klisp

commit 26f445bbbff6aa1df91bcc20b7d4250eabac7f1b
parent 57cd4aa9819801558b14d8ae0c5d51f353d07396
Author: Andres Navarro <canavarro82@gmail.com>
Date:   Sat, 16 Apr 2011 21:46:55 -0300

Bugfix: unbalanced push/pop in gc rooting.

Diffstat:
M
src/krepl.c
 | 
10
++++++----
M
src/kstate.h
 | 
8
+++++++-

2 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/src/krepl.c b/src/krepl.c
@@ -68,9 +68,10 @@ void eval_cfn(klisp_State *K, TValue *xparams, TValue obj)
 void loop_fn(klisp_State *K, TValue *xparams, TValue obj);
 
 /* this is called from both loop_fn and error_fn */
-/* GC: assumes denv is rooted */
+/* GC: assumes denv is NOT rooted */
 inline void create_loop(klisp_State *K, TValue denv)
 {
+    krooted_tvs_push(K, denv);
     TValue loop_cont = 
 	kmake_continuation(K, K->root_cont, &loop_fn, 1, denv);
     krooted_tvs_push(K, loop_cont);
@@ -78,8 +79,9 @@ inline void create_loop(klisp_State *K, TValue denv)
     krooted_tvs_pop(K); /* in eval cont */
     krooted_tvs_push(K, eval_cont);
     TValue read_cont = kmake_continuation(K, eval_cont, &read_fn, 0);
-    krooted_tvs_pop(K);
     kset_cc(K, read_cont);
+    krooted_tvs_pop(K);
+    krooted_tvs_pop(K);
     kapply_cc(K, KINERT);
 }
 
@@ -144,8 +146,8 @@ void kinit_repl(klisp_State *K)
 
     krooted_tvs_pop(K);
     krooted_tvs_pop(K);
+    krooted_tvs_pop(K);
 
-    /* don't yet pop std_env */
+    /* GC: create_loop will root std_env */
     create_loop(K, std_env);
-    krooted_tvs_pop(K);
 }
diff --git a/src/kstate.h b/src/kstate.h
@@ -34,7 +34,7 @@ typedef struct {
     int32_t saved_col;
 } ksource_info_t;
 
-#define GC_PROTECT_SIZE 32
+#define GC_PROTECT_SIZE 6 /* XXX was 32 */
 
 /* NOTE: when adding TValues here, remember to add them to
    markroot in kgc.c!! */
@@ -341,6 +341,9 @@ typedef void (*klisp_Ofunc) (klisp_State *K, TValue *ud, TValue ptree,
 */
 inline void klispS_apply_cc(klisp_State *K, TValue val)
 {
+    klisp_assert(K->rooted_tvs_top == 0);
+    klisp_assert(K->rooted_vars_top == 0);
+
     K->next_obj = K->curr_cont; /* save it from GC */
     Continuation *cont = tv2cont(K->curr_cont);
     K->next_func = cont->fn;
@@ -370,6 +373,9 @@ inline void klispS_set_cc(klisp_State *K, TValue new_cont)
 inline void klispS_tail_call(klisp_State *K, TValue top, TValue ptree, 
 			     TValue env)
 {
+    klisp_assert(K->rooted_tvs_top == 0);
+    klisp_assert(K->rooted_vars_top == 0);
+
     K->next_obj = top; /* save it from GC */
     Operative *op = tv2op(top);
     K->next_func = op->fn;