[SourceKit] Add mechanism to load plugins for request handling into SourceKit

include/swift/Basic/LoadDynamicLibrary.h

@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_BASIC_LOADDYNAMICLIBRARY_H
+#define SWIFT_BASIC_LOADDYNAMICLIBRARY_H
+
+#include <string>
+
+namespace swift {
+void *loadLibrary(const char *path, std::string *err);
+void *getAddressOfSymbol(void *handle, const char *symbol);
+} // end namespace swift
+
+#endif // SWIFT_BASIC_LOADDYNAMICLIBRARY_H

lib/AST/PluginRegistry.cpp

@@ -14,6 +14,7 @@
 
 #include "swift/Basic/Assertions.h"
 #include "swift/Basic/Defer.h"
+#include "swift/Basic/LoadDynamicLibrary.h"
 #include "swift/Basic/LLVM.h"
 #include "swift/Basic/Program.h"
 #include "swift/Basic/Sandbox.h"
@@ -25,16 +26,6 @@
 
 #include <signal.h>
 
-#if defined(_WIN32)
-#define WIN32_LEAN_AND_MEAN
-#define NOMINMAX
-#include "llvm/Support/ConvertUTF.h"
-#include "llvm/Support/Windows/WindowsSupport.h"
-#include <windows.h>
-#else
-#include <dlfcn.h>
-#endif
-
 #if HAVE_UNISTD_H
 #include <unistd.h>
 #elif defined(_WIN32)
@@ -43,46 +34,6 @@
 
 using namespace swift;
 
-namespace {
-void *loadLibrary(const char *path, std::string *err);
-void *getAddressOfSymbol(void *handle, const char *symbol);
-
-#if defined(_WIN32)
-void *loadLibrary(const char *path, std::string *err) {
-  SmallVector<wchar_t, MAX_PATH> pathUnicode;
-  if (std::error_code ec = llvm::sys::windows::UTF8ToUTF16(path, pathUnicode)) {
-    SetLastError(ec.value());
-    llvm::MakeErrMsg(err, std::string(path) + ": Can't convert to UTF-16");
-    return nullptr;
-  }
-
-  HMODULE handle = LoadLibraryW(pathUnicode.data());
-  if (handle == NULL) {
-    llvm::MakeErrMsg(err, std::string(path) + ": Can't open");
-    return nullptr;
-  }
-  return (void *)handle;
-}
-
-void *getAddressOfSymbol(void *handle, const char *symbol) {
-  return (void *)uintptr_t(GetProcAddress((HMODULE)handle, symbol));
-}
-
-#else
-void *loadLibrary(const char *path, std::string *err) {
-  void *handle = ::dlopen(path, RTLD_LAZY | RTLD_LOCAL);
-  if (!handle)
-    *err = ::dlerror();
-  return handle;
-}
-
-void *getAddressOfSymbol(void *handle, const char *symbol) {
-  return ::dlsym(handle, symbol);
-}
-
-#endif
-} // namespace
-
 PluginRegistry::PluginRegistry() {
   dumpMessaging = ::getenv("SWIFT_DUMP_PLUGIN_MESSAGING") != nullptr;
 }

lib/Basic/CMakeLists.txt

@@ -58,6 +58,7 @@ add_swift_host_library(swiftBasic STATIC
   ParseableOutput.cpp
   JSONSerialization.cpp
   LangOptions.cpp
+  LoadDynamicLibrary.cpp
   Located.cpp
   Mangler.cpp
   OutputFileMap.cpp

lib/Basic/LoadDynamicLibrary.cpp

@@ -0,0 +1,58 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/Basic/LoadDynamicLibrary.h"
+
+#if defined(_WIN32)
+#define WIN32_LEAN_AND_MEAN
+#define NOMINMAX
+#include "llvm/Support/ConvertUTF.h"
+#include "llvm/Support/Windows/WindowsSupport.h"
+#include "swift/Basic/LLVM.h"
+#include <windows.h>
+#else
+#include <dlfcn.h>
+#endif
+
+#if defined(_WIN32)
+void *swift::loadLibrary(const char *path, std::string *err) {
+  SmallVector<wchar_t, MAX_PATH> pathUnicode;
+  if (std::error_code ec = llvm::sys::windows::UTF8ToUTF16(path, pathUnicode)) {
+    SetLastError(ec.value());
+    llvm::MakeErrMsg(err, std::string(path) + ": Can't convert to UTF-16");
+    return nullptr;
+  }
+
+  HMODULE handle = LoadLibraryW(pathUnicode.data());
+  if (handle == NULL) {
+    llvm::MakeErrMsg(err, std::string(path) + ": Can't open");
+    return nullptr;
+  }
+  return (void *)handle;
+}
+
+void *swift::getAddressOfSymbol(void *handle, const char *symbol) {
+  return (void *)uintptr_t(GetProcAddress((HMODULE)handle, symbol));
+}
+
+#else
+void *swift::loadLibrary(const char *path, std::string *err) {
+  void *handle = ::dlopen(path, RTLD_LAZY | RTLD_LOCAL);
+  if (!handle)
+    *err = ::dlerror();
+  return handle;
+}
+
+void *swift::getAddressOfSymbol(void *handle, const char *symbol) {
+  return ::dlsym(handle, symbol);
+}
+#endif

