Merge pull request #5493 from dearblue/binding.2

Fixed finding variables from `proc` in `binding.eval` failed

10 files changed, 247 insertions, 133 deletions

diff --git a/mrbgems/mruby-binding-core/src/binding-core.c b/mrbgems/mruby-binding-core/src/binding-core.c
index 57b1b5434..7b70cfb78 100644
--- a/mrbgems/mruby-binding-core/src/binding-core.c
+++ b/mrbgems/mruby-binding-core/src/binding-core.c
@@ -24,16 +24,16 @@ binding_extract_pc(mrb_state *mrb, mrb_value binding)
   }
 }
 
-static const struct RProc *
-binding_extract_proc(mrb_state *mrb, mrb_value binding)
+const struct RProc *
+mrb_binding_extract_proc(mrb_state *mrb, mrb_value binding)
 {
   mrb_value obj = mrb_iv_get(mrb, binding, MRB_SYM(proc));
   mrb_check_type(mrb, obj, MRB_TT_PROC);
   return mrb_proc_ptr(obj);
 }
 
-static struct REnv *
-binding_extract_env(mrb_state *mrb, mrb_value binding)
+struct REnv *
+mrb_binding_extract_env(mrb_state *mrb, mrb_value binding)
 {
   mrb_value obj = mrb_iv_get(mrb, binding, MRB_SYM(env));
   if (mrb_nil_p(obj)) {
@@ -108,8 +108,8 @@ binding_local_variable_defined_p(mrb_state *mrb, mrb_value self)
   mrb_sym varname;
   mrb_get_args(mrb, "n", &varname);
 
-  const struct RProc *proc = binding_extract_proc(mrb, self);
-  struct REnv *env = binding_extract_env(mrb, self);
+  const struct RProc *proc = mrb_binding_extract_proc(mrb, self);
+  struct REnv *env = mrb_binding_extract_env(mrb, self);
   mrb_value *e = binding_local_variable_search(mrb, proc, env, varname);
   if (e) {
     return mrb_true_value();
@@ -129,8 +129,8 @@ binding_local_variable_get(mrb_state *mrb, mrb_value self)
   mrb_sym varname;
   mrb_get_args(mrb, "n", &varname);
 
-  const struct RProc *proc = binding_extract_proc(mrb, self);
-  struct REnv *env = binding_extract_env(mrb, self);
+  const struct RProc *proc = mrb_binding_extract_proc(mrb, self);
+  struct REnv *env = mrb_binding_extract_env(mrb, self);
   mrb_value *e = binding_local_variable_search(mrb, proc, env, varname);
   if (!e) {
     mrb_raisef(mrb, E_NAME_ERROR, "local variable %!n is not defined", varname);
@@ -146,8 +146,8 @@ binding_local_variable_set(mrb_state *mrb, mrb_value self)
   mrb_value obj;
   mrb_get_args(mrb, "no", &varname, &obj);
 
-  const struct RProc *proc = binding_extract_proc(mrb, self);
-  struct REnv *env = binding_extract_env(mrb, self);
+  const struct RProc *proc = mrb_binding_extract_proc(mrb, self);
+  struct REnv *env = mrb_binding_extract_env(mrb, self);
   mrb_value *e = binding_local_variable_search(mrb, proc, env, varname);
   if (e) {
     *e = obj;
@@ -184,7 +184,7 @@ binding_source_location(mrb_state *mrb, mrb_value self)
   }
 
