vm: bugfix: global lexicals looked up dynamically.

The getlx and setlx VM instructions are using dynamic lookup
for uncached bindings, due to using the same lookup_fun
search function. They should use lookup_global_fun.
That doesn't have an environment parameter though, so the
type is not right. However, the VM never uses the environment
parameter; it's always passing nil. We will get rid of the
environment parameter in the lookup_fn callback and introduce
a few wrappers.

* eval.c, eval.h (lookup_global_fun, lookup_dynamic_var,
lookup_dynamic_sym_lisp1): New functions.

* vm.c (vm_stab_slowpath, vm_get_binding): lookup_fn argument
loses environment parameter, and so we don't have to pass nil.
(vm_gcall, vm_gapply): Use pass lookup_global_fun to
to vm_stab.
(vm_getsym, vm_getbind, vm_setsym, vm_gettab, vm_settab):
lookup_fn argument loses environment parameter.
(vm_execute): lookup functions replaced with the appropriate
one-argument ones. GETLX and SETLX see a behavior change,
due to using lookup_global_var which doesn't search the
dynamic environment.

1 files changed, 15 insertions, 0 deletions

diff --git a/eval.c b/eval.c
index 3c8d83f5..ab54586e 100644
--- a/eval.c
+++ b/eval.c
@@ -530,6 +530,11 @@ val lookup_global_var(val sym)
              if2(autoload_try_var(sym), gethash(top_vb, sym)));
 }
 
+val lookup_global_fun(val sym)
+{
+  return lookup_fun(nil, sym);
+}
+
 val lookup_var(val env, val sym)
 {
   if (env) {
@@ -593,6 +598,16 @@ loc lookup_var_l(val env, val sym)
   uw_throwf(error_s, lit("variable ~s unexpectedly unbound"), sym, nao);
 }
 
+val lookup_dynamic_var(val sym)
+{
+  return lookup_var(nil, sym);
+}
+
+val lookup_dynamic_sym_lisp1(val sym)
+{
+  return lookup_sym_lisp1(nil, sym);
+}
+
 static val lookup_mac(val menv, val sym);
 
 val lookup_fun(val env, val sym)