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llvm-project/clang/lib/Sema/SemaAccess.cpp

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//===---- SemaAccess.cpp - C++ Access Control -------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides Sema routines for C++ access control semantics.
//
//===----------------------------------------------------------------------===//
#include "clang/Sema/SemaInternal.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclFriend.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DependentDiagnostic.h"
#include "clang/AST/ExprCXX.h"
#include "clang/Sema/DelayedDiagnostic.h"
#include "clang/Sema/Initialization.h"
#include "clang/Sema/Lookup.h"
using namespace clang;
using namespace sema;
/// A copy of Sema's enum without AR_delayed.
enum AccessResult {
AR_accessible,
AR_inaccessible,
AR_dependent
};
/// SetMemberAccessSpecifier - Set the access specifier of a member.
/// Returns true on error (when the previous member decl access specifier
/// is different from the new member decl access specifier).
bool Sema::SetMemberAccessSpecifier(NamedDecl *MemberDecl,
NamedDecl *PrevMemberDecl,
AccessSpecifier LexicalAS) {
if (!PrevMemberDecl) {
// Use the lexical access specifier.
MemberDecl->setAccess(LexicalAS);
return false;
}
// C++ [class.access.spec]p3: When a member is redeclared its access
// specifier must be same as its initial declaration.
if (LexicalAS != AS_none && LexicalAS != PrevMemberDecl->getAccess()) {
Diag(MemberDecl->getLocation(),
diag::err_class_redeclared_with_different_access)
<< MemberDecl << LexicalAS;
Diag(PrevMemberDecl->getLocation(), diag::note_previous_access_declaration)
<< PrevMemberDecl << PrevMemberDecl->getAccess();
MemberDecl->setAccess(LexicalAS);
return true;
}
MemberDecl->setAccess(PrevMemberDecl->getAccess());
return false;
}
static CXXRecordDecl *FindDeclaringClass(NamedDecl *D) {
DeclContext *DC = D->getDeclContext();
// This can only happen at top: enum decls only "publish" their
// immediate members.
if (isa<EnumDecl>(DC))
DC = cast<EnumDecl>(DC)->getDeclContext();
CXXRecordDecl *DeclaringClass = cast<CXXRecordDecl>(DC);
while (DeclaringClass->isAnonymousStructOrUnion())
DeclaringClass = cast<CXXRecordDecl>(DeclaringClass->getDeclContext());
return DeclaringClass;
}
namespace {
struct EffectiveContext {
EffectiveContext() : Inner(nullptr), Dependent(false) {}
explicit EffectiveContext(DeclContext *DC)
: Inner(DC),
Dependent(DC->isDependentContext()) {
// C++11 [class.access.nest]p1:
// A nested class is a member and as such has the same access
// rights as any other member.
// C++11 [class.access]p2:
// A member of a class can also access all the names to which
// the class has access. A local class of a member function
// may access the same names that the member function itself
// may access.
// This almost implies that the privileges of nesting are transitive.
// Technically it says nothing about the local classes of non-member
// functions (which can gain privileges through friendship), but we
// take that as an oversight.
while (true) {
// We want to add canonical declarations to the EC lists for
// simplicity of checking, but we need to walk up through the
// actual current DC chain. Otherwise, something like a local
// extern or friend which happens to be the canonical
// declaration will really mess us up.
if (isa<CXXRecordDecl>(DC)) {
CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
Records.push_back(Record->getCanonicalDecl());
DC = Record->getDeclContext();
} else if (isa<FunctionDecl>(DC)) {
FunctionDecl *Function = cast<FunctionDecl>(DC);
Functions.push_back(Function->getCanonicalDecl());
if (Function->getFriendObjectKind())
DC = Function->getLexicalDeclContext();
else
DC = Function->getDeclContext();
} else if (DC->isFileContext()) {
break;
} else {
DC = DC->getParent();
}
}
}
bool isDependent() const { return Dependent; }
bool includesClass(const CXXRecordDecl *R) const {
R = R->getCanonicalDecl();
return std::find(Records.begin(), Records.end(), R)
!= Records.end();
}
/// Retrieves the innermost "useful" context. Can be null if we're
/// doing access-control without privileges.
DeclContext *getInnerContext() const {
return Inner;
}
typedef SmallVectorImpl<CXXRecordDecl*>::const_iterator record_iterator;
DeclContext *Inner;
SmallVector<FunctionDecl*, 4> Functions;
SmallVector<CXXRecordDecl*, 4> Records;
bool Dependent;
};
/// Like sema::AccessedEntity, but kindly lets us scribble all over
/// it.
struct AccessTarget : public AccessedEntity {
AccessTarget(const AccessedEntity &Entity)
: AccessedEntity(Entity) {
initialize();
}
AccessTarget(ASTContext &Context,
MemberNonce _,
CXXRecordDecl *NamingClass,
DeclAccessPair FoundDecl,
QualType BaseObjectType)
: AccessedEntity(Context.getDiagAllocator(), Member, NamingClass,
FoundDecl, BaseObjectType) {
initialize();
}
AccessTarget(ASTContext &Context,
BaseNonce _,
CXXRecordDecl *BaseClass,
CXXRecordDecl *DerivedClass,
AccessSpecifier Access)
: AccessedEntity(Context.getDiagAllocator(), Base, BaseClass, DerivedClass,
Access) {
initialize();
}
bool isInstanceMember() const {
return (isMemberAccess() && getTargetDecl()->isCXXInstanceMember());
}
bool hasInstanceContext() const {
return HasInstanceContext;
}
class SavedInstanceContext {
public:
~SavedInstanceContext() {
Target.HasInstanceContext = Has;
}
private:
friend struct AccessTarget;
explicit SavedInstanceContext(AccessTarget &Target)
: Target(Target), Has(Target.HasInstanceContext) {}
AccessTarget &Target;
bool Has;
};
SavedInstanceContext saveInstanceContext() {
return SavedInstanceContext(*this);
}
void suppressInstanceContext() {
HasInstanceContext = false;
}
const CXXRecordDecl *resolveInstanceContext(Sema &S) const {
assert(HasInstanceContext);
if (CalculatedInstanceContext)
return InstanceContext;
CalculatedInstanceContext = true;
DeclContext *IC = S.computeDeclContext(getBaseObjectType());
InstanceContext = (IC ? cast<CXXRecordDecl>(IC)->getCanonicalDecl()
: nullptr);
return InstanceContext;
}
const CXXRecordDecl *getDeclaringClass() const {
return DeclaringClass;
}
/// The "effective" naming class is the canonical non-anonymous
/// class containing the actual naming class.
const CXXRecordDecl *getEffectiveNamingClass() const {
const CXXRecordDecl *namingClass = getNamingClass();
while (namingClass->isAnonymousStructOrUnion())
namingClass = cast<CXXRecordDecl>(namingClass->getParent());
return namingClass->getCanonicalDecl();
}
private:
void initialize() {
HasInstanceContext = (isMemberAccess() &&
!getBaseObjectType().isNull() &&
getTargetDecl()->isCXXInstanceMember());
CalculatedInstanceContext = false;
InstanceContext = nullptr;
if (isMemberAccess())
DeclaringClass = FindDeclaringClass(getTargetDecl());
else
DeclaringClass = getBaseClass();
DeclaringClass = DeclaringClass->getCanonicalDecl();
}
bool HasInstanceContext : 1;
mutable bool CalculatedInstanceContext : 1;
mutable const CXXRecordDecl *InstanceContext;
const CXXRecordDecl *DeclaringClass;
};
}
/// Checks whether one class might instantiate to the other.
static bool MightInstantiateTo(const CXXRecordDecl *From,
const CXXRecordDecl *To) {
// Declaration names are always preserved by instantiation.
if (From->getDeclName() != To->getDeclName())
return false;
const DeclContext *FromDC = From->getDeclContext()->getPrimaryContext();
const DeclContext *ToDC = To->getDeclContext()->getPrimaryContext();
if (FromDC == ToDC) return true;
if (FromDC->isFileContext() || ToDC->isFileContext()) return false;
// Be conservative.
return true;
}
/// Checks whether one class is derived from another, inclusively.