   mrb_value srcloc;
-  const struct RProc *proc = binding_extract_proc(mrb, self);
+  const struct RProc *proc = mrb_binding_extract_proc(mrb, self);
   if (!proc || MRB_PROC_CFUNC_P(proc) ||
       !proc->upper || MRB_PROC_CFUNC_P(proc->upper)) {
     srcloc = mrb_nil_value();
diff --git a/mrbgems/mruby-binding/mrblib/binding.rb b/mrbgems/mruby-binding/mrblib/binding.rb
deleted file mode 100644
index b07480db1..000000000
--- a/mrbgems/mruby-binding/mrblib/binding.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-class Binding
-  def eval(expr, *args)
-    Kernel.eval(expr, self, *args)
-  end
-end
diff --git a/mrbgems/mruby-binding/src/binding.c b/mrbgems/mruby-binding/src/binding.c
new file mode 100644
index 000000000..67692e2b9
--- /dev/null
+++ b/mrbgems/mruby-binding/src/binding.c
@@ -0,0 +1,173 @@
+#include <mruby.h>
+#include <mruby/array.h>
+#include <mruby/class.h>
+#include <mruby/compile.h>
+#include <mruby/error.h>
+#include <mruby/proc.h>
+#include <mruby/presym.h>
+#include <mruby/string.h>
+
+mrb_noreturn void mrb_method_missing(mrb_state *mrb, mrb_sym name, mrb_value self, mrb_value args);
+void mrb_proc_merge_lvar(mrb_state *mrb, mrb_irep *irep, struct REnv *env, int num, const mrb_sym *lv, const mrb_value *stack);
+mrb_value mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p);
+const struct RProc *mrb_binding_extract_proc(mrb_state *mrb, mrb_value binding);
+struct REnv *mrb_binding_extract_env(mrb_state *mrb, mrb_value binding);
+typedef mrb_bool mrb_parser_foreach_top_variable_func(mrb_state *mrb, mrb_sym sym, void *user);
+void mrb_parser_foreach_top_variable(mrb_state *mrb, struct mrb_parser_state *p, mrb_parser_foreach_top_variable_func *func, void *user);
+
+static void
+insert_args(mrb_state *mrb, size_t offset, mrb_value obj)
+{
+  mrb_callinfo *ci = mrb->c->ci;
+  mrb_value *argp = ci->stack + 1 /* recv */;
+
+  if (ci->argc < 0) {
+    mrb_ary_splice(mrb, *argp, offset, 0, obj);
+  }
+  else {
+    argp += offset;
+    mrb_stack_extend(mrb, ci->argc + offset + 2 /* recv + block */);
+    memmove(argp + 1 /* obj */, argp, sizeof(mrb_value) * (ci->argc - offset + 1 /* block */));
+    *argp = obj;
+    ci->argc++;
+  }
+}
+
+static void
+binding_eval_error_check(mrb_state *mrb, struct mrb_parser_state *p, const char *file)
+{
+  if (!p) {
+    mrb_raise(mrb, E_RUNTIME_ERROR, "Failed to create parser state (out of memory)");
+  }
+
+  if (0 < p->nerr) {
+    mrb_value str;
+
+    if (file) {
+      str = mrb_format(mrb, "file %s line %d: %s",
+                       file,
+                       p->error_buffer[0].lineno,
+                       p->error_buffer[0].message);
+    }
+    else {
+      str = mrb_format(mrb, "line %d: %s",
+                       p->error_buffer[0].lineno,
+                       p->error_buffer[0].message);
+    }
+    mrb_exc_raise(mrb, mrb_exc_new_str(mrb, E_SYNTAX_ERROR, str));
+  }
+}
+
+#define LV_BUFFERS 8
+
+struct expand_lvspace {
+  mrb_irep *irep;
+  struct REnv *env;
+  size_t numvar;
+  mrb_sym syms[LV_BUFFERS];
+};
+
+static mrb_bool
+expand_lvspace(mrb_state *mrb, mrb_sym sym, void *user)
+{
+  struct expand_lvspace *p = (struct expand_lvspace*)user;
+  mrb_int symlen;
