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AzoyAzoy
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Implement an SPI to iterate types who conform to some protocol
Incorporate feedback
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8 files changed

+410
-1
lines changed

8 files changed

+410
-1
lines changed

‎stdlib/public/Reflection/Sources/Reflection/CMakeLists.txt

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@@ -17,6 +17,7 @@ list(APPEND SWIFT_REFLECTION_SWIFT_FLAGS
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add_swift_target_library(swiftReflection ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES} IS_STDLIB
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Case.swift
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Conformances.swift
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Field.swift
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GenericArguments.swift
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KeyPath.swift

‎stdlib/public/Reflection/Sources/Reflection/Conformances.swift

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//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2023 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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//
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//===----------------------------------------------------------------------===//
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#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
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import Swift
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import _Runtime
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@available(SwiftStdlib 5.9, *)
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@_silgen_name("_swift_reflection_withConformanceCache")
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func _withConformanceCache(
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_ proto: ProtocolDescriptor,
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_ context: UnsafeMutableRawPointer,
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_ callback: @convention(c) (
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/* Array of types */ UnsafePointer<UnsafeRawPointer>,
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/* Number of types */ Int,
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/* Context we just passed */ UnsafeMutableRawPointer
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) -> ()
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)
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@available(SwiftStdlib 5.9, *)
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@_spi(Reflection)
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public func _typesThatConform(to type: Any.Type) -> [Any.Type]? {
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let meta = Metadata(type)
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guard meta.kind == .existential else {
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return nil
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}
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let existential = meta.existential
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let protos = existential.protocols
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guard protos.count == 1 else {
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return nil
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}
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let proto = protos[0]
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var result: [Any.Type] = []
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withUnsafeMutablePointer(to: &result) {
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_withConformanceCache(proto, UnsafeMutableRawPointer($0)) {
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let buffer = UnsafeBufferPointer<Any.Type>(
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start: UnsafePointer<Any.Type>($0._rawValue),
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count: $1
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)
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let arrayPtr = $2.assumingMemoryBound(to: [Any.Type].self)
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arrayPtr.pointee = Array(buffer)
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}
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}
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return result
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}
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#endif

‎stdlib/public/Reflection/Sources/_Runtime/CMakeLists.txt

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@@ -64,10 +64,12 @@ add_swift_target_library(swift_Runtime ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES} IS_ST
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Utils/RelativePointer.swift
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Utils/TypeCache.swift
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Caches.cpp
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ConformanceDescriptor.swift
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ExistentialContainer.swift
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Functions.swift
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HeapObject.swift
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ImageInspection.cpp
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WitnessTable.swift
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C_COMPILE_FLAGS

