Adding upstream version 15.5.upstream/15.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3291 insertions, 0 deletions

diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c
new file mode 100644
index 0000000..11f1ff1
--- /dev/null
+++ b/src/pl/tcl/pltcl.c
@@ -0,0 +1,3291 @@
+/**********************************************************************
+ * pltcl.c		- PostgreSQL support for Tcl as
+ *				  procedural language (PL)
+ *
+ *	  src/pl/tcl/pltcl.c
+ *
+ **********************************************************************/
+
+#include "postgres.h"
+
+#include <tcl.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "access/htup_details.h"
+#include "access/xact.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_proc.h"
+#include "catalog/pg_type.h"
+#include "commands/event_trigger.h"
+#include "commands/trigger.h"
+#include "executor/spi.h"
+#include "fmgr.h"
+#include "funcapi.h"
+#include "mb/pg_wchar.h"
+#include "miscadmin.h"
+#include "nodes/makefuncs.h"
+#include "parser/parse_func.h"
+#include "parser/parse_type.h"
+#include "pgstat.h"
+#include "tcop/tcopprot.h"
+#include "utils/acl.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/regproc.h"
+#include "utils/rel.h"
+#include "utils/syscache.h"
+#include "utils/typcache.h"
+
+
+PG_MODULE_MAGIC;
+
+#define HAVE_TCL_VERSION(maj,min) \
+	((TCL_MAJOR_VERSION > maj) || \
+	 (TCL_MAJOR_VERSION == maj && TCL_MINOR_VERSION >= min))
+
+/* Insist on Tcl >= 8.4 */
+#if !HAVE_TCL_VERSION(8,4)
+#error PostgreSQL only supports Tcl 8.4 or later.
+#endif
+
+/* Hack to deal with Tcl 8.6 const-ification without losing compatibility */
+#ifndef CONST86
+#define CONST86
+#endif
+
+/* define our text domain for translations */
+#undef TEXTDOMAIN
+#define TEXTDOMAIN PG_TEXTDOMAIN("pltcl")
+
+
+/*
+ * Support for converting between UTF8 (which is what all strings going into
+ * or out of Tcl should be) and the database encoding.
+ *
+ * If you just use utf_u2e() or utf_e2u() directly, they will leak some
+ * palloc'd space when doing a conversion.  This is not worth worrying about
+ * if it only happens, say, once per PL/Tcl function call.  If it does seem
+ * worth worrying about, use the wrapper macros.
+ */
+
+static inline char *
+utf_u2e(const char *src)
+{
+	return pg_any_to_server(src, strlen(src), PG_UTF8);
+}
+
+static inline char *
+utf_e2u(const char *src)
+{
+	return pg_server_to_any(src, strlen(src), PG_UTF8);
+}
+
+#define UTF_BEGIN \
+	do { \
+		const char *_pltcl_utf_src = NULL; \
+		char *_pltcl_utf_dst = NULL
+
+#define UTF_END \
+	if (_pltcl_utf_src != (const char *) _pltcl_utf_dst) \
+			pfree(_pltcl_utf_dst); \
+	} while (0)
+
+#define UTF_U2E(x) \
+	(_pltcl_utf_dst = utf_u2e(_pltcl_utf_src = (x)))
+
+#define UTF_E2U(x) \
+	(_pltcl_utf_dst = utf_e2u(_pltcl_utf_src = (x)))
+
+
+/**********************************************************************
+ * Information associated with a Tcl interpreter.  We have one interpreter
+ * that is used for all pltclu (untrusted) functions.  For pltcl (trusted)
+ * functions, there is a separate interpreter for each effective SQL userid.
+ * (This is needed to ensure that an unprivileged user can't inject Tcl code
+ * that'll be executed with the privileges of some other SQL user.)
+ *
+ * The pltcl_interp_desc structs are kept in a Postgres hash table indexed
+ * by userid OID, with OID 0 used for the single untrusted interpreter.
+ **********************************************************************/
+typedef struct pltcl_interp_desc
+{
+	Oid			user_id;		/* Hash key (must be first!) */
+	Tcl_Interp *interp;			/* The interpreter */
+	Tcl_HashTable query_hash;	/* pltcl_query_desc structs */
+} pltcl_interp_desc;
+
+
+/**********************************************************************
+ * The information we cache about loaded procedures
+ *
+ * The pltcl_proc_desc struct itself, as well as all subsidiary data,
+ * is stored in the memory context identified by the fn_cxt field.
+ * We can reclaim all the data by deleting that context, and should do so
+ * when the fn_refcount goes to zero.  (But note that we do not bother
+ * trying to clean up Tcl's copy of the procedure definition: it's Tcl's
+ * problem to manage its memory when we replace a proc definition.  We do
+ * not clean up pltcl_proc_descs when a pg_proc row is deleted, only when
+ * it is updated, and the same policy applies to Tcl's copy as well.)
+ *
+ * Note that the data in this struct is shared across all active calls;
+ * nothing except the fn_refcount should be changed by a call instance.
+ **********************************************************************/
+typedef struct pltcl_proc_desc
+{
+	char	   *user_proname;	/* user's name (from pg_proc.proname) */
+	char	   *internal_proname;	/* Tcl name (based on function OID) */
+	MemoryContext fn_cxt;		/* memory context for this procedure */
+	unsigned long fn_refcount;	/* number of active references */
+	TransactionId fn_xmin;		/* xmin of pg_proc row */
+	ItemPointerData fn_tid;		/* TID of pg_proc row */
+	bool		fn_readonly;	/* is function readonly? */
+	bool		lanpltrusted;	/* is it pltcl (vs. pltclu)? */
+	pltcl_interp_desc *interp_desc; /* interpreter to use */
+	Oid			result_typid;	/* OID of fn's result type */
+	FmgrInfo	result_in_func; /* input function for fn's result type */
+	Oid			result_typioparam;	/* param to pass to same */
+	bool		fn_retisset;	/* true if function returns a set */
+	bool		fn_retistuple;	/* true if function returns composite */
+	bool		fn_retisdomain; /* true if function returns domain */
+	void	   *domain_info;	/* opaque cache for domain checks */
+	int			nargs;			/* number of arguments */
+	/* these arrays have nargs entries: */
+	FmgrInfo   *arg_out_func;	/* output fns for arg types */
+	bool	   *arg_is_rowtype; /* is each arg composite? */
+} pltcl_proc_desc;
+
+
+/**********************************************************************
+ * The information we cache about prepared and saved plans
+ **********************************************************************/
+typedef struct pltcl_query_desc
+{
+	char		qname[20];
+	SPIPlanPtr	plan;
+	int			nargs;
+	Oid		   *argtypes;
+	FmgrInfo   *arginfuncs;
+	Oid		   *argtypioparams;
+} pltcl_query_desc;
+
+
+/**********************************************************************
+ * For speedy lookup, we maintain a hash table mapping from
+ * function OID + trigger flag + user OID to pltcl_proc_desc pointers.
+ * The reason the pltcl_proc_desc struct isn't directly part of the hash
+ * entry is to simplify recovery from errors during compile_pltcl_function.
+ *
+ * Note: if the same function is called by multiple userIDs within a session,
+ * there will be a separate pltcl_proc_desc entry for each userID in the case
+ * of pltcl functions, but only one entry for pltclu functions, because we
+ * set user_id = 0 for that case.
+ **********************************************************************/
+typedef struct pltcl_proc_key
+{
+	Oid			proc_id;		/* Function OID */
+
+	/*
+	 * is_trigger is really a bool, but declare as Oid to ensure this struct
+	 * contains no padding
+	 */
+	Oid			is_trigger;		/* is it a trigger function? */
+	Oid			user_id;		/* User calling the function, or 0 */
+} pltcl_proc_key;
+
+typedef struct pltcl_proc_ptr
+{
+	pltcl_proc_key proc_key;	/* Hash key (must be first!) */
+	pltcl_proc_desc *proc_ptr;
+} pltcl_proc_ptr;
+
+
+/**********************************************************************
+ * Per-call state
+ **********************************************************************/
+typedef struct pltcl_call_state
+{
+	/* Call info struct, or NULL in a trigger */
+	FunctionCallInfo fcinfo;
+
+	/* Trigger data, if we're in a normal (not event) trigger; else NULL */
+	TriggerData *trigdata;
+
+	/* Function we're executing (NULL if not yet identified) */
+	pltcl_proc_desc *prodesc;
+
+	/*
+	 * Information for SRFs and functions returning composite types.
+	 * ret_tupdesc and attinmeta are set up if either fn_retistuple or
+	 * fn_retisset, since even a scalar-returning SRF needs a tuplestore.
+	 */
+	TupleDesc	ret_tupdesc;	/* return rowtype, if retistuple or retisset */
+	AttInMetadata *attinmeta;	/* metadata for building tuples of that type */
+
+	ReturnSetInfo *rsi;			/* passed-in ReturnSetInfo, if any */
+	Tuplestorestate *tuple_store;	/* SRFs accumulate result here */
+	MemoryContext tuple_store_cxt;	/* context and resowner for tuplestore */
+	ResourceOwner tuple_store_owner;
+} pltcl_call_state;
+
+
+/**********************************************************************
+ * Global data
+ **********************************************************************/
+static char *pltcl_start_proc = NULL;
+static char *pltclu_start_proc = NULL;
+static bool pltcl_pm_init_done = false;
+static Tcl_Interp *pltcl_hold_interp = NULL;
+static HTAB *pltcl_interp_htab = NULL;
+static HTAB *pltcl_proc_htab = NULL;
+
+/* this is saved and restored by pltcl_handler */
+static pltcl_call_state *pltcl_current_call_state = NULL;
+
+/**********************************************************************
+ * Lookup table for SQLSTATE condition names
+ **********************************************************************/
+typedef struct
+{
+	const char *label;
+	int			sqlerrstate;
+} TclExceptionNameMap;
+
+static const TclExceptionNameMap exception_name_map[] = {
+#include "pltclerrcodes.h"		/* pgrminclude ignore */
+	{NULL, 0}
+};
+
+/**********************************************************************
+ * Forward declarations
+ **********************************************************************/
+void		_PG_init(void);
+
+static void pltcl_init_interp(pltcl_interp_desc *interp_desc,
+							  Oid prolang, bool pltrusted);
+static pltcl_interp_desc *pltcl_fetch_interp(Oid prolang, bool pltrusted);
+static void call_pltcl_start_proc(Oid prolang, bool pltrusted);
+static void start_proc_error_callback(void *arg);
+
+static Datum pltcl_handler(PG_FUNCTION_ARGS, bool pltrusted);
+
+static Datum pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
+								bool pltrusted);
+static HeapTuple pltcl_trigger_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
+									   bool pltrusted);
+static void pltcl_event_trigger_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
+										bool pltrusted);
+
+static void throw_tcl_error(Tcl_Interp *interp, const char *proname);
+
+static pltcl_proc_desc *compile_pltcl_function(Oid fn_oid, Oid tgreloid,
+											   bool is_event_trigger,
+											   bool pltrusted);
+
+static int	pltcl_elog(ClientData cdata, Tcl_Interp *interp,
+					   int objc, Tcl_Obj *const objv[]);
+static void pltcl_construct_errorCode(Tcl_Interp *interp, ErrorData *edata);
+static const char *pltcl_get_condition_name(int sqlstate);
+static int	pltcl_quote(ClientData cdata, Tcl_Interp *interp,
+						int objc, Tcl_Obj *const objv[]);
+static int	pltcl_argisnull(ClientData cdata, Tcl_Interp *interp,
+							int objc, Tcl_Obj *const objv[]);
+static int	pltcl_returnnull(ClientData cdata, Tcl_Interp *interp,
+							 int objc, Tcl_Obj *const objv[]);
+static int	pltcl_returnnext(ClientData cdata, Tcl_Interp *interp,
+							 int objc, Tcl_Obj *const objv[]);
+static int	pltcl_SPI_execute(ClientData cdata, Tcl_Interp *interp,
+							  int objc, Tcl_Obj *const objv[]);
+static int	pltcl_process_SPI_result(Tcl_Interp *interp,
+									 const char *arrayname,
+									 Tcl_Obj *loop_body,
+									 int spi_rc,
+									 SPITupleTable *tuptable,
+									 uint64 ntuples);
+static int	pltcl_SPI_prepare(ClientData cdata, Tcl_Interp *interp,
+							  int objc, Tcl_Obj *const objv[]);
+static int	pltcl_SPI_execute_plan(ClientData cdata, Tcl_Interp *interp,
+								   int objc, Tcl_Obj *const objv[]);
+static int	pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
+								 int objc, Tcl_Obj *const objv[]);
+static int	pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+						 int objc, Tcl_Obj *const objv[]);
+static int	pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+						   int objc, Tcl_Obj *const objv[]);
+
+static void pltcl_subtrans_begin(MemoryContext oldcontext,
+								 ResourceOwner oldowner);
+static void pltcl_subtrans_commit(MemoryContext oldcontext,
+								  ResourceOwner oldowner);
+static void pltcl_subtrans_abort(Tcl_Interp *interp,
+								 MemoryContext oldcontext,
+								 ResourceOwner oldowner);
+
+static void pltcl_set_tuple_values(Tcl_Interp *interp, const char *arrayname,
+								   uint64 tupno, HeapTuple tuple, TupleDesc tupdesc);
+static Tcl_Obj *pltcl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc, bool include_generated);
+static HeapTuple pltcl_build_tuple_result(Tcl_Interp *interp,
+										  Tcl_Obj **kvObjv, int kvObjc,
+										  pltcl_call_state *call_state);
+static void pltcl_init_tuple_store(pltcl_call_state *call_state);
+
+
+/*
+ * Hack to override Tcl's builtin Notifier subsystem.  This prevents the
+ * backend from becoming multithreaded, which breaks all sorts of things.
