Allow adding globals at the level of a module

Sources/LLVM/IRBuilder.swift

@@ -352,6 +352,71 @@ extension Module {
     guard let comdat = LLVMGetOrInsertComdat(llvm, name) else { fatalError() }
     return Comdat(llvm: comdat)
   }
+
+  /// Build a named global of the given type.
+  ///
+  /// - parameter name: The name of the newly inserted global value.
+  /// - parameter type: The type of the newly inserted global value.
+  /// - parameter addressSpace: The optional address space where the global
+  ///   variable resides.
+  ///
+  /// - returns: A value representing the newly inserted global variable.
+  public func addGlobal(_ name: String, type: IRType, addressSpace: Int? = nil) -> Global {
+    let val: LLVMValueRef
+    if let addressSpace = addressSpace {
+      val = LLVMAddGlobalInAddressSpace(llvm, type.asLLVM(), name, UInt32(addressSpace))
+    } else {
+      val = LLVMAddGlobal(llvm, type.asLLVM(), name)
+    }
+    return Global(llvm: val)
+  }
+
+  /// Build a named global of the given type.
+  ///
+  /// - parameter name: The name of the newly inserted global value.
+  /// - parameter initializer: The initial value for the global variable.
+  /// - parameter addressSpace: The optional address space where the global
+  ///   variable resides.
+  ///
+  /// - returns: A value representing the newly inserted global variable.
+  public func addGlobal(_ name: String, initializer: IRValue, addressSpace: Int? = nil) -> Global {
+    var global = addGlobal(name, type: initializer.type)
+    global.initializer = initializer
+    return global
+  }
+
+  /// Build a named global string consisting of an array of `i8` type filled in
+  /// with the nul terminated string value.
+  ///
+  /// - parameter name: The name of the newly inserted global string value.
+  /// - parameter value: The character contents of the newly inserted global.
+  ///
+  /// - returns: A value representing the newly inserted global string variable.
+  public func addGlobalString(name: String, value: String) -> Global {
+    let length = value.utf8.count
+
+    var global = addGlobal(name, type:
+      ArrayType(elementType: IntType.int8, count: length + 1))
+
+    global.alignment = 1
+    global.initializer = value
+
+    return global
+  }
+
+  /// Build a named alias to a global value or a constant expression.
+  ///
+  /// Aliases, unlike function or variables, don’t create any new data. They are
+  /// just a new symbol and metadata for an existing position.
+  ///
+  /// - parameter name: The name of the newly inserted alias.
+  /// - parameter aliasee: The value or constant to alias.
+  /// - parameter type: The type of the aliased value or expression.
+  ///
+  /// - returns: A value representing the newly created alias.
+  public func addAlias(name: String, to aliasee: IRGlobal, type: IRType) -> Alias {
+    return Alias(llvm: LLVMAddAlias(llvm, type.asLLVM(), aliasee.asLLVM(), name))
+  }
 }
 
 /// An `IRBuilder` is a helper object that generates LLVM instructions.  IR
@@ -1803,13 +1868,7 @@ public class IRBuilder {
   ///
   /// - returns: A value representing the newly inserted global variable.
   public func addGlobal(_ name: String, type: IRType, addressSpace: Int? = nil) -> Global {
-    let llvm: LLVMValueRef
-    if let addressSpace = addressSpace {
-      llvm = LLVMAddGlobalInAddressSpace(module.llvm, type.asLLVM(), name, UInt32(addressSpace))
-    } else {
-      llvm = LLVMAddGlobal(module.llvm, type.asLLVM(), name)
-    }
-    return Global(llvm: llvm)
+    return self.module.addGlobal(name, type: type, addressSpace: addressSpace)
   }
 
   /// Build a named global of the given type.
@@ -1821,9 +1880,7 @@ public class IRBuilder {
   ///
   /// - returns: A value representing the newly inserted global variable.
   public func addGlobal(_ name: String, initializer: IRValue, addressSpace: Int? = nil) -> Global {
-    var global = addGlobal(name, type: initializer.type)
-    global.initializer = initializer
-    return global
+    return self.module.addGlobal(name, initializer: initializer, addressSpace: addressSpace)
   }
 
   /// Build a named global string consisting of an array of `i8` type filled in
@@ -1834,15 +1891,7 @@ public class IRBuilder {
   ///
   /// - returns: A value representing the newly inserted global string variable.
   public func addGlobalString(name: String, value: String) -> Global {
-    let length = value.utf8.count
-
-    var global = addGlobal(name, type:
-      ArrayType(elementType: IntType.int8, count: length + 1))
-
-    global.alignment = 1
-    global.initializer = value
-
-    return global
+    return self.module.addGlobalString(name: name, value: value)
   }
 
   /// Build a named global variable containing the characters of the given
@@ -1880,7 +1929,7 @@ public class IRBuilder {
   ///
   /// - returns: A value representing the newly created alias.
   public func addAlias(name: String, to aliasee: IRGlobal, type: IRType) -> Alias {
-    return Alias(llvm: LLVMAddAlias(module.llvm, type.asLLVM(), aliasee.asLLVM(), name))
+    return self.module.addAlias(name: name, to: aliasee, type: type)
   }
 
   // MARK: Inline Assembly