Since plpgsql keeps its compiled function parsetrees until backend exit,

it needs to ensure that data structures attached to fmgr info records in
the trees will stick around that long, too.  Current code was crashing
on cases like datatypes with old-style I/O functions.

Author: tglsfdc

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 1.28 2001/03/22 06:16:21 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.29 2001/04/06 02:06:48 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -85,6 +85,28 @@ int			plpgsql_DumpExecTree = 0;
 PLpgSQL_function *plpgsql_curr_compile;
 
 
+/*
+ * This routine is a crock, and so is everyplace that calls it.  The problem
+ * is that the compiled form of a plpgsql function is allocated permanently
+ * (mostly via malloc()) and never released until backend exit.  Subsidiary
+ * data structures such as fmgr info records therefore must live forever
+ * as well.  A better implementation would store all this stuff in a per-
+ * function memory context that could be reclaimed at need.  In the meantime,
+ * fmgr_info must be called in TopMemoryContext so that whatever it might
+ * allocate, and whatever the eventual function might allocate using fn_mcxt,
+ * will live forever too.
+ */
+static void
+perm_fmgr_info(Oid functionId, FmgrInfo *finfo)
+{
+	MemoryContext	oldcontext;
+
+	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+	fmgr_info(functionId, finfo);
+	MemoryContextSwitchTo(oldcontext);
+}
+
+
 /* ----------
  * plpgsql_compile		Given a pg_proc's oid, make
  *						an execution tree for it.
@@ -184,7 +206,7 @@ plpgsql_compile(Oid fn_oid, int functype)
 				function->fn_retbyval = typeStruct->typbyval;
 				function->fn_rettyplen = typeStruct->typlen;
 				function->fn_rettypelem = typeStruct->typelem;
-				fmgr_info(typeStruct->typinput, &(function->fn_retinput));
+				perm_fmgr_info(typeStruct->typinput, &(function->fn_retinput));
 			}
 			ReleaseSysCache(typeTup);
 
@@ -257,7 +279,7 @@ plpgsql_compile(Oid fn_oid, int functype)
 					var->datatype->typname = DatumGetCString(DirectFunctionCall1(nameout,
 								  NameGetDatum(&(typeStruct->typname))));
 					var->datatype->typoid = procStruct->proargtypes[i];
-					fmgr_info(typeStruct->typinput, &(var->datatype->typinput));
+					perm_fmgr_info(typeStruct->typinput, &(var->datatype->typinput));
 					var->datatype->typelem = typeStruct->typelem;
 					var->datatype->typbyval = typeStruct->typbyval;
 					var->datatype->atttypmod = -1;
@@ -607,7 +629,7 @@ plpgsql_parse_word(char *word)
 		typ->typname = DatumGetCString(DirectFunctionCall1(nameout,
 								  NameGetDatum(&(typeStruct->typname))));
 		typ->typoid = typeTup->t_data->t_oid;
-		fmgr_info(typeStruct->typinput, &(typ->typinput));
+		perm_fmgr_info(typeStruct->typinput, &(typ->typinput));
 		typ->typelem = typeStruct->typelem;
 		typ->typbyval = typeStruct->typbyval;
 		typ->atttypmod = -1;
@@ -923,7 +945,7 @@ plpgsql_parse_wordtype(char *word)
 		typ->typname = DatumGetCString(DirectFunctionCall1(nameout,
 								  NameGetDatum(&(typeStruct->typname))));
 		typ->typoid = typeTup->t_data->t_oid;
-		fmgr_info(typeStruct->typinput, &(typ->typinput));
+		perm_fmgr_info(typeStruct->typinput, &(typ->typinput));
 		typ->typelem = typeStruct->typelem;
 		typ->typbyval = typeStruct->typbyval;
 		typ->atttypmod = -1;
@@ -1066,7 +1088,7 @@ plpgsql_parse_dblwordtype(char *string)
 	typ->typname = DatumGetCString(DirectFunctionCall1(nameout,
 								  NameGetDatum(&(typeStruct->typname))));
 	typ->typoid = typetup->t_data->t_oid;
-	fmgr_info(typeStruct->typinput, &(typ->typinput));
+	perm_fmgr_info(typeStruct->typinput, &(typ->typinput));
 	typ->typelem = typeStruct->typelem;
 	typ->typbyval = typeStruct->typbyval;
 	typ->atttypmod = attrStruct->atttypmod;
@@ -1200,7 +1222,7 @@ plpgsql_parse_wordrowtype(char *string)
 		var->datatype = malloc(sizeof(PLpgSQL_type));
 		var->datatype->typname = strdup(NameStr(typeStruct->typname));
 		var->datatype->typoid = typetup->t_data->t_oid;
-		fmgr_info(typeStruct->typinput, &(var->datatype->typinput));
+		perm_fmgr_info(typeStruct->typinput, &(var->datatype->typinput));
 		var->datatype->typelem = typeStruct->typelem;
 		var->datatype->typbyval = typeStruct->typbyval;
 		var->datatype->atttypmod = attrStruct->atttypmod;