dependent contexts here")((!Friend->isDependentContext() && "can't handle friends with dependent contexts here"
) ? static_cast<void> (0) : __assert_fail ("!Friend->isDependentContext() && \"can't handle friends with dependent contexts here\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 337, __PRETTY_FUNCTION__))
;
338
339 if (!Context->isDependentContext())
340 return false;
341
342 if (Friend->isFileContext())
343 return false;
344
345 // TODO: this is very conservative
346 return true;
347}
348
349// Asks whether the type in 'context' can ever instantiate to the type
350// in 'friend'.
351static bool MightInstantiateTo(Sema &S, CanQualType Context, CanQualType Friend) {
352 if (Friend == Context)
353 return true;
354
355 if (!Friend->isDependentType() && !Context->isDependentType())
356 return false;
357
358 // TODO: this is very conservative.
359 return true;
360}
361
362static bool MightInstantiateTo(Sema &S,
363 FunctionDecl *Context,
364 FunctionDecl *Friend) {
365 if (Context->getDeclName() != Friend->getDeclName())
366 return false;
367
368 if (!MightInstantiateTo(S,
369 Context->getDeclContext(),
370 Friend->getDeclContext()))
371 return false;
372
373 CanQual<FunctionProtoType> FriendTy
374 = S.Context.getCanonicalType(Friend->getType())
375 ->getAs<FunctionProtoType>();
376 CanQual<FunctionProtoType> ContextTy
377 = S.Context.getCanonicalType(Context->getType())
378 ->getAs<FunctionProtoType>();
379
380 // There isn't any way that I know of to add qualifiers
381 // during instantiation.
382 if (FriendTy.getQualifiers() != ContextTy.getQualifiers())
383 return false;
384
385 if (FriendTy->getNumParams() != ContextTy->getNumParams())
386 return false;
387
388 if (!MightInstantiateTo(S, ContextTy->getReturnType(),
389 FriendTy->getReturnType()))
390 return false;
391
392 for (unsigned I = 0, E = FriendTy->getNumParams(); I != E; ++I)
393 if (!MightInstantiateTo(S, ContextTy->getParamType(I),
394 FriendTy->getParamType(I)))
395 return false;
396
397 return true;
398}
399
400static bool MightInstantiateTo(Sema &S,
401 FunctionTemplateDecl *Context,
402 FunctionTemplateDecl *Friend) {
403 return MightInstantiateTo(S,
404 Context->getTemplatedDecl(),
405 Friend->getTemplatedDecl());
406}
407
408static AccessResult MatchesFriend(Sema &S,
409 const EffectiveContext &EC,
410 const CXXRecordDecl *Friend) {
411 if (EC.includesClass(Friend))
412 return AR_accessible;
413
414 if (EC.isDependent()) {
415 for (const CXXRecordDecl *Context : EC.Records) {
416 if (MightInstantiateTo(Context, Friend))
417 return AR_dependent;
418 }
419 }
420
421 return AR_inaccessible;
422}
423
424static AccessResult MatchesFriend(Sema &S,
425 const EffectiveContext &EC,
426 CanQualType Friend) {
427 if (const RecordType *RT = Friend->getAs<RecordType>())
428 return MatchesFriend(S, EC, cast<CXXRecordDecl>(RT->getDecl()));
429
430 // TODO: we can do better than this
431 if (Friend->isDependentType())
432 return AR_dependent;
433
434 return AR_inaccessible;
435}
436
437/// Determines whether the given friend class template matches
438/// anything in the effective context.
439static AccessResult MatchesFriend(Sema &S,
440 const EffectiveContext &EC,
441 ClassTemplateDecl *Friend) {
442 AccessResult OnFailure = AR_inaccessible;
443
444 // Check whether the friend is the template of a class in the
445 // context chain.
446 for (SmallVectorImpl<CXXRecordDecl*>::const_iterator
447 I = EC.Records.begin(), E = EC.Records.end(); I != E; ++I) {
448 CXXRecordDecl *Record = *I;
449
450 // Figure out whether the current class has a template:
451 ClassTemplateDecl *CTD;
452
453 // A specialization of the template...
454 if (isa<ClassTemplateSpecializationDecl>(Record)) {
455 CTD = cast<ClassTemplateSpecializationDecl>(Record)
456 ->getSpecializedTemplate();
457
458 // ... or the template pattern itself.
459 } else {
460 CTD = Record->getDescribedClassTemplate();
461 if (!CTD) continue;
462 }
463
464 // It's a match.
465 if (Friend == CTD->getCanonicalDecl())
466 return AR_accessible;
467
468 // If the context isn't dependent, it can't be a dependent match.
469 if (!EC.isDependent())
470 continue;
471
472 // If the template names don't match, it can't be a dependent
473 // match.
474 if (CTD->getDeclName() != Friend->getDeclName())
475 continue;
476
477 // If the class's context can't instantiate to the friend's
478 // context, it can't be a dependent match.
479 if (!MightInstantiateTo(S, CTD->getDeclContext(),
480 Friend->getDeclContext()))
481 continue;
482
483 // Otherwise, it's a dependent match.
484 OnFailure = AR_dependent;
485 }
486
487 return OnFailure;
488}
489
490/// Determines whether the given friend function matches anything in
491/// the effective context.
492static AccessResult MatchesFriend(Sema &S,
493 const EffectiveContext &EC,
494 FunctionDecl *Friend) {
495 AccessResult OnFailure = AR_inaccessible;
496
497 for (SmallVectorImpl<FunctionDecl*>::const_iterator
498 I = EC.Functions.begin(), E = EC.Functions.end(); I != E; ++I) {
499 if (Friend == *I)
500 return AR_accessible;
501
502 if (EC.isDependent() && MightInstantiateTo(S, *I, Friend))
503 OnFailure = AR_dependent;
504 }
505
506 return OnFailure;
507}
508
509/// Determines whether the given friend function template matches
510/// anything in the effective context.
511static AccessResult MatchesFriend(Sema &S,
512 const EffectiveContext &EC,
513 FunctionTemplateDecl *Friend) {
514 if (EC.Functions.empty()) return AR_inaccessible;
515
516 AccessResult OnFailure = AR_inaccessible;
517
518 for (SmallVectorImpl<FunctionDecl*>::const_iterator
519 I = EC.Functions.begin(), E = EC.Functions.end(); I != E; ++I) {
520
521 FunctionTemplateDecl *FTD = (*I)->getPrimaryTemplate();
522 if (!FTD)
523 FTD = (*I)->getDescribedFunctionTemplate();
524 if (!FTD)
525 continue;
526
527 FTD = FTD->getCanonicalDecl();
528
529 if (Friend == FTD)
530 return AR_accessible;
531
532 if (EC.isDependent() && MightInstantiateTo(S, FTD, Friend))
533 OnFailure = AR_dependent;
534 }
535
536 return OnFailure;
537}
538
539/// Determines whether the given friend declaration matches anything
540/// in the effective context.
541static AccessResult MatchesFriend(Sema &S,
542 const EffectiveContext &EC,
543 FriendDecl *FriendD) {
544 // Whitelist accesses if there's an invalid or unsupported friend
545 // declaration.
546 if (FriendD->isInvalidDecl() || FriendD->isUnsupportedFriend())
547 return AR_accessible;
548
549 if (TypeSourceInfo *T = FriendD->getFriendType())
550 return MatchesFriend(S, EC, T->getType()->getCanonicalTypeUnqualified());
551
552 NamedDecl *Friend
553 = cast<NamedDecl>(FriendD->getFriendDecl()->getCanonicalDecl());
554
555 // FIXME: declarations with dependent or templated scope.
556
557 if (isa<ClassTemplateDecl>(Friend))
558 return MatchesFriend(S, EC, cast<ClassTemplateDecl>(Friend));
559
560 if (isa<FunctionTemplateDecl>(Friend))
561 return MatchesFriend(S, EC, cast<FunctionTemplateDecl>(Friend));
562
563 if (isa<CXXRecordDecl>(Friend))
564 return MatchesFriend(S, EC, cast<CXXRecordDecl>(Friend));
565
566 assert(isa<FunctionDecl>(Friend) && "unknown friend decl kind")((isa<FunctionDecl>(Friend) && "unknown friend decl kind"
) ? static_cast<void> (0) : __assert_fail ("isa<FunctionDecl>(Friend) && \"unknown friend decl kind\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 566, __PRETTY_FUNCTION__))
;
567 return MatchesFriend(S, EC, cast<FunctionDecl>(Friend));
568}
569
570static AccessResult GetFriendKind(Sema &S,
571 const EffectiveContext &EC,
572 const CXXRecordDecl *Class) {
573 AccessResult OnFailure = AR_inaccessible;
574
575 // Okay, check friends.
576 for (auto *Friend : Class->friends()) {
577 switch (MatchesFriend(S, EC, Friend)) {
578 case AR_accessible:
579 return AR_accessible;
580
581 case AR_inaccessible:
582 continue;
583
584 case AR_dependent:
585 OnFailure = AR_dependent;
586 break;
587 }
588 }
589
590 // That's it, give up.
591 return OnFailure;
592}
593
594namespace {
595
596/// A helper class for checking for a friend which will grant access
597/// to a protected instance member.
598struct ProtectedFriendContext {
599 Sema &S;
600 const EffectiveContext &EC;
601 const CXXRecordDecl *NamingClass;
602 bool CheckDependent;
603 bool EverDependent;
604
605 /// The path down to the current base class.
