1/*  Part of SWISH
    2
    3    Author:        Jan Wielemaker
    4    E-mail:        J.Wielemaker@vu.nl
    5    WWW:           http://www.swi-prolog.org
    6    Copyright (c)  2015-2017, VU University Amsterdam
    7    All rights reserved.
    8
    9    Redistribution and use in source and binary forms, with or without
   10    modification, are permitted provided that the following conditions
   11    are met:
   12
   13    1. Redistributions of source code must retain the above copyright
   14       notice, this list of conditions and the following disclaimer.
   15
   16    2. Redistributions in binary form must reproduce the above copyright
   17       notice, this list of conditions and the following disclaimer in
   18       the documentation and/or other materials provided with the
   19       distribution.
   20
   21    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   25    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   29    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   31    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   32    POSSIBILITY OF SUCH DAMAGE.
   33*/
   34
   35:- module(swish_include,
   36          [ include/2                          % +File, +Options
   37          ]).   38:- use_module(storage).   39:- use_module(config).   40:- use_module(library(sandbox), []).   41:- use_module(library(debug)).   42:- use_module(library(option)).   43:- use_module(library(filesex)).   44:- use_module(library(error)).   45:- use_module(library(readutil)).   46
   47/** <module> Support :- include(File) from SWISH
   48
   49This module allows SWISH programs  to   include  other programs from the
   50shared gitty store. It realises this using the following steps:
   51
   52  - Use term_expansion/2 to rewrite the include to fetch the data from
   53    the gitty store.
   54  - Declare this specific version of include safe.
   55  - Adjust the colourization to indicate the shared file as existing.
   56  - Hook the Prolog cross-referencer to process the included file.
   57
   58We allow for hierarchical and circular includes.
   59*/
   60
   61%!  include(+File, +Options)
   62%
   63%   Include file at a specific version.  Supported options:
   64%
   65%     - version(Version)
   66%     Include version Version of File, where Version is a gitty
   67%     commit of the file.  This is the same as `:- include(Version).`,
   68%     but more explicit.
   69%
   70%   If the same file is included at two places it is included at most
   71%   once.  Additionally
   72%
   73%     - If neither is versioned the most recent version is included.
   74%     - If two versions resolve to the same content hash, this is
   75%       included.
   76%     - If a specific version is included, subsequent unspecified
   77%       includes are ignored.  A subsequent incompatibly versioned
   78%       include results in an error.
   79%
   80%   The envisioned model is that we can specify which version is,
   81%   possibly indirectly, included by using directives like this:
   82%
   83%     ==
   84%     :- include(File, [version(Hash)]).
   85%     ==
   86
   87include(File, Version) :-
   88    throw(error(context_error(nodirective, include(File, Version)), _)).
   89
   90swish:term_expansion(:- include(FileIn), Expansion) :-
   91    swish:term_expansion(:- include(FileIn, []), Expansion).
   92swish:term_expansion(:- include(FileIn, Options), Expansion) :-
   93    setup_call_cleanup(
   94        '$push_input_context'(swish_include),
   95        expand_include(FileIn, Options, Expansion),
   96        '$pop_input_context').
   97
   98expand_include(FileIn, Options, Expansion) :-
   99    include_file_id(FileIn, File, Options),
  100    arg(2, File, IncludeID),
  101    (   prolog_load_context(module, Module),
  102        clause(Module:'swish included'(IncludeID), true)
  103    ->  Expansion = []
  104    ;   Expansion = [ (:- discontiguous('swish included'/1)),
  105                      'swish included'(IncludeID),
  106                      (:- include(stream(URI, Stream, [close(true)])))
  107                    ],
  108        include_data(File, URI, Data),
  109        open_string(Data, Stream)
  110    ).
  111
  112%!  include_data(+FileID, -URI, -Data)
  113%
  114%   Fetch the data to be included and obtain the URI for it.
  115
  116include_data(file(Name, _Data, gitty(Meta)), URI, Data) :-
  117    !,
  118    catch(storage_file(Meta.commit, Data, _Meta),
  119          error(existence_error(_,_),_),
  120          fail),
  121    atom_concat('swish://', Name, URI).
