/// Collect the visible conversions of a base class.
///
/// \param Base a base class of the class we're considering
/// \param InVirtual whether this base class is a virtual base (or a base
/// of a virtual base)
/// \param Access the access along the inheritance path to this base
/// \param ParentHiddenTypes the conversions provided by the inheritors
/// of this base
/// \param Output the set to which to add conversions from non-virtual bases
/// \param VOutput the set to which to add conversions from virtual bases
/// \param HiddenVBaseCs the set of conversions which were hidden in a
/// virtual base along some inheritance path
static void CollectVisibleConversions(ASTContext &Context,
CXXRecordDecl *Record,
bool InVirtual,
AccessSpecifier Access,
const llvm::SmallPtrSet<CanQualType, 8> &ParentHiddenTypes,
UnresolvedSetImpl &Output,
UnresolvedSetImpl &VOutput,
llvm::SmallPtrSet<NamedDecl*, 8> &HiddenVBaseCs) {
// The set of types which have conversions in this class or its
// subclasses. As an optimization, we don't copy the derived set
// unless it might change.
const llvm::SmallPtrSet<CanQualType, 8> *HiddenTypes = &ParentHiddenTypes;
llvm::SmallPtrSet<CanQualType, 8> HiddenTypesBuffer;
// Collect the direct conversions and figure out which conversions
// will be hidden in the subclasses.
UnresolvedSetImpl &Cs = *Record->getConversionFunctions();
if (!Cs.empty()) {
HiddenTypesBuffer = ParentHiddenTypes;
HiddenTypes = &HiddenTypesBuffer;
for (UnresolvedSetIterator I = Cs.begin(), E = Cs.end(); I != E; ++I) {
bool Hidden =
!HiddenTypesBuffer.insert(GetConversionType(Context, I.getDecl()));
// If this conversion is hidden and we're in a virtual base,
// remember that it's hidden along some inheritance path.
if (Hidden && InVirtual)
HiddenVBaseCs.insert(cast<NamedDecl>(I.getDecl()->getCanonicalDecl()));
// If this conversion isn't hidden, add it to the appropriate output.
else if (!Hidden) {
AccessSpecifier IAccess
= CXXRecordDecl::MergeAccess(Access, I.getAccess());
if (InVirtual)
VOutput.addDecl(I.getDecl(), IAccess);
else
Output.addDecl(I.getDecl(), IAccess);
}
}
}
// Collect information recursively from any base classes.
for (CXXRecordDecl::base_class_iterator
I = Record->bases_begin(), E = Record->bases_end(); I != E; ++I) {
const RecordType *RT = I->getType()->getAs<RecordType>();
if (!RT) continue;
AccessSpecifier BaseAccess
= CXXRecordDecl::MergeAccess(Access, I->getAccessSpecifier());
bool BaseInVirtual = InVirtual || I->isVirtual();
CXXRecordDecl *Base = cast<CXXRecordDecl>(RT->getDecl());
CollectVisibleConversions(Context, Base, BaseInVirtual, BaseAccess,
*HiddenTypes, Output, VOutput, HiddenVBaseCs);
}
}
/// \brief Figure out if an expression could be turned into a call.
///
/// Use this when trying to recover from an error where the programmer may have
/// written just the name of a function instead of actually calling it.
///
/// \param E - The expression to examine.
/// \param ZeroArgCallReturnTy - If the expression can be turned into a call
/// with no arguments, this parameter is set to the type returned by such a
/// call; otherwise, it is set to an empty QualType.
/// \param NonTemplateOverloads - If the expression is an overloaded function
/// name, this parameter is populated with the decls of the various overloads.
bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy,
UnresolvedSetImpl &NonTemplateOverloads) {
ZeroArgCallReturnTy = QualType();
NonTemplateOverloads.clear();
if (const OverloadExpr *Overloads = dyn_cast<OverloadExpr>(&E)) {
for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
// Our overload set may include TemplateDecls, which we'll ignore for our
// present purpose.
if (const FunctionDecl *OverloadDecl = dyn_cast<FunctionDecl>(*it)) {
NonTemplateOverloads.addDecl(*it);
if (OverloadDecl->getMinRequiredArguments() == 0)
ZeroArgCallReturnTy = OverloadDecl->getResultType();
}
}
return true;
}
if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(&E)) {
if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
if (Fun->getMinRequiredArguments() == 0)
ZeroArgCallReturnTy = Fun->getResultType();
return true;
}
}
// We don't have an expression that's convenient to get a FunctionDecl from,
// but we can at least check if the type is "function of 0 arguments".
