Frame pointer points to local 0 instead of local 1

* libguile/frames.h: Change so that fp points at local 0 instead of
  local 1, and clean up a bit.
  (struct scm_vm_frame): Remove program, and rename stack to locals.
  (SCM_FRAME_DATA_ADDRESS): Remove; it was redundant with
  SCM_FRAME_LOWER_ADDRESS.
  (SCM_FRAME_STACK_ADDRESS): Remove; replace with the new
  SCM_FRAME_LOCALS_ADDRESS.
  (SCM_FRAME_UPPER_ADDRESS): Remove; unused.
  (SCM_FRAME_NUM_LOCALS, SCM_FRAME_PREVIOUS_SP): New defines.
  (SCM_FRAME_BYTE_CAST, SCM_FRAME_STACK_CAST): Remove; unused;
  (SCM_FRAME_LOCAL): New define, replaces SCM_FRAME_VARIABLE.
  (SCM_FRAME_PROGRAM): Add cautionary commentary.

* libguile/frames.c: Adapt static asserts.
  (scm_frame_num_locals, scm_frame_local_ref, scm_frame_local_set_x):
  Adapt.  This means that frame-local-ref 0 now returns the procedure.

* libguile/vm-engine.c (ALLOC_FRAME, RESET_FRAME)
  (FRAME_LOCALS_COUNT, LOCAL_REF, LOCAL_SET, RETURN_VALUE_LIST): Adapt
  to change in fp.
  (LOCAL_ADDRESS): New helper.
  (POP_CONTINUATION_HOOK): Reimplement, taking the previous FP as an
  argument.
  (ABORT_CONTINUATION_HOOK): Reimplement, taking no arguments.
  (RETURN_ONE_VALUE): Reimplement.
  (RETURN_VALUE_LIST): Adapt to FP change.
  (halt, return-values, subr-call, foreign-call, prompt)
  (continuation-call, compose-continuation, call/cc, abort): Adapt to FP
  change, mostly via using LOCAL_ADDRESS, etc abstractions instead of
  using the raw frame pointer.

* libguile/control.c (reify_partial_continuation): Update for fp
  change.

* libguile/vm.c (vm_reinstate_partial_continuation): Adapt to removal of
  SCM_FRAME_UPPER_ADDRESS.

* module/system/vm/frame.scm (frame-call-representation): Adapt to
  frame-local-ref change.

* module/system/vm/trace.scm (print-return): Remove unused
  frame-num-locals call.

1 files changed, 13 insertions, 13 deletions

diff --git a/libguile/frames.c b/libguile/frames.c
index 5ba600bd6..8ca628ae4 100644
--- a/libguile/frames.c
+++ b/libguile/frames.c
@@ -28,7 +28,7 @@
 
 /* Make sure assumptions on the layout of `struct scm_vm_frame' hold.  */
 verify (sizeof (SCM) == sizeof (SCM *));
-verify (sizeof (struct scm_vm_frame) == 4 * sizeof (SCM));
+verify (sizeof (struct scm_vm_frame) == 3 * sizeof (SCM));
 verify (offsetof (struct scm_vm_frame, dynamic_link) == 0);
 
 
@@ -115,14 +115,14 @@ SCM_DEFINE (scm_frame_num_locals, "frame-num-locals", 1, 0, 0,
 	    "")
 #define FUNC_NAME s_scm_frame_num_locals
 {
-  SCM *sp, *p;
+  SCM *fp, *sp;
 
   SCM_VALIDATE_VM_FRAME (1, frame);
 
+  fp = SCM_VM_FRAME_FP (frame);
   sp = SCM_VM_FRAME_SP (frame);
-  p = SCM_FRAME_STACK_ADDRESS (SCM_VM_FRAME_FP (frame));
 
-  return scm_from_ptrdiff_t (sp + 1 - p);
+  return scm_from_ptrdiff_t (SCM_FRAME_NUM_LOCALS (fp, sp));
 }
 #undef FUNC_NAME
 
@@ -131,17 +131,17 @@ SCM_DEFINE (scm_frame_local_ref, "frame-local-ref", 2, 0, 0,
 	    "")
 #define FUNC_NAME s_scm_frame_local_ref
 {
-  SCM *sp, *p;
+  SCM *fp, *sp;
   unsigned int i;
 
   SCM_VALIDATE_VM_FRAME (1, frame);
   SCM_VALIDATE_UINT_COPY (2, index, i);
 
+  fp = SCM_VM_FRAME_FP (frame);
   sp = SCM_VM_FRAME_SP (frame);
-  p = SCM_FRAME_STACK_ADDRESS (SCM_VM_FRAME_FP (frame));
 
-  if (p + i <= sp)
-    return SCM_FRAME_VARIABLE (SCM_VM_FRAME_FP (frame), i);
+  if (i < SCM_FRAME_NUM_LOCALS (fp, sp))
+    return SCM_FRAME_LOCAL (fp, i);
 
   SCM_OUT_OF_RANGE (SCM_ARG2, index);
 }
@@ -153,18 +153,18 @@ SCM_DEFINE (scm_frame_local_set_x, "frame-local-set!", 3, 0, 0,
 	    "")
 #define FUNC_NAME s_scm_frame_local_set_x
 {
-  SCM *sp, *p;
+  SCM *fp, *sp;
   unsigned int i;
 
   SCM_VALIDATE_VM_FRAME (1, frame);
   SCM_VALIDATE_UINT_COPY (2, index, i);
 
+  fp = SCM_VM_FRAME_FP (frame);
   sp = SCM_VM_FRAME_SP (frame);
-  p = SCM_FRAME_STACK_ADDRESS (SCM_VM_FRAME_FP (frame));
 
-  if (p + i <= sp)
+  if (i < SCM_FRAME_NUM_LOCALS (fp, sp))
     {
-      SCM_FRAME_VARIABLE (SCM_VM_FRAME_FP (frame), i) = val;
+      SCM_FRAME_LOCAL (fp, i) = val;
       return SCM_UNSPECIFIED;
     }
 
@@ -245,7 +245,7 @@ SCM_DEFINE (scm_frame_previous, "frame-previous", 1, 0, 0,
   if (new_fp) 
     {
       new_fp = RELOC (frame, new_fp);
-      new_sp = SCM_FRAME_LOWER_ADDRESS (this_fp) - 1;
+      new_sp = SCM_FRAME_PREVIOUS_SP (this_fp);
       frame = scm_c_make_frame (SCM_VM_FRAME_STACK_HOLDER (frame),
                                 new_fp, new_sp,
                                 SCM_FRAME_RETURN_ADDRESS (this_fp),