606 SmallVector<const CXXRecordDecl*, 20> CurPath;
607
608 ProtectedFriendContext(Sema &S, const EffectiveContext &EC,
609 const CXXRecordDecl *InstanceContext,
610 const CXXRecordDecl *NamingClass)
611 : S(S), EC(EC), NamingClass(NamingClass),
612 CheckDependent(InstanceContext->isDependentContext() ||
613 NamingClass->isDependentContext()),
614 EverDependent(false) {}
615
616 /// Check classes in the current path for friendship, starting at
617 /// the given index.
618 bool checkFriendshipAlongPath(unsigned I) {
619 assert(I < CurPath.size())((I < CurPath.size()) ? static_cast<void> (0) : __assert_fail
("I < CurPath.size()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 619, __PRETTY_FUNCTION__))
;
620 for (unsigned E = CurPath.size(); I != E; ++I) {
621 switch (GetFriendKind(S, EC, CurPath[I])) {
622 case AR_accessible: return true;
623 case AR_inaccessible: continue;
624 case AR_dependent: EverDependent = true; continue;
625 }
626 }
627 return false;
628 }
629
630 /// Perform a search starting at the given class.
631 ///
632 /// PrivateDepth is the index of the last (least derived) class
633 /// along the current path such that a notional public member of
634 /// the final class in the path would have access in that class.
635 bool findFriendship(const CXXRecordDecl *Cur, unsigned PrivateDepth) {
636 // If we ever reach the naming class, check the current path for
637 // friendship. We can also stop recursing because we obviously
638 // won't find the naming class there again.
639 if (Cur == NamingClass)
640 return checkFriendshipAlongPath(PrivateDepth);
641
642 if (CheckDependent && MightInstantiateTo(Cur, NamingClass))
643 EverDependent = true;
644
645 // Recurse into the base classes.
646 for (const auto &I : Cur->bases()) {
647 // If this is private inheritance, then a public member of the
648 // base will not have any access in classes derived from Cur.
649 unsigned BasePrivateDepth = PrivateDepth;
650 if (I.getAccessSpecifier() == AS_private)
651 BasePrivateDepth = CurPath.size() - 1;
652
653 const CXXRecordDecl *RD;
654
655 QualType T = I.getType();
656 if (const RecordType *RT = T->getAs<RecordType>()) {
657 RD = cast<CXXRecordDecl>(RT->getDecl());
658 } else if (const InjectedClassNameType *IT
659 = T->getAs<InjectedClassNameType>()) {
660 RD = IT->getDecl();
661 } else {
662 assert(T->isDependentType() && "non-dependent base wasn't a record?")((T->isDependentType() && "non-dependent base wasn't a record?"
) ? static_cast<void> (0) : __assert_fail ("T->isDependentType() && \"non-dependent base wasn't a record?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 662, __PRETTY_FUNCTION__))
;
663 EverDependent = true;
664 continue;
665 }
666
667 // Recurse. We don't need to clean up if this returns true.
668 CurPath.push_back(RD);
669 if (findFriendship(RD->getCanonicalDecl(), BasePrivateDepth))
670 return true;
671 CurPath.pop_back();
672 }
673
674 return false;
675 }
676
677 bool findFriendship(const CXXRecordDecl *Cur) {
678 assert(CurPath.empty())((CurPath.empty()) ? static_cast<void> (0) : __assert_fail
("CurPath.empty()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 678, __PRETTY_FUNCTION__))
;
679 CurPath.push_back(Cur);
680 return findFriendship(Cur, 0);
681 }
682};
683}
684
685/// Search for a class P that EC is a friend of, under the constraint
686/// InstanceContext <= P
687/// if InstanceContext exists, or else
688/// NamingClass <= P
689/// and with the additional restriction that a protected member of
690/// NamingClass would have some natural access in P, which implicitly
691/// imposes the constraint that P <= NamingClass.
692///
693/// This isn't quite the condition laid out in the standard.
694/// Instead of saying that a notional protected member of NamingClass
695/// would have to have some natural access in P, it says the actual
696/// target has to have some natural access in P, which opens up the
697/// possibility that the target (which is not necessarily a member
698/// of NamingClass) might be more accessible along some path not
699/// passing through it. That's really a bad idea, though, because it
700/// introduces two problems:
701/// - Most importantly, it breaks encapsulation because you can
702/// access a forbidden base class's members by directly subclassing
703/// it elsewhere.
704/// - It also makes access substantially harder to compute because it
705/// breaks the hill-climbing algorithm: knowing that the target is
706/// accessible in some base class would no longer let you change
707/// the question solely to whether the base class is accessible,
708/// because the original target might have been more accessible
709/// because of crazy subclassing.
710/// So we don't implement that.
711static AccessResult GetProtectedFriendKind(Sema &S, const EffectiveContext &EC,
712 const CXXRecordDecl *InstanceContext,
713 const CXXRecordDecl *NamingClass) {
714 assert(InstanceContext == nullptr ||((InstanceContext == nullptr || InstanceContext->getCanonicalDecl
() == InstanceContext) ? static_cast<void> (0) : __assert_fail
("InstanceContext == nullptr || InstanceContext->getCanonicalDecl() == InstanceContext"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 715, __PRETTY_FUNCTION__))
715 InstanceContext->getCanonicalDecl() == InstanceContext)((InstanceContext == nullptr || InstanceContext->getCanonicalDecl
() == InstanceContext) ? static_cast<void> (0) : __assert_fail
("InstanceContext == nullptr || InstanceContext->getCanonicalDecl() == InstanceContext"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 715, __PRETTY_FUNCTION__))
;
716 assert(NamingClass->getCanonicalDecl() == NamingClass)((NamingClass->getCanonicalDecl() == NamingClass) ? static_cast
<void> (0) : __assert_fail ("NamingClass->getCanonicalDecl() == NamingClass"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 716, __PRETTY_FUNCTION__))
;
717
718 // If we don't have an instance context, our constraints give us
719 // that NamingClass <= P <= NamingClass, i.e. P == NamingClass.
720 // This is just the usual friendship check.
721 if (!InstanceContext) return GetFriendKind(S, EC, NamingClass);
722
723 ProtectedFriendContext PRC(S, EC, InstanceContext, NamingClass);
724 if (PRC.findFriendship(InstanceContext)) return AR_accessible;
725 if (PRC.EverDependent) return AR_dependent;
726 return AR_inaccessible;
727}
728
729static AccessResult HasAccess(Sema &S,
730 const EffectiveContext &EC,
731 const CXXRecordDecl *NamingClass,
732 AccessSpecifier Access,
733 const AccessTarget &Target) {
734 assert(NamingClass->getCanonicalDecl() == NamingClass &&((NamingClass->getCanonicalDecl() == NamingClass &&
"declaration should be canonicalized before being passed here"
) ? static_cast<void> (0) : __assert_fail ("NamingClass->getCanonicalDecl() == NamingClass && \"declaration should be canonicalized before being passed here\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 735, __PRETTY_FUNCTION__))
735 "declaration should be canonicalized before being passed here")((NamingClass->getCanonicalDecl() == NamingClass &&
"declaration should be canonicalized before being passed here"
) ? static_cast<void> (0) : __assert_fail ("NamingClass->getCanonicalDecl() == NamingClass && \"declaration should be canonicalized before being passed here\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 735, __PRETTY_FUNCTION__))
;
736
737 if (Access == AS_public) return AR_accessible;
738 assert(Access == AS_private || Access == AS_protected)((Access == AS_private || Access == AS_protected) ? static_cast
<void> (0) : __assert_fail ("Access == AS_private || Access == AS_protected"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 738, __PRETTY_FUNCTION__))
;
739
740 AccessResult OnFailure = AR_inaccessible;
741
742 for (EffectiveContext::record_iterator
743 I = EC.Records.begin(), E = EC.Records.end(); I != E; ++I) {
744 // All the declarations in EC have been canonicalized, so pointer
745 // equality from this point on will work fine.
746 const CXXRecordDecl *ECRecord = *I;
747
748 // [B2] and [M2]
749 if (Access == AS_private) {
750 if (ECRecord == NamingClass)
751 return AR_accessible;
752
753 if (EC.isDependent() && MightInstantiateTo(ECRecord, NamingClass))
754 OnFailure = AR_dependent;
755
756 // [B3] and [M3]
757 } else {
758 assert(Access == AS_protected)((Access == AS_protected) ? static_cast<void> (0) : __assert_fail
("Access == AS_protected", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 758, __PRETTY_FUNCTION__))
;
759 switch (IsDerivedFromInclusive(ECRecord, NamingClass)) {
760 case AR_accessible: break;
761 case AR_inaccessible: continue;
762 case AR_dependent: OnFailure = AR_dependent; continue;
763 }
764
765 // C++ [class.protected]p1:
766 // An additional access check beyond those described earlier in
767 // [class.access] is applied when a non-static data member or
768 // non-static member function is a protected member of its naming
769 // class. As described earlier, access to a protected member is
770 // granted because the reference occurs in a friend or member of
771 // some class C. If the access is to form a pointer to member,
772 // the nested-name-specifier shall name C or a class derived from
773 // C. All other accesses involve a (possibly implicit) object
774 // expression. In this case, the class of the object expression
775 // shall be C or a class derived from C.
776 //
777 // We interpret this as a restriction on [M3].
