// Returns a desugared version of the QualType, and marks ShouldAKA as true
// whenever we remove significant sugar from the type.
static QualType Desugar(ASTContext &Context, QualType QT, bool &ShouldAKA) {
QualifierCollector QC;
while (true) {
const Type *Ty = QC.strip(QT);
// Don't aka just because we saw an elaborated type...
if (const ElaboratedType *ET = dyn_cast<ElaboratedType>(Ty)) {
QT = ET->desugar();
continue;
}
// ... or a paren type ...
if (const ParenType *PT = dyn_cast<ParenType>(Ty)) {
QT = PT->desugar();
continue;
}
// ...or a substituted template type parameter ...
if (const SubstTemplateTypeParmType *ST =
dyn_cast<SubstTemplateTypeParmType>(Ty)) {
QT = ST->desugar();
continue;
}
// ...or an attributed type...
if (const AttributedType *AT = dyn_cast<AttributedType>(Ty)) {
QT = AT->desugar();
continue;
}
// ... or an auto type.
if (const AutoType *AT = dyn_cast<AutoType>(Ty)) {
if (!AT->isSugared())
break;
QT = AT->desugar();
continue;
}
// Don't desugar template specializations.
if (isa<TemplateSpecializationType>(Ty))
break;
// Don't desugar magic Objective-C types.
if (QualType(Ty,0) == Context.getObjCIdType() ||
QualType(Ty,0) == Context.getObjCClassType() ||
QualType(Ty,0) == Context.getObjCSelType() ||
QualType(Ty,0) == Context.getObjCProtoType())
break;
// Don't desugar va_list.
if (QualType(Ty,0) == Context.getBuiltinVaListType())
break;
// Otherwise, do a single-step desugar.
QualType Underlying;
bool IsSugar = false;
switch (Ty->getTypeClass()) {
#define ABSTRACT_TYPE(Class, Base)
#define TYPE(Class, Base) \
case Type::Class: { \
const Class##Type *CTy = cast<Class##Type>(Ty); \
if (CTy->isSugared()) { \
IsSugar = true; \
Underlying = CTy->desugar(); \
} \
break; \
}
#include "clang/AST/TypeNodes.def"
}
// If it wasn't sugared, we're done.
if (!IsSugar)
break;
// If the desugared type is a vector type, we don't want to expand
// it, it will turn into an attribute mess. People want their "vec4".
if (isa<VectorType>(Underlying))
break;
// Don't desugar through the primary typedef of an anonymous type.
if (const TagType *UTT = Underlying->getAs<TagType>())
if (const TypedefType *QTT = dyn_cast<TypedefType>(QT))
if (UTT->getDecl()->getTypedefForAnonDecl() == QTT->getDecl())
break;
// Record that we actually looked through an opaque type here.
ShouldAKA = true;
QT = Underlying;
}
// If we have a pointer-like type, desugar the pointee as well.
// FIXME: Handle other pointer-like types.
if (const PointerType *Ty = QT->getAs<PointerType>()) {
QT = Context.getPointerType(Desugar(Context, Ty->getPointeeType(),
ShouldAKA));
} else if (const LValueReferenceType *Ty = QT->getAs<LValueReferenceType>()) {
QT = Context.getLValueReferenceType(Desugar(Context, Ty->getPointeeType(),
ShouldAKA));
} else if (const RValueReferenceType *Ty = QT->getAs<RValueReferenceType>()) {
QT = Context.getRValueReferenceType(Desugar(Context, Ty->getPointeeType(),
ShouldAKA));
}
return QC.apply(Context, QT);
}
/// Determines whether we should have an a.k.a. clause when
/// pretty-printing a type. There are three main criteria:
///
/// 1) Some types provide very minimal sugar that doesn't impede the
/// user's understanding --- for example, elaborated type
/// specifiers. If this is all the sugar we see, we don't want an
/// a.k.a. clause.
/// 2) Some types are technically sugared but are much more familiar
/// when seen in their sugared form --- for example, va_list,
/// vector types, and the magic Objective C types. We don't
/// want to desugar these, even if we do produce an a.k.a. clause.
/// 3) Some types may have already been desugared previously in this diagnostic.
/// if this is the case, doing another "aka" would just be clutter.
///
static bool ShouldAKA(ASTContext &Context, QualType QT,
const Diagnostic::ArgumentValue *PrevArgs,
unsigned NumPrevArgs,
QualType &DesugaredQT) {
QualType InputTy = QT;
bool AKA = false;
QualifierCollector Qc;
while (true) {
const Type *Ty = Qc.strip(QT);
// Don't aka just because we saw an elaborated type...
if (isa<ElaboratedType>(Ty)) {
QT = cast<ElaboratedType>(Ty)->desugar();
continue;
}
// ...or a qualified name type...
if (isa<QualifiedNameType>(Ty)) {
QT = cast<QualifiedNameType>(Ty)->desugar();
continue;
}
// ...or an injected class name...
if (isa<InjectedClassNameType>(Ty)) {
QT = cast<InjectedClassNameType>(Ty)->desugar();
continue;
}
// ...or a substituted template type parameter.
if (isa<SubstTemplateTypeParmType>(Ty)) {
QT = cast<SubstTemplateTypeParmType>(Ty)->desugar();
continue;
}
// Don't desugar template specializations.
if (isa<TemplateSpecializationType>(Ty))
break;
// Don't desugar magic Objective-C types.
if (QualType(Ty,0) == Context.getObjCIdType() ||
QualType(Ty,0) == Context.getObjCClassType() ||
QualType(Ty,0) == Context.getObjCSelType() ||
QualType(Ty,0) == Context.getObjCProtoType())
break;
// Don't desugar va_list.
if (QualType(Ty,0) == Context.getBuiltinVaListType())
break;
// Otherwise, do a single-step desugar.
QualType Underlying;
bool IsSugar = false;
switch (Ty->getTypeClass()) {
#define ABSTRACT_TYPE(Class, Base)
#define TYPE(Class, Base) \
case Type::Class: { \
const Class##Type *CTy = cast<Class##Type>(Ty); \
if (CTy->isSugared()) { \
IsSugar = true; \
Underlying = CTy->desugar(); \
} \
break; \
}
#include "clang/AST/TypeNodes.def"
}
// If it wasn't sugared, we're done.
if (!IsSugar)
break;
// If the desugared type is a vector type, we don't want to expand
// it, it will turn into an attribute mess. People want their "vec4".
if (isa<VectorType>(Underlying))
break;
// Don't desugar through the primary typedef of an anonymous type.
if (isa<TagType>(Underlying) && isa<TypedefType>(QT))
if (cast<TagType>(Underlying)->getDecl()->getTypedefForAnonDecl() ==
cast<TypedefType>(QT)->getDecl())
break;
// Otherwise, we're tearing through something opaque; note that
// we'll eventually need an a.k.a. clause and keep going.
AKA = true;
QT = Underlying;
continue;
}
// If we never tore through opaque sugar, don't print aka.
if (!AKA) return false;
// If we did, check to see if we already desugared this type in this
// diagnostic. If so, don't do it again.
for (unsigned i = 0; i != NumPrevArgs; ++i) {
// TODO: Handle ak_declcontext case.
if (PrevArgs[i].first == Diagnostic::ak_qualtype) {
void *Ptr = (void*)PrevArgs[i].second;
QualType PrevTy(QualType::getFromOpaquePtr(Ptr));
if (PrevTy == InputTy)
return false;
}
}
DesugaredQT = Qc.apply(QT);
return true;
}