+ * That happens in the default version of Tcl_InitNotifier if the TCL library
+ * has been compiled with multithreading support (i.e. when TCL_THREADS is
+ * defined under Unix, and in all cases under Windows).
+ * It's okay to disable the notifier because we never enter the Tcl event loop
+ * from Postgres, so the notifier capabilities are initialized, but never
+ * used.  Only InitNotifier and DeleteFileHandler ever seem to get called
+ * within Postgres, but we implement all the functions for completeness.
+ */
+static ClientData
+pltcl_InitNotifier(void)
+{
+	static int	fakeThreadKey;	/* To give valid address for ClientData */
+
+	return (ClientData) &(fakeThreadKey);
+}
+
+static void
+pltcl_FinalizeNotifier(ClientData clientData)
+{
+}
+
+static void
+pltcl_SetTimer(CONST86 Tcl_Time *timePtr)
+{
+}
+
+static void
+pltcl_AlertNotifier(ClientData clientData)
+{
+}
+
+static void
+pltcl_CreateFileHandler(int fd, int mask,
+						Tcl_FileProc *proc, ClientData clientData)
+{
+}
+
+static void
+pltcl_DeleteFileHandler(int fd)
+{
+}
+
+static void
+pltcl_ServiceModeHook(int mode)
+{
+}
+
+static int
+pltcl_WaitForEvent(CONST86 Tcl_Time *timePtr)
+{
+	return 0;
+}
+
+
+/*
+ * _PG_init()			- library load-time initialization
+ *
+ * DO NOT make this static nor change its name!
+ *
+ * The work done here must be safe to do in the postmaster process,
+ * in case the pltcl library is preloaded in the postmaster.
+ */
+void
+_PG_init(void)
+{
+	Tcl_NotifierProcs notifier;
+	HASHCTL		hash_ctl;
+
+	/* Be sure we do initialization only once (should be redundant now) */
+	if (pltcl_pm_init_done)
+		return;
+
+	pg_bindtextdomain(TEXTDOMAIN);
+
+#ifdef WIN32
+	/* Required on win32 to prevent error loading init.tcl */
+	Tcl_FindExecutable("");
+#endif
+
+	/*
+	 * Override the functions in the Notifier subsystem.  See comments above.
+	 */
+	notifier.setTimerProc = pltcl_SetTimer;
+	notifier.waitForEventProc = pltcl_WaitForEvent;
+	notifier.createFileHandlerProc = pltcl_CreateFileHandler;
+	notifier.deleteFileHandlerProc = pltcl_DeleteFileHandler;
+	notifier.initNotifierProc = pltcl_InitNotifier;
+	notifier.finalizeNotifierProc = pltcl_FinalizeNotifier;
+	notifier.alertNotifierProc = pltcl_AlertNotifier;
+	notifier.serviceModeHookProc = pltcl_ServiceModeHook;
+	Tcl_SetNotifier(&notifier);
+
+	/************************************************************
+	 * Create the dummy hold interpreter to prevent close of
+	 * stdout and stderr on DeleteInterp
+	 ************************************************************/
+	if ((pltcl_hold_interp = Tcl_CreateInterp()) == NULL)
+		elog(ERROR, "could not create dummy Tcl interpreter");
+	if (Tcl_Init(pltcl_hold_interp) == TCL_ERROR)
+		elog(ERROR, "could not initialize dummy Tcl interpreter");
+
+	/************************************************************
+	 * Create the hash table for working interpreters
+	 ************************************************************/
+	hash_ctl.keysize = sizeof(Oid);
+	hash_ctl.entrysize = sizeof(pltcl_interp_desc);
+	pltcl_interp_htab = hash_create("PL/Tcl interpreters",
+									8,
+									&hash_ctl,
+									HASH_ELEM | HASH_BLOBS);
+
+	/************************************************************
+	 * Create the hash table for function lookup
+	 ************************************************************/
+	hash_ctl.keysize = sizeof(pltcl_proc_key);
+	hash_ctl.entrysize = sizeof(pltcl_proc_ptr);
+	pltcl_proc_htab = hash_create("PL/Tcl functions",
+								  100,
+								  &hash_ctl,
+								  HASH_ELEM | HASH_BLOBS);
+
+	/************************************************************
+	 * Define PL/Tcl's custom GUCs
+	 ************************************************************/
+	DefineCustomStringVariable("pltcl.start_proc",
+							   gettext_noop("PL/Tcl function to call once when pltcl is first used."),
+							   NULL,
+							   &pltcl_start_proc,
+							   NULL,
+							   PGC_SUSET, 0,
+							   NULL, NULL, NULL);
+	DefineCustomStringVariable("pltclu.start_proc",
+							   gettext_noop("PL/TclU function to call once when pltclu is first used."),
+							   NULL,
+							   &pltclu_start_proc,
+							   NULL,
+							   PGC_SUSET, 0,
+							   NULL, NULL, NULL);
+
+	MarkGUCPrefixReserved("pltcl");
+	MarkGUCPrefixReserved("pltclu");
+
+	pltcl_pm_init_done = true;
+}
+
+/**********************************************************************
+ * pltcl_init_interp() - initialize a new Tcl interpreter
+ **********************************************************************/
+static void
+pltcl_init_interp(pltcl_interp_desc *interp_desc, Oid prolang, bool pltrusted)
+{
+	Tcl_Interp *interp;
+	char		interpname[32];
+
+	/************************************************************
+	 * Create the Tcl interpreter subsidiary to pltcl_hold_interp.
+	 * Note: Tcl automatically does Tcl_Init in the untrusted case,
+	 * and it's not wanted in the trusted case.
+	 ************************************************************/
+	snprintf(interpname, sizeof(interpname), "subsidiary_%u", interp_desc->user_id);
+	if ((interp = Tcl_CreateSlave(pltcl_hold_interp, interpname,
+								  pltrusted ? 1 : 0)) == NULL)
+		elog(ERROR, "could not create subsidiary Tcl interpreter");
+
+	/************************************************************
+	 * Initialize the query hash table associated with interpreter
+	 ************************************************************/
+	Tcl_InitHashTable(&interp_desc->query_hash, TCL_STRING_KEYS);
+
+	/************************************************************
+	 * Install the commands for SPI support in the interpreter
+	 ************************************************************/
+	Tcl_CreateObjCommand(interp, "elog",
+						 pltcl_elog, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "quote",
+						 pltcl_quote, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "argisnull",
+						 pltcl_argisnull, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "return_null",
+						 pltcl_returnnull, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "return_next",
+						 pltcl_returnnext, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "spi_exec",
+						 pltcl_SPI_execute, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "spi_prepare",
+						 pltcl_SPI_prepare, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "spi_execp",
+						 pltcl_SPI_execute_plan, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "subtransaction",
+						 pltcl_subtransaction, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "commit",
+						 pltcl_commit, NULL, NULL);
+	Tcl_CreateObjCommand(interp, "rollback",
+						 pltcl_rollback, NULL, NULL);
+
+	/************************************************************
+	 * Call the appropriate start_proc, if there is one.
+	 *
+	 * We must set interp_desc->interp before the call, else the start_proc
+	 * won't find the interpreter it's supposed to use.  But, if the
+	 * start_proc fails, we want to abandon use of the interpreter.
+	 ************************************************************/
+	PG_TRY();
+	{
+		interp_desc->interp = interp;
+		call_pltcl_start_proc(prolang, pltrusted);
+	}
+	PG_CATCH();
+	{
+		interp_desc->interp = NULL;
+		Tcl_DeleteInterp(interp);
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+}
+
+/**********************************************************************
+ * pltcl_fetch_interp() - fetch the Tcl interpreter to use for a function
+ *
+ * This also takes care of any on-first-use initialization required.
+ **********************************************************************/
+static pltcl_interp_desc *
+pltcl_fetch_interp(Oid prolang, bool pltrusted)
+{
+	Oid			user_id;
+	pltcl_interp_desc *interp_desc;
+	bool		found;
+
+	/* Find or create the interpreter hashtable entry for this userid */
+	if (pltrusted)
+		user_id = GetUserId();
+	else
+		user_id = InvalidOid;
+
+	interp_desc = hash_search(pltcl_interp_htab, &user_id,
+							  HASH_ENTER,
+							  &found);
+	if (!found)
+		interp_desc->interp = NULL;
+
+	/* If we haven't yet successfully made an interpreter, try to do that */
+	if (!interp_desc->interp)
+		pltcl_init_interp(interp_desc, prolang, pltrusted);
+
+	return interp_desc;
+}
+
+
+/**********************************************************************
+ * call_pltcl_start_proc()	 - Call user-defined initialization proc, if any
+ **********************************************************************/
+static void
+call_pltcl_start_proc(Oid prolang, bool pltrusted)
+{
+	LOCAL_FCINFO(fcinfo, 0);
+	char	   *start_proc;
+	const char *gucname;
+	ErrorContextCallback errcallback;
+	List	   *namelist;
+	Oid			procOid;
+	HeapTuple	procTup;
+	Form_pg_proc procStruct;
+	AclResult	aclresult;
+	FmgrInfo	finfo;
+	PgStat_FunctionCallUsage fcusage;
+
+	/* select appropriate GUC */
+	start_proc = pltrusted ? pltcl_start_proc : pltclu_start_proc;
+	gucname = pltrusted ? "pltcl.start_proc" : "pltclu.start_proc";
+
+	/* Nothing to do if it's empty or unset */
+	if (start_proc == NULL || start_proc[0] == '\0')
+		return;
+
+	/* Set up errcontext callback to make errors more helpful */
+	errcallback.callback = start_proc_error_callback;
+	errcallback.arg = unconstify(char *, gucname);
+	errcallback.previous = error_context_stack;
+	error_context_stack = &errcallback;
+
+	/* Parse possibly-qualified identifier and look up the function */
+	namelist = stringToQualifiedNameList(start_proc);
+	procOid = LookupFuncName(namelist, 0, NULL, false);
+
+	/* Current user must have permission to call function */
+	aclresult = pg_proc_aclcheck(procOid, GetUserId(), ACL_EXECUTE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, OBJECT_FUNCTION, start_proc);
+
+	/* Get the function's pg_proc entry */
+	procTup = SearchSysCache1(PROCOID, ObjectIdGetDatum(procOid));
+	if (!HeapTupleIsValid(procTup))
+		elog(ERROR, "cache lookup failed for function %u", procOid);
+	procStruct = (Form_pg_proc) GETSTRUCT(procTup);
+
+	/* It must be same language as the function we're currently calling */
+	if (procStruct->prolang != prolang)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("function \"%s\" is in the wrong language",
+						start_proc)));
+
+	/*
+	 * It must not be SECURITY DEFINER, either.  This together with the
+	 * language match check ensures that the function will execute in the same
+	 * Tcl interpreter we just finished initializing.
+	 */
+	if (procStruct->prosecdef)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("function \"%s\" must not be SECURITY DEFINER",
+						start_proc)));
+
+	/* A-OK */
+	ReleaseSysCache(procTup);
+
+	/*
+	 * Call the function using the normal SQL function call mechanism.  We
+	 * could perhaps cheat and jump directly to pltcl_handler(), but it seems
+	 * better to do it this way so that the call is exposed to, eg, call
+	 * statistics collection.
+	 */
+	InvokeFunctionExecuteHook(procOid);
+	fmgr_info(procOid, &finfo);
+	InitFunctionCallInfoData(*fcinfo, &finfo,
+							 0,
+							 InvalidOid, NULL, NULL);
+	pgstat_init_function_usage(fcinfo, &fcusage);
+	(void) FunctionCallInvoke(fcinfo);
+	pgstat_end_function_usage(&fcusage, true);
+
+	/* Pop the error context stack */
+	error_context_stack = errcallback.previous;
+}
+
+/*
+ * Error context callback for errors occurring during start_proc processing.
+ */
+static void
+start_proc_error_callback(void *arg)
+{
+	const char *gucname = (const char *) arg;
+
+	/* translator: %s is "pltcl.start_proc" or "pltclu.start_proc" */
+	errcontext("processing %s parameter", gucname);
+}
+
+
+/**********************************************************************
+ * pltcl_call_handler		- This is the only visible function
+ *				  of the PL interpreter. The PostgreSQL
+ *				  function manager and trigger manager
+ *				  call this function for execution of
+ *				  PL/Tcl procedures.
+ **********************************************************************/
+PG_FUNCTION_INFO_V1(pltcl_call_handler);
+
+/* keep non-static */
+Datum
+pltcl_call_handler(PG_FUNCTION_ARGS)
+{
+	return pltcl_handler(fcinfo, true);
+}
+
+/*
+ * Alternative handler for unsafe functions
+ */
+PG_FUNCTION_INFO_V1(pltclu_call_handler);
+
+/* keep non-static */
+Datum
+pltclu_call_handler(PG_FUNCTION_ARGS)
+{
+	return pltcl_handler(fcinfo, false);
+}
+
+
+/**********************************************************************
+ * pltcl_handler()		- Handler for function and trigger calls, for
+ *						  both trusted and untrusted interpreters.
+ **********************************************************************/
+static Datum
+pltcl_handler(PG_FUNCTION_ARGS, bool pltrusted)
+{
+	Datum		retval = (Datum) 0;
+	pltcl_call_state current_call_state;
+	pltcl_call_state *save_call_state;
+
+	/*
+	 * Initialize current_call_state to nulls/zeroes; in particular, set its
+	 * prodesc pointer to null.  Anything that sets it non-null should
+	 * increase the prodesc's fn_refcount at the same time.  We'll decrease
+	 * the refcount, and then delete the prodesc if it's no longer referenced,
+	 * on the way out of this function.  This ensures that prodescs live as
+	 * long as needed even if somebody replaces the originating pg_proc row
+	 * while they're executing.
