Make `mrb_exec_irep()` allow non-VM to enter.

Change the old `mrb_exec_irep()` as-is to static `mrb_exec_irep_vm()`.
Extract the VM entry part from the old `exec_irep()` in `mruby-eval/src/eval.c` and make it the core of the new `mrb_exec_irep()`.

2 files changed, 27 insertions, 13 deletions

diff --git a/mrbgems/mruby-eval/src/eval.c b/mrbgems/mruby-eval/src/eval.c
index 978d4fc30..508f5ffcb 100644
--- a/mrbgems/mruby-eval/src/eval.c
+++ b/mrbgems/mruby-eval/src/eval.c
@@ -131,15 +131,6 @@ exec_irep(mrb_state *mrb, mrb_value self, struct RProc *proc, mrb_func_t posthoo
 {
   /* no argument passed from eval() */
   mrb->c->ci->argc = 0;
-  if (mrb->c->ci->acc < 0) {
-    ptrdiff_t cioff = mrb->c->ci - mrb->c->cibase;
-    mrb_value ret = mrb_top_run(mrb, proc, self, 0);
-    if (mrb->exc) {
-      mrb_exc_raise(mrb, mrb_obj_value(mrb->exc));
-    }
-    mrb->c->ci = mrb->c->cibase + cioff;
-    return ret;
-  }
   /* clear block */
   mrb->c->ci->stack[1] = mrb_nil_value();
   return mrb_exec_irep(mrb, self, proc, posthook);
diff --git a/src/vm.c b/src/vm.c
index edfb55586..d7f2f58d7 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -543,8 +543,8 @@ mrb_exec_irep_prepare_posthook(mrb_state *mrb, mrb_callinfo *ci, int nregs, mrb_
  *
  * However, if `proc` is a C function, it will be ignored.
  */
-mrb_value
-mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook)
+static mrb_value
+mrb_exec_irep_vm(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook)
 {
   mrb_callinfo *ci = mrb->c->ci;
   int keep, nregs;
@@ -575,6 +575,29 @@ mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t postho
   return self;
 }
 
+mrb_value
+mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook)
+{
+  mrb_callinfo *ci = mrb->c->ci;
+  if (ci->acc >= 0) {
+    return mrb_exec_irep_vm(mrb, self, p, posthook);
+  }
+  else {
+    mrb_value ret;
+    if (MRB_PROC_CFUNC_P(p)) {
+      ret = MRB_PROC_CFUNC(p)(mrb, self);
+    }
+    else {
+      int keep = (ci->argc < 0 ? 1 : ci->argc) + 2 /* receiver + block */;
+      ret = mrb_top_run(mrb, p, self, keep);
+    }
+    if (mrb->exc && mrb->jmp) {
+      mrb_exc_raise(mrb, mrb_obj_value(mrb->exc));
+    }
+    return ret;
+  }
+}
+
 /* 15.3.1.3.4  */
 /* 15.3.1.3.44 */
 /*
@@ -638,7 +661,7 @@ mrb_f_send(mrb_state *mrb, mrb_value self)
     }
     return MRB_METHOD_CFUNC(m)(mrb, self);
   }
-  return mrb_exec_irep(mrb, self, MRB_METHOD_PROC(m), NULL);
+  return mrb_exec_irep_vm(mrb, self, MRB_METHOD_PROC(m), NULL);
 }
 
 static mrb_value
@@ -826,7 +849,7 @@ mrb_yield_cont(mrb_state *mrb, mrb_value b, mrb_value self, mrb_int argc, const
   mrb->c->ci->stack[1] = mrb_ary_new_from_values(mrb, argc, argv);
   mrb->c->ci->stack[2] = mrb_nil_value();
   ci->argc = -1;
-  return mrb_exec_irep(mrb, self, p, NULL);
+  return mrb_exec_irep_vm(mrb, self, p, NULL);
 }
 
 static struct RBreak*