configure: Fix gperf length parameter determination

gperf is not actually a build dependency as the generated files are
shipped in the tarball.  So the type depends on the gperf version on
the host that ran gperf and created the tarball, which might not be
the same as that on the actual build host, and gperf might not even
be installed there, leaving the type undetermined.

Fixes: e0e4322973 ("configure: Detect type of length parameter for gperf generated function")

src/starter/.gitignore

@@ -1,4 +1,5 @@
 starter
+keywords.[ch]
 parser/lexer.c
 parser/parser.[ch]
 parser/parser.output

src/starter/Makefile.am

@@ -39,14 +39,20 @@ starter_LDADD = \
 	libstarter.la \
 	$(SOCKLIB) $(PTHREADLIB) $(ATOMICLIB)
 
-EXTRA_DIST = keywords.txt ipsec.conf ipsec.secrets Android.mk
-MAINTAINERCLEANFILES = keywords.c
-BUILT_SOURCES = keywords.c parser/parser.h
+EXTRA_DIST = keywords.h keywords.txt ipsec.conf ipsec.secrets Android.mk
+MAINTAINERCLEANFILES = keywords.h keywords.c
+BUILT_SOURCES = keywords.h keywords.c parser/parser.h
 
 if USE_LOAD_WARNING
   AM_CPPFLAGS += -DLOAD_WARNING
 endif
 
+keywords.h: $(srcdir)/keywords.h.in
+		$(AM_V_GEN) \
+		sed \
+		-e "s:\@GPERF_LEN_TYPE\@:$(GPERF_LEN_TYPE):" \
+		$< > $@
+
 keywords.c:	$(srcdir)/keywords.txt $(srcdir)/keywords.h
 		$(AM_V_GEN) \
 		$(GPERF) -m 10 -C -G -D -t < $(srcdir)/keywords.txt > $@

src/starter/confread.c

@@ -45,11 +45,6 @@ static const char esp_defaults[] = "aes128-sha256";
 
 static const char firewall_defaults[] = IPSEC_SCRIPT " _updown iptables";
 
-/**
- * Provided by GPERF
- */
-extern const kw_entry_t *in_word_set(register const char*, register GPERF_LEN_TYPE);
-
 /**
  * Process deprecated keywords
  */

src/starter/keywords.h.in

@@ -196,4 +196,8 @@ struct kw_entry_t {
 	kw_token_t token;
 };
 
+#ifndef IN_GPERF_GENERATED_FILE
+const kw_entry_t *in_word_set(register const char*, register @GPERF_LEN_TYPE@);
+#endif
+
 #endif /* _KEYWORDS_H_ */

src/starter/keywords.txt

@@ -16,6 +16,7 @@
 
 #include <string.h>
 
+#define IN_GPERF_GENERATED_FILE
 #include "keywords.h"
 
 %}