debuginfo: Show warnings if .debug sections are absent

Actually, `.debug_line` section is checked (implicitly by debugedit)
which should go together with all `.debug_*` sections. This
simplification will make check faster.

Note: Only non-stripped binaries are checked.

Spelling fixes, usage of `Warning' function, and redirect to stderr is
suggested by Dmitry V. Levin <ldv@altlinux.org>.

scripts/brp-debuginfo.in

@@ -77,3 +77,13 @@ while read -r l; do
 	mkdir -p .debuginfo/links/"${debugf%/*}"
 	printf '%s\n' "${debugl#.}" >>.debuginfo/links/"$debugf"
 done <.tmp/flist
+
+if [ -s .tmp/no_debug_info ]; then
+	howmuch=$(wc -l < .tmp/no_debug_info)
+	Warning "$howmuch non-stripped binaries don't contain .debug sections making -debuginfo"
+	Warning "package less relevant. An excerpt from the list of affected files follows:"
+	sed 's/^/  /; 10q' < .tmp/no_debug_info >&2
+	if egrep -q '/lib/modules/.*(/vmlinux|\.ko)$' .tmp/no_debug_info; then
+		Warning "Please enable CONFIG_DEBUG_INFO=y in the kernel package!"
+	fi
+fi

scripts/process-debuginfo.in

@@ -84,6 +84,7 @@ while read -r src; do
 	fi
 	printf '%s\n' /usr/src/debug/"$src"
 done >.debuginfo/src/"$f"
+[ -s .tmp/src.$$ ] || printf '%s\n' "$f" >> .tmp/no_debug_info
 rm .tmp/src.$$
 
 if [ -n "$rezip" ]; then