/// Properly indicates when it couldn't be determined due to
/// dependence.
///
/// This should probably be donated to AST or at least Sema.
static AccessResult IsDerivedFromInclusive(const CXXRecordDecl *Derived,
const CXXRecordDecl *Target) {
assert(Derived->getCanonicalDecl() == Derived);
assert(Target->getCanonicalDecl() == Target);
if (Derived == Target) return AR_accessible;
bool CheckDependent = Derived->isDependentContext();
if (CheckDependent && MightInstantiateTo(Derived, Target))
return AR_dependent;
AccessResult OnFailure = AR_inaccessible;
SmallVector<const CXXRecordDecl*, 8> Queue; // actually a stack
while (true) {
if (Derived->isDependentContext() && !Derived->hasDefinition())
return AR_dependent;
for (const auto &I : Derived->bases()) {
const CXXRecordDecl *RD;
QualType T = I.getType();
if (const RecordType *RT = T->getAs<RecordType>()) {
RD = cast<CXXRecordDecl>(RT->getDecl());
} else if (const InjectedClassNameType *IT
= T->getAs<InjectedClassNameType>()) {
RD = IT->getDecl();
} else {
assert(T->isDependentType() && "non-dependent base wasn't a record?");
OnFailure = AR_dependent;
continue;
}
RD = RD->getCanonicalDecl();
if (RD == Target) return AR_accessible;
if (CheckDependent && MightInstantiateTo(RD, Target))
OnFailure = AR_dependent;
Queue.push_back(RD);
}
if (Queue.empty()) break;
Derived = Queue.pop_back_val();
}
return OnFailure;
}
static bool MightInstantiateTo(Sema &S, DeclContext *Context,
DeclContext *Friend) {
if (Friend == Context)
return true;
assert(!Friend->isDependentContext() &&
"can't handle friends with dependent contexts here");
if (!Context->isDependentContext())
return false;
if (Friend->isFileContext())
return false;
// TODO: this is very conservative
return true;
}
// Asks whether the type in 'context' can ever instantiate to the type
// in 'friend'.
static bool MightInstantiateTo(Sema &S, CanQualType Context, CanQualType Friend) {
if (Friend == Context)
return true;
if (!Friend->isDependentType() && !Context->isDependentType())
return false;
// TODO: this is very conservative.
return true;
}
static bool MightInstantiateTo(Sema &S,
FunctionDecl *Context,
FunctionDecl *Friend) {
if (Context->getDeclName() != Friend->getDeclName())
return false;
if (!MightInstantiateTo(S,
Context->getDeclContext(),
Friend->getDeclContext()))
return false;
CanQual<FunctionProtoType> FriendTy
= S.Context.getCanonicalType(Friend->getType())
->getAs<FunctionProtoType>();
CanQual<FunctionProtoType> ContextTy
= S.Context.getCanonicalType(Context->getType())
->getAs<FunctionProtoType>();
// There isn't any way that I know of to add qualifiers
// during instantiation.
if (FriendTy.getQualifiers() != ContextTy.getQualifiers())
return false;
if (FriendTy->getNumParams() != ContextTy->getNumParams())
return false;
if (!MightInstantiateTo(S, ContextTy->getReturnType(),
FriendTy->getReturnType()))
return false;
for (unsigned I = 0, E = FriendTy->getNumParams(); I != E; ++I)
if (!MightInstantiateTo(S, ContextTy->getParamType(I),
FriendTy->getParamType(I)))
return false;
return true;
}
static bool MightInstantiateTo(Sema &S,
FunctionTemplateDecl *Context,
FunctionTemplateDecl *Friend) {
return MightInstantiateTo(S,
Context->getTemplatedDecl(),
Friend->getTemplatedDecl());
}
static AccessResult MatchesFriend(Sema &S,
const EffectiveContext &EC,
const CXXRecordDecl *Friend) {
if (EC.includesClass(Friend))
return AR_accessible;
if (EC.isDependent()) {
CanQualType FriendTy
= S.Context.getCanonicalType(S.Context.getTypeDeclType(Friend));
for (EffectiveContext::record_iterator
I = EC.Records.begin(), E = EC.Records.end(); I != E; ++I) {
CanQualType ContextTy
= S.Context.getCanonicalType(S.Context.getTypeDeclType(*I));
if (MightInstantiateTo(S, ContextTy, FriendTy))
return AR_dependent;
}
}
return AR_inaccessible;
}
static AccessResult MatchesFriend(Sema &S,
const EffectiveContext &EC,
CanQualType Friend) {
if (const RecordType *RT = Friend->getAs<RecordType>())
return MatchesFriend(S, EC, cast<CXXRecordDecl>(RT->getDecl()));
// TODO: we can do better than this
if (Friend->isDependentType())
return AR_dependent;
return AR_inaccessible;
}
/// Determines whether the given friend class template matches
/// anything in the effective context.
static AccessResult MatchesFriend(Sema &S,
const EffectiveContext &EC,
ClassTemplateDecl *Friend) {
AccessResult OnFailure = AR_inaccessible;
// Check whether the friend is the template of a class in the
// context chain.
for (SmallVectorImpl<CXXRecordDecl*>::const_iterator
I = EC.Records.begin(), E = EC.Records.end(); I != E; ++I) {
CXXRecordDecl *Record = *I;
// Figure out whether the current class has a template:
ClassTemplateDecl *CTD;
// A specialization of the template...
if (isa<ClassTemplateSpecializationDecl>(Record)) {
CTD = cast<ClassTemplateSpecializationDecl>(Record)
->getSpecializedTemplate();
// ... or the template pattern itself.
} else {
CTD = Record->getDescribedClassTemplate();
if (!CTD) continue;
}
// It's a match.
if (Friend == CTD->getCanonicalDecl())
return AR_accessible;
// If the context isn't dependent, it can't be a dependent match.
if (!EC.isDependent())
continue;
// If the template names don't match, it can't be a dependent
// match.
if (CTD->getDeclName() != Friend->getDeclName())
continue;
// If the class's context can't instantiate to the friend's
// context, it can't be a dependent match.
if (!MightInstantiateTo(S, CTD->getDeclContext(),
Friend->getDeclContext()))
continue;
// Otherwise, it's a dependent match.
OnFailure = AR_dependent;
}
return OnFailure;
}
/// Determines whether the given friend function matches anything in
/// the effective context.
static AccessResult MatchesFriend(Sema &S,
const EffectiveContext &EC,
FunctionDecl *Friend) {
AccessResult OnFailure = AR_inaccessible;
for (SmallVectorImpl<FunctionDecl*>::const_iterator
I = EC.Functions.begin(), E = EC.Functions.end(); I != E; ++I) {
if (Friend == *I)
return AR_accessible;
if (EC.isDependent() && MightInstantiateTo(S, *I, Friend))
OnFailure = AR_dependent;
}
return OnFailure;
}
/// Determines whether the given friend function template matches
/// anything in the effective context.
static AccessResult MatchesFriend(Sema &S,
const EffectiveContext &EC,
FunctionTemplateDecl *Friend) {
if (EC.Functions.empty()) return AR_inaccessible;
AccessResult OnFailure = AR_inaccessible;
for (SmallVectorImpl<FunctionDecl*>::const_iterator
I = EC.Functions.begin(), E = EC.Functions.end(); I != E; ++I) {
FunctionTemplateDecl *FTD = (*I)->getPrimaryTemplate();
if (!FTD)
FTD = (*I)->getDescribedFunctionTemplate();
if (!FTD)
continue;
FTD = FTD->getCanonicalDecl();
if (Friend == FTD)
return AR_accessible;
if (EC.isDependent() && MightInstantiateTo(S, FTD, Friend))
OnFailure = AR_dependent;
}
return OnFailure;
}
/// Determines whether the given friend declaration matches anything
/// in the effective context.
static AccessResult MatchesFriend(Sema &S,
const EffectiveContext &EC,
FriendDecl *FriendD) {
// Whitelist accesses if there's an invalid or unsupported friend
// declaration.
