/// 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.
CXXRecordDecl *NamingClass = Entity.getNamingClass();
while (NamingClass->isAnonymousStructOrUnion())
NamingClass = cast<CXXRecordDecl>(NamingClass->getParent());
NamingClass = NamingClass->getCanonicalDecl();
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:
FinalAccess = AS_public;
break;
case AR_inaccessible: break;
case AR_dependent: return AR_dependent; // see above
}
if (DeclaringClass == NamingClass)
return (FinalAccess == AS_public ? AR_accessible : AR_inaccessible);
Entity.suppressInstanceContext();
} 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;
}
/// Diagnose the path which caused the given declaration or base class
/// to become inaccessible.
static void DiagnoseAccessPath(Sema &S,
const EffectiveContext &EC,
AccessTarget &Entity) {
AccessSpecifier Access = Entity.getAccess();
const CXXRecordDecl *NamingClass = Entity.getNamingClass();
NamingClass = NamingClass->getCanonicalDecl();
NamedDecl *D = (Entity.isMemberAccess() ? Entity.getTargetDecl() : 0);
const CXXRecordDecl *DeclaringClass = Entity.getDeclaringClass();
// Easy case: the decl's natural access determined its path access.
// We have to check against AS_private here in case Access is AS_none,
// indicating a non-public member of a private base class.
if (D && (Access == D->getAccess() || D->getAccess() == AS_private)) {
switch (HasAccess(S, EC, DeclaringClass, D->getAccess(), Entity)) {
case AR_inaccessible: {
S.Diag(D->getLocation(), diag::note_access_natural)
<< (unsigned) (Access == AS_protected)
<< /*FIXME: not implicitly*/ 0;
return;
}
case AR_accessible: break;
case AR_dependent:
llvm_unreachable("can't diagnose dependent access failures");
return;
}
}
CXXBasePaths Paths;
CXXBasePath &Path = *FindBestPath(S, EC, Entity, AS_public, Paths);
CXXBasePath::iterator I = Path.end(), E = Path.begin();
while (I != E) {
--I;
const CXXBaseSpecifier *BS = I->Base;
AccessSpecifier BaseAccess = BS->getAccessSpecifier();
// If this is public inheritance, or the derived class is a friend,
// skip this step.
if (BaseAccess == AS_public)
continue;
switch (GetFriendKind(S, EC, I->Class)) {
case AR_accessible: continue;
case AR_inaccessible: break;
case AR_dependent:
llvm_unreachable("can't diagnose dependent access failures");
}
// Check whether this base specifier is the tighest point
// constraining access. We have to check against AS_private for
// the same reasons as above.
if (BaseAccess == AS_private || BaseAccess >= Access) {
// 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 (D) diagnostic = diag::note_access_constrained_by_path;
else if (I + 1 == Path.end()) diagnostic = diag::note_access_natural;
else diagnostic = diag::note_access_constrained_by_path;
S.Diag(BS->getSourceRange().getBegin(), diagnostic)
<< BS->getSourceRange()
<< (BaseAccess == AS_protected)
<< (BS->getAccessSpecifierAsWritten() == AS_none);
return;
}
}
llvm_unreachable("access not apparently constrained by path");
}
