Avoid direct cross-module links in hstore_plperl and ltree_plpython, too.

Just turning the crank on the project started in commit d51924be8.
These cases turn out to be exact subsets of the boilerplate needed
for hstore_plpython.

Discussion: <2652.1475512158@sss.pgh.pa.us>

1 files changed, 54 insertions, 0 deletions

diff --git a/contrib/hstore_plperl/hstore_plperl.c b/contrib/hstore_plperl/hstore_plperl.c
index d40a7927307..480212f341e 100644
--- a/contrib/hstore_plperl/hstore_plperl.c
+++ b/contrib/hstore_plperl/hstore_plperl.c
@@ -1,5 +1,7 @@
 #include "postgres.h"
+
 #undef _
+
 #include "fmgr.h"
 #include "plperl.h"
 #include "plperl_helpers.h"
@@ -7,6 +9,58 @@
 
 PG_MODULE_MAGIC;
 
+extern void _PG_init(void);
+
+/* Linkage to functions in hstore module */
+typedef HStore *(*hstoreUpgrade_t) (Datum orig);
+static hstoreUpgrade_t hstoreUpgrade_p;
+typedef int (*hstoreUniquePairs_t) (Pairs *a, int32 l, int32 *buflen);
+static hstoreUniquePairs_t hstoreUniquePairs_p;
+typedef HStore *(*hstorePairs_t) (Pairs *pairs, int32 pcount, int32 buflen);
+static hstorePairs_t hstorePairs_p;
+typedef size_t (*hstoreCheckKeyLen_t) (size_t len);
+static hstoreCheckKeyLen_t hstoreCheckKeyLen_p;
+typedef size_t (*hstoreCheckValLen_t) (size_t len);
+static hstoreCheckValLen_t hstoreCheckValLen_p;
+
+
+/*
+ * Module initialize function: fetch function pointers for cross-module calls.
+ */
+void
+_PG_init(void)
+{
+	/* Asserts verify that typedefs above match original declarations */
+	AssertVariableIsOfType(&hstoreUpgrade, hstoreUpgrade_t);
+	hstoreUpgrade_p = (hstoreUpgrade_t)
+		load_external_function("$libdir/hstore", "hstoreUpgrade",
+							   true, NULL);
+	AssertVariableIsOfType(&hstoreUniquePairs, hstoreUniquePairs_t);
+	hstoreUniquePairs_p = (hstoreUniquePairs_t)
+		load_external_function("$libdir/hstore", "hstoreUniquePairs",
+							   true, NULL);
+	AssertVariableIsOfType(&hstorePairs, hstorePairs_t);
+	hstorePairs_p = (hstorePairs_t)
+		load_external_function("$libdir/hstore", "hstorePairs",
+							   true, NULL);
+	AssertVariableIsOfType(&hstoreCheckKeyLen, hstoreCheckKeyLen_t);
+	hstoreCheckKeyLen_p = (hstoreCheckKeyLen_t)
+		load_external_function("$libdir/hstore", "hstoreCheckKeyLen",
+							   true, NULL);
+	AssertVariableIsOfType(&hstoreCheckValLen, hstoreCheckValLen_t);
+	hstoreCheckValLen_p = (hstoreCheckValLen_t)
+		load_external_function("$libdir/hstore", "hstoreCheckValLen",
+							   true, NULL);
+}
+
+
+/* These defines must be after the module init function */
+#define hstoreUpgrade hstoreUpgrade_p
+#define hstoreUniquePairs hstoreUniquePairs_p
+#define hstorePairs hstorePairs_p
+#define hstoreCheckKeyLen hstoreCheckKeyLen_p
+#define hstoreCheckValLen hstoreCheckValLen_p
+
 
 PG_FUNCTION_INFO_V1(hstore_to_plperl);