Index: lld/test/CMakeLists.txt
===================================================================
--- lld/test/CMakeLists.txt
+++ lld/test/CMakeLists.txt
@@ -14,7 +14,9 @@
 endif()
 
 llvm_canonicalize_cmake_booleans(
-  HAVE_LIBZ)
+  HAVE_LIBZ
+  LLVM_LIBXML2_ENABLED
+  )
 
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.py.in
Index: lld/test/lit.cfg.py
===================================================================
--- lld/test/lit.cfg.py
+++ lld/test/lit.cfg.py
@@ -88,10 +88,10 @@
 # cvtres, which always accompanies it.  Alternatively, check if we can use
 # libxml2 to merge manifests.
 if (lit.util.which('cvtres', config.environment['PATH'])) or \
-        (config.llvm_libxml2_enabled == '1'):
+        config.llvm_libxml2_enabled:
     config.available_features.add('manifest_tool')
 
-if (config.llvm_libxml2_enabled == '1'):
+if config.llvm_libxml2_enabled:
     config.available_features.add('libxml2')
 
 if config.have_dia_sdk:
Index: lld/test/lit.site.cfg.py.in
===================================================================
--- lld/test/lit.site.cfg.py.in
+++ lld/test/lit.site.cfg.py.in
@@ -7,7 +7,7 @@
 config.llvm_obj_root = "@LLVM_BINARY_DIR@"
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.llvm_libs_dir = "@LLVM_LIBS_DIR@"
-config.llvm_libxml2_enabled = "@LLVM_LIBXML2_ENABLED@"
+config.llvm_libxml2_enabled = @LLVM_LIBXML2_ENABLED@
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.lld_obj_root = "@LLD_BINARY_DIR@"
 config.lld_libs_dir = "@LLVM_LIBRARY_OUTPUT_INTDIR@"
Index: llvm/test/CMakeLists.txt
===================================================================
--- llvm/test/CMakeLists.txt
+++ llvm/test/CMakeLists.txt
@@ -1,16 +1,17 @@
 llvm_canonicalize_cmake_booleans(
-  LLVM_TOOL_LTO_BUILD
+  BUILD_SHARED_LIBS
+  HAVE_LIBXAR
+  HAVE_LIBZ
   HAVE_OCAMLOPT
   HAVE_OCAML_OUNIT
-  LLVM_INCLUDE_GO_TESTS
-  LLVM_USE_INTEL_JITEVENTS
-  HAVE_LIBZ
-  HAVE_LIBXAR
   LLVM_ENABLE_DIA_SDK
   LLVM_ENABLE_FFI
   LLVM_ENABLE_THREADS
-  BUILD_SHARED_LIBS
+  LLVM_INCLUDE_GO_TESTS
+  LLVM_LIBXML2_ENABLED
   LLVM_LINK_LLVM_DYLIB
+  LLVM_TOOL_LTO_BUILD
+  LLVM_USE_INTEL_JITEVENTS
   )
 
 configure_lit_site_cfg(
Index: llvm/test/lit.cfg.py
===================================================================
--- llvm/test/lit.cfg.py
+++ llvm/test/lit.cfg.py
@@ -324,7 +324,7 @@
 if config.enable_threads:
     config.available_features.add('thread_support')
 
-if config.llvm_libxml2_enabled == '1':
+if config.llvm_libxml2_enabled:
     config.available_features.add('libxml2')
 
 if config.have_opt_viewer_modules:
Index: llvm/test/lit.site.cfg.py.in
===================================================================
--- llvm/test/lit.site.cfg.py.in
+++ llvm/test/lit.site.cfg.py.in
@@ -39,7 +39,7 @@
 config.enable_threads = @LLVM_ENABLE_THREADS@
 config.build_shared_libs = @BUILD_SHARED_LIBS@
 config.link_llvm_dylib = @LLVM_LINK_LLVM_DYLIB@
-config.llvm_libxml2_enabled = "@LLVM_LIBXML2_ENABLED@"
+config.llvm_libxml2_enabled = @LLVM_LIBXML2_ENABLED@
 config.llvm_host_triple = '@LLVM_HOST_TRIPLE@'
 config.host_arch = "@HOST_ARCH@"
 config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@
Index: llvm/utils/gn/TODO.txt
===================================================================
--- llvm/utils/gn/TODO.txt
+++ llvm/utils/gn/TODO.txt
@@ -20,8 +20,6 @@
 - add dead code stripping
 - move run_tablegen.py from build to tablegen folder
 - figure out why -Iclang/Support gets added so often
-- make LLVM_LIBXML2_ENABLED use llvm_canonicalize_cmake_boolean (cf D28294),
-  clean up both GN and CMake builds
 - plugin() template with working rpath, exports thingers
   - then port clang_build_examples and enable by default so that clang
     plugin tests run by default
Index: llvm/utils/gn/secondary/lld/test/BUILD.gn
===================================================================
--- llvm/utils/gn/secondary/lld/test/BUILD.gn
+++ llvm/utils/gn/secondary/lld/test/BUILD.gn
@@ -45,7 +45,7 @@
   if (llvm_enable_libxml2) {
     extra_values += [ "LLVM_LIBXML2_ENABLED=1" ]
   } else {
-    extra_values += [ "LLVM_LIBXML2_ENABLED=" ]  # Must be empty.
+    extra_values += [ "LLVM_LIBXML2_ENABLED=0" ]  # Must be 0.
   }
 
   if (llvm_enable_zlib) {
Index: llvm/utils/gn/secondary/llvm/test/BUILD.gn
===================================================================
--- llvm/utils/gn/secondary/llvm/test/BUILD.gn
+++ llvm/utils/gn/secondary/llvm/test/BUILD.gn
@@ -140,7 +140,7 @@
   if (llvm_enable_libxml2) {
     extra_values += [ "LLVM_LIBXML2_ENABLED=1" ]
   } else {
-    extra_values += [ "LLVM_LIBXML2_ENABLED=" ]  # Must be empty.
+    extra_values += [ "LLVM_LIBXML2_ENABLED=0" ]  # Must be 0.
   }
 
   if (llvm_enable_threads) {