[swift-inspect] Add an option to print mangled names while dumping generic metadata.

Author: w6sec

include/swift/Remote/MetadataReader.h

@@ -3116,7 +3116,8 @@ class MetadataReader {
         break;
 
       case GenericParamKind::TypePack:
-        assert(false && "Packs not supported here yet");
+        // assert(false && "Packs not supported here yet");
+        return {};
 
       default:
         // We don't know about this kind of parameter.

include/swift/RemoteInspection/ReflectionContext.h

@@ -853,24 +853,25 @@ class ReflectionContext
 
   /// Returns true if the address is known to the reflection context.
   /// Currently, that means that either the address falls within the text or
-  /// data segments of a registered image, or the address points to a Metadata
-  /// whose type context descriptor is within the text segment of a registered
-  /// image.
-  bool ownsAddress(RemoteAddress Address) {
+  /// data segments of a registered image, or optionally, the address points
+  /// to a Metadata whose type context descriptor is within the text segment
+  /// of a registered image.
+  bool ownsAddress(RemoteAddress Address, bool checkMetadataDescriptor = true) {
     if (ownsAddress(Address, textRanges))
       return true;
     if (ownsAddress(Address, dataRanges))
       return true;
 
-    // This is usually called on a Metadata address which might have been
-    // on the heap. Try reading it and looking up its type context descriptor
-    // instead.
-    if (auto Metadata = readMetadata(Address.getAddressData()))
-      if (auto DescriptorAddress =
-          super::readAddressOfNominalTypeDescriptor(Metadata, true))
-        if (ownsAddress(RemoteAddress(DescriptorAddress), textRanges))
-          return true;
-
+    if (checkMetadataDescriptor) {
+      // This is usually called on a Metadata address which might have been
+      // on the heap. Try reading it and looking up its type context descriptor
+      // instead.
+      if (auto Metadata = readMetadata(Address.getAddressData()))
+        if (auto DescriptorAddress =
+            super::readAddressOfNominalTypeDescriptor(Metadata, true))
+          if (ownsAddress(RemoteAddress(DescriptorAddress), textRanges))
+            return true;
+    }
     return false;
   }
 

include/swift/SwiftRemoteMirror/SwiftRemoteMirror.h

@@ -138,6 +138,15 @@ SWIFT_REMOTE_MIRROR_LINKAGE
 int
 swift_reflection_ownsAddress(SwiftReflectionContextRef ContextRef, uintptr_t Address);
 
+/// Returns whether the given address is strictly in the DATA, AUTH or TEXT
+/// segments of the image added to this library. Images must be added using
+/// swift_reflection_addImage, not swift_reflection_addReflectionInfo, for this
+/// function to work properly. If addReflectionInfo is used, the return value
+/// will always be false.
+SWIFT_REMOTE_MIRROR_LINKAGE
+int
+swift_reflection_ownsAddressStrict(SwiftReflectionContextRef ContextRef, uintptr_t Address);
+
 /// Returns the metadata pointer for a given object.
 SWIFT_REMOTE_MIRROR_LINKAGE
 uintptr_t
@@ -179,6 +188,7 @@ swift_reflection_typeRefForMangledTypeName(SwiftReflectionContextRef ContextRef,
 ///
 /// The returned string is heap allocated and the caller must free() it when
 /// done.
+[[deprecated("Please use swift_reflection_copyNameForTypeRef()")]]
 SWIFT_REMOTE_MIRROR_LINKAGE
 char *
 swift_reflection_copyDemangledNameForTypeRef(
@@ -189,6 +199,18 @@ char *
 swift_reflection_copyDemangledNameForProtocolDescriptor(
   SwiftReflectionContextRef ContextRef, swift_reflection_ptr_t Proto);
 
+/// Returns the mangled or demangled name for a typeref, or NULL if the name
+/// couldn't be created.
+///
+/// The returned string is heap allocated and the caller must free() it when
+/// done.
+
+SWIFT_REMOTE_MIRROR_LINKAGE
+char*
+swift_reflection_copyNameForTypeRef(SwiftReflectionContextRef ContextRef,
+                                    swift_typeref_t OpaqueTypeRef,
+                                    bool mangled);
+
 /// Returns a structure describing the layout of a value of a typeref.
 /// For classes, this returns the reference value itself.
 SWIFT_REMOTE_MIRROR_LINKAGE

stdlib/public/SwiftRemoteMirror/SwiftRemoteMirror.cpp

@@ -314,6 +314,12 @@ swift_reflection_ownsAddress(SwiftReflectionContextRef ContextRef, uintptr_t Add
   return Context->ownsAddress(RemoteAddress(Address));
 }
 
+int
+swift_reflection_ownsAddressStrict(SwiftReflectionContextRef ContextRef, uintptr_t Address) {
+  auto Context = ContextRef->nativeContext;
+  return Context->ownsAddress(RemoteAddress(Address), false);
+}
+
 uintptr_t
 swift_reflection_metadataForObject(SwiftReflectionContextRef ContextRef,
                                    uintptr_t Object) {
@@ -367,6 +373,26 @@ swift_reflection_copyDemangledNameForTypeRef(
   return strdup(Name.c_str());
 }
 