QualType ExprTy = E.getType();
const FunctionType *FunTy = NULL;
QualType PointeeTy = ExprTy->getPointeeType();
if (!PointeeTy.isNull())
FunTy = PointeeTy->getAs<FunctionType>();
if (!FunTy)
FunTy = ExprTy->getAs<FunctionType>();
if (!FunTy && ExprTy == Context.BoundMemberTy) {
// Look for the bound-member type. If it's still overloaded, give up,
// although we probably should have fallen into the OverloadExpr case above
// if we actually have an overloaded bound member.
QualType BoundMemberTy = Expr::findBoundMemberType(&E);
if (!BoundMemberTy.isNull())
FunTy = BoundMemberTy->castAs<FunctionType>();
}
if (const FunctionProtoType *FPT =
dyn_cast_or_null<FunctionProtoType>(FunTy)) {
if (FPT->getNumArgs() == 0)
ZeroArgCallReturnTy = FunTy->getResultType();
return true;
}
return false;
}
static void notePlausibleOverloads(Sema &S, SourceLocation Loc,
const UnresolvedSetImpl &Overloads,
bool (*IsPlausibleResult)(QualType)) {
if (!IsPlausibleResult)
return noteOverloads(S, Overloads, Loc);
UnresolvedSet<2> PlausibleOverloads;
for (OverloadExpr::decls_iterator It = Overloads.begin(),
DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
const FunctionDecl *OverloadDecl = cast<FunctionDecl>(*It);
QualType OverloadResultTy = OverloadDecl->getResultType();
if (IsPlausibleResult(OverloadResultTy))
PlausibleOverloads.addDecl(It.getDecl());
}
noteOverloads(S, PlausibleOverloads, Loc);
}
/// \brief Give notes for a set of overloads.
///
/// A companion to isExprCallable. In cases when the name that the programmer
/// wrote was an overloaded function, we may be able to make some guesses about
/// plausible overloads based on their return types; such guesses can be handed
/// off to this method to be emitted as notes.
///
/// \param Overloads - The overloads to note.
/// \param FinalNoteLoc - If we've suppressed printing some overloads due to
/// -fshow-overloads=best, this is the location to attach to the note about too
/// many candidates. Typically this will be the location of the original
/// ill-formed expression.
void Sema::NoteOverloads(const UnresolvedSetImpl &Overloads,
const SourceLocation FinalNoteLoc) {
int ShownOverloads = 0;
int SuppressedOverloads = 0;
for (UnresolvedSetImpl::iterator It = Overloads.begin(),
DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
// FIXME: Magic number for max shown overloads stolen from
// OverloadCandidateSet::NoteCandidates.
if (ShownOverloads >= 4 &&
Diags.getShowOverloads() == DiagnosticsEngine::Ovl_Best) {
++SuppressedOverloads;
continue;
}
Diag(cast<FunctionDecl>(*It)->getSourceRange().getBegin(),
diag::note_member_ref_possible_intended_overload);
++ShownOverloads;
}
if (SuppressedOverloads)
Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates)
<< SuppressedOverloads;
}
/// Collect the visible conversions of a class.
///
/// This would be extremely straightforward if it weren't for virtual
/// bases. It might be worth special-casing that, really.
static void CollectVisibleConversions(ASTContext &Context,
CXXRecordDecl *Record,
UnresolvedSetImpl &Output) {
// The collection of all conversions in virtual bases that we've
// found. These will be added to the output as long as they don't
// appear in the hidden-conversions set.
UnresolvedSet<8> VBaseCs;
// The set of conversions in virtual bases that we've determined to
// be hidden.
llvm::SmallPtrSet<NamedDecl*, 8> HiddenVBaseCs;
// The set of types hidden by classes derived from this one.
llvm::SmallPtrSet<CanQualType, 8> HiddenTypes;
// Go ahead and collect the direct conversions and add them to the
// hidden-types set.
UnresolvedSetImpl &Cs = *Record->getConversionFunctions();
Output.append(Cs.begin(), Cs.end());
for (UnresolvedSetIterator I = Cs.begin(), E = Cs.end(); I != E; ++I)
HiddenTypes.insert(GetConversionType(Context, I.getDecl()));
// Recursively collect conversions from base classes.
for (CXXRecordDecl::base_class_iterator
I = Record->bases_begin(), E = Record->bases_end(); I != E; ++I) {
const RecordType *RT = I->getType()->getAs<RecordType>();
if (!RT) continue;
CollectVisibleConversions(Context, cast<CXXRecordDecl>(RT->getDecl()),
I->isVirtual(), I->getAccessSpecifier(),
HiddenTypes, Output, VBaseCs, HiddenVBaseCs);
}
// Add any unhidden conversions provided by virtual bases.
for (UnresolvedSetIterator I = VBaseCs.begin(), E = VBaseCs.end();
I != E; ++I) {
if (!HiddenVBaseCs.count(cast<NamedDecl>(I.getDecl()->getCanonicalDecl())))
Output.addDecl(I.getDecl(), I.getAccess());
}
}
/// \brief Give notes for a set of overloads.
