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author | Andy Wingo <wingo@pobox.com> | 2013-10-18 18:44:11 +0200 |
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committer | Andy Wingo <wingo@pobox.com> | 2013-10-18 18:47:49 +0200 |
commit | d691ac206906d2539cb94667fd10854aafc8955a (patch) | |
tree | d8ab6e05a3bd9971fb25a0e4e9998209ffd08ced /libguile/continuations.c | |
parent | 8bd261baaa96eba005517eef5fb8d5d08f22720a (diff) | |
download | guile-d691ac206906d2539cb94667fd10854aafc8955a.tar.gz |
Continuations are RTL stubs
* libguile/continuations.h:
* libguile/continuations.c: Reimplement continuations and the call_cc
stub as RTL programs.
* libguile/programs.c (scm_i_rtl_program_minimum_arity): Add a case for
continuations.
* libguile/vm-engine.c (rtl_vm_debug_engine): Always call the abort
continuation hook with the number of non-procedure locals. Fix
compose-continuation argument count. Enable call/cc.
Diffstat (limited to 'libguile/continuations.c')
-rw-r--r-- | libguile/continuations.c | 120 |
1 files changed, 24 insertions, 96 deletions
diff --git a/libguile/continuations.c b/libguile/continuations.c index fe7618f5e..58a193618 100644 --- a/libguile/continuations.c +++ b/libguile/continuations.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1995,1996,1998,2000,2001,2004, 2006, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc. +/* Copyright (C) 1995,1996,1998,2000,2001,2004, 2006, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License @@ -58,107 +58,35 @@ static scm_t_bits tc16_continuation; -/* scm_i_make_continuation will return a procedure whose objcode contains an - instruction to reinstate the continuation. Here, as in gsubr.c and smob.c, we - define the form of that trampoline function. +/* scm_i_make_continuation will return a procedure whose code will + reinstate the continuation. Here, as in gsubr.c, we define the form + of that trampoline function. */ -#ifdef WORDS_BIGENDIAN -#define OBJCODE_HEADER(main,meta) 0, 0, 0, main, 0, 0, 0, meta+8 -#define META_HEADER(meta) 0, 0, 0, meta, 0, 0, 0, 0 -#else -#define OBJCODE_HEADER(main,meta) main, 0, 0, 0, meta+8, 0, 0, 0 -#define META_HEADER(meta) meta, 0, 0, 0, 0, 0, 0, 0 -#endif - -#define OBJCODE_TAG SCM_MAKE_OBJCODE_TAG (SCM_OBJCODE_TYPE_STATIC, 0) - -#if defined (SCM_ALIGNED) && 0 -#define SCM_DECLARE_STATIC_ALIGNED_ARRAY(type, sym) \ -static const type sym[] -#define SCM_STATIC_ALIGNED_ARRAY(alignment, type, sym) \ -static SCM_ALIGNED (alignment) const type sym[] -#define SCM_STATIC_OBJCODE(sym) \ - SCM_DECLARE_STATIC_ALIGNED_ARRAY (scm_t_uint8, sym##__bytecode); \ - SCM_STATIC_ALIGNED_ARRAY (8, scm_t_cell, sym##__cells) = { \ - { SCM_PACK (OBJCODE_TAG), SCM_PACK (sym##__bytecode) }, \ - { SCM_BOOL_F, SCM_PACK (0) } \ - }; \ - static const SCM sym = SCM_PACK (sym##__cells); \ - SCM_STATIC_ALIGNED_ARRAY (8, scm_t_uint8, sym##__bytecode) -#else -#define SCM_STATIC_OBJCODE(sym) \ -static SCM sym; \ -static scm_t_uint8 *sym##_bytecode; \ -SCM_SNARF_INIT(sym##_bytecode = scm_gc_malloc_pointerless (sizeof(sym##_bytecode__unaligned), "partial continuation stub"); \ - memcpy (sym##_bytecode, sym##_bytecode__unaligned, sizeof(sym##_bytecode__unaligned));) \ -SCM_SNARF_INIT(sym = scm_double_cell (OBJCODE_TAG, \ - (scm_t_bits)sym##_bytecode, \ - SCM_UNPACK (SCM_BOOL_F), \ - 0);) \ -static const scm_t_uint8 sym##_bytecode__unaligned[] -#endif +static const scm_t_uint32 continuation_stub_code[] = + { + SCM_PACK_RTL_24 (scm_rtl_op_continuation_call, 