diff --git a/libcxx/src/support/solaris/README b/libcxx/src/support/solaris/README.txt
rename from libcxx/src/support/solaris/README
rename to libcxx/src/support/solaris/README.txt
diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -187,7 +187,7 @@
     fi
     ${GIT_CLANG_FORMAT} \
         --diff \
-        --extensions ',h,hh,hpp,hxx,c,cc,cxx,cpp' HEAD~1 \
+        --extensions ',h,hpp,c,cpp,inc,ipp' HEAD~1 \
         -- $(find libcxx/{benchmarks,include,src}/ -type f | grep -vf libcxx/utils/data/ignore_format.txt) \
         | tee ${BUILD_DIR}/clang-format.patch
     # Check if the diff is empty, fail otherwise.
diff --git a/libcxx/utils/data/ignore_format.txt b/libcxx/utils/data/ignore_format.txt
--- a/libcxx/utils/data/ignore_format.txt
+++ b/libcxx/utils/data/ignore_format.txt
@@ -1,4 +1,3 @@
-libcxx/benchmarks/CMakeLists.txt
 libcxx/benchmarks/CartesianBenchmarks.h
 libcxx/benchmarks/ContainerBenchmarks.h
 libcxx/benchmarks/GenerateInput.h
@@ -29,8 +28,6 @@
 libcxx/benchmarks/format_to.bench.cpp
 libcxx/benchmarks/format_to_n.bench.cpp
 libcxx/benchmarks/function.bench.cpp
-libcxx/benchmarks/lit.cfg.py
-libcxx/benchmarks/lit.site.cfg.py.in
 libcxx/benchmarks/map.bench.cpp
 libcxx/benchmarks/ordered_set.bench.cpp
 libcxx/benchmarks/random.bench.cpp
@@ -38,7 +35,6 @@
 libcxx/benchmarks/stringstream.bench.cpp
 libcxx/benchmarks/unordered_set_operations.bench.cpp
 libcxx/benchmarks/vector_operations.bench.cpp
-libcxx/include/CMakeLists.txt
 libcxx/include/__algorithm/binary_search.h
 libcxx/include/__algorithm/clamp.h
 libcxx/include/__algorithm/comp.h
@@ -312,7 +308,6 @@
 libcxx/include/__concepts/totally_ordered.h
 libcxx/include/condition_variable
 libcxx/include/__config
-libcxx/include/__config_site.in
 libcxx/include/__coroutine/coroutine_handle.h
 libcxx/include/__coroutine/coroutine_traits.h
 libcxx/include/__coroutine/noop_coroutine_handle.h
@@ -470,7 +465,6 @@
 libcxx/include/__iterator/unreachable_sentinel.h
 libcxx/include/__iterator/wrap_iter.h
 libcxx/include/latch
-libcxx/include/libcxx.imp
 libcxx/include/limits
 libcxx/include/limits.h
 libcxx/include/list
@@ -506,7 +500,6 @@
 libcxx/include/__memory/uninitialized_algorithms.h
 libcxx/include/__memory/unique_ptr.h
 libcxx/include/__memory/uses_allocator.h
-libcxx/include/module.modulemap.in
 libcxx/include/mutex
 libcxx/include/__mutex_base
 libcxx/include/new
@@ -789,7 +782,6 @@
 libcxx/include/__verbose_abort
 libcxx/include/wchar.h
 libcxx/include/wctype.h
-libcxx/src/CMakeLists.txt
 libcxx/src/any.cpp
 libcxx/src/atomic.cpp
 libcxx/src/barrier.cpp
diff --git a/libcxx/utils/generate_ignore_format.sh b/libcxx/utils/generate_ignore_format.sh
--- a/libcxx/utils/generate_ignore_format.sh
+++ b/libcxx/utils/generate_ignore_format.sh
@@ -7,11 +7,22 @@
 fi
 
 rm libcxx/utils/data/ignore_format.txt
-for file in $(find libcxx/{benchmarks,include,src}/ -type f); do
+# This uses the same matches as the check-format CI step.
+#
+# Since it's hard to match empty extensions the following
+# method is used, remove all files with an extension, then
+# add the list of extensions that should be formatted.
+for file in $(find libcxx/{benchmarks,include,src}/ -type f -not -name '*.*' -or \( \
+	 -name "*.h" -or -name "*.hpp" -or \
+	 -name "*.c" -or -name "*.cpp" -or \
+	 -name "*.inc" -or -name "*.ipp" \
+	 \) ); do
+
   ${CLANG_FORMAT} --Werror --dry-run ${file} >& /dev/null
   if [ $? != 0 ]; then
     echo ${file} >> libcxx/utils/data/ignore_format.txt
   fi
 done
 
-sort libcxx/utils/data/ignore_format.txt -d -o libcxx/utils/data/ignore_format.txt
+# Force sorting not to depend on the system's locale.
+LC_ALL=C sort libcxx/utils/data/ignore_format.txt -d -o libcxx/utils/data/ignore_format.txt