TypeInfo
swift::_getTypeByMangledName(StringRef typeName,
SubstGenericParameterFn substGenericParam) {
Demangler demangler;
NodePointer node;
// Check whether this is the convenience syntax "ModuleName.ClassName".
size_t dotPos = typeName.find('.');
if (dotPos != llvm::StringRef::npos &&
typeName.find('.', dotPos + 1) == llvm::StringRef::npos) {
// Form a demangle tree for this class.
NodePointer classNode = demangler.createNode(Node::Kind::Class);
NodePointer moduleNode = demangler.createNode(Node::Kind::Module,
typeName.substr(0, dotPos));
NodePointer nameNode = demangler.createNode(Node::Kind::Identifier,
typeName.substr(dotPos + 1));
classNode->addChild(moduleNode, demangler);
classNode->addChild(nameNode, demangler);
node = classNode;
} else {
// Demangle the type name.
node = demangler.demangleType(typeName);
if (!node)
return TypeInfo();
}
DecodedMetadataBuilder builder(demangler, substGenericParam,
[](const Metadata *base, StringRef assocType,
const ProtocolDescriptor *protocol) -> const Metadata * {
// Look for a conformance of the base type to the protocol.
auto witnessTable = swift_conformsToProtocol(base, protocol);
if (!witnessTable) return nullptr;
// Look for the named associated type within the protocol.
auto assocTypeReqIndex = findAssociatedTypeByName(protocol, assocType);
if (!assocTypeReqIndex) return nullptr;
// Call the associated type access function.
using AssociatedTypeAccessFn =
const Metadata *(*)(const Metadata *base, const WitnessTable *);
return ((const AssociatedTypeAccessFn *)witnessTable)[*assocTypeReqIndex]
(base, witnessTable);
});
auto type = Demangle::decodeMangledType(builder, node);
return {type, builder.getOwnership()};
}
/// Produce a Demangler value suitable for resolving runtime type metadata
/// strings.
static Demangler getDemanglerForRuntimeTypeResolution() {
Demangler dem;
// Resolve symbolic references to type contexts into the absolute address of
// the type context descriptor, so that if we see a symbolic reference in the
// mangled name we can immediately find the associated metadata.
dem.setSymbolicReferenceResolver([&](int32_t offset,
const void *base) -> NodePointer {
auto absolute_addr = (uintptr_t)detail::applyRelativeOffset(base, offset);
auto reference = dem.createNode(Node::Kind::SymbolicReference, absolute_addr);
auto type = dem.createNode(Node::Kind::Type);
type->addChild(reference, dem);
return type;
});
return dem;
}