if (FriendD->isInvalidDecl() || FriendD->isUnsupportedFriend())
return AR_accessible;
if (TypeSourceInfo *T = FriendD->getFriendType())
return MatchesFriend(S, EC, T->getType()->getCanonicalTypeUnqualified());
NamedDecl *Friend
= cast<NamedDecl>(FriendD->getFriendDecl()->getCanonicalDecl());
// FIXME: declarations with dependent or templated scope.
if (isa<ClassTemplateDecl>(Friend))
return MatchesFriend(S, EC, cast<ClassTemplateDecl>(Friend));
if (isa<FunctionTemplateDecl>(Friend))
return MatchesFriend(S, EC, cast<FunctionTemplateDecl>(Friend));
if (isa<CXXRecordDecl>(Friend))
return MatchesFriend(S, EC, cast<CXXRecordDecl>(Friend));
assert(isa<FunctionDecl>(Friend) && "unknown friend decl kind");
return MatchesFriend(S, EC, cast<FunctionDecl>(Friend));
}
static AccessResult GetFriendKind(Sema &S,
const EffectiveContext &EC,
const CXXRecordDecl *Class) {
AccessResult OnFailure = AR_inaccessible;
// Okay, check friends.
for (auto *Friend : Class->friends()) {
switch (MatchesFriend(S, EC, Friend)) {
case AR_accessible:
return AR_accessible;
case AR_inaccessible:
continue;
case AR_dependent:
OnFailure = AR_dependent;
break;
}
}
// That's it, give up.
return OnFailure;
}
namespace {
/// A helper class for checking for a friend which will grant access
/// to a protected instance member.
struct ProtectedFriendContext {
Sema &S;
const EffectiveContext &EC;
const CXXRecordDecl *NamingClass;
bool CheckDependent;
bool EverDependent;
/// The path down to the current base class.
SmallVector<const CXXRecordDecl*, 20> CurPath;
ProtectedFriendContext(Sema &S, const EffectiveContext &EC,
const CXXRecordDecl *InstanceContext,
const CXXRecordDecl *NamingClass)
: S(S), EC(EC), NamingClass(NamingClass),
CheckDependent(InstanceContext->isDependentContext() ||
NamingClass->isDependentContext()),
EverDependent(false) {}
/// Check classes in the current path for friendship, starting at
/// the given index.
bool checkFriendshipAlongPath(unsigned I) {
assert(I < CurPath.size());
for (unsigned E = CurPath.size(); I != E; ++I) {
switch (GetFriendKind(S, EC, CurPath[I])) {
case AR_accessible: return true;
case AR_inaccessible: continue;
case AR_dependent: EverDependent = true; continue;
}
}
return false;
}
/// Perform a search starting at the given class.
///
/// PrivateDepth is the index of the last (least derived) class
/// along the current path such that a notional public member of
/// the final class in the path would have access in that class.
bool findFriendship(const CXXRecordDecl *Cur, unsigned PrivateDepth) {
// If we ever reach the naming class, check the current path for
// friendship. We can also stop recursing because we obviously
// won't find the naming class there again.
if (Cur == NamingClass)
return checkFriendshipAlongPath(PrivateDepth);
if (CheckDependent && MightInstantiateTo(Cur, NamingClass))
EverDependent = true;
// Recurse into the base classes.
for (const auto &I : Cur->bases()) {
// If this is private inheritance, then a public member of the
// base will not have any access in classes derived from Cur.
unsigned BasePrivateDepth = PrivateDepth;
if (I.getAccessSpecifier() == AS_private)
BasePrivateDepth = CurPath.size() - 1;
const CXXRecordDecl *RD;
QualType T = I.getType();
if (const RecordType *RT = T->getAs<RecordType>()) {
RD = cast<CXXRecordDecl>(RT->getDecl());
} else if (const InjectedClassNameType *IT
= T->getAs<InjectedClassNameType>()) {
RD = IT->getDecl();
} else {
assert(T->isDependentType() && "non-dependent base wasn't a record?");
EverDependent = true;
continue;
}
// Recurse. We don't need to clean up if this returns true.
CurPath.push_back(RD);
if (findFriendship(RD->getCanonicalDecl(), BasePrivateDepth))
return true;
CurPath.pop_back();
}
return false;
}
bool findFriendship(const CXXRecordDecl *Cur) {
assert(CurPath.empty());
CurPath.push_back(Cur);
return findFriendship(Cur, 0);
}
};
}
/// Search for a class P that EC is a friend of, under the constraint
/// InstanceContext <= P
/// if InstanceContext exists, or else
/// NamingClass <= P
/// and with the additional restriction that a protected member of
/// NamingClass would have some natural access in P, which implicitly
/// imposes the constraint that P <= NamingClass.
///
/// This isn't quite the condition laid out in the standard.
/// Instead of saying that a notional protected member of NamingClass
/// would have to have some natural access in P, it says the actual
/// target has to have some natural access in P, which opens up the
/// possibility that the target (which is not necessarily a member
/// of NamingClass) might be more accessible along some path not
/// passing through it. That's really a bad idea, though, because it
/// introduces two problems:
/// - Most importantly, it breaks encapsulation because you can
/// access a forbidden base class's members by directly subclassing
/// it elsewhere.
/// - It also makes access substantially harder to compute because it
/// breaks the hill-climbing algorithm: knowing that the target is
/// accessible in some base class would no longer let you change
/// the question solely to whether the base class is accessible,
/// because the original target might have been more accessible
/// because of crazy subclassing.
/// So we don't implement that.
static AccessResult GetProtectedFriendKind(Sema &S, const EffectiveContext &EC,
const CXXRecordDecl *InstanceContext,
const CXXRecordDecl *NamingClass) {
assert(InstanceContext == nullptr ||
InstanceContext->getCanonicalDecl() == InstanceContext);
assert(NamingClass->getCanonicalDecl() == NamingClass);
// If we don't have an instance context, our constraints give us
// that NamingClass <= P <= NamingClass, i.e. P == NamingClass.
// This is just the usual friendship check.
if (!InstanceContext) return GetFriendKind(S, EC, NamingClass);
ProtectedFriendContext PRC(S, EC, InstanceContext, NamingClass);
if (PRC.findFriendship(InstanceContext)) return AR_accessible;
if (PRC.EverDependent) return AR_dependent;
return AR_inaccessible;
}
static AccessResult HasAccess(Sema &S,
const EffectiveContext &EC,
const CXXRecordDecl *NamingClass,
AccessSpecifier Access,
const AccessTarget &Target) {
assert(NamingClass->getCanonicalDecl() == NamingClass &&
"declaration should be canonicalized before being passed here");
if (Access == AS_public) return AR_accessible;
assert(Access == AS_private || Access == AS_protected);
AccessResult OnFailure = AR_inaccessible;
for (EffectiveContext::record_iterator
I = EC.Records.begin(), E = EC.Records.end(); I != E; ++I) {
// All the declarations in EC have been canonicalized, so pointer
// equality from this point on will work fine.
const CXXRecordDecl *ECRecord = *I;
// [B2] and [M2]
if (Access == AS_private) {
if (ECRecord == NamingClass)
return AR_accessible;
if (EC.isDependent() && MightInstantiateTo(ECRecord, NamingClass))
OnFailure = AR_dependent;
// [B3] and [M3]
} else {
assert(Access == AS_protected);
switch (IsDerivedFromInclusive(ECRecord, NamingClass)) {
case AR_accessible: break;
case AR_inaccessible: continue;
case AR_dependent: OnFailure = AR_dependent; continue;
}
// C++ [class.protected]p1:
// An additional access check beyond those described earlier in
// [class.access] is applied when a non-static data member or
// non-static member function is a protected member of its naming
// class. As described earlier, access to a protected member is
// granted because the reference occurs in a friend or member of
// some class C. If the access is to form a pointer to member,
// the nested-name-specifier shall name C or a class derived from
// C. All other accesses involve a (possibly implicit) object
// expression. In this case, the class of the object expression
// shall be C or a class derived from C.