tools/SourceKit/include/SourceKit/Core/Context.h

@@ -31,28 +31,30 @@ namespace llvm {
 namespace SourceKit {
   class LangSupport;
   class NotificationCenter;
-
-class GlobalConfig {
-public:
-  struct Settings {
-    struct IDEInspectionOptions {
-
-      /// Max count of reusing ASTContext for cached IDE inspection.
-      unsigned MaxASTContextReuseCount = 100;
-
-      /// Interval second for checking dependencies in cached IDE inspection.
-      unsigned CheckDependencyInterval = 5;
-    } IDEInspectionOpts;
-  };
-
-private:
-  Settings State;
-  mutable llvm::sys::Mutex Mtx;
-
-public:
-  Settings update(std::optional<unsigned> IDEInspectionMaxASTContextReuseCount,
-                  std::optional<unsigned> IDEInspectionCheckDependencyInterval);
-  Settings::IDEInspectionOptions getIDEInspectionOpts() const;
+  class PluginSupport;
+
+  class GlobalConfig {
+  public:
+    struct Settings {
+      struct IDEInspectionOptions {
+
+        /// Max count of reusing ASTContext for cached IDE inspection.
+        unsigned MaxASTContextReuseCount = 100;
+
+        /// Interval second for checking dependencies in cached IDE inspection.
+        unsigned CheckDependencyInterval = 5;
+      } IDEInspectionOpts;
+    };
+
+  private:
+    Settings State;
+    mutable llvm::sys::Mutex Mtx;
+
+  public:
+    Settings
+    update(std::optional<unsigned> IDEInspectionMaxASTContextReuseCount,
+           std::optional<unsigned> IDEInspectionCheckDependencyInterval);
+    Settings::IDEInspectionOptions getIDEInspectionOpts() const;
 };
 
 /// Keeps track of all requests that are currently in progress and coordinates
@@ -169,13 +171,16 @@ class Context {
   std::shared_ptr<NotificationCenter> NotificationCtr;
   std::shared_ptr<GlobalConfig> Config;
   std::shared_ptr<RequestTracker> ReqTracker;
+  std::shared_ptr<PluginSupport> Plugins;
   std::shared_ptr<SlowRequestSimulator> SlowRequestSim;
 
 public:
   Context(StringRef SwiftExecutablePath, StringRef RuntimeLibPath,
           StringRef DiagnosticDocumentationPath,
           llvm::function_ref<std::unique_ptr<LangSupport>(Context &)>
               LangSupportFactoryFn,
+          llvm::function_ref<std::shared_ptr<PluginSupport>(Context &)>
+              PluginSupportFactoryFn,
           bool shouldDispatchNotificationsOnMain = true);
   ~Context();
 
@@ -192,6 +197,8 @@ class Context {
 
   std::shared_ptr<GlobalConfig> getGlobalConfiguration() { return Config; }
 
+  std::shared_ptr<PluginSupport> getPlugins() { return Plugins; }
+
   std::shared_ptr<SlowRequestSimulator> getSlowRequestSimulator() {
     return SlowRequestSim;
   }

tools/SourceKit/include/SourceKit/Core/LangSupport.h

@@ -1024,6 +1024,8 @@ class LangSupport {
 
   virtual ~LangSupport() { }
 
+  virtual void *getOpaqueSwiftIDEInspectionInstance() { return nullptr; }
+
   virtual void globalConfigurationUpdated(std::shared_ptr<GlobalConfig> Config) {};
 
   virtual void dependencyUpdated() {}

tools/SourceKit/lib/Core/Context.cpp

@@ -40,6 +40,8 @@ SourceKit::Context::Context(
     StringRef DiagnosticDocumentationPath,
     llvm::function_ref<std::unique_ptr<LangSupport>(Context &)>
         LangSupportFactoryFn,
+    llvm::function_ref<std::shared_ptr<PluginSupport>(Context &)>
+        PluginSupportFactoryFn,
     bool shouldDispatchNotificationsOnMain)
     : SwiftExecutablePath(SwiftExecutablePath), RuntimeLibPath(RuntimeLibPath),
       DiagnosticDocumentationPath(DiagnosticDocumentationPath),
@@ -49,6 +51,7 @@ SourceKit::Context::Context(
       SlowRequestSim(new SlowRequestSimulator(ReqTracker)) {
   // Should be called last after everything is initialized.
   SwiftLang = LangSupportFactoryFn(*this);
+  Plugins = PluginSupportFactoryFn(*this);
 }
 
 SourceKit::Context::~Context() {

tools/SourceKit/lib/SwiftLang/SwiftLangSupport.h

@@ -534,6 +534,10 @@ class SwiftLangSupport : public LangSupport {
   // LangSupport Interface
   //==========================================================================//
 
+  void *getOpaqueSwiftIDEInspectionInstance() override {
+    return IDEInspectionInst.get();
+  }
+
   void globalConfigurationUpdated(std::shared_ptr<GlobalConfig> Config) override;
 
   void dependencyUpdated() override;

tools/SourceKit/tools/sourcekitd/bin/InProc/CMakeLists.txt

@@ -11,13 +11,16 @@ swift_is_installing_component(sourcekit-inproc SOURCEKIT_INSTALLING_INPROC)
 
 set(sourcekitdInProc_args
   sourcekitdInProc.cpp
+  CodeCompletionSwiftInterop.cpp
   LLVM_LINK_COMPONENTS support coverage
 )
 
 if (SOURCEKIT_INSTALLING_INPROC)
   if("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
     add_sourcekit_framework(sourcekitdInProc
       ${SOURCEKITD_SOURCE_DIR}/include/sourcekitd/sourcekitd.h
+      ${SOURCEKITD_SOURCE_DIR}/include/sourcekitd/plugin.h
+      ${CMAKE_CURRENT_SOURCE_DIR}/CodeCompletionSwiftInterop.h
       ${sourcekitdInProc_args}
       MODULEMAP module.modulemap
       INSTALL_IN_COMPONENT sourcekit-inproc