Remove `patch_irep()` in `mruby-eval`

- It can now deal with operands in the range of `OP_EXT*`.
- It can now call the same method as the variable name without arguments.

  ```ruby
  def a
    "Safe!"
  end

  a = "Auto!"

  eval "a()" # call method `a`
  ```

1 files changed, 2 insertions, 213 deletions

diff --git a/mrbgems/mruby-eval/src/eval.c b/mrbgems/mruby-eval/src/eval.c
index ca046d88e..73e23392b 100644
--- a/mrbgems/mruby-eval/src/eval.c
+++ b/mrbgems/mruby-eval/src/eval.c
@@ -9,217 +9,6 @@
 mrb_value mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p);
 mrb_value mrb_obj_instance_eval(mrb_state *mrb, mrb_value self);
 
-static struct mrb_irep *
-get_closure_irep(mrb_state *mrb, int level)
-{
-  struct RProc *proc = mrb->c->ci[-1].proc;
-
-  while (level--) {
-    if (!proc) return NULL;
-    proc = proc->upper;
-  }
-  if (!proc) return NULL;
-  if (MRB_PROC_CFUNC_P(proc)) {
-    return NULL;
-  }
-  return proc->body.irep;
-}
-
-/* search for irep lev above the bottom */
-static mrb_irep*
-search_irep(mrb_irep *top, int bnest, int lev, mrb_irep *bottom)
-{
-  int i;
-
-  for (i=0; i<top->rlen; i++) {
-    mrb_irep* tmp = top->reps[i];
-
-    if (tmp == bottom) return top;
-    tmp = search_irep(tmp, bnest-1, lev, bottom);
-    if (tmp) {
-      if (bnest == lev) return top;
-      return tmp;
-    }
-  }
-  return NULL;
-}
-
-static uint16_t
-search_variable(mrb_state *mrb, mrb_sym vsym, int bnest)
-{
-  mrb_irep *virep;
-  int level;
-  int pos;
-
-  for (level = 0; (virep = get_closure_irep(mrb, level)); level++) {
-    if (virep->lv == NULL) {
-      continue;
-    }
-    for (pos = 0; pos < virep->nlocals - 1; pos++) {
-      if (vsym == virep->lv[pos].name) {
-        return (pos+1)<<8 | (level+bnest);
-      }
-    }
-  }
-
-  return 0;
-}
-
-static int
-irep_argc(mrb_irep *irep)
-{
-  mrb_code c;
-
-  c = irep->iseq[0];
-  if (c == OP_ENTER) {
-    mrb_aspec ax = PEEK_W(irep->iseq+1);
-    /* extra 1 means a slot for block */
-    return MRB_ASPEC_REQ(ax)+MRB_ASPEC_OPT(ax)+MRB_ASPEC_REST(ax)+MRB_ASPEC_POST(ax)+1;
-  }
-  return 0;
-}
-
-static mrb_bool
-potential_upvar_p(struct mrb_locals *lv, uint16_t v, int argc, uint16_t nlocals)
-{
-  if (v >= nlocals) return FALSE;
-  /* skip arguments  */
-  if (v < argc+1) return FALSE;
-  return TRUE;
-}
-
-extern uint8_t mrb_insn_size[];
-extern uint8_t mrb_insn_size1[];
-extern uint8_t mrb_insn_size2[];
-extern uint8_t mrb_insn_size3[];
-
-static void
-patch_irep(mrb_state *mrb, mrb_irep *irep, int bnest, mrb_irep *top)
-{
-  int i;
-  uint32_t a;
-  uint16_t b;
-  uint8_t c;
-  mrb_code insn;
-  int argc = irep_argc(irep);
-  mrb_code *iseq = (mrb_code *)irep->iseq;
-
-  mrb_assert((irep->flags & MRB_ISEQ_NO_FREE) == 0);
-
-  for (i = 0; i < irep->ilen; ) {
-    insn = iseq[i];
-    switch(insn){
-    case OP_EPUSH:
-      a = PEEK_B(iseq+i+1);
-      patch_irep(mrb, irep->reps[a], bnest + 1, top);
-      break;
-
-    case OP_LAMBDA:
-    case OP_BLOCK:
-      a = PEEK_B(iseq+i+1);
-      b = PEEK_B(iseq+i+2);
-      patch_irep(mrb, irep->reps[b], bnest + 1, top);
-      break;
-
-    case OP_SEND:
-      b = PEEK_B(iseq+i+2);
-      c = PEEK_B(iseq+i+3);
-      if (c != 0) {
-        break;
-      }
-      else {
-        uint16_t arg = search_variable(mrb, irep->syms[b], bnest);
-        if (arg != 0) {
