/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@vu.nl WWW: www.swi-prolog.org Copyright (c) 2008-2020, University of Amsterdam VU University Amsterdam All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ :- module(prolog_vm, [ vm_list/1, % :Spec clause_vm/2, % +ClauseRef,-VM:list vmi_labels/2 % ?VMI,?Labeled ]). :- autoload(library(lists),[member/2]). :- autoload(library(prolog_clause),[predicate_name/2]). /** SWI-Prolog Virtual Machine utilities This is an internal developers module to manage the virtual machine instructions. */ :- meta_predicate vm_list(:). %! vm_list(:Spec) is det. % % Lists the definition of the predicates matching Spec to % =current_output=. Spec is also allowed to be a clause-reference. vm_list(_:Ref) :- blob(Ref, clause), !, ( nth_clause(_Head, N, Ref), format('~40c~nclause ~d (~w):~n~40c~n', [0'-, N, Ref, 0'-]), vm_list_clause(Ref), fail ; true ). vm_list(Spec) :- '$find_predicate'(Spec, List), ( member(PI, List), pi_to_head(PI, Head), unify_args(Head, Spec), predicate_name(Head, Name), format('~72c~n~w~n~72c~n', [0'=, Name, 0'=]), ( '$fetch_vm'(Head, 0, _, _) -> vm_list_clause(Head) ; format(' (No supervisor)~n') ), ( nth_clause(Head, N, Ref), clause(MHead, _, Ref), same_head(Head, MHead), format('~40c~nclause ~d (~w):~n~40c~n', [0'-, N, Ref, 0'-]), vm_list_clause(Ref), fail ; true ), fail ; true ). pi_to_head(M:PI, M:Head) :- !, pi_to_head(PI, Head). pi_to_head(Name/Arity, Head) :- functor(Head, Name, Arity). vm_list_clause(Clause) :- clause_vm(Clause, VM), vmi_labels(VM, Labeled), vm_list_labeled(Labeled, 0). vm_list_labeled([], _). vm_list_labeled([label(L),vmi(break(VMI),Size)|T], PC) :- !, format('~w: ~t~d~8| ~q % ~n', [L, PC, VMI]), PC1 is PC+Size, vm_list_labeled(T, PC1). vm_list_labeled([label(L),vmi(VMI,Size)|T], PC) :- format('~w: ~t~d~8| ~q~n', [L, PC, VMI]), PC1 is PC+Size, vm_list_labeled(T, PC1). vm_list_labeled([vmi(break(VMI),Size)|T], PC) :- !, format('~t~d~8| ~q % ~n', [PC, VMI]), PC1 is PC+Size, vm_list_labeled(T, PC1). vm_list_labeled([vmi(VMI,Size)|T], PC) :- format('~t~d~8| ~q~n', [PC, VMI]), PC1 is PC+Size, vm_list_labeled(T, PC1). % Unify the arguments of the specification with the given term, % so we can partially instantate the head. unify_args(_, _/_) :- !. % Name/arity spec unify_args(X, X) :- !. unify_args(_:X, X) :- !. unify_args(_, _). same_head(X, X) :- !. same_head(H1, H2) :- strip_module(H1, _, H), strip_module(H2, _, H). %! clause_vm(+ClauseRef, -VM:list) is det. % % True when VM is the virtual machine code of ClauseRef. Each % instruction is a term vmi(VMI,Size). clause_vm(Ref, VM) :- clause_vm(Ref, 0, VM). clause_vm(Clause, PC, [vmi(VMI,Size)|T]) :- '$fetch_vm'(Clause, PC, NextPC, VMI), !, Size is NextPC-PC, clause_vm(Clause, NextPC, T). clause_vm(_, _, []). %! vmi_labels(?VMI, ?Labeled) % % Translated between a raw and a labeled representation for a VMI % sequence as produced by clause_vm/2. Assumes we only jump % _forwards_. % % In the labeled represention the `jump` arguments of VMIs are label % names and there are entries label(Name) in the list. vmi_labels(VMI, Labeled) :- nonvar(VMI), !, label_vmi(VMI, 0, 0, [], Labeled). vmi_labels(VMI, Labeled) :- unlabel_vmi(Labeled, 0, [], VMI). % Raw --> Labeled label_vmi([], _, _, _, []). label_vmi([H|T], Here0, LI0, Pending0, Labeled) :- H = vmi(VMI0,Size), Here is Here0+Size, new_labels(VMI0, VMI, LI0, LI1, Here0, Here, Pending0, Pending1), ( selectchk(Label-Here0, Pending1, Pending2) -> Labeled = [label(Label),vmi(VMI,Size)|Labeled1] ; Labeled = [vmi(VMI,Size)|Labeled1], Pending2 = Pending1 ), label_vmi(T, Here, LI1, Pending2, Labeled1). new_labels(break(VMI0), break(VMI), LI0, LI, Start, End, Labels0, Labels) :- !, new_labels(VMI0, VMI, LI0, LI, Start, End, Labels0, Labels). new_labels(VMI0, VMI, LI0, LI, Start, End, Labels0, Labels) :- VMI0 =.. [Name|Argv0], '$vmi_property'(Name, argv(ArgvTypes)), jmp_rel(Name, Start, End, Rel), new_labels_(ArgvTypes, Argv0, Argv, LI0, LI, Rel, Labels0, Labels), VMI =.. [Name|Argv]. %! jmp_rel(+VMIName, +Start, +End, -JmpRel) % % Relative position for the (choice) jump. This is the end of the % instruction for most, but after the address for the compiled trie % instructions. Should be made consistent. jmp_rel(TrieVMI, Start, _End, Rel) :- trie_vmi(TrieVMI), !, Rel is Start+2. jmp_rel(_, _, End, End). trie_vmi(VMI) :- sub_atom(VMI, 0, _, _, t_). new_labels_([], [], [], LI, LI, _, Labels, Labels). new_labels_([jump|TT], [Offset|AT], [Label|LT], LI0, LI, End, Labels0, Labels) :- !, To is End+Offset, ( memberchk(Label-To, Labels0) -> Labels1 = Labels0, LI1 = LI0 ; LI1 is LI0+1, atom_concat('L', LI1, Label), Labels1 = [Label-To|Labels0] ), new_labels_(TT, AT, LT, LI1, LI, End, Labels1, Labels). new_labels_([_|TT], [A|AT], [A|LT], LI0, LI, End, Labels0, Labels) :- new_labels_(TT, AT, LT, LI0, LI, End, Labels0, Labels). % Labeled --> Raw unlabel_vmi([], _, _, []). unlabel_vmi([label(L)|T0], Here, Labels0, T) :- !, resolve_labels(L, Here, Labels0, Labels), unlabel_vmi(T0, Here, Labels, T). unlabel_vmi([vmi(VMI0,Size)|T0], Here0, Labels0, [vmi(VMI,Size)|T]) :- Here is Here0+Size, get_labels(VMI0, VMI, Here, Labels0, Labels), unlabel_vmi(T0, Here, Labels, T). get_labels(VMI0, VMI, Here, Labels0, Labels) :- VMI0 =.. [Name|Argv0], '$vmi_property'(Name, argv(ArgvTypes)), get_labels_(ArgvTypes, Argv0, Argv, Here, Labels0, Labels), VMI =.. [Name|Argv]. get_labels_([], [], [], _, Labels, Labels). get_labels_([jump|TT], [Label|LT], [Offset|AT], Here, Labels0, [l(Label,Here,Offset)|Labels]) :- !, get_labels_(TT, LT, AT, Here, Labels0, Labels). get_labels_([_|TT], [A|LT], [A|AT], Here, Labels0, Labels) :- get_labels_(TT, LT, AT, Here, Labels0, Labels). resolve_labels(L, Here, Labels0, Labels) :- selectchk(l(L,End,Offset), Labels0, Labels1), !, Offset is Here-End, resolve_labels(L, Here, Labels1, Labels). resolve_labels(_, _, Labels, Labels).