0) + }; +/* Before Scheme's call/cc is compiled, eval.c will use this hand-coded + call/cc. */ -SCM_STATIC_OBJCODE (cont_objcode) = { - /* This code is the same as in gsubr.c, except we use continuation_call - instead of subr_call. */ - OBJCODE_HEADER (8, 19), - /* leave args on the stack */ - /* 0 */ scm_op_object_ref, 0, /* push scm_t_contregs smob */ - /* 2 */ scm_op_continuation_call, /* and longjmp (whee) */ - /* 3 */ scm_op_nop, /* pad to 8 bytes */ - /* 4 */ scm_op_nop, scm_op_nop, scm_op_nop, scm_op_nop, - /* 8 */ - - /* We could put some meta-info to say that this proc is a continuation. Not sure - how to do that, though. */ - META_HEADER (19), - /* 0 */ scm_op_make_eol, /* bindings */ - /* 1 */ scm_op_make_eol, /* sources */ - /* 2 */ scm_op_make_int8, 0, scm_op_make_int8, 3, /* arity: from ip 0 to ip 3 */ - /* 6 */ scm_op_make_int8_0, /* the arity is 0 required args */ - /* 7 */ scm_op_make_int8_0, /* 0 optionals */ - /* 8 */ scm_op_make_true, /* and a rest arg */ - /* 9 */ scm_op_list, 0, 5, /* make a list of those 5 vals */ - /* 12 */ scm_op_list, 0, 1, /* and the arities will be a list of that one list */ - /* 15 */ scm_op_list, 0, 3, /* pack bindings, sources, and arities into list */ - /* 18 */ scm_op_return /* and return */ - /* 19 */ -}; - - -SCM_STATIC_OBJCODE (call_cc_objcode) = { - /* Before Scheme's call/cc is compiled, eval.c will use this hand-coded - call/cc. */ - OBJCODE_HEADER (8, 17), - /* 0 */ scm_op_assert_nargs_ee, 0, 1, /* assert that nargs==1 */ - /* 3 */ scm_op_local_ref, 0, /* push the proc */ - /* 5 */ scm_op_tail_call_cc, /* and call/cc */ - /* 6 */ scm_op_nop, scm_op_nop, /* pad to 8 bytes */ - /* 8 */ - - META_HEADER (17), - /* 0 */ scm_op_make_eol, /* bindings */ - /* 1 */ scm_op_make_eol, /* sources */ - /* 2 */ scm_op_make_int8, 3, scm_op_make_int8, 6, /* arity: from ip 0 to ip 6 */ - /* 6 */ scm_op_make_int8_1, /* the arity is 0 required args */ - /* 7 */ scm_op_list, 0, 3, /* make a list of those 5 vals */ - /* 10 */ scm_op_list, 0, 1, /* and the arities will be a list of that one list */ - /* 13 */ scm_op_list, 0, 3, /* pack bindings, sources, and arities into list */ - /* 16 */ scm_op_return /* and return */ - /* 17 */ -}; - +static const scm_t_uint32 call_cc_code[] = + { + SCM_PACK_RTL_24 (scm_rtl_op_assert_nargs_ee, 2), + SCM_PACK_RTL_24 (scm_rtl_op_call_cc, 0) + }; static SCM make_continuation_trampoline (SCM contregs) { - SCM ret = scm_make_program (cont_objcode, - scm_c_make_vector (1, contregs), - SCM_BOOL_F); - SCM_SET_CELL_WORD_0 (ret, - SCM_CELL_WORD_0 (ret) | SCM_F_PROGRAM_IS_CONTINUATION); + SCM ret; + scm_t_bits nfree = 1; + scm_t_bits flags = SCM_F_PROGRAM_IS_CONTINUATION; + + ret = scm_words (scm_tc7_rtl_program | (nfree << 16) | flags, nfree + 2); + SCM_SET_CELL_WORD_1 (ret, continuation_stub_code); + SCM_RTL_PROGRAM_FREE_VARIABLE_SET (ret, 0, contregs); return ret; } @@ -252,7 +180,7 @@ scm_i_call_with_current_continuation (SCM proc) static SCM call_cc = SCM_BOOL_F; if (scm_is_false (call_cc)) - call_cc = scm_make_program (call_cc_objcode, SCM_BOOL_F, SCM_BOOL_F); + call_cc = scm_i_make_rtl_program (call_cc_code); return scm_call_1 (call_cc, proc); } @@ -263,7 +191,7 @@ scm_i_continuation_to_frame (SCM continuation) SCM contregs; scm_t_contregs *cont; - contregs = scm_c_vector_ref (scm_program_objects (continuation), 0); + contregs = SCM_RTL_PROGRAM_FREE_VARIABLE_REF (continuation, 0); cont = SCM_CONTREGS (contregs); if (scm_is_true (cont->vm_cont)) |