tests: minor improvement of sc_tight_scope rule

* src/Makefile.am (sc_tight_scope): Adjust rule to use an eval-based
trap-setting for-loop rather than 4x hard-coded 128+N constants.
Also catch SIGQUIT (3).  Tweak comments.

diff --git a/src/Makefile.am b/src/Makefile.am
index 5bd71d2..1727d67 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -707,8 +707,8 @@ sc_check-AUTHORS: $(all_programs)
 
 # Most functions in src/*.c should have static scope.
 # Any that don't must be marked with `extern', but `main'
-# and `usage' are exceptions.  They're always extern, but
-# don't need to be marked. Also functions starting with __
+# and `usage' are exceptions: they're always extern, but
+# do not need to be marked.  Also functions starting with __
 # are exempted due to possibly being added by the compiler
 # (when compiled as a shared library for example).
 #
@@ -717,9 +717,9 @@ sc_check-AUTHORS: $(all_programs)
 sc_tight_scope: $(bin_PROGRAMS)
        @t=exceptions-$$$$;                                             \
        trap 's=$$?; rm -f $$t; exit $$s' 0;                            \
-       am__exit='(exit $s); exit $s';                                  \
-       trap "s=129; $$am__exit" 1; trap "s=130; $$am__exit" 2;         \
-       trap "s=141; $$am__exit" 13; trap "s=143; $$am__exit" 15;       \
+       for sig in 1 2 3 13 15; do                                      \
+         eval "trap 'v=`expr $$sig + 128`; (exit $$v); exit $$v' $$sig"; \
+       done;                                                           \
        src=`for f in $(SOURCES); do                                    \
               test -f $$f && d= || d=$(srcdir)/; echo $$d$$f; done`;   \
        hdr=`for f in $(noinst_HEADERS); do                             \