Create try_convert extension

GNUmakefile.in

@@ -43,6 +43,7 @@ ifeq ($(with_openssl), yes)
 	$(MAKE) -C contrib/sslinfo all
 endif
 	$(MAKE) -C contrib/tablefunc all
+	$(MAKE) -C contrib/try_convert all
 ifneq ($(with_uuid),no)
 	$(MAKE) -C contrib/uuid-ossp all
 endif
@@ -96,6 +97,7 @@ ifeq ($(with_openssl), yes)
 	$(MAKE) -C contrib/sslinfo $@
 endif
 	$(MAKE) -C contrib/tablefunc $@
+	$(MAKE) -C contrib/try_convert $@
 ifneq ($(with_uuid),no)
 	$(MAKE) -C contrib/uuid-ossp $@
 endif

contrib/Makefile

@@ -43,6 +43,7 @@ SUBDIRS = \
 		test_decoding	\
 		test_parser	\
 		test_shm_mq	\
+		try_convert \
 		tsearch2	\
 		tablefunc	\
 		unaccent

contrib/try_convert/Makefile

@@ -0,0 +1,19 @@
+# contrib/try_convert/Makefile
+
+MODULE_big	= try_convert
+OBJS		= try_convert.o $(WIN32RES)
+
+EXTENSION = try_convert
+DATA = try_convert--1.0.sql
+PGFILEDESC = "try_convert - function for type cast"
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/try_convert
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif

contrib/try_convert/try_convert--1.0.sql

@@ -0,0 +1,15 @@
+/* contrib/try_convert/try_convert--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION try_convert" to load this file. \quit
+
+/* ***********************************************
+ * try_convert function for PostgreSQL
+ * *********************************************** */
+
+/* generic file access functions */
+
+CREATE FUNCTION try_convert(anyelement, regtype)
+RETURNS int4
+AS 'MODULE_PATHNAME', 'try_convert'
+LANGUAGE C STRICT;

contrib/try_convert/try_convert.c

@@ -0,0 +1,24 @@
+#include "postgres.h"
+
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "postmaster/syslogger.h"
+#include "storage/fd.h"
+#include "utils/builtins.h"
+#include "utils/datetime.h"
+
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(try_convert);
+
+Datum
+try_convert(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT32(1);
+}

contrib/try_convert/try_convert.control

@@ -0,0 +1,5 @@
+# try_convert extension
+comment = 'function for type cast'
+default_version = '1.0'
+module_pathname = '$libdir/try_convert'
+relocatable = true