Don't use <ctype.h> functions

Makefile.am

@@ -37,9 +37,21 @@ clean-local:
 
 endif !HAVE_SHARED_LIBGTEST
 
-gentags: src/tag.in
+if PYTHON_FOUND
+if GPERF_FOUND
+@srcdir@/src/tag_gperf.h: src/tag.in gentags.py genperf.py
+	@echo GENPERF $<
 	@python gentags.py $<
-	@gperf -LANSI-C --ignore-case -m200 $< |python genperf.py >src/tag_gperf.h
+	@echo GPERF $<
+	@gperf -LANSI-C --ignore-case -m200 $< |python genperf.py >@srcdir@/src/tag_gperf.h
+endif
+endif
+
+if RAGEL_FOUND
+@srcdir@/src/char_ref.c: src/char_ref.rl
+	@echo RAGEL src/char_ref.rl
+	@cd @srcdir@/src && ragel -F0 char_ref.rl > char_ref.c
+endif
 
 lib_LTLIBRARIES = libgumbo.la
 libgumbo_la_CFLAGS = -Wall

configure.ac

@@ -11,6 +11,13 @@ AC_CONFIG_FILES([Makefile gumbo.pc])
 # Checks for programs.
 AC_PROG_CXX
 AC_PROG_CC_C99
+AC_DEFUN([GUMBO_CHECK_PROG],[dnl
+AC_ARG_VAR([$1],[$3])
+AC_CHECK_PROG([$1],[[$2]],[yes],[no])
+AM_CONDITIONAL([$1_FOUND],[[[ "x${$1}" = 'xyes' ]]])])
+GUMBO_CHECK_PROG([PYTHON],[python],[Path to python interpreter])
+GUMBO_CHECK_PROG([RAGEL],[ragel],[Path to ragel state-machine compiler])
+GUMBO_CHECK_PROG([GPERF],[gperf],[Path to gperf perfect-hash function generator])
 
 # Checks for libraries.