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.

2 files changed, 44 insertions, 4 deletions

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 */