diff --git a/llvm/utils/gn/secondary/llvm/lib/DebugInfo/DWARF/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/DWARF/BUILD.gn
new file mode 100644
index 000000000000..c93427ce636b
--- /dev/null
+++ b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/DWARF/BUILD.gn
@@ -0,0 +1,38 @@
+static_library("DWARF") {
+  output_name = "LLVMDebugInfoDWARF"
+  deps = [
+    "//llvm/lib/BinaryFormat",
+    "//llvm/lib/MC",
+    "//llvm/lib/Object",
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "DWARFAbbreviationDeclaration.cpp",
+    "DWARFAcceleratorTable.cpp",
+    "DWARFAddressRange.cpp",
+    "DWARFCompileUnit.cpp",
+    "DWARFContext.cpp",
+    "DWARFDataExtractor.cpp",
+    "DWARFDebugAbbrev.cpp",
+    "DWARFDebugAddr.cpp",
+    "DWARFDebugArangeSet.cpp",
+    "DWARFDebugAranges.cpp",
+    "DWARFDebugFrame.cpp",
+    "DWARFDebugInfoEntry.cpp",
+    "DWARFDebugLine.cpp",
+    "DWARFDebugLoc.cpp",
+    "DWARFDebugMacro.cpp",
+    "DWARFDebugPubTable.cpp",
+    "DWARFDebugRangeList.cpp",
+    "DWARFDebugRnglists.cpp",
+    "DWARFDie.cpp",
+    "DWARFExpression.cpp",
+    "DWARFFormValue.cpp",
+    "DWARFGdbIndex.cpp",
+    "DWARFListTable.cpp",
+    "DWARFTypeUnit.cpp",
+    "DWARFUnit.cpp",
+    "DWARFUnitIndex.cpp",
+    "DWARFVerifier.cpp",
+  ]
+}
diff --git a/llvm/utils/gn/secondary/llvm/lib/DebugInfo/PDB/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/PDB/BUILD.gn
new file mode 100644
index 000000000000..63057681ad0a
--- /dev/null
+++ b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/PDB/BUILD.gn
@@ -0,0 +1,118 @@
+import("//llvm/lib/DebugInfo/PDB/enable_dia.gni")
+
+static_library("PDB") {
+  output_name = "LLVMDebugInfoPDB"
+  deps = [
+    "//llvm/include/llvm/Config:config",
+    "//llvm/lib/DebugInfo/CodeView",
+    "//llvm/lib/DebugInfo/MSF",
+    "//llvm/lib/Object",
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "GenericError.cpp",
+    "IPDBSourceFile.cpp",
+    "Native/DbiModuleDescriptor.cpp",
+    "Native/DbiModuleDescriptorBuilder.cpp",
+    "Native/DbiModuleList.cpp",
+    "Native/DbiStream.cpp",
+    "Native/DbiStreamBuilder.cpp",
+    "Native/EnumTables.cpp",
+    "Native/GSIStreamBuilder.cpp",
+    "Native/GlobalsStream.cpp",
+    "Native/Hash.cpp",
+    "Native/HashTable.cpp",
+    "Native/InfoStream.cpp",
+    "Native/InfoStreamBuilder.cpp",
+    "Native/ModuleDebugStream.cpp",
+    "Native/NamedStreamMap.cpp",
+    "Native/NativeCompilandSymbol.cpp",
+    "Native/NativeEnumGlobals.cpp",
+    "Native/NativeEnumModules.cpp",
+    "Native/NativeEnumTypes.cpp",
+    "Native/NativeExeSymbol.cpp",
+    "Native/NativeRawSymbol.cpp",
+    "Native/NativeSession.cpp",
+    "Native/NativeSymbolEnumerator.cpp",
+    "Native/NativeTypeArray.cpp",
+    "Native/NativeTypeBuiltin.cpp",
+    "Native/NativeTypeEnum.cpp",
+    "Native/NativeTypeFunctionSig.cpp",
+    "Native/NativeTypePointer.cpp",
+    "Native/NativeTypeTypedef.cpp",
+    "Native/NativeTypeUDT.cpp",
+    "Native/NativeTypeVTShape.cpp",
+    "Native/PDBFile.cpp",
+    "Native/PDBFileBuilder.cpp",
+    "Native/PDBStringTable.cpp",
+    "Native/PDBStringTableBuilder.cpp",
+    "Native/PublicsStream.cpp",
+    "Native/RawError.cpp",
+    "Native/SymbolCache.cpp",
+    "Native/SymbolStream.cpp",
+    "Native/TpiHashing.cpp",
+    "Native/TpiStream.cpp",
+    "Native/TpiStreamBuilder.cpp",
+    "PDB.cpp",
+    "PDBContext.cpp",
+    "PDBExtras.cpp",
+    "PDBInterfaceAnchors.cpp",
+    "PDBSymDumper.cpp",
+    "PDBSymbol.cpp",
+    "PDBSymbolAnnotation.cpp",
+    "PDBSymbolBlock.cpp",
+    "PDBSymbolCompiland.cpp",
+    "PDBSymbolCompilandDetails.cpp",
+    "PDBSymbolCompilandEnv.cpp",
+    "PDBSymbolCustom.cpp",
+    "PDBSymbolData.cpp",
+    "PDBSymbolExe.cpp",
+    "PDBSymbolFunc.cpp",
+    "PDBSymbolFuncDebugEnd.cpp",
+    "PDBSymbolFuncDebugStart.cpp",
+    "PDBSymbolLabel.cpp",
+    "PDBSymbolPublicSymbol.cpp",
+    "PDBSymbolThunk.cpp",
+    "PDBSymbolTypeArray.cpp",
+    "PDBSymbolTypeBaseClass.cpp",
