pg_proc.c

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/*-------------------------------------------------------------------------
 *
 * pg_proc.c
 *	  routines to support manipulation of the pg_proc relation
 *
 * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_proc.c,v 1.109 2003/10/03 19:26:49 tgl Exp $
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/pg_language.h"
#include "catalog/pg_proc.h"
#include "executor/executor.h"
#include "fmgr.h"
#include "miscadmin.h"
#include "parser/parse_coerce.h"
#include "parser/parse_expr.h"
#include "parser/parse_type.h"
#include "tcop/tcopprot.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/sets.h"
#include "utils/syscache.h"


/* GUC parameter */
bool		check_function_bodies = true;


Datum		fmgr_internal_validator(PG_FUNCTION_ARGS);
Datum		fmgr_c_validator(PG_FUNCTION_ARGS);
Datum		fmgr_sql_validator(PG_FUNCTION_ARGS);


/* ----------------------------------------------------------------
 *		ProcedureCreate
 * ----------------------------------------------------------------
 */
Oid
ProcedureCreate(const char *procedureName,
				Oid procNamespace,
				bool replace,
				bool returnsSet,
				Oid returnType,
				Oid languageObjectId,
				Oid languageValidator,
				const char *prosrc,
				const char *probin,
				bool isAgg,
				bool security_definer,
				bool isStrict,
				char volatility,
				int parameterCount,
				const Oid *parameterTypes)
{
	int			i;
	Relation	rel;
	HeapTuple	tup;
	HeapTuple	oldtup;
	char		nulls[Natts_pg_proc];
	Datum		values[Natts_pg_proc];
	char		replaces[Natts_pg_proc];
	Oid			typev[FUNC_MAX_ARGS];
	Oid			relid;
	NameData	procname;
	TupleDesc	tupDesc;
	Oid			retval;
	bool		is_update;
	ObjectAddress myself,
				referenced;

	/*
	 * sanity checks
	 */
	Assert(PointerIsValid(prosrc));
	Assert(PointerIsValid(probin));

	if (parameterCount < 0 || parameterCount > FUNC_MAX_ARGS)
		ereport(ERROR,
				(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
				 errmsg("functions cannot have more than %d arguments",
						FUNC_MAX_ARGS)));

	/*
	 * Do not allow return type ANYARRAY or ANYELEMENT unless at least one
	 * argument is also ANYARRAY or ANYELEMENT
	 */
	if (returnType == ANYARRAYOID || returnType == ANYELEMENTOID)
	{
		bool		genericParam = false;

		for (i = 0; i < parameterCount; i++)
		{
			if (parameterTypes[i] == ANYARRAYOID ||
				parameterTypes[i] == ANYELEMENTOID)
			{
				genericParam = true;
				break;
			}
		}

		if (!genericParam)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
					 errmsg("cannot determine result data type"),
					 errdetail("A function returning \"anyarray\" or \"anyelement\" must have at least one argument of either type.")));
	}

	/* Make sure we have a zero-padded param type array */
	MemSet(typev, 0, FUNC_MAX_ARGS * sizeof(Oid));
	if (parameterCount > 0)
		memcpy(typev, parameterTypes, parameterCount * sizeof(Oid));

	if (languageObjectId == SQLlanguageId)
	{
		/*
		 * If this call is defining a set, check if the set is already
		 * defined by looking to see whether this call's function text
		 * matches a function already in pg_proc.  If so just return the
		 * OID of the existing set.
		 */
		if (strcmp(procedureName, GENERICSETNAME) == 0)
		{
#ifdef SETS_FIXED

			/*
			 * The code below doesn't work any more because the PROSRC
			 * system cache and the pg_proc_prosrc_index have been
			 * removed. Instead a sequential heap scan or something better
			 * must get implemented. The reason for removing is that
			 * nbtree index crashes if sources exceed 2K --- what's likely
			 * for procedural languages.
			 *
			 * 1999/09/30 Jan
			 */
			text	   *prosrctext;

			prosrctext = DatumGetTextP(DirectFunctionCall1(textin,
											   CStringGetDatum(prosrc)));
			retval = GetSysCacheOid(PROSRC,
									PointerGetDatum(prosrctext),
									0, 0, 0);
			pfree(prosrctext);
			if (OidIsValid(retval))
				return retval;
#else
			elog(ERROR, "lookup for procedure by source needs fix (Jan)");
#endif   /* SETS_FIXED */
		}
	}

	/*
	 * don't allow functions of complex types that have the same name as
	 * existing attributes of the type
	 */
	if (parameterCount == 1 && OidIsValid(typev[0]) &&
		(relid = typeidTypeRelid(typev[0])) != InvalidOid &&
		get_attnum(relid, (char *) procedureName) != InvalidAttrNumber)
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_COLUMN),
				 errmsg("\"%s\" is already an attribute of type %s",
						procedureName, format_type_be(typev[0]))));

	/*
	 * All seems OK; prepare the data to be inserted into pg_proc.
	 */

	for (i = 0; i < Natts_pg_proc; ++i)
	{
		nulls[i] = ' ';
		values[i] = (Datum) NULL;
		replaces[i] = 'r';
	}

	i = 0;
	namestrcpy(&procname, procedureName);
	values[i++] = NameGetDatum(&procname);		/* proname */
	values[i++] = ObjectIdGetDatum(procNamespace);		/* pronamespace */
	values[i++] = Int32GetDatum(GetUserId());	/* proowner */
	values[i++] = ObjectIdGetDatum(languageObjectId);	/* prolang */
	values[i++] = BoolGetDatum(isAgg);	/* proisagg */
	values[i++] = BoolGetDatum(security_definer);		/* prosecdef */
	values[i++] = BoolGetDatum(isStrict);		/* proisstrict */
	values[i++] = BoolGetDatum(returnsSet);		/* proretset */
	values[i++] = CharGetDatum(volatility);		/* provolatile */
	values[i++] = UInt16GetDatum(parameterCount);		/* pronargs */
	values[i++] = ObjectIdGetDatum(returnType); /* prorettype */
	values[i++] = PointerGetDatum(typev);		/* proargtypes */
	values[i++] = DirectFunctionCall1(textin,	/* prosrc */
									  CStringGetDatum(prosrc));
	values[i++] = DirectFunctionCall1(textin,	/* probin */
									  CStringGetDatum(probin));
	/* proacl will be handled below */

	rel = heap_openr(ProcedureRelationName, RowExclusiveLock);
	tupDesc = rel->rd_att;

