/*-------------------------------------------------------------------------
*
* functioncmds.c
*
* Routines for CREATE and DROP FUNCTION commands
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/functioncmds.c,v 1.3 2002/04/27 03:45:01 tgl Exp $
*
* DESCRIPTION
* These routines take the parse tree and pick out the
* appropriate arguments/flags, and pass the results to the
* corresponding "FooDefine" routines (in src/catalog) that do
* the actual catalog-munging. These routines also verify permission
* of the user to execute the command.
*
* NOTES
* These things must be defined and committed in the following order:
* "create function":
* input/output, recv/send procedures
* "create type":
* type
* "create operator":
* operators
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/namespace.h"
#include "catalog/pg_language.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "miscadmin.h"
#include "optimizer/cost.h"
#include "parser/parse_func.h"
#include "parser/parse_type.h"
#include "utils/acl.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
/*
* Examine the "returns" clause returnType of the CREATE FUNCTION statement
* and return information about it as *prorettype_p and *returnsSet.
*
* This is more complex than the average typename lookup because we want to
* allow a shell type to be used, or even created if the specified return type
* doesn't exist yet. (Without this, there's no way to define the I/O procs
* for a new type.) But SQL function creation won't cope, so error out if
* the target language is SQL.
*/
static void
compute_return_type(TypeName *returnType, Oid languageOid,
Oid *prorettype_p, bool *returnsSet_p)
{
Oid rettype;
rettype = LookupTypeName(returnType);
if (OidIsValid(rettype))
{
if (!get_typisdefined(rettype))
{
if (languageOid == SQLlanguageId)
elog(ERROR, "SQL functions cannot return shell types");
else
elog(WARNING, "Return type \"%s\" is only a shell",
TypeNameToString(returnType));
}
}
else
{
char *typnam = TypeNameToString(returnType);
if (strcmp(typnam, "opaque") == 0)
rettype = InvalidOid;
else
{
Oid namespaceId;
AclResult aclresult;
char *typname;
if (languageOid == SQLlanguageId)
elog(ERROR, "Type \"%s\" does not exist", typnam);
elog(WARNING, "ProcedureCreate: type %s is not yet defined",
typnam);
namespaceId = QualifiedNameGetCreationNamespace(returnType->names,
&typname);
aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_namespace_name(namespaceId));
rettype = TypeShellMake(typname, namespaceId);
if (!OidIsValid(rettype))
elog(ERROR, "could not create type %s", typnam);
}
}
*prorettype_p = rettype;
*returnsSet_p = returnType->setof;
}
/*
* Interpret the argument-types list of the CREATE FUNCTION statement.
*/
static int
compute_parameter_types(List *argTypes, Oid languageOid,
Oid *parameterTypes)
{
int parameterCount = 0;
List *x;
MemSet(parameterTypes, 0, FUNC_MAX_ARGS * sizeof(Oid));
foreach(x, argTypes)
{
TypeName *t = (TypeName *) lfirst(x);
Oid toid;
if (parameterCount >= FUNC_MAX_ARGS)
elog(ERROR, "functions cannot have more than %d arguments",
FUNC_MAX_ARGS);
toid = LookupTypeName(t);
if (OidIsValid(toid))
{
if (!get_typisdefined(toid))
elog(WARNING, "Argument type \"%s\" is only a shell",
TypeNameToString(t));
}
else
{
char *typnam = TypeNameToString(t);
if (strcmp(typnam, "opaque") == 0)
{
if (languageOid == SQLlanguageId)
elog(ERROR, "SQL functions cannot have arguments of type \"opaque\"");
toid = InvalidOid;
}
else
elog(ERROR, "Type \"%s\" does not exist", typnam);
}
if (t->setof)
elog(ERROR, "functions cannot accept set arguments");
parameterTypes[parameterCount++] = toid;
}
return parameterCount;
}
/*-------------
* Interpret the parameters *parameters and return their contents as
* *byte_pct_p, etc.
*
* These parameters supply optional information about a function.
* All have defaults if not specified.
*
* Note: currently, only three of these parameters actually do anything:
*
* * isImplicit means the function may be used as an implicit type
* coercion.
