Index: clang-tools-extra/clangd/xpc/framework/CMakeLists.txt
===================================================================
--- clang-tools-extra/clangd/xpc/framework/CMakeLists.txt
+++ clang-tools-extra/clangd/xpc/framework/CMakeLists.txt
@@ -1,6 +1,7 @@
 
 set(SOURCES
-    ClangdXPC.cpp)
+  ClangdXPC.cpp
+)
 add_clang_library(ClangdXPCLib SHARED
   ${SOURCES}
   DEPENDS
Index: clang-tools-extra/clangd/xpc/test-client/ClangdXPCTestClient.cpp
===================================================================
--- clang-tools-extra/clangd/xpc/test-client/ClangdXPCTestClient.cpp
+++ clang-tools-extra/clangd/xpc/test-client/ClangdXPCTestClient.cpp
@@ -49,8 +49,10 @@
   // Open the ClangdXPC dylib in the framework.
   std::string LibPath = getLibraryPath();
   void *dlHandle = dlopen(LibPath.c_str(), RTLD_LOCAL | RTLD_FIRST);
-  if (!dlHandle)
+  if (!dlHandle) {
+    llvm::errs() << "Failed to load framework from \'" << LibPath << "\'\n";
     return 1;
+  }
 
   // Lookup the XPC service bundle name, and launch it.
   clangd_xpc_get_bundle_identifier_t clangd_xpc_get_bundle_identifier =
Index: llvm/utils/gn/build/symlink_or_copy.py
===================================================================
--- llvm/utils/gn/build/symlink_or_copy.py
+++ llvm/utils/gn/build/symlink_or_copy.py
@@ -22,6 +22,11 @@
     # FIXME: This should not check the host platform but the target platform
     # (which needs to be passed in as an arg), for cross builds.
     if sys.platform != 'win32':
+        try:
+            os.makedirs(os.path.dirname(args.output))
+        except OSError as e:
+            if e.errno != errno.EEXIST:
+                raise
         try:
             os.symlink(args.source, args.output)
         except OSError as e:
Index: llvm/utils/gn/build/toolchain/BUILD.gn
===================================================================
--- llvm/utils/gn/build/toolchain/BUILD.gn
+++ llvm/utils/gn/build/toolchain/BUILD.gn
@@ -113,11 +113,27 @@
       default_output_dir = "{{root_out_dir}}/bin"
     }
 
+    copy_command = "ln -f {{source}} {{output}} 2>/dev/null || (rm -rf {{output}} && cp -af {{source}} {{output}})"
     tool("copy") {
-      command = "ln -f {{source}} {{output}} 2>/dev/null || (rm -rf {{output}} && cp -af {{source}} {{output}})"
+      command = copy_command
       description = "COPY {{source}} {{output}}"
     }
 