//
// We interpret this as a restriction on [M3].
// In this part of the code, 'C' is just our context class ECRecord.
// These rules are different if we don't have an instance context.
if (!Target.hasInstanceContext()) {
// If it's not an instance member, these restrictions don't apply.
if (!Target.isInstanceMember()) return AR_accessible;
// If it's an instance member, use the pointer-to-member rule
// that the naming class has to be derived from the effective
// context.
// Emulate a MSVC bug where the creation of pointer-to-member
// to protected member of base class is allowed but only from
// static member functions.
if (S.getLangOpts().MSVCCompat && !EC.Functions.empty())
if (CXXMethodDecl* MD = dyn_cast<CXXMethodDecl>(EC.Functions.front()))
if (MD->isStatic()) return AR_accessible;
// Despite the standard's confident wording, there is a case
// where you can have an instance member that's neither in a
// pointer-to-member expression nor in a member access: when
// it names a field in an unevaluated context that can't be an
// implicit member. Pending clarification, we just apply the
// same naming-class restriction here.
// FIXME: we're probably not correctly adding the
// protected-member restriction when we retroactively convert
// an expression to being evaluated.
// We know that ECRecord derives from NamingClass. The
// restriction says to check whether NamingClass derives from
// ECRecord, but that's not really necessary: two distinct
// classes can't be recursively derived from each other. So
// along this path, we just need to check whether the classes
// are equal.
if (NamingClass == ECRecord) return AR_accessible;
// Otherwise, this context class tells us nothing; on to the next.
continue;
}
assert(Target.isInstanceMember());
const CXXRecordDecl *InstanceContext = Target.resolveInstanceContext(S);
if (!InstanceContext) {
OnFailure = AR_dependent;
continue;
}
switch (IsDerivedFromInclusive(InstanceContext, ECRecord)) {
case AR_accessible: return AR_accessible;
case AR_inaccessible: continue;
case AR_dependent: OnFailure = AR_dependent; continue;
}
}
}
// [M3] and [B3] say that, if the target is protected in N, we grant
// access if the access occurs in a friend or member of some class P
// that's a subclass of N and where the target has some natural
// access in P. The 'member' aspect is easy to handle because P
// would necessarily be one of the effective-context records, and we
// address that above. The 'friend' aspect is completely ridiculous
// to implement because there are no restrictions at all on P
// *unless* the [class.protected] restriction applies. If it does,
// however, we should ignore whether the naming class is a friend,
// and instead rely on whether any potential P is a friend.
if (Access == AS_protected && Target.isInstanceMember()) {
// Compute the instance context if possible.
const CXXRecordDecl *InstanceContext = nullptr;
if (Target.hasInstanceContext()) {
InstanceContext = Target.resolveInstanceContext(S);
if (!InstanceContext) return AR_dependent;
}
switch (GetProtectedFriendKind(S, EC, InstanceContext, NamingClass)) {
case AR_accessible: return AR_accessible;
case AR_inaccessible: return OnFailure;
case AR_dependent: return AR_dependent;
}
llvm_unreachable("impossible friendship kind");
}
switch (GetFriendKind(S, EC, NamingClass)) {
case AR_accessible: return AR_accessible;
case AR_inaccessible: return OnFailure;
case AR_dependent: return AR_dependent;
}
// Silence bogus warnings
llvm_unreachable("impossible friendship kind");
}
/// Finds the best path from the naming class to the declaring class,
/// taking friend declarations into account.
///
/// C++0x [class.access.base]p5:
/// A member m is accessible at the point R when named in class N if
/// [M1] m as a member of N is public, or
/// [M2] m as a member of N is private, and R occurs in a member or
/// friend of class N, or
/// [M3] m as a member of N is protected, and R occurs in a member or
/// friend of class N, or in a member or friend of a class P
/// derived from N, where m as a member of P is public, private,
/// or protected, or
/// [M4] there exists a base class B of N that is accessible at R, and
/// m is accessible at R when named in class B.
///
/// C++0x [class.access.base]p4:
/// A base class B of N is accessible at R, if
/// [B1] an invented public member of B would be a public member of N, or
/// [B2] R occurs in a member or friend of class N, and an invented public
/// member of B would be a private or protected member of N, or
/// [B3] R occurs in a member or friend of a class P derived from N, and an
/// invented public member of B would be a private or protected member
/// of P, or
/// [B4] there exists a class S such that B is a base class of S accessible
/// at R and S is a base class of N accessible at R.
///
/// Along a single inheritance path we can restate both of these
/// iteratively:
///
/// First, we note that M1-4 are equivalent to B1-4 if the member is
/// treated as a notional base of its declaring class with inheritance
/// access equivalent to the member's access. Therefore we need only
/// ask whether a class B is accessible from a class N in context R.
///
/// Let B_1 .. B_n be the inheritance path in question (i.e. where
/// B_1 = N, B_n = B, and for all i, B_{i+1} is a direct base class of
/// B_i). For i in 1..n, we will calculate ACAB(i), the access to the
/// closest accessible base in the path:
/// Access(a, b) = (* access on the base specifier from a to b *)
/// Merge(a, forbidden) = forbidden
/// Merge(a, private) = forbidden
/// Merge(a, b) = min(a,b)
/// Accessible(c, forbidden) = false
/// Accessible(c, private) = (R is c) || IsFriend(c, R)
/// Accessible(c, protected) = (R derived from c) || IsFriend(c, R)
/// Accessible(c, public) = true
/// ACAB(n) = public
/// ACAB(i) =
/// let AccessToBase = Merge(Access(B_i, B_{i+1}), ACAB(i+1)) in
/// if Accessible(B_i, AccessToBase) then public else AccessToBase
///
/// B is an accessible base of N at R iff ACAB(1) = public.
///
/// \param FinalAccess the access of the "final step", or AS_public if
/// there is no final step.
/// \return null if friendship is dependent
static CXXBasePath *FindBestPath(Sema &S,
const EffectiveContext &EC,
AccessTarget &Target,
AccessSpecifier FinalAccess,
CXXBasePaths &Paths) {
// Derive the paths to the desired base.
const CXXRecordDecl *Derived = Target.getNamingClass();
const CXXRecordDecl *Base = Target.getDeclaringClass();
// FIXME: fail correctly when there are dependent paths.
bool isDerived = Derived->isDerivedFrom(const_cast<CXXRecordDecl*>(Base),
Paths);
assert(isDerived && "derived class not actually derived from base");
(void) isDerived;
CXXBasePath *BestPath = nullptr;
assert(FinalAccess != AS_none && "forbidden access after declaring class");
bool AnyDependent = false;
// Derive the friend-modified access along each path.
for (CXXBasePaths::paths_iterator PI = Paths.begin(), PE = Paths.end();
PI != PE; ++PI) {
AccessTarget::SavedInstanceContext _ = Target.saveInstanceContext();
// Walk through the path backwards.
AccessSpecifier PathAccess = FinalAccess;
CXXBasePath::iterator I = PI->end(), E = PI->begin();
while (I != E) {
--I;
assert(PathAccess != AS_none);
// If the declaration is a private member of a base class, there
// is no level of friendship in derived classes that can make it
// accessible.
if (PathAccess == AS_private) {
PathAccess = AS_none;
break;
}
const CXXRecordDecl *NC = I->Class->getCanonicalDecl();
AccessSpecifier BaseAccess = I->Base->getAccessSpecifier();
PathAccess = std::max(PathAccess, BaseAccess);
switch (HasAccess(S, EC, NC, PathAccess, Target)) {
case AR_inaccessible: break;
case AR_accessible:
PathAccess = AS_public;
// Future tests are not against members and so do not have
// instance context.
