lint-generic: Check that shebang-presence and executable bit match

1 files changed, 15 insertions, 0 deletions

diff --git a/build-aux/lint-generic b/build-aux/lint-generic
index fcc0457..c02dc34 100755
--- a/build-aux/lint-generic
+++ b/build-aux/lint-generic
@@ -15,14 +15,26 @@ err() {
 r=0
 for filename in "$@"; do
 	if ! { [ -f "$filename" ] && ! [ -h "$filename" ]; }; then
+		# Ignore non-files
 		continue
 	fi
+
+	# File header ##########################################################
+
+	shebang="$(sed -n '1{/^#!/{/^#!\/hint\//q; p;};}' "$filename")"
+	if [ -x "$filename" ] && [ -z "$shebang" ]; then
+		err "$filename" 'is executable but does not have a shebang'
+	elif [ -n "$shebang" ] && ! [ -x "$filename" ]; then
+		err "$filename" 'has a shebang but is executable'
+	fi
+
 	if ! grep -E -q 'Copyright \(C\) 202[4-9]((-|, )202[5-9])*  Luke T. Shumaker' "$filename"; then
 		err "$filename" 'is missing a copyright statement'
 	fi
 	if ! grep -q ' SPDX-License-Identifier[:] ' "$filename"; then
 		err "$filename" 'is missing an SPDX-License-Identifier'
 	fi
+
 	dscname_act=$(./build-aux/get-dscname "$filename")
 	dscname_exp=$(echo "$filename" | sed \
 		-e 's,.*/config/,,' \
@@ -32,6 +44,9 @@ for filename in "$@"; do
 	if [ "$dscname_act" != "$dscname_exp" ] && [ "cmd/$dscname_act" != "$dscname_exp" ]; then
 		err "$filename" "self-identifies as $dscname_act (expected $dscname_exp)"
 	fi
+
+	# File body ############################################################
+
 	if grep -n --color=auto "$(printf '\\S\t')" "$filename"; then
 		err "$filename" 'uses tabs for alignment'
 	fi