*
* * isStrict means the function should not be called when any NULL
* inputs are present; instead a NULL result value should be assumed.
*
* * volatility tells the optimizer whether the function's result can
* be assumed to be repeatable over multiple evaluations.
*
* The other four parameters are not used anywhere. They used to be
* used in the "expensive functions" optimizer, but that's been dead code
* for a long time.
*------------
*/
static void
compute_full_attributes(List *parameters,
int32 *byte_pct_p, int32 *perbyte_cpu_p,
int32 *percall_cpu_p, int32 *outin_ratio_p,
bool *isImplicit_p, bool *isStrict_p,
char *volatility_p)
{
List *pl;
/* the defaults */
*byte_pct_p = BYTE_PCT;
*perbyte_cpu_p = PERBYTE_CPU;
*percall_cpu_p = PERCALL_CPU;
*outin_ratio_p = OUTIN_RATIO;
*isImplicit_p = false;
*isStrict_p = false;
*volatility_p = PROVOLATILE_VOLATILE;
foreach(pl, parameters)
{
DefElem *param = (DefElem *) lfirst(pl);
if (strcasecmp(param->defname, "implicitcoercion") == 0)
*isImplicit_p = true;
else if (strcasecmp(param->defname, "isstrict") == 0)
*isStrict_p = true;
else if (strcasecmp(param->defname, "isimmutable") == 0)
*volatility_p = PROVOLATILE_IMMUTABLE;
else if (strcasecmp(param->defname, "isstable") == 0)
*volatility_p = PROVOLATILE_STABLE;
else if (strcasecmp(param->defname, "isvolatile") == 0)
*volatility_p = PROVOLATILE_VOLATILE;
else if (strcasecmp(param->defname, "iscachable") == 0)
{
/* obsolete spelling of isImmutable */
*volatility_p = PROVOLATILE_IMMUTABLE;
}
else if (strcasecmp(param->defname, "trusted") == 0)
{
/*
* we don't have untrusted functions any more. The 4.2
* implementation is lousy anyway so I took it out. -ay 10/94
*/
elog(ERROR, "untrusted function has been decommissioned.");
}
else if (strcasecmp(param->defname, "byte_pct") == 0)
*byte_pct_p = (int) defGetNumeric(param);
else if (strcasecmp(param->defname, "perbyte_cpu") == 0)
*perbyte_cpu_p = (int) defGetNumeric(param);
else if (strcasecmp(param->defname, "percall_cpu") == 0)
*percall_cpu_p = (int) defGetNumeric(param);
else if (strcasecmp(param->defname, "outin_ratio") == 0)
*outin_ratio_p = (int) defGetNumeric(param);
else
elog(WARNING, "Unrecognized function attribute '%s' ignored",
param->defname);
}
}
/*
* For a dynamically linked C language object, the form of the clause is
*
* AS <object file name> [, <link symbol name> ]
*
* In all other cases
*
* AS <object reference, or sql code>
*
*/
static void
interpret_AS_clause(Oid languageOid, const char *languageName, const List *as,
char **prosrc_str_p, char **probin_str_p)
{
Assert(as != NIL);
if (languageOid == ClanguageId)
{
/*
* For "C" language, store the file name in probin and, when
* given, the link symbol name in prosrc.
*/
*probin_str_p = strVal(lfirst(as));
if (lnext(as) == NULL)
*prosrc_str_p = "-";
else
*prosrc_str_p = strVal(lsecond(as));
}
else
{
/* Everything else wants the given string in prosrc. */
*prosrc_str_p = strVal(lfirst(as));
*probin_str_p = "-";
if (lnext(as) != NIL)
elog(ERROR, "CREATE FUNCTION: only one AS item needed for %s language",
languageName);
}
}
/*
* CreateFunction
* Execute a CREATE FUNCTION utility statement.
