From 9d80b13932ac474de492b96fcffcf2a509d074af Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@factorcode.org>
Date: Mon, 22 Oct 2007 03:49:19 -0400
Subject: [PATCH] Add sanity check

---
 vm/code_heap.c | 5 +++++
 vm/debug.c     | 1 +
 2 files changed, 6 insertions(+)

diff --git a/vm/code_heap.c b/vm/code_heap.c
index fd910ef9d4..9487c7a47a 100644
--- a/vm/code_heap.c
+++ b/vm/code_heap.c
@@ -70,6 +70,11 @@ INLINE void reloc_set_2_2(CELL cell, CELL value)
 /* Store a value into a bitfield of a PowerPC instruction */
 INLINE void reloc_set_masked(CELL cell, F_FIXNUM value, CELL mask, F_FIXNUM shift)
 {
+	/* This is unaccurate but good enough */
+	F_FIXNUM test = (F_FIXNUM)mask >> 1;
+	if(value <= -test || value >= test)
+		critical_error("Value does not fit inside relocation",0);
+
 	u32 original = *(u32*)cell;
 	original &= ~mask;
 	*(u32*)cell = (original | ((value >> shift) & mask));
diff --git a/vm/debug.c b/vm/debug.c
index f0d74233d1..d8cfd1c599 100755
--- a/vm/debug.c
+++ b/vm/debug.c
@@ -111,6 +111,7 @@ void print_stack_frame(F_STACK_FRAME *frame)
 	printf("\n");
 	print_obj(frame_scan(frame));
 	printf("\n");
+	printf("%lx\n",(CELL)frame->xt);
 }
 
 void print_callstack(void)