[gn] Move Features.inc to clangd, create a config for it

[phosek]

Summary

ClangdLSPServer and clangd unittests now include Features.inc so we
need to append the target_gen_dir that contains it to their
include_dirs. To do so, we use a public config that's applied to
any target that depends on the features one.

[thakis]

Thanks!

[thakis]

Looks like this doesn't build:

[1/1] Regenerating ninja files
FAILED: build.ninja
../../llvm/utils/gn/bin/mac-amd64/gn --root=../.. -q --dotfile=../../llvm/utils/gn/.gn gen .
ERROR Unresolved dependencies.
//clang-tools-extra/clangd:clangd(//llvm/utils/gn/build/toolchain:unix)
  needs //clang-tools-extra/clangd/tool:features(//llvm/utils/gn/build/toolchain:unix)

[thakis]

llvm/trunk/utils/gn/secondary/clang-tools-extra/clangd/BUILD.gn

22 ↗

(On Diff #195983)

Ah, you didn't remove this line. Fixing; but please try your changes locally before landing :)

llvm/utils/gn/secondary/clang-tools-extra/clangd/BUILD.gn

+import("//clang-tools-extra/clangd/xpc/enable.gni")
+import("//llvm/utils/gn/build/write_cmake_config.gni")
+
+config("features_config") {
+  # To pick up the generated inc files.
+  include_dirs = [ target_gen_dir ]
+  visibility = [ ":features" ]
+}
+
+write_cmake_config("features") {
+  input = "Features.inc.in"
+  output = "$target_gen_dir/Features.inc"
+  values = []
+  if (clangd_build_xpc) {
+    values += [ "CLANGD_BUILD_XPC=1" ]
+  } else {
+    values += [ "CLANGD_BUILD_XPC=0" ]
+  }
+  public_configs = [ ":features_config" ]
+}
+
 static_library("clangd") {
   output_name = "clangDaemon"
   configs += [ "//llvm/utils/gn/build:clang_code" ]
   deps = [
+    ":features",
     "//clang-tools-extra/clang-tidy/abseil",
     "//clang-tools-extra/clang-tidy/android",
     "//clang-tools-extra/clang-tidy/boost",
     "//clang-tools-extra/clang-tidy/bugprone",
     "//clang-tools-extra/clang-tidy/cert",
     "//clang-tools-extra/clang-tidy/cppcoreguidelines",
     "//clang-tools-extra/clang-tidy/fuchsia",
     "//clang-tools-extra/clang-tidy/google",

llvm/utils/gn/secondary/clang-tools-extra/clangd/tool/BUILD.gn

 import("//clang-tools-extra/clangd/xpc/enable.gni")
-import("//llvm/utils/gn/build/write_cmake_config.gni")
-
-write_cmake_config("features") {
-  # FIXME: Try moving Features.inc.in to tools, seems like a better location.
-  input = "../Features.inc.in"
-  output = "$target_gen_dir/Features.inc"
-  values = []
-  if (clangd_build_xpc) {
-    values += [ "CLANGD_BUILD_XPC=1" ]
-  } else {
-    values += [ "CLANGD_BUILD_XPC=0" ]
-  }
-}
 
 executable("clangd") {
   configs += [ "//llvm/utils/gn/build:clang_code" ]
   deps = [
-    ":features",
     "//clang-tools-extra/clang-tidy",
     "//clang-tools-extra/clangd",
+    "//clang-tools-extra/clangd:features",
     "//clang-tools-extra/clangd/refactor/tweaks",
     "//clang/lib/AST",
     "//clang/lib/Basic",
     "//clang/lib/Format",
     "//clang/lib/Frontend",
     "//clang/lib/Sema",
     "//clang/lib/Tooling",
     "//clang/lib/Tooling/Core",
     "//llvm/lib/Support",
   ]
   if (clangd_build_xpc) {
     deps += [
       "//clang-tools-extra/clangd/xpc:conversions",
       "//clang-tools-extra/clangd/xpc:transport",
     ]
   }
 
-  include_dirs = [
-    "..",
-
-    # To pick up the generated inc files.
-    "$target_gen_dir",
-  ]
+  include_dirs = [ ".." ]
   sources = [
     "ClangdMain.cpp",
   ]
 }

llvm/utils/gn/secondary/clang-tools-extra/unittests/clangd/BUILD.gn

 import("//llvm/utils/unittest/unittest.gni")
 
 unittest("ClangdTests") {
   configs += [ "//llvm/utils/gn/build:clang_code" ]
   deps = [
     "//clang-tools-extra/clang-tidy",
     "//clang-tools-extra/clangd",
+    "//clang-tools-extra/clangd:features",
     "//clang-tools-extra/clangd/refactor/tweaks",
     "//clang/lib/AST",
     "//clang/lib/Basic",
     "//clang/lib/Format",
     "//clang/lib/Frontend",
     "//clang/lib/Index",
     "//clang/lib/Lex",
     "//clang/lib/Sema",