MINOR: initcall: use initcalls for section parsers

The two calls to cfg_register_section() and cfg_register_postparser()
are now supported by initcalls. This allowed to remove two other
constructors.
diff --git a/include/common/cfgparse.h b/include/common/cfgparse.h
index 3069722..b46e02b 100644
--- a/include/common/cfgparse.h
+++ b/include/common/cfgparse.h
@@ -24,6 +24,7 @@
 
 #include <common/compat.h>
 #include <common/config.h>
+#include <common/initcall.h>
 #include <common/mini-clist.h>
 
 #include <proto/log.h>
@@ -143,6 +144,13 @@
 	return 0;
 }
 
+/* simplified way to define a section parser */
+#define REGISTER_CONFIG_SECTION(name, parse, post)                            \
+	INITCALL3(STG_REGISTER, cfg_register_section, (name), (parse), (post))
+
+#define REGISTER_CONFIG_POSTPARSER(name, parser)                              \
+	INITCALL2(STG_REGISTER, cfg_register_postparser, (name), (parser))
+
 #endif /* _COMMON_CFGPARSE_H */
 
 /*
diff --git a/src/cache.c b/src/cache.c
index acab99d..7f1de9f 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -1215,7 +1215,9 @@
 __attribute__((constructor))
 static void __cache_init(void)
 {
-	cfg_register_section("cache", cfg_parse_cache, cfg_post_parse_section_cache);
-	cfg_register_postparser("cache", cfg_cache_postparser);
 	pool_head_cache_st = create_pool("cache_st", sizeof(struct cache_st), MEM_F_SHARED);
 }
+
+/* config parsers for this section */
+REGISTER_CONFIG_SECTION("cache", cfg_parse_cache, cfg_post_parse_section_cache);
+REGISTER_CONFIG_POSTPARSER("cache", cfg_cache_postparser);
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 1e65668..5df53d3 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -3851,21 +3851,17 @@
 	}
 }
 
-__attribute__((constructor))
-static void cfgparse_init(void)
-{
-	/* Register internal sections */
-	cfg_register_section("listen",         cfg_parse_listen,    NULL);
-	cfg_register_section("frontend",       cfg_parse_listen,    NULL);
-	cfg_register_section("backend",        cfg_parse_listen,    NULL);
-	cfg_register_section("defaults",       cfg_parse_listen,    NULL);
-	cfg_register_section("global",         cfg_parse_global,    NULL);
-	cfg_register_section("userlist",       cfg_parse_users,     NULL);
-	cfg_register_section("peers",          cfg_parse_peers,     NULL);
-	cfg_register_section("mailers",        cfg_parse_mailers,   NULL);
-	cfg_register_section("namespace_list", cfg_parse_netns,     NULL);
-	cfg_register_section("resolvers",      cfg_parse_resolvers, NULL);
-}
+/* these are the config sections handled by default */
+REGISTER_CONFIG_SECTION("listen",         cfg_parse_listen,    NULL);
+REGISTER_CONFIG_SECTION("frontend",       cfg_parse_listen,    NULL);
+REGISTER_CONFIG_SECTION("backend",        cfg_parse_listen,    NULL);
+REGISTER_CONFIG_SECTION("defaults",       cfg_parse_listen,    NULL);
+REGISTER_CONFIG_SECTION("global",         cfg_parse_global,    NULL);
+REGISTER_CONFIG_SECTION("userlist",       cfg_parse_users,     NULL);
+REGISTER_CONFIG_SECTION("peers",          cfg_parse_peers,     NULL);
+REGISTER_CONFIG_SECTION("mailers",        cfg_parse_mailers,   NULL);
+REGISTER_CONFIG_SECTION("namespace_list", cfg_parse_netns,     NULL);
+REGISTER_CONFIG_SECTION("resolvers",      cfg_parse_resolvers, NULL);
 
 /*
  * Local variables:
diff --git a/src/dns.c b/src/dns.c
index 255f15a..2aac74f 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -2058,8 +2058,7 @@
 {
 	dns_answer_item_pool = create_pool("dns_answer_item", sizeof(struct dns_answer_item), MEM_F_SHARED);
 	dns_resolution_pool  = create_pool("dns_resolution",  sizeof(struct dns_resolution),  MEM_F_SHARED);
-
-	cfg_register_postparser("dns runtime resolver", dns_finalize_config);
 }
 
 REGISTER_POST_DEINIT(dns_deinit);
+REGISTER_CONFIG_POSTPARSER("dns runtime resolver", dns_finalize_config);
diff --git a/src/hlua.c b/src/hlua.c
index 294b6b3..379eef6 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -8207,12 +8207,6 @@
 	RESET_SAFE_LJMP(gL.T);
 }
 
-__attribute__((constructor))
-static void __hlua_init(void)
-{
-	cfg_register_postparser("hlua", hlua_check_config);
-}
-
 static void hlua_register_build_options(void)
 {
 	char *ptr = NULL;
@@ -8222,3 +8216,4 @@
 }
 
 INITCALL0(STG_REGISTER, hlua_register_build_options);
+REGISTER_CONFIG_POSTPARSER("hlua", hlua_check_config);