[PATCH 1/1] Add lint-makefiles Makefile linting test.

[Carlos O'Donell <carlos@redhat.com>]

We add a `make check` test that lints all Makefiles in the source
directory of the glibc build. This linting test ensures that the
lines in all Makefiles will be sorted correctly as developers
creates patches.

The test adds ~3s to a test run.

No regressions on x86_64 and i686.
---
 Makefile                  |  6 +++++
 scripts/lint-makefiles.sh | 47 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 scripts/lint-makefiles.sh

diff --git a/Makefile b/Makefile
index 224c792185..93e5a60af9 100644
--- a/Makefile
+++ b/Makefile
@@ -564,6 +564,12 @@ $(objpfx)check-wrapper-headers.out: scripts/check-wrapper-headers.py $(headers)
 	  --generated $(common-generated) > $@; $(evaluate-test)
 endif # $(headers)
 
+# Lint all Makefiles including this one to check for correctly sorted lines.
+tests-special += $(objpfx)lint-makefiles.out
+$(objpfx)lint-makefiles.out: scripts/lint-makefiles.sh
+	$(SHELL) $< "$(PYTHON)" "$(srcdir)" > $@ ; \
+	$(evaluate-test)
+
 define summarize-tests
 @grep -E -v '^(PASS|XFAIL):' $(objpfx)$1 || true
 @echo "Summary of test results$2:"
diff --git a/scripts/lint-makefiles.sh b/scripts/lint-makefiles.sh
new file mode 100644
index 0000000000..cf63a4ab9f
--- /dev/null
+++ b/scripts/lint-makefiles.sh
@@ -0,0 +1,47 @@
+#!/bin/bash
+# Copyright (C) 2023 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+
+# This script checks to see that all Makefiles in the source tree
+# conform to the sorted variable rules as defined by:
+# scripts/sort-makefile-lines.py.
+# Any difference is an error and should be corrected e.g. the lines
+# reordered to sort correctly.
+# The intent with this check is to ensure that changes made by
+# developers match the expected format for the project.
+
+set -e
+export LC_ALL=C
+
+tmpfile="$(mktemp)"
+
+cleanup () {
+  rm -f -- "$tmpfile"
+}
+
+trap cleanup 0
+
+PYTHON=$1
+srcdir=$2
+
+echo "Linting Makefiles:"
+echo "Check: Are all lines sorted correctly?"
+for mfile in `find "$srcdir" -name Makefile`; do
+    echo "$mfile"
+    $PYTHON "${srcdir}scripts/sort-makefile-lines.py" < "$mfile" > "$tmpfile"
+    diff -q "$mfile" "$tmpfile"
+done
-- 
2.40.0