778
779 // In this part of the code, 'C' is just our context class ECRecord.
780
781 // These rules are different if we don't have an instance context.
782 if (!Target.hasInstanceContext()) {
783 // If it's not an instance member, these restrictions don't apply.
784 if (!Target.isInstanceMember()) return AR_accessible;
785
786 // If it's an instance member, use the pointer-to-member rule
787 // that the naming class has to be derived from the effective
788 // context.
789
790 // Emulate a MSVC bug where the creation of pointer-to-member
791 // to protected member of base class is allowed but only from
792 // static member functions.
793 if (S.getLangOpts().MSVCCompat && !EC.Functions.empty())
794 if (CXXMethodDecl* MD = dyn_cast<CXXMethodDecl>(EC.Functions.front()))
795 if (MD->isStatic()) return AR_accessible;
796
797 // Despite the standard's confident wording, there is a case
798 // where you can have an instance member that's neither in a
799 // pointer-to-member expression nor in a member access: when
800 // it names a field in an unevaluated context that can't be an
801 // implicit member. Pending clarification, we just apply the
802 // same naming-class restriction here.
803 // FIXME: we're probably not correctly adding the
804 // protected-member restriction when we retroactively convert
805 // an expression to being evaluated.
806
807 // We know that ECRecord derives from NamingClass. The
808 // restriction says to check whether NamingClass derives from
809 // ECRecord, but that's not really necessary: two distinct
810 // classes can't be recursively derived from each other. So
811 // along this path, we just need to check whether the classes
812 // are equal.
813 if (NamingClass == ECRecord) return AR_accessible;
814
815 // Otherwise, this context class tells us nothing; on to the next.
816 continue;
817 }
818
819 assert(Target.isInstanceMember())((Target.isInstanceMember()) ? static_cast<void> (0) : __assert_fail
("Target.isInstanceMember()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 819, __PRETTY_FUNCTION__))
;
820
821 const CXXRecordDecl *InstanceContext = Target.resolveInstanceContext(S);
822 if (!InstanceContext) {
823 OnFailure = AR_dependent;
824 continue;
825 }
826
827 switch (IsDerivedFromInclusive(InstanceContext, ECRecord)) {
828 case AR_accessible: return AR_accessible;
829 case AR_inaccessible: continue;
830 case AR_dependent: OnFailure = AR_dependent; continue;
831 }
832 }
833 }
834
835 // [M3] and [B3] say that, if the target is protected in N, we grant
836 // access if the access occurs in a friend or member of some class P
837 // that's a subclass of N and where the target has some natural
838 // access in P. The 'member' aspect is easy to handle because P
839 // would necessarily be one of the effective-context records, and we
840 // address that above. The 'friend' aspect is completely ridiculous
841 // to implement because there are no restrictions at all on P
842 // *unless* the [class.protected] restriction applies. If it does,
843 // however, we should ignore whether the naming class is a friend,
844 // and instead rely on whether any potential P is a friend.
845 if (Access == AS_protected && Target.isInstanceMember()) {
846 // Compute the instance context if possible.
847 const CXXRecordDecl *InstanceContext = nullptr;
848 if (Target.hasInstanceContext()) {
849 InstanceContext = Target.resolveInstanceContext(S);
850 if (!InstanceContext) return AR_dependent;
851 }
852
853 switch (GetProtectedFriendKind(S, EC, InstanceContext, NamingClass)) {
854 case AR_accessible: return AR_accessible;
855 case AR_inaccessible: return OnFailure;
856 case AR_dependent: return AR_dependent;
857 }
858 llvm_unreachable("impossible friendship kind")::llvm::llvm_unreachable_internal("impossible friendship kind"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 858)
;
859 }
860
861 switch (GetFriendKind(S, EC, NamingClass)) {
862 case AR_accessible: return AR_accessible;
863 case AR_inaccessible: return OnFailure;
864 case AR_dependent: return AR_dependent;
865 }
866
867 // Silence bogus warnings
868 llvm_unreachable("impossible friendship kind")::llvm::llvm_unreachable_internal("impossible friendship kind"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 868)
;
869}
870
871/// Finds the best path from the naming class to the declaring class,
872/// taking friend declarations into account.
873///
874/// C++0x [class.access.base]p5:
875/// A member m is accessible at the point R when named in class N if
876/// [M1] m as a member of N is public, or
877/// [M2] m as a member of N is private, and R occurs in a member or
878/// friend of class N, or
879/// [M3] m as a member of N is protected, and R occurs in a member or
880/// friend of class N, or in a member or friend of a class P
881/// derived from N, where m as a member of P is public, private,
882/// or protected, or
883/// [M4] there exists a base class B of N that is accessible at R, and
884/// m is accessible at R when named in class B.
885///
886/// C++0x [class.access.base]p4:
887/// A base class B of N is accessible at R, if
888/// [B1] an invented public member of B would be a public member of N, or
889/// [B2] R occurs in a member or friend of class N, and an invented public
890/// member of B would be a private or protected member of N, or
891/// [B3] R occurs in a member or friend of a class P derived from N, and an
892/// invented public member of B would be a private or protected member
893/// of P, or
894/// [B4] there exists a class S such that B is a base class of S accessible
895/// at R and S is a base class of N accessible at R.
896///
897/// Along a single inheritance path we can restate both of these
898/// iteratively:
899///
900/// First, we note that M1-4 are equivalent to B1-4 if the member is
901/// treated as a notional base of its declaring class with inheritance
902/// access equivalent to the member's access. Therefore we need only
903/// ask whether a class B is accessible from a class N in context R.
904///
905/// Let B_1 .. B_n be the inheritance path in question (i.e. where
906/// B_1 = N, B_n = B, and for all i, B_{i+1} is a direct base class of
907/// B_i). For i in 1..n, we will calculate ACAB(i), the access to the
908/// closest accessible base in the path:
909/// Access(a, b) = (* access on the base specifier from a to b *)
910/// Merge(a, forbidden) = forbidden
911/// Merge(a, private) = forbidden
912/// Merge(a, b) = min(a,b)
913/// Accessible(c, forbidden) = false
914/// Accessible(c, private) = (R is c) || IsFriend(c, R)
915/// Accessible(c, protected) = (R derived from c) || IsFriend(c, R)
916/// Accessible(c, public) = true
917/// ACAB(n) = public
918/// ACAB(i) =
919/// let AccessToBase = Merge(Access(B_i, B_{i+1}), ACAB(i+1)) in
920/// if Accessible(B_i, AccessToBase) then public else AccessToBase
921///
922/// B is an accessible base of N at R iff ACAB(1) = public.
923///
924/// \param FinalAccess the access of the "final step", or AS_public if
925/// there is no final step.
926/// \return null if friendship is dependent
927static CXXBasePath *FindBestPath(Sema &S,
928 const EffectiveContext &EC,
929 AccessTarget &Target,
930 AccessSpecifier FinalAccess,
931 CXXBasePaths &Paths) {
932 // Derive the paths to the desired base.
933 const CXXRecordDecl *Derived = Target.getNamingClass();
934 const CXXRecordDecl *Base = Target.getDeclaringClass();
935
936 // FIXME: fail correctly when there are dependent paths.
937 bool isDerived = Derived->isDerivedFrom(const_cast<CXXRecordDecl*>(Base),
938 Paths);
939 assert(isDerived && "derived class not actually derived from base")((isDerived && "derived class not actually derived from base"
) ? static_cast<void> (0) : __assert_fail ("isDerived && \"derived class not actually derived from base\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 939, __PRETTY_FUNCTION__))
;
940 (void) isDerived;
941
942 CXXBasePath *BestPath = nullptr;
943
944 assert(FinalAccess != AS_none && "forbidden access after declaring class")((FinalAccess != AS_none && "forbidden access after declaring class"
) ? static_cast<void> (0) : __assert_fail ("FinalAccess != AS_none && \"forbidden access after declaring class\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 944, __PRETTY_FUNCTION__))
;
945
946 bool AnyDependent = false;
947
948 // Derive the friend-modified access along each path.
949 for (CXXBasePaths::paths_iterator PI = Paths.begin(), PE = Paths.end();
950 PI != PE; ++PI) {
951 AccessTarget::SavedInstanceContext _ = Target.saveInstanceContext();
952
953 // Walk through the path backwards.
954 AccessSpecifier PathAccess = FinalAccess;
955 CXXBasePath::iterator I = PI->end(), E = PI->begin();
956 while (I != E) {
957 --I;
958
959 assert(PathAccess != AS_none)((PathAccess != AS_none) ? static_cast<void> (0) : __assert_fail
("PathAccess != AS_none", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 959, __PRETTY_FUNCTION__))
;
960
961 // If the declaration is a private member of a base class, there
962 // is no level of friendship in derived classes that can make it
963 // accessible.
964 if (PathAccess == AS_private) {
965 PathAccess = AS_none;
966 break;
967 }
968
969 const CXXRecordDecl *NC = I->Class->getCanonicalDecl();
970
971 AccessSpecifier BaseAccess = I->Base->getAccessSpecifier();
972 PathAccess = std::max(PathAccess, BaseAccess);
973
974 switch (HasAccess(S, EC, NC, PathAccess, Target)) {
975 case AR_inaccessible: break;
976 case AR_accessible:
977 PathAccess = AS_public;
978
979 // Future tests are not against members and so do not have
980 // instance context.