+  const char *symname = mrb_sym_name_len(mrb, sym, &symlen);
+
+  if (symname && symlen > 0) {
+    if (symname[0] != '&' && symname[0] != '*') {
+      p->syms[p->numvar++] = sym;
+      if (p->numvar >= LV_BUFFERS) {
+        mrb_proc_merge_lvar(mrb, p->irep, p->env, p->numvar, p->syms, NULL);
+        p->numvar = 0;
+      }
+    }
+  }
+
+  return TRUE;
+}
+
+struct binding_eval_prepare_body {
+  mrb_value binding;
+  const char *file;
+  const char *expr;
+  mrb_int exprlen;
+  mrbc_context *mrbc;
+  struct mrb_parser_state *pstate;
+};
+
+static mrb_value
+binding_eval_prepare_body(mrb_state *mrb, void *opaque)
+{
+  struct binding_eval_prepare_body *p = (struct binding_eval_prepare_body*)opaque;
+
+  const struct RProc *proc = mrb_binding_extract_proc(mrb, p->binding);
+  mrb_assert(!MRB_PROC_CFUNC_P(proc));
+
+  p->mrbc = mrbc_context_new(mrb);
+  mrbc_filename(mrb, p->mrbc, p->file ? p->file : "(eval)");
+  p->mrbc->upper = proc;
+  p->mrbc->capture_errors = TRUE;
+  p->pstate = mrb_parse_nstring(mrb, p->expr, p->exprlen, p->mrbc);
+  binding_eval_error_check(mrb, p->pstate, p->file);
+
+  struct expand_lvspace args = {
+    (mrb_irep*)proc->body.irep,
+    mrb_binding_extract_env(mrb, p->binding),
+    0,
+    { 0 }
+  };
+  mrb_parser_foreach_top_variable(mrb, p->pstate, expand_lvspace, &args);
+  if (args.numvar > 0) {
+    mrb_proc_merge_lvar(mrb, args.irep, args.env, args.numvar, args.syms, NULL);
+  }
+
+  return mrb_nil_value();
+}
+
+static void
+binding_eval_prepare(mrb_state *mrb, mrb_value binding)
+{
+  struct binding_eval_prepare_body d = { binding, NULL, NULL, 0, NULL, NULL };
+  mrb_int argc;
+  mrb_value *argv;
+  mrb_get_args(mrb, "s|z*!", &d.expr, &d.exprlen, &d.file, &argv, &argc);
+
+  mrb_bool error;
+  mrb_value ret = mrb_protect_error(mrb, binding_eval_prepare_body, &d, &error);
+  if (d.pstate) mrb_parser_free(d.pstate);
+  if (d.mrbc) mrbc_context_free(mrb, d.mrbc);
+  if (error) mrb_exc_raise(mrb, ret);
+}
+
+static mrb_value
+mrb_binding_eval(mrb_state *mrb, mrb_value binding)
+{
+  binding_eval_prepare(mrb, binding);
+
+  struct RClass *c = mrb->kernel_module;
+  mrb_method_t m = mrb_method_search_vm(mrb, &c, MRB_SYM(eval));
+  if (MRB_METHOD_UNDEF_P(m)) {
+    int argc = mrb->c->ci->argc;
+    mrb_value *argv = mrb->c->ci->stack + 1;
+    mrb_value args = (argc < 0) ? argv[0] : mrb_ary_new_from_values(mrb, argc, argv);
+    mrb_method_missing(mrb, MRB_SYM(eval), binding, args);
+  }
+
+  insert_args(mrb, 1, binding);
+  struct RProc *proc = MRB_METHOD_PROC_P(m) ? MRB_METHOD_PROC(m) : mrb_proc_new_cfunc(mrb, MRB_METHOD_FUNC(m));
+  mrb->c->ci->u.target_class = c;
+  return mrb_exec_irep(mrb, binding, proc);
+}
+
+void
+mrb_mruby_binding_gem_init(mrb_state *mrb)
+{
+  struct RClass *binding = mrb_class_get_id(mrb, MRB_SYM(Binding));
+  mrb_define_method(mrb, binding, "eval", mrb_binding_eval, MRB_ARGS_ANY());
+}
+
+void
+mrb_mruby_binding_gem_final(mrb_state *mrb)
+{
+}
diff --git a/mrbgems/mruby-binding/test/binding.rb b/mrbgems/mruby-binding/test/binding.rb
index 7dd3fd1dd..296fb48d4 100644
--- a/mrbgems/mruby-binding/test/binding.rb
+++ b/mrbgems/mruby-binding/test/binding.rb
@@ -68,3 +68,10 @@ assert "Binding#eval with Binding.new via Method" do
 
