Adapt VM stack to grow downward. This will make native compilation look
more like the VM code, as we will be able to use native CALL
instructions, taking proper advantage of the return address buffer.
* libguile/continuations.c (scm_i_continuation_to_frame): Record offsets
from stack top.
* libguile/control.c (scm_i_prompt_pop_abort_args_x): Adapt for reversed
order of arguments, and instead of relying on the abort to push on the
number of arguments, make the caller save the stack depth, which
allows us to compute the number of arguments ourselves.
(reify_partial_continuation, scm_c_abort): Adapt to reversed stack
order.
* libguile/dynstack.c (scm_dynstack_wind_prompt): Since we wind the
stack in a downward direction, subtract the reloc instead of adding
it.
* libguile/dynstack.h (SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY): Remove flag;
instead rely on prompt-establishing code to save the stack depth.
* libguile/eval.c (eval): Remove extraneous "volatile" declarations for
variables that are not re-set between the setjmp and any longjmp.
Adapt to save stack depth before instating the prompt.
* libguile/foreign.c (scm_i_foreign_call): Adapt to receive arguments in
reverse order.
* libguile/frames.c (frame_stack_top, scm_i_frame_stack_top): Adapt to
compute stack top instead of stack bottom.
(scm_c_frame_closure): Adapt to stack growth change.
(scm_frame_num_locals, scm_frame_local_ref, scm_frame_set_x): Use
union data type to access stack.
(RELOC): Reformat.
(scm_c_frame_previous): Adapt to stack growth change.
* libguile/frames.h: Adapt stack diagram to indicate that the stack
grows up.
(union scm_vm_stack_element): New data type used to access items on
the stack.
(SCM_FRAME_PREVIOUS_SP)
(SCM_FRAME_RETURN_ADDRESS, SCM_FRAME_SET_RETURN_ADDRESS)
(SCM_FRAME_DYNAMIC_LINK, SCM_FRAME_SET_DYNAMIC_LINK)
(SCM_FRAME_LOCAL, SCM_FRAME_NUM_LOCALS): Adapt to stack representation
change.
(SCM_FRAME_SLOT): New helper.
(SCM_VM_FRAME_FP, SCM_VM_FRAME_SP): Adapt to stack growth change.
* libguile/stacks.c (scm_make_stack): Record offsets from top of stack.
* libguile/throw.c (catch): Adapt to scm_i_prompt_pop_abort_args_x
change.
* libguile/vm-engine.c (ALLOC_FRAME, RESET_FRAME):
(FRAME_LOCALS_COUNT_FROM): Adapt to stack growth change.
(LOCAL_ADDRESS): Use SCM_FRAME_SLOT to get the address as the proper
data type.
(RETURN_ONE_VALUE, RETURN_VALUE_LIST): Adapt to stack growth change.
(apply): Shuffling up the SMOB apply args can cause the stack to
expand, so use ALLOC_FRAME instead of RESET_FRAME.
(vm_engine): Adapt for stack growth change.
* libguile/vm.c (vm_increase_sp, vm_push_sp, vm_restore_sp): Adapt to
stack representation change.
(scm_i_vm_cont_to_frame): Adapt to take offsets from the top.
(scm_i_vm_capture_stack): Adapt to capture from the top.
(vm_return_to_continuation_inner): Adapt for data type changes.
(vm_return_to_continuation): Likewise, and instead of looping, just
splat the saved arguments on with memcpy.
(vm_dispatch_hook): Adapt to receive arguments in the reverse order.
Adapt callers.
(vm_abort): There is never a tail argument. Adapt to stack
representation change.
(vm_reinstate_partial_continuation)
(vm_reinstate_partial_continuation_inner): Adapt to stack growth
change.
(allocate_stack, free_stack): Adapt to data type change.
(expand_stack): Don't try to mremap(), as you can't grow a mapping
from the bottom. Without knowing that there's a free mapping space
right below the old stack, which there usually isn't on Linux, we have
to copy. We can't use MAP_GROWSDOWN because Linux is buggy.
(make_vm): Adapt to stack representation changes.
(return_unused_stack_to_os): Round down instead of up, as the stack
grows down.
(scm_i_vm_mark_stack): Adapt to walk up the stack.
(scm_i_vm_free_stack): Adapt to scm_vm changes.
(vm_expand_stack_inner, reset_stack_limit, vm_expand_stack): Adapt to
the stack growing down.
(scm_call_n): Adapt to the stack growing down. Don't allow argv to
point into the stack.
* libguile/vm.h (struct scm_vm, struct scm_vm_cont): Adapt to hold the
stack top and bottom.
* libguile/dynstack.h:
* libguile/dynstack.c (PROMPT_FP, PROMPT_SP):
(scm_dynstack_push_prompt, scm_dynstack_find_prompt): Prompts on the
dynstack are recorded as offsets from the base stack address in this
thread.
* libguile/control.c (scm_c_abort):
* libguile/eval.c (eval):
* libguile/stacks.c (find_prompt, narrow_stack):
* libguile/throw.c (pre_init_catch):
* libguile/vm-engine.c (prompt): Adapt.
* libguile/frames.h (SCM_FRAME_RTL_RETURN_ADDRESS)
(SCM_FRAME_SET_RTL_RETURN_ADDRESS): Remove. The variants without _RTL
now work fine.
(struct scm_vm_frame): Change the return address to be a
scm_t_uint32*.
(struct scm_frame): Change IP to be scm_t_uint32*.
* libguile/frames.c (scm_c_make_frame)
* libguile/control.c (reify_partial_continuation, scm_c_abort)
* libguile/dynstack.c (PROMPT_IP)
(scm_dynstack_push_prompt, scm_dynstack_find_prompt)
* libguile/dynstack.h:
* libguile/vm-engine.c (SYNC_IP, RETURN_ONE_VALUE)
(call, return-values, prompt): Adapt.