981 Target.suppressInstanceContext();
982 break;
983 case AR_dependent:
984 AnyDependent = true;
985 goto Next;
986 }
987 }
988
989 // Note that we modify the path's Access field to the
990 // friend-modified access.
991 if (BestPath == nullptr || PathAccess < BestPath->Access) {
992 BestPath = &*PI;
993 BestPath->Access = PathAccess;
994
995 // Short-circuit if we found a public path.
996 if (BestPath->Access == AS_public)
997 return BestPath;
998 }
999
1000 Next: ;
1001 }
1002
1003 assert((!BestPath || BestPath->Access != AS_public) &&(((!BestPath || BestPath->Access != AS_public) && "fell out of loop with public path"
) ? static_cast<void> (0) : __assert_fail ("(!BestPath || BestPath->Access != AS_public) && \"fell out of loop with public path\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1004, __PRETTY_FUNCTION__))
1004 "fell out of loop with public path")(((!BestPath || BestPath->Access != AS_public) && "fell out of loop with public path"
) ? static_cast<void> (0) : __assert_fail ("(!BestPath || BestPath->Access != AS_public) && \"fell out of loop with public path\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1004, __PRETTY_FUNCTION__))
;
1005
1006 // We didn't find a public path, but at least one path was subject
1007 // to dependent friendship, so delay the check.
1008 if (AnyDependent)
1009 return nullptr;
1010
1011 return BestPath;
1012}
1013
1014/// Given that an entity has protected natural access, check whether
1015/// access might be denied because of the protected member access
1016/// restriction.
1017///
1018/// \return true if a note was emitted
1019static bool TryDiagnoseProtectedAccess(Sema &S, const EffectiveContext &EC,
1020 AccessTarget &Target) {
1021 // Only applies to instance accesses.
1022 if (!Target.isInstanceMember())
1023 return false;
1024
1025 assert(Target.isMemberAccess())((Target.isMemberAccess()) ? static_cast<void> (0) : __assert_fail
("Target.isMemberAccess()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1025, __PRETTY_FUNCTION__))
;
1026
1027 const CXXRecordDecl *NamingClass = Target.getEffectiveNamingClass();
1028
1029 for (EffectiveContext::record_iterator
1030 I = EC.Records.begin(), E = EC.Records.end(); I != E; ++I) {
1031 const CXXRecordDecl *ECRecord = *I;
1032 switch (IsDerivedFromInclusive(ECRecord, NamingClass)) {
1033 case AR_accessible: break;
1034 case AR_inaccessible: continue;
1035 case AR_dependent: continue;
1036 }
1037
1038 // The effective context is a subclass of the declaring class.
1039 // Check whether the [class.protected] restriction is limiting
1040 // access.
1041
1042 // To get this exactly right, this might need to be checked more
1043 // holistically; it's not necessarily the case that gaining
1044 // access here would grant us access overall.
1045
1046 NamedDecl *D = Target.getTargetDecl();
1047
1048 // If we don't have an instance context, [class.protected] says the
1049 // naming class has to equal the context class.
1050 if (!Target.hasInstanceContext()) {
1051 // If it does, the restriction doesn't apply.
1052 if (NamingClass == ECRecord) continue;
1053
1054 // TODO: it would be great to have a fixit here, since this is
1055 // such an obvious error.
1056 S.Diag(D->getLocation(), diag::note_access_protected_restricted_noobject)
1057 << S.Context.getTypeDeclType(ECRecord);
1058 return true;
1059 }
1060
1061 const CXXRecordDecl *InstanceContext = Target.resolveInstanceContext(S);
1062 assert(InstanceContext && "diagnosing dependent access")((InstanceContext && "diagnosing dependent access") ?
static_cast<void> (0) : __assert_fail ("InstanceContext && \"diagnosing dependent access\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1062, __PRETTY_FUNCTION__))
;
1063
1064 switch (IsDerivedFromInclusive(InstanceContext, ECRecord)) {
1065 case AR_accessible: continue;
1066 case AR_dependent: continue;
1067 case AR_inaccessible:
1068 break;
1069 }
1070
1071 // Okay, the restriction seems to be what's limiting us.
1072
1073 // Use a special diagnostic for constructors and destructors.
1074 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D) ||
1075 (isa<FunctionTemplateDecl>(D) &&
1076 isa<CXXConstructorDecl>(
1077 cast<FunctionTemplateDecl>(D)->getTemplatedDecl()))) {
1078 return S.Diag(D->getLocation(),
1079 diag::note_access_protected_restricted_ctordtor)
1080 << isa<CXXDestructorDecl>(D->getAsFunction());
1081 }
1082
1083 // Otherwise, use the generic diagnostic.
1084 return S.Diag(D->getLocation(),
1085 diag::note_access_protected_restricted_object)
1086 << S.Context.getTypeDeclType(ECRecord);
1087 }
1088
1089 return false;
1090}
1091
1092/// We are unable to access a given declaration due to its direct
1093/// access control; diagnose that.
1094static void diagnoseBadDirectAccess(Sema &S,
1095 const EffectiveContext &EC,
1096 AccessTarget &entity) {
1097 assert(entity.isMemberAccess())((entity.isMemberAccess()) ? static_cast<void> (0) : __assert_fail
("entity.isMemberAccess()", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1097, __PRETTY_FUNCTION__))
;
1098 NamedDecl *D = entity.getTargetDecl();
1099
1100 if (D->getAccess() == AS_protected &&
1101 TryDiagnoseProtectedAccess(S, EC, entity))
1102 return;
1103
1104 // Find an original declaration.
1105 while (D->isOutOfLine()) {
1106 NamedDecl *PrevDecl = nullptr;
1107 if (VarDecl *VD = dyn_cast<VarDecl>(D))
1108 PrevDecl = VD->getPreviousDecl();
1109 else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
1110 PrevDecl = FD->getPreviousDecl();
1111 else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(D))
1112 PrevDecl = TND->getPreviousDecl();
1113 else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
1114 if (isa<RecordDecl>(D) && cast<RecordDecl>(D)->isInjectedClassName())
1115 break;
1116 PrevDecl = TD->getPreviousDecl();
1117 }
1118 if (!PrevDecl) break;
1119 D = PrevDecl;
1120 }
1121
1122 CXXRecordDecl *DeclaringClass = FindDeclaringClass(D);
1123 Decl *ImmediateChild;
1124 if (D->getDeclContext() == DeclaringClass)
1125 ImmediateChild = D;
1126 else {
1127 DeclContext *DC = D->getDeclContext();
1128 while (DC->getParent() != DeclaringClass)
1129 DC = DC->getParent();
1130 ImmediateChild = cast<Decl>(DC);
1131 }
1132
1133 // Check whether there's an AccessSpecDecl preceding this in the
1134 // chain of the DeclContext.
1135 bool isImplicit = true;
1136 for (const auto *I : DeclaringClass->decls()) {
1137 if (I == ImmediateChild) break;
1138 if (isa<AccessSpecDecl>(I)) {
1139 isImplicit = false;
1140 break;
1141 }
1142 }
1143
1144 S.Diag(D->getLocation(), diag::note_access_natural)
1145 << (unsigned) (D->getAccess() == AS_protected)
1146 << isImplicit;
1147}
1148
1149/// Diagnose the path which caused the given declaration or base class
1150/// to become inaccessible.
1151static void DiagnoseAccessPath(Sema &S,
1152 const EffectiveContext &EC,
1153 AccessTarget &entity) {
1154 // Save the instance context to preserve invariants.
1155 AccessTarget::SavedInstanceContext _ = entity.saveInstanceContext();
1156
1157 // This basically repeats the main algorithm but keeps some more
1158 // information.
1159
1160 // The natural access so far.
1161 AccessSpecifier accessSoFar = AS_public;
1162
1163 // Check whether we have special rights to the declaring class.
1164 if (entity.isMemberAccess()) {
18
Taking true branch
1165 NamedDecl *D = entity.getTargetDecl();
1166 accessSoFar = D->getAccess();
1167 const CXXRecordDecl *declaringClass = entity.getDeclaringClass();
1168
1169 switch (HasAccess(S, EC, declaringClass, accessSoFar, entity)) {
19
Control jumps to 'case AR_inaccessible:' at line 1177
1170 // If the declaration is accessible when named in its declaring
1171 // class, then we must be constrained by the path.
1172 case AR_accessible:
1173 accessSoFar = AS_public;
1174 entity.suppressInstanceContext();
1175 break;
1176
1177 case AR_inaccessible:
1178 if (accessSoFar == AS_private ||
20
Assuming 'accessSoFar' is not equal to AS_private
22
Taking false branch
1179 declaringClass == entity.getEffectiveNamingClass())
21
Assuming the condition is false
1180 return diagnoseBadDirectAccess(S, EC, entity);
1181 break;
23
Execution jumps to the end of the function
1182
1183 case AR_dependent:
1184 llvm_unreachable("cannot diagnose dependent access")::llvm::llvm_unreachable_internal("cannot diagnose dependent access"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1184)
;
1185 }
1186 }
1187
1188 CXXBasePaths paths;
1189 CXXBasePath &path = *FindBestPath(S, EC, entity, accessSoFar, paths);
1190 assert(path.Access != AS_public)((path.Access != AS_public) ? static_cast<void> (0) : __assert_fail
("path.Access != AS_public", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1190, __PRETTY_FUNCTION__))
;
1191
1192 CXXBasePath::iterator i = path.end(), e = path.begin();
1193 CXXBasePath::iterator constrainingBase = i;
1194 while (i != e) {
24
Assuming 'i' is not equal to 'e'
25
Loop condition is true. Entering loop body
32
Loop condition is false. Execution continues on line 1234
1195 --i;
1196
1197 assert(accessSoFar != AS_none && accessSoFar != AS_private)((accessSoFar != AS_none && accessSoFar != AS_private
) ? static_cast<void> (0) : __assert_fail ("accessSoFar != AS_none && accessSoFar != AS_private"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1197, __PRETTY_FUNCTION__))
;
1198
1199 // Is the entity accessible when named in the deriving class, as
1200 // modified by the base specifier?