   assert_true true
 end
+
+assert "access local variables into procs" do
+  bx = binding
+  block = bx.eval("a = 1; proc { a }")
+  bx.eval("a = 2")
+  assert_equal 2, block.call
+end
diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index 96615e3bb..7d9db4a2b 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -7759,3 +7759,19 @@ mrb_parser_dump(mrb_state *mrb, node *tree, int offset)
   }
 #endif
 }
+
+typedef mrb_bool mrb_parser_foreach_top_variable_func(mrb_state *mrb, mrb_sym sym, void *user);
+void mrb_parser_foreach_top_variable(mrb_state *mrb, struct mrb_parser_state *p, mrb_parser_foreach_top_variable_func *func, void *user);
+
+void
+mrb_parser_foreach_top_variable(mrb_state *mrb, struct mrb_parser_state *p, mrb_parser_foreach_top_variable_func *func, void *user)
+{
+  const mrb_ast_node *n = p->tree;
+  if ((intptr_t)n->car == NODE_SCOPE) {
+    n = n->cdr->car;
+    for (; n; n = n->cdr) {
+      mrb_sym sym = (intptr_t)n->car;
+      if (sym && !func(mrb, sym, user)) break;
+    }
+  }
+}
diff --git a/mrbgems/mruby-compiler/core/y.tab.c b/mrbgems/mruby-compiler/core/y.tab.c
index 3b2ce8043..9cd36ec7b 100644
--- a/mrbgems/mruby-compiler/core/y.tab.c
+++ b/mrbgems/mruby-compiler/core/y.tab.c
@@ -13951,3 +13951,19 @@ mrb_parser_dump(mrb_state *mrb, node *tree, int offset)
   }
 #endif
 }
+
+typedef mrb_bool mrb_parser_foreach_top_variable_func(mrb_state *mrb, mrb_sym sym, void *user);
+void mrb_parser_foreach_top_variable(mrb_state *mrb, struct mrb_parser_state *p, mrb_parser_foreach_top_variable_func *func, void *user);
+
+void
+mrb_parser_foreach_top_variable(mrb_state *mrb, struct mrb_parser_state *p, mrb_parser_foreach_top_variable_func *func, void *user)
+{
+  const mrb_ast_node *n = p->tree;
+  if ((intptr_t)n->car == NODE_SCOPE) {
+    n = n->cdr->car;
+    for (; n; n = n->cdr) {
+      mrb_sym sym = (intptr_t)n->car;
+      if (sym && !func(mrb, sym, user)) break;
+    }
+  }
+}
diff --git a/mrbgems/mruby-eval/src/eval.c b/mrbgems/mruby-eval/src/eval.c
index f1c5c475f..de1bcd02d 100644
--- a/mrbgems/mruby-eval/src/eval.c
+++ b/mrbgems/mruby-eval/src/eval.c
@@ -9,7 +9,7 @@
 #include <mruby/variable.h>
 
