Merge pull request #22118 from DougGregor/remote-ast-private-types

[RemoteAST] Improve resolution of private types from metadata

Author: DougGregor

include/swift/ABI/Metadata.h

@@ -2808,22 +2808,80 @@ struct TargetExtensionContextDescriptor final
 
 using ExtensionContextDescriptor = TargetExtensionContextDescriptor<InProcess>;
 
+template<typename Runtime>
+struct TargetMangledContextName {
+  /// The mangled name of the context.
+  TargetRelativeDirectPointer<Runtime, const char, /*nullable*/ false> name;
+};
+
 template<typename Runtime>
 struct TargetAnonymousContextDescriptor final
     : TargetContextDescriptor<Runtime>,
-      TrailingGenericContextObjects<TargetAnonymousContextDescriptor<Runtime>>
+      TrailingGenericContextObjects<TargetAnonymousContextDescriptor<Runtime>,
+                                    TargetGenericContextDescriptorHeader,
+                                    TargetMangledContextName<Runtime>>
 {
 private:
   using TrailingGenericContextObjects
-    = TrailingGenericContextObjects<TargetAnonymousContextDescriptor<Runtime>>;
+    = TrailingGenericContextObjects<TargetAnonymousContextDescriptor<Runtime>,
+                                    TargetGenericContextDescriptorHeader,
+                                    TargetMangledContextName<Runtime>>;
+  using TrailingObjects =
+    typename TrailingGenericContextObjects::TrailingObjects;
+  friend TrailingObjects;
 
 public:
+  using MangledContextName = TargetMangledContextName<Runtime>;
+
   using TrailingGenericContextObjects::getGenericContext;
+  using TrailingGenericContextObjects::getGenericContextHeader;
+  using TrailingGenericContextObjects::getFullGenericContextHeader;
+  using TrailingGenericContextObjects::getGenericParams;
+
+  AnonymousContextDescriptorFlags getAnonymousContextDescriptorFlags() const {
+    return AnonymousContextDescriptorFlags(this->Flags.getKindSpecificFlags());
+  }
 
+  /// Whether this anonymous context descriptor contains a full mangled name,
+  /// which can be used to match the anonymous type to its textual form.
+  bool hasMangledName() const {
+    return getAnonymousContextDescriptorFlags().hasMangledName();
+  }
+
+  /// Retrieve the mangled name of this context, or NULL if it was not
+  /// recorded in the metadata.
+  ConstTargetPointer<Runtime, char> getMangledName() const {
+    if (!hasMangledName())
+      return ConstTargetPointer<Runtime, char>();
+
+    return this->template getTrailingObjects<MangledContextName>()->name;
+  }
+
+  /// Retrieve a pointer to the mangled context name structure.
+  const MangledContextName *getMangledContextName() const {
+    if (!hasMangledName())
+      return nullptr;
+
+    return this->template getTrailingObjects<MangledContextName>();
+  }
+
+private:
+  template<typename T>
+  using OverloadToken =
+    typename TrailingGenericContextObjects::template OverloadToken<T>;
+
+  using TrailingGenericContextObjects::numTrailingObjects;
+
+  size_t numTrailingObjects(OverloadToken<MangledContextName>) const {
+    return this->hasMangledNam() ? 1 : 0;
+  }
+
+public:
   static bool classof(const TargetContextDescriptor<Runtime> *cd) {
     return cd->getKind() == ContextDescriptorKind::Anonymous;
   }
 };
+using AnonymousContextDescriptor = TargetAnonymousContextDescriptor<InProcess>;
 
 /// A protocol descriptor.
 ///

include/swift/ABI/MetadataValues.h

@@ -1344,6 +1344,23 @@ class ProtocolContextDescriptorFlags : public FlagSet<uint16_t> {
                                  setSpecialProtocol)
 };
 
+/// Flags for anonymous type context descriptors. These values are used as the
+/// kindSpecificFlags of the ContextDescriptorFlags for the anonymous context.
+class AnonymousContextDescriptorFlags : public FlagSet<uint16_t> {
+  enum {
+    /// Whether this anonymous context descriptor is followed by its
+    /// mangled name, which can be used to match the descriptor at runtime.
+    HasMangledName = 0,
+  };
+
+public:
+  explicit AnonymousContextDescriptorFlags(uint16_t bits) : FlagSet(bits) {}
+  constexpr AnonymousContextDescriptorFlags() {}
+
+  FLAGSET_DEFINE_FLAG_ACCESSORS(HasMangledName, hasMangledName,
+                                setHasMangledName)
+};
+
 enum class GenericParamKind : uint8_t {
   /// A type parameter.
   Type = 0,

include/swift/AST/IRGenOptions.h

@@ -165,6 +165,9 @@ class IRGenOptions {
   /// Emit names of struct stored properties and enum cases.
   unsigned EnableReflectionNames : 1;
 
+  /// Emit mangled names of anonymous context descriptors.
+  unsigned EnableAnonymousContextMangledNames : 1;
+
   /// Enables resilient class layout.
   unsigned EnableClassResilience : 1;
 
@@ -224,7 +227,8 @@ class IRGenOptions {
         EmitStackPromotionChecks(false), PrintInlineTree(false),
         EmbedMode(IRGenEmbedMode::None), HasValueNamesSetting(false),
         ValueNames(false), EnableReflectionMetadata(true),
-        EnableReflectionNames(true), EnableClassResilience(false),
+        EnableReflectionNames(true), EnableAnonymousContextMangledNames(false),
+        EnableClassResilience(false),
         EnableResilienceBypass(false), LazyInitializeClassMetadata(false),
         UseIncrementalLLVMCodeGen(true), UseSwiftCall(false),
         GenerateProfile(false), EnableDynamicReplacementChaining(false),

include/swift/Option/FrontendOptions.td

@@ -272,6 +272,10 @@ def disable_llvm_value_names : Flag<["-"], "disable-llvm-value-names">,
 def enable_llvm_value_names : Flag<["-"], "enable-llvm-value-names">,
   HelpText<"Add names to local values in LLVM IR">;
 
+def enable_anonymous_context_mangled_names :
+  Flag<["-"], "enable-anonymous-context-mangled-names">,
+  HelpText<"Enable emission of mangled names in anonymous context descriptors">;
+
 def disable_reflection_metadata : Flag<["-"], "disable-reflection-metadata">,
   HelpText<"Disable emission of reflection metadata for nominal types">;