+    if (current_os == "mac") {
+      tool("copy_bundle_data") {
+        # http://serverfault.com/q/209888/43689
+        _copydir = "mkdir -p {{output}} && cd {{source}} && " +
+                   "pax -rwl . \"\$OLDPWD\"/{{output}}"
+        command = "rm -rf {{output}} && if [[ -d {{source}} ]]; then " +
+                  _copydir + "; else " + copy_command + "; fi"
+        description = "COPY_BUNDLE_DATA {{source}} {{output}}"
+      }
+      tool("compile_xcassets") {
+        command = "false"
+        description = "The LLVM build doesn't use any xcasset files"
+      }
+    }
+
     tool("stamp") {
       command = "touch {{output}}"
       description = "STAMP {{output}}"
Index: llvm/utils/gn/secondary/clang-tools-extra/clangd/xpc/framework/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/clang-tools-extra/clangd/xpc/framework/BUILD.gn
@@ -0,0 +1,154 @@
+import("//llvm/utils/gn/build/symlink_or_copy.gni")
+import("//llvm/utils/gn/build/write_cmake_config.gni")
+
+# create_clangd_xpc_framework() in cmake creates both the ClangdXPC.framework
+# bundle and the clangd.xpc bundle within it in a single action.
+# Since GN has some native support for macOS bundles, it's more natural
+# to have one create_bundle() each for both ClangdXPC.framework and clangd.xpc.
+# See `llvm/utils/gn/gn.py help create_bundle` and ../cmake/modules.
+
+######################################################################
+# clangd.xpc bundle
+
+write_cmake_config("XPCServiceInfo.plist") {
+  input = "../cmake/XPCServiceInfo.plist.in"
+  output = "$target_gen_dir/XPCServiceInfo.plist"
+  service_name = "clangd"
+  values = [
+    "CLANGD_XPC_SERVICE_NAME=$service_name",
+    "CLANGD_XPC_SERVICE_BUNDLE_NAME=org.llvm.$service_name",
+  ]
+}
+
+bundle_data("clangxpc_bundle_xpc_service_info_plist") {
+  public_deps = [
+    ":XPCServiceInfo.plist",
+  ]
+  sources = [
+    "$target_gen_dir/XPCServiceInfo.plist",
+  ]
+  outputs = [
+    "{{bundle_contents_dir}}/Info.plist",
+  ]
+}
+
+bundle_data("clangxpc_bundle_xpc_service_executable") {
+  public_deps = [
+    "//clang-tools-extra/clangd/tool:clangd",
+  ]
+  sources = [
+    "$root_out_dir/bin/clangd",
+  ]
+  outputs = [
+    "{{bundle_executable_dir}}/clangd",
+  ]
+}
+
+create_bundle("clangd.xpc") {
+  # .app directory structure.
+  # Since this target only exists to be copied into ClangdXPC.framework,
+  # put it in $target_gen_dir, not $root_out_dir.
+  bundle_root_dir = "$target_gen_dir/$target_name"
+  bundle_contents_dir = "$bundle_root_dir/Contents"
+  bundle_executable_dir = "$bundle_contents_dir/MacOS"
+
+  deps = [
+    ":clangxpc_bundle_xpc_service_executable",
+    ":clangxpc_bundle_xpc_service_info_plist",
+  ]
+}
+
+######################################################################
+# ClangdXPC.framework
+
+write_cmake_config("Info.plist") {
+  input = "../cmake/Info.plist.in"
+  output = "$target_gen_dir/Info.plist"
+  values = [ "CLANGD_XPC_FRAMEWORK_NAME=ClangdXPC" ]
+}
+
+bundle_data("clangdxpc_bundle_info_plist") {
+  public_deps = [
+    ":Info.plist",
+  ]
+  sources = [
+    "$target_gen_dir/Info.plist",
+  ]
+  outputs = [
+    "{{bundle_resources_dir}}/Info.plist",
+  ]
+}
+
+shared_library("ClangdXPCLib") {
+  deps = [
+    "//clang-tools-extra/clangd/tool:clangd",
+  ]
+  sources = [
+    "ClangdXPC.cpp",
+  ]
+}
+
+bundle_data("clangdxpc_bundle_executable") {
+  public_deps = [
+    ":ClangdXPCLib",
+  ]
+  sources = [
+    "$root_out_dir/lib/libClangdXPCLib.dylib",
+  ]
+  outputs = [
+    "{{bundle_executable_dir}}/ClangdXPC",