 struct REnv *mrb_env_new(mrb_state *mrb, struct mrb_context *c, mrb_callinfo *ci, int nstacks, mrb_value *stack, struct RClass *tc);
-mrb_value mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook);
+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);
 mrb_value mrb_mod_module_eval(mrb_state*, mrb_value);
 void mrb_codedump_all(mrb_state*, struct RProc*);
@@ -129,44 +129,13 @@ create_proc_from_string(mrb_state *mrb, const char *s, mrb_int len, mrb_value bi
 }
 
 static mrb_value
-exec_irep(mrb_state *mrb, mrb_value self, struct RProc *proc, mrb_func_t posthook)
+exec_irep(mrb_state *mrb, mrb_value self, struct RProc *proc)
 {
   /* no argument passed from eval() */
   mrb->c->ci->argc = 0;
   /* clear block */
   mrb->c->ci->stack[1] = mrb_nil_value();
-  return mrb_exec_irep(mrb, self, proc, posthook);
-}
-
-static void
-eval_merge_lvar(mrb_state *mrb, mrb_irep *irep, struct REnv *env, int num, const mrb_sym *lv, const mrb_value *stack)
-{
-  mrb_assert(mrb->c->stend >= stack + num);
-  mrb_proc_merge_lvar(mrb, irep, env, num, lv, stack);
-}
-
-static mrb_value
-eval_merge_lvar_hook(mrb_state *mrb, mrb_value dummy_self)
-{
-  const mrb_callinfo *orig_ci = &mrb->c->ci[1];
-  const struct RProc *orig_proc = orig_ci->proc;
-  const mrb_irep *orig_irep = orig_proc->body.irep;
-  int orig_nlocals = orig_irep->nlocals;
-
-  if (orig_nlocals > 1) {
-    struct RProc *proc = (struct RProc *)orig_proc->upper;
-    struct REnv *env = MRB_PROC_ENV(orig_proc);
-    eval_merge_lvar(mrb, (mrb_irep *)proc->body.irep, env,
-                    orig_nlocals - 1, orig_irep->lv,
-                    mrb->c->ci->stack + 3 /* hook proc + exc + ret val */);
-  }
-
-  mrb_value exc = mrb->c->ci->stack[1];
-  if (!mrb_nil_p(exc)) {
-    mrb_exc_raise(mrb, exc);
-  }
-
-  return mrb->c->ci->stack[2];
+  return mrb_exec_irep(mrb, self, proc);
 }
 
 static mrb_value
@@ -178,19 +147,15 @@ f_eval(mrb_state *mrb, mrb_value self)
   const char *file = NULL;
   mrb_int line = 1;
   struct RProc *proc;
-  mrb_func_t posthook = NULL;
 
   mrb_get_args(mrb, "s|ozi", &s, &len, &binding, &file, &line);
 
   proc = create_proc_from_string(mrb, s, len, binding, file, line);
   if (!mrb_nil_p(binding)) {
     self = mrb_iv_get(mrb, binding, MRB_SYM(recv));
-    if (mrb_env_p(mrb_iv_get(mrb, binding, MRB_SYM(env)))) {
-      posthook = eval_merge_lvar_hook;
-    }
   }
   mrb_assert(!MRB_PROC_CFUNC_P(proc));
-  return exec_irep(mrb, self, proc, posthook);
+  return exec_irep(mrb, self, proc);
 }
 
 static mrb_value
@@ -210,7 +175,7 @@ f_instance_eval(mrb_state *mrb, mrb_value self)
     MRB_PROC_SET_TARGET_CLASS(proc, mrb_class_ptr(cv));
     mrb_assert(!MRB_PROC_CFUNC_P(proc));
     mrb_vm_ci_target_class_set(mrb->c->ci, mrb_class_ptr(cv));
-    return exec_irep(mrb, self, proc, NULL);
+    return exec_irep(mrb, self, proc);
   }
   else {
     mrb_get_args(mrb, "");
@@ -233,7 +198,7 @@ f_class_eval(mrb_state *mrb, mrb_value self)
     MRB_PROC_SET_TARGET_CLASS(proc, mrb_class_ptr(self));
     mrb_assert(!MRB_PROC_CFUNC_P(proc));
     mrb_vm_ci_target_class_set(mrb->c->ci, mrb_class_ptr(self));
-    return exec_irep(mrb, self, proc, NULL);
+    return exec_irep(mrb, self, proc);
   }
   else {
     mrb_get_args(mrb, "");
diff --git a/mrbgems/mruby-method/src/method.c b/mrbgems/mruby-method/src/method.c
index 7410f007e..02131050d 100644
--- a/mrbgems/mruby-method/src/method.c
+++ b/mrbgems/mruby-method/src/method.c
@@ -7,7 +7,7 @@
 #include "mruby/presym.h"
 
