Add optional "validator" function to languages that can validate the

function body (and other properties) as a function in the language
is created.  This generalizes ad hoc code that already existed for
the built-in languages.

The validation now happens after the pg_proc tuple of the new function
is created, so it is possible to define recursive SQL functions.

Add some regression test cases that cover bogus function definition
attempts.

9 files changed, 199 insertions, 81 deletions

diff --git a/src/backend/catalog/pg_aggregate.c b/src/backend/catalog/pg_aggregate.c
index 1853acda73c..3a3d749e19d 100644
--- a/src/backend/catalog/pg_aggregate.c
+++ b/src/backend/catalog/pg_aggregate.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_aggregate.c,v 1.47 2002/05/21 22:05:54 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_aggregate.c,v 1.48 2002/05/22 17:20:58 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -136,6 +136,7 @@ AggregateCreate(const char *aggName,
 							  false,		/* doesn't return a set */
 							  finaltype,	/* returnType */
 							  INTERNALlanguageId,	/* languageObjectId */
+							  0,
 							  "aggregate_dummy",	/* placeholder proc */
 							  "-",			/* probin */
 							  true,			/* isAgg */
diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index 4d656d98ba2..e7421ef2077 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_proc.c,v 1.73 2002/05/21 22:05:54 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_proc.c,v 1.74 2002/05/22 17:20:58 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,6 +20,7 @@
 #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"
@@ -32,6 +33,9 @@
 
 
 static void checkretval(Oid rettype, List *queryTreeList);
+Datum fmgr_internal_validator(PG_FUNCTION_ARGS);
+Datum fmgr_c_validator(PG_FUNCTION_ARGS);
+Datum fmgr_sql_validator(PG_FUNCTION_ARGS);
 
 
 /* ----------------------------------------------------------------
@@ -45,6 +49,7 @@ ProcedureCreate(const char *procedureName,
 				bool returnsSet,
 				Oid returnType,
 				Oid languageObjectId,
+				Oid languageValidator,
 				const char *prosrc,
 				const char *probin,
 				bool isAgg,
@@ -66,7 +71,6 @@ ProcedureCreate(const char *procedureName,
 	char		nulls[Natts_pg_proc];
 	Datum		values[Natts_pg_proc];
 	char		replaces[Natts_pg_proc];
-	List	   *querytree_list;
 	Oid			typev[FUNC_MAX_ARGS];
 	Oid			relid;
 	NameData	procname;
@@ -126,12 +130,6 @@ ProcedureCreate(const char *procedureName,
 		}
 	}
 
-	if (!OidIsValid(returnType))
-	{
-		if (languageObjectId == SQLlanguageId)
-			elog(ERROR, "SQL functions cannot return type \"opaque\"");
-	}
-
 	/*
 	 * don't allow functions of complex types that have the same name as
 	 * existing attributes of the type
@@ -142,65 +140,6 @@ ProcedureCreate(const char *procedureName,
 		elog(ERROR, "method %s already an attribute of type %s",
 			 procedureName, format_type_be(typev[0]));
 