  122include_data(file(Spec, Spec, filesystem), URI, Data) :-
  123    absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  124    read_file_to_string(Path, Data, []),
  125    Spec =.. [Alias,_],
  126    file_base_name(Path, NameExt),
  127    format(atom(URI), 'swish://~w/~w', [Alias, NameExt]).
  128
  129
  130%!  include_file_id(+FileIn, -FileID, +Options) is det.
  131%
  132%   Normalise an include file identifier and verify its safeness.
  133
  134include_file_id(FileIn, file(File, IncludeID, gitty(Meta)), Options) :-
  135    atomic(FileIn),
  136    !,
  137    atom_string(File0, FileIn),
  138    add_extension(File0, File),
  139    (   option(version(Version), Options)
  140    ->  storage_meta_data(Version, Meta)
  141    ;   storage_meta_data(File, Meta)
  142    ),
  143    atom_concat('swish://', Meta.name, URI),
  144    IncludeID0 = gitty(Meta.commit, Meta.data, URI),
  145    (   prolog_load_context(module, Module),
  146        clause(Module:'swish included'(IncludeIDPrev), true),
  147        compatible_versions(IncludeIDPrev, IncludeID0, Version)
  148    ->  IncludeID = IncludeIDPrev
  149    ;   IncludeID = IncludeID0
  150    ).
  151include_file_id(FileIn, file(File, File, filesystem), _) :-
  152    compound(FileIn),
  153    FileIn =.. [Alias,NameIn],
  154    atom_string(Name, NameIn),
  155    (   safe_name(Name),
  156        swish_config(include_alias, Alias)
  157    ->  true
  158    ;   permission_error(include, file, Name)
  159    ),
  160    File =.. [Alias,Name].
  161
  162compatible_versions(Version, Version, _) :- !.
  163compatible_versions(gitty(_, DataHash, _), gitty(_, DataHash, _), _) :- !.
  164compatible_versions(Gitty1, Gitty2, Version) :- !,
  165    Gitty1 = gitty(_, _, URI),
  166    Gitty2 = gitty(_, _, URI),
  167    (   var(Version)
  168    ->  true
  169    ;   throw(error(version_error(Gitty1, Gitty2), _))
  170    ).
  171
  172safe_name(Name) :-
  173    \+ (   sub_atom(Name, 0, _, _, '../')
  174       ;   sub_atom(Name, _, _, _, '/../')
  175       ;   sub_atom(Name, _, _, 0, '/..')
  176       ;   Name == '..'
  177       ).
  178
  179%!  file_alias(+File, -Spec) is semidet.
  180%
  181%   Translate Alias/Name into Alias(Name) if Alias  is known and Name is
  182%   safe.
  183
  184file_alias(File, Spec) :-
  185    atomic_list_concat([Alias,Name], /, File),
  186    swish_config(include_alias, Alias),
  187    safe_name(Name),
  188    !,
  189    Spec =.. [Alias,Name].
  190
  191%!  add_extension(+File, -FileExt) is det.
  192%
  193%   Add a file name extension to indicate this is a Prolog file.
  194
  195add_extension(File, FileExt) :-
  196    file_name_extension(_, Ext, File),
  197    Ext \== '',
  198    !,
  199    FileExt = File.
  200add_extension(Hash, Hash) :-
  201    is_hash(Hash),
  202    !.
  203add_extension(File, FileExt) :-
  204    file_name_extension(File, pl, FileExt).
  205
  206is_hash(Name) :-
  207    atom_length(Name, 40),
  208    split_string(Name, ":", "0123456789abcdef", [""]).
  209
  210
  211                 /*******************************
  212                 *            SANDBOX           *
  213                 *******************************/
  214
  215:- multifile
  216    sandbox:safe_directive/1.  217
  218sandbox:safe_directive(M:include(stream(Id, Stream, [close(true)]))) :-
  219    is_stream(Stream),
  220    sub_atom(Id, 0, _, _, 'swish://'),
  221    prolog_load_context(module, M).