 mrb_noreturn void mrb_method_missing(mrb_state *mrb, mrb_sym name, mrb_value self, mrb_value args);
-mrb_value mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook);
+mrb_value mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p);
 
 static mrb_value
 args_shift(mrb_state *mrb)
@@ -242,7 +242,7 @@ mcall(mrb_state *mrb, mrb_value self, mrb_value recv)
   mrb->c->ci->mid = mid;
   mrb->c->ci->u.target_class = tc;
 
-  return mrb_exec_irep(mrb, recv, proc, NULL);
+  return mrb_exec_irep(mrb, recv, proc);
 }
 
 static mrb_value
diff --git a/src/proc.c b/src/proc.c
index 2717cd610..1d5a4aa76 100644
--- a/src/proc.c
+++ b/src/proc.c
@@ -417,7 +417,14 @@ mrb_proc_merge_lvar(mrb_state *mrb, mrb_irep *irep, struct REnv *env, int num, c
   mrb_sym *destlv = (mrb_sym*)irep->lv + irep->nlocals - 1 /* self */;
   mrb_value *destst = env->stack + irep->nlocals;
   memmove(destlv, lv, sizeof(mrb_sym) * num);
-  memmove(destst, stack, sizeof(mrb_value) * num);
+  if (stack) {
+    memmove(destst, stack, sizeof(mrb_value) * num);
+  }
+  else {
+    for (int i = num; i > 0; i--, destst++) {
+      *destst = mrb_nil_value();
+    }
+  }
   irep->nlocals += num;
   irep->nregs = irep->nlocals;
   MRB_ENV_SET_LEN(env, irep->nlocals);
diff --git a/src/vm.c b/src/vm.c
index a6211c118..877057bd6 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -526,68 +526,8 @@ mrb_funcall_argv(mrb_state *mrb, mrb_value self, mrb_sym mid, mrb_int argc, cons
   return mrb_funcall_with_block(mrb, self, mid, argc, argv, mrb_nil_value());
 }
 