+    "PDBSymbolTypeBuiltin.cpp",
+    "PDBSymbolTypeCustom.cpp",
+    "PDBSymbolTypeDimension.cpp",
+    "PDBSymbolTypeEnum.cpp",
+    "PDBSymbolTypeFriend.cpp",
+    "PDBSymbolTypeFunctionArg.cpp",
+    "PDBSymbolTypeFunctionSig.cpp",
+    "PDBSymbolTypeManaged.cpp",
+    "PDBSymbolTypePointer.cpp",
+    "PDBSymbolTypeTypedef.cpp",
+    "PDBSymbolTypeUDT.cpp",
+    "PDBSymbolTypeVTable.cpp",
+    "PDBSymbolTypeVTableShape.cpp",
+    "PDBSymbolUnknown.cpp",
+    "PDBSymbolUsingNamespace.cpp",
+    "UDTLayout.cpp",
+  ]
+  if (llvm_enable_dia_sdk) {
+    sources += [
+      "DIA/DIADataStream.cpp",
+      "DIA/DIAEnumDebugStreams.cpp",
+      "DIA/DIAEnumFrameData.cpp",
+      "DIA/DIAEnumInjectedSources.cpp",
+      "DIA/DIAEnumLineNumbers.cpp",
+      "DIA/DIAEnumSectionContribs.cpp",
+      "DIA/DIAEnumSourceFiles.cpp",
+      "DIA/DIAEnumSymbols.cpp",
+      "DIA/DIAEnumTables.cpp",
+      "DIA/DIAError.cpp",
+      "DIA/DIAFrameData.cpp",
+      "DIA/DIAInjectedSource.cpp",
+      "DIA/DIALineNumber.cpp",
+      "DIA/DIARawSymbol.cpp",
+      "DIA/DIASectionContrib.cpp",
+      "DIA/DIASession.cpp",
+      "DIA/DIASourceFile.cpp",
+      "DIA/DIATable.cpp",
+    ]
+    # FIXME: Link against the right diaguids.lib too.
+  }
+}
diff --git a/llvm/utils/gn/secondary/llvm/lib/DebugInfo/PDB/enable_dia.gni b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/PDB/enable_dia.gni
new file mode 100644
index 000000000000..9d397bcc9a4e
--- /dev/null
+++ b/llvm/utils/gn/secondary/llvm/lib/DebugInfo/PDB/enable_dia.gni
@@ -0,0 +1,4 @@
+declare_args() {
+  # Whether to build code that requires the Microsoft DIA SDK.
+  llvm_enable_dia_sdk = false
+}
diff --git a/llvm/utils/gn/secondary/llvm/lib/Option/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/Option/BUILD.gn
new file mode 100644
index 000000000000..51fe4651b168
--- /dev/null
+++ b/llvm/utils/gn/secondary/llvm/lib/Option/BUILD.gn
@@ -0,0 +1,12 @@
+static_library("Option") {
+  output_name = "LLVMOption"
+  deps = [
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "Arg.cpp",
+    "ArgList.cpp",
+    "OptTable.cpp",
+    "Option.cpp",
+  ]
+}
diff --git a/llvm/utils/gn/secondary/llvm/lib/Target/targets.gni b/llvm/utils/gn/secondary/llvm/lib/Target/targets.gni
index 97a8ae645ab6..76a3d57210cf 100644
--- a/llvm/utils/gn/secondary/llvm/lib/Target/targets.gni
+++ b/llvm/utils/gn/secondary/llvm/lib/Target/targets.gni
@@ -13,9 +13,7 @@ if (llvm_targets_to_build == "host") {
   }
 } else if (llvm_targets_to_build == "all") {
   # FIXME: Port the remaining targets.
-  llvm_targets_to_build = [
-    "X86",
-  ]
+  llvm_targets_to_build = [ "X86" ]
 }
 
 # Validate that llvm_targets_to_build is set to a list of valid targets,
diff --git a/llvm/utils/gn/secondary/llvm/lib/ToolDrivers/llvm-lib/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/ToolDrivers/llvm-lib/BUILD.gn
new file mode 100644
index 000000000000..0e8187c502c4
--- /dev/null
+++ b/llvm/utils/gn/secondary/llvm/lib/ToolDrivers/llvm-lib/BUILD.gn
@@ -0,0 +1,20 @@
+import("//llvm/utils/TableGen/tablegen.gni")
+
+tablegen("Options") {
+  visibility = [ ":LibDriver" ]
+  args = [ "-gen-opt-parser-defs" ]
+}
+
+static_library("LibDriver") {
+  output_name = "LLVMLibDriver"
+  deps = [
+    ":Options",
+    "//llvm/lib/BinaryFormat",
+    "//llvm/lib/Object",
+    "//llvm/lib/Option",
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "LibDriver.cpp",
+  ]
+}
diff --git a/llvm/utils/gn/secondary/llvm/lib/WindowsManifest/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/WindowsManifest/BUILD.gn
new file mode 100644
index 000000000000..d4c23c97397d
--- /dev/null
+++ b/llvm/utils/gn/secondary/llvm/lib/WindowsManifest/BUILD.gn
@@ -0,0 +1,11 @@
+static_library("WindowsManifest") {
+  output_name = "LLVMWindowsManifest"
+  deps = [
+    "//llvm/include/llvm/Config:config",
+    "//llvm/lib/Support",
+    "//llvm/utils/gn/build/libs/xml",
+  ]
+  sources = [
+    "WindowsManifestMerger.cpp",
+  ]
+}