Validity-check the pseudo 'use' list.

This is largely how I found all the pseudo rewriting bugs, so
let's just make it the norm. I'm not a huge fan of asserts, but
as long as it's _really_ a "this is a fundamental problem" thing,
rather than a "I'm not handling this case correctly", they're ok.

1 files changed, 2 insertions, 0 deletions

diff --git a/flow.c b/flow.c
index f8e2a93..4643251 100644
--- a/flow.c
+++ b/flow.c
@@ -10,6 +10,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <stddef.h>
+#include <assert.h>
 
 #include "parse.h"
 #include "expression.h"
@@ -145,6 +146,7 @@ void convert_instruction_target(struct instruction *insn, pseudo_t src)
 	 */
 	target = insn->target;
 	FOR_EACH_PTR(target->users, usep) {
+		assert(*usep == target);
 		*usep = src;
 	} END_FOR_EACH_PTR(usep);
 	concat_user_list(target->users, &src->users);