Remove the obsolete WITH clause of CREATE FUNCTION.

This clause was superseded by SQL-standard syntax back in 7.3.
We've kept it around for backwards-compatibility purposes ever since;
but 15 years seems like long enough for that, especially seeing that
there are undocumented weirdnesses in how it interacts with the
SQL-standard syntax for specifying the same options.

Michael Paquier, per an observation by Daniel Gustafsson;
some small cosmetic adjustments to nearby code by me.

Discussion: https://postgr.es/m/20180115022748.GB1724@paquier.xyz

Author: tglsfdc

doc/src/sgml/ref/create_function.sgml

@@ -37,7 +37,6 @@ CREATE [ OR REPLACE ] FUNCTION
     | AS '<replaceable class="parameter">definition</replaceable>'
     | AS '<replaceable class="parameter">obj_file</replaceable>', '<replaceable class="parameter">link_symbol</replaceable>'
   } ...
-    [ WITH ( <replaceable class="parameter">attribute</replaceable> [, ...] ) ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -560,41 +559,6 @@ CREATE [ OR REPLACE ] FUNCTION
      </listitem>
     </varlistentry>
 
-    <varlistentry>
-     <term><replaceable class="parameter">attribute</replaceable></term>
-
-     <listitem>
-      <para>
-       The historical way to specify optional pieces of information
-       about the function.  The following attributes can appear here:
-
-      <variablelist>
-       <varlistentry>
-        <term><literal>isStrict</literal></term>
-        <listitem>
-         <para>
-          Equivalent to <literal>STRICT</literal> or <literal>RETURNS NULL ON NULL INPUT</literal>.
-         </para>
-        </listitem>
-       </varlistentry>
-
-       <varlistentry>
-        <term><literal>isCachable</literal></term>
-        <listitem>
-         <para><literal>isCachable</literal> is an obsolete equivalent of
-          <literal>IMMUTABLE</literal>; it's still accepted for
-          backwards-compatibility reasons.
-         </para>
-        </listitem>
-       </varlistentry>
-
-      </variablelist>
-
-      Attribute names are not case-sensitive.
-     </para>
-    </listitem>
-   </varlistentry>
-
    </variablelist>
 
    <para>

src/backend/commands/functioncmds.c

@@ -637,21 +637,21 @@ update_proconfig_value(ArrayType *a, List *set_items)
  * attributes.
  */
 static void
-compute_attributes_sql_style(ParseState *pstate,
-							 bool is_procedure,
-							 List *options,
-							 List **as,
-							 char **language,
-							 Node **transform,
-							 bool *windowfunc_p,
-							 char *volatility_p,
-							 bool *strict_p,
-							 bool *security_definer,
-							 bool *leakproof_p,
-							 ArrayType **proconfig,
-							 float4 *procost,
-							 float4 *prorows,
-							 char *parallel_p)
+compute_function_attributes(ParseState *pstate,
+							bool is_procedure,
+							List *options,
+							List **as,
+							char **language,
+							Node **transform,
+							bool *windowfunc_p,
+							char *volatility_p,
+							bool *strict_p,
+							bool *security_definer,
+							bool *leakproof_p,
+							ArrayType **proconfig,
+							float4 *procost,
+							float4 *prorows,
+							char *parallel_p)
 {
 	ListCell   *option;
 	DefElem    *as_item = NULL;
@@ -789,59 +789,6 @@ compute_attributes_sql_style(ParseState *pstate,
 }
 