+	 */
+	memset(&current_call_state, 0, sizeof(current_call_state));
+
+	/*
+	 * Ensure that static pointer is saved/restored properly
+	 */
+	save_call_state = pltcl_current_call_state;
+	pltcl_current_call_state = &current_call_state;
+
+	PG_TRY();
+	{
+		/*
+		 * Determine if called as function or trigger and call appropriate
+		 * subhandler
+		 */
+		if (CALLED_AS_TRIGGER(fcinfo))
+		{
+			/* invoke the trigger handler */
+			retval = PointerGetDatum(pltcl_trigger_handler(fcinfo,
+														   &current_call_state,
+														   pltrusted));
+		}
+		else if (CALLED_AS_EVENT_TRIGGER(fcinfo))
+		{
+			/* invoke the event trigger handler */
+			pltcl_event_trigger_handler(fcinfo, &current_call_state, pltrusted);
+			retval = (Datum) 0;
+		}
+		else
+		{
+			/* invoke the regular function handler */
+			current_call_state.fcinfo = fcinfo;
+			retval = pltcl_func_handler(fcinfo, &current_call_state, pltrusted);
+		}
+	}
+	PG_FINALLY();
+	{
+		/* Restore static pointer, then clean up the prodesc refcount if any */
+		/*
+		 * (We're being paranoid in case an error is thrown in context
+		 * deletion)
+		 */
+		pltcl_current_call_state = save_call_state;
+		if (current_call_state.prodesc != NULL)
+		{
+			Assert(current_call_state.prodesc->fn_refcount > 0);
+			if (--current_call_state.prodesc->fn_refcount == 0)
+				MemoryContextDelete(current_call_state.prodesc->fn_cxt);
+		}
+	}
+	PG_END_TRY();
+
+	return retval;
+}
+
+
+/**********************************************************************
+ * pltcl_func_handler()		- Handler for regular function calls
+ **********************************************************************/
+static Datum
+pltcl_func_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
+				   bool pltrusted)
+{
+	bool		nonatomic;
+	pltcl_proc_desc *prodesc;
+	Tcl_Interp *volatile interp;
+	Tcl_Obj    *tcl_cmd;
+	int			i;
+	int			tcl_rc;
+	Datum		retval;
+
+	nonatomic = fcinfo->context &&
+		IsA(fcinfo->context, CallContext) &&
+		!castNode(CallContext, fcinfo->context)->atomic;
+
+	/* Connect to SPI manager */
+	if (SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0) != SPI_OK_CONNECT)
+		elog(ERROR, "could not connect to SPI manager");
+
+	/* Find or compile the function */
+	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid, InvalidOid,
+									 false, pltrusted);
+
+	call_state->prodesc = prodesc;
+	prodesc->fn_refcount++;
+
+	interp = prodesc->interp_desc->interp;
+
+	/*
+	 * If we're a SRF, check caller can handle materialize mode, and save
+	 * relevant info into call_state.  We must ensure that the returned
+	 * tuplestore is owned by the caller's context, even if we first create it
+	 * inside a subtransaction.
+	 */
+	if (prodesc->fn_retisset)
+	{
+		ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
+
+		if (!rsi || !IsA(rsi, ReturnSetInfo))
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("set-valued function called in context that cannot accept a set")));
+
+		if (!(rsi->allowedModes & SFRM_Materialize))
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("materialize mode required, but it is not allowed in this context")));
+
+		call_state->rsi = rsi;
+		call_state->tuple_store_cxt = rsi->econtext->ecxt_per_query_memory;
+		call_state->tuple_store_owner = CurrentResourceOwner;
+	}
+
+	/************************************************************
+	 * Create the tcl command to call the internal
+	 * proc in the Tcl interpreter
+	 ************************************************************/
+	tcl_cmd = Tcl_NewObj();
+	Tcl_ListObjAppendElement(NULL, tcl_cmd,
+							 Tcl_NewStringObj(prodesc->internal_proname, -1));
+
+	/* We hold a refcount on tcl_cmd just to be sure it stays around */
+	Tcl_IncrRefCount(tcl_cmd);
+
+	/************************************************************
+	 * Add all call arguments to the command
+	 ************************************************************/
+	PG_TRY();
+	{
+		for (i = 0; i < prodesc->nargs; i++)
+		{
+			if (prodesc->arg_is_rowtype[i])
+			{
+				/**************************************************
+				 * For tuple values, add a list for 'array set ...'
+				 **************************************************/
+				if (fcinfo->args[i].isnull)
+					Tcl_ListObjAppendElement(NULL, tcl_cmd, Tcl_NewObj());
+				else
+				{
+					HeapTupleHeader td;
+					Oid			tupType;
+					int32		tupTypmod;
+					TupleDesc	tupdesc;
+					HeapTupleData tmptup;
+					Tcl_Obj    *list_tmp;
+
+					td = DatumGetHeapTupleHeader(fcinfo->args[i].value);
+					/* Extract rowtype info and find a tupdesc */
+					tupType = HeapTupleHeaderGetTypeId(td);
+					tupTypmod = HeapTupleHeaderGetTypMod(td);
+					tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
+					/* Build a temporary HeapTuple control structure */
+					tmptup.t_len = HeapTupleHeaderGetDatumLength(td);
+					tmptup.t_data = td;
+
+					list_tmp = pltcl_build_tuple_argument(&tmptup, tupdesc, true);
+					Tcl_ListObjAppendElement(NULL, tcl_cmd, list_tmp);
+
+					ReleaseTupleDesc(tupdesc);
+				}
+			}
+			else
+			{
+				/**************************************************
+				 * Single values are added as string element
+				 * of their external representation
+				 **************************************************/
+				if (fcinfo->args[i].isnull)
+					Tcl_ListObjAppendElement(NULL, tcl_cmd, Tcl_NewObj());
+				else
+				{
+					char	   *tmp;
+
+					tmp = OutputFunctionCall(&prodesc->arg_out_func[i],
+											 fcinfo->args[i].value);
+					UTF_BEGIN;
+					Tcl_ListObjAppendElement(NULL, tcl_cmd,
+											 Tcl_NewStringObj(UTF_E2U(tmp), -1));
+					UTF_END;
+					pfree(tmp);
+				}
+			}
+		}
+	}
+	PG_CATCH();
+	{
+		/* Release refcount to free tcl_cmd */
+		Tcl_DecrRefCount(tcl_cmd);
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	/************************************************************
+	 * Call the Tcl function
+	 *
+	 * We assume no PG error can be thrown directly from this call.
+	 ************************************************************/
+	tcl_rc = Tcl_EvalObjEx(interp, tcl_cmd, (TCL_EVAL_DIRECT | TCL_EVAL_GLOBAL));
+
+	/* Release refcount to free tcl_cmd (and all subsidiary objects) */
+	Tcl_DecrRefCount(tcl_cmd);
+
+	/************************************************************
+	 * Check for errors reported by Tcl.
+	 ************************************************************/
+	if (tcl_rc != TCL_OK)
+		throw_tcl_error(interp, prodesc->user_proname);
+
+	/************************************************************
+	 * Disconnect from SPI manager and then create the return
+	 * value datum (if the input function does a palloc for it
+	 * this must not be allocated in the SPI memory context
+	 * because SPI_finish would free it).  But don't try to call
+	 * the result_in_func if we've been told to return a NULL;
+	 * the Tcl result may not be a valid value of the result type
+	 * in that case.
+	 ************************************************************/
+	if (SPI_finish() != SPI_OK_FINISH)
+		elog(ERROR, "SPI_finish() failed");
+
+	if (prodesc->fn_retisset)
+	{
+		ReturnSetInfo *rsi = call_state->rsi;
+
+		/* We already checked this is OK */
+		rsi->returnMode = SFRM_Materialize;
+
+		/* If we produced any tuples, send back the result */
+		if (call_state->tuple_store)
+		{
+			rsi->setResult = call_state->tuple_store;
+			if (call_state->ret_tupdesc)
+			{
+				MemoryContext oldcxt;
+
+				oldcxt = MemoryContextSwitchTo(call_state->tuple_store_cxt);
+				rsi->setDesc = CreateTupleDescCopy(call_state->ret_tupdesc);
+				MemoryContextSwitchTo(oldcxt);
+			}
+		}
+		retval = (Datum) 0;
+		fcinfo->isnull = true;
+	}
+	else if (fcinfo->isnull)
+	{
+		retval = InputFunctionCall(&prodesc->result_in_func,
+								   NULL,
+								   prodesc->result_typioparam,
+								   -1);
+	}
+	else if (prodesc->fn_retistuple)
+	{
+		TupleDesc	td;
+		HeapTuple	tup;
+		Tcl_Obj    *resultObj;
+		Tcl_Obj   **resultObjv;
+		int			resultObjc;
+
+		/*
+		 * Set up data about result type.  XXX it's tempting to consider
+		 * caching this in the prodesc, in the common case where the rowtype
+		 * is determined by the function not the calling query.  But we'd have
+		 * to be able to deal with ADD/DROP/ALTER COLUMN events when the
+		 * result type is a named composite type, so it's not exactly trivial.
+		 * Maybe worth improving someday.
+		 */
+		switch (get_call_result_type(fcinfo, NULL, &td))
+		{
+			case TYPEFUNC_COMPOSITE:
+				/* success */
+				break;
+			case TYPEFUNC_COMPOSITE_DOMAIN:
+				Assert(prodesc->fn_retisdomain);
+				break;
+			case TYPEFUNC_RECORD:
+				/* failed to determine actual type of RECORD */
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("function returning record called in context "
+								"that cannot accept type record")));
+				break;
+			default:
+				/* result type isn't composite? */
+				elog(ERROR, "return type must be a row type");
+				break;
+		}
+
+		Assert(!call_state->ret_tupdesc);
+		Assert(!call_state->attinmeta);
+		call_state->ret_tupdesc = td;
+		call_state->attinmeta = TupleDescGetAttInMetadata(td);
+
+		/* Convert function result to tuple */
+		resultObj = Tcl_GetObjResult(interp);
+		if (Tcl_ListObjGetElements(interp, resultObj, &resultObjc, &resultObjv) == TCL_ERROR)
+			throw_tcl_error(interp, prodesc->user_proname);
+
+		tup = pltcl_build_tuple_result(interp, resultObjv, resultObjc,
+									   call_state);
+		retval = HeapTupleGetDatum(tup);
+	}
+	else
+		retval = InputFunctionCall(&prodesc->result_in_func,
+								   utf_u2e(Tcl_GetStringResult(interp)),
+								   prodesc->result_typioparam,
+								   -1);
+
+	return retval;
+}
+
+
+/**********************************************************************
+ * pltcl_trigger_handler()	- Handler for trigger calls
+ **********************************************************************/
+static HeapTuple
+pltcl_trigger_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
+					  bool pltrusted)
+{
+	pltcl_proc_desc *prodesc;
+	Tcl_Interp *volatile interp;
+	TriggerData *trigdata = (TriggerData *) fcinfo->context;
+	char	   *stroid;
+	TupleDesc	tupdesc;
+	volatile HeapTuple rettup;
+	Tcl_Obj    *tcl_cmd;
+	Tcl_Obj    *tcl_trigtup;
+	int			tcl_rc;
+	int			i;
+	const char *result;
+	int			result_Objc;
+	Tcl_Obj   **result_Objv;
+	int			rc PG_USED_FOR_ASSERTS_ONLY;
+
+	call_state->trigdata = trigdata;
+
+	/* Connect to SPI manager */
+	if (SPI_connect() != SPI_OK_CONNECT)
+		elog(ERROR, "could not connect to SPI manager");
+
+	/* Make transition tables visible to this SPI connection */
+	rc = SPI_register_trigger_data(trigdata);
+	Assert(rc >= 0);
+
+	/* Find or compile the function */
+	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid,
+									 RelationGetRelid(trigdata->tg_relation),
+									 false, /* not an event trigger */
+									 pltrusted);
+
+	call_state->prodesc = prodesc;
+	prodesc->fn_refcount++;
+
+	interp = prodesc->interp_desc->interp;
+
+	tupdesc = RelationGetDescr(trigdata->tg_relation);
+
+	/************************************************************
+	 * Create the tcl command to call the internal
+	 * proc in the interpreter
+	 ************************************************************/
+	tcl_cmd = Tcl_NewObj();
+	Tcl_IncrRefCount(tcl_cmd);
+
+	PG_TRY();
+	{
+		/* The procedure name (note this is all ASCII, so no utf_e2u) */
+		Tcl_ListObjAppendElement(NULL, tcl_cmd,
+								 Tcl_NewStringObj(prodesc->internal_proname, -1));
+
+		/* The trigger name for argument TG_name */
+		Tcl_ListObjAppendElement(NULL, tcl_cmd,
+								 Tcl_NewStringObj(utf_e2u(trigdata->tg_trigger->tgname), -1));
+
+		/* The oid of the trigger relation for argument TG_relid */
+		/* Consider not converting to a string for more performance? */
+		stroid = DatumGetCString(DirectFunctionCall1(oidout,
+													 ObjectIdGetDatum(trigdata->tg_relation->rd_id)));
+		Tcl_ListObjAppendElement(NULL, tcl_cmd,
+								 Tcl_NewStringObj(stroid, -1));
+		pfree(stroid);
+
+		/* The name of the table the trigger is acting on: TG_table_name */
+		stroid = SPI_getrelname(trigdata->tg_relation);
+		Tcl_ListObjAppendElement(NULL, tcl_cmd,
+								 Tcl_NewStringObj(utf_e2u(stroid), -1));
+		pfree(stroid);
+
+		/* The schema of the table the trigger is acting on: TG_table_schema */
+		stroid = SPI_getnspname(trigdata->tg_relation);
+		Tcl_ListObjAppendElement(NULL, tcl_cmd,
+								 Tcl_NewStringObj(utf_e2u(stroid), -1));
+		pfree(stroid);
+
+		/* A list of attribute names for argument TG_relatts */
+		tcl_trigtup = Tcl_NewObj();
+		Tcl_ListObjAppendElement(NULL, tcl_trigtup, Tcl_NewObj());
+		for (i = 0; i < tupdesc->natts; i++)
+		{
+			Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+			if (att->attisdropped)
+				Tcl_ListObjAppendElement(NULL, tcl_trigtup, Tcl_NewObj());
+			else
+				Tcl_ListObjAppendElement(NULL, tcl_trigtup,
+										 Tcl_NewStringObj(utf_e2u(NameStr(att->attname)), -1));
+		}
+		Tcl_ListObjAppendElement(NULL, tcl_cmd, tcl_trigtup);
+
+		/* The when part of the event for TG_when */
+		if (TRIGGER_FIRED_BEFORE(trigdata->tg_event))
+			Tcl_ListObjAppendElement(NULL, tcl_cmd,
+									 Tcl_NewStringObj("BEFORE", -1));
+		else if (TRIGGER_FIRED_AFTER(trigdata->tg_event))
+			Tcl_ListObjAppendElement(NULL, tcl_cmd,
+									 Tcl_NewStringObj("AFTER", -1));
+		else if (TRIGGER_FIRED_INSTEAD(trigdata->tg_event))
+			Tcl_ListObjAppendElement(NULL, tcl_cmd,
+									 Tcl_NewStringObj("INSTEAD OF", -1));
+		else
+			elog(ERROR, "unrecognized WHEN tg_event: %u", trigdata->tg_event);
+
+		/* The level part of the event for TG_level */
+		if (TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
+		{
+			Tcl_ListObjAppendElement(NULL, tcl_cmd,
+									 Tcl_NewStringObj("ROW", -1));
+
+			/*
+			 * Now the command part of the event for TG_op and data for NEW
+			 * and OLD
+			 *
+			 * Note: In BEFORE trigger, stored generated columns are not
+			 * computed yet, so don't make them accessible in NEW row.
