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43e01b1ee3
scm_catch_with_pre_unwind_handler, scm_with_throw_handler): New. * throw.c (SCM_JBPREUNWIND, SCM_SETJBPREUNWIND): New. (struct pre_unwind_data): New, replaces struct lazy_catch. (scm_c_catch): New, replaces scm_internal_catch as the primary catch API for C code; adds pre-unwind handler support. (scm_internal_catch): Now just a wrapper for scm_c_catch, for back compatibility. (tc16_pre_unwind_data, pre_unwind_data_print, make_pre_unwind_data, SCM_PRE_UNWIND_DATA_P): Renamed from "lazy_catch" equivalents. (scm_c_with_throw_handler): New, replaces scm_internal_lazy_catch as the primary C API for a "lazy" catch. (scm_internal_lazy_catch): Now just a wrapper for scm_c_with_throw_handler, for back compatibility. (scm_catch_with_pre_unwind_handler): Renamed from scm_catch; adds pre-unwind handler support. (scm_catch): Now just a wrapper for scm_catch_with_pre_unwind_handler, for back compatibility. (scm_with_throw_handler): New. (scm_lazy_catch): Update comment to say that the handler can return, and what happens if it does. (toggle_pre_unwind_running): New. (scm_ithrow): When identifying the throw target, take running flags into account. In general, change naming of things from "lazy_catch" to "pre_unwind". When throwing to a throw handler, don't unwind the dynamic context first. Add dynwind framing to manage the running flag of a throw handler. If a lazy catch or throw handler returns, rethrow the same exception again. Add pre-unwind support to the normal catch case (SCM_JMPBUFP). * root.c (scm_internal_cwdr): Add NULL args to scm_i_with_continuation_barrier call. * dynwind.c: Change comment mentioning lazy-catch to mention pre-unwind data and throw handler also. * continuations.h (scm_i_with_continuation_barrier): Add pre-unwind handler args. * continuations.c (scm_i_with_continuation_barrier): Add pre-unwind handler args, and pass on to scm_c_catch (changed from scm_internal_catch). (c_handler): Remove scm_handle_by_message_noexit call. (scm_c_with_continuation_barrier): Call scm_i_with_continuation_barrier with scm_handle_by_message_noexit as the pre-unwind handler. (scm_handler): Remove scm_handle_by_message_noexit call. (s_scm_with_continuation_barrier): Call scm_i_with_continuation_barrier with scm_handle_by_message_noexit as the pre-unwind handler.
110 lines
3.5 KiB
C
110 lines
3.5 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 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
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* License as published by the Free Software Foundation; either
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* version 2.1 of 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,
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* but 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 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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extern unsigned long * __libc_ia64_register_backing_store_base;
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#endif /* __ia64__ */
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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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SCM_API scm_t_bits scm_tc16_continuation;
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typedef struct
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{
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SCM throw_value;
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jmp_buf jmpbuf;
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SCM dynenv;
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#ifdef __ia64__
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ucontext_t ctx;
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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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/* 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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/* The most recently created debug frame on the live stack, before
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it was saved. This needs to be adjusted with OFFSET, above.
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*/
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struct scm_t_debug_frame *dframe;
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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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#define SCM_CONTINUATIONP(x) SCM_TYP16_PREDICATE (scm_tc16_continuation, x)
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#define SCM_CONTREGS(x) ((scm_t_contregs *) SCM_CELL_WORD_1 (x))
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#define SCM_CONTINUATION_LENGTH(x) (SCM_CONTREGS (x)->num_stack_items)
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#define SCM_SET_CONTINUATION_LENGTH(x, n)\
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(SCM_CONTREGS (x)->num_stack_items = (n))
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#define SCM_JMPBUF(x) ((SCM_CONTREGS (x))->jmpbuf)
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#define SCM_DYNENV(x) ((SCM_CONTREGS (x))->dynenv)
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#define SCM_THROW_VALUE(x) ((SCM_CONTREGS (x))->throw_value)
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#define SCM_CONTINUATION_ROOT(x) ((SCM_CONTREGS (x))->root)
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#define SCM_DFRAME(x) ((SCM_CONTREGS (x))->dframe)
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SCM_API SCM scm_make_continuation (int *first);
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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_API SCM 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_API 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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