-	/*
-	 * If this is a postquel procedure, we parse it here in order to be
-	 * sure that it contains no syntax errors.	We should store the plan
-	 * in an Inversion file for use later, but for now, we just store the
-	 * procedure's text in the prosrc attribute.
-	 */
-
-	if (languageObjectId == SQLlanguageId)
-	{
-		querytree_list = pg_parse_and_rewrite((char *) prosrc,
-											  typev,
-											  parameterCount);
-		/* typecheck return value */
-		checkretval(returnType, querytree_list);
-	}
-
-	/*
-	 * If this is an internal procedure, check that the given internal
-	 * function name (the 'prosrc' value) is a known builtin function.
-	 *
-	 * NOTE: in Postgres versions before 6.5, the SQL name of the created
-	 * function could not be different from the internal name, and
-	 * 'prosrc' wasn't used.  So there is code out there that does CREATE
-	 * FUNCTION xyz AS '' LANGUAGE 'internal'.	To preserve some modicum
-	 * of backwards compatibility, accept an empty 'prosrc' value as
-	 * meaning the supplied SQL function name.
-	 */
-	if (languageObjectId == INTERNALlanguageId)
-	{
-		if (strlen(prosrc) == 0)
-			prosrc = procedureName;
-		if (fmgr_internal_function((char *) prosrc) == InvalidOid)
-			elog(ERROR,
-				 "there is no built-in function named \"%s\"",
-				 prosrc);
-	}
-
-	/*
-	 * If this is a dynamically loadable procedure, make sure that the
-	 * library file exists, is loadable, and contains the specified link
-	 * symbol.	Also check for a valid function information record.
-	 *
-	 * We used to perform these checks only when the function was first
-	 * called, but it seems friendlier to verify the library's validity at
-	 * CREATE FUNCTION time.
-	 */
-	if (languageObjectId == ClanguageId)
-	{
-		void	   *libraryhandle;
-
-		/* If link symbol is specified as "-", substitute procedure name */
-		if (strcmp(prosrc, "-") == 0)
-			prosrc = procedureName;
-		(void) load_external_function((char *) probin,
-									  (char *) prosrc,
-									  true,
-									  &libraryhandle);
-		(void) fetch_finfo_record(libraryhandle, (char *) prosrc);
-	}
 
 	/*
 	 * All seems OK; prepare the data to be inserted into pg_proc.
@@ -316,6 +255,14 @@ ProcedureCreate(const char *procedureName,
 
 	heap_close(rel, RowExclusiveLock);
 
+	/* Verify function body */
+	if (OidIsValid(languageValidator))
+	{
+		/* Advance command counter so recursive functions can be defined */
+		CommandCounterIncrement();
+		OidFunctionCall1(languageValidator, retval);
+	}
+
 	return retval;
 }
 
@@ -454,3 +401,122 @@ checkretval(Oid rettype, List *queryTreeList)
 