+			 */
+			if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
+			{
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 Tcl_NewStringObj("INSERT", -1));
+
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 pltcl_build_tuple_argument(trigdata->tg_trigtuple,
+																	tupdesc,
+																	!TRIGGER_FIRED_BEFORE(trigdata->tg_event)));
+				Tcl_ListObjAppendElement(NULL, tcl_cmd, Tcl_NewObj());
+
+				rettup = trigdata->tg_trigtuple;
+			}
+			else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
+			{
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 Tcl_NewStringObj("DELETE", -1));
+
+				Tcl_ListObjAppendElement(NULL, tcl_cmd, Tcl_NewObj());
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 pltcl_build_tuple_argument(trigdata->tg_trigtuple,
+																	tupdesc,
+																	true));
+
+				rettup = trigdata->tg_trigtuple;
+			}
+			else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
+			{
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 Tcl_NewStringObj("UPDATE", -1));
+
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 pltcl_build_tuple_argument(trigdata->tg_newtuple,
+																	tupdesc,
+																	!TRIGGER_FIRED_BEFORE(trigdata->tg_event)));
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 pltcl_build_tuple_argument(trigdata->tg_trigtuple,
+																	tupdesc,
+																	true));
+
+				rettup = trigdata->tg_newtuple;
+			}
+			else
+				elog(ERROR, "unrecognized OP tg_event: %u", trigdata->tg_event);
+		}
+		else if (TRIGGER_FIRED_FOR_STATEMENT(trigdata->tg_event))
+		{
+			Tcl_ListObjAppendElement(NULL, tcl_cmd,
+									 Tcl_NewStringObj("STATEMENT", -1));
+
+			if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 Tcl_NewStringObj("INSERT", -1));
+			else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 Tcl_NewStringObj("DELETE", -1));
+			else if (TRIGGER_FIRED_BY_UPDATE(trigdata->tg_event))
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 Tcl_NewStringObj("UPDATE", -1));
+			else if (TRIGGER_FIRED_BY_TRUNCATE(trigdata->tg_event))
+				Tcl_ListObjAppendElement(NULL, tcl_cmd,
+										 Tcl_NewStringObj("TRUNCATE", -1));
+			else
+				elog(ERROR, "unrecognized OP tg_event: %u", trigdata->tg_event);
+
+			Tcl_ListObjAppendElement(NULL, tcl_cmd, Tcl_NewObj());
+			Tcl_ListObjAppendElement(NULL, tcl_cmd, Tcl_NewObj());
+
+			rettup = (HeapTuple) NULL;
+		}
+		else
+			elog(ERROR, "unrecognized LEVEL tg_event: %u", trigdata->tg_event);
+
+		/* Finally append the arguments from CREATE TRIGGER */
+		for (i = 0; i < trigdata->tg_trigger->tgnargs; i++)
+			Tcl_ListObjAppendElement(NULL, tcl_cmd,
+									 Tcl_NewStringObj(utf_e2u(trigdata->tg_trigger->tgargs[i]), -1));
+	}
+	PG_CATCH();
+	{
+		Tcl_DecrRefCount(tcl_cmd);
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	/************************************************************
+	 * Call the Tcl function
+	 *
+	 * We assume no PG error can be thrown directly from this call.
+	 ************************************************************/
+	tcl_rc = Tcl_EvalObjEx(interp, tcl_cmd, (TCL_EVAL_DIRECT | TCL_EVAL_GLOBAL));
+
+	/* Release refcount to free tcl_cmd (and all subsidiary objects) */
+	Tcl_DecrRefCount(tcl_cmd);
+
+	/************************************************************
+	 * Check for errors reported by Tcl.
+	 ************************************************************/
+	if (tcl_rc != TCL_OK)
+		throw_tcl_error(interp, prodesc->user_proname);
+
+	/************************************************************
+	 * Exit SPI environment.
+	 ************************************************************/
+	if (SPI_finish() != SPI_OK_FINISH)
+		elog(ERROR, "SPI_finish() failed");
+
+	/************************************************************
+	 * The return value from the procedure might be one of
+	 * the magic strings OK or SKIP, or a list from array get.
+	 * We can check for OK or SKIP without worrying about encoding.
+	 ************************************************************/
+	result = Tcl_GetStringResult(interp);
+
+	if (strcmp(result, "OK") == 0)
+		return rettup;
+	if (strcmp(result, "SKIP") == 0)
+		return (HeapTuple) NULL;
+
+	/************************************************************
+	 * Otherwise, the return value should be a column name/value list
+	 * specifying the modified tuple to return.
+	 ************************************************************/
+	if (Tcl_ListObjGetElements(interp, Tcl_GetObjResult(interp),
+							   &result_Objc, &result_Objv) != TCL_OK)
+		ereport(ERROR,
+				(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+				 errmsg("could not split return value from trigger: %s",
+						utf_u2e(Tcl_GetStringResult(interp)))));
+
+	/* Convert function result to tuple */
+	rettup = pltcl_build_tuple_result(interp, result_Objv, result_Objc,
+									  call_state);
+
+	return rettup;
+}
+
+/**********************************************************************
+ * pltcl_event_trigger_handler()	- Handler for event trigger calls
+ **********************************************************************/
+static void
+pltcl_event_trigger_handler(PG_FUNCTION_ARGS, pltcl_call_state *call_state,
+							bool pltrusted)
+{
+	pltcl_proc_desc *prodesc;
+	Tcl_Interp *volatile interp;
+	EventTriggerData *tdata = (EventTriggerData *) fcinfo->context;
+	Tcl_Obj    *tcl_cmd;
+	int			tcl_rc;
+
+	/* Connect to SPI manager */
+	if (SPI_connect() != SPI_OK_CONNECT)
+		elog(ERROR, "could not connect to SPI manager");
+
+	/* Find or compile the function */
+	prodesc = compile_pltcl_function(fcinfo->flinfo->fn_oid,
+									 InvalidOid, true, pltrusted);
+
+	call_state->prodesc = prodesc;
+	prodesc->fn_refcount++;
+
+	interp = prodesc->interp_desc->interp;
+
+	/* Create the tcl command and call the internal proc */
+	tcl_cmd = Tcl_NewObj();
+	Tcl_IncrRefCount(tcl_cmd);
+	Tcl_ListObjAppendElement(NULL, tcl_cmd,
+							 Tcl_NewStringObj(prodesc->internal_proname, -1));
+	Tcl_ListObjAppendElement(NULL, tcl_cmd,
+							 Tcl_NewStringObj(utf_e2u(tdata->event), -1));
+	Tcl_ListObjAppendElement(NULL, tcl_cmd,
+							 Tcl_NewStringObj(utf_e2u(GetCommandTagName(tdata->tag)),
+											  -1));
+
+	tcl_rc = Tcl_EvalObjEx(interp, tcl_cmd, (TCL_EVAL_DIRECT | TCL_EVAL_GLOBAL));
+
+	/* Release refcount to free tcl_cmd (and all subsidiary objects) */
+	Tcl_DecrRefCount(tcl_cmd);
+
+	/* Check for errors reported by Tcl. */
+	if (tcl_rc != TCL_OK)
+		throw_tcl_error(interp, prodesc->user_proname);
+
+	if (SPI_finish() != SPI_OK_FINISH)
+		elog(ERROR, "SPI_finish() failed");
+}
+
+
+/**********************************************************************
+ * throw_tcl_error	- ereport an error returned from the Tcl interpreter
+ **********************************************************************/
+static void
+throw_tcl_error(Tcl_Interp *interp, const char *proname)
+{
+	/*
+	 * Caution is needed here because Tcl_GetVar could overwrite the
+	 * interpreter result (even though it's not really supposed to), and we
+	 * can't control the order of evaluation of ereport arguments. Hence, make
+	 * real sure we have our own copy of the result string before invoking
+	 * Tcl_GetVar.
+	 */
+	char	   *emsg;
+	char	   *econtext;
+
+	emsg = pstrdup(utf_u2e(Tcl_GetStringResult(interp)));
+	econtext = utf_u2e(Tcl_GetVar(interp, "errorInfo", TCL_GLOBAL_ONLY));
+	ereport(ERROR,
+			(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
+			 errmsg("%s", emsg),
+			 errcontext("%s\nin PL/Tcl function \"%s\"",
+						econtext, proname)));
+}
+
+
+/**********************************************************************
+ * compile_pltcl_function	- compile (or hopefully just look up) function
+ *
+ * tgreloid is the OID of the relation when compiling a trigger, or zero
+ * (InvalidOid) when compiling a plain function.
+ **********************************************************************/
+static pltcl_proc_desc *
+compile_pltcl_function(Oid fn_oid, Oid tgreloid,
+					   bool is_event_trigger, bool pltrusted)
+{
+	HeapTuple	procTup;
+	Form_pg_proc procStruct;
+	pltcl_proc_key proc_key;
+	pltcl_proc_ptr *proc_ptr;
+	bool		found;
+	pltcl_proc_desc *prodesc;
+	pltcl_proc_desc *old_prodesc;
+	volatile MemoryContext proc_cxt = NULL;
+	Tcl_DString proc_internal_def;
+	Tcl_DString proc_internal_body;
+
+	/* We'll need the pg_proc tuple in any case... */
+	procTup = SearchSysCache1(PROCOID, ObjectIdGetDatum(fn_oid));
+	if (!HeapTupleIsValid(procTup))
+		elog(ERROR, "cache lookup failed for function %u", fn_oid);
+	procStruct = (Form_pg_proc) GETSTRUCT(procTup);
+
+	/*
+	 * Look up function in pltcl_proc_htab; if it's not there, create an entry
+	 * and set the entry's proc_ptr to NULL.
+	 */
+	proc_key.proc_id = fn_oid;
+	proc_key.is_trigger = OidIsValid(tgreloid);
+	proc_key.user_id = pltrusted ? GetUserId() : InvalidOid;
+
+	proc_ptr = hash_search(pltcl_proc_htab, &proc_key,
+						   HASH_ENTER,
+						   &found);
+	if (!found)
+		proc_ptr->proc_ptr = NULL;
+
+	prodesc = proc_ptr->proc_ptr;
+
+	/************************************************************
+	 * If it's present, must check whether it's still up to date.
+	 * This is needed because CREATE OR REPLACE FUNCTION can modify the
+	 * function's pg_proc entry without changing its OID.
+	 ************************************************************/
+	if (prodesc != NULL &&
+		prodesc->fn_xmin == HeapTupleHeaderGetRawXmin(procTup->t_data) &&
+		ItemPointerEquals(&prodesc->fn_tid, &procTup->t_self))
+	{
+		/* It's still up-to-date, so we can use it */
+		ReleaseSysCache(procTup);
+		return prodesc;
+	}
+
+	/************************************************************
+	 * If we haven't found it in the hashtable, we analyze
+	 * the functions arguments and returntype and store
+	 * the in-/out-functions in the prodesc block and create
+	 * a new hashtable entry for it.
+	 *
+	 * Then we load the procedure into the Tcl interpreter.
+	 ************************************************************/
+	Tcl_DStringInit(&proc_internal_def);
+	Tcl_DStringInit(&proc_internal_body);
+	PG_TRY();
+	{
+		bool		is_trigger = OidIsValid(tgreloid);
+		char		internal_proname[128];
+		HeapTuple	typeTup;
+		Form_pg_type typeStruct;
+		char		proc_internal_args[33 * FUNC_MAX_ARGS];
+		Datum		prosrcdatum;
+		bool		isnull;
+		char	   *proc_source;
+		char		buf[48];
+		Tcl_Interp *interp;
+		int			i;
+		int			tcl_rc;
+		MemoryContext oldcontext;
+
+		/************************************************************
+		 * Build our internal proc name from the function's Oid.  Append
+		 * "_trigger" when appropriate to ensure the normal and trigger
+		 * cases are kept separate.  Note name must be all-ASCII.
