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d8873dfe47
* libguile/vm.h (struct scm_vm_cont): Instead of saving the "IP", save "RA" and "MVRA". That is, save singly-valued and multiply-valued return addresses, so that we can return multiple values on the stack. (scm_i_vm_reinstate_continuation): Remove. * libguile/vm.c (vm_capture_continuation): Rename from capture_vm_cont, and change the prototype so we can capture the RA and MVRA, and so that tail calls to call/cc can capture a continuation without the call/cc application frame. (vm_return_to_continuation): Rename from reinstate_vm_cont, and take arguments to return to the continuation. Handles returning to single or multiple-value RA. (scm_i_vm_capture_continuation): Change to invoke vm_capture_continuation. Kept around for the benefit of make-stack. * libguile/vm-i-system.c (continuation-call): Handle reinstatement of the VM stack, with arguments. (call/cc, tail-call/cc): Adapt to new vm_capture_continuation prototype. tail-call/cc captures tail continuations. * libguile/stacks.c (scm_make_stack): Update for scm_vm_cont structure change. * libguile/continuations.h (struct scm_contregs): Remove throw_value member, which was used to return a value to a continuation. (scm_i_check_continuation): New internal function, checks that a continuation may be reinstated. (scm_i_reinstate_continuation): Replaces scm_i_continuation_call; just reinstates the C stack. (scm_i_contregs_vm, scm_i_contregs_vm_cont): New internal accessors. * libguile/continuations.c (scm_i_make_continuation): Return SCM_UNDEFINED if we are returning again. (grow_stack, copy_stack_and_call, scm_dynthrow): Remove extra arg, as vm opcodes handle value returns. (copy_stack): No need to instate VM continuation. (scm_i_reinstate_continuation): Adapt.
103 lines
3.1 KiB
C
103 lines
3.1 KiB
C
/* classes: h_files */
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#ifndef SCM_CONTINUATIONS_H
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#define SCM_CONTINUATIONS_H
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/* Copyright (C) 1995,1996,2000,2001, 2006, 2008, 2009, 2010 Free Software Foundation, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either version 3 of
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* the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#include "libguile/__scm.h"
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#ifdef __ia64__
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#include <signal.h>
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#include <ucontext.h>
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#endif /* __ia64__ */
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#define SCM_CONTINUATIONP(x) \
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(SCM_PROGRAM_P (x) && SCM_PROGRAM_IS_CONTINUATION (x))
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/* a continuation SCM is a non-immediate pointing to a heap cell with:
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word 0: bits 0-15: smob type tag: scm_tc16_continuation.
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bits 16-31: unused.
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word 1: malloc block containing an scm_t_contregs structure with a
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tail array of SCM_STACKITEM. the size of the array is stored
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in the num_stack_items field of the structure.
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*/
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typedef struct
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{
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scm_i_jmp_buf jmpbuf;
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SCM dynenv;
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#ifdef __ia64__
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void *backing_store;
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unsigned long backing_store_size;
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#endif /* __ia64__ */
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size_t num_stack_items; /* size of the saved stack. */
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SCM root; /* continuation root identifier. */
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SCM vm; /* vm */
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SCM vm_cont; /* vm's stack and regs */
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/* The offset from the live stack location to this copy. This is
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used to adjust pointers from within the copied stack to the stack
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itself.
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Thus, when you read a pointer from the copied stack that points
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into the live stack, you need to add OFFSET so that it points
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into the copy.
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*/
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scm_t_ptrdiff offset;
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SCM_STACKITEM stack[1]; /* copied stack of size num_stack_items. */
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} scm_t_contregs;
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SCM_INTERNAL SCM scm_i_make_continuation (int *first, SCM vm, SCM vm_cont);
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SCM_INTERNAL void scm_i_check_continuation (SCM cont);
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SCM_INTERNAL void scm_i_reinstate_continuation (SCM cont);
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SCM_INTERNAL SCM scm_i_call_with_current_continuation (SCM proc);
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SCM_INTERNAL SCM scm_i_continuation_to_frame (SCM cont);
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SCM_INTERNAL SCM scm_i_contregs_vm (SCM contregs);
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SCM_INTERNAL SCM scm_i_contregs_vm_cont (SCM contregs);
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SCM_API void *scm_c_with_continuation_barrier (void *(*func)(void*), void *);
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SCM_API SCM scm_with_continuation_barrier (SCM proc);
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SCM_INTERNAL SCM
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scm_i_with_continuation_barrier (scm_t_catch_body body,
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void *body_data,
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scm_t_catch_handler handler,
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void *handler_data,
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scm_t_catch_handler pre_unwind_handler,
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void *pre_unwind_handler_data);
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SCM_INTERNAL void scm_init_continuations (void);
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#endif /* SCM_CONTINUATIONS_H */
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/*
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Local Variables:
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c-file-style: "gnu"
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End:
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*/
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