fix a B-stack leak: PermSort works

interpreter/code.c

@@ -613,7 +613,10 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr)
             placeholder();
             exec(((IfEntry*) expr)->cond, frame_ptr, stack_top_a);
             Thunk* cond = pop_a();
-               
+            
+            // safe to do it before read as nothing can overwrite it inbetween
+            stack_top_b--;
+            
             if (readB(cond)) {
                 expr = ((IfEntry*) expr)->texpr;
                 continue;                

tests/PermSort.exp

+[1]
\ No newline at end of file

tests/broken/Queens2.sapl

-main = Queens2.Start
-Queens2.Start::I = Queens2.nqueens 11
-Queens2.nqueens::I !n_0::I = Queens2.len (Queens2.solve n_0 (Queens2.replicate n_0 Flite.Nil))
-:: Flite.List = Flite.Nil | Flite.Cons a1 a2
-Queens2.replicate !n_0::I x_1 = if (eqI n_0 0) Flite.Nil (Flite.Cons x_1 (Queens2.replicate (subI n_0 1) x_1))
-Queens2.solve !n_0::I mask_1 = if (eqI n_0 0) (Flite.Cons Flite.Nil Flite.Nil) (Queens2.concatMap (Queens2.sol (subI n_0 1)) (Queens2.fill mask_1))
-Queens2.fill !_x_0 = select _x_0 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> Queens2.append (Queens2.lrd x_1_0 xs_1_1) (Queens2.map (Flite.Cons x_1_0) (Queens2.fill xs_1_1))) 
-Queens2.map f_0 !_x_1 = select _x_1 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> Flite.Cons (f_0 x_1_0) (Queens2.map f_0 xs_1_1)) 
-Queens2.lrd !_x_0 ys_1 = select _x_0 (Flite.Nil -> Flite.Cons (Flite.Cons (Flite.Cons Queens2.l (Flite.Cons Queens2.r (Flite.Cons Queens2.d Flite.Nil))) ys_1) Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> Flite.Nil) 
-Queens2.d::I = 2
-Queens2.r::I = 1
-Queens2.l::I = 0
-Queens2.append !_x_0 ys_1 = select _x_0 (Flite.Nil -> ys_1) (Flite.Cons x_1_0 xs_1_1 -> Flite.Cons x_1_0 (Queens2.append xs_1_1 ys_1)) 
-Queens2.sol !n_0::I row_1 = Queens2.map (Flite.Cons row_1) (Queens2.solve n_0 (Queens2.next row_1))
-Queens2.next !mask_0 = Queens2.merge (Queens2.merge (Queens2.down mask_0) (Queens2.left mask_0)) (Queens2.right mask_0)
-Queens2.right xs_0 = Flite.Cons Flite.Nil (Queens2.map (Queens2.onep (Queens2.eq_22 Queens2.r)) xs_0)
-Queens2.eq_22::B !x_0::I !y_1::I = eqI x_0 y_1
-Queens2.onep p_0 !_x_1 = select _x_1 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> if (p_0 x_1_0) (Flite.Cons x_1_0 Flite.Nil) (Queens2.onep p_0 xs_1_1)) 
-Queens2.left !xs_0 = Queens2.map (Queens2.onep (Queens2.eq_22 Queens2.l)) (Queens2.tail xs_0)
-Queens2.tail !_x_0 = select _x_0 (Flite.Cons x_1_0 xs_1_1 -> xs_1_1) 
-Queens2.down !xs_0 = Queens2.map (Queens2.onep (Queens2.eq_22 Queens2.d)) xs_0
-Queens2.merge !_x_0 ys_1 = select _x_0 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> select ys_1 (Flite.Nil -> Flite.Cons x_1_0 xs_1_1) (Flite.Cons y_2_0 ys_2_1 -> Flite.Cons (Queens2.append x_1_0 y_2_0) (Queens2.merge xs_1_1 ys_2_1)) ) 
-Queens2.concatMap f_0 !_x_1 = select _x_1 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> Queens2.append (f_0 x_1_0) (Queens2.concatMap f_0 xs_1_1)) 
-Queens2.len::I !_x_0 = select _x_0 (Flite.Nil -> 0) (Flite.Cons x_1_0 xs_1_1 -> addI 1 (Queens2.len xs_1_1)) 