+		 ************************************************************/
+		if (is_event_trigger)
+			snprintf(internal_proname, sizeof(internal_proname),
+					 "__PLTcl_proc_%u_evttrigger", fn_oid);
+		else if (is_trigger)
+			snprintf(internal_proname, sizeof(internal_proname),
+					 "__PLTcl_proc_%u_trigger", fn_oid);
+		else
+			snprintf(internal_proname, sizeof(internal_proname),
+					 "__PLTcl_proc_%u", fn_oid);
+
+		/************************************************************
+		 * Allocate a context that will hold all PG data for the procedure.
+		 ************************************************************/
+		proc_cxt = AllocSetContextCreate(TopMemoryContext,
+										 "PL/Tcl function",
+										 ALLOCSET_SMALL_SIZES);
+
+		/************************************************************
+		 * Allocate and fill a new procedure description block.
+		 * struct prodesc and subsidiary data must all live in proc_cxt.
+		 ************************************************************/
+		oldcontext = MemoryContextSwitchTo(proc_cxt);
+		prodesc = (pltcl_proc_desc *) palloc0(sizeof(pltcl_proc_desc));
+		prodesc->user_proname = pstrdup(NameStr(procStruct->proname));
+		MemoryContextSetIdentifier(proc_cxt, prodesc->user_proname);
+		prodesc->internal_proname = pstrdup(internal_proname);
+		prodesc->fn_cxt = proc_cxt;
+		prodesc->fn_refcount = 0;
+		prodesc->fn_xmin = HeapTupleHeaderGetRawXmin(procTup->t_data);
+		prodesc->fn_tid = procTup->t_self;
+		prodesc->nargs = procStruct->pronargs;
+		prodesc->arg_out_func = (FmgrInfo *) palloc0(prodesc->nargs * sizeof(FmgrInfo));
+		prodesc->arg_is_rowtype = (bool *) palloc0(prodesc->nargs * sizeof(bool));
+		MemoryContextSwitchTo(oldcontext);
+
+		/* Remember if function is STABLE/IMMUTABLE */
+		prodesc->fn_readonly =
+			(procStruct->provolatile != PROVOLATILE_VOLATILE);
+		/* And whether it is trusted */
+		prodesc->lanpltrusted = pltrusted;
+
+		/************************************************************
+		 * Identify the interpreter to use for the function
+		 ************************************************************/
+		prodesc->interp_desc = pltcl_fetch_interp(procStruct->prolang,
+												  prodesc->lanpltrusted);
+		interp = prodesc->interp_desc->interp;
+
+		/************************************************************
+		 * Get the required information for input conversion of the
+		 * return value.
+		 ************************************************************/
+		if (!is_trigger && !is_event_trigger)
+		{
+			Oid			rettype = procStruct->prorettype;
+
+			typeTup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(rettype));
+			if (!HeapTupleIsValid(typeTup))
+				elog(ERROR, "cache lookup failed for type %u", rettype);
+			typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
+
+			/* Disallow pseudotype result, except VOID and RECORD */
+			if (typeStruct->typtype == TYPTYPE_PSEUDO)
+			{
+				if (rettype == VOIDOID ||
+					rettype == RECORDOID)
+					 /* okay */ ;
+				else if (rettype == TRIGGEROID ||
+						 rettype == EVENT_TRIGGEROID)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("trigger functions can only be called as triggers")));
+				else
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("PL/Tcl functions cannot return type %s",
+									format_type_be(rettype))));
+			}
+
+			prodesc->result_typid = rettype;
+			fmgr_info_cxt(typeStruct->typinput,
+						  &(prodesc->result_in_func),
+						  proc_cxt);
+			prodesc->result_typioparam = getTypeIOParam(typeTup);
+
+			prodesc->fn_retisset = procStruct->proretset;
+			prodesc->fn_retistuple = type_is_rowtype(rettype);
+			prodesc->fn_retisdomain = (typeStruct->typtype == TYPTYPE_DOMAIN);
+			prodesc->domain_info = NULL;
+
+			ReleaseSysCache(typeTup);
+		}
+
+		/************************************************************
+		 * Get the required information for output conversion
+		 * of all procedure arguments, and set up argument naming info.
+		 ************************************************************/
+		if (!is_trigger && !is_event_trigger)
+		{
+			proc_internal_args[0] = '\0';
+			for (i = 0; i < prodesc->nargs; i++)
+			{
+				Oid			argtype = procStruct->proargtypes.values[i];
+
+				typeTup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(argtype));
+				if (!HeapTupleIsValid(typeTup))
+					elog(ERROR, "cache lookup failed for type %u", argtype);
+				typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
+
+				/* Disallow pseudotype argument, except RECORD */
+				if (typeStruct->typtype == TYPTYPE_PSEUDO &&
+					argtype != RECORDOID)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("PL/Tcl functions cannot accept type %s",
+									format_type_be(argtype))));
+
+				if (type_is_rowtype(argtype))
+				{
+					prodesc->arg_is_rowtype[i] = true;
+					snprintf(buf, sizeof(buf), "__PLTcl_Tup_%d", i + 1);
+				}
+				else
+				{
+					prodesc->arg_is_rowtype[i] = false;
+					fmgr_info_cxt(typeStruct->typoutput,
+								  &(prodesc->arg_out_func[i]),
+								  proc_cxt);
+					snprintf(buf, sizeof(buf), "%d", i + 1);
+				}
+
+				if (i > 0)
+					strcat(proc_internal_args, " ");
+				strcat(proc_internal_args, buf);
+
+				ReleaseSysCache(typeTup);
+			}
+		}
+		else if (is_trigger)
+		{
+			/* trigger procedure has fixed args */
+			strcpy(proc_internal_args,
+				   "TG_name TG_relid TG_table_name TG_table_schema TG_relatts TG_when TG_level TG_op __PLTcl_Tup_NEW __PLTcl_Tup_OLD args");
+		}
+		else if (is_event_trigger)
+		{
+			/* event trigger procedure has fixed args */
+			strcpy(proc_internal_args, "TG_event TG_tag");
+		}
+
+		/************************************************************
+		 * Create the tcl command to define the internal
+		 * procedure
+		 *
+		 * Leave this code as DString - performance is not critical here,
+		 * and we don't want to duplicate the knowledge of the Tcl quoting
+		 * rules that's embedded in Tcl_DStringAppendElement.
+		 ************************************************************/
+		Tcl_DStringAppendElement(&proc_internal_def, "proc");
+		Tcl_DStringAppendElement(&proc_internal_def, internal_proname);
+		Tcl_DStringAppendElement(&proc_internal_def, proc_internal_args);
+
+		/************************************************************
+		 * prefix procedure body with
+		 * upvar #0 <internal_proname> GD
+		 * and with appropriate setting of arguments
+		 ************************************************************/
+		Tcl_DStringAppend(&proc_internal_body, "upvar #0 ", -1);
+		Tcl_DStringAppend(&proc_internal_body, internal_proname, -1);
+		Tcl_DStringAppend(&proc_internal_body, " GD\n", -1);
+		if (is_trigger)
+		{
+			Tcl_DStringAppend(&proc_internal_body,
+							  "array set NEW $__PLTcl_Tup_NEW\n", -1);
+			Tcl_DStringAppend(&proc_internal_body,
+							  "array set OLD $__PLTcl_Tup_OLD\n", -1);
+			Tcl_DStringAppend(&proc_internal_body,
+							  "set i 0\n"
+							  "set v 0\n"
+							  "foreach v $args {\n"
+							  "  incr i\n"
+							  "  set $i $v\n"
+							  "}\n"
+							  "unset i v\n\n", -1);
+		}
+		else if (is_event_trigger)
+		{
+			/* no argument support for event triggers */
+		}
+		else
+		{
+			for (i = 0; i < prodesc->nargs; i++)
+			{
+				if (prodesc->arg_is_rowtype[i])
+				{
+					snprintf(buf, sizeof(buf),
+							 "array set %d $__PLTcl_Tup_%d\n",
+							 i + 1, i + 1);
+					Tcl_DStringAppend(&proc_internal_body, buf, -1);
+				}
+			}
+		}
+
+		/************************************************************
+		 * Add user's function definition to proc body
+		 ************************************************************/
+		prosrcdatum = SysCacheGetAttr(PROCOID, procTup,
+									  Anum_pg_proc_prosrc, &isnull);
+		if (isnull)
+			elog(ERROR, "null prosrc");
+		proc_source = TextDatumGetCString(prosrcdatum);
+		UTF_BEGIN;
+		Tcl_DStringAppend(&proc_internal_body, UTF_E2U(proc_source), -1);
+		UTF_END;
+		pfree(proc_source);
+		Tcl_DStringAppendElement(&proc_internal_def,
+								 Tcl_DStringValue(&proc_internal_body));
+
+		/************************************************************
+		 * Create the procedure in the interpreter
+		 ************************************************************/
+		tcl_rc = Tcl_EvalEx(interp,
+							Tcl_DStringValue(&proc_internal_def),
+							Tcl_DStringLength(&proc_internal_def),
+							TCL_EVAL_GLOBAL);
+		if (tcl_rc != TCL_OK)
+			ereport(ERROR,
+					(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
+					 errmsg("could not create internal procedure \"%s\": %s",
+							internal_proname,
+							utf_u2e(Tcl_GetStringResult(interp)))));
+	}
+	PG_CATCH();
+	{
+		/*
+		 * If we failed anywhere above, clean up whatever got allocated.  It
+		 * should all be in the proc_cxt, except for the DStrings.
+		 */
+		if (proc_cxt)
+			MemoryContextDelete(proc_cxt);
+		Tcl_DStringFree(&proc_internal_def);
+		Tcl_DStringFree(&proc_internal_body);
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
+
+	/*
+	 * Install the new proc description block in the hashtable, incrementing
+	 * its refcount (the hashtable link counts as a reference).  Then, if
+	 * there was a previous definition of the function, decrement that one's
+	 * refcount, and delete it if no longer referenced.  The order of
+	 * operations here is important: if something goes wrong during the
+	 * MemoryContextDelete, leaking some memory for the old definition is OK,
+	 * but we don't want to corrupt the live hashtable entry.  (Likewise,
+	 * freeing the DStrings is pretty low priority if that happens.)
+	 */
+	old_prodesc = proc_ptr->proc_ptr;
+
+	proc_ptr->proc_ptr = prodesc;
+	prodesc->fn_refcount++;
+
+	if (old_prodesc != NULL)
+	{
+		Assert(old_prodesc->fn_refcount > 0);
+		if (--old_prodesc->fn_refcount == 0)
+			MemoryContextDelete(old_prodesc->fn_cxt);
+	}
+
+	Tcl_DStringFree(&proc_internal_def);
+	Tcl_DStringFree(&proc_internal_body);
+
+	ReleaseSysCache(procTup);
+
+	return prodesc;
+}
+
+
+/**********************************************************************
+ * pltcl_elog()		- elog() support for PLTcl
+ **********************************************************************/
+static int
+pltcl_elog(ClientData cdata, Tcl_Interp *interp,
+		   int objc, Tcl_Obj *const objv[])
+{
+	volatile int level;
+	MemoryContext oldcontext;
+	int			priIndex;
+
+	static const char *logpriorities[] = {
+		"DEBUG", "LOG", "INFO", "NOTICE",
+		"WARNING", "ERROR", "FATAL", (const char *) NULL
+	};
+
+	static const int loglevels[] = {
+		DEBUG2, LOG, INFO, NOTICE,
+		WARNING, ERROR, FATAL
+	};
+
+	if (objc != 3)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv, "level msg");
+		return TCL_ERROR;
+	}
+
+	if (Tcl_GetIndexFromObj(interp, objv[1], logpriorities, "priority",
+							TCL_EXACT, &priIndex) != TCL_OK)
+		return TCL_ERROR;
+
+	level = loglevels[priIndex];
+
+	if (level == ERROR)
+	{
+		/*
+		 * We just pass the error back to Tcl.  If it's not caught, it'll
+		 * eventually get converted to a PG error when we reach the call
+		 * handler.
+		 */
+		Tcl_SetObjResult(interp, objv[2]);
+		return TCL_ERROR;
+	}
+
+	/*
+	 * For non-error messages, just pass 'em to ereport().  We do not expect
+	 * that this will fail, but just on the off chance it does, report the
+	 * error back to Tcl.  Note we are assuming that ereport() can't have any
+	 * internal failures that are so bad as to require a transaction abort.
+	 *
+	 * This path is also used for FATAL errors, which aren't going to come
+	 * back to us at all.