Target.suppressInstanceContext();
break;
case AR_dependent:
AnyDependent = true;
goto Next;
}
}
// Note that we modify the path's Access field to the
// friend-modified access.
if (BestPath == nullptr || PathAccess < BestPath->Access) {
BestPath = &*PI;
BestPath->Access = PathAccess;
// Short-circuit if we found a public path.
if (BestPath->Access == AS_public)
return BestPath;
}
Next: ;
}
assert((!BestPath || BestPath->Access != AS_public) &&
"fell out of loop with public path");
// We didn't find a public path, but at least one path was subject
// to dependent friendship, so delay the check.
if (AnyDependent)
return nullptr;
return BestPath;
}
/// Given that an entity has protected natural access, check whether
/// access might be denied because of the protected member access
/// restriction.
///
/// \return true if a note was emitted
static bool TryDiagnoseProtectedAccess(Sema &S, const EffectiveContext &EC,
AccessTarget &Target) {
// Only applies to instance accesses.
if (!Target.isInstanceMember())
return false;
assert(Target.isMemberAccess());
const CXXRecordDecl *NamingClass = Target.getEffectiveNamingClass();
for (EffectiveContext::record_iterator
I = EC.Records.begin(), E = EC.Records.end(); I != E; ++I) {
const CXXRecordDecl *ECRecord = *I;
switch (IsDerivedFromInclusive(ECRecord, NamingClass)) {
case AR_accessible: break;
case AR_inaccessible: continue;
case AR_dependent: continue;
}
// The effective context is a subclass of the declaring class.
// Check whether the [class.protected] restriction is limiting
// access.
// To get this exactly right, this might need to be checked more
// holistically; it's not necessarily the case that gaining
// access here would grant us access overall.
NamedDecl *D = Target.getTargetDecl();
// If we don't have an instance context, [class.protected] says the
// naming class has to equal the context class.
if (!Target.hasInstanceContext()) {
// If it does, the restriction doesn't apply.
if (NamingClass == ECRecord) continue;
// TODO: it would be great to have a fixit here, since this is
// such an obvious error.
S.Diag(D->getLocation(), diag::note_access_protected_restricted_noobject)
<< S.Context.getTypeDeclType(ECRecord);
return true;
}
const CXXRecordDecl *InstanceContext = Target.resolveInstanceContext(S);
assert(InstanceContext && "diagnosing dependent access");
switch (IsDerivedFromInclusive(InstanceContext, ECRecord)) {
case AR_accessible: continue;
case AR_dependent: continue;
case AR_inaccessible:
break;
}
// Okay, the restriction seems to be what's limiting us.
// Use a special diagnostic for constructors and destructors.
if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D) ||
(isa<FunctionTemplateDecl>(D) &&
isa<CXXConstructorDecl>(
cast<FunctionTemplateDecl>(D)->getTemplatedDecl()))) {
return S.Diag(D->getLocation(),
diag::note_access_protected_restricted_ctordtor)
<< isa<CXXDestructorDecl>(D->getAsFunction());
}
// Otherwise, use the generic diagnostic.
return S.Diag(D->getLocation(),
diag::note_access_protected_restricted_object)
<< S.Context.getTypeDeclType(ECRecord);
}
return false;
}
/// We are unable to access a given declaration due to its direct
/// access control; diagnose that.
static void diagnoseBadDirectAccess(Sema &S,
const EffectiveContext &EC,
AccessTarget &entity) {
assert(entity.isMemberAccess());
NamedDecl *D = entity.getTargetDecl();
if (D->getAccess() == AS_protected &&
TryDiagnoseProtectedAccess(S, EC, entity))
return;
// Find an original declaration.
while (D->isOutOfLine()) {
NamedDecl *PrevDecl = nullptr;
if (VarDecl *VD = dyn_cast<VarDecl>(D))
PrevDecl = VD->getPreviousDecl();
else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
PrevDecl = FD->getPreviousDecl();
else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(D))
PrevDecl = TND->getPreviousDecl();
else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
if (isa<RecordDecl>(D) && cast<RecordDecl>(D)->isInjectedClassName())
break;
PrevDecl = TD->getPreviousDecl();
}
if (!PrevDecl) break;
D = PrevDecl;
}
CXXRecordDecl *DeclaringClass = FindDeclaringClass(D);
Decl *ImmediateChild;
if (D->getDeclContext() == DeclaringClass)
ImmediateChild = D;
else {
DeclContext *DC = D->getDeclContext();
while (DC->getParent() != DeclaringClass)
DC = DC->getParent();
ImmediateChild = cast<Decl>(DC);
}
// Check whether there's an AccessSpecDecl preceding this in the
// chain of the DeclContext.
bool isImplicit = true;
for (const auto *I : DeclaringClass->decls()) {
if (I == ImmediateChild) break;
if (isa<AccessSpecDecl>(I)) {
isImplicit = false;
break;
}
}
S.Diag(D->getLocation(), diag::note_access_natural)
<< (unsigned) (D->getAccess() == AS_protected)
<< isImplicit;
}
/// Diagnose the path which caused the given declaration or base class
/// to become inaccessible.
static void DiagnoseAccessPath(Sema &S,
const EffectiveContext &EC,
AccessTarget &entity) {
// Save the instance context to preserve invariants.
AccessTarget::SavedInstanceContext _ = entity.saveInstanceContext();
// This basically repeats the main algorithm but keeps some more
// information.
// The natural access so far.
AccessSpecifier accessSoFar = AS_public;
// Check whether we have special rights to the declaring class.
if (entity.isMemberAccess()) {
NamedDecl *D = entity.getTargetDecl();
accessSoFar = D->getAccess();
const CXXRecordDecl *declaringClass = entity.getDeclaringClass();
switch (HasAccess(S, EC, declaringClass, accessSoFar, entity)) {
// If the declaration is accessible when named in its declaring
// class, then we must be constrained by the path.
case AR_accessible:
accessSoFar = AS_public;
entity.suppressInstanceContext();
break;
case AR_inaccessible:
if (accessSoFar == AS_private ||
declaringClass == entity.getEffectiveNamingClass())
return diagnoseBadDirectAccess(S, EC, entity);
break;
case AR_dependent:
llvm_unreachable("cannot diagnose dependent access");
}
}
CXXBasePaths paths;
CXXBasePath &path = *FindBestPath(S, EC, entity, accessSoFar, paths);
assert(path.Access != AS_public);
CXXBasePath::iterator i = path.end(), e = path.begin();
CXXBasePath::iterator constrainingBase = i;
while (i != e) {
--i;
assert(accessSoFar != AS_none && accessSoFar != AS_private);
// Is the entity accessible when named in the deriving class, as
// modified by the base specifier?
const CXXRecordDecl *derivingClass = i->Class->getCanonicalDecl();
const CXXBaseSpecifier *base = i->Base;
// If the access to this base is worse than the access we have to
// the declaration, remember it.
AccessSpecifier baseAccess = base->getAccessSpecifier();
if (baseAccess > accessSoFar) {
constrainingBase = i;
accessSoFar = baseAccess;
}
switch (HasAccess(S, EC, derivingClass, accessSoFar, entity)) {
case AR_inaccessible: break;
case AR_accessible:
accessSoFar = AS_public;
entity.suppressInstanceContext();
constrainingBase = nullptr;
break;
case AR_dependent:
llvm_unreachable("cannot diagnose dependent access");
}
// If this was private inheritance, but we don't have access to
// the deriving class, we're done.
if (accessSoFar == AS_private) {
assert(baseAccess == AS_private);
assert(constrainingBase == i);
break;
}
}
// If we don't have a constraining base, the access failure must be
// due to the original declaration.
if (constrainingBase == path.end())
return diagnoseBadDirectAccess(S, EC, entity);
// We're constrained by inheritance, but we want to say
// "declared private here" if we're diagnosing a hierarchy
// conversion and this is the final step.
unsigned diagnostic;
if (entity.isMemberAccess() ||
constrainingBase + 1 != path.end()) {
diagnostic = diag::note_access_constrained_by_path;
} else {
diagnostic = diag::note_access_natural;
}
const CXXBaseSpecifier *base = constrainingBase->Base;
S.Diag(base->getSourceRange().getBegin(), diagnostic)
<< base->getSourceRange()
<< (base->getAccessSpecifier() == AS_protected)
<< (base->getAccessSpecifierAsWritten() == AS_none);
if (entity.isMemberAccess())
S.Diag(entity.getTargetDecl()->getLocation(),
diag::note_member_declared_at);
}
static void DiagnoseBadAccess(Sema &S, SourceLocation Loc,
const EffectiveContext &EC,
AccessTarget &Entity) {
const CXXRecordDecl *NamingClass = Entity.getNamingClass();
const CXXRecordDecl *DeclaringClass = Entity.getDeclaringClass();
NamedDecl *D = (Entity.isMemberAccess() ? Entity.getTargetDecl() : nullptr);
S.Diag(Loc, Entity.getDiag())
<< (Entity.getAccess() == AS_protected)
<< (D ? D->getDeclName() : DeclarationName())
<< S.Context.getTypeDeclType(NamingClass)
<< S.Context.getTypeDeclType(DeclaringClass);
DiagnoseAccessPath(S, EC, Entity);
}
/// MSVC has a bug where if during an using declaration name lookup,
/// the declaration found is unaccessible (private) and that declaration
/// was bring into scope via another using declaration whose target
/// declaration is accessible (public) then no error is generated.