‎stdlib/public/Reflection/Sources/_Runtime/Caches.cpp

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//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2023 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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//
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//===----------------------------------------------------------------------===//
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// Only as SPI for Darwin platforms for right now...
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#if defined(__MACH__)
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#include "ImageInspection.h"
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#include "swift/ABI/Metadata.h"
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#include "swift/Basic/Lazy.h"
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#include "swift/Runtime/Concurrent.h"
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#include "swift/Runtime/Config.h"
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#include <cstdint>
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#include <unordered_map>
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using namespace swift;
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//===----------------------------------------------------------------------===//
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// Protocol Conformance Cache
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//===----------------------------------------------------------------------===//
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namespace {
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struct ConformanceSection {
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const ProtocolConformanceRecord *Begin, *End;
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ConformanceSection(const ProtocolConformanceRecord *begin,
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const ProtocolConformanceRecord *end)
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: Begin(begin), End(end) {}
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ConformanceSection(const void *ptr, uintptr_t size) {
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auto bytes = reinterpret_cast<const char *>(ptr);
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Begin = reinterpret_cast<const ProtocolConformanceRecord *>(ptr);
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End = reinterpret_cast<const ProtocolConformanceRecord *>(bytes + size);
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}
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const ProtocolConformanceRecord *begin() const {
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return Begin;
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}
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const ProtocolConformanceRecord *end() const {
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return End;
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}
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};
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}
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struct ConformanceCache {
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// All accesses to Cache and LastSectionCount must be within CacheMutex's
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// lock scope.
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std::unordered_map<
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/* Key */ const ProtocolDescriptor *,
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/* Value */ std::vector<const Metadata *>
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> Cache;
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Mutex CacheMutex;
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ConcurrentReadableArray<ConformanceSection> Sections;
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size_t LastSectionCount = 0;
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ConformanceCache() {
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initializeConformanceLookup();
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}
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};
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static Lazy<ConformanceCache> Conformances;
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void swift::registerConformances(const void *baseAddress,
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const void *conformances,
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uintptr_t conformancesSize) {
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// Conformance cache should always be sufficiently initialized by this point.
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auto &C = Conformances.unsafeGetAlreadyInitialized();
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C.Sections.push_back(ConformanceSection{conformances, conformancesSize});
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}
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static const Metadata *_getCanonicalTypeMetadata(
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const ProtocolConformanceDescriptor *conformance) {
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switch (conformance->getTypeKind()) {
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case TypeReferenceKind::DirectTypeDescriptor:
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case TypeReferenceKind::IndirectTypeDescriptor: {
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if (auto anyType = conformance->getTypeDescriptor()) {
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if (auto type = dyn_cast<TypeContextDescriptor>(anyType)) {
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if (!type->isGeneric()) {
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if (auto accessFn = type->getAccessFunction()) {
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return accessFn(MetadataState::Abstract).Value;
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}
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}
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}
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}
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return nullptr;
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}
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case TypeReferenceKind::DirectObjCClassName:
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case TypeReferenceKind::IndirectObjCClass:
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return nullptr;
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}
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}
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using ConformanceCacheCallback = void (*)(const Metadata **,
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size_t, void *);
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SWIFT_RUNTIME_STDLIB_SPI SWIFT_CC(swift)
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void _swift_reflection_withConformanceCache(const ProtocolDescriptor *proto,
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void *context,
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ConformanceCacheCallback callback) {
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auto &C = Conformances.get();
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auto snapshot = C.Sections.snapshot();
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Mutex::ScopedLock lock(C.CacheMutex);
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if (C.LastSectionCount > 0 && snapshot.count() <= C.LastSectionCount) {
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auto entry = C.Cache.find(proto);
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if (entry != C.Cache.end()) {
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callback(entry->second.data(), entry->second.size(), context);
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return;
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}
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}
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std::vector<const Metadata *> types = {};
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for (auto &section : snapshot) {
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for (auto &record : section) {
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auto conformance = record.get();
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if (conformance->getProtocol() != proto) {
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continue;
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}
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if (conformance->hasConditionalRequirements()) {
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continue;
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}
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if (auto type = _getCanonicalTypeMetadata(conformance)) {
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types.push_back(type);
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}
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}
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}
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callback(types.data(), types.size(), context);
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C.Cache[proto] = types;
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C.LastSectionCount = snapshot.count();
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}
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#endif