+	 */
+	oldcontext = CurrentMemoryContext;
+	PG_TRY();
+	{
+		UTF_BEGIN;
+		ereport(level,
+				(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
+				 errmsg("%s", UTF_U2E(Tcl_GetString(objv[2])))));
+		UTF_END;
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Must reset elog.c's state */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Pass the error data to Tcl */
+		pltcl_construct_errorCode(interp, edata);
+		UTF_BEGIN;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+		UTF_END;
+		FreeErrorData(edata);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_construct_errorCode()		- construct a Tcl errorCode
+ *		list with detailed information from the PostgreSQL server
+ **********************************************************************/
+static void
+pltcl_construct_errorCode(Tcl_Interp *interp, ErrorData *edata)
+{
+	Tcl_Obj    *obj = Tcl_NewObj();
+
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj("POSTGRES", -1));
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj(PG_VERSION, -1));
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj("SQLSTATE", -1));
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj(unpack_sql_state(edata->sqlerrcode), -1));
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj("condition", -1));
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj(pltcl_get_condition_name(edata->sqlerrcode), -1));
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj("message", -1));
+	UTF_BEGIN;
+	Tcl_ListObjAppendElement(interp, obj,
+							 Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+	UTF_END;
+	if (edata->detail)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("detail", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->detail), -1));
+		UTF_END;
+	}
+	if (edata->hint)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("hint", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->hint), -1));
+		UTF_END;
+	}
+	if (edata->context)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("context", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->context), -1));
+		UTF_END;
+	}
+	if (edata->schema_name)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("schema", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->schema_name), -1));
+		UTF_END;
+	}
+	if (edata->table_name)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("table", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->table_name), -1));
+		UTF_END;
+	}
+	if (edata->column_name)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("column", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->column_name), -1));
+		UTF_END;
+	}
+	if (edata->datatype_name)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("datatype", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->datatype_name), -1));
+		UTF_END;
+	}
+	if (edata->constraint_name)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("constraint", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->constraint_name), -1));
+		UTF_END;
+	}
+	/* cursorpos is never interesting here; report internal query/pos */
+	if (edata->internalquery)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("statement", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->internalquery), -1));
+		UTF_END;
+	}
+	if (edata->internalpos > 0)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("cursor_position", -1));
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewIntObj(edata->internalpos));
+	}
+	if (edata->filename)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("filename", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->filename), -1));
+		UTF_END;
+	}
+	if (edata->lineno > 0)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("lineno", -1));
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewIntObj(edata->lineno));
+	}
+	if (edata->funcname)
+	{
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj("funcname", -1));
+		UTF_BEGIN;
+		Tcl_ListObjAppendElement(interp, obj,
+								 Tcl_NewStringObj(UTF_E2U(edata->funcname), -1));
+		UTF_END;
+	}
+
+	Tcl_SetObjErrorCode(interp, obj);
+}
+
+
+/**********************************************************************
+ * pltcl_get_condition_name()	- find name for SQLSTATE
+ **********************************************************************/
+static const char *
+pltcl_get_condition_name(int sqlstate)
+{
+	int			i;
+
+	for (i = 0; exception_name_map[i].label != NULL; i++)
+	{
+		if (exception_name_map[i].sqlerrstate == sqlstate)
+			return exception_name_map[i].label;
+	}
+	return "unrecognized_sqlstate";
+}
+
+
+/**********************************************************************
+ * pltcl_quote()	- quote literal strings that are to
+ *			  be used in SPI_execute query strings
+ **********************************************************************/
+static int
+pltcl_quote(ClientData cdata, Tcl_Interp *interp,
+			int objc, Tcl_Obj *const objv[])
+{
+	char	   *tmp;
+	const char *cp1;
+	char	   *cp2;
+	int			length;
+
+	/************************************************************
+	 * Check call syntax
+	 ************************************************************/
+	if (objc != 2)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv, "string");
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Allocate space for the maximum the string can
+	 * grow to and initialize pointers
+	 ************************************************************/
+	cp1 = Tcl_GetStringFromObj(objv[1], &length);
+	tmp = palloc(length * 2 + 1);
+	cp2 = tmp;
+
+	/************************************************************
+	 * Walk through string and double every quote and backslash
+	 ************************************************************/
+	while (*cp1)
+	{
+		if (*cp1 == '\'')
+			*cp2++ = '\'';
+		else
+		{
+			if (*cp1 == '\\')
+				*cp2++ = '\\';
+		}
+		*cp2++ = *cp1++;
+	}
+
+	/************************************************************
+	 * Terminate the string and set it as result
+	 ************************************************************/
+	*cp2 = '\0';
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(tmp, -1));
+	pfree(tmp);
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_argisnull()	- determine if a specific argument is NULL
+ **********************************************************************/
+static int
+pltcl_argisnull(ClientData cdata, Tcl_Interp *interp,
+				int objc, Tcl_Obj *const objv[])
+{
+	int			argno;
+	FunctionCallInfo fcinfo = pltcl_current_call_state->fcinfo;
+
+	/************************************************************
+	 * Check call syntax
+	 ************************************************************/
+	if (objc != 2)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv, "argno");
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Check that we're called as a normal function
+	 ************************************************************/
+	if (fcinfo == NULL)
+	{
+		Tcl_SetObjResult(interp,
+						 Tcl_NewStringObj("argisnull cannot be used in triggers", -1));
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Get the argument number
+	 ************************************************************/
+	if (Tcl_GetIntFromObj(interp, objv[1], &argno) != TCL_OK)
+		return TCL_ERROR;
+
+	/************************************************************
+	 * Check that the argno is valid
+	 ************************************************************/
+	argno--;
+	if (argno < 0 || argno >= fcinfo->nargs)
+	{
+		Tcl_SetObjResult(interp,
+						 Tcl_NewStringObj("argno out of range", -1));
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Get the requested NULL state
+	 ************************************************************/
+	Tcl_SetObjResult(interp, Tcl_NewBooleanObj(PG_ARGISNULL(argno)));
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_returnnull()	- Cause a NULL return from the current function
+ **********************************************************************/
+static int
+pltcl_returnnull(ClientData cdata, Tcl_Interp *interp,
+				 int objc, Tcl_Obj *const objv[])
+{
+	FunctionCallInfo fcinfo = pltcl_current_call_state->fcinfo;
+
+	/************************************************************
+	 * Check call syntax
+	 ************************************************************/
+	if (objc != 1)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv, "");
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Check that we're called as a normal function
+	 ************************************************************/
+	if (fcinfo == NULL)
+	{
+		Tcl_SetObjResult(interp,
+						 Tcl_NewStringObj("return_null cannot be used in triggers", -1));
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Set the NULL return flag and cause Tcl to return from the
+	 * procedure.
+	 ************************************************************/
+	fcinfo->isnull = true;
+
+	return TCL_RETURN;
+}
+
+
+/**********************************************************************
+ * pltcl_returnnext()	- Add a row to the result tuplestore in a SRF.
+ **********************************************************************/
+static int
+pltcl_returnnext(ClientData cdata, Tcl_Interp *interp,
+				 int objc, Tcl_Obj *const objv[])
+{
+	pltcl_call_state *call_state = pltcl_current_call_state;
+	FunctionCallInfo fcinfo = call_state->fcinfo;
+	pltcl_proc_desc *prodesc = call_state->prodesc;
+	MemoryContext oldcontext = CurrentMemoryContext;
+	ResourceOwner oldowner = CurrentResourceOwner;
+	volatile int result = TCL_OK;
+
+	/*
+	 * Check that we're called as a set-returning function
+	 */
+	if (fcinfo == NULL)
+	{
+		Tcl_SetObjResult(interp,
+						 Tcl_NewStringObj("return_next cannot be used in triggers", -1));
+		return TCL_ERROR;
+	}
+
+	if (!prodesc->fn_retisset)
+	{
+		Tcl_SetObjResult(interp,
+						 Tcl_NewStringObj("return_next cannot be used in non-set-returning functions", -1));
+		return TCL_ERROR;
+	}
+
+	/*
+	 * Check call syntax
+	 */
+	if (objc != 2)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv, "result");
+		return TCL_ERROR;
+	}
+
+	/*
+	 * The rest might throw elog(ERROR), so must run in a subtransaction.
+	 *
+	 * A small advantage of using a subtransaction is that it provides a
+	 * short-lived memory context for free, so we needn't worry about leaking
+	 * memory here.  To use that context, call BeginInternalSubTransaction
+	 * directly instead of going through pltcl_subtrans_begin.
+	 */
+	BeginInternalSubTransaction(NULL);
+	PG_TRY();
+	{
+		/* Set up tuple store if first output row */
+		if (call_state->tuple_store == NULL)
+			pltcl_init_tuple_store(call_state);
+
+		if (prodesc->fn_retistuple)
+		{
+			Tcl_Obj   **rowObjv;
+			int			rowObjc;
+
+			/* result should be a list, so break it down */
+			if (Tcl_ListObjGetElements(interp, objv[1], &rowObjc, &rowObjv) == TCL_ERROR)
+				result = TCL_ERROR;
+			else
+			{
+				HeapTuple	tuple;
+
+				tuple = pltcl_build_tuple_result(interp, rowObjv, rowObjc,
+												 call_state);
+				tuplestore_puttuple(call_state->tuple_store, tuple);
+			}
+		}
+		else
+		{
+			Datum		retval;
+			bool		isNull = false;
+
+			/* for paranoia's sake, check that tupdesc has exactly one column */
+			if (call_state->ret_tupdesc->natts != 1)
+				elog(ERROR, "wrong result type supplied in return_next");
+
+			retval = InputFunctionCall(&prodesc->result_in_func,
+									   utf_u2e((char *) Tcl_GetString(objv[1])),
+									   prodesc->result_typioparam,
+									   -1);
+			tuplestore_putvalues(call_state->tuple_store, call_state->ret_tupdesc,
+								 &retval, &isNull);
+		}
+
+		pltcl_subtrans_commit(oldcontext, oldowner);
+	}
+	PG_CATCH();
+	{
+		pltcl_subtrans_abort(interp, oldcontext, oldowner);
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return result;
+}
+
+
+/*----------
+ * Support for running SPI operations inside subtransactions
+ *
+ * Intended usage pattern is:
+ *
+ *	MemoryContext oldcontext = CurrentMemoryContext;
+ *	ResourceOwner oldowner = CurrentResourceOwner;
+ *
+ *	...
+ *	pltcl_subtrans_begin(oldcontext, oldowner);
+ *	PG_TRY();
+ *	{
+ *		do something risky;
+ *		pltcl_subtrans_commit(oldcontext, oldowner);
+ *	}
+ *	PG_CATCH();
+ *	{
+ *		pltcl_subtrans_abort(interp, oldcontext, oldowner);
+ *		return TCL_ERROR;
+ *	}
+ *	PG_END_TRY();
+ *	return TCL_OK;
+ *----------
+ */
+static void
+pltcl_subtrans_begin(MemoryContext oldcontext, ResourceOwner oldowner)
+{
+	BeginInternalSubTransaction(NULL);
+
+	/* Want to run inside function's memory context */
+	MemoryContextSwitchTo(oldcontext);
+}
+
+static void
+pltcl_subtrans_commit(MemoryContext oldcontext, ResourceOwner oldowner)
+{
+	/* Commit the inner transaction, return to outer xact context */
+	ReleaseCurrentSubTransaction();
+	MemoryContextSwitchTo(oldcontext);
+	CurrentResourceOwner = oldowner;
+}
+
+static void
+pltcl_subtrans_abort(Tcl_Interp *interp,
+					 MemoryContext oldcontext, ResourceOwner oldowner)
+{
+	ErrorData  *edata;
+
+	/* Save error info */
+	MemoryContextSwitchTo(oldcontext);
+	edata = CopyErrorData();
+	FlushErrorState();
+
+	/* Abort the inner transaction */
+	RollbackAndReleaseCurrentSubTransaction();
+	MemoryContextSwitchTo(oldcontext);
+	CurrentResourceOwner = oldowner;
+
+	/* Pass the error data to Tcl */
+	pltcl_construct_errorCode(interp, edata);
+	UTF_BEGIN;
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+	UTF_END;
+	FreeErrorData(edata);
+}
+
+
+/**********************************************************************
+ * pltcl_SPI_execute()		- The builtin SPI_execute command
+ *				  for the Tcl interpreter
+ **********************************************************************/
+static int
+pltcl_SPI_execute(ClientData cdata, Tcl_Interp *interp,
+				  int objc, Tcl_Obj *const objv[])
+{
+	int			my_rc;
+	int			spi_rc;
+	int			query_idx;
+	int			i;
+	int			optIndex;
+	int			count = 0;
+	const char *volatile arrayname = NULL;
+	Tcl_Obj    *volatile loop_body = NULL;
+	MemoryContext oldcontext = CurrentMemoryContext;
+	ResourceOwner oldowner = CurrentResourceOwner;
+
+	enum options
+	{
+		OPT_ARRAY, OPT_COUNT
+	};
+
+	static const char *options[] = {
+		"-array", "-count", (const char *) NULL
+	};
+
+	/************************************************************
+	 * Check the call syntax and get the options
+	 ************************************************************/
+	if (objc < 2)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv,
+						 "?-count n? ?-array name? query ?loop body?");
+		return TCL_ERROR;
+	}
+
+	i = 1;
+	while (i < objc)
+	{
+		if (Tcl_GetIndexFromObj(NULL, objv[i], options, NULL,
+								TCL_EXACT, &optIndex) != TCL_OK)