+  ]
+}
+
+bundle_data("clangdxpc_bundle_xpc") {
+  public_deps = [
+    ":clangd.xpc",
+  ]
+  sources = [
+    "$target_gen_dir/clangd.xpc",
+  ]
+  outputs = [
+    "{{bundle_contents_dir}}/XPCServices/clangd.xpc",
+  ]
+}
+
+# .framework bundle symlinks:
+# - ./ClangdXPC -> Versions/Current/ClangdXPC
+# - ./Resources -> Versions/Current/Resources
+# - ./XPCServices -> Versions/Current/XPCServices
+# - ./Versions/Current -> Versions/A
+# Since bundles are a mac thing, we know that symlink_or_copy() will symlink
+# and not copy, and hence creating the symlink before the target exists is safe.
+symlinks = [
+  "ClangdXPC",
+  "Resources",
+  "XPCServices",
+]
+foreach(target, symlinks) {
+  symlink_or_copy("clangdxpc_symlink_$target") {
+    source = "Versions/Current/$target"
+    output = "$root_out_dir/lib/ClangdXPC.framework/$target"
+  }
+}
+symlink_or_copy("clangdxpc_symlink_Versions_Current") {
+  source = "A"
+  output = "$root_out_dir/lib/ClangdXPC.framework/Versions/Current"
+}
+
+create_bundle("ClangdXPC.framework") {
+  # .framework directory structure.
+  bundle_root_dir = "$root_out_dir/lib/$target_name"
+  bundle_contents_dir = "$bundle_root_dir/Versions/A"
+  bundle_executable_dir = "$bundle_contents_dir"
+  bundle_resources_dir = "$bundle_contents_dir/Resources"
+
+  deps = [
+    ":clangdxpc_bundle_executable",
+    ":clangdxpc_bundle_info_plist",
+    ":clangdxpc_bundle_xpc",
+    ":clangdxpc_symlink_Versions_Current",
+  ]
+  foreach(target, symlinks) {
+    deps += [ ":clangdxpc_symlink_$target" ]
+  }
+}
Index: llvm/utils/gn/secondary/clang-tools-extra/clangd/xpc/test-client/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/clang-tools-extra/clangd/xpc/test-client/BUILD.gn
@@ -0,0 +1,20 @@
+executable("clangd-xpc-test-client") {
+  configs += [ "//llvm/utils/gn/build:clang_code" ]
+  deps = [
+    "//clang-tools-extra/clangd",
+    "//clang-tools-extra/clangd/xpc:conversions",
+    "//clang-tools-extra/clangd/xpc/framework:ClangdXPC.framework",
+    "//clang/lib/Basic",
+    "//clang/lib/Format",
+    "//clang/lib/Frontend",
+    "//clang/lib/Sema",
+    "//clang/lib/Tooling",
+    "//clang/lib/Tooling/Core",
+    "//llvm/lib/Support",
+  ]
+
+  include_dirs = [ "../.." ]
+  sources = [
+    "ClangdXPCTestClient.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/clang-tools-extra/test/BUILD.gn
===================================================================
--- llvm/utils/gn/secondary/clang-tools-extra/test/BUILD.gn
+++ llvm/utils/gn/secondary/clang-tools-extra/test/BUILD.gn
@@ -1,3 +1,4 @@
+import("//clang-tools-extra/clangd/xpc/enable.gni")
 import("//clang/lib/StaticAnalyzer/Frontend/enable.gni")
 import("//llvm/triples.gni")
 import("//llvm/utils/gn/build/write_cmake_config.gni")
@@ -35,9 +36,14 @@
     "LLVM_LIT_TOOLS_DIR=",  # Intentionally empty, matches cmake build.
     "LLVM_TOOLS_DIR=" + rebase_path("$root_out_dir/bin"),
     "PYTHON_EXECUTABLE=$python_path",
-    "CLANGD_BUILD_XPC_SUPPORT=0",  # FIXME
   ]
 
+  if (clangd_build_xpc) {
+    extra_values += [ "CLANGD_BUILD_XPC_SUPPORT=1" ]
+  } else {
+    extra_values += [ "CLANGD_BUILD_XPC_SUPPORT=0" ]
+  }
+
   if (clang_enable_static_analyzer) {
     extra_values += [ "CLANG_ENABLE_STATIC_ANALYZER=1" ]
   } else {
@@ -83,6 +89,10 @@
     "//llvm/utils/llvm-lit",
     "//llvm/utils/not",
   ]
+  if (clangd_build_xpc) {
+    deps +=
+        [ "//clang-tools-extra/clangd/xpc/test-client:clangd-xpc-test-client" ]
+  }
 
   # FIXME: dep on dexp once it exist
   testonly = true