3 files changed, 133 insertions, 0 deletions
diff --git a/llvm/include/llvm/Demangle/Compiler.h b/llvm/include/llvm/Demangle/Compiler.h
index c996f9b71e5..da1e2715f2a 100644
--- a/llvm/include/llvm/Demangle/Compiler.h
+++ b/llvm/include/llvm/Demangle/Compiler.h
@@ -503,4 +503,22 @@ void AnnotateIgnoreWritesEnd(const char *file, int line);
 #define LLVM_ENABLE_EXCEPTIONS 1
 #endif
 
+/// \macro LLVM_PLUGIN_IMPORT
+/// \brief Used to import the well-known entry point for registering loaded pass
+/// plugins
+#ifdef WIN32
+#define LLVM_PLUGIN_IMPORT __declspec(dllimport)
+#else
+#define LLVM_PLUGIN_IMPORT
+#endif
+
+/// \macro LLVM_PLUGIN_EXPORT
+/// \brief Used to export the well-known entry point for registering loaded pass
+/// plugins
+#ifdef WIN32
+#define LLVM_PLUGIN_EXPORT __declspec(dllexport)
+#else
+#define LLVM_PLUGIN_EXPORT
+#endif
+
 #endif
diff --git a/llvm/include/llvm/Passes/PassPlugin.h b/llvm/include/llvm/Passes/PassPlugin.h
new file mode 100644
index 00000000000..c61a1974630
--- /dev/null
+++ b/llvm/include/llvm/Passes/PassPlugin.h
@@ -0,0 +1,114 @@
+//===- llvm/Passes/PassPlugin.h - Public Plugin API -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines the public entry point for new-PM pass plugins.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PASSES_PASSPLUGIN_H
+#define LLVM_PASSES_PASSPLUGIN_H
+
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/Support/Error.h"
+#include <cstdint>
+#include <string>
+
+namespace llvm {
+class PassBuilder;
+
+/// \macro LLVM_PLUGIN_API_VERSION
+/// Identifies the API version understood by this plugin.
+///
+/// When a plugin is loaded, the driver will check it's supported plugin version
+/// against that of the plugin. A mismatch is an error. The supported version
+/// will be incremented for ABI-breaking changes to the \c PassPluginLibraryInfo
+/// struct, i.e. when callbacks are added, removed, or reordered.
+#define LLVM_PLUGIN_API_VERSION 1
+
+extern "C" {
+/// Information about the plugin required to load its passes
+///
+/// This struct defines the core interface for pass plugins and is supposed to
+/// be filled out by plugin implementors. LLVM-side users of a plugin are
+/// expected to use the \c PassPlugin class below to interface with it.
+struct PassPluginLibraryInfo {
+  /// The API version understood by this plugin, usually \c
+  /// LLVM_PLUGIN_API_VERSION
+  uint32_t APIVersion;
+  /// A meaningful name of the plugin.
+  const char *PluginName;
+  /// The version of the plugin.
+  const char *PluginVersion;
+
+  /// The callback for registering plugin passes with a \c PassBuilder
+  /// instance
+  void (*RegisterPassBuilderCallbacks)(PassBuilder &);
+};
+}
+
+/// A loaded pass plugin.
+///
+/// An instance of this class wraps a loaded pass plugin and gives access to
+/// its interface defined by the \c PassPluginLibraryInfo it exposes.
+class PassPlugin {
+public:
+  /// Attempts to load a pass plugin from a given file.
+  ///
+  /// \returns Returns an error if either the library cannot be found or loaded,
+  /// there is no public entry point, or the plugin implements the wrong API
+  /// version.
+  static Expected<PassPlugin> Load(const std::string &Filename);
+
+  /// Get the filename of the loaded plugin.
+  StringRef getFilename() const { return Filename; }
+
+  /// Get the plugin name
+  StringRef getPluginName() const { return Info.PluginName; }
+
+  /// Get the plugin version
+  StringRef getPluginVersion() const { return Info.PluginVersion; }
+
+  /// Get the plugin API version
+  uint32_t getAPIVersion() const { return Info.APIVersion; }
+
+  /// Invoke the PassBuilder callback registration
+  void registerPassBuilderCallbacks(PassBuilder &PB) const {
+    Info.RegisterPassBuilderCallbacks(PB);
+  }
+
+private:
+  PassPlugin(const std::string &Filename, const sys::DynamicLibrary &Library)
+      : Filename(Filename), Library(Library), Info() {}
+
+  std::string Filename;
+  sys::DynamicLibrary Library;
+  PassPluginLibraryInfo Info;
+};
+}
+
+/// The public entry point for a pass plugin.
+///
+/// When a plugin is loaded by the driver, it will call this entry point to
+/// obtain information about this plugin and about how to register its passes.
+/// This function needs to be implemented by the plugin, see the example below:
+///
+/// ```
+/// extern "C" ::llvm::PassPluginLibraryInfo LLVM_ATTRIBUTE_WEAK
+/// LLVM_PLUGIN_EXPORT llvmGetPassPluginInfo() {
+///   return {
+///     LLVM_PLUGIN_API_VERSION, "MyPlugin", "v0.1", [](PassBuilder &PB) { ... }
+///   };
+/// }
+/// ```
+extern "C" ::llvm::PassPluginLibraryInfo LLVM_ATTRIBUTE_WEAK LLVM_PLUGIN_IMPORT
+llvmGetPassPluginInfo();
+
+#endif /* LLVM_PASSES_PASSPLUGIN_H */
diff --git a/llvm/include/llvm/Support/Compiler.h b/llvm/include/llvm/Support/Compiler.h
index 43a96e49ce9..c42a70b310d 100644
--- a/llvm/include/llvm/Support/Compiler.h
+++ b/llvm/include/llvm/Support/Compiler.h
@@ -16,4 +16,5 @@
 //
 //===----------------------------------------------------------------------===//
 
+
 #include "llvm/Demangle/Compiler.h"