1201 const CXXRecordDecl *derivingClass = i->Class->getCanonicalDecl();
1202 const CXXBaseSpecifier *base = i->Base;
1203
1204 // If the access to this base is worse than the access we have to
1205 // the declaration, remember it.
1206 AccessSpecifier baseAccess = base->getAccessSpecifier();
1207 if (baseAccess > accessSoFar) {
26
Assuming 'baseAccess' is <= 'accessSoFar'
27
Taking false branch
1208 constrainingBase = i;
1209 accessSoFar = baseAccess;
1210 }
1211
1212 switch (HasAccess(S, EC, derivingClass, accessSoFar, entity)) {
28
Control jumps to 'case AR_accessible:' at line 1214
1213 case AR_inaccessible: break;
1214 case AR_accessible:
1215 accessSoFar = AS_public;
1216 entity.suppressInstanceContext();
1217 constrainingBase = nullptr;
29
Null pointer value stored to 'constrainingBase'
1218 break;
30
Execution continues on line 1225
1219 case AR_dependent:
1220 llvm_unreachable("cannot diagnose dependent access")::llvm::llvm_unreachable_internal("cannot diagnose dependent access"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1220)
;
1221 }
1222
1223 // If this was private inheritance, but we don't have access to
1224 // the deriving class, we're done.
1225 if (accessSoFar == AS_private) {
31
Taking false branch
1226 assert(baseAccess == AS_private)((baseAccess == AS_private) ? static_cast<void> (0) : __assert_fail
("baseAccess == AS_private", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1226, __PRETTY_FUNCTION__))
;
1227 assert(constrainingBase == i)((constrainingBase == i) ? static_cast<void> (0) : __assert_fail
("constrainingBase == i", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1227, __PRETTY_FUNCTION__))
;
1228 break;
1229 }
1230 }
1231
1232 // If we don't have a constraining base, the access failure must be
1233 // due to the original declaration.
1234 if (constrainingBase == path.end())
33
Assuming the condition is false
34
Taking false branch
1235 return diagnoseBadDirectAccess(S, EC, entity);
1236
1237 // We're constrained by inheritance, but we want to say
1238 // "declared private here" if we're diagnosing a hierarchy
1239 // conversion and this is the final step.
1240 unsigned diagnostic;
1241 if (entity.isMemberAccess() ||
35
Assuming the condition is true
1242 constrainingBase + 1 != path.end()) {
1243 diagnostic = diag::note_access_constrained_by_path;
1244 } else {
1245 diagnostic = diag::note_access_natural;
1246 }
1247
1248 const CXXBaseSpecifier *base = constrainingBase->Base;
36
Access to field 'Base' results in a dereference of a null pointer (loaded from variable 'constrainingBase')
1249
1250 S.Diag(base->getSourceRange().getBegin(), diagnostic)
1251 << base->getSourceRange()
1252 << (base->getAccessSpecifier() == AS_protected)
1253 << (base->getAccessSpecifierAsWritten() == AS_none);
1254
1255 if (entity.isMemberAccess())
1256 S.Diag(entity.getTargetDecl()->getLocation(),
1257 diag::note_member_declared_at);
1258}
1259
1260static void DiagnoseBadAccess(Sema &S, SourceLocation Loc,
1261 const EffectiveContext &EC,
1262 AccessTarget &Entity) {
1263 const CXXRecordDecl *NamingClass = Entity.getNamingClass();
1264 const CXXRecordDecl *DeclaringClass = Entity.getDeclaringClass();
1265 NamedDecl *D = (Entity.isMemberAccess() ? Entity.getTargetDecl() : nullptr);
15
'?' condition is true
1266
1267 S.Diag(Loc, Entity.getDiag())
1268 << (Entity.getAccess() == AS_protected)
1269 << (D ? D->getDeclName() : DeclarationName())
16
'?' condition is true
1270 << S.Context.getTypeDeclType(NamingClass)
1271 << S.Context.getTypeDeclType(DeclaringClass);
1272 DiagnoseAccessPath(S, EC, Entity);
17
Calling 'DiagnoseAccessPath'
1273}
1274
1275/// MSVC has a bug where if during an using declaration name lookup,
1276/// the declaration found is unaccessible (private) and that declaration
1277/// was bring into scope via another using declaration whose target
1278/// declaration is accessible (public) then no error is generated.
1279/// Example:
1280/// class A {
1281/// public:
1282/// int f();
1283/// };
1284/// class B : public A {
1285/// private:
1286/// using A::f;
1287/// };
1288/// class C : public B {
1289/// private:
1290/// using B::f;
1291/// };
1292///
1293/// Here, B::f is private so this should fail in Standard C++, but
1294/// because B::f refers to A::f which is public MSVC accepts it.
1295static bool IsMicrosoftUsingDeclarationAccessBug(Sema& S,
1296 SourceLocation AccessLoc,
1297 AccessTarget &Entity) {
1298 if (UsingShadowDecl *Shadow =
1299 dyn_cast<UsingShadowDecl>(Entity.getTargetDecl())) {
1300 const NamedDecl *OrigDecl = Entity.getTargetDecl()->getUnderlyingDecl();
1301 if (Entity.getTargetDecl()->getAccess() == AS_private &&
1302 (OrigDecl->getAccess() == AS_public ||
1303 OrigDecl->getAccess() == AS_protected)) {
1304 S.Diag(AccessLoc, diag::ext_ms_using_declaration_inaccessible)
1305 << Shadow->getUsingDecl()->getQualifiedNameAsString()
1306 << OrigDecl->getQualifiedNameAsString();
1307 return true;
1308 }
1309 }
1310 return false;
1311}
1312
1313/// Determines whether the accessed entity is accessible. Public members
1314/// have been weeded out by this point.
1315static AccessResult IsAccessible(Sema &S,
1316 const EffectiveContext &EC,
1317 AccessTarget &Entity) {
1318 // Determine the actual naming class.
1319 const CXXRecordDecl *NamingClass = Entity.getEffectiveNamingClass();
1320
1321 AccessSpecifier UnprivilegedAccess = Entity.getAccess();
1322 assert(UnprivilegedAccess != AS_public && "public access not weeded out")((UnprivilegedAccess != AS_public && "public access not weeded out"
) ? static_cast<void> (0) : __assert_fail ("UnprivilegedAccess != AS_public && \"public access not weeded out\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1322, __PRETTY_FUNCTION__))
;
1323
1324 // Before we try to recalculate access paths, try to white-list
1325 // accesses which just trade in on the final step, i.e. accesses
1326 // which don't require [M4] or [B4]. These are by far the most
1327 // common forms of privileged access.
1328 if (UnprivilegedAccess != AS_none) {
1329 switch (HasAccess(S, EC, NamingClass, UnprivilegedAccess, Entity)) {
1330 case AR_dependent:
1331 // This is actually an interesting policy decision. We don't
1332 // *have* to delay immediately here: we can do the full access
1333 // calculation in the hope that friendship on some intermediate
1334 // class will make the declaration accessible non-dependently.
1335 // But that's not cheap, and odds are very good (note: assertion
1336 // made without data) that the friend declaration will determine
1337 // access.
1338 return AR_dependent;
1339
1340 case AR_accessible: return AR_accessible;
1341 case AR_inaccessible: break;
1342 }
1343 }
1344
1345 AccessTarget::SavedInstanceContext _ = Entity.saveInstanceContext();
1346
1347 // We lower member accesses to base accesses by pretending that the
1348 // member is a base class of its declaring class.
1349 AccessSpecifier FinalAccess;
1350
1351 if (Entity.isMemberAccess()) {
1352 // Determine if the declaration is accessible from EC when named
1353 // in its declaring class.
1354 NamedDecl *Target = Entity.getTargetDecl();
1355 const CXXRecordDecl *DeclaringClass = Entity.getDeclaringClass();
1356
1357 FinalAccess = Target->getAccess();
1358 switch (HasAccess(S, EC, DeclaringClass, FinalAccess, Entity)) {
1359 case AR_accessible:
1360 // Target is accessible at EC when named in its declaring class.
1361 // We can now hill-climb and simply check whether the declaring
1362 // class is accessible as a base of the naming class. This is
1363 // equivalent to checking the access of a notional public
1364 // member with no instance context.
1365 FinalAccess = AS_public;
1366 Entity.suppressInstanceContext();
1367 break;
1368 case AR_inaccessible: break;
1369 case AR_dependent: return AR_dependent; // see above
1370 }
1371
1372 if (DeclaringClass == NamingClass)
1373 return (FinalAccess == AS_public ? AR_accessible : AR_inaccessible);
1374 } else {
1375 FinalAccess = AS_public;
1376 }
1377
1378 assert(Entity.getDeclaringClass() != NamingClass)((Entity.getDeclaringClass() != NamingClass) ? static_cast<
void> (0) : __assert_fail ("Entity.getDeclaringClass() != NamingClass"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1378, __PRETTY_FUNCTION__))
;
1379
1380 // Append the declaration's access if applicable.
