Rearrange use of plpgsql_add_initdatums() so that only the parsing of a

tglsfdc · tglsfdc · commit 7ad33cebfdb7 · 2007-02-08T18:37:14.000Z
DECLARE section needs to know about it.  Formerly, everyplace besides DECLARE
that created variables needed to do "plpgsql_add_initdatums(NULL)" to prevent
those variables from being sucked up as part of a subsequent DECLARE block.
This is obviously error-prone, and in fact the SQLSTATE/SQLERRM patch had
failed to do it for those two variables, leading to the bug recently exhibited
by Asif Ali Rehman: a DECLARE within an exception handler tried to reinitialize
SQLERRM.

Although the SQLSTATE/SQLERRM patch isn't in any pre-8.1 branches, and so
I can't point to a demonstrable failure there, it seems wise to back-patch
this into the older branches anyway, just to keep the logic similar to HEAD.
diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.97 2007/02/01 19:10:29 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.98 2007/02/08 18:37:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -272,15 +272,13 @@ decl_sect		: opt_block_label
 						$$.label	  = $1;
 						$$.n_initvars = 0;
 						$$.initvarnos = NULL;
-						plpgsql_add_initdatums(NULL);
 					}
 				| opt_block_label decl_start
 					{
 						plpgsql_ns_setlocal(false);
 						$$.label	  = $1;
 						$$.n_initvars = 0;
 						$$.initvarnos = NULL;
-						plpgsql_add_initdatums(NULL);
 					}
 				| opt_block_label decl_start decl_stmts
 					{
@@ -289,12 +287,16 @@ decl_sect		: opt_block_label
 							$$.label = $3;
 						else
 							$$.label = $1;
+						/* Remember variables declared in decl_stmts */
 						$$.n_initvars = plpgsql_add_initdatums(&($$.initvarnos));
 					}
 				;
 
 decl_start		: K_DECLARE
 					{
+						/* Forget any variables created before block */
+						plpgsql_add_initdatums(NULL);
+						/* Make variable names be local to block */
 						plpgsql_ns_setlocal(true);
 					}
 				;
@@ -990,9 +992,6 @@ for_control		:
 																				  -1),
 														   true);
 
-								/* put the for-variable into the local block */
-								plpgsql_add_initdatums(NULL);
-
 								new = palloc0(sizeof(PLpgSQL_stmt_fori));
 								new->cmd_type = PLPGSQL_STMT_FORI;
 								new->lineno   = $1;
diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.111 2007/02/01 19:10:29 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.112 2007/02/08 18:37:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -666,11 +666,6 @@ do_compile(FunctionCallInfo fcinfo,
 								 true);
 	function->found_varno = var->dno;
 
-	/*
-	 * Forget about the above created variables
-	 */
-	plpgsql_add_initdatums(NULL);
-
 	/*
 	 * Now parse the function's text
 	 */
@@ -1893,11 +1888,17 @@ plpgsql_adddatum(PLpgSQL_datum *new)
 
 
 /* ----------
- * plpgsql_add_initdatums		Put all datum entries created
- *					since the last call into the
- *					finishing code block so the
- *					block knows which variables to
- *					reinitialize when entered.
+ * plpgsql_add_initdatums		Make an array of the datum numbers of
+ *					all the simple VAR datums created since the last call
+ *					to this function.
+ *
+ * If varnos is NULL, we just forget any datum entries created since the
+ * last call.
+ *
+ * This is used around a DECLARE section to create a list of the VARs
+ * that have to be initialized at block entry.  Note that VARs can also
+ * be created elsewhere than DECLARE, eg by a FOR-loop, but it is then
+ * the responsibility of special-purpose code to initialize them.
  * ----------
  */
 int

Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@`
`9`	`9`	`*`
`10`	`10`	`*`
`11`	`11`	`* IDENTIFICATION`
`12`		`- * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.97 2007/02/01 19:10:29 momjian Exp $`
	`12`	`+ * $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.98 2007/02/08 18:37:14 tgl Exp $`
`13`	`13`	`*`
`14`	`14`	`*-------------------------------------------------------------------------`
`15`	`15`	`*/`
`@@ -272,15 +272,13 @@ decl_sect : opt_block_label`
`272`	`272`	`$$.label = $1;`
`273`	`273`	`$$.n_initvars = 0;`
`274`	`274`	`$$.initvarnos = NULL;`
`275`		`- plpgsql_add_initdatums(NULL);`
`276`	`275`	`}`
`277`	`276`	`\| opt_block_label decl_start`
`278`	`277`	`{`
`279`	`278`	`plpgsql_ns_setlocal(false);`
`280`	`279`	`$$.label = $1;`
`281`	`280`	`$$.n_initvars = 0;`
`282`	`281`	`$$.initvarnos = NULL;`
`283`		`- plpgsql_add_initdatums(NULL);`
`284`	`282`	`}`
`285`	`283`	`\| opt_block_label decl_start decl_stmts`
`286`	`284`	`{`
`@@ -289,12 +287,16 @@ decl_sect : opt_block_label`
`289`	`287`	`$$.label = $3;`
`290`	`288`	`else`
`291`	`289`	`$$.label = $1;`
	`290`	`+ /* Remember variables declared in decl_stmts */`
`292`	`291`	`$$.n_initvars = plpgsql_add_initdatums(&($$.initvarnos));`
`293`	`292`	`}`
`294`	`293`	`;`
`295`	`294`
`296`	`295`	`decl_start : K_DECLARE`
`297`	`296`	`{`
	`297`	`+ /* Forget any variables created before block */`
	`298`	`+ plpgsql_add_initdatums(NULL);`
	`299`	`+ /* Make variable names be local to block */`
`298`	`300`	`plpgsql_ns_setlocal(true);`
`299`	`301`	`}`
`300`	`302`	`;`
`@@ -990,9 +992,6 @@ for_control :`
`990`	`992`	`-1),`
`991`	`993`	`true);`
`992`	`994`
`993`		`- /* put the for-variable into the local block */`
`994`		`- plpgsql_add_initdatums(NULL);`
`995`		`-`
`996`	`995`	`new = palloc0(sizeof(PLpgSQL_stmt_fori));`
`997`	`996`	`new->cmd_type = PLPGSQL_STMT_FORI;`
`998`	`997`	`new->lineno = $1;`