 
-/*-------------
- *	 Interpret the parameters *parameters and return their contents via
- *	 *isStrict_p and *volatility_p.
- *
- *	These parameters supply optional information about a function.
- *	All have defaults if not specified. Parameters:
- *
- *	 * 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.
- *------------
- */
-static void
-compute_attributes_with_style(ParseState *pstate, bool is_procedure, List *parameters, bool *isStrict_p, char *volatility_p)
-{
-	ListCell   *pl;
-
-	foreach(pl, parameters)
-	{
-		DefElem    *param = (DefElem *) lfirst(pl);
-
-		if (pg_strcasecmp(param->defname, "isstrict") == 0)
-		{
-			if (is_procedure)
-				ereport(ERROR,
-						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
-						 errmsg("invalid attribute in procedure definition"),
-						 parser_errposition(pstate, param->location)));
-			*isStrict_p = defGetBoolean(param);
-		}
-		else if (pg_strcasecmp(param->defname, "iscachable") == 0)
-		{
-			/* obsolete spelling of isImmutable */
-			if (is_procedure)
-				ereport(ERROR,
-						(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
-						 errmsg("invalid attribute in procedure definition"),
-						 parser_errposition(pstate, param->location)));
-			if (defGetBoolean(param))
-				*volatility_p = PROVOLATILE_IMMUTABLE;
-		}
-		else
-			ereport(WARNING,
-					(errcode(ERRCODE_SYNTAX_ERROR),
-					 errmsg("unrecognized function attribute \"%s\" ignored",
-							param->defname),
-					 parser_errposition(pstate, param->location)));
-	}
-}
-
-
 /*
  * For a dynamically linked C language object, the form of the clause is
  *
@@ -909,7 +856,7 @@ interpret_AS_clause(Oid languageOid, const char *languageName,
 
 /*
  * CreateFunction
- *	 Execute a CREATE FUNCTION utility statement.
+ *	 Execute a CREATE FUNCTION (or CREATE PROCEDURE) utility statement.
  */
 ObjectAddress
 CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
@@ -957,7 +904,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 		aclcheck_error(aclresult, OBJECT_SCHEMA,
 					   get_namespace_name(namespaceId));
 
-	/* default attributes */
+	/* Set default attributes */
 	isWindowFunc = false;
 	isStrict = false;
 	security = false;
@@ -968,14 +915,14 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 	prorows = -1;				/* indicates not set */
 	parallel = PROPARALLEL_UNSAFE;
 
-	/* override attributes from explicit list */
-	compute_attributes_sql_style(pstate,
-								 stmt->is_procedure,
-								 stmt->options,
-								 &as_clause, &language, &transformDefElem,
-								 &isWindowFunc, &volatility,
-								 &isStrict, &security, &isLeakProof,
-								 &proconfig, &procost, &prorows, &parallel);
+	/* Extract non-default attributes from stmt->options list */
+	compute_function_attributes(pstate,
+								stmt->is_procedure,
+								stmt->options,
+								&as_clause, &language, &transformDefElem,
+								&isWindowFunc, &volatility,
+								&isStrict, &security, &isLeakProof,
+								&proconfig, &procost, &prorows, &parallel);
 
 	/* Look up the language and validate permissions */
 	languageTuple = SearchSysCache1(LANGNAME, PointerGetDatum(language));
@@ -1107,8 +1054,6 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 		trftypes = NULL;
 	}
 
-	compute_attributes_with_style(pstate, stmt->is_procedure, stmt->withClause, &isStrict, &volatility);
-
 	interpret_AS_clause(languageOid, language, funcname, as_clause,
 						&prosrc_str, &probin_str);
 
@@ -2269,7 +2214,7 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 	FuncExpr   *fexpr;
 	int			nargs;
 	int			i;
-	AclResult   aclresult;
+	AclResult	aclresult;
 	FmgrInfo	flinfo;
 	FunctionCallInfoData fcinfo;
 	CallContext *callcontext;
@@ -2329,7 +2274,7 @@ ExecuteCallStmt(ParseState *pstate, CallStmt *stmt, bool atomic)
 	InitFunctionCallInfoData(fcinfo, &flinfo, nargs, fexpr->inputcollid, (Node *) callcontext, NULL);
 
 	i = 0;
-	foreach (lc, fexpr->args)
+	foreach(lc, fexpr->args)
 	{
 		EState	   *estate;
 		ExprState  *exprstate;

src/backend/nodes/copyfuncs.c

@@ -3217,7 +3217,7 @@ _copyClosePortalStmt(const ClosePortalStmt *from)
 static CallStmt *
 _copyCallStmt(const CallStmt *from)
 {
-	CallStmt *newnode = makeNode(CallStmt);
+	CallStmt   *newnode = makeNode(CallStmt);
 
 	COPY_NODE_FIELD(funccall);
 
@@ -3422,13 +3422,12 @@ _copyCreateFunctionStmt(const CreateFunctionStmt *from)
 {
 	CreateFunctionStmt *newnode = makeNode(CreateFunctionStmt);
 