-#define DECOMPOSE32(n) (((n) >> 24) & 0xff), (((n) >> 16) & 0xff), (((n) >> 8) & 0xff), (((n) >> 0) & 0xff)
-#define CATCH_HANDLER_MAKE_BYTECODE(t, b, e, j) t, DECOMPOSE32(b), DECOMPOSE32(e), DECOMPOSE32(j)
-#define CATCH_HANDLER_NUM_TO_BYTE(n) ((n) * sizeof(struct mrb_irep_catch_handler))
-
-static void
-exec_irep_prepare_posthook(mrb_state *mrb, mrb_callinfo *ci, int nregs, mrb_func_t posthook)
-{
-  /*
-   *  stack: [proc, errinfo, return value by called proc]
-   *
-   *  begin
-   *    OP_NOP        # A dummy instruction built in to make the catch handler react.
-   *  ensure
-   *    OP_EXCEPT R1  # Save the exception object.
-   *    OP_CALL       # Call a C function for the hook.
-   *                  # The stack is kept as it is in the called proc.
-   *                  # The exception will be rethrown within the hook function.
-   *  end
-   */
-  static const mrb_code hook_iseq[] = {
-    OP_NOP,
-    OP_EXCEPT, 1,
-    OP_CALL,
-    CATCH_HANDLER_MAKE_BYTECODE(MRB_CATCH_ENSURE, 0, 1, 1),
-  };
-  static const mrb_irep hook_irep = {
-    1, 3, 1, MRB_IREP_STATIC, hook_iseq,
-    NULL, NULL, NULL, NULL, NULL,
-    sizeof(hook_iseq) / sizeof(hook_iseq[0]) - CATCH_HANDLER_NUM_TO_BYTE(1),
-    0, 0, 0, 0
-  };
-  static const struct RProc hook_caller = {
-    NULL, NULL, MRB_TT_PROC, MRB_GC_RED, MRB_FL_OBJ_IS_FROZEN, { &hook_irep }, NULL, { NULL }
-  };
-
-  struct RProc *hook = mrb_proc_new_cfunc(mrb, posthook);
-  int acc = 2;
-  memmove(ci->stack + acc, ci->stack, sizeof(mrb_value) * nregs);
-  ci->stack[0] = mrb_obj_value(hook);
-  ci->stack[1] = mrb_nil_value();
-  mrb_callinfo hook_ci = { 0, 0, ci->acc, &hook_caller, ci->stack, &hook_iseq[1], { NULL } };
-  ci = cipush(mrb, acc, acc, NULL, ci[0].proc, ci[0].mid, ci[0].argc);
-  ci->u.env = ci[-1].u.env;
-  ci[-1] = hook_ci;
-}
-
-/*
- * If `posthook` is given, `posthook` will be called even if an
- * exception or global jump occurs in `p`. Exception or global jump objects
- * are stored in `mrb->c->stack[1]` and should be rethrown in `posthook`.
- *
- *    if (!mrb_nil_p(mrb->c->stack[1])) {
- *      mrb_exc_raise(mrb, mrb->c->stack[1]);
- *    }
- *
- * If you want to return the return value by `proc` as it is, please do
- * `return mrb->c->stack[2]`.
- *
- * However, if `proc` is a C function, it will be ignored.
- */
 static mrb_value
-exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook)
+exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p)
 {
   mrb_callinfo *ci = mrb->c->ci;
   int keep, nregs;
@@ -600,17 +540,12 @@ exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook)
   nregs = p->body.irep->nregs;
   if (ci->argc < 0) keep = 3;
   else keep = ci->argc + 2;
-  int extra = posthook ? (2 /* hook proc + errinfo */) : 0;
   if (nregs < keep) {
-    mrb_stack_extend(mrb, keep + extra);
+    mrb_stack_extend(mrb, keep);
   }
   else {
-    mrb_stack_extend(mrb, nregs + extra);
-    stack_clear(ci->stack+keep, nregs-keep + extra);
-  }
-
-  if (posthook) {
-    exec_irep_prepare_posthook(mrb, ci, (nregs < keep ? keep : nregs), posthook);
+    mrb_stack_extend(mrb, nregs);
+    stack_clear(ci->stack+keep, nregs-keep);
   }
 
   cipush(mrb, 0, 0, NULL, NULL, 0, 0);
@@ -619,11 +554,11 @@ exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook)
 }
 
 mrb_value
-mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p, mrb_func_t posthook)
+mrb_exec_irep(mrb_state *mrb, mrb_value self, struct RProc *p)
 {
   mrb_callinfo *ci = mrb->c->ci;
   if (ci->acc >= 0) {
-    return exec_irep(mrb, self, p, posthook);
+    return exec_irep(mrb, self, p);
   }
   else {
     mrb_value ret;
@@ -706,7 +641,7 @@ mrb_f_send(mrb_state *mrb, mrb_value self)
     }
     return MRB_METHOD_CFUNC(m)(mrb, self);
   }
-  return exec_irep(mrb, self, MRB_METHOD_PROC(m), NULL);
+  return exec_irep(mrb, self, MRB_METHOD_PROC(m));
 }
 
 static mrb_value
@@ -884,7 +819,7 @@ 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 exec_irep(mrb, self, p, NULL);
+  return exec_irep(mrb, self, p);
 }
 
 static struct RBreak*