in transition to the new stack frame. BROKEN

interpreter/code.c

@@ -15,15 +15,14 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
     {
         switch (expr->type) {
         case CT_LIT:
-            stack_top_a = root_frame_ptr; 
-            push_a(updateT(target, &((LitEntry*) expr)->thunk));
+            prepare_return(root_frame_ptr, 
+                    updateT(target, &((LitEntry*) expr)->thunk));
             return;
         case CT_VAR:
-            stack_top_a = root_frame_ptr;     
-            
             if (expr->local_type == VAR_LOCAL) {
                 Thunk* thunk = forward_to(target, local(frame_ptr, ((VarEntry*) expr)->index));
-                if(force) push_a(eval(thunk)); else push_a(thunk);
+                if(force) thunk = eval(thunk);
+                prepare_return(root_frame_ptr, thunk);
                 return;
             }else{
                 Desc* slice = get_slice(((VarEntry*) expr)->f, 0);
@@ -34,8 +33,9 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
                     continue;
                 }
                 else
-                {
-                    push_a(updateF(target, get_slice(((VarEntry*) expr)->f, 0)));
+                {                    
+                    prepare_return(root_frame_ptr, 
+                            updateF(target, get_slice(((VarEntry*) expr)->f, 0)));
                     return;
                 }
             }
@@ -45,7 +45,6 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
             // TODO: enforce strictness in ADT/Record
 
             VarEntry* var = &((AppEntry*) expr)->var;
-            Thunk* thunk;
 
             if (var->base.local_type == VAR_LOCAL) 
             {
@@ -55,7 +54,7 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
                         get_slice(basethunk->desc->type == FT_SLICE ?
                                   ((SliceEntry*) basethunk->desc)->forward_ptr : basethunk->desc, basethunk->desc->arity + expr->nr_args);
 
-                thunk = updateF(target, slice);
+                Thunk* thunk = updateF(target, slice);
 
                 assert(thunk->desc->arity == basethunk->desc->arity + expr->nr_args);            
 
@@ -64,29 +63,29 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
                 }
 
                 for (int i = 0; i < expr->nr_args; i++) {
+                    push_a(NULL);
                     exec(((AppEntry*) expr)->args[i], frame_ptr, stack_top_a, NULL, false);
                     thunk->_args[basethunk->desc->arity + i] = pop_a();
                 }
 
-                stack_top_a = root_frame_ptr;
-                push_a(thunk);
+                prepare_return(root_frame_ptr, thunk);
                 return;
             }
             else
             {
                 Desc* slice = get_slice(var->f, expr->nr_args);
-
+                
                 if (force && slice->type == FT_PRIM) {
                     Thunk args[expr->nr_args];
 
                     for (int i = 0; i < expr->nr_args; i++) {
+                        push_a(&args[i]);                        
                         exec(((AppEntry*) expr)->args[i], frame_ptr, stack_top_a, &args[i], true);
                     }
 
-                    thunk = ((PrimEntry*) slice)->exec(target);
+                    prepare_return(root_frame_ptr, 
+                            ((PrimEntry*) slice)->exec(target));
                     
-                    stack_top_a = root_frame_ptr;
-                    push_a(thunk);
                     return;
                 }
                 else if (force && slice->type == FT_FUN) {
@@ -94,6 +93,7 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
                     int new_frame_ptr = stack_top_a;
 
                     for (int i = 0; i < expr->nr_args; i++) {
+                        push_a(NULL);
                         exec(((AppEntry*) expr)->args[i], frame_ptr, stack_top_a, NULL, is_strict_fun_arg((FunEntry*) slice, i));
                     }
 
@@ -102,17 +102,17 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
                     continue;
                 }
                 else {
-                    thunk = updateF(target, slice);
+                    Thunk* thunk = updateF(target, slice);
 
                     assert(thunk->desc->arity == expr->nr_args);
 
                     for (int i = 0; i < expr->nr_args; i++) {
+                        push_a(NULL);
                         exec(((AppEntry*) expr)->args[i], frame_ptr, stack_top_a, NULL, false);
                         thunk->_args[i] = pop_a();
                     }
                     
-                    stack_top_a = root_frame_ptr;
-                    push_a(thunk);
+                    prepare_return(root_frame_ptr, thunk);
                     return;                    
                 }
             }
@@ -120,6 +120,7 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
         }
         case CT_SELECT:
         {
+            push_a(NULL);
             exec(((SelectEntry*) expr)->expr, frame_ptr, stack_top_a, NULL, true);
             Thunk* pattern = eval(pop_a());
 
@@ -128,6 +129,8 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
             for (int i = 0; i < expr->nr_cases; i++) {
                 SelectCaseEntry* caseEntry = &((SelectEntry*) expr)->cases[i];
 
+                assert(pattern->desc->type == FT_ADT);
+                
                 if (caseEntry->type == SC_CONS) {
                     // Pattern match
                     if ((Desc*) caseEntry->cons != pattern->desc) continue;
@@ -135,11 +138,7 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
                     // Put the constructor arguments to the stack if matches
                     for (int i = 0; i < pattern->desc->arity; i++) {
                         push_a(pattern->_args[i]);
-                    }
-                    
-                    handled = true;
-                    expr = caseEntry->body;
-                    break;                    
+                    }                  
                 }
                 else if (caseEntry->type == SC_LIT) {
                     printf("Exec: Unhandled entry type in CT_SELECT (SC_LIT)");
@@ -163,6 +162,7 @@ void exec(Code* expr, int frame_ptr, int root_frame_ptr, Thunk* target, bool for
             Thunk tmp;
             tmp.desc = (Desc*) __BOOL__;
 
+            push_a(&tmp);
             exec(((IfEntry*) expr)->cond, frame_ptr, stack_top_a, &tmp, true);
             Thunk* cond = eval(pop_a());
 

interpreter/debug.h

 #ifndef DEBUG_H
 #define	DEBUG_H
 
-//#define DEBUG
+#define DEBUG
 
 #ifndef DEBUG
 #define NDEBUG

interpreter/main.c

@@ -29,7 +29,7 @@ int main ( int argc, char *argv[] )
     init_desc();
     init_prim();
 
-    char* input = "..\\tests\\nfib.bsapl";
+    char* input = "..\\tests\\Braun.bsapl";
     
     if ( argc == 2 )
     {
@@ -84,6 +84,7 @@ int main ( int argc, char *argv[] )
     gettimeofday(&t1, NULL);
 #endif
         
+    push_a(NULL);
     exec(expr, stack_top_a, stack_top_a, NULL, true);    
     Thunk* res = eval(pop_a());
 

interpreter/mem.h

@@ -14,6 +14,7 @@ extern Thunk* stack_a[STACK_SIZE_A];
 #define push_a(r) stack_a[stack_top_a++]=(r)
 
 #define local(base, idx) stack_a[base+idx-1]
+#define prepare_return(base, r) stack_a[base-1]=(r); stack_top_a = base
 
 void init_mem();
 void print_stat();

interpreter/thunk.c

@@ -122,6 +122,7 @@ struct Thunk* eval(Thunk* thunk) {
     }
 
     if (thunk->desc->type == FT_FUN) {
+        push_a(thunk);
         int frame_ptr = stack_top_a;
 
         for (int i = 0; i < thunk->desc->arity; i++) {
@@ -138,7 +139,7 @@ struct Thunk* eval(Thunk* thunk) {
             push_a(thunk->_args[i]);
         }
 
-        ((PrimEntry*) thunk->desc)->exec(thunk);
+        thunk = ((PrimEntry*) thunk->desc)->exec(thunk);
 
         stack_top_a = frame_ptr;        
     }