tests/postponed/PermSort.sapl

-main = PermSort.Start
-PermSort.Start::I = PermSort.head (PermSort.permSort_12 (Flite.Cons 10 (Flite.Cons 9 (Flite.Cons 8 (Flite.Cons 7 (Flite.Cons 6 (Flite.Cons 5 (Flite.Cons 4 (Flite.Cons 3 (Flite.Cons 2 (Flite.Cons 1 Flite.Nil)))))))))))
-:: Flite.List = Flite.Nil | Flite.Cons a1 a2
-PermSort.permSort_12 !xs_0 = PermSort.head (PermSort.filter PermSort.ord_13 (PermSort.perm xs_0))
-PermSort.perm !_x_0 = select _x_0 (Flite.Nil -> Flite.Cons Flite.Nil Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> PermSort.concatMap (PermSort.place x_1_0) (PermSort.perm xs_1_1)) 
-PermSort.place x_0 !_x_1 = select _x_1 (Flite.Nil -> Flite.Cons (Flite.Cons x_0 Flite.Nil) Flite.Nil) (Flite.Cons y_1_0 ys_1_1 -> Flite.Cons (Flite.Cons x_0 (Flite.Cons y_1_0 ys_1_1)) (PermSort.map (Flite.Cons y_1_0) (PermSort.place x_0 ys_1_1))) 
-PermSort.map f_0 !_x_1 = select _x_1 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> Flite.Cons (f_0 x_1_0) (PermSort.map f_0 xs_1_1)) 
-PermSort.concatMap f_0 !_x_1 = select _x_1 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> PermSort.append (f_0 x_1_0) (PermSort.concatMap f_0 xs_1_1)) 
-PermSort.append !_x_0 ys_1 = select _x_0 (Flite.Nil -> ys_1) (Flite.Cons x_1_0 xs_1_1 -> Flite.Cons x_1_0 (PermSort.append xs_1_1 ys_1)) 
-PermSort.ord_13::B !_x_0 = select _x_0 (Flite.Nil -> True) (Flite.Cons x_1_0 _x_1_1 -> select _x_1_1 (Flite.Nil -> True) (Flite.Cons y_2_0 ys_2_1 -> PermSort.and (<{PermSort.<=_14}> x_1_0 y_2_0) (PermSort.ord_13 (Flite.Cons y_2_0 ys_2_1))) ) 
-<{PermSort.<=_14}>::B !x_0::I !y_1::I = not (ltI y_1 x_0)
-PermSort.and::B !_x_0::B x_1::B = if _x_0 x_1 False
-PermSort.filter p_0 !_x_1 = select _x_1 (Flite.Nil -> Flite.Nil) (Flite.Cons x_1_0 xs_1_1 -> if (p_0 x_1_0) (Flite.Cons x_1_0 (PermSort.filter p_0 xs_1_1)) (PermSort.filter p_0 xs_1_1)) 
-PermSort.head !_x_0 = select _x_0 (Flite.Cons x_1_0 xs_1_1 -> x_1_0) 

tests/postponed/reptwice.sapl

 main = Benchmarks.Start
-Benchmarks.Start = Benchmarks.reptwice 400
-Benchmarks.reptwice !n_0 = Benchmarks.sumrem (Benchmarks.map1 Benchmarks.tinc_90 (Benchmarks.fromto 1 n_0))
-Benchmarks.fromto !n_0 !m_1 = Benchmarks.take1 (add (sub m_1 n_0) 1) (Benchmarks.fr n_0)
-Benchmarks.fr n_0 = Benchmarks.Cons n_0 (Benchmarks.fr (add n_0 1))
+Benchmarks.Start::I = Benchmarks.reptwice 400
+Benchmarks.reptwice::I !n_0::I = Benchmarks.sumrem (Benchmarks.map1 Benchmarks.tinc_90 (Benchmarks.fromto 1 n_0))
+Benchmarks.fromto !n_0::I !m_1::I = Benchmarks.take1 (addI (subI m_1 n_0) 1) (Benchmarks.fr n_0)
+Benchmarks.fr n_0::I = Benchmarks.Cons n_0 (Benchmarks.fr (addI n_0 1))
 :: Benchmarks.List1 = Benchmarks.Nill | Benchmarks.Cons a1 a2
-Benchmarks.take1 n_0 !_x_1 = select _x_1 (Benchmarks.Nill -> Benchmarks.Nill) (Benchmarks.Cons x_1_0 xs_1_1 -> if (eqI n_0 0) Benchmarks.Nill (Benchmarks.Cons x_1_0 (Benchmarks.take1 (sub n_0 1) xs_1_1))) 
-Benchmarks.tinc_90 n_0 = StdFunc.twice StdFunc.twice StdFunc.twice StdFunc.twice Benchmarks.inc_91 n_0
-Benchmarks.inc_91 !x_0 = add x_0 1
+Benchmarks.take1 n_0::I !_x_1 = select _x_1 (Benchmarks.Nill -> Benchmarks.Nill) (Benchmarks.Cons x_1_0 xs_1_1 -> if (eqI n_0 0) Benchmarks.Nill (Benchmarks.Cons x_1_0 (Benchmarks.take1 (subI n_0 1) xs_1_1))) 
+Benchmarks.tinc_90::I n_0::I = StdFunc.twice StdFunc.twice StdFunc.twice StdFunc.twice Benchmarks.inc_91 n_0
+Benchmarks.inc_91::I !x_0::I = addI x_0 1
 StdFunc.twice !f_0 x_1 = f_0 (f_0 x_1)
 Benchmarks.map1 f_0 !_x_1 = select _x_1 (Benchmarks.Nill -> Benchmarks.Nill) (Benchmarks.Cons x_1_0 xs_1_1 -> Benchmarks.Cons (f_0 x_1_0) (Benchmarks.map1 f_0 xs_1_1)) 
-Benchmarks.sumrem !_x_0 = select _x_0 (Benchmarks.Nill -> 0) (Benchmarks.Cons a_1_0 as_1_1 -> mod (add a_1_0 (Benchmarks.sumrem as_1_1)) 7) 
+Benchmarks.sumrem::I !_x_0 = select _x_0 (Benchmarks.Nill -> 0) (Benchmarks.Cons a_1_0 as_1_1 -> mod (addI a_1_0 (Benchmarks.sumrem as_1_1)) 7)