Change plpgsql compiler so that all elogs are trapped and a suitable

NOTICE added about error location (same method already used by plpgsql
executor).  Add checking of pg_proc row xmin/cmin to ensure that
plpgsql functions will be recompiled after they've been modified by
CREATE OR REPLACE FUNCTION.

6 files changed, 145 insertions, 110 deletions

diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y
index a2d37c3f99..a7da1710c1 100644
--- a/src/pl/plpgsql/src/gram.y
+++ b/src/pl/plpgsql/src/gram.y
@@ -4,7 +4,7 @@
  *						  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.26 2001/10/09 04:15:38 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.27 2001/10/09 15:59:56 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -507,10 +507,16 @@ decl_aliasitem	: T_WORD
 						plpgsql_ns_setlocal(false);
 						name = plpgsql_tolower(yytext);
 						if (name[0] != '$')
+						{
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "can only alias positional parameters");
+						}
 						nsi = plpgsql_ns_lookup(name, NULL);
 						if (nsi == NULL)
+						{
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "function has no parameter %s", name);
+						}
 
 						plpgsql_ns_setlocal(true);
 
@@ -585,14 +591,12 @@ decl_defval		: ';'
 						{
 							case 0:
 								plpgsql_error_lineno = lno;
-								plpgsql_comperrinfo();
 								elog(ERROR, "unexpected end of file");
 							case K_NULL:
 								if (yylex() != ';')
 								{
 									plpgsql_error_lineno = lno;
-									plpgsql_comperrinfo();
-									elog(ERROR, "expectec ; after NULL");
+									elog(ERROR, "expected ; after NULL");
 								}
 								free(expr);
 								plpgsql_dstring_free(&ds);
@@ -607,7 +611,6 @@ decl_defval		: ';'
 									if (tok == 0)
 									{
 										plpgsql_error_lineno = lno;
-										plpgsql_comperrinfo();
 										elog(ERROR, "unterminated default value");
 									}
 									if (plpgsql_SpaceScanned)
@@ -793,7 +796,7 @@ getdiag_target	: T_VARIABLE
 					{
 						if (yylval.var->isconst)
 						{
-							plpgsql_comperrinfo();
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "%s is declared CONSTANT; can not receive diagnostics", yylval.var->refname);
 						}
 						$$ = yylval.var->varno;
@@ -809,7 +812,7 @@ assign_var		: T_VARIABLE
 					{
 						if (yylval.var->isconst)
 						{
-							plpgsql_comperrinfo();
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "%s is declared CONSTANT", yylval.var->refname);
 						}
 						$$ = yylval.var->varno;
@@ -1045,7 +1048,6 @@ fori_lower		:
 									if (tok == 0)
 									{
 										plpgsql_error_lineno = lno;
-										plpgsql_comperrinfo();
 										elog(ERROR, "missing .. to terminate lower bound of for loop");
 									}
 									plpgsql_dstring_append(&ds, yytext);
@@ -1083,7 +1085,6 @@ stmt_fors		: opt_label K_FOR lno fors_target K_IN K_SELECT expr_until_loop loop_
 								new->row = (PLpgSQL_row *)$4;
 								break;
 							default:
-								plpgsql_comperrinfo();
 								elog(ERROR, "unknown dtype %d in stmt_fors", $4->dtype);
 						}
 						new->query = $7;
@@ -1113,7 +1114,6 @@ stmt_dynfors : opt_label K_FOR lno fors_target K_IN K_EXECUTE expr_until_loop lo
 								new->row = (PLpgSQL_row *)$4;
 								break;
 							default:
-								plpgsql_comperrinfo();
 								elog(ERROR, "unknown dtype %d in stmt_dynfors", $4->dtype);
 						}
 						new->query = $7;
@@ -1339,7 +1339,7 @@ stmt_open		: K_OPEN lno cursor_varptr
 
 							if (tok != K_FOR)
 							{
-								plpgsql_comperrinfo();
+								plpgsql_error_lineno = $2;
 								elog(ERROR, "syntax error at \"%s\" - expected FOR to open a reference cursor", yytext);
 							}
 
@@ -1355,7 +1355,7 @@ stmt_open		: K_OPEN lno cursor_varptr
 									break;
 
 								default:
-									plpgsql_comperrinfo();
+									plpgsql_error_lineno = $2;
 									elog(ERROR, "syntax error at \"%s\"", yytext);
 							}
 