‎stdlib/public/Reflection/Sources/_Runtime/ImageInspection.cpp

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//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2023 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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//
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//===----------------------------------------------------------------------===//
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#include "ImageInspection.h"
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//===----------------------------------------------------------------------===//
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// Mach-O Image Inspection
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//===----------------------------------------------------------------------===//
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#if defined(__MACH__)
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#include "swift/Runtime/Config.h"
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#include "swift/Threading/Once.h"
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#include <mach-o/dyld.h>
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#include <mach-o/getsect.h>
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#include <objc/runtime.h>
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#include <stdint.h>
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#if __POINTER_WIDTH__ == 64
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using mach_header_platform = mach_header_64;
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#else
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using mach_header_platform = mach_header;
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#endif
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template <const char *SEGMENT_NAME, const char *SECTION_NAME,
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void CONSUME_BLOCK(const void *baseAddress,
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const void *start, uintptr_t size)>
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void addImageCallback(const mach_header *mh) {
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#if __POINTER_WIDTH__ == 64
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assert(mh->magic == MH_MAGIC_64 && "loaded non-64-bit image?!");
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#endif
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// Look for a __swift5_proto section.
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unsigned long size;
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const uint8_t *section =
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getsectiondata(reinterpret_cast<const mach_header_platform *>(mh),
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SEGMENT_NAME, SECTION_NAME,
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&size);
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if (!section)
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return;
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CONSUME_BLOCK(mh, section, size);
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}
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template <const char *SEGMENT_NAME, const char *SECTION_NAME,
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void CONSUME_BLOCK(const void *baseAddress,
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const void *start, uintptr_t size)>
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void addImageCallback(const mach_header *mh, intptr_t vmaddr_slide) {
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addImageCallback<SEGMENT_NAME, SECTION_NAME, CONSUME_BLOCK>(mh);
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}
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#if OBJC_ADDLOADIMAGEFUNC_DEFINED && SWIFT_OBJC_INTEROP
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#define REGISTER_FUNC(...) \
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if (__builtin_available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)) { \
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objc_addLoadImageFunc(__VA_ARGS__); \
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} else { \
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_dyld_register_func_for_add_image(__VA_ARGS__); \
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}
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#else
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#define REGISTER_FUNC(...) _dyld_register_func_for_add_image(__VA_ARGS__)
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#endif
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// WARNING: the callbacks are called from unsafe contexts (with the dyld and
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// ObjC runtime locks held) and must be very careful in what they do. Locking
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// must be arranged to avoid deadlocks (other code must never call out to dyld
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// or ObjC holding a lock that gets taken in one of these callbacks) and the
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// new/delete operators must not be called, in case a program supplies an
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// overload which does not cooperate with these requirements.
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void swift::initializeConformanceLookup() {
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REGISTER_FUNC(addImageCallback<TextSegment, ProtocolConformancesSection,
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registerConformances>);
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}
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#endif

‎stdlib/public/Reflection/Sources/_Runtime/ImageInspection.h

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//===----------------------------------------------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2023 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_REFLECTION_IMAGE_INSPECTION_H
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#define SWIFT_REFLECTION_IMAGE_INSPECTION_H
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#include "swift/Runtime/Config.h"
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#include <cstdint>
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#if defined(__MACH__)
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/// The Mach-O section name for the section containing protocol descriptor
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/// references. This lives within SEG_TEXT.
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#define MachOProtocolsSection "__swift5_protos"
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/// The Mach-O section name for the section containing protocol conformances.
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/// This lives within SEG_TEXT.
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#define MachOProtocolConformancesSection "__swift5_proto"
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/// The Mach-O section name for the section containing type references.
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/// This lives within SEG_TEXT.
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#define MachOTypeMetadataRecordSection "__swift5_types"
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/// The Mach-O section name for the section containing dynamic replacements.
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/// This lives within SEG_TEXT.
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#define MachODynamicReplacementSection "__swift5_replace"
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#define MachODynamicReplacementSomeSection "__swift5_replac2"
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/// The Mach-O section name for the section containing accessible functions.
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/// This lives within SEG_TEXT.
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#define MachOAccessibleFunctionsSection "__swift5_acfuncs"
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#define MachOTextSegment "__TEXT"
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constexpr const char ProtocolsSection[] = MachOProtocolsSection;
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constexpr const char ProtocolConformancesSection[] =
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MachOProtocolConformancesSection;
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constexpr const char TypeMetadataRecordSection[] =
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MachOTypeMetadataRecordSection;
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constexpr const char DynamicReplacementSection[] =
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MachODynamicReplacementSection;
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constexpr const char DynamicReplacementSomeSection[] =
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MachODynamicReplacementSomeSection;
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constexpr const char AccessibleFunctionsSection[] =
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MachOAccessibleFunctionsSection;
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constexpr const char TextSegment[] = MachOTextSegment;
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#endif
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namespace swift {
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void initializeConformanceLookup();
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void registerConformances(const void *baseAddress, const void *conformances,
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uintptr_t conformancesSize);
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} // namespace swift
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#endif

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