[gn] port 584af2f (clang-tidy custom)

Author: nico

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

@@ -18,6 +18,10 @@ write_cmake_config("clang-tidy-config") {
     values += [ "CLANG_TIDY_ENABLE_STATIC_ANALYZER=" ]
   }
 
+  # FIXME: Add a setting? Tests seem to fail when it's not set though:
+  # https://github.com/llvm/llvm-project/pull/131804#issuecomment-3312465207
+  values += [ "CLANG_TIDY_ENABLE_QUERY_BASED_CUSTOM_CHECKS=1" ]
+
   # Let targets depending on this find the generated file.
   public_configs = [ ":clang-tidy-config_Config" ]
 }
@@ -73,6 +77,7 @@ group("all-checks") {
     "//clang-tools-extra/clang-tidy/cert",
     "//clang-tools-extra/clang-tidy/concurrency",
     "//clang-tools-extra/clang-tidy/cppcoreguidelines",
+    "//clang-tools-extra/clang-tidy/custom",
     "//clang-tools-extra/clang-tidy/darwin",
     "//clang-tools-extra/clang-tidy/fuchsia",
     "//clang-tools-extra/clang-tidy/google",

llvm/utils/gn/secondary/clang-tools-extra/clang-tidy/custom/BUILD.gn

@@ -0,0 +1,14 @@
+static_library("custom") {
+  output_name = "clangTidyCustomModule"
+  configs += [ "//llvm/utils/gn/build:clang_code" ]
+  deps = [
+    "//clang-tools-extra/clang-query",
+    "//clang-tools-extra/clang-tidy",
+    "//clang-tools-extra/clang-tidy/utils",
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "CustomTidyModule.cpp",
+    "QueryCheck.cpp",
+  ]
+}