@@ -1370,7 +1370,7 @@ stmt_open		: K_OPEN lno cursor_varptr
 
 								if (tok != '(')
 								{
-									plpgsql_comperrinfo();
+									plpgsql_error_lineno = yylineno;
 									elog(ERROR, "cursor %s has arguments", $3->refname);
 								}
 
@@ -1384,7 +1384,7 @@ stmt_open		: K_OPEN lno cursor_varptr
 								--cp;
 								if (*cp != ')')
 								{
-									plpgsql_comperrinfo();
+									plpgsql_error_lineno = yylineno;
 									elog(ERROR, "missing )");
 								}
 								*cp = '\0';
@@ -1395,13 +1395,13 @@ stmt_open		: K_OPEN lno cursor_varptr
 
 								if (tok == '(')
 								{
-									plpgsql_comperrinfo();
+									plpgsql_error_lineno = yylineno;
 									elog(ERROR, "cursor %s has no arguments", $3->refname);
 								}
 								
 								if (tok != ';')
 								{
-									plpgsql_comperrinfo();
+									plpgsql_error_lineno = yylineno;
 									elog(ERROR, "syntax error at \"%s\"", yytext);
 								}
 							}
@@ -1440,7 +1440,7 @@ cursor_varptr	: T_VARIABLE
 					{
 						if (yylval.var->datatype->typoid != REFCURSOROID)
 						{
-							plpgsql_comperrinfo();
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "%s must be of type cursor or refcursor", yylval.var->refname);
 						}
 						$$ = yylval.var;
@@ -1451,7 +1451,7 @@ cursor_variable	: T_VARIABLE
 					{
 						if (yylval.var->datatype->typoid != REFCURSOROID)
 						{
-							plpgsql_comperrinfo();
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "%s must be of type refcursor", yylval.var->refname);
 						}
 						$$ = yylval.var->varno;
@@ -1545,7 +1545,6 @@ read_sqlstmt (int until, char *s, char *sqlstart)
 		{
 			case 0:
 				plpgsql_error_lineno = lno;
-				plpgsql_comperrinfo();
 				elog(ERROR, "missing %s at end of SQL statement", s);
 				break;
 
@@ -1613,7 +1612,6 @@ read_datatype(int tok)
 		if (tok == 0)
 		{
 			plpgsql_error_lineno = lno;
-			plpgsql_comperrinfo();
 			elog(ERROR, "incomplete datatype declaration");
 		}
 		/* Possible followers for datatype in a declaration */
@@ -1636,6 +1634,8 @@ read_datatype(int tok)
 
 	plpgsql_push_back_token(tok);
 
+	plpgsql_error_lineno = lno;	/* in case of error in parse_datatype */
+
 	result = plpgsql_parse_datatype(plpgsql_dstring_get(&ds));
 
 	plpgsql_dstring_free(&ds);
@@ -1711,7 +1711,6 @@ make_select_stmt()
 				if (tok == 0)
 				{
 					plpgsql_error_lineno = yylineno;
-					plpgsql_comperrinfo();
 					elog(ERROR, "unexpected end of file");
 				}
 				plpgsql_dstring_append(&ds, yytext);
@@ -1772,6 +1771,7 @@ make_select_stmt()
 							break;
 
 						default:
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "plpgsql: %s is not a variable or record field", yytext);
 					}
 				}
@@ -1850,7 +1850,6 @@ make_select_stmt()
 							if (tok == 0)
 							{
 								plpgsql_error_lineno = yylineno;
-								plpgsql_comperrinfo();
 								elog(ERROR, "unexpected end of file");
 							}
 							plpgsql_dstring_append(&ds, yytext);
@@ -1899,7 +1898,6 @@ make_select_stmt()
 				if (tok == 0)
 				{
 					plpgsql_error_lineno = yylineno;
-					plpgsql_comperrinfo();
 					elog(ERROR, "unexpected end of file");
 				}
 				plpgsql_dstring_append(&ds, yytext);
@@ -1989,6 +1987,7 @@ make_fetch_stmt()
 							break;
 
 						default:
+							plpgsql_error_lineno = yylineno;
 							elog(ERROR, "plpgsql: %s is not a variable or record field", yytext);
 					}
 				}
@@ -2013,16 +2012,18 @@ make_fetch_stmt()
 			break;
 
