/// Normalize a mangled name so it can be matched with string equality.
static std::string normalizeReflectionName(Demangler &dem, StringRef reflectionName) {
reflectionName = dropSwiftManglingPrefix(reflectionName);
// Remangle the reflection name to resolve symbolic references.
if (auto node = dem.demangleType(reflectionName)) {
return mangleNode(node);
}
// Fall back to the raw string.
return reflectionName;
}
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()};
}
void swift::gatherWrittenGenericArgs(
const Metadata *metadata,
const TypeContextDescriptor *description,
std::vector<const Metadata *> &allGenericArgs) {
auto generics = description->getGenericContext();
if (!generics)
return;
bool missingWrittenArguments = false;
auto genericArgs = description->getGenericArguments(metadata);
for (auto param : generics->getGenericParams()) {
switch (param.getKind()) {
case GenericParamKind::Type:
// The type should have a key argument unless it's been same-typed to
// another type.
if (param.hasKeyArgument()) {
auto genericArg = *genericArgs++;
allGenericArgs.push_back(genericArg);
} else {
// Leave a gap for us to fill in by looking at same type info.
allGenericArgs.push_back(nullptr);
missingWrittenArguments = true;
}
// We don't know about type parameters with extra arguments. Leave
// a hole for it.
if (param.hasExtraArgument()) {
allGenericArgs.push_back(nullptr);
++genericArgs;
}
break;
default:
// We don't know about this kind of parameter. Create placeholders where
// needed.
if (param.hasKeyArgument()) {
allGenericArgs.push_back(nullptr);
++genericArgs;
}
if (param.hasExtraArgument()) {
allGenericArgs.push_back(nullptr);
++genericArgs;
}
break;
}
}
// If there is no follow-up work to do, we're done.
if (!missingWrittenArguments)
return;
// We have generic arguments that would be written, but have been
// canonicalized away. Use same-type requirements to reconstitute them.
// Retrieve the mapping information needed for depth/index -> flat index.
std::vector<unsigned> genericParamCounts;
(void)_gatherGenericParameterCounts(description, genericParamCounts);
// Walk through the generic requirements to evaluate same-type
// constraints that are needed to fill in missing generic arguments.
for (const auto &req : generics->getGenericRequirements()) {
// We only care about same-type constraints.
if (req.Flags.getKind() != GenericRequirementKind::SameType)
continue;
// Where the left-hand side is a generic parameter.
if (req.Param.begin() != req.Param.end())
continue;
// If we don't yet have an argument for this parameter, it's a
// same-type-to-concrete constraint.
unsigned lhsFlatIndex = req.Param.getRootParamIndex();
if (lhsFlatIndex >= allGenericArgs.size())
continue;
if (!allGenericArgs[lhsFlatIndex]) {
// Substitute into the right-hand side.
SubstGenericParametersFromWrittenArgs substitutions(allGenericArgs,
genericParamCounts);
allGenericArgs[lhsFlatIndex] =
_getTypeByMangledName(req.getMangledTypeName(), substitutions);
continue;
}
// If we do have an argument for this parameter, it might be that
// the right-hand side is itself a generic parameter, which means
// we have a same-type constraint A == B where A is already filled in.
Demangler demangler;
NodePointer node = demangler.demangleType(req.getMangledTypeName());
if (!node)
continue;
// Find the flat index that the right-hand side refers to.
if (node->getKind() == Demangle::Node::Kind::Type)
node = node->getChild(0);
if (node->getKind() != Demangle::Node::Kind::DependentGenericParamType)
continue;
auto rhsFlatIndex =
_depthIndexToFlatIndex(node->getChild(0)->getIndex(),
node->getChild(1)->getIndex(),
genericParamCounts);
if (!rhsFlatIndex || *rhsFlatIndex >= allGenericArgs.size())
continue;
if (allGenericArgs[*rhsFlatIndex] || !allGenericArgs[lhsFlatIndex])
continue;
allGenericArgs[*rhsFlatIndex] = allGenericArgs[lhsFlatIndex];
}
}