+char *
+swift_reflection_copyNameForTypeRef(SwiftReflectionContextRef ContextRef,
+                                    swift_typeref_t OpaqueTypeRef,
+                                    bool mangled) {
+  auto TR = reinterpret_cast<const TypeRef *>(OpaqueTypeRef);
+
+  Demangle::Demangler Dem;
+  if (mangled) {
+    auto Mangling = mangleNode(TR->getDemangling(Dem));
+    if (Mangling.isSuccess()) {
+      return strdup(Mangling.result().c_str());
+    }
+  }
+  else {
+    auto Name = nodeToString(TR->getDemangling(Dem));
+    return strdup(Name.c_str());
+  }
+  return nullptr;
+}
+
 SWIFT_REMOTE_MIRROR_LINKAGE
 char *
 swift_reflection_copyDemangledNameForProtocolDescriptor(
@@ -697,7 +723,7 @@ void swift_reflection_dumpInfoForTypeRef(SwiftReflectionContextRef ContextRef,
     }
 
     char *DemangledName =
-        swift_reflection_copyDemangledNameForTypeRef(ContextRef, OpaqueTypeRef);
+        swift_reflection_copyNameForTypeRef(ContextRef, OpaqueTypeRef, false);
     std::cout << "Demangled name: " << DemangledName << "\n";
     free(DemangledName);
   }

tools/swift-inspect/Sources/swift-inspect/Operations/DumpGenericMetadata.swift

@@ -33,6 +33,9 @@ internal struct DumpGenericMetadata: ParsableCommand {
   @OptionGroup()
   var backtraceOptions: BacktraceOptions
 
+  @OptionGroup()
+  var genericMetadataOptions: GenericMetadataOptions
+
   func run() throws {
     try inspect(options: options) { process in
       let allocations: [swift_metadata_allocation_t] =
@@ -43,9 +46,8 @@ internal struct DumpGenericMetadata: ParsableCommand {
         if pointer == 0 { return nil }
 
         return Metadata(ptr: pointer,
-                        allocation: allocations.last(where: { pointer >= $0.ptr }),
-                        name: process.context.name(type: pointer) ??
-                        "<unknown>",
+                        allocation: allocations.last(where: { pointer >= $0.ptr && pointer < $0.ptr + UInt64($0.size) }),
+                        name: (process.context.name(type: pointer, mangled: genericMetadataOptions.mangled) ?? "<unknown>"),
                         isArrayOfClass: process.context.isArrayOfClass(pointer))
       }
 
@@ -54,12 +56,17 @@ internal struct DumpGenericMetadata: ParsableCommand {
               ? nil
               : try process.context.allocationStacks
 
+      var errorneousMetadata: [(ptr: swift_reflection_ptr_t, name: String)] = []
+
       print("Address", "Allocation", "Size", "Offset", "isArrayOfClass", "Name", separator: "\t")
       generics.forEach {
         print("\(hex: $0.ptr)", terminator: "\t")
         if let allocation = $0.allocation, let offset = $0.offset {
           print("\(hex: allocation.ptr)\t\(allocation.size)\t\(offset)", terminator: "\t")
         } else {
+          if (swift_reflection_ownsAddressStrict(process.context, UInt($0.ptr))) == 0 {
+            errorneousMetadata.append((ptr: $0.ptr, name: $0.name))
+          }
           print("???\t??\t???", terminator: "\t")
         }
         print($0.isArrayOfClass, terminator: "\t")
@@ -72,6 +79,14 @@ internal struct DumpGenericMetadata: ParsableCommand {
           }
         }
       }
+
+      if errorneousMetadata.count > 0 {
+        print("Error: The following metadata was not found in any DATA or AUTH segments, may be garbage.")
+        errorneousMetadata.forEach {
+          print("\(hex: $0.ptr)\t\($0.name)")
+        }
+      }
+
     }
   }
 }

tools/swift-inspect/Sources/swift-inspect/RemoteMirror+Extensions.swift

@@ -64,11 +64,11 @@ extension SwiftReflectionContextRef {
     }
   }
 
-  internal func name(type: swift_reflection_ptr_t) -> String? {
+  internal func name(type: swift_reflection_ptr_t, mangled: Bool = false) -> String? {
     let typeref = swift_reflection_typeRefForMetadata(self, UInt(type))
     if typeref == 0 { return nil }
 
-    guard let name = swift_reflection_copyDemangledNameForTypeRef(self, typeref) else {
+    guard let name = swift_reflection_copyNameForTypeRef(self, typeref, mangled) else {
       return nil
     }
     defer { free(name) }

tools/swift-inspect/Sources/swift-inspect/main.swift

@@ -42,6 +42,10 @@ internal struct BacktraceOptions: ParsableArguments {
   }
 }
 
+internal struct GenericMetadataOptions: ParsableArguments {
+  @Flag(help: "Show allocations in mangled form")
+  var mangled: Bool = false
+}
 
 internal func inspect(options: UniversalOptions,
                       _ body: (any RemoteProcess) throws -> Void) throws {