 		default:
-			{
-				elog(ERROR, "syntax error at '%s'", yytext);
-			}
+			plpgsql_error_lineno = yylineno;
+			elog(ERROR, "syntax error at '%s'", yytext);
 	}
 
 	if (!have_nexttok)
 		tok = yylex();
 
 	if (tok != ';')
+	{
+		plpgsql_error_lineno = yylineno;
 		elog(ERROR, "syntax error at '%s'", yytext);
+	}
 
 	fetch = malloc(sizeof(PLpgSQL_stmt_select));
 	memset(fetch, 0, sizeof(PLpgSQL_stmt_fetch));
diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
index c06a2c8781..39630876ef 100644
--- a/src/pl/plpgsql/src/pl_comp.c
+++ b/src/pl/plpgsql/src/pl_comp.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.35 2001/10/09 04:15:38 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.36 2001/10/09 15:59:56 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -40,6 +40,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <ctype.h>
+#include <setjmp.h>
 
 #include "pl.tab.h"
 
@@ -55,6 +56,7 @@
 #include "fmgr.h"
 #include "parser/gramparse.h"
 #include "parser/parse_type.h"
+#include "tcop/tcopprot.h"
 #include "utils/builtins.h"
 #include "utils/syscache.h"
 
@@ -119,18 +121,7 @@ plpgsql_compile(Oid fn_oid, int functype)
 	PLpgSQL_rec *rec;
 	int			i;
 	int			arg_varnos[FUNC_MAX_ARGS];
-
-	/*
-	 * Initialize the compiler
-	 */
-	plpgsql_ns_init();
-	plpgsql_ns_push(NULL);
-	plpgsql_DumpExecTree = 0;
-
-	datums_alloc = 128;
-	plpgsql_nDatums = 0;
-	plpgsql_Datums = palloc(sizeof(PLpgSQL_datum *) * datums_alloc);
-	datums_last = 0;
+	sigjmp_buf	save_restart;
 
 	/*
 	 * Lookup the pg_proc tuple by Oid
@@ -152,15 +143,52 @@ plpgsql_compile(Oid fn_oid, int functype)
 	plpgsql_error_lineno = 0;
 
 	/*
+	 * Catch elog() so we can provide notice about where the error is
+	 */
+	memcpy(&save_restart, &Warn_restart, sizeof(save_restart));
+	if (sigsetjmp(Warn_restart, 1) != 0)
+	{
+		memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
+
+		/*
+		 * If we are the first of cascaded error catchings, print where
+		 * this happened
+		 */
+		if (plpgsql_error_funcname != NULL)
+		{
+			elog(NOTICE, "plpgsql: ERROR during compile of %s near line %d",
+				 plpgsql_error_funcname, plpgsql_error_lineno);
+
+			plpgsql_error_funcname = NULL;
+		}
+
+		siglongjmp(Warn_restart, 1);
+	}
+
+	/*
+	 * Initialize the compiler
+	 */
+	plpgsql_ns_init();
+	plpgsql_ns_push(NULL);
+	plpgsql_DumpExecTree = 0;
+
+	datums_alloc = 128;
+	plpgsql_nDatums = 0;
+	plpgsql_Datums = palloc(sizeof(PLpgSQL_datum *) * datums_alloc);
+	datums_last = 0;
+
+	/*
 	 * Create the new function node
 	 */
 	function = malloc(sizeof(PLpgSQL_function));
 	memset(function, 0, sizeof(PLpgSQL_function));
 	plpgsql_curr_compile = function;
 
-	function->fn_functype = functype;
-	function->fn_oid = fn_oid;
 	function->fn_name = strdup(NameStr(procStruct->proname));
+	function->fn_oid = fn_oid;
+	function->fn_xmin = procTup->t_data->t_xmin;
+	function->fn_cmin = procTup->t_data->t_cmin;
+	function->fn_functype = functype;
 