-          /* must replace */
-          iseq[i] = OP_GETUPVAR;
-          iseq[i+2] = arg >> 8;
-          iseq[i+3] = arg & 0xff;
-        }
-      }
-      break;
-
-    case OP_MOVE:
-      a = PEEK_B(iseq+i+1);
-      b = PEEK_B(iseq+i+2);
-      /* src part */
-      if (potential_upvar_p(irep->lv, b, argc, irep->nlocals)) {
-        uint16_t arg = search_variable(mrb, irep->lv[b - 1].name, bnest);
-        if (arg != 0) {
-          /* must replace */
-          iseq[i] = insn = OP_GETUPVAR;
-          iseq[i+2] = arg >> 8;
-          iseq[i+3] = arg & 0xff;
-        }
-      }
-      /* dst part */
-      if (potential_upvar_p(irep->lv, a, argc, irep->nlocals)) {
-        uint16_t arg = search_variable(mrb, irep->lv[a - 1].name, bnest);
-        if (arg != 0) {
-          /* must replace */
-          iseq[i] = insn = OP_SETUPVAR;
-          iseq[i+1] = (mrb_code)b;
-          iseq[i+2] = arg >> 8;
-          iseq[i+3] = arg & 0xff;
-        }
-      }
-      break;
-
-    case OP_GETUPVAR:
-      a = PEEK_B(iseq+i+1);
-      b = PEEK_B(iseq+i+2);
-      c = PEEK_B(iseq+i+3);
-      {
-        int lev = c+1;
-        mrb_irep *tmp = search_irep(top, bnest, lev, irep);
-        if (potential_upvar_p(tmp->lv, b, irep_argc(tmp), tmp->nlocals)) {
-          uint16_t arg = search_variable(mrb, tmp->lv[b-1].name, bnest);
-          if (arg != 0) {
-            /* must replace */
-            iseq[i] = OP_GETUPVAR;
-            iseq[i+2] = arg >> 8;
-            iseq[i+3] = arg & 0xff;
-          }
-        }
-      }
-      break;
-
-    case OP_SETUPVAR:
-      a = PEEK_B(iseq+i+1);
-      b = PEEK_B(iseq+i+2);
-      c = PEEK_B(iseq+i+3);
-      {
-        int lev = c+1;
-        mrb_irep *tmp = search_irep(top, bnest, lev, irep);
-        if (potential_upvar_p(tmp->lv, b, irep_argc(tmp), tmp->nlocals)) {
-          uint16_t arg = search_variable(mrb, tmp->lv[b-1].name, bnest);
-          if (arg != 0) {
-            /* must replace */
-            iseq[i] = OP_SETUPVAR;
-            iseq[i+1] = a;
-            iseq[i+2] = arg >> 8;
-            iseq[i+3] = arg & 0xff;
-          }
-        }
-      }
-      break;
-
-    case OP_EXT1:
-      insn = PEEK_B(iseq+i+1);
-      i += mrb_insn_size1[insn]+1;
-      continue;
-    case OP_EXT2:
-      insn = PEEK_B(iseq+i+1);
-      i += mrb_insn_size2[insn]+1;
-      continue;
-    case OP_EXT3:
-      insn = PEEK_B(iseq+i+1);
-      i += mrb_insn_size3[insn]+1;
-      continue;
-    }
-    i+=mrb_insn_size[insn];
-  }
-}
-
 void mrb_codedump_all(mrb_state*, struct RProc*);
 
 static struct RProc*
@@ -243,7 +32,8 @@ create_proc_from_string(mrb_state *mrb, char *s, mrb_int len, mrb_value binding,
   mrbc_filename(mrb, cxt, file ? file : "(eval)");
   cxt->capture_errors = TRUE;
   cxt->no_optimize = TRUE;
-  cxt->on_eval = TRUE;
+  ci = (mrb->c->ci > mrb->c->cibase) ? mrb->c->ci - 1 : mrb->c->cibase;
+  cxt->upper = ci->proc && MRB_PROC_CFUNC_P(ci->proc) ? NULL : ci->proc;
 
   p = mrb_parse_nstring(mrb, s, len, cxt);
 
@@ -311,7 +101,6 @@ create_proc_from_string(mrb_state *mrb, char *s, mrb_int len, mrb_value binding,
   }
   proc->upper = ci->proc;
   mrb->c->ci->target_class = target_class;
-  patch_irep(mrb, proc->body.irep, 0, proc->body.irep);
   /* mrb_codedump_all(mrb, proc); */
 
   mrb_parser_free(p);