/// Example:
/// class A {
/// public:
/// int f();
/// };
/// class B : public A {
/// private:
/// using A::f;
/// };
/// class C : public B {
/// private:
/// using B::f;
/// };
///
/// Here, B::f is private so this should fail in Standard C++, but
/// because B::f refers to A::f which is public MSVC accepts it.
static bool IsMicrosoftUsingDeclarationAccessBug(Sema& S,
SourceLocation AccessLoc,
AccessTarget &Entity) {
if (UsingShadowDecl *Shadow =
dyn_cast<UsingShadowDecl>(Entity.getTargetDecl())) {
const NamedDecl *OrigDecl = Entity.getTargetDecl()->getUnderlyingDecl();
if (Entity.getTargetDecl()->getAccess() == AS_private &&
(OrigDecl->getAccess() == AS_public ||
OrigDecl->getAccess() == AS_protected)) {
S.Diag(AccessLoc, diag::ext_ms_using_declaration_inaccessible)
<< Shadow->getUsingDecl()->getQualifiedNameAsString()
<< OrigDecl->getQualifiedNameAsString();
return true;
}
}
return false;
}
/// Determines whether the accessed entity is accessible. Public members
/// have been weeded out by this point.
static AccessResult IsAccessible(Sema &S,
const EffectiveContext &EC,
AccessTarget &Entity) {
// Determine the actual naming class.
const CXXRecordDecl *NamingClass = Entity.getEffectiveNamingClass();
AccessSpecifier UnprivilegedAccess = Entity.getAccess();
assert(UnprivilegedAccess != AS_public && "public access not weeded out");
// Before we try to recalculate access paths, try to white-list
// accesses which just trade in on the final step, i.e. accesses
// which don't require [M4] or [B4]. These are by far the most
// common forms of privileged access.
if (UnprivilegedAccess != AS_none) {
switch (HasAccess(S, EC, NamingClass, UnprivilegedAccess, Entity)) {
case AR_dependent:
// This is actually an interesting policy decision. We don't
// *have* to delay immediately here: we can do the full access
// calculation in the hope that friendship on some intermediate
// class will make the declaration accessible non-dependently.
// But that's not cheap, and odds are very good (note: assertion
// made without data) that the friend declaration will determine
// access.
return AR_dependent;
case AR_accessible: return AR_accessible;
case AR_inaccessible: break;
}
}
AccessTarget::SavedInstanceContext _ = Entity.saveInstanceContext();
// We lower member accesses to base accesses by pretending that the
// member is a base class of its declaring class.
AccessSpecifier FinalAccess;
if (Entity.isMemberAccess()) {
// Determine if the declaration is accessible from EC when named
// in its declaring class.
NamedDecl *Target = Entity.getTargetDecl();
const CXXRecordDecl *DeclaringClass = Entity.getDeclaringClass();
FinalAccess = Target->getAccess();
switch (HasAccess(S, EC, DeclaringClass, FinalAccess, Entity)) {
case AR_accessible:
// Target is accessible at EC when named in its declaring class.
// We can now hill-climb and simply check whether the declaring
// class is accessible as a base of the naming class. This is
// equivalent to checking the access of a notional public
// member with no instance context.
FinalAccess = AS_public;
Entity.suppressInstanceContext();
break;
case AR_inaccessible: break;
case AR_dependent: return AR_dependent; // see above
}
if (DeclaringClass == NamingClass)
return (FinalAccess == AS_public ? AR_accessible : AR_inaccessible);
} else {
FinalAccess = AS_public;
}
assert(Entity.getDeclaringClass() != NamingClass);
// Append the declaration's access if applicable.
CXXBasePaths Paths;
CXXBasePath *Path = FindBestPath(S, EC, Entity, FinalAccess, Paths);
if (!Path)
return AR_dependent;
assert(Path->Access <= UnprivilegedAccess &&
"access along best path worse than direct?");
if (Path->Access == AS_public)
return AR_accessible;
return AR_inaccessible;
}
static void DelayDependentAccess(Sema &S,
const EffectiveContext &EC,
SourceLocation Loc,
const AccessTarget &Entity) {
assert(EC.isDependent() && "delaying non-dependent access");
DeclContext *DC = EC.getInnerContext();
assert(DC->isDependentContext() && "delaying non-dependent access");
DependentDiagnostic::Create(S.Context, DC, DependentDiagnostic::Access,
Loc,
Entity.isMemberAccess(),
Entity.getAccess(),
Entity.getTargetDecl(),
Entity.getNamingClass(),
Entity.getBaseObjectType(),
Entity.getDiag());
}
/// Checks access to an entity from the given effective context.
static AccessResult CheckEffectiveAccess(Sema &S,
const EffectiveContext &EC,
SourceLocation Loc,
AccessTarget &Entity) {
assert(Entity.getAccess() != AS_public && "called for public access!");
switch (IsAccessible(S, EC, Entity)) {
case AR_dependent:
DelayDependentAccess(S, EC, Loc, Entity);
return AR_dependent;
case AR_inaccessible:
if (S.getLangOpts().MSVCCompat &&
IsMicrosoftUsingDeclarationAccessBug(S, Loc, Entity))
return AR_accessible;
if (!Entity.isQuiet())
DiagnoseBadAccess(S, Loc, EC, Entity);
return AR_inaccessible;
case AR_accessible:
return AR_accessible;
}
// silence unnecessary warning
llvm_unreachable("invalid access result");
}
static Sema::AccessResult CheckAccess(Sema &S, SourceLocation Loc,
AccessTarget &Entity) {
// If the access path is public, it's accessible everywhere.
if (Entity.getAccess() == AS_public)
return Sema::AR_accessible;
// If we're currently parsing a declaration, we may need to delay
// access control checking, because our effective context might be
// different based on what the declaration comes out as.
//
// For example, we might be parsing a declaration with a scope
// specifier, like this:
// A::private_type A::foo() { ... }
//
// Or we might be parsing something that will turn out to be a friend:
// void foo(A::private_type);
// void B::foo(A::private_type);
if (S.DelayedDiagnostics.shouldDelayDiagnostics()) {
S.DelayedDiagnostics.add(DelayedDiagnostic::makeAccess(Loc, Entity));
return Sema::AR_delayed;
}
EffectiveContext EC(S.CurContext);
switch (CheckEffectiveAccess(S, EC, Loc, Entity)) {
case AR_accessible: return Sema::AR_accessible;
case AR_inaccessible: return Sema::AR_inaccessible;
case AR_dependent: return Sema::AR_dependent;
}
llvm_unreachable("falling off end");
}
void Sema::HandleDelayedAccessCheck(DelayedDiagnostic &DD, Decl *D) {
// Access control for names used in the declarations of functions
// and function templates should normally be evaluated in the context
// of the declaration, just in case it's a friend of something.
// However, this does not apply to local extern declarations.
