Prevent memory leaks in our various bison parsers when an error occurs

during parsing.  Formerly the parser's stack was allocated with malloc
and so wouldn't be reclaimed; this patch makes it use palloc instead,
so that flushing the current context will reclaim the memory.  Per
Marko Kreen.

1 files changed, 12 insertions, 1 deletions

diff --git a/src/backend/bootstrap/bootparse.y b/src/backend/bootstrap/bootparse.y
index 8019b244ae8..9997566002e 100644
--- a/src/backend/bootstrap/bootparse.y
+++ b/src/backend/bootstrap/bootparse.y
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/bootstrap/bootparse.y,v 1.93 2008/09/01 20:42:43 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/bootstrap/bootparse.y,v 1.94 2008/09/02 20:37:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -54,6 +54,17 @@
 #define atooid(x)	((Oid) strtoul((x), NULL, 10))
 
 
+/*
+ * Bison doesn't allocate anything that needs to live across parser calls,
+ * so we can easily have it use palloc instead of malloc.  This prevents
+ * memory leaks if we error out during parsing.  Note this only works with
+ * bison >= 2.0.  However, in bison 1.875 the default is to use alloca()
+ * if possible, so there's not really much problem anyhow, at least if
+ * you're building with gcc.
+ */
+#define YYMALLOC palloc
+#define YYFREE   pfree
+
 static void
 do_start(void)
 {