klisp

commit 42c59c8b753ee03171ce779a12b2b47a3e1273d6
parent 36db428b30a3be0056a1fd3d3302735ef241c1e5
Author: Andres Navarro <canavarro82@gmail.com>
Date:   Sat, 16 Apr 2011 10:53:32 -0300

Bugfix: tails wan't being properly protected in transpose. Simplified a little with the use of the vars stack.

Diffstat:
M
src/kgcombiners.c
 | 
13
+++++++++----
M
src/kgcombiners.h
 | 
4
++++

2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/src/kgcombiners.c b/src/kgcombiners.c
@@ -321,7 +321,13 @@ TValue map_for_each_transpose(klisp_State *K, TValue lss,
     TValue lp = kget_dummy3(K);
     TValue lap = lp;
 
+    TValue cars = KNIL; /* put something for GC */
     TValue tail = lss;
+
+    /* GC: both cars & tail vary in each loop, to protect them we need
+       the vars stack */
+    krooted_vars_push(K, &cars);
+    krooted_vars_push(K, &tail);
     
     /* Loop over list of lists, creating a list of cars and 
        a list of cdrs, accumulate the list of cars and loop
@@ -339,11 +345,8 @@ TValue map_for_each_transpose(klisp_State *K, TValue lss,
 
 	while(pairs--) {
 	    /* accumulate cars and replace tail with cdrs */
-	    TValue cars = 
-		map_for_each_get_cars_cdrs(K, &tail, app_apairs, app_cpairs);
-	    krooted_tvs_push(K, cars);
+	    cars = map_for_each_get_cars_cdrs(K, &tail, app_apairs, app_cpairs);
 	    TValue np = kcons(K, cars, KNIL);
-	    krooted_tvs_pop(K);
 	    kset_cdr(lp, np);
 	    lp = np;
 	}
@@ -359,6 +362,8 @@ TValue map_for_each_transpose(klisp_State *K, TValue lss,
 	}
     }
 
+    krooted_vars_pop(K);
+    krooted_vars_pop(K);
     return kcutoff_dummy3(K);
 }
 
diff --git a/src/kgcombiners.h b/src/kgcombiners.h
@@ -54,12 +54,16 @@ void map_for_each_get_metrics(
 
 /* Return two lists, isomorphic to lss: one list of cars and one list
    of cdrs (replacing the value of lss) */
+/* GC: Assumes lss is rooted, uses dummys 2 & 3 */
 TValue map_for_each_get_cars_cdrs(klisp_State *K, TValue *lss, 
 				  int32_t apairs, int32_t cpairs);
 
 /* Transpose lss so that the result is a list of lists, each one having
    metrics (app_apairs, app_cpairs). The metrics of the returned list
    should be (res_apairs, res_cpairs) */
+
+/* GC: Assumes lss is rooted, uses dummys 1, & 
+   (through get_cars_cdrs, 2, 3) */
 TValue map_for_each_transpose(klisp_State *K, TValue lss, 
 			      int32_t app_apairs, int32_t app_cpairs, 
 			      int32_t res_apairs, int32_t res_cpairs);