DeclContext *DC = D->getDeclContext();
if (D->isLocalExternDecl()) {
DC = D->getLexicalDeclContext();
} else if (FunctionDecl *FN = dyn_cast<FunctionDecl>(D)) {
DC = FN;
} else if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) {
DC = cast<DeclContext>(TD->getTemplatedDecl());
}
EffectiveContext EC(DC);
AccessTarget Target(DD.getAccessData());
if (CheckEffectiveAccess(*this, EC, DD.Loc, Target) == ::AR_inaccessible)
DD.Triggered = true;
}
void Sema::HandleDependentAccessCheck(const DependentDiagnostic &DD,
const MultiLevelTemplateArgumentList &TemplateArgs) {
SourceLocation Loc = DD.getAccessLoc();
AccessSpecifier Access = DD.getAccess();
Decl *NamingD = FindInstantiatedDecl(Loc, DD.getAccessNamingClass(),
TemplateArgs);
if (!NamingD) return;
Decl *TargetD = FindInstantiatedDecl(Loc, DD.getAccessTarget(),
TemplateArgs);
if (!TargetD) return;
if (DD.isAccessToMember()) {
CXXRecordDecl *NamingClass = cast<CXXRecordDecl>(NamingD);
NamedDecl *TargetDecl = cast<NamedDecl>(TargetD);
QualType BaseObjectType = DD.getAccessBaseObjectType();
if (!BaseObjectType.isNull()) {
BaseObjectType = SubstType(BaseObjectType, TemplateArgs, Loc,
DeclarationName());
if (BaseObjectType.isNull()) return;
}
AccessTarget Entity(Context,
AccessTarget::Member,
NamingClass,
DeclAccessPair::make(TargetDecl, Access),
BaseObjectType);
Entity.setDiag(DD.getDiagnostic());
CheckAccess(*this, Loc, Entity);
} else {
AccessTarget Entity(Context,
AccessTarget::Base,
cast<CXXRecordDecl>(TargetD),
cast<CXXRecordDecl>(NamingD),
Access);
Entity.setDiag(DD.getDiagnostic());
CheckAccess(*this, Loc, Entity);
}
}
Sema::AccessResult Sema::CheckUnresolvedLookupAccess(UnresolvedLookupExpr *E,
DeclAccessPair Found) {
if (!getLangOpts().AccessControl ||
!E->getNamingClass() ||
Found.getAccess() == AS_public)
return AR_accessible;
AccessTarget Entity(Context, AccessTarget::Member, E->getNamingClass(),
Found, QualType());
Entity.setDiag(diag::err_access) << E->getSourceRange();
return CheckAccess(*this, E->getNameLoc(), Entity);
}
/// Perform access-control checking on a previously-unresolved member
/// access which has now been resolved to a member.
Sema::AccessResult Sema::CheckUnresolvedMemberAccess(UnresolvedMemberExpr *E,
DeclAccessPair Found) {
if (!getLangOpts().AccessControl ||
Found.getAccess() == AS_public)
return AR_accessible;
QualType BaseType = E->getBaseType();
if (E->isArrow())
BaseType = BaseType->getAs<PointerType>()->getPointeeType();
AccessTarget Entity(Context, AccessTarget::Member, E->getNamingClass(),
Found, BaseType);
Entity.setDiag(diag::err_access) << E->getSourceRange();
return CheckAccess(*this, E->getMemberLoc(), Entity);
}
/// Is the given special member function accessible for the purposes of
/// deciding whether to define a special member function as deleted?
bool Sema::isSpecialMemberAccessibleForDeletion(CXXMethodDecl *decl,
AccessSpecifier access,
QualType objectType) {
// Fast path.
if (access == AS_public || !getLangOpts().AccessControl) return true;
AccessTarget entity(Context, AccessTarget::Member, decl->getParent(),
DeclAccessPair::make(decl, access), objectType);
// Suppress diagnostics.
entity.setDiag(PDiag());
switch (CheckAccess(*this, SourceLocation(), entity)) {
case AR_accessible: return true;
case AR_inaccessible: return false;
case AR_dependent: llvm_unreachable("dependent for =delete computation");
case AR_delayed: llvm_unreachable("cannot delay =delete computation");
}
llvm_unreachable("bad access result");
}
Sema::AccessResult Sema::CheckDestructorAccess(SourceLocation Loc,
CXXDestructorDecl *Dtor,
const PartialDiagnostic &PDiag,
QualType ObjectTy) {
if (!getLangOpts().AccessControl)
return AR_accessible;
// There's never a path involved when checking implicit destructor access.
AccessSpecifier Access = Dtor->getAccess();
if (Access == AS_public)
return AR_accessible;
CXXRecordDecl *NamingClass = Dtor->getParent();
if (ObjectTy.isNull()) ObjectTy = Context.getTypeDeclType(NamingClass);
AccessTarget Entity(Context, AccessTarget::Member, NamingClass,
DeclAccessPair::make(Dtor, Access),
ObjectTy);
Entity.setDiag(PDiag); // TODO: avoid copy
return CheckAccess(*this, Loc, Entity);
}
/// Checks access to a constructor.
Sema::AccessResult Sema::CheckConstructorAccess(SourceLocation UseLoc,
CXXConstructorDecl *Constructor,
const InitializedEntity &Entity,
AccessSpecifier Access,
bool IsCopyBindingRefToTemp) {
if (!getLangOpts().AccessControl || Access == AS_public)
return AR_accessible;
PartialDiagnostic PD(PDiag());
switch (Entity.getKind()) {
default:
PD = PDiag(IsCopyBindingRefToTemp
? diag::ext_rvalue_to_reference_access_ctor
: diag::err_access_ctor);
break;
case InitializedEntity::EK_Base:
PD = PDiag(diag::err_access_base_ctor);
PD << Entity.isInheritedVirtualBase()
<< Entity.getBaseSpecifier()->getType() << getSpecialMember(Constructor);
break;
case InitializedEntity::EK_Member: {
const FieldDecl *Field = cast<FieldDecl>(Entity.getDecl());
PD = PDiag(diag::err_access_field_ctor);
PD << Field->getType() << getSpecialMember(Constructor);
break;
}
case InitializedEntity::EK_LambdaCapture: {
StringRef VarName = Entity.getCapturedVarName();
PD = PDiag(diag::err_access_lambda_capture);
PD << VarName << Entity.getType() << getSpecialMember(Constructor);
break;
}
}
return CheckConstructorAccess(UseLoc, Constructor, Entity, Access, PD);
}
/// Checks access to a constructor.
Sema::AccessResult Sema::CheckConstructorAccess(SourceLocation UseLoc,
CXXConstructorDecl *Constructor,
const InitializedEntity &Entity,
AccessSpecifier Access,
const PartialDiagnostic &PD) {
if (!getLangOpts().AccessControl ||
Access == AS_public)
return AR_accessible;
CXXRecordDecl *NamingClass = Constructor->getParent();
// Initializing a base sub-object is an instance method call on an
// object of the derived class. Otherwise, we have an instance method
// call on an object of the constructed type.
CXXRecordDecl *ObjectClass;
if (Entity.getKind() == InitializedEntity::EK_Base) {
ObjectClass = cast<CXXConstructorDecl>(CurContext)->getParent();
} else {
ObjectClass = NamingClass;
}
AccessTarget AccessEntity(Context, AccessTarget::Member, NamingClass,
DeclAccessPair::make(Constructor, Access),
Context.getTypeDeclType(ObjectClass));
AccessEntity.setDiag(PD);
return CheckAccess(*this, UseLoc, AccessEntity);
}
/// Checks access to an overloaded operator new or delete.
Sema::AccessResult Sema::CheckAllocationAccess(SourceLocation OpLoc,
SourceRange PlacementRange,
CXXRecordDecl *NamingClass,
DeclAccessPair Found,
bool Diagnose) {
if (!getLangOpts().AccessControl ||
!NamingClass ||
Found.getAccess() == AS_public)
return AR_accessible;
AccessTarget Entity(Context, AccessTarget::Member, NamingClass, Found,
QualType());
if (Diagnose)
Entity.setDiag(diag::err_access)
<< PlacementRange;
return CheckAccess(*this, OpLoc, Entity);
}
/// \brief Checks access to a member.