+			break;
+
+		if (++i >= objc)
+		{
+			Tcl_SetObjResult(interp,
+							 Tcl_NewStringObj("missing argument to -count or -array", -1));
+			return TCL_ERROR;
+		}
+
+		switch ((enum options) optIndex)
+		{
+			case OPT_ARRAY:
+				arrayname = Tcl_GetString(objv[i++]);
+				break;
+
+			case OPT_COUNT:
+				if (Tcl_GetIntFromObj(interp, objv[i++], &count) != TCL_OK)
+					return TCL_ERROR;
+				break;
+		}
+	}
+
+	query_idx = i;
+	if (query_idx >= objc || query_idx + 2 < objc)
+	{
+		Tcl_WrongNumArgs(interp, query_idx - 1, objv, "query ?loop body?");
+		return TCL_ERROR;
+	}
+
+	if (query_idx + 1 < objc)
+		loop_body = objv[query_idx + 1];
+
+	/************************************************************
+	 * Execute the query inside a sub-transaction, so we can cope with
+	 * errors sanely
+	 ************************************************************/
+
+	pltcl_subtrans_begin(oldcontext, oldowner);
+
+	PG_TRY();
+	{
+		UTF_BEGIN;
+		spi_rc = SPI_execute(UTF_U2E(Tcl_GetString(objv[query_idx])),
+							 pltcl_current_call_state->prodesc->fn_readonly, count);
+		UTF_END;
+
+		my_rc = pltcl_process_SPI_result(interp,
+										 arrayname,
+										 loop_body,
+										 spi_rc,
+										 SPI_tuptable,
+										 SPI_processed);
+
+		pltcl_subtrans_commit(oldcontext, oldowner);
+	}
+	PG_CATCH();
+	{
+		pltcl_subtrans_abort(interp, oldcontext, oldowner);
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return my_rc;
+}
+
+/*
+ * Process the result from SPI_execute or SPI_execute_plan
+ *
+ * Shared code between pltcl_SPI_execute and pltcl_SPI_execute_plan
+ */
+static int
+pltcl_process_SPI_result(Tcl_Interp *interp,
+						 const char *arrayname,
+						 Tcl_Obj *loop_body,
+						 int spi_rc,
+						 SPITupleTable *tuptable,
+						 uint64 ntuples)
+{
+	int			my_rc = TCL_OK;
+	int			loop_rc;
+	HeapTuple  *tuples;
+	TupleDesc	tupdesc;
+
+	switch (spi_rc)
+	{
+		case SPI_OK_SELINTO:
+		case SPI_OK_INSERT:
+		case SPI_OK_DELETE:
+		case SPI_OK_UPDATE:
+		case SPI_OK_MERGE:
+			Tcl_SetObjResult(interp, Tcl_NewWideIntObj(ntuples));
+			break;
+
+		case SPI_OK_UTILITY:
+		case SPI_OK_REWRITTEN:
+			if (tuptable == NULL)
+			{
+				Tcl_SetObjResult(interp, Tcl_NewIntObj(0));
+				break;
+			}
+			/* fall through for utility returning tuples */
+			/* FALLTHROUGH */
+
+		case SPI_OK_SELECT:
+		case SPI_OK_INSERT_RETURNING:
+		case SPI_OK_DELETE_RETURNING:
+		case SPI_OK_UPDATE_RETURNING:
+
+			/*
+			 * Process the tuples we got
+			 */
+			tuples = tuptable->vals;
+			tupdesc = tuptable->tupdesc;
+
+			if (loop_body == NULL)
+			{
+				/*
+				 * If there is no loop body given, just set the variables from
+				 * the first tuple (if any)
+				 */
+				if (ntuples > 0)
+					pltcl_set_tuple_values(interp, arrayname, 0,
+										   tuples[0], tupdesc);
+			}
+			else
+			{
+				/*
+				 * There is a loop body - process all tuples and evaluate the
+				 * body on each
+				 */
+				uint64		i;
+
+				for (i = 0; i < ntuples; i++)
+				{
+					pltcl_set_tuple_values(interp, arrayname, i,
+										   tuples[i], tupdesc);
+
+					loop_rc = Tcl_EvalObjEx(interp, loop_body, 0);
+
+					if (loop_rc == TCL_OK)
+						continue;
+					if (loop_rc == TCL_CONTINUE)
+						continue;
+					if (loop_rc == TCL_RETURN)
+					{
+						my_rc = TCL_RETURN;
+						break;
+					}
+					if (loop_rc == TCL_BREAK)
+						break;
+					my_rc = TCL_ERROR;
+					break;
+				}
+			}
+
+			if (my_rc == TCL_OK)
+			{
+				Tcl_SetObjResult(interp, Tcl_NewWideIntObj(ntuples));
+			}
+			break;
+
+		default:
+			Tcl_AppendResult(interp, "pltcl: SPI_execute failed: ",
+							 SPI_result_code_string(spi_rc), NULL);
+			my_rc = TCL_ERROR;
+			break;
+	}
+
+	SPI_freetuptable(tuptable);
+
+	return my_rc;
+}
+
+
+/**********************************************************************
+ * pltcl_SPI_prepare()		- Builtin support for prepared plans
+ *				  The Tcl command SPI_prepare
+ *				  always saves the plan using
+ *				  SPI_keepplan and returns a key for
+ *				  access. There is no chance to prepare
+ *				  and not save the plan currently.
+ **********************************************************************/
+static int
+pltcl_SPI_prepare(ClientData cdata, Tcl_Interp *interp,
+				  int objc, Tcl_Obj *const objv[])
+{
+	volatile MemoryContext plan_cxt = NULL;
+	int			nargs;
+	Tcl_Obj   **argsObj;
+	pltcl_query_desc *qdesc;
+	int			i;
+	Tcl_HashEntry *hashent;
+	int			hashnew;
+	Tcl_HashTable *query_hash;
+	MemoryContext oldcontext = CurrentMemoryContext;
+	ResourceOwner oldowner = CurrentResourceOwner;
+
+	/************************************************************
+	 * Check the call syntax
+	 ************************************************************/
+	if (objc != 3)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv, "query argtypes");
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Split the argument type list
+	 ************************************************************/
+	if (Tcl_ListObjGetElements(interp, objv[2], &nargs, &argsObj) != TCL_OK)
+		return TCL_ERROR;
+
+	/************************************************************
+	 * Allocate the new querydesc structure
+	 *
+	 * struct qdesc and subsidiary data all live in plan_cxt.  Note that if the
+	 * function is recompiled for whatever reason, permanent memory leaks
+	 * occur.  FIXME someday.
+	 ************************************************************/
+	plan_cxt = AllocSetContextCreate(TopMemoryContext,
+									 "PL/Tcl spi_prepare query",
+									 ALLOCSET_SMALL_SIZES);
+	MemoryContextSwitchTo(plan_cxt);
+	qdesc = (pltcl_query_desc *) palloc0(sizeof(pltcl_query_desc));
+	snprintf(qdesc->qname, sizeof(qdesc->qname), "%p", qdesc);
+	qdesc->nargs = nargs;
+	qdesc->argtypes = (Oid *) palloc(nargs * sizeof(Oid));
+	qdesc->arginfuncs = (FmgrInfo *) palloc(nargs * sizeof(FmgrInfo));
+	qdesc->argtypioparams = (Oid *) palloc(nargs * sizeof(Oid));
+	MemoryContextSwitchTo(oldcontext);
+
+	/************************************************************
+	 * Execute the prepare inside a sub-transaction, so we can cope with
+	 * errors sanely
+	 ************************************************************/
+
+	pltcl_subtrans_begin(oldcontext, oldowner);
+
+	PG_TRY();
+	{
+		/************************************************************
+		 * Resolve argument type names and then look them up by oid
+		 * in the system cache, and remember the required information
+		 * for input conversion.
+		 ************************************************************/
+		for (i = 0; i < nargs; i++)
+		{
+			Oid			typId,
+						typInput,
+						typIOParam;
+			int32		typmod;
+
+			parseTypeString(Tcl_GetString(argsObj[i]), &typId, &typmod, false);
+
+			getTypeInputInfo(typId, &typInput, &typIOParam);
+
+			qdesc->argtypes[i] = typId;
+			fmgr_info_cxt(typInput, &(qdesc->arginfuncs[i]), plan_cxt);
+			qdesc->argtypioparams[i] = typIOParam;
+		}
+
+		/************************************************************
+		 * Prepare the plan and check for errors
+		 ************************************************************/
+		UTF_BEGIN;
+		qdesc->plan = SPI_prepare(UTF_U2E(Tcl_GetString(objv[1])),
+								  nargs, qdesc->argtypes);
+		UTF_END;
+
+		if (qdesc->plan == NULL)
+			elog(ERROR, "SPI_prepare() failed");
+
+		/************************************************************
+		 * Save the plan into permanent memory (right now it's in the
+		 * SPI procCxt, which will go away at function end).
+		 ************************************************************/
+		if (SPI_keepplan(qdesc->plan))
+			elog(ERROR, "SPI_keepplan() failed");
+
+		pltcl_subtrans_commit(oldcontext, oldowner);
+	}
+	PG_CATCH();
+	{
+		pltcl_subtrans_abort(interp, oldcontext, oldowner);
+
+		MemoryContextDelete(plan_cxt);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	/************************************************************
+	 * Insert a hashtable entry for the plan and return
+	 * the key to the caller
+	 ************************************************************/
+	query_hash = &pltcl_current_call_state->prodesc->interp_desc->query_hash;
+
+	hashent = Tcl_CreateHashEntry(query_hash, qdesc->qname, &hashnew);
+	Tcl_SetHashValue(hashent, (ClientData) qdesc);
+
+	/* qname is ASCII, so no need for encoding conversion */
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(qdesc->qname, -1));
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_SPI_execute_plan()		- Execute a prepared plan
+ **********************************************************************/
+static int
+pltcl_SPI_execute_plan(ClientData cdata, Tcl_Interp *interp,
+					   int objc, Tcl_Obj *const objv[])
+{
+	int			my_rc;
+	int			spi_rc;
+	int			i;
+	int			j;
+	int			optIndex;
+	Tcl_HashEntry *hashent;
+	pltcl_query_desc *qdesc;
+	const char *nulls = NULL;
+	const char *arrayname = NULL;
+	Tcl_Obj    *loop_body = NULL;
+	int			count = 0;
+	int			callObjc;
+	Tcl_Obj   **callObjv = NULL;
+	Datum	   *argvalues;
+	MemoryContext oldcontext = CurrentMemoryContext;
+	ResourceOwner oldowner = CurrentResourceOwner;
+	Tcl_HashTable *query_hash;
+
+	enum options
+	{
+		OPT_ARRAY, OPT_COUNT, OPT_NULLS
+	};
+
+	static const char *options[] = {
+		"-array", "-count", "-nulls", (const char *) NULL
+	};
+
+	/************************************************************
+	 * Get the options and check syntax
+	 ************************************************************/
+	i = 1;
+	while (i < objc)
+	{
+		if (Tcl_GetIndexFromObj(NULL, objv[i], options, NULL,
+								TCL_EXACT, &optIndex) != TCL_OK)
+			break;
+
+		if (++i >= objc)
+		{
+			Tcl_SetObjResult(interp,
+							 Tcl_NewStringObj("missing argument to -array, -count or -nulls", -1));
+			return TCL_ERROR;
+		}
+
+		switch ((enum options) optIndex)
+		{
+			case OPT_ARRAY:
+				arrayname = Tcl_GetString(objv[i++]);
+				break;
+
+			case OPT_COUNT:
+				if (Tcl_GetIntFromObj(interp, objv[i++], &count) != TCL_OK)
+					return TCL_ERROR;
+				break;
+
+			case OPT_NULLS:
+				nulls = Tcl_GetString(objv[i++]);
+				break;
+		}
+	}
+
+	/************************************************************
+	 * Get the prepared plan descriptor by its key
+	 ************************************************************/
+	if (i >= objc)
+	{
+		Tcl_SetObjResult(interp,
+						 Tcl_NewStringObj("missing argument to -count or -array", -1));
+		return TCL_ERROR;
+	}
+
+	query_hash = &pltcl_current_call_state->prodesc->interp_desc->query_hash;
+
+	hashent = Tcl_FindHashEntry(query_hash, Tcl_GetString(objv[i]));
+	if (hashent == NULL)
+	{
+		Tcl_AppendResult(interp, "invalid queryid '", Tcl_GetString(objv[i]), "'", NULL);
+		return TCL_ERROR;
+	}
+	qdesc = (pltcl_query_desc *) Tcl_GetHashValue(hashent);
+	i++;
+
+	/************************************************************
+	 * If a nulls string is given, check for correct length
+	 ************************************************************/
+	if (nulls != NULL)
+	{
+		if (strlen(nulls) != qdesc->nargs)
+		{
+			Tcl_SetObjResult(interp,
+							 Tcl_NewStringObj("length of nulls string doesn't match number of arguments",
+											  -1));
+			return TCL_ERROR;
+		}
+	}
+
+	/************************************************************
+	 * If there was an argtype list on preparation, we need
+	 * an argument value list now
+	 ************************************************************/
+	if (qdesc->nargs > 0)
+	{
+		if (i >= objc)
+		{
+			Tcl_SetObjResult(interp,
+							 Tcl_NewStringObj("argument list length doesn't match number of arguments for query",
+											  -1));
+			return TCL_ERROR;
+		}
+
+		/************************************************************
+		 * Split the argument values
+		 ************************************************************/
+		if (Tcl_ListObjGetElements(interp, objv[i++], &callObjc, &callObjv) != TCL_OK)
+			return TCL_ERROR;
+
+		/************************************************************
+		 * Check that the number of arguments matches
+		 ************************************************************/
+		if (callObjc != qdesc->nargs)
+		{
+			Tcl_SetObjResult(interp,
+							 Tcl_NewStringObj("argument list length doesn't match number of arguments for query",
+											  -1));
+			return TCL_ERROR;
+		}
+	}
+	else
+		callObjc = 0;
+
+	/************************************************************
+	 * Get loop body if present
+	 ************************************************************/
+	if (i < objc)
+		loop_body = objv[i++];
+
+	if (i != objc)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv,
+						 "?-count n? ?-array name? ?-nulls string? "
+						 "query ?args? ?loop body?");
+		return TCL_ERROR;
+	}
+
+	/************************************************************
+	 * Execute the plan inside a sub-transaction, so we can cope with
+	 * errors sanely
+	 ************************************************************/
+
+	pltcl_subtrans_begin(oldcontext, oldowner);
+
+	PG_TRY();
+	{
+		/************************************************************
+		 * Setup the value array for SPI_execute_plan() using
+		 * the type specific input functions
+		 ************************************************************/
+		argvalues = (Datum *) palloc(callObjc * sizeof(Datum));
+
+		for (j = 0; j < callObjc; j++)
+		{
+			if (nulls && nulls[j] == 'n')
+			{
+				argvalues[j] = InputFunctionCall(&qdesc->arginfuncs[j],
+												 NULL,
+												 qdesc->argtypioparams[j],
+												 -1);
+			}
+			else
+			{
+				UTF_BEGIN;
+				argvalues[j] = InputFunctionCall(&qdesc->arginfuncs[j],
+												 UTF_U2E(Tcl_GetString(callObjv[j])),
+												 qdesc->argtypioparams[j],
+												 -1);
+				UTF_END;
+			}
+		}
+
+		/************************************************************
+		 * Execute the plan
+		 ************************************************************/
+		spi_rc = SPI_execute_plan(qdesc->plan, argvalues, nulls,
+								  pltcl_current_call_state->prodesc->fn_readonly,
+								  count);
+
+		my_rc = pltcl_process_SPI_result(interp,
+										 arrayname,
+										 loop_body,
+										 spi_rc,
+										 SPI_tuptable,
+										 SPI_processed);
+
+		pltcl_subtrans_commit(oldcontext, oldowner);
+	}
+	PG_CATCH();
+	{
+		pltcl_subtrans_abort(interp, oldcontext, oldowner);
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return my_rc;
+}
+
+
+/**********************************************************************
+ * pltcl_subtransaction()	- Execute some Tcl code in a subtransaction
+ *
+ * The subtransaction is aborted if the Tcl code fragment returns TCL_ERROR,
+ * otherwise it's subcommitted.