///
/// A companion to isExprCallable. In cases when the name that the programmer
/// wrote was an overloaded function, we may be able to make some guesses about
/// plausible overloads based on their return types; such guesses can be handed
/// off to this method to be emitted as notes.
///
/// \param Overloads - The overloads to note.
/// \param FinalNoteLoc - If we've suppressed printing some overloads due to
/// -fshow-overloads=best, this is the location to attach to the note about too
/// many candidates. Typically this will be the location of the original
/// ill-formed expression.
static void noteOverloads(Sema &S, const UnresolvedSetImpl &Overloads,
const SourceLocation FinalNoteLoc) {
int ShownOverloads = 0;
int SuppressedOverloads = 0;
for (UnresolvedSetImpl::iterator It = Overloads.begin(),
DeclsEnd = Overloads.end(); It != DeclsEnd; ++It) {
// FIXME: Magic number for max shown overloads stolen from
// OverloadCandidateSet::NoteCandidates.
if (ShownOverloads >= 4 && S.Diags.getShowOverloads() == Ovl_Best) {
++SuppressedOverloads;
continue;
}
NamedDecl *Fn = (*It)->getUnderlyingDecl();
S.Diag(Fn->getLocation(), diag::note_possible_target_of_call);
++ShownOverloads;
}
if (SuppressedOverloads)
S.Diag(FinalNoteLoc, diag::note_ovl_too_many_candidates)
<< SuppressedOverloads;
}
/// \brief Figure out if an expression could be turned into a call.
///
/// Use this when trying to recover from an error where the programmer may have
/// written just the name of a function instead of actually calling it.
///
/// \param E - The expression to examine.
/// \param ZeroArgCallReturnTy - If the expression can be turned into a call
/// with no arguments, this parameter is set to the type returned by such a
/// call; otherwise, it is set to an empty QualType.
/// \param OverloadSet - If the expression is an overloaded function
/// name, this parameter is populated with the decls of the various overloads.
bool Sema::isExprCallable(const Expr &E, QualType &ZeroArgCallReturnTy,
UnresolvedSetImpl &OverloadSet) {
ZeroArgCallReturnTy = QualType();
OverloadSet.clear();
if (E.getType() == Context.OverloadTy) {
OverloadExpr::FindResult FR = OverloadExpr::find(const_cast<Expr*>(&E));
const OverloadExpr *Overloads = FR.Expression;
for (OverloadExpr::decls_iterator it = Overloads->decls_begin(),
DeclsEnd = Overloads->decls_end(); it != DeclsEnd; ++it) {
OverloadSet.addDecl(*it);
// Check whether the function is a non-template which takes no
// arguments.
if (const FunctionDecl *OverloadDecl
= dyn_cast<FunctionDecl>((*it)->getUnderlyingDecl())) {
if (OverloadDecl->getMinRequiredArguments() == 0)
ZeroArgCallReturnTy = OverloadDecl->getResultType();
}
}
// Ignore overloads that are pointer-to-member constants.
if (FR.HasFormOfMemberPointer)
return false;
return true;
}
if (const DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E.IgnoreParens())) {
if (const FunctionDecl *Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) {
if (Fun->getMinRequiredArguments() == 0)
ZeroArgCallReturnTy = Fun->getResultType();
return true;
}
}
// We don't have an expression that's convenient to get a FunctionDecl from,
// but we can at least check if the type is "function of 0 arguments".
QualType ExprTy = E.getType();
const FunctionType *FunTy = NULL;
QualType PointeeTy = ExprTy->getPointeeType();
if (!PointeeTy.isNull())
FunTy = PointeeTy->getAs<FunctionType>();
if (!FunTy)
FunTy = ExprTy->getAs<FunctionType>();
if (!FunTy && ExprTy == Context.BoundMemberTy) {
// Look for the bound-member type. If it's still overloaded, give up,
// although we probably should have fallen into the OverloadExpr case above
// if we actually have an overloaded bound member.
QualType BoundMemberTy = Expr::findBoundMemberType(&E);
if (!BoundMemberTy.isNull())
FunTy = BoundMemberTy->castAs<FunctionType>();
}
if (const FunctionProtoType *FPT =
dyn_cast_or_null<FunctionProtoType>(FunTy)) {
if (FPT->getNumArgs() == 0)
ZeroArgCallReturnTy = FunTy->getResultType();
return true;
}
return false;
}