  222
  223
  224                 /*******************************
  225                 *            COLOUR            *
  226                 *******************************/
  227
  228:- multifile
  229    prolog_colour:term_colours/2.  230
  231prolog_colour:term_colours((:- include(FileIn, Options)),
  232                           neck(directive) -
  233                           [ goal(built_in,include(FileIn)) -
  234                             [ FileClass,
  235                               classify
  236                             ]
  237                           ]) :-
  238    classify_include(FileIn, FileClass, Options).
  239prolog_colour:term_colours((:- include(FileIn)),
  240                           neck(directive) -
  241                           [ goal(built_in,include(FileIn)) -
  242                             [ FileClass
  243                             ]
  244                           ]) :-
  245    classify_include(FileIn, FileClass, []).
  246
  247classify_include(FileIn, FileClass, Options) :-
  248    debug(include, 'Classifying ~p', [FileIn]),
  249    (   catch(include_file_id(FileIn, FileID, Options), _, fail)
  250    ->  classify_include(FileID, FileClass)
  251    ;   FileClass = nofile
  252    ),
  253    debug(include, 'Class ~p', [FileClass]).
  254
  255classify_include(file(Name, _DataHash, gitty(Meta)), FileClass) :-
  256    !,
  257    (   is_hash(Name)
  258    ->  format(atom(Id), 'swish://~w@~w', [Meta.name, Name])
  259    ;   atom_concat('swish://', Name, Id)
  260    ),
  261    FileClass = file(Id).
  262classify_include(file(Spec, Spec, filesystem), FileClass) :-
  263    absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  264    Spec =.. [Alias,_],
  265    file_base_name(Path, NameExt),
  266    format(atom(URI), 'swish://~w/~w', [Alias, NameExt]),
  267    FileClass = file(URI).
  268
  269
  270                 /*******************************
  271                 *            XREF              *
  272                 *******************************/
  273
  274:- multifile
  275    prolog:xref_open_source/2,
  276    prolog:xref_source_file/3,
  277    prolog:xref_source_identifier/2,
  278    prolog:xref_source_time/2.  279
  280%!  prolog:xref_source_identifier(+Src, -Id) is semidet.
  281%!  prolog:xref_open_source(+File, -Stream) is det.
  282%!  prolog:xref_source_time(+File, -Modified) is det.
  283%
  284%   Map swish://file to a file from the gitty store.
  285
  286prolog:xref_source_identifier(Src, Id) :-
  287    atom(Src),
  288    sub_atom(Src, 0, _, _, 'swish://'),
  289    !,
  290    Id = Src.
  291
  292prolog:xref_open_source(File, Stream) :-
  293    atom(File),
  294    atom_concat('swish://', Name, File),
  295    (   file_alias(File, Spec)
  296    ->  absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  297        open(Path, read, Stream)
  298    ;   catch(storage_file(Name, Data, _Meta), _, fail),
  299        open_string(Data, Stream)
  300    ).
  301
  302prolog:xref_source_time(File, Modified) :-
  303    atom(File),
  304    atom_concat('swish://', Name, File),
  305    (   file_alias(File, Spec)
  306    ->  absolute_file_name(Spec, Path, [ file_type(prolog), access(read) ]),
  307        time_file(Path, Modified)
  308    ;   catch(storage_meta_data(Name, Meta), _, fail),
  309        Modified = Meta.get(time)
  310    ).
  311
  312%!  prolog:xref_source_file(+Term, -Path, +Options)
  313%
  314%   Deal with the above expansion for :- include(program) to support
  315%   the cross-referencer.
  316
  317prolog:xref_source_file(stream(Id, _Stream, [close(true)]), Id, _).
  318prolog:xref_source_file(File, Id, Options) :-
  319    atom(File),
  320    option(relative_to(Src), Options),
  321    atom(Src),
  322    atom_concat('swish://', SrcFile, Src),
  323    add_extension(File, FileExt),
  324    file_directory_name(SrcFile, SrcDir),
  325    directory_file_path(SrcDir, FileExt, TargetFile),
  326    atom_concat('swish://', TargetFile, Id)