1381 CXXBasePaths Paths;
1382 CXXBasePath *Path = FindBestPath(S, EC, Entity, FinalAccess, Paths);
1383 if (!Path)
1384 return AR_dependent;
1385
1386 assert(Path->Access <= UnprivilegedAccess &&((Path->Access <= UnprivilegedAccess && "access along best path worse than direct?"
) ? static_cast<void> (0) : __assert_fail ("Path->Access <= UnprivilegedAccess && \"access along best path worse than direct?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1387, __PRETTY_FUNCTION__))
1387 "access along best path worse than direct?")((Path->Access <= UnprivilegedAccess && "access along best path worse than direct?"
) ? static_cast<void> (0) : __assert_fail ("Path->Access <= UnprivilegedAccess && \"access along best path worse than direct?\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1387, __PRETTY_FUNCTION__))
;
1388 if (Path->Access == AS_public)
1389 return AR_accessible;
1390 return AR_inaccessible;
1391}
1392
1393static void DelayDependentAccess(Sema &S,
1394 const EffectiveContext &EC,
1395 SourceLocation Loc,
1396 const AccessTarget &Entity) {
1397 assert(EC.isDependent() && "delaying non-dependent access")((EC.isDependent() && "delaying non-dependent access"
) ? static_cast<void> (0) : __assert_fail ("EC.isDependent() && \"delaying non-dependent access\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1397, __PRETTY_FUNCTION__))
;
1398 DeclContext *DC = EC.getInnerContext();
1399 assert(DC->isDependentContext() && "delaying non-dependent access")((DC->isDependentContext() && "delaying non-dependent access"
) ? static_cast<void> (0) : __assert_fail ("DC->isDependentContext() && \"delaying non-dependent access\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1399, __PRETTY_FUNCTION__))
;
1400 DependentDiagnostic::Create(S.Context, DC, DependentDiagnostic::Access,
1401 Loc,
1402 Entity.isMemberAccess(),
1403 Entity.getAccess(),
1404 Entity.getTargetDecl(),
1405 Entity.getNamingClass(),
1406 Entity.getBaseObjectType(),
1407 Entity.getDiag());
1408}
1409
1410/// Checks access to an entity from the given effective context.
1411static AccessResult CheckEffectiveAccess(Sema &S,
1412 const EffectiveContext &EC,
1413 SourceLocation Loc,
1414 AccessTarget &Entity) {
1415 assert(Entity.getAccess() != AS_public && "called for public access!")((Entity.getAccess() != AS_public && "called for public access!"
) ? static_cast<void> (0) : __assert_fail ("Entity.getAccess() != AS_public && \"called for public access!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1415, __PRETTY_FUNCTION__))
;
1416
1417 switch (IsAccessible(S, EC, Entity)) {
11
Control jumps to 'case AR_inaccessible:' at line 1422
1418 case AR_dependent:
1419 DelayDependentAccess(S, EC, Loc, Entity);
1420 return AR_dependent;
1421
1422 case AR_inaccessible:
1423 if (S.getLangOpts().MSVCCompat &&
12
Assuming the condition is false
1424 IsMicrosoftUsingDeclarationAccessBug(S, Loc, Entity))
1425 return AR_accessible;
1426 if (!Entity.isQuiet())
13
Taking true branch
1427 DiagnoseBadAccess(S, Loc, EC, Entity);
14
Calling 'DiagnoseBadAccess'
1428 return AR_inaccessible;
1429
1430 case AR_accessible:
1431 return AR_accessible;
1432 }
1433
1434 // silence unnecessary warning
1435 llvm_unreachable("invalid access result")::llvm::llvm_unreachable_internal("invalid access result", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1435)
;
1436}
1437
1438static Sema::AccessResult CheckAccess(Sema &S, SourceLocation Loc,
1439 AccessTarget &Entity) {
1440 // If the access path is public, it's accessible everywhere.
1441 if (Entity.getAccess() == AS_public)
1442 return Sema::AR_accessible;
1443
1444 // If we're currently parsing a declaration, we may need to delay
1445 // access control checking, because our effective context might be
1446 // different based on what the declaration comes out as.
1447 //
1448 // For example, we might be parsing a declaration with a scope
1449 // specifier, like this:
1450 // A::private_type A::foo() { ... }
1451 //
1452 // Or we might be parsing something that will turn out to be a friend:
1453 // void foo(A::private_type);
1454 // void B::foo(A::private_type);
1455 if (S.DelayedDiagnostics.shouldDelayDiagnostics()) {
1456 S.DelayedDiagnostics.add(DelayedDiagnostic::makeAccess(Loc, Entity));
1457 return Sema::AR_delayed;
1458 }
1459
1460 EffectiveContext EC(S.CurContext);
1461 switch (CheckEffectiveAccess(S, EC, Loc, Entity)) {
1462 case AR_accessible: return Sema::AR_accessible;
1463 case AR_inaccessible: return Sema::AR_inaccessible;
1464 case AR_dependent: return Sema::AR_dependent;
1465 }
1466 llvm_unreachable("invalid access result")::llvm::llvm_unreachable_internal("invalid access result", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1466)
;
1467}
1468
1469void Sema::HandleDelayedAccessCheck(DelayedDiagnostic &DD, Decl *D) {
1470 // Access control for names used in the declarations of functions
1471 // and function templates should normally be evaluated in the context
1472 // of the declaration, just in case it's a friend of something.
1473 // However, this does not apply to local extern declarations.
1474
1475 DeclContext *DC = D->getDeclContext();
1476 if (D->isLocalExternDecl()) {
1477 DC = D->getLexicalDeclContext();
1478 } else if (FunctionDecl *FN = dyn_cast<FunctionDecl>(D)) {
1479 DC = FN;
1480 } else if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) {
1481 DC = cast<DeclContext>(TD->getTemplatedDecl());
1482 }
1483
1484 EffectiveContext EC(DC);
1485
1486 AccessTarget Target(DD.getAccessData());
1487
1488 if (CheckEffectiveAccess(*this, EC, DD.Loc, Target) == ::AR_inaccessible)
1489 DD.Triggered = true;
1490}
1491
1492void Sema::HandleDependentAccessCheck(const DependentDiagnostic &DD,
1493 const MultiLevelTemplateArgumentList &TemplateArgs) {
1494 SourceLocation Loc = DD.getAccessLoc();
1495 AccessSpecifier Access = DD.getAccess();
1496
1497 Decl *NamingD = FindInstantiatedDecl(Loc, DD.getAccessNamingClass(),
1498 TemplateArgs);
1499 if (!NamingD) return;
1500 Decl *TargetD = FindInstantiatedDecl(Loc, DD.getAccessTarget(),
1501 TemplateArgs);
1502 if (!TargetD) return;
1503
1504 if (DD.isAccessToMember()) {
1505 CXXRecordDecl *NamingClass = cast<CXXRecordDecl>(NamingD);
1506 NamedDecl *TargetDecl = cast<NamedDecl>(TargetD);
1507 QualType BaseObjectType = DD.getAccessBaseObjectType();
1508 if (!BaseObjectType.isNull()) {
1509 BaseObjectType = SubstType(BaseObjectType, TemplateArgs, Loc,
1510 DeclarationName());
1511 if (BaseObjectType.isNull()) return;
1512 }
1513
1514 AccessTarget Entity(Context,
1515 AccessTarget::Member,
1516 NamingClass,
1517 DeclAccessPair::make(TargetDecl, Access),
1518 BaseObjectType);
1519 Entity.setDiag(DD.getDiagnostic());
1520 CheckAccess(*this, Loc, Entity);
1521 } else {
1522 AccessTarget Entity(Context,
1523 AccessTarget::Base,
1524 cast<CXXRecordDecl>(TargetD),
1525 cast<CXXRecordDecl>(NamingD),
1526 Access);
1527 Entity.setDiag(DD.getDiagnostic());
1528 CheckAccess(*this, Loc, Entity);
1529 }
1530}
1531
1532Sema::AccessResult Sema::CheckUnresolvedLookupAccess(UnresolvedLookupExpr *E,
1533 DeclAccessPair Found) {
1534 if (!getLangOpts().AccessControl ||
1535 !E->getNamingClass() ||
1536 Found.getAccess() == AS_public)
1537 return AR_accessible;
1538
1539 AccessTarget Entity(Context, AccessTarget::Member, E->getNamingClass(),
1540 Found, QualType());
1541 Entity.setDiag(diag::err_access) << E->getSourceRange();
1542
1543 return CheckAccess(*this, E->getNameLoc(), Entity);
1544}
1545
1546/// Perform access-control checking on a previously-unresolved member
1547/// access which has now been resolved to a member.