 	heap_close(reln, AccessShareLock);
 }
+
+
+
+/*
+ * Validator for internal functions
+ *
+ * Check that the given internal function name (the "prosrc" value) is
+ * a known builtin function.
+ */
+Datum
+fmgr_internal_validator(PG_FUNCTION_ARGS)
+{
+	Oid			funcoid = PG_GETARG_OID(0);
+	HeapTuple	tuple;
+	Form_pg_proc proc;
+	bool		isnull;
+	Datum		tmp;
+	char	   *prosrc;
+
+	tuple = SearchSysCache(PROCOID, funcoid, 0, 0, 0);
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup of function %u failed", funcoid);
+	proc = (Form_pg_proc) GETSTRUCT(tuple);
+
+	tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
+	if (isnull)
+		elog(ERROR, "null prosrc");
+	prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
+
+	if (fmgr_internal_function(prosrc) == InvalidOid)
+		elog(ERROR, "there is no built-in function named \"%s\"", prosrc);
+
+	ReleaseSysCache(tuple);
+	PG_RETURN_BOOL(true);
+}
+
+
+
+/*
+ * Validator for C language functions
+ *
+ * Make sure that the library file exists, is loadable, and contains
+ * the specified link symbol. Also check for a valid function
+ * information record.
+ */
+Datum
+fmgr_c_validator(PG_FUNCTION_ARGS)
+{
+	Oid			funcoid = PG_GETARG_OID(0);
+	void	   *libraryhandle;
+	HeapTuple	tuple;
+	Form_pg_proc proc;
+	bool		isnull;
+	Datum		tmp;
+	char	   *prosrc;
+	char	   *probin;
+
+	tuple = SearchSysCache(PROCOID, funcoid, 0, 0, 0);
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup of function %u failed", funcoid);
+	proc = (Form_pg_proc) GETSTRUCT(tuple);
+
+	tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
+	if (isnull)
+		elog(ERROR, "null prosrc");
+	prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
+
+	tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_probin, &isnull);
+	if (isnull)
+		elog(ERROR, "null probin");
+	probin = DatumGetCString(DirectFunctionCall1(textout, tmp));
+	
+	(void) load_external_function(probin, prosrc, true, &libraryhandle);
+	(void) fetch_finfo_record(libraryhandle, prosrc);
+
+	ReleaseSysCache(tuple);
+	PG_RETURN_BOOL(true);
+}
+
+
+
+/*
+ * Validator for SQL language functions
+ *
+ * Parse it here in order to be sure that it contains no syntax
+ * errors.
+ */
+Datum
+fmgr_sql_validator(PG_FUNCTION_ARGS)
+{
+	Oid			funcoid = PG_GETARG_OID(0);
+	HeapTuple	tuple;
+	Form_pg_proc proc;
+	List	   *querytree_list;
+	bool		isnull;
+	Datum		tmp;
+	char	   *prosrc;
+
+	tuple = SearchSysCache(PROCOID, funcoid, 0, 0, 0);
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup of function %u failed", funcoid);
+
+	proc = (Form_pg_proc) GETSTRUCT(tuple);
+
+	if (!OidIsValid(proc->prorettype))
+			elog(ERROR, "SQL functions cannot return type \"opaque\"");
+
+	tmp = SysCacheGetAttr(PROCOID, tuple, Anum_pg_proc_prosrc, &isnull);
+	if (isnull)
+		elog(ERROR, "null prosrc");
+
+	prosrc = DatumGetCString(DirectFunctionCall1(textout, tmp));
+
+	querytree_list = pg_parse_and_rewrite(prosrc, proc->proargtypes, proc->pronargs);
+	checkretval(proc->prorettype, querytree_list);
+
+	ReleaseSysCache(tuple);
+	PG_RETURN_BOOL(true);
+}
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 06870b0d3d2..a619a71b435 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/functioncmds.c,v 1.5 2002/05/18 13:47:59 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/functioncmds.c,v 1.6 2002/05/22 17:20:58 petere Exp $
  *
  * DESCRIPTION
  *	  These routines take the parse tree and pick out the
@@ -388,6 +388,7 @@ CreateFunction(CreateFunctionStmt *stmt)
 	char	   *language;
 	char		languageName[NAMEDATALEN];
 	Oid			languageOid;
+	Oid			languageValidator;
 	char	   *funcname;
 	Oid			namespaceId;
 	AclResult	aclresult;
@@ -457,6 +458,8 @@ CreateFunction(CreateFunctionStmt *stmt)
 			aclcheck_error(ACLCHECK_NO_PRIV, NameStr(languageStruct->lanname));
 	}
 
+	languageValidator = languageStruct->lanvalidator;
+
 	ReleaseSysCache(languageTuple);
 
 	/*
@@ -477,6 +480,28 @@ CreateFunction(CreateFunctionStmt *stmt)
 	interpret_AS_clause(languageOid, languageName, as_clause,
 						&prosrc_str, &probin_str);
 