 	switch (functype)
 	{
@@ -180,7 +208,6 @@ plpgsql_compile(Oid fn_oid, int functype)
 									 0, 0, 0);
 			if (!HeapTupleIsValid(typeTup))
 			{
-				plpgsql_comperrinfo();
 				if (!OidIsValid(procStruct->prorettype))
 					elog(ERROR, "plpgsql functions cannot return type \"opaque\""
 						 "\n\texcept when used as triggers");
@@ -215,7 +242,6 @@ plpgsql_compile(Oid fn_oid, int functype)
 										 0, 0, 0);
 				if (!HeapTupleIsValid(typeTup))
 				{
-					plpgsql_comperrinfo();
 					if (!OidIsValid(procStruct->proargtypes[i]))
 						elog(ERROR, "plpgsql functions cannot take type \"opaque\"");
 					else
@@ -233,11 +259,8 @@ plpgsql_compile(Oid fn_oid, int functype)
 					 */
 					sprintf(buf, "%s%%rowtype", NameStr(typeStruct->typname));
 					if (plpgsql_parse_wordrowtype(buf) != T_ROW)
-					{
-						plpgsql_comperrinfo();
 						elog(ERROR, "cannot get tuple struct of argument %d",
 							 i + 1);
-					}
 
 					row = plpgsql_yylval.row;
 					sprintf(buf, "$%d", i + 1);
@@ -485,10 +508,7 @@ plpgsql_compile(Oid fn_oid, int functype)
 	 */
 	parse_rc = plpgsql_yyparse();
 	if (parse_rc != 0)
-	{
-		plpgsql_comperrinfo();
 		elog(ERROR, "plpgsql: parser returned %d ???", parse_rc);
-	}
 
 	/*
 	 * If that was successful, complete the functions info.
@@ -505,6 +525,13 @@ plpgsql_compile(Oid fn_oid, int functype)
 	ReleaseSysCache(procTup);
 
 	/*
+	 * Restore the previous elog() jump target
+	 */
+	plpgsql_error_funcname = NULL;
+	plpgsql_error_lineno = 0;
+	memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
+
+	/*
 	 * Finally return the compiled function
 	 */
 	if (plpgsql_DumpExecTree)
@@ -703,7 +730,6 @@ plpgsql_parse_dblword(char *string)
 						return T_VARIABLE;
 					}
 				}
-				plpgsql_comperrinfo();
 				elog(ERROR, "row %s doesn't have a field %s",
 					 word1, word2);
 			}
@@ -807,7 +833,6 @@ plpgsql_parse_tripword(char *string)
 						return T_VARIABLE;
 					}
 				}
-				plpgsql_comperrinfo();
 				elog(ERROR, "row %s.%s doesn't have a field %s",
 					 word1, word2, word3);
 			}
@@ -989,10 +1014,12 @@ plpgsql_parse_dblwordtype(char *string)
 	}
 
 	/*
-	 * It must be a (shared) relation class
+	 * It must be a relation, sequence or view
 	 */
 	classStruct = (Form_pg_class) GETSTRUCT(classtup);
-	if (classStruct->relkind != 'r' && classStruct->relkind != 's')
+	if (classStruct->relkind != RELKIND_RELATION &&
+		classStruct->relkind != RELKIND_SEQUENCE &&
+		classStruct->relkind != RELKIND_VIEW)
 	{
 		ReleaseSysCache(classtup);
 		pfree(word1);
@@ -1018,11 +1045,8 @@ plpgsql_parse_dblwordtype(char *string)
 							 ObjectIdGetDatum(attrStruct->atttypid),
 							 0, 0, 0);
 	if (!HeapTupleIsValid(typetup))
-	{
-		plpgsql_comperrinfo();
 		elog(ERROR, "cache lookup for type %u of %s.%s failed",
 			 attrStruct->atttypid, word1, word2);
-	}
 	typeStruct = (Form_pg_type) GETSTRUCT(typetup);
 
 	/*
@@ -1079,19 +1103,13 @@ plpgsql_parse_wordrowtype(char *string)
 							  PointerGetDatum(word1),
 							  0, 0, 0);
 	if (!HeapTupleIsValid(classtup))
-	{
-		plpgsql_comperrinfo();
 		elog(ERROR, "%s: no such class", word1);
-	}
 	classStruct = (Form_pg_class) GETSTRUCT(classtup);
 	/* accept relation, sequence, or view pg_class entries */
-	if (classStruct->relkind != 'r' &&
-		classStruct->relkind != 's' &&
-		classStruct->relkind != 'v')
-	{
-		plpgsql_comperrinfo();
+	if (classStruct->relkind != RELKIND_RELATION &&
+		classStruct->relkind != RELKIND_SEQUENCE &&
+		classStruct->relkind != RELKIND_VIEW)
 		elog(ERROR, "%s isn't a table", word1);
-	}
 