1548Sema::AccessResult Sema::CheckUnresolvedMemberAccess(UnresolvedMemberExpr *E,
1549 DeclAccessPair Found) {
1550 if (!getLangOpts().AccessControl ||
1551 Found.getAccess() == AS_public)
1552 return AR_accessible;
1553
1554 QualType BaseType = E->getBaseType();
1555 if (E->isArrow())
1556 BaseType = BaseType->getAs<PointerType>()->getPointeeType();
1557
1558 AccessTarget Entity(Context, AccessTarget::Member, E->getNamingClass(),
1559 Found, BaseType);
1560 Entity.setDiag(diag::err_access) << E->getSourceRange();
1561
1562 return CheckAccess(*this, E->getMemberLoc(), Entity);
1563}
1564
1565/// Is the given special member function accessible for the purposes of
1566/// deciding whether to define a special member function as deleted?
1567bool Sema::isSpecialMemberAccessibleForDeletion(CXXMethodDecl *decl,
1568 AccessSpecifier access,
1569 QualType objectType) {
1570 // Fast path.
1571 if (access == AS_public || !getLangOpts().AccessControl) return true;
1572
1573 AccessTarget entity(Context, AccessTarget::Member, decl->getParent(),
1574 DeclAccessPair::make(decl, access), objectType);
1575
1576 // Suppress diagnostics.
1577 entity.setDiag(PDiag());
1578
1579 switch (CheckAccess(*this, SourceLocation(), entity)) {
1580 case AR_accessible: return true;
1581 case AR_inaccessible: return false;
1582 case AR_dependent: llvm_unreachable("dependent for =delete computation")::llvm::llvm_unreachable_internal("dependent for =delete computation"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1582)
;
1583 case AR_delayed: llvm_unreachable("cannot delay =delete computation")::llvm::llvm_unreachable_internal("cannot delay =delete computation"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1583)
;
1584 }
1585 llvm_unreachable("bad access result")::llvm::llvm_unreachable_internal("bad access result", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1585)
;
1586}
1587
1588Sema::AccessResult Sema::CheckDestructorAccess(SourceLocation Loc,
1589 CXXDestructorDecl *Dtor,
1590 const PartialDiagnostic &PDiag,
1591 QualType ObjectTy) {
1592 if (!getLangOpts().AccessControl)
1593 return AR_accessible;
1594
1595 // There's never a path involved when checking implicit destructor access.
1596 AccessSpecifier Access = Dtor->getAccess();
1597 if (Access == AS_public)
1598 return AR_accessible;
1599
1600 CXXRecordDecl *NamingClass = Dtor->getParent();
1601 if (ObjectTy.isNull()) ObjectTy = Context.getTypeDeclType(NamingClass);
1602
1603 AccessTarget Entity(Context, AccessTarget::Member, NamingClass,
1604 DeclAccessPair::make(Dtor, Access),
1605 ObjectTy);
1606 Entity.setDiag(PDiag); // TODO: avoid copy
1607
1608 return CheckAccess(*this, Loc, Entity);
1609}
1610
1611/// Checks access to a constructor.
1612Sema::AccessResult Sema::CheckConstructorAccess(SourceLocation UseLoc,
1613 CXXConstructorDecl *Constructor,
1614 DeclAccessPair Found,
1615 const InitializedEntity &Entity,
1616 bool IsCopyBindingRefToTemp) {
1617 if (!getLangOpts().AccessControl || Found.getAccess() == AS_public)
1618 return AR_accessible;
1619
1620 PartialDiagnostic PD(PDiag());
1621 switch (Entity.getKind()) {
1622 default:
1623 PD = PDiag(IsCopyBindingRefToTemp
1624 ? diag::ext_rvalue_to_reference_access_ctor
1625 : diag::err_access_ctor);
1626
1627 break;
1628
1629 case InitializedEntity::EK_Base:
1630 PD = PDiag(diag::err_access_base_ctor);
1631 PD << Entity.isInheritedVirtualBase()
1632 << Entity.getBaseSpecifier()->getType() << getSpecialMember(Constructor);
1633 break;
1634
1635 case InitializedEntity::EK_Member: {
1636 const FieldDecl *Field = cast<FieldDecl>(Entity.getDecl());
1637 PD = PDiag(diag::err_access_field_ctor);
1638 PD << Field->getType() << getSpecialMember(Constructor);
1639 break;
1640 }
1641
1642 case InitializedEntity::EK_LambdaCapture: {
1643 StringRef VarName = Entity.getCapturedVarName();
1644 PD = PDiag(diag::err_access_lambda_capture);
1645 PD << VarName << Entity.getType() << getSpecialMember(Constructor);
1646 break;
1647 }
1648
1649 }
1650
1651 return CheckConstructorAccess(UseLoc, Constructor, Found, Entity, PD);
1652}
1653
1654/// Checks access to a constructor.
1655Sema::AccessResult Sema::CheckConstructorAccess(SourceLocation UseLoc,
1656 CXXConstructorDecl *Constructor,
1657 DeclAccessPair Found,
1658 const InitializedEntity &Entity,
1659 const PartialDiagnostic &PD) {
1660 if (!getLangOpts().AccessControl ||
1661 Found.getAccess() == AS_public)
1662 return AR_accessible;
1663
1664 CXXRecordDecl *NamingClass = Constructor->getParent();
1665
1666 // Initializing a base sub-object is an instance method call on an
1667 // object of the derived class. Otherwise, we have an instance method
1668 // call on an object of the constructed type.
1669 //
1670 // FIXME: If we have a parent, we're initializing the base class subobject
1671 // in aggregate initialization. It's not clear whether the object class
1672 // should be the base class or the derived class in that case.
1673 CXXRecordDecl *ObjectClass;
1674 if ((Entity.getKind() == InitializedEntity::EK_Base ||
1675 Entity.getKind() == InitializedEntity::EK_Delegating) &&
1676 !Entity.getParent()) {
1677 ObjectClass = cast<CXXConstructorDecl>(CurContext)->getParent();
1678 } else if (auto *Shadow =
1679 dyn_cast<ConstructorUsingShadowDecl>(Found.getDecl())) {
1680 // If we're using an inheriting constructor to construct an object,
1681 // the object class is the derived class, not the base class.
1682 ObjectClass = Shadow->getParent();
1683 } else {
1684 ObjectClass = NamingClass;
1685 }
1686
1687 AccessTarget AccessEntity(
1688 Context, AccessTarget::Member, NamingClass,
1689 DeclAccessPair::make(Constructor, Found.getAccess()),
1690 Context.getTypeDeclType(ObjectClass));
1691 AccessEntity.setDiag(PD);
1692
1693 return CheckAccess(*this, UseLoc, AccessEntity);
1694}
1695
1696/// Checks access to an overloaded operator new or delete.
1697Sema::AccessResult Sema::CheckAllocationAccess(SourceLocation OpLoc,
1698 SourceRange PlacementRange,
1699 CXXRecordDecl *NamingClass,
1700 DeclAccessPair Found,
1701 bool Diagnose) {
1702 if (!getLangOpts().AccessControl ||
1703 !NamingClass ||
1704 Found.getAccess() == AS_public)
1705 return AR_accessible;
1706
1707 AccessTarget Entity(Context, AccessTarget::Member, NamingClass, Found,
1708 QualType());
1709 if (Diagnose)
1710 Entity.setDiag(diag::err_access)
1711 << PlacementRange;
1712
1713 return CheckAccess(*this, OpLoc, Entity);
1714}
1715
1716/// Checks access to a member.
1717Sema::AccessResult Sema::CheckMemberAccess(SourceLocation UseLoc,
1718 CXXRecordDecl *NamingClass,
1719 DeclAccessPair Found) {
1720 if (!getLangOpts().AccessControl ||
1721 !NamingClass ||
1722 Found.getAccess() == AS_public)
1723 return AR_accessible;
1724
1725 AccessTarget Entity(Context, AccessTarget::Member, NamingClass,
1726 Found, QualType());
1727
1728 return CheckAccess(*this, UseLoc, Entity);
1729}
1730
1731/// Checks implicit access to a member in a structured binding.
1732Sema::AccessResult
1733Sema::CheckStructuredBindingMemberAccess(SourceLocation UseLoc,
1734 CXXRecordDecl *DecomposedClass,
1735 DeclAccessPair Field) {
1736 if (!getLangOpts().AccessControl ||
1737 Field.getAccess() == AS_public)
1738 return AR_accessible;
1739
1740 AccessTarget Entity(Context, AccessTarget::Member, DecomposedClass, Field,
1741 Context.getRecordType(DecomposedClass));
1742 Entity.setDiag(diag::err_decomp_decl_inaccessible_field);
1743
1744 return CheckAccess(*this, UseLoc, Entity);
1745}
1746
1747/// Checks access to an overloaded member operator, including
1748/// conversion operators.
1749Sema::AccessResult Sema::CheckMemberOperatorAccess(SourceLocation OpLoc,
1750 Expr *ObjectExpr,
1751 Expr *ArgExpr,
1752 DeclAccessPair Found) {
1753 if (!getLangOpts().AccessControl ||
1754 Found.getAccess() == AS_public)
1755 return AR_accessible;
1756
1757 const RecordType *RT = ObjectExpr->getType()->castAs<RecordType>();
1758 CXXRecordDecl *NamingClass = cast<CXXRecordDecl>(RT->getDecl());
1759
1760 AccessTarget Entity(Context, AccessTarget::Member, NamingClass, Found,
1761 ObjectExpr->getType());
1762 Entity.setDiag(diag::err_access)
1763 << ObjectExpr->getSourceRange()
1764 << (ArgExpr ? ArgExpr->getSourceRange() : SourceRange());
1765
1766 return CheckAccess(*this, OpLoc, Entity);
1767}
1768
1769/// Checks access to the target of a friend declaration.