*/
void
CreateFunction(ProcedureStmt *stmt)
{
char *probin_str;
char *prosrc_str;
Oid prorettype;
bool returnsSet;
char languageName[NAMEDATALEN];
Oid languageOid;
char *funcname;
Oid namespaceId;
AclResult aclresult;
int parameterCount;
Oid parameterTypes[FUNC_MAX_ARGS];
int32 byte_pct,
perbyte_cpu,
percall_cpu,
outin_ratio;
bool isImplicit,
isStrict;
char volatility;
HeapTuple languageTuple;
Form_pg_language languageStruct;
/* Convert list of names to a name and namespace */
namespaceId = QualifiedNameGetCreationNamespace(stmt->funcname,
&funcname);
/* Check we have creation rights in target namespace */
aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_namespace_name(namespaceId));
/* Convert language name to canonical case */
case_translate_language_name(stmt->language, languageName);
/* Look up the language and validate permissions */
languageTuple = SearchSysCache(LANGNAME,
PointerGetDatum(languageName),
0, 0, 0);
if (!HeapTupleIsValid(languageTuple))
elog(ERROR, "language \"%s\" does not exist", languageName);
languageOid = languageTuple->t_data->t_oid;
languageStruct = (Form_pg_language) GETSTRUCT(languageTuple);
if (languageStruct->lanpltrusted)
{
/* if trusted language, need USAGE privilege */
AclResult aclresult;
aclresult = pg_language_aclcheck(languageOid, GetUserId(), ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, NameStr(languageStruct->lanname));
}
else
{
/* if untrusted language, must be superuser */
if (!superuser())
aclcheck_error(ACLCHECK_NO_PRIV, NameStr(languageStruct->lanname));
}
ReleaseSysCache(languageTuple);
/*
* Convert remaining parameters of CREATE to form wanted by
* ProcedureCreate.
*/
compute_return_type(stmt->returnType, languageOid,
&prorettype, &returnsSet);
parameterCount = compute_parameter_types(stmt->argTypes, languageOid,
parameterTypes);
compute_full_attributes(stmt->withClause,
&byte_pct, &perbyte_cpu, &percall_cpu,
&outin_ratio, &isImplicit, &isStrict,
&volatility);
interpret_AS_clause(languageOid, languageName, stmt->as,
&prosrc_str, &probin_str);
/*
* And now that we have all the parameters, and know we're permitted
* to do so, go ahead and create the function.
*/
ProcedureCreate(funcname,
namespaceId,
stmt->replace,
returnsSet,
prorettype,
languageOid,
prosrc_str, /* converted to text later */
probin_str, /* converted to text later */
false, /* not an aggregate */
true, /* (obsolete "trusted") */
isImplicit,
isStrict,
volatility,
byte_pct,
perbyte_cpu,
percall_cpu,
outin_ratio,
parameterCount,
parameterTypes);
}
/*
* RemoveFunction
* Deletes a function.
*
* Exceptions:
* BadArg if name is invalid.
* "ERROR" if function nonexistent.
* ...
*/
void
RemoveFunction(List *functionName, /* function name to be removed */
List *argTypes) /* list of TypeName nodes */
{
Oid funcOid;
Relation relation;
HeapTuple tup;
funcOid = LookupFuncNameTypeNames(functionName, argTypes,
true, "RemoveFunction");
relation = heap_openr(ProcedureRelationName, RowExclusiveLock);
tup = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcOid),
0, 0, 0);
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "RemoveFunction: couldn't find tuple for function %s",
NameListToString(functionName));
/* Permission check: must own func or its namespace */
if (!pg_proc_ownercheck(funcOid, GetUserId()) &&
!pg_namespace_ownercheck(((Form_pg_proc) GETSTRUCT(tup))->pronamespace,
GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, NameListToString(functionName));
if (((Form_pg_proc) GETSTRUCT(tup))->proisagg)
elog(ERROR, "RemoveFunction: function '%s' is an aggregate"
"\n\tUse DROP AGGREGATE to remove it",
NameListToString(functionName));
if (((Form_pg_proc) GETSTRUCT(tup))->prolang == INTERNALlanguageId)
{
/* "Helpful" WARNING when removing a builtin function ... */
elog(WARNING, "Removing built-in function \"%s\"",
NameListToString(functionName));
}
/* Delete any comments associated with this function */
DeleteComments(funcOid, RelationGetRelid(relation));
simple_heap_delete(relation, &tup->t_self);
ReleaseSysCache(tup);
heap_close(relation, RowExclusiveLock);
}