 	/*
 	 * Fetch the table's pg_type tuple too
@@ -1100,10 +1118,7 @@ plpgsql_parse_wordrowtype(char *string)
 							 PointerGetDatum(word1),
 							 0, 0, 0);
 	if (!HeapTupleIsValid(typetup))
-	{
-		plpgsql_comperrinfo();
 		elog(ERROR, "cache lookup for %s in pg_type failed", word1);
-	}
 
 	/*
 	 * Create a row datum entry and all the required variables that it
@@ -1131,11 +1146,8 @@ plpgsql_parse_wordrowtype(char *string)
 								 Int16GetDatum(i + 1),
 								 0, 0);
 		if (!HeapTupleIsValid(attrtup))
-		{
-			plpgsql_comperrinfo();
 			elog(ERROR, "cache lookup for attribute %d of class %s failed",
 				 i + 1, word1);
-		}
 		attrStruct = (Form_pg_attribute) GETSTRUCT(attrtup);
 
 		cp = pstrdup(NameStr(attrStruct->attname));
@@ -1144,11 +1156,8 @@ plpgsql_parse_wordrowtype(char *string)
 								 ObjectIdGetDatum(attrStruct->atttypid),
 								 0, 0, 0);
 		if (!HeapTupleIsValid(typetup))
-		{
-			plpgsql_comperrinfo();
 			elog(ERROR, "cache lookup for type %u of %s.%s failed",
 				 attrStruct->atttypid, word1, cp);
-		}
 		typeStruct = (Form_pg_type) GETSTRUCT(typetup);
 
 		/*
@@ -1316,19 +1325,6 @@ plpgsql_add_initdatums(int **varnos)
 }
 
 
-/* ----------
- * plpgsql_comperrinfo			Called before elog(ERROR, ...)
- *					during compile.
- * ----------
- */
-void
-plpgsql_comperrinfo()
-{
-	elog(NOTICE, "plpgsql: ERROR during compile of %s near line %d",
-		 plpgsql_error_funcname, plpgsql_error_lineno);
-}
-
-
 /* ---------
  * plpgsql_yyerror			Handle parser error
  * ---------
@@ -1338,6 +1334,5 @@ void
 plpgsql_yyerror(const char *s)
 {
 	plpgsql_error_lineno = plpgsql_yylineno;
-	plpgsql_comperrinfo();
 	elog(ERROR, "%s at or near \"%s\"", s, plpgsql_yytext);
 }
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index cce131b0c2..61ab93a6cd 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.15 2001/07/12 17:42:08 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.16 2001/10/09 15:59:56 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -324,6 +324,7 @@ plpgsql_ns_rename(char *oldname, char *newname)
 char *
 plpgsql_tolower(char *s)
 {
+	char	   *sstart = s;
 	char	   *ret;
 	char	   *cp;
 
@@ -342,10 +343,7 @@ plpgsql_tolower(char *s)
 				*cp++ = *s++;
 			}
 			if (*s != '"')
-			{
-				plpgsql_comperrinfo();
-				elog(ERROR, "unterminated \"");
-			}
+				elog(ERROR, "unterminated \" in name %s", sstart);
 			s++;
 		}
 		else
diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 8801ce55e3..bacd287fdd 100644
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_handler.c,v 1.8 2001/03/22 06:16:21 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_handler.c,v 1.9 2001/10/09 15:59:56 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -58,6 +58,9 @@
 static PLpgSQL_function *compiled_functions = NULL;
 
 
+static bool func_up_to_date(PLpgSQL_function *func);
+
+
 /* ----------
  * plpgsql_call_handler
  *
@@ -72,6 +75,7 @@ Datum
 plpgsql_call_handler(PG_FUNCTION_ARGS)
 {
 	bool		isTrigger = CALLED_AS_TRIGGER(fcinfo);
+	Oid			funcOid = fcinfo->flinfo->fn_oid;
 	PLpgSQL_function *func;
 	Datum		retval;
 
@@ -86,17 +90,24 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 	 * (ie, current FmgrInfo has been used before)
 	 */
 	func = (PLpgSQL_function *) fcinfo->flinfo->fn_extra;
-	if (func == NULL)
+	if (func != NULL)
 	{
-
+		Assert(func->fn_oid == funcOid);
 		/*
-		 * Check if we already compiled this function
+		 * But is the function still up to date?
 		 */
-		Oid			funcOid = fcinfo->flinfo->fn_oid;
+		if (! func_up_to_date(func))
+			func = NULL;
+	}
 
