From cb66e61dd01b0c6094e1874cdcc9328600c8251b Mon Sep 17 00:00:00 2001
From: Robert Widmann <devteam.codafi@gmail.com>
Date: Fri, 13 Jan 2017 22:16:18 -0700
Subject: [PATCH] Add Alias emission to the builder
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Aliases are completely useless at the moment as there aren’t wrappers
for its accessors.
---
 Sources/LLVM/Alias.swift     | 12 ++++++++++++
 Sources/LLVM/IRBuilder.swift | 14 ++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 Sources/LLVM/Alias.swift

diff --git a/Sources/LLVM/Alias.swift b/Sources/LLVM/Alias.swift
new file mode 100644
index 00000000..9bd23d14
--- /dev/null
+++ b/Sources/LLVM/Alias.swift
@@ -0,0 +1,12 @@
+import cllvm
+
+/// An `Alias` represents a global alias in an LLVM module - a new symbol and 
+/// corresponding metadata for an existing position
+public struct Alias: IRValue {
+  internal let llvm: LLVMValueRef
+
+  /// Retrieves the underlying LLVM value object.
+  public func asLLVM() -> LLVMValueRef {
+    return llvm
+  }
+}
diff --git a/Sources/LLVM/IRBuilder.swift b/Sources/LLVM/IRBuilder.swift
index f475befc..da556597 100644
--- a/Sources/LLVM/IRBuilder.swift
+++ b/Sources/LLVM/IRBuilder.swift
@@ -1335,6 +1335,20 @@ public class IRBuilder {
   public func buildGlobalStringPtr(_ string: String, name: String = "") -> IRValue {
     return LLVMBuildGlobalStringPtr(llvm, string, name)
   }
+
+  /// Builds 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: IRValue, type: IRType) -> Alias {
+    return Alias(llvm: LLVMAddAlias(module.llvm, type.asLLVM(), aliasee.asLLVM(), name))
+  }
   
   deinit {
     LLVMDisposeBuilder(llvm)