Simplify frame logic.

frame_layout.h

@@ -7,88 +7,65 @@ struct closure {
   stack_ptr env;
 };
 
-struct continuation {
+union frame_entry {
+  struct closure closure;
+  jv localvar;
+};
+
+struct frame {
   struct bytecode* bc;
   stack_ptr env;
   stack_ptr retdata;
   uint16_t* retaddr;
+  /* bc->nclosures closures followed by bc->nlocals local variables */
+  union frame_entry entries[0]; 
 };
 
-typedef union frame_elem {
-  struct continuation cont;
-  struct closure closure;
-  jv jsonval;
-} *frame_ptr;
-
-/*
- * Frame layout
- * fr[0] - FORKABLE_STACK_HEADER (next pointer)
- * fr[1] - self (used to store return addresses, etc)
- * fr[2...nclosures+2] - closure params
- * fr[nclosures+2..nclosures+nlocals+2] - local variables
- */
-
 static int frame_size(struct bytecode* bc) {
-  return sizeof(union frame_elem) * (bc->nclosures + bc->nlocals + 2);
+  return sizeof(struct frame) + sizeof(union frame_entry) * (bc->nclosures + bc->nlocals);
 }
 
-static struct continuation* frame_self(frame_ptr fr) {
-  return &fr[1].cont;
-}
-
-static struct closure* frame_closure_arg(frame_ptr fr, int closure) {
+static struct closure* frame_closure_arg(struct frame* fr, int closure) {
   assert(closure >= 0);
-  assert(closure < frame_self(fr)->bc->nclosures);
-  return &fr[2+closure].closure;
+  assert(closure < fr->bc->nclosures);
+  return &fr->entries[closure].closure;
 }
 
-static jv* frame_local_var(frame_ptr fr, int var) {
+static jv* frame_local_var(struct frame* fr, int var) {
   assert(var >= 0);
-  assert(var < frame_self(fr)->bc->nlocals);
-  return &fr[2 + frame_self(fr)->bc->nclosures + var].jsonval;
+  assert(var < fr->bc->nlocals);
+  return &fr->entries[fr->bc->nclosures + var].localvar;
 }
 
-
-static frame_ptr frame_current(struct stack* stk, stack_ptr idx) {
-  frame_ptr fp = stack_block(stk, idx);
+static struct frame* frame_current(struct stack* stk, stack_ptr idx) {
+  struct frame* fp = stack_block(stk, idx);
 
   stack_ptr next = *stack_block_next(stk, idx);
   if (next) {
-    frame_ptr fpnext = stack_block(stk, next);
-    struct bytecode* bc = frame_self(fpnext)->bc;
-    assert(frame_self(fp)->retaddr >= bc->code && frame_self(fp)->retaddr < bc->code + bc->codelen);
+    struct frame* fpnext = stack_block(stk, next);
+    struct bytecode* bc = fpnext->bc;
+    assert(fp->retaddr >= bc->code && fp->retaddr < bc->code + bc->codelen);
   } else {
-    assert(frame_self(fp)->retaddr == 0);
+    assert(fp->retaddr == 0);
   }
   return fp;
 }
 
-static struct bytecode* frame_current_bytecode(struct stack* stk, stack_ptr curr) {
-  return frame_self(frame_current(stk, curr))->bc;
-}
-static uint16_t** frame_current_retaddr(struct stack* stk, stack_ptr curr) {
-  return &frame_self(frame_current(stk, curr))->retaddr;
-}
-
-static stack_ptr frame_get_parent(struct stack* stk, stack_ptr fr) {
-  return frame_self(stack_block(stk, fr))->env;
-}
-
 static stack_ptr frame_get_level(struct stack* stk, stack_ptr fr, int level) {
   for (int i=0; i<level; i++) {
-    fr = frame_get_parent(stk, fr);
+    struct frame* fp = stack_block(stk, fr);
+    fr = fp->env;
   }
   return fr;
 }
 
 static stack_ptr frame_push(struct stack* stk, stack_ptr curr, struct closure cl, uint16_t* retaddr, stack_ptr datastk) {
   stack_ptr fpidx = stack_push_block(stk, curr, frame_size(cl.bc));
-  frame_ptr fp = stack_block(stk, fpidx);
-  struct continuation* cc = frame_self(fp);
-  cc->bc = cl.bc;
-  cc->env = cl.env;
-  cc->retdata = datastk;
-  cc->retaddr = retaddr;
+  struct frame* fp = stack_block(stk, fpidx);
+  fp->bc = cl.bc;
+  fp->env = cl.env;
+  fp->retdata = datastk;
+  fp->retaddr = retaddr;
   for (int i=0; i<cl.bc->nlocals; i++) {
     *frame_local_var(fp, i) = jv_invalid();
   }
@@ -96,14 +73,14 @@ static stack_ptr frame_push(struct stack* stk, stack_ptr curr, struct closure cl
 }
 
 static stack_ptr frame_pop(struct stack* stk, stack_ptr curr) {
-  frame_ptr fp = frame_current(stk, curr);
+  struct frame* fp = frame_current(stk, curr);
   if (stack_pop_will_free(stk, curr)) {
-    int nlocals = frame_self(fp)->bc->nlocals;
+    int nlocals = fp->bc->nlocals;
     for (int i=0; i<nlocals; i++) {
       jv_free(*frame_local_var(fp, i));
     }
   }
-  return stack_pop_block(stk, curr, frame_size(frame_self(fp)->bc));
+  return stack_pop_block(stk, curr, frame_size(fp->bc));
 }
 
 #endif