+ **********************************************************************/
+static int
+pltcl_subtransaction(ClientData cdata, Tcl_Interp *interp,
+					 int objc, Tcl_Obj *const objv[])
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+	ResourceOwner oldowner = CurrentResourceOwner;
+	int			retcode;
+
+	if (objc != 2)
+	{
+		Tcl_WrongNumArgs(interp, 1, objv, "command");
+		return TCL_ERROR;
+	}
+
+	/*
+	 * Note: we don't use pltcl_subtrans_begin and friends here because we
+	 * don't want the error handling in pltcl_subtrans_abort.  But otherwise
+	 * the processing should be about the same as in those functions.
+	 */
+	BeginInternalSubTransaction(NULL);
+	MemoryContextSwitchTo(oldcontext);
+
+	retcode = Tcl_EvalObjEx(interp, objv[1], 0);
+
+	if (retcode == TCL_ERROR)
+	{
+		/* Rollback the subtransaction */
+		RollbackAndReleaseCurrentSubTransaction();
+	}
+	else
+	{
+		/* Commit the subtransaction */
+		ReleaseCurrentSubTransaction();
+	}
+
+	/* In either case, restore previous memory context and resource owner */
+	MemoryContextSwitchTo(oldcontext);
+	CurrentResourceOwner = oldowner;
+
+	return retcode;
+}
+
+
+/**********************************************************************
+ * pltcl_commit()
+ *
+ * Commit the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_commit(ClientData cdata, Tcl_Interp *interp,
+			 int objc, Tcl_Obj *const objv[])
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_commit();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Pass the error data to Tcl */
+		pltcl_construct_errorCode(interp, edata);
+		UTF_BEGIN;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+		UTF_END;
+		FreeErrorData(edata);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_rollback()
+ *
+ * Abort the transaction and start a new one.
+ **********************************************************************/
+static int
+pltcl_rollback(ClientData cdata, Tcl_Interp *interp,
+			   int objc, Tcl_Obj *const objv[])
+{
+	MemoryContext oldcontext = CurrentMemoryContext;
+
+	PG_TRY();
+	{
+		SPI_rollback();
+	}
+	PG_CATCH();
+	{
+		ErrorData  *edata;
+
+		/* Save error info */
+		MemoryContextSwitchTo(oldcontext);
+		edata = CopyErrorData();
+		FlushErrorState();
+
+		/* Pass the error data to Tcl */
+		pltcl_construct_errorCode(interp, edata);
+		UTF_BEGIN;
+		Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1));
+		UTF_END;
+		FreeErrorData(edata);
+
+		return TCL_ERROR;
+	}
+	PG_END_TRY();
+
+	return TCL_OK;
+}
+
+
+/**********************************************************************
+ * pltcl_set_tuple_values() - Set variables for all attributes
+ *				  of a given tuple
+ *
+ * Note: arrayname is presumed to be UTF8; it usually came from Tcl
+ **********************************************************************/
+static void
+pltcl_set_tuple_values(Tcl_Interp *interp, const char *arrayname,
+					   uint64 tupno, HeapTuple tuple, TupleDesc tupdesc)
+{
+	int			i;
+	char	   *outputstr;
+	Datum		attr;
+	bool		isnull;
+	const char *attname;
+	Oid			typoutput;
+	bool		typisvarlena;
+	const char **arrptr;
+	const char **nameptr;
+	const char *nullname = NULL;
+
+	/************************************************************
+	 * Prepare pointers for Tcl_SetVar2Ex() below
+	 ************************************************************/
+	if (arrayname == NULL)
+	{
+		arrptr = &attname;
+		nameptr = &nullname;
+	}
+	else
+	{
+		arrptr = &arrayname;
+		nameptr = &attname;
+
+		/*
+		 * When outputting to an array, fill the ".tupno" element with the
+		 * current tuple number.  This will be overridden below if ".tupno" is
+		 * in use as an actual field name in the rowtype.
+		 */
+		Tcl_SetVar2Ex(interp, arrayname, ".tupno", Tcl_NewWideIntObj(tupno), 0);
+	}
+
+	for (i = 0; i < tupdesc->natts; i++)
+	{
+		Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+		/* ignore dropped attributes */
+		if (att->attisdropped)
+			continue;
+
+		/************************************************************
+		 * Get the attribute name
+		 ************************************************************/
+		UTF_BEGIN;
+		attname = pstrdup(UTF_E2U(NameStr(att->attname)));
+		UTF_END;
+
+		/************************************************************
+		 * Get the attributes value
+		 ************************************************************/
+		attr = heap_getattr(tuple, i + 1, tupdesc, &isnull);
+
+		/************************************************************
+		 * If there is a value, set the variable
+		 * If not, unset it
+		 *
+		 * Hmmm - Null attributes will cause functions to
+		 *		  crash if they don't expect them - need something
+		 *		  smarter here.
+		 ************************************************************/
+		if (!isnull)
+		{
+			getTypeOutputInfo(att->atttypid, &typoutput, &typisvarlena);
+			outputstr = OidOutputFunctionCall(typoutput, attr);
+			UTF_BEGIN;
+			Tcl_SetVar2Ex(interp, *arrptr, *nameptr,
+						  Tcl_NewStringObj(UTF_E2U(outputstr), -1), 0);
+			UTF_END;
+			pfree(outputstr);
+		}
+		else
+			Tcl_UnsetVar2(interp, *arrptr, *nameptr, 0);
+
+		pfree(unconstify(char *, attname));
+	}
+}
+
+
+/**********************************************************************
+ * pltcl_build_tuple_argument() - Build a list object usable for 'array set'
+ *				  from all attributes of a given tuple
+ **********************************************************************/
+static Tcl_Obj *
+pltcl_build_tuple_argument(HeapTuple tuple, TupleDesc tupdesc, bool include_generated)
+{
+	Tcl_Obj    *retobj = Tcl_NewObj();
+	int			i;
+	char	   *outputstr;
+	Datum		attr;
+	bool		isnull;
+	char	   *attname;
+	Oid			typoutput;
+	bool		typisvarlena;
+
+	for (i = 0; i < tupdesc->natts; i++)
+	{
+		Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+		/* ignore dropped attributes */
+		if (att->attisdropped)
+			continue;
+
+		if (att->attgenerated)
+		{
+			/* don't include unless requested */
+			if (!include_generated)
+				continue;
+		}
+
+		/************************************************************
+		 * Get the attribute name
+		 ************************************************************/
+		attname = NameStr(att->attname);
+
+		/************************************************************
+		 * Get the attributes value
+		 ************************************************************/
+		attr = heap_getattr(tuple, i + 1, tupdesc, &isnull);
+
+		/************************************************************
+		 * If there is a value, append the attribute name and the
+		 * value to the list
+		 *
+		 * Hmmm - Null attributes will cause functions to
+		 *		  crash if they don't expect them - need something
+		 *		  smarter here.
+		 ************************************************************/
+		if (!isnull)
+		{
+			getTypeOutputInfo(att->atttypid,
+							  &typoutput, &typisvarlena);
+			outputstr = OidOutputFunctionCall(typoutput, attr);
+			UTF_BEGIN;
+			Tcl_ListObjAppendElement(NULL, retobj,
+									 Tcl_NewStringObj(UTF_E2U(attname), -1));
+			UTF_END;
+			UTF_BEGIN;
+			Tcl_ListObjAppendElement(NULL, retobj,
+									 Tcl_NewStringObj(UTF_E2U(outputstr), -1));
+			UTF_END;
+			pfree(outputstr);
+		}
+	}
+
+	return retobj;
+}
+
+/**********************************************************************
+ * pltcl_build_tuple_result() - Build a tuple of function's result rowtype
+ *				  from a Tcl list of column names and values
+ *
+ * In a trigger function, we build a tuple of the trigger table's rowtype.
+ *
+ * Note: this function leaks memory.  Even if we made it clean up its own
+ * mess, there's no way to prevent the datatype input functions it calls
+ * from leaking.  Run it in a short-lived context, unless we're about to
+ * exit the procedure anyway.
+ **********************************************************************/
+static HeapTuple
+pltcl_build_tuple_result(Tcl_Interp *interp, Tcl_Obj **kvObjv, int kvObjc,
+						 pltcl_call_state *call_state)
+{
+	HeapTuple	tuple;
+	TupleDesc	tupdesc;
+	AttInMetadata *attinmeta;
+	char	  **values;
+	int			i;
+
+	if (call_state->ret_tupdesc)
+	{
+		tupdesc = call_state->ret_tupdesc;
+		attinmeta = call_state->attinmeta;
+	}
+	else if (call_state->trigdata)
+	{
+		tupdesc = RelationGetDescr(call_state->trigdata->tg_relation);
+		attinmeta = TupleDescGetAttInMetadata(tupdesc);
+	}
+	else
+	{
+		elog(ERROR, "PL/Tcl function does not return a tuple");
+		tupdesc = NULL;			/* keep compiler quiet */
+		attinmeta = NULL;
+	}
+
+	values = (char **) palloc0(tupdesc->natts * sizeof(char *));
+
+	if (kvObjc % 2 != 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("column name/value list must have even number of elements")));
+
+	for (i = 0; i < kvObjc; i += 2)
+	{
+		char	   *fieldName = utf_u2e(Tcl_GetString(kvObjv[i]));
+		int			attn = SPI_fnumber(tupdesc, fieldName);
+
+		/*
+		 * We silently ignore ".tupno", if it's present but doesn't match any
+		 * actual output column.  This allows direct use of a row returned by
+		 * pltcl_set_tuple_values().
+		 */
+		if (attn == SPI_ERROR_NOATTRIBUTE)
+		{
+			if (strcmp(fieldName, ".tupno") == 0)
+				continue;
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_COLUMN),
+					 errmsg("column name/value list contains nonexistent column name \"%s\"",
+							fieldName)));
+		}
+
+		if (attn <= 0)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("cannot set system attribute \"%s\"",
+							fieldName)));
+
+		if (TupleDescAttr(tupdesc, attn - 1)->attgenerated)
+			ereport(ERROR,
+					(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
+					 errmsg("cannot set generated column \"%s\"",
+							fieldName)));
+
+		values[attn - 1] = utf_u2e(Tcl_GetString(kvObjv[i + 1]));
+	}
+
+	tuple = BuildTupleFromCStrings(attinmeta, values);
+
+	/* if result type is domain-over-composite, check domain constraints */
+	if (call_state->prodesc->fn_retisdomain)
+		domain_check(HeapTupleGetDatum(tuple), false,
+					 call_state->prodesc->result_typid,
+					 &call_state->prodesc->domain_info,
+					 call_state->prodesc->fn_cxt);
+
+	return tuple;
+}
+
+/**********************************************************************
+ * pltcl_init_tuple_store() - Initialize the result tuplestore for a SRF
+ **********************************************************************/
+static void
+pltcl_init_tuple_store(pltcl_call_state *call_state)
+{
+	ReturnSetInfo *rsi = call_state->rsi;
+	MemoryContext oldcxt;
+	ResourceOwner oldowner;
+
+	/* Should be in a SRF */
+	Assert(rsi);
+	/* Should be first time through */
+	Assert(!call_state->tuple_store);
+	Assert(!call_state->attinmeta);
+
+	/* We expect caller to provide an appropriate result tupdesc */
+	Assert(rsi->expectedDesc);
+	call_state->ret_tupdesc = rsi->expectedDesc;
+
+	/*
+	 * Switch to the right memory context and resource owner for storing the
+	 * tuplestore. If we're within a subtransaction opened for an exception
+	 * block, for example, we must still create the tuplestore in the resource
+	 * owner that was active when this function was entered, and not in the
+	 * subtransaction's resource owner.
+	 */
+	oldcxt = MemoryContextSwitchTo(call_state->tuple_store_cxt);
+	oldowner = CurrentResourceOwner;
+	CurrentResourceOwner = call_state->tuple_store_owner;
+
+	call_state->tuple_store =
+		tuplestore_begin_heap(rsi->allowedModes & SFRM_Materialize_Random,
+							  false, work_mem);
+
+	/* Build attinmeta in this context, too */
+	call_state->attinmeta = TupleDescGetAttInMetadata(call_state->ret_tupdesc);
+
+	CurrentResourceOwner = oldowner;
+	MemoryContextSwitchTo(oldcxt);
+}