* libguile/dynstack.h (SCM_DYNSTACK_TYPE_WITH_FLUID): Rename from
with-fluids.
* libguile/dynstack.c (scm_dynstack_push_fluid):
(scm_dynstack_unwind_fluid): Change API to only wind/unwind one
fluid binding.
(WITH_FLUID_WORDS): New define, always 2 words (fluid and value box).
(WITH_FLUID_FLUID, WITH_FLUID_VALUE_BOX): New macros to get offsets of
fluid and value box.
(scm_dynstack_push_rewinder, scm_dynstack_push_unwinder): Use
WINDER_WORDS.
(scm_dynstack_push_dynwind): Use DYNWIND_WORDS.
(scm_dynstack_wind_1): Update for scm_swap_fluid API change.
* libguile/fluids.h:
* libguile/fluids.c (scm_prepare_fluids): Remove; no longer needed.
(scm_swap_fluid): Update to just swap one fluid binding.
(scm_c_with_fluids, scm_c_with_fluid): Update to use
scm_dynstack_push_fluid.
* libguile/memoize.c (do_push_fluid, do_pop_fluid): Adapt to API
change.
* libguile/vm-engine.c (rtl_vm_engine): Change wind-fluids / unwind-fluids
to push-fluid / pop-fluid, and actually enable. Woo!
* libguile/vm-i-system.c (push-fluid, pop-fluid): Update to new API.
* libguile/control.h: Remove scm_t_prompt_registers and
scm_c_make_prompt_registers.
(scm_c_abort): Take a pointer to a jmpbuf instead of a cookie. It
will serve the same purpose.
* libguile/control.c (reify_partial_continuation, scm_at_abort): Adapt
to new prompt representation.
* libguile/dynstack.h:
* libguile/dynstack.c (scm_dynstack_push_prompt): Prompts now have 5
words instead of 2, as they now push the fp, sp, ip, and jmpbuf on the
stack separately. This avoids allocation.
(scm_dynstack_find_prompt): Likewise, add return values for fp, sp,
etc.
(scm_dynstack_wind_prompt): Replaces scm_dynstack_relocate_prompt.
* libguile/eval.c (eval):
* libguile/stacks.c (find_prompt):
* libguile/throw.c (pre_init_catch): Adapt to the new prompt mechanism.
* libguile/vm-engine.c (vm_engine): Setjmp an on-stack jmpbuf every time
the VM enters. We can then re-use that jmpbuf for all prompts in that
invocation.
* libguile/vm-i-system.c (partial_cont_call): Adapt to change in prompt
representation. We don't need to wind here any more, since we pass in
the prompt's jmpbuf.
(prompt): Adapt to scm_dynstack_push_prompt change.
(abort): Adapt to vm_abort change.
* libguile/vm.h (struct scm_vm): No more cookie.
* libguile/vm.c (vm_abort): Adapt to scm_c_abort change.
(vm_reinstate_partial_continuation): Rewind the dynamic stack here,
now that we do have a valid jmpbuf.
(make_vm): No need to initialize a cookie.
* libguile/dynstack.h:
* libguile/dynstack.c: New files, implementing the dynamic stack as a
true stack instead of a linked list. This lowers the cost of
dynwinds: frames, winders, prompts, with-fluids, and dynamic-wind.
For the most part, we allocate these items directly on the stack.
* libguile/dynwinds.h:
* libguile/dynwinds.c: Adapt all manipulators of the wind stack to use
interfaces from dynstack.c. Remove heap-allocated winder and frame
object types.
(scm_dowinds, scm_i_dowinds): Remove these. The first was exported,
but it was not a public interface.
* libguile/continuations.c:
* libguile/continuations.h (scm_t_contregs): Continuation objects
reference scm_t_dynstack* values now. Adapt to the new interfaces.
* libguile/control.c:
* libguile/control.h: There is no longer a scm_tc7_prompt kind of object
that can be allocated on the heap. Instead, the prompt flags, key,
and registers are pushed on the dynwind stack. (The registers are
still on the heap.) Also, since the vm_cont will reference the
dynwinds, make the partial continuation stub take just one extra arg,
instead of storing the intwinds separately in the object table.
* libguile/fluids.c:
* libguile/fluids.h: No more with-fluids objects; instead, the fluids go
on the dynstack. The values still have to be on the heap, though.
(scm_prepare_fluids, scm_swap_fluids): New internal functions,
replacing scm_i_make_with_fluids and scm_i_swap_with_fluids.
* libguile/print.c: Remove prompt and with-fluids printers.
* libguile/tags.h: Revert prompt and with-fluids tc7 values to what they
were before they were allocated.
* libguile/vm-i-system.c (partial_cont_call): Just pop the vmcont, the
intwinds will not be passed as a second arg. Rewind the dynamic stack
from within the VM, so that any rewinder sees valid prompt entries.
(call_cc, tail_call_cc): Adapt to pass the dynstack to
scm_i_vm_capture_stack.
(prompt, wind, unwind, wind_fluids, unwind_fluids): Adapt to the new
interfaces.
* libguile/vm.h (scm_i_capture_current_stack): Rename from
scm_i_vm_capture_continuation.
(scm_i_vm_capture_stack): Take a dynstack as an argument.
* libguile/vm.c (vm_reinstate_partial_continuation): Don't wind here, as
that could result in winders seeing invalid prompts.
* libguile/eval.c:
* libguile/root.c:
* libguile/stacks.c:
* libguile/threads.c:
* libguile/threads.h:
* libguile/throw.c: Adapt other users of dynwinds to use the dynstack.
