c: SYM expr should store decl ref as an index, not pointer

Because envdecls (now declsbuf) can be resized and invalidate those
pointers. I missed this because the default initialization size of that
buffer (and the fact that it would mostly only manifest with
function-local expressions) made it not really come up in practice.
Silly

1 files changed, 4 insertions, 2 deletions

diff --git a/c/c.h b/c/c.h
index a31a1fd..da30616 100644
--- a/c/c.h
+++ b/c/c.h
@@ -45,7 +45,8 @@ struct expr {
         };
         uint n;
      } s; /* ESTRLIT */
-     struct decl *sym; /* ESYM */
+     int decl; /* ESYM, index into declsbuf */
+     internstr implicitsym; /* ESYM (undeclared) */
      struct init *init; /* EINIT */
    };
 };
@@ -101,9 +102,10 @@ struct decl {
    };
 };
 
+extern struct envdecls {vec_of(struct decl);} declsbuf;
 extern union type cvalistty;
 struct function;
-struct decl *envadddecl(struct env *env, const struct decl *d);
+int envadddecl(struct env *env, const struct decl *d);
 bool assigncheck(union type t, const struct expr *src);
 union ref expraddr(struct function *, const struct expr *);
 union ref compileexpr(struct function *, const struct expr *, bool discard);