1770Sema::AccessResult Sema::CheckFriendAccess(NamedDecl *target) {
1771 assert(isa<CXXMethodDecl>(target->getAsFunction()))((isa<CXXMethodDecl>(target->getAsFunction())) ? static_cast
<void> (0) : __assert_fail ("isa<CXXMethodDecl>(target->getAsFunction())"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1771, __PRETTY_FUNCTION__))
;
1772
1773 // Friendship lookup is a redeclaration lookup, so there's never an
1774 // inheritance path modifying access.
1775 AccessSpecifier access = target->getAccess();
1776
1777 if (!getLangOpts().AccessControl || access == AS_public)
1778 return AR_accessible;
1779
1780 CXXMethodDecl *method = cast<CXXMethodDecl>(target->getAsFunction());
1781
1782 AccessTarget entity(Context, AccessTarget::Member,
1783 cast<CXXRecordDecl>(target->getDeclContext()),
1784 DeclAccessPair::make(target, access),
1785 /*no instance context*/ QualType());
1786 entity.setDiag(diag::err_access_friend_function)
1787 << (method->getQualifier() ? method->getQualifierLoc().getSourceRange()
1788 : method->getNameInfo().getSourceRange());
1789
1790 // We need to bypass delayed-diagnostics because we might be called
1791 // while the ParsingDeclarator is active.
1792 EffectiveContext EC(CurContext);
1793 switch (CheckEffectiveAccess(*this, EC, target->getLocation(), entity)) {
1794 case ::AR_accessible: return Sema::AR_accessible;
1795 case ::AR_inaccessible: return Sema::AR_inaccessible;
1796 case ::AR_dependent: return Sema::AR_dependent;
1797 }
1798 llvm_unreachable("invalid access result")::llvm::llvm_unreachable_internal("invalid access result", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1798)
;
1799}
1800
1801Sema::AccessResult Sema::CheckAddressOfMemberAccess(Expr *OvlExpr,
1802 DeclAccessPair Found) {
1803 if (!getLangOpts().AccessControl ||
1804 Found.getAccess() == AS_none ||
1805 Found.getAccess() == AS_public)
1806 return AR_accessible;
1807
1808 OverloadExpr *Ovl = OverloadExpr::find(OvlExpr).Expression;
1809 CXXRecordDecl *NamingClass = Ovl->getNamingClass();
1810
1811 AccessTarget Entity(Context, AccessTarget::Member, NamingClass, Found,
1812 /*no instance context*/ QualType());
1813 Entity.setDiag(diag::err_access)
1814 << Ovl->getSourceRange();
1815
1816 return CheckAccess(*this, Ovl->getNameLoc(), Entity);
1817}
1818
1819/// Checks access for a hierarchy conversion.
1820///
1821/// \param ForceCheck true if this check should be performed even if access
1822/// control is disabled; some things rely on this for semantics
1823/// \param ForceUnprivileged true if this check should proceed as if the
1824/// context had no special privileges
1825Sema::AccessResult Sema::CheckBaseClassAccess(SourceLocation AccessLoc,
1826 QualType Base,
1827 QualType Derived,
1828 const CXXBasePath &Path,
1829 unsigned DiagID,
1830 bool ForceCheck,
1831 bool ForceUnprivileged) {
1832 if (!ForceCheck && !getLangOpts().AccessControl)
1
Assuming 'ForceCheck' is 0
2
Assuming the condition is false
3
Taking false branch
1833 return AR_accessible;
1834
1835 if (Path.Access == AS_public)
4
Assuming the condition is false
5
Taking false branch
1836 return AR_accessible;
1837
1838 CXXRecordDecl *BaseD, *DerivedD;
1839 BaseD = cast<CXXRecordDecl>(Base->getAs<RecordType>()->getDecl());
1840 DerivedD = cast<CXXRecordDecl>(Derived->getAs<RecordType>()->getDecl());
1841
1842 AccessTarget Entity(Context, AccessTarget::Base, BaseD, DerivedD,
1843 Path.Access);
1844 if (DiagID)
6
Assuming 'DiagID' is 0
7
Taking false branch
1845 Entity.setDiag(DiagID) << Derived << Base;
1846
1847 if (ForceUnprivileged) {
8
Assuming 'ForceUnprivileged' is not equal to 0
9
Taking true branch
1848 switch (CheckEffectiveAccess(*this, EffectiveContext(),
10
Calling 'CheckEffectiveAccess'
1849 AccessLoc, Entity)) {
1850 case ::AR_accessible: return Sema::AR_accessible;
1851 case ::AR_inaccessible: return Sema::AR_inaccessible;
1852 case ::AR_dependent: return Sema::AR_dependent;
1853 }
1854 llvm_unreachable("unexpected result from CheckEffectiveAccess")::llvm::llvm_unreachable_internal("unexpected result from CheckEffectiveAccess"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1854)
;
1855 }
1856 return CheckAccess(*this, AccessLoc, Entity);
1857}
1858
1859/// Checks access to all the declarations in the given result set.
1860void Sema::CheckLookupAccess(const LookupResult &R) {
1861 assert(getLangOpts().AccessControl((getLangOpts().AccessControl && "performing access check without access control"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().AccessControl && \"performing access check without access control\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1862, __PRETTY_FUNCTION__))
1862 && "performing access check without access control")((getLangOpts().AccessControl && "performing access check without access control"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().AccessControl && \"performing access check without access control\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1862, __PRETTY_FUNCTION__))
;
1863 assert(R.getNamingClass() && "performing access check without naming class")((R.getNamingClass() && "performing access check without naming class"
) ? static_cast<void> (0) : __assert_fail ("R.getNamingClass() && \"performing access check without naming class\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/lib/Sema/SemaAccess.cpp"
, 1863, __PRETTY_FUNCTION__))
;
1864
1865 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
1866 if (I.getAccess() != AS_public) {
1867 AccessTarget Entity(Context, AccessedEntity::Member,
1868 R.getNamingClass(), I.getPair(),
1869 R.getBaseObjectType());
1870 Entity.setDiag(diag::err_access);
1871 CheckAccess(*this, R.getNameLoc(), Entity);
1872 }
1873 }
1874}
1875
1876/// Checks access to Target from the given class. The check will take access
1877/// specifiers into account, but no member access expressions and such.
1878///
1879/// \param Target the declaration to check if it can be accessed
1880/// \param Ctx the class/context from which to start the search
1881/// \return true if the Target is accessible from the Class, false otherwise.
1882bool Sema::IsSimplyAccessible(NamedDecl *Target, DeclContext *Ctx) {
1883 if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) {
1884 if (!Target->isCXXClassMember())
1885 return true;
1886
1887 if (Target->getAccess() == AS_public)
1888 return true;
1889 QualType qType = Class->getTypeForDecl()->getCanonicalTypeInternal();
1890 // The unprivileged access is AS_none as we don't know how the member was
1891 // accessed, which is described by the access in DeclAccessPair.
1892 // `IsAccessible` will examine the actual access of Target (i.e.
1893 // Decl->getAccess()) when calculating the access.
1894 AccessTarget Entity(Context, AccessedEntity::Member, Class,
1895 DeclAccessPair::make(Target, AS_none), qType);
1896 EffectiveContext EC(CurContext);
1897 return ::IsAccessible(*this, EC, Entity) != ::AR_inaccessible;
1898 }
1899
1900 if (ObjCIvarDecl *Ivar = dyn_cast<ObjCIvarDecl>(Target)) {
1901 // @public and @package ivars are always accessible.
1902 if (Ivar->getCanonicalAccessControl() == ObjCIvarDecl::Public ||
1903 Ivar->getCanonicalAccessControl() == ObjCIvarDecl::Package)
1904 return true;
1905
1906 // If we are inside a class or category implementation, determine the
1907 // interface we're in.
1908 ObjCInterfaceDecl *ClassOfMethodDecl = nullptr;
1909 if (ObjCMethodDecl *MD = getCurMethodDecl())
1910 ClassOfMethodDecl = MD->getClassInterface();
1911 else if (FunctionDecl *FD = getCurFunctionDecl()) {
1912 if (ObjCImplDecl *Impl
1913 = dyn_cast<ObjCImplDecl>(FD->getLexicalDeclContext())) {
1914 if (ObjCImplementationDecl *IMPD
1915 = dyn_cast<ObjCImplementationDecl>(Impl))
1916 ClassOfMethodDecl = IMPD->getClassInterface();
1917 else if (ObjCCategoryImplDecl* CatImplClass
1918 = dyn_cast<ObjCCategoryImplDecl>(Impl))
1919 ClassOfMethodDecl = CatImplClass->getClassInterface();
1920 }
1921 }
1922
1923 // If we're not in an interface, this ivar is inaccessible.
1924 if (!ClassOfMethodDecl)
1925 return false;
1926
1927 // If we're inside the same interface that owns the ivar, we're fine.
1928 if (declaresSameEntity(ClassOfMethodDecl, Ivar->getContainingInterface()))
1929 return true;
1930
1931 // If the ivar is private, it's inaccessible.
1932 if (Ivar->getCanonicalAccessControl() == ObjCIvarDecl::Private)
1933 return false;
1934
1935 return Ivar->getContainingInterface()->isSuperClassOf(ClassOfMethodDecl);
1936 }
1937
1938 return true;
1939}