From 19db4bb6b2b3f26adaff07eda2624b957c31dde3 Mon Sep 17 00:00:00 2001
From: Yuichi Nishiwaki <yuichi.nishiwaki@gmail.com>
Date: Sun, 2 Feb 2014 12:27:48 +0900
Subject: [PATCH] rest array got by pic_get_args has a dynamic extent; that is,
 we cannot store it to a heap object when we are going to rewind that stack
 and restore an old continuation.

---
 include/picrin/cont.h |  4 ++--
 src/cont.c            | 25 +++++++++++++++++++------
 src/gc.c              |  4 +---
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/include/picrin/cont.h b/include/picrin/cont.h
index 6bb18623..c08a2830 100644
--- a/include/picrin/cont.h
+++ b/include/picrin/cont.h
@@ -30,8 +30,7 @@ struct pic_cont {
   struct pic_object *arena[PIC_ARENA_SIZE];
   int arena_idx;
 
-  size_t argc;
-  pic_value *argv;
+  pic_value results;
 };
 
 #define PIC_BLK_INCREF(pic,blk) do {		\
@@ -54,6 +53,7 @@ struct pic_cont {
 pic_value pic_callcc(pic_state *, struct pic_proc *);
 pic_value pic_values(pic_state *, size_t, ...);
 pic_value pic_values_by_array(pic_state *, size_t, pic_value *);
+pic_value pic_values_by_list(pic_state *, pic_value);
 
 #if defined(__cplusplus)
 }
diff --git a/src/cont.c b/src/cont.c
index 3164ee6d..2da3fd3d 100644
--- a/src/cont.c
+++ b/src/cont.c
@@ -9,6 +9,7 @@
 #include "picrin.h"
 #include "picrin/proc.h"
 #include "picrin/cont.h"
+#include "picrin/pair.h"
 
 static void save_cont(pic_state *, struct pic_cont **);
 static void restore_cont(pic_state *, struct pic_cont *);
@@ -61,8 +62,7 @@ save_cont(pic_state *pic, struct pic_cont **c)
   cont->arena_idx = pic->arena_idx;
   memcpy(cont->arena, pic->arena, sizeof(struct pic_object *) * PIC_ARENA_SIZE);
 
-  cont->argc = 0;
-  cont->argv = NULL;
+  cont->results = pic_undef_value();
 }
 
 static void
@@ -142,8 +142,7 @@ cont_call(pic_state *pic)
   pic_get_args(pic, "*", &argc, &argv);
 
   cont = (struct pic_cont *)pic_ptr(proc->env->values[0]);
-  cont->argc = argc;
-  cont->argv = argv;
+  cont->results = pic_list_by_array(pic, argc, argv);
 
   /* execute guard handlers */
   walk_to_block(pic, pic->blk, cont->blk);
@@ -158,8 +157,7 @@ pic_callcc(pic_state *pic, struct pic_proc *proc)
 
   save_cont(pic, &cont);
   if (setjmp(cont->jmp)) {
-    printf("%d\n", cont->argc);
-    return pic_values_from_array(pic, cont->argc, cont->argv);
+    return pic_values_by_list(pic, cont->results);
   }
   else {
     struct pic_proc *c;
@@ -205,6 +203,21 @@ pic_values_by_array(pic_state *pic, size_t argc, pic_value *argv)
   return argc == 0 ? pic_none_value() : pic->ci->fp[0];
 }
 
+pic_value
+pic_values_by_list(pic_state *pic, pic_value list)
+{
+  pic_value v;
+  size_t i;
+
+  i = 0;
+  pic_for_each (v, list) {
+    pic->ci->fp[i++] = v;
+  }
+  pic->ci->fp[i] = pic_undef_value();
+
+  return pic_nil_p(list) ? pic_none_value() : pic->ci->fp[0];
+}
+
 static pic_value
 pic_cont_callcc(pic_state *pic)
 {
diff --git a/src/gc.c b/src/gc.c
index f37e045b..4099f42b 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -386,9 +386,7 @@ gc_mark_object(pic_state *pic, struct pic_object *obj)
     }
 
     /* result values */
-    for (i = 0; i < cont->argc; ++i) {
-      gc_mark(pic, cont->argv[i]);
-    }
+    gc_mark(pic, cont->results);
     break;
   }
   case PIC_TT_SYNTAX: {