Sema::AccessResult Sema::CheckMemberAccess(SourceLocation UseLoc,
CXXRecordDecl *NamingClass,
DeclAccessPair Found) {
if (!getLangOpts().AccessControl ||
!NamingClass ||
Found.getAccess() == AS_public)
return AR_accessible;
AccessTarget Entity(Context, AccessTarget::Member, NamingClass,
Found, QualType());
return CheckAccess(*this, UseLoc, Entity);
}
/// Checks access to an overloaded member operator, including
/// conversion operators.
Sema::AccessResult Sema::CheckMemberOperatorAccess(SourceLocation OpLoc,
Expr *ObjectExpr,
Expr *ArgExpr,
DeclAccessPair Found) {
if (!getLangOpts().AccessControl ||
Found.getAccess() == AS_public)
return AR_accessible;
const RecordType *RT = ObjectExpr->getType()->castAs<RecordType>();
CXXRecordDecl *NamingClass = cast<CXXRecordDecl>(RT->getDecl());
AccessTarget Entity(Context, AccessTarget::Member, NamingClass, Found,
ObjectExpr->getType());
Entity.setDiag(diag::err_access)
<< ObjectExpr->getSourceRange()
<< (ArgExpr ? ArgExpr->getSourceRange() : SourceRange());
return CheckAccess(*this, OpLoc, Entity);
}
/// Checks access to the target of a friend declaration.
Sema::AccessResult Sema::CheckFriendAccess(NamedDecl *target) {
assert(isa<CXXMethodDecl>(target->getAsFunction()));
// Friendship lookup is a redeclaration lookup, so there's never an
// inheritance path modifying access.
AccessSpecifier access = target->getAccess();
if (!getLangOpts().AccessControl || access == AS_public)
return AR_accessible;
CXXMethodDecl *method = cast<CXXMethodDecl>(target->getAsFunction());
assert(method->getQualifier());
AccessTarget entity(Context, AccessTarget::Member,
cast<CXXRecordDecl>(target->getDeclContext()),
DeclAccessPair::make(target, access),
/*no instance context*/ QualType());
entity.setDiag(diag::err_access_friend_function)
<< method->getQualifierLoc().getSourceRange();
// We need to bypass delayed-diagnostics because we might be called
// while the ParsingDeclarator is active.
EffectiveContext EC(CurContext);
switch (CheckEffectiveAccess(*this, EC, target->getLocation(), entity)) {
case AR_accessible: return Sema::AR_accessible;
case AR_inaccessible: return Sema::AR_inaccessible;
case AR_dependent: return Sema::AR_dependent;
}
llvm_unreachable("falling off end");
}
Sema::AccessResult Sema::CheckAddressOfMemberAccess(Expr *OvlExpr,
DeclAccessPair Found) {
if (!getLangOpts().AccessControl ||
Found.getAccess() == AS_none ||
Found.getAccess() == AS_public)
return AR_accessible;
OverloadExpr *Ovl = OverloadExpr::find(OvlExpr).Expression;
CXXRecordDecl *NamingClass = Ovl->getNamingClass();
AccessTarget Entity(Context, AccessTarget::Member, NamingClass, Found,
/*no instance context*/ QualType());
Entity.setDiag(diag::err_access)
<< Ovl->getSourceRange();
return CheckAccess(*this, Ovl->getNameLoc(), Entity);
}
/// Checks access for a hierarchy conversion.
///
/// \param ForceCheck true if this check should be performed even if access
/// control is disabled; some things rely on this for semantics
/// \param ForceUnprivileged true if this check should proceed as if the
/// context had no special privileges
Sema::AccessResult Sema::CheckBaseClassAccess(SourceLocation AccessLoc,
QualType Base,
QualType Derived,
const CXXBasePath &Path,
unsigned DiagID,
bool ForceCheck,
bool ForceUnprivileged) {
if (!ForceCheck && !getLangOpts().AccessControl)
return AR_accessible;
if (Path.Access == AS_public)
return AR_accessible;
CXXRecordDecl *BaseD, *DerivedD;
BaseD = cast<CXXRecordDecl>(Base->getAs<RecordType>()->getDecl());
DerivedD = cast<CXXRecordDecl>(Derived->getAs<RecordType>()->getDecl());
AccessTarget Entity(Context, AccessTarget::Base, BaseD, DerivedD,
Path.Access);
if (DiagID)
Entity.setDiag(DiagID) << Derived << Base;
if (ForceUnprivileged) {
switch (CheckEffectiveAccess(*this, EffectiveContext(),
AccessLoc, Entity)) {
case ::AR_accessible: return Sema::AR_accessible;
case ::AR_inaccessible: return Sema::AR_inaccessible;
case ::AR_dependent: return Sema::AR_dependent;
}
llvm_unreachable("unexpected result from CheckEffectiveAccess");
}
return CheckAccess(*this, AccessLoc, Entity);
}
/// Checks access to all the declarations in the given result set.
void Sema::CheckLookupAccess(const LookupResult &R) {
assert(getLangOpts().AccessControl
&& "performing access check without access control");
assert(R.getNamingClass() && "performing access check without naming class");
for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
if (I.getAccess() != AS_public) {
AccessTarget Entity(Context, AccessedEntity::Member,
R.getNamingClass(), I.getPair(),
R.getBaseObjectType());
Entity.setDiag(diag::err_access);
CheckAccess(*this, R.getNameLoc(), Entity);
}
}
}
/// Checks access to Decl from the given class. The check will take access
/// specifiers into account, but no member access expressions and such.
///
/// \param Decl the declaration to check if it can be accessed
/// \param Ctx the class/context from which to start the search
/// \return true if the Decl is accessible from the Class, false otherwise.
bool Sema::IsSimplyAccessible(NamedDecl *Decl, DeclContext *Ctx) {
if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx)) {
if (!Decl->isCXXClassMember())
return true;
QualType qType = Class->getTypeForDecl()->getCanonicalTypeInternal();
AccessTarget Entity(Context, AccessedEntity::Member, Class,
DeclAccessPair::make(Decl, Decl->getAccess()),
qType);
if (Entity.getAccess() == AS_public)
return true;
EffectiveContext EC(CurContext);
return ::IsAccessible(*this, EC, Entity) != ::AR_inaccessible;
}
if (ObjCIvarDecl *Ivar = dyn_cast<ObjCIvarDecl>(Decl)) {
// @public and @package ivars are always accessible.
if (Ivar->getCanonicalAccessControl() == ObjCIvarDecl::Public ||
Ivar->getCanonicalAccessControl() == ObjCIvarDecl::Package)
return true;
// If we are inside a class or category implementation, determine the
// interface we're in.
ObjCInterfaceDecl *ClassOfMethodDecl = nullptr;
if (ObjCMethodDecl *MD = getCurMethodDecl())
ClassOfMethodDecl = MD->getClassInterface();
else if (FunctionDecl *FD = getCurFunctionDecl()) {
if (ObjCImplDecl *Impl
= dyn_cast<ObjCImplDecl>(FD->getLexicalDeclContext())) {
if (ObjCImplementationDecl *IMPD
= dyn_cast<ObjCImplementationDecl>(Impl))
ClassOfMethodDecl = IMPD->getClassInterface();
else if (ObjCCategoryImplDecl* CatImplClass
= dyn_cast<ObjCCategoryImplDecl>(Impl))
ClassOfMethodDecl = CatImplClass->getClassInterface();
}
}
// If we're not in an interface, this ivar is inaccessible.
if (!ClassOfMethodDecl)
return false;
// If we're inside the same interface that owns the ivar, we're fine.
if (declaresSameEntity(ClassOfMethodDecl, Ivar->getContainingInterface()))
return true;
// If the ivar is private, it's inaccessible.
if (Ivar->getCanonicalAccessControl() == ObjCIvarDecl::Private)
return false;
return Ivar->getContainingInterface()->isSuperClassOf(ClassOfMethodDecl);
}
return true;
}
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