+	COPY_SCALAR_FIELD(is_procedure);
 	COPY_SCALAR_FIELD(replace);
 	COPY_NODE_FIELD(funcname);
 	COPY_NODE_FIELD(parameters);
 	COPY_NODE_FIELD(returnType);
-	COPY_SCALAR_FIELD(is_procedure);
 	COPY_NODE_FIELD(options);
-	COPY_NODE_FIELD(withClause);
 
 	return newnode;
 }

src/backend/nodes/equalfuncs.c

@@ -1370,13 +1370,12 @@ _equalCreateStatsStmt(const CreateStatsStmt *a, const CreateStatsStmt *b)
 static bool
 _equalCreateFunctionStmt(const CreateFunctionStmt *a, const CreateFunctionStmt *b)
 {
+	COMPARE_SCALAR_FIELD(is_procedure);
 	COMPARE_SCALAR_FIELD(replace);
 	COMPARE_NODE_FIELD(funcname);
 	COMPARE_NODE_FIELD(parameters);
 	COMPARE_NODE_FIELD(returnType);
-	COMPARE_SCALAR_FIELD(is_procedure);
 	COMPARE_NODE_FIELD(options);
-	COMPARE_NODE_FIELD(withClause);
 
 	return true;
 }

src/backend/parser/gram.y

@@ -7506,51 +7506,51 @@ opt_nulls_order: NULLS_LA FIRST_P			{ $$ = SORTBY_NULLS_FIRST; }
 
 CreateFunctionStmt:
 			CREATE opt_or_replace FUNCTION func_name func_args_with_defaults
-			RETURNS func_return createfunc_opt_list opt_definition
+			RETURNS func_return createfunc_opt_list
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
+					n->is_procedure = false;
 					n->replace = $2;
 					n->funcname = $4;
 					n->parameters = $5;
 					n->returnType = $7;
 					n->options = $8;
-					n->withClause = $9;
 					$$ = (Node *)n;
 				}
 			| CREATE opt_or_replace FUNCTION func_name func_args_with_defaults
-			  RETURNS TABLE '(' table_func_column_list ')' createfunc_opt_list opt_definition
+			  RETURNS TABLE '(' table_func_column_list ')' createfunc_opt_list
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
+					n->is_procedure = false;
 					n->replace = $2;
 					n->funcname = $4;
 					n->parameters = mergeTableFuncParameters($5, $9);
 					n->returnType = TableFuncTypeName($9);
 					n->returnType->location = @7;
 					n->options = $11;
-					n->withClause = $12;
 					$$ = (Node *)n;
 				}
 			| CREATE opt_or_replace FUNCTION func_name func_args_with_defaults
-			  createfunc_opt_list opt_definition
+			  createfunc_opt_list
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
+					n->is_procedure = false;
 					n->replace = $2;
 					n->funcname = $4;
 					n->parameters = $5;
 					n->returnType = NULL;
 					n->options = $6;
-					n->withClause = $7;
 					$$ = (Node *)n;
 				}
 			| CREATE opt_or_replace PROCEDURE func_name func_args_with_defaults
 			  createfunc_opt_list
 				{
 					CreateFunctionStmt *n = makeNode(CreateFunctionStmt);
+					n->is_procedure = true;
 					n->replace = $2;
 					n->funcname = $4;
 					n->parameters = $5;
 					n->returnType = NULL;
-					n->is_procedure = true;
 					n->options = $6;
 					$$ = (Node *)n;
 				}

src/include/nodes/parsenodes.h

@@ -2735,13 +2735,12 @@ typedef struct CreateStatsStmt
 typedef struct CreateFunctionStmt
 {
 	NodeTag		type;
+	bool		is_procedure;	/* it's really CREATE PROCEDURE */
 	bool		replace;		/* T => replace if already exists */
 	List	   *funcname;		/* qualified name of function to create */
 	List	   *parameters;		/* a list of FunctionParameter */
 	TypeName   *returnType;		/* the return type */
-	bool		is_procedure;
 	List	   *options;		/* a list of DefElem */
-	List	   *withClause;		/* a list of DefElem */
 } CreateFunctionStmt;
 
 typedef enum FunctionParameterMode