	/* Check for pre-existing definition */
	oldtup = SearchSysCache(PROCNAMENSP,
							PointerGetDatum(procedureName),
							UInt16GetDatum(parameterCount),
							PointerGetDatum(typev),
							ObjectIdGetDatum(procNamespace));

	if (HeapTupleIsValid(oldtup))
	{
		/* There is one; okay to replace it? */
		Form_pg_proc oldproc = (Form_pg_proc) GETSTRUCT(oldtup);

		if (!replace)
			ereport(ERROR,
					(errcode(ERRCODE_DUPLICATE_FUNCTION),
					 errmsg("function \"%s\" already exists with same argument types",
							procedureName)));
		if (GetUserId() != oldproc->proowner && !superuser())
			aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PROC,
						   procedureName);

		/*
		 * Not okay to change the return type of the existing proc, since
		 * existing rules, views, etc may depend on the return type.
		 */
		if (returnType != oldproc->prorettype ||
			returnsSet != oldproc->proretset)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
				errmsg("cannot change return type of existing function"),
					 errhint("Use DROP FUNCTION first.")));

		/* Can't change aggregate status, either */
		if (oldproc->proisagg != isAgg)
		{
			if (oldproc->proisagg)
				ereport(ERROR,
						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
						 errmsg("function \"%s\" is an aggregate",
								procedureName)));
			else
				ereport(ERROR,
						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
						 errmsg("function \"%s\" is not an aggregate",
								procedureName)));
		}

		/* do not change existing ownership or permissions, either */
		replaces[Anum_pg_proc_proowner - 1] = ' ';
		replaces[Anum_pg_proc_proacl - 1] = ' ';

		/* Okay, do it... */
		tup = heap_modifytuple(oldtup, rel, values, nulls, replaces);
		simple_heap_update(rel, &tup->t_self, tup);

		ReleaseSysCache(oldtup);
		is_update = true;
	}
	else
	{
		/* Creating a new procedure */

		/* start out with empty permissions */
		nulls[Anum_pg_proc_proacl - 1] = 'n';

		tup = heap_formtuple(tupDesc, values, nulls);
		simple_heap_insert(rel, tup);
		is_update = false;
	}

	/* Need to update indexes for either the insert or update case */
	CatalogUpdateIndexes(rel, tup);

	retval = HeapTupleGetOid(tup);

	/*
	 * Create dependencies for the new function.  If we are updating an
	 * existing function, first delete any existing pg_depend entries.
	 */
	if (is_update)
		deleteDependencyRecordsFor(RelOid_pg_proc, retval);

	myself.classId = RelOid_pg_proc;
	myself.objectId = retval;
	myself.objectSubId = 0;

	/* dependency on namespace */
	referenced.classId = get_system_catalog_relid(NamespaceRelationName);
	referenced.objectId = procNamespace;
	referenced.objectSubId = 0;
	recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

	/* dependency on implementation language */
	referenced.classId = get_system_catalog_relid(LanguageRelationName);
	referenced.objectId = languageObjectId;
	referenced.objectSubId = 0;
	recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

	/* dependency on return type */
	referenced.classId = RelOid_pg_type;
	referenced.objectId = returnType;
	referenced.objectSubId = 0;
	recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);

	/* dependency on input types */
	for (i = 0; i < parameterCount; i++)
	{
		referenced.classId = RelOid_pg_type;
		referenced.objectId = typev[i];
		referenced.objectSubId = 0;
		recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
	}

	heap_freetuple(tup);

	heap_close(rel, RowExclusiveLock);

	/* Verify function body */
	if (OidIsValid(languageValidator))
	{
		/* Advance command counter so new tuple can be seen by validator */
		CommandCounterIncrement();
		OidFunctionCall1(languageValidator, ObjectIdGetDatum(retval));
	}

	return retval;
}

/*
 * check_sql_fn_retval() -- check return value of a list of sql parse trees.
 *
 * The return value of a sql function is the value returned by
 * the final query in the function.  We do some ad-hoc type checking here
 * to be sure that the user is returning the type he claims.
 *
 * This is normally applied during function definition, but in the case
 * of a function with polymorphic arguments, we instead apply it during
 * function execution startup.	The rettype is then the actual resolved
 * output type of the function, rather than the declared type.	(Therefore,
 * we should never see ANYARRAY or ANYELEMENT as rettype.)
 */
void
check_sql_fn_retval(Oid rettype, char fn_typtype, List *queryTreeList)
{
	Query	   *parse;
	int			cmd;
	List	   *tlist;
	List	   *tlistitem;
	int			tlistlen;
	Oid			typerelid;
	Oid			restype;
	Relation	reln;
	int			relnatts;		/* physical number of columns in rel */
	int			rellogcols;		/* # of nondeleted columns in rel */
	int			colindex;		/* physical column index */

	/* guard against empty function body; OK only if void return type */
	if (queryTreeList == NIL)
	{
		if (rettype != VOIDOID)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),