gn build: Add build files for clangd xpc framework code

This is a bit of a larger change since this is the first (and as far as
I can tell only) place where the LLVM build produces macOS framework
bundles.

GN has some built-in support for this, so use that.
`gn help create_bundle` has a terse description (but it's a bit
outdated: `deps` must be `public_deps` and the conditionals in the
example in the help aren't quite right on non-iOS).

We need a new 'copy_bundle_data' tool, and since we copy the clangd.xpc
bundle as bundle_data into ClangdXPC.framework it needs to be able to
handle directories in addition to files.

GN also insists we have a compile_xcassets tool even though it's not
used. I just made that run `false`.

Despite GN's support for bundles, we still need to manually create the
expected symlink structure in the .framework bundle. Since this code
never runs on Windows, it's safe to create the symlinks before the
symlink targets exist, so we can just make the bundle depend on the
steps that create the symlinks. For this to work, change the symlink
script to create the symlink's containing directory if it doesn't yet
exist.

I locally verified that CMake and GN build create the same bundle
structure. (I noticed that both builds set LC_ID_DYLIB to the pre-copy
libClangdXPCLib.dylib name, but that seems to not cause any issues and
it happens in the CMake build too.)

(Also add an error message to clangd-xpc-test-client for when loading
the dylib fails – this was useful while locally debugging this.)

Differential Revision: https://reviews.llvm.org/D60130

llvm-svn: 357574

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

clang-tools-extra/clangd/xpc/test-client/ClangdXPCTestClient.cpp

@@ -49,8 +49,10 @@ int main(int argc, char *argv[]) {
   // 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 =

llvm/utils/gn/build/symlink_or_copy.py

@@ -22,6 +22,11 @@ def main():
     # 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:

llvm/utils/gn/build/toolchain/BUILD.gn

@@ -113,11 +113,27 @@ template("unix_toolchain") {
       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}}"

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}}/{{source_file_part}}",
+  ]
+}
+
+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 = [
+    "$target_gen_dir/Info.plist",
+  ]
+  outputs = [
+    "{{bundle_resources_dir}}/{{source_file_part}}",
+  ]
+}
+
+shared_library("ClangdXPCLib") {
+  deps = [
+    "//clang-tools-extra/clangd/tool:clangd",
+  ]
+  sources = [
+    "ClangdXPC.cpp",
+  ]
+}
+
+bundle_data("clangdxpc_bundle_executable") {
+  public_deps = [
+    ":ClangdXPCLib",
+  ]
+  sources = [
+    "$root_out_dir/lib/libClangdXPCLib.dylib",
+  ]
+  outputs = [
+    "{{bundle_executable_dir}}/ClangdXPC",
+  ]
+}
+
+bundle_data("clangdxpc_bundle_xpc") {
+  public_deps = [
+    ":clangd.xpc",
+  ]
+  sources = [
+    "$target_gen_dir/clangd.xpc",
+  ]
+  outputs = [
+    "{{bundle_contents_dir}}/XPCServices/{{source_file_part}}",
+  ]
+}
+
+# .framework bundle symlinks:
+# - ./ClangdXPC -> Versions/Current/ClangdXPC
+# - ./Resources -> Versions/Current/Resources
+# - ./XPCServices -> Versions/Current/XPCServices
+# - ./Versions/Current -> Versions/A
+# Since bundles are a mac thing, we know that symlink_or_copy() will symlink
+# and not copy, and hence creating the symlink before the target exists is safe.
+symlinks = [
+  "ClangdXPC",
+  "Resources",
+  "XPCServices",
+]
+foreach(target, symlinks) {
+  symlink_or_copy("clangdxpc_symlink_$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" ]
+  }
+}

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",
+  ]
+}

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 @@ write_lit_config("lit_site_cfg") {
     "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 @@ group("test") {
     "//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