From patchwork Wed Apr 20 21:08:34 2011
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Subject: fix memory leak in gengtype
Date: Wed, 20 Apr 2011 11:08:34 -0000
From: Dimitrios Apostolou <jimis@gmx.net>
X-Patchwork-Id: 92324
Message-Id: <alpine.LNX.2.00.1104202353490.10280@localhost.localdomain>
To: gcc-patches@gcc.gnu.org

Hello list,

while trying to build gcc-4.6.0 on my sparcstation, I got gengtype OOM 
killed. That's when I noticed that its RAM usage peaks at 150MB, which is 
a bit excessive for parsing a ~500K text file.

The attached patch fixes the leak and gengtype now uses a peak of 4MB 
heap. Hopefully I don't do something wrong, since it took me a while to 
understand those obstacks...


Thanks,
Dimitris


P.S. I was trying to test gcc on a rare arch (sparc-unknown-linux-gnu) but 
unfortunately the sparcstation crashed and burned after this, so I can't 
continue the build and report back :-(


--- gcc/gengtype-state.c.orig	2011-04-20 23:06:29.000000000 +0300
+++ gcc/gengtype-state.c	2011-04-20 23:12:43.000000000 +0300
@@ -303,7 +303,7 @@
       obstack_1grow (&id_obstack, (char) 0);
       ids = XOBFINISH (&id_obstack, char *);
       sid = state_ident_by_name (ids, INSERT);
-      obstack_free (&id_obstack, ids);
+      obstack_free (&id_obstack, NULL);
       ids = NULL;
       tk = XCNEW (struct state_token_st);
       tk->stok_kind = STOK_NAME;
@@ -408,7 +408,7 @@
       tk->stok_file = state_path;
       tk->stok_next = NULL;
       strcpy (tk->stok_un.stok_string, cstr);
-      obstack_free (&bstring_obstack, cstr);
+      obstack_free (&bstring_obstack, NULL);
 
       return tk;
     }