Refactor named metadata now that it is a first-class type

Author: CodaFi

Sources/LLVM/Module.swift

@@ -242,6 +242,18 @@ public final class Module: CustomStringConvertible {
     }
   }
 
+  /// Retrieves the first alias in this module, if there are any aliases.
+  public var firstAlias: Alias? {
+    guard let fn = LLVMGetFirstGlobalAlias(llvm) else { return nil }
+    return Alias(llvm: fn)
+  }
+
+  /// Retrieves the last alias in this module, if there are any aliases.
+  public var lastAlias: Alias? {
+    guard let fn = LLVMGetLastGlobalAlias(llvm) else { return nil }
+    return Alias(llvm: fn)
+  }
+
   /// Retrieves the sequence of aliases that make up this module.
   public var aliases: AnySequence<Alias> {
     var current = firstAlias
@@ -254,15 +266,26 @@ public final class Module: CustomStringConvertible {
   }
 
   /// Retrieves the first alias in this module, if there are any aliases.
-  public var firstAlias: Alias? {
-    guard let fn = LLVMGetFirstGlobalAlias(llvm) else { return nil }
-    return Alias(llvm: fn)
+  public var firstNamedMetadata: NamedMetadata? {
+    guard let fn = LLVMGetFirstNamedMetadata(llvm) else { return nil }
+    return NamedMetadata(module: self, llvm: fn)
   }
 
   /// Retrieves the last alias in this module, if there are any aliases.
-  public var lastAlias: Alias? {
-    guard let fn = LLVMGetLastGlobalAlias(llvm) else { return nil }
-    return Alias(llvm: fn)
+  public var lastNamedMetadata: NamedMetadata? {
+    guard let fn = LLVMGetLastNamedMetadata(llvm) else { return nil }
+    return NamedMetadata(module: self, llvm: fn)
+  }
+
+  /// Retrieves the sequence of aliases that make up this module.
+  public var namedMetadata: AnySequence<NamedMetadata> {
+    var current = firstNamedMetadata
+    return AnySequence<NamedMetadata> {
+      return AnyIterator<NamedMetadata> {
+        defer { current = current?.next() }
+        return current
+      }
+    }
   }
 
   /// The current debug metadata version number.
@@ -375,7 +398,7 @@ extension Module {
   /// - returns: A representation of the newly created metadata with the
   ///   given name.
   public func metadata(named name: String) -> NamedMetadata {
-    return NamedMetadata(module: self, name: name)
+    return NamedMetadata(module: self, llvm: LLVMGetOrInsertNamedMetadata(self.llvm, name, name.count))
   }
 
   /// Build a named global of the given type.

Sources/LLVM/NamedMetadata.swift

@@ -11,9 +11,28 @@ public class NamedMetadata {
   /// The name associated with this named metadata.
   public let name: String
 
-  init(module: Module, name: String) {
+  private let llvm: LLVMNamedMDNodeRef
+
+  init(module: Module, llvm: LLVMNamedMDNodeRef) {
     self.module = module
-    self.name = name
+    self.llvm = llvm
+    var nameLen = 0
+    guard let rawName = LLVMGetNamedMetadataName(llvm, &nameLen) else {
+      fatalError("Could not retrieve name for named MD node?")
+    }
+    self.name = String(cString: rawName)
+  }
+
+  /// Retrieves the previous alias in the module, if there is one.
+  public func previous() -> NamedMetadata? {
+    guard let previous = LLVMGetPreviousNamedMetadata(llvm) else { return nil }
+    return NamedMetadata(module: self.module, llvm: previous)
+  }
+
+  /// Retrieves the next alias in the module, if there is one.
+  public func next() -> NamedMetadata? {
+    guard let next = LLVMGetNextNamedMetadata(llvm) else { return nil }
+    return NamedMetadata(module: self.module,llvm: next)
   }
 
   /// Computes the operands of a named metadata node.