2 files changed, 51 insertions, 0 deletions
diff --git a/llvm/lib/Passes/CMakeLists.txt b/llvm/lib/Passes/CMakeLists.txt
index 8fcadcf2c95..cc39dfb798e 100644
--- a/llvm/lib/Passes/CMakeLists.txt
+++ b/llvm/lib/Passes/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_llvm_library(LLVMPasses
   PassBuilder.cpp
+  PassPlugin.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/Passes
diff --git a/llvm/lib/Passes/PassPlugin.cpp b/llvm/lib/Passes/PassPlugin.cpp
new file mode 100644
index 00000000000..8f689ee505c
--- /dev/null
+++ b/llvm/lib/Passes/PassPlugin.cpp
@@ -0,0 +1,50 @@
+//===- lib/Passes/PassPluginLoader.cpp - Load Plugins for New PM Passes ---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Passes/PassPlugin.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+Expected<PassPlugin> PassPlugin::Load(const std::string &Filename) {
+  std::string Error;
+  auto Library =
+      sys::DynamicLibrary::getPermanentLibrary(Filename.c_str(), &Error);
+  if (!Library.isValid())
+    return make_error<StringError>(Twine("Could not load library '") +
+                                       Filename + "': " + Error,
+                                   inconvertibleErrorCode());
+
+  PassPlugin P{Filename, Library};
+  auto *getDetailsFn =
+      Library.SearchForAddressOfSymbol("llvmGetPassPluginInfo");
+
+  if (!getDetailsFn)
+    // If the symbol isn't found, this is probably a legacy plugin, which is an
+    // error
+    return make_error<StringError>(Twine("Plugin entry point not found in '") +
+                                       Filename + "'. Is this a legacy plugin?",
+                                   inconvertibleErrorCode());
+
+  P.Info = reinterpret_cast<decltype(llvmGetPassPluginInfo) *>(getDetailsFn)();
+
+  if (P.Info.APIVersion != LLVM_PLUGIN_API_VERSION)
+    return make_error<StringError>(
+        Twine("Wrong API version on plugin '") + Filename + "'. Got version " +
+            Twine(P.Info.APIVersion) + ", supported version is " +
+            Twine(LLVM_PLUGIN_API_VERSION) + ".",
+        inconvertibleErrorCode());
+
+  if (!P.Info.RegisterPassBuilderCallbacks)
+    return make_error<StringError>(Twine("Empty entry callback in plugin '") +
+                                       Filename + "'.'",
+                                   inconvertibleErrorCode());
+
+  return P;
+}