1 files changed, 74 insertions, 0 deletions
diff --git a/include/llvm/LTO/LTO.h b/include/llvm/LTO/LTO.h
new file mode 100644
index 0000000000000..5154c0007aaa5
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+++ b/include/llvm/LTO/LTO.h
@@ -0,0 +1,74 @@
+//===-LTO.h - LLVM Link Time Optimizer ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares functions and classes used to support LTO. It is intended
+// to be used both by LTO classes as well as by clients (gold-plugin) that
+// don't utilize the LTO code generator interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LTO_LTO_H
+#define LLVM_LTO_LTO_H
+
+#include "llvm/ADT/StringMap.h"
+#include "llvm/IR/ModuleSummaryIndex.h"
+
+namespace llvm {
+
+class LLVMContext;
+class MemoryBufferRef;
+class Module;
+
+/// Helper to load a module from bitcode.
+std::unique_ptr<Module> loadModuleFromBuffer(const MemoryBufferRef &Buffer,
+                                             LLVMContext &Context, bool Lazy);
+
+/// Provide a "loader" for the FunctionImporter to access function from other
+/// modules.
+class ModuleLoader {
+  /// The context that will be used for importing.
+  LLVMContext &Context;
+
+  /// Map from Module identifier to MemoryBuffer. Used by clients like the
+  /// FunctionImported to request loading a Module.
+  StringMap<MemoryBufferRef> &ModuleMap;
+
+public:
+  ModuleLoader(LLVMContext &Context, StringMap<MemoryBufferRef> &ModuleMap)
+      : Context(Context), ModuleMap(ModuleMap) {}
+
+  /// Load a module on demand.
+  std::unique_ptr<Module> operator()(StringRef Identifier) {
+    return loadModuleFromBuffer(ModuleMap[Identifier], Context, /*Lazy*/ true);
+  }
+};
+
+
+/// Resolve Weak and LinkOnce values in the \p Index. Linkage changes recorded
+/// in the index and the ThinLTO backends must apply the changes to the Module
+/// via thinLTOResolveWeakForLinkerModule.
+///
+/// This is done for correctness (if value exported, ensure we always
+/// emit a copy), and compile-time optimization (allow drop of duplicates).
+void thinLTOResolveWeakForLinkerInIndex(
+    ModuleSummaryIndex &Index,
+    function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
+        isPrevailing,
+    function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
+        recordNewLinkage);
+
+/// Update the linkages in the given \p Index to mark exported values
+/// as external and non-exported values as internal. The ThinLTO backends
+/// must apply the changes to the Module via thinLTOInternalizeModule.
+void thinLTOInternalizeAndPromoteInIndex(
+    ModuleSummaryIndex &Index,
+    function_ref<bool(StringRef, GlobalValue::GUID)> isExported);
+}
+
+#endif