+	if (languageOid == INTERNALlanguageId)
+	{
+		/*
+		 * In PostgreSQL versions before 6.5, the SQL name of the
+		 * created function could not be different from the internal
+		 * name, and "prosrc" wasn't used.  So there is code out there
+		 * that does CREATE FUNCTION xyz AS '' LANGUAGE 'internal'.
+		 * To preserve some modicum of backwards compatibility, accept
+		 * an empty "prosrc" value as meaning the supplied SQL
+		 * function name.
+		 */
+		if (strlen(prosrc_str) == 0)
+			prosrc_str = funcname;
+	}
+
+	if (languageOid == ClanguageId)
+	{
+		/* If link symbol is specified as "-", substitute procedure name */
+		if (strcmp(prosrc_str, "-") == 0)
+			prosrc_str = funcname;
+	}
+
 	/*
 	 * And now that we have all the parameters, and know we're permitted
 	 * to do so, go ahead and create the function.
@@ -487,6 +512,7 @@ CreateFunction(CreateFunctionStmt *stmt)
 					returnsSet,
 					prorettype,
 					languageOid,
+					languageValidator,
 					prosrc_str, /* converted to text later */
 					probin_str, /* converted to text later */
 					false,		/* not an aggregate */
diff --git a/src/backend/commands/proclang.c b/src/backend/commands/proclang.c
index 6cabbf0ec13..626c05f59cd 100644
--- a/src/backend/commands/proclang.c
+++ b/src/backend/commands/proclang.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/proclang.c,v 1.32 2002/05/21 22:05:54 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/proclang.c,v 1.33 2002/05/22 17:20:58 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,6 +21,7 @@
 #include "catalog/namespace.h"
 #include "catalog/pg_language.h"
 #include "catalog/pg_proc.h"
+#include "catalog/pg_type.h"
 #include "commands/proclang.h"
 #include "commands/defrem.h"
 #include "fmgr.h"
@@ -39,7 +40,7 @@ void
 CreateProceduralLanguage(CreatePLangStmt *stmt)
 {
 	char		languageName[NAMEDATALEN];
-	Oid			procOid;
+	Oid			procOid, valProcOid;
 	Oid			typev[FUNC_MAX_ARGS];
 	char		nulls[Natts_pg_language];
 	Datum		values[Natts_pg_language];
@@ -76,9 +77,21 @@ CreateProceduralLanguage(CreatePLangStmt *stmt)
 		elog(ERROR, "PL handler function %s() doesn't exist",
 			 NameListToString(stmt->plhandler));
 	if (get_func_rettype(procOid) != InvalidOid)
-		elog(ERROR, "PL handler function %s() isn't of return type Opaque",
+		elog(ERROR, "PL handler function %s() does not return type \"opaque\"",
 			 NameListToString(stmt->plhandler));
 
+	/* validate the validator function */
+	if (stmt->plvalidator)
+	{
+		typev[0] = OIDOID;
+		valProcOid = LookupFuncName(stmt->plvalidator, 1, typev);
+		if (!OidIsValid(valProcOid))
+			elog(ERROR, "PL validator function %s(oid) doesn't exist",
+				 NameListToString(stmt->plvalidator));
+	}
+	else
+		valProcOid = 0;
+
 	/*
 	 * Insert the new language into pg_language
 	 */
@@ -93,6 +106,7 @@ CreateProceduralLanguage(CreatePLangStmt *stmt)
 	values[i++] = BoolGetDatum(true);	/* lanispl */
 	values[i++] = BoolGetDatum(stmt->pltrusted);
 	values[i++] = ObjectIdGetDatum(procOid);
+	values[i++] = ObjectIdGetDatum(valProcOid);
 	values[i++] = DirectFunctionCall1(textin,
 									  CStringGetDatum(stmt->plcompiler));
 	nulls[i] = 'n';				/* lanacl */
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 1f0cc11934f..5bc16dc9b82 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.187 2002/05/17 18:32:52 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.188 2002/05/22 17:20:58 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2418,6 +2418,7 @@ _copyCreatePLangStmt(CreatePLangStmt *from)
 	if (from->plname)
 		newnode->plname = pstrdup(from->plname);
 	Node_Copy(from, newnode, plhandler);
+	Node_Copy(from, newnode, plvalidator);
 	if (from->plcompiler)
 		newnode->plcompiler = pstrdup(from->plcompiler);
 	newnode->pltrusted = from->pltrusted;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index f48d6d033f4..b4f576fc881 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.134 2002/05/17 18:32:52 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.135 2002/05/22 17:20:59 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1252,6 +1252,8 @@ _equalCreatePLangStmt(CreatePLangStmt *a, CreatePLangStmt *b)
 		return false;
 	if (!equal(a->plhandler, b->plhandler))
 		return false;
+	if (!equal(a->plvalidator, b->plvalidator))
+		return false;
 	if (!equalstr(a->plcompiler, b->plcompiler))
 		return false;
 	if (a->pltrusted != b->pltrusted)
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 999910161d0..d1109b58a7e 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.318 2002/05/19 15:16:55 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.319 2002/05/22 17:20:59 petere Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -182,7 +182,7 @@ static void doNegateFloat(Value *v);
 		index_name, name, function_name, file_name
 