+	if (func == NULL)
+	{
+		/*
+		 * Check if we already compiled this function for another caller
+		 */
 		for (func = compiled_functions; func != NULL; func = func->next)
 		{
-			if (funcOid == func->fn_oid)
+			if (funcOid == func->fn_oid && func_up_to_date(func))
 				break;
 		}
 
@@ -135,3 +146,30 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
 
 	return retval;
 }
+
+
+/*
+ * Check to see if a compiled function is still up-to-date.  This
+ * is needed because CREATE OR REPLACE FUNCTION can modify the
+ * function's pg_proc entry without changing its OID.
+ */
+static bool
+func_up_to_date(PLpgSQL_function *func)
+{
+	HeapTuple	procTup;
+	bool		result;
+
+	procTup = SearchSysCache(PROCOID,
+							 ObjectIdGetDatum(func->fn_oid),
+							 0, 0, 0);
+	if (!HeapTupleIsValid(procTup))
+		elog(ERROR, "plpgsql: cache lookup for proc %u failed",
+			 func->fn_oid);
+
+	result = (func->fn_xmin == procTup->t_data->t_xmin &&
+			  func->fn_cmin == procTup->t_data->t_cmin);
+
+	ReleaseSysCache(procTup);
+
+	return result;
+}
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index fc2032dbd6..147659e7cc 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.18 2001/10/09 04:15:38 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.19 2001/10/09 15:59:56 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -455,9 +455,12 @@ typedef struct
 
 typedef struct PLpgSQL_function
 {								/* Complete compiled function	  */
-	Oid			fn_oid;
 	char	   *fn_name;
+	Oid			fn_oid;
+	TransactionId fn_xmin;
+	CommandId	fn_cmin;
 	int			fn_functype;
+
 	Oid			fn_rettype;
 	int			fn_rettyplen;
 	bool		fn_retbyval;
@@ -482,7 +485,8 @@ typedef struct PLpgSQL_function
 	int			ndatums;
 	PLpgSQL_datum **datums;
 	PLpgSQL_stmt_block *action;
-	struct PLpgSQL_function *next;
+
+	struct PLpgSQL_function *next; /* for chaining list of functions */
 }			PLpgSQL_function;
 
 
@@ -549,7 +553,6 @@ extern int	plpgsql_parse_wordrowtype(char *string);
 extern PLpgSQL_type *plpgsql_parse_datatype(char *string);
 extern void plpgsql_adddatum(PLpgSQL_datum * new);
 extern int	plpgsql_add_initdatums(int **varnos);
-extern void plpgsql_comperrinfo(void);
 extern void plpgsql_yyerror(const char *s);
 
 /* ----------
diff --git a/src/pl/plpgsql/src/scan.l b/src/pl/plpgsql/src/scan.l
index dfb16f8177..49191fa106 100644
--- a/src/pl/plpgsql/src/scan.l
+++ b/src/pl/plpgsql/src/scan.l
@@ -4,7 +4,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/pl/plpgsql/src/Attic/scan.l,v 1.15 2001/10/09 04:15:38 tgl Exp $
+ *    $Header: /cvsroot/pgsql/src/pl/plpgsql/src/Attic/scan.l,v 1.16 2001/10/09 15:59:56 tgl Exp $
  *
  *    This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -180,9 +180,9 @@ dump			{ return O_DUMP;			}
 <IN_COMMENT>\*\/	{ BEGIN INITIAL;			}
 <IN_COMMENT>\n		;
 <IN_COMMENT>.		;
-<IN_COMMENT><<EOF>>	{ plpgsql_comperrinfo();
-			  elog(ERROR, "unterminated comment starting on line %d",
-				start_lineno);
+<IN_COMMENT><<EOF>>	{
+				plpgsql_error_lineno = start_lineno;
+				elog(ERROR, "unterminated comment");
 			}
 
     /* ----------
@@ -198,9 +198,9 @@ dump			{ return O_DUMP;			}
 <IN_STRING>'		{ BEGIN INITIAL;
 			  return T_STRING;
 			}
-<IN_STRING><<EOF>>	{ plpgsql_comperrinfo();
-			  elog(ERROR, "unterminated string starting on line %d", 
-				start_lineno);
+<IN_STRING><<EOF>>	{
+				plpgsql_error_lineno = start_lineno;
+				elog(ERROR, "unterminated string");
 			}
 <IN_STRING>[^'\\]*	{ yymore();				}