Index: llvm/utils/gn/secondary/BUILD.gn
===================================================================
--- llvm/utils/gn/secondary/BUILD.gn
+++ llvm/utils/gn/secondary/BUILD.gn
@@ -1,7 +1,10 @@
 group("default") {
   deps = [
     "//clang/lib/Driver",
+    "//clang/lib/Frontend",
+    "//clang/lib/Frontend/Rewrite",
     "//clang/lib/Parse",
+    "//clang/lib/Serialization",
     "//clang/tools/clang-format",
     "//lld/test",
     "//llvm/tools/llvm-undname",
Index: llvm/utils/gn/secondary/clang/include/clang/Serialization/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/clang/include/clang/Serialization/BUILD.gn
@@ -0,0 +1,19 @@
+import("//clang/utils/TableGen/clang_tablegen.gni")
+
+clang_tablegen("AttrPCHRead") {
+  args = [
+    "-gen-clang-attr-pch-read",
+    "-I",
+    rebase_path("../..", root_out_dir),
+  ]
+  td_file = "../Basic/Attr.td"
+}
+
+clang_tablegen("AttrPCHWrite") {
+  args = [
+    "-gen-clang-attr-pch-write",
+    "-I",
+    rebase_path("../..", root_out_dir),
+  ]
+  td_file = "../Basic/Attr.td"
+}
Index: llvm/utils/gn/secondary/clang/lib/Frontend/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/clang/lib/Frontend/BUILD.gn
@@ -0,0 +1,54 @@
+static_library("Frontend") {
+  output_name = "clangFrontend"
+  configs += [ "//llvm/utils/gn/build:clang_code" ]
+  deps = [
+    "//clang/include/clang/Config",
+    "//clang/lib/AST",
+    "//clang/lib/Basic",
+    "//clang/lib/Driver",
+    "//clang/lib/Edit",
+    "//clang/lib/Lex",
+    "//clang/lib/Parse",
+    "//clang/lib/Sema",
+    "//clang/lib/Serialization",
+    "//llvm/include/llvm/Config:llvm-config",
+    "//llvm/lib/Bitcode/Reader",
+    "//llvm/lib/Option",
+    "//llvm/lib/ProfileData",
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "ASTConsumers.cpp",
+    "ASTMerge.cpp",
+    "ASTUnit.cpp",
+    "ChainedDiagnosticConsumer.cpp",
+    "ChainedIncludesSource.cpp",
+    "CompilerInstance.cpp",
+    "CompilerInvocation.cpp",
+    "CreateInvocationFromCommandLine.cpp",
+    "DependencyFile.cpp",
+    "DependencyGraph.cpp",
+    "DiagnosticRenderer.cpp",
+    "FrontendAction.cpp",
+    "FrontendActions.cpp",
+    "FrontendOptions.cpp",
+    "FrontendTiming.cpp",
+    "HeaderIncludeGen.cpp",
+    "InitHeaderSearch.cpp",
+    "InitPreprocessor.cpp",
+    "LangStandards.cpp",
+    "LayoutOverrideSource.cpp",
+    "LogDiagnosticPrinter.cpp",
+    "ModuleDependencyCollector.cpp",
+    "MultiplexConsumer.cpp",
+    "PrecompiledPreamble.cpp",
+    "PrintPreprocessedOutput.cpp",
+    "SerializedDiagnosticPrinter.cpp",
+    "SerializedDiagnosticReader.cpp",
+    "TestModuleFileExtension.cpp",
+    "TextDiagnostic.cpp",
+    "TextDiagnosticBuffer.cpp",
+    "TextDiagnosticPrinter.cpp",
+    "VerifyDiagnosticConsumer.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/clang/lib/Frontend/Rewrite/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/clang/lib/Frontend/Rewrite/BUILD.gn
@@ -0,0 +1,24 @@
+static_library("Rewrite") {
+  output_name = "clangRewriteFrontend"
+  configs += [ "//llvm/utils/gn/build:clang_code" ]
+  deps = [
+    "//clang/lib/AST",
+    "//clang/lib/Basic",
+    "//clang/lib/Edit",
+    "//clang/lib/Frontend",
+    "//clang/lib/Lex",
+    "//clang/lib/Rewrite",
+    "//clang/lib/Serialization",
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "FixItRewriter.cpp",
+    "FrontendActions.cpp",
+    "HTMLPrint.cpp",
+    "InclusionRewriter.cpp",
+    "RewriteMacros.cpp",
+    "RewriteModernObjC.cpp",
+    "RewriteObjC.cpp",
+    "RewriteTest.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/clang/lib/Serialization/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/clang/lib/Serialization/BUILD.gn
@@ -0,0 +1,31 @@
+static_library("Serialization") {
+  output_name = "clangSerialization"
+  configs += [ "//llvm/utils/gn/build:clang_code" ]
+  deps = [
+    "//clang/include/clang/Serialization:AttrPCHRead",
+    "//clang/include/clang/Serialization:AttrPCHWrite",
+    "//clang/lib/AST",
+    "//clang/lib/Basic",
+    "//clang/lib/Lex",
+    "//clang/lib/Sema",
+    "//llvm/lib/Bitcode/Reader",
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "ASTCommon.cpp",
+    "ASTCommon.h",
+    "ASTReader.cpp",
+    "ASTReaderDecl.cpp",
+    "ASTReaderInternals.h",
+    "ASTReaderStmt.cpp",
+    "ASTWriter.cpp",
+    "ASTWriterDecl.cpp",
+    "ASTWriterStmt.cpp",
+    "GeneratePCH.cpp",
+    "GlobalModuleIndex.cpp",
+    "Module.cpp",
+    "ModuleFileExtension.cpp",
+    "ModuleManager.cpp",
+    "PCHContainerOperations.cpp",
+  ]
+}