 %type <list>	func_name, handler_name, qual_Op, qual_all_Op, OptUseOp,
-		opt_class
+		opt_class, opt_validator
 
 %type <range>	qualified_name, OptConstrFromTable
 
@@ -375,7 +375,7 @@ static void doNegateFloat(Value *v);
 	UNENCRYPTED, UNION, UNIQUE, UNKNOWN, UNLISTEN, UNTIL, UPDATE, USAGE,
 	USER, USING,
 
-	VACUUM, VALID, VALUES, VARCHAR, VARYING, VERBOSE, VERSION, VIEW, VOLATILE,
+	VACUUM, VALID, VALIDATOR, VALUES, VARCHAR, VARYING, VERBOSE, VERSION, VIEW, VOLATILE,
 	WHEN, WHERE, WITH, WITHOUT, WORK,
 	YEAR_P,
 	ZONE
@@ -1835,12 +1835,13 @@ IntegerOnly:  Iconst
  *****************************************************************************/
 
 CreatePLangStmt:  CREATE opt_trusted opt_procedural LANGUAGE ColId_or_Sconst
-			HANDLER handler_name opt_lancompiler
+			HANDLER handler_name opt_validator opt_lancompiler
 			{
 				CreatePLangStmt *n = makeNode(CreatePLangStmt);
 				n->plname = $5;
 				n->plhandler = $7;
-				n->plcompiler = $8;
+				n->plvalidator = $8;
+				n->plcompiler = $9;
 				n->pltrusted = $2;
 				$$ = (Node *)n;
 			}
@@ -1864,6 +1865,10 @@ opt_lancompiler: LANCOMPILER Sconst { $$ = $2; }
 			| /*EMPTY*/			{ $$ = ""; }
 		;
 
+opt_validator: VALIDATOR handler_name { $$ = $2; }
+			| /*EMPTY*/ { $$ = NULL; }
+		;
+
 DropPLangStmt:  DROP opt_procedural LANGUAGE ColId_or_Sconst
 			{
 				DropPLangStmt *n = makeNode(DropPLangStmt);
@@ -6357,6 +6362,7 @@ unreserved_keyword:
 		| USAGE
 		| VACUUM
 		| VALID
+		| VALIDATOR
 		| VALUES
 		| VARYING
 		| VERSION
diff --git a/src/backend/parser/keywords.c b/src/backend/parser/keywords.c
index 36900127ea8..2cf91572a00 100644
--- a/src/backend/parser/keywords.c
+++ b/src/backend/parser/keywords.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.110 2002/05/17 18:32:52 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.111 2002/05/22 17:20:59 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -292,6 +292,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"using", USING},
 	{"vacuum", VACUUM},
 	{"valid", VALID},
+	{"validator", VALIDATOR},
 	{"values", VALUES},
 	{"varchar", VARCHAR},
 	{"varying", VARYING},
diff --git a/src/backend/utils/adt/sets.c b/src/backend/utils/adt/sets.c
index 298bdbdec82..e93ed50ff0a 100644
--- a/src/backend/utils/adt/sets.c
+++ b/src/backend/utils/adt/sets.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/sets.c,v 1.44 2002/05/18 13:47:59 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/sets.c,v 1.45 2002/05/22 17:21:00 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -58,6 +58,7 @@ SetDefine(char *querystr, Oid elemType)
 							 true,		/* returnsSet */
 							 elemType,	/* returnType */
 							 SQLlanguageId,	/* language */
+							 SQLvalidatorId,
 							 querystr,	/* prosrc */
 							 fileName,	/* probin */
 							 false,		/* not aggregate */