text: /*  Part of SWI-Prolog
  
      Author:        Jan Wielemaker
      E-mail:        J.Wielemaker@vu.nl
      WWW:           http://www.swi-prolog.org
      Copyright (c)  1985-2020, University of Amsterdam
                                VU University Amsterdam
  			      CWI, 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.
  */
  
  /*#define O_DEBUG 1*/			/* include crash/0 */
  #include "pl-incl.h"
  #include "os/pl-ctype.h"
  
  #if O_DEBUG
  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  See how the system reacts on segmentation faults.
  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  
  static word
  pl_crash()
  { intptr_t *lp = NULL;
  
    Sdprintf("You asked for it ... Writing to address 0\n");
  
    *lp = 5;
  
    Sdprintf("Oops, this doesn't appear to be a secure OS\n");
  
    fail;
  }
  #endif
  
  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  Link all foreign language predicates.  The arguments to FRG are:
  
  	FRG(name, arity, function, flags).
  
  Flags almost always is TRACE_ME.  Additional common flags:
  
  	P_TRANSPARENT	Predicate is module transparent
  	P_NONDET	Predicate can be resatisfied
  
  Deprecated: the modern interface uses PRED_IMPL()
  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  
  #define NOTRACE PL_FA_NOTRACE
  #define META    PL_FA_TRANSPARENT
  #define NDET	PL_FA_NONDETERMINISTIC
  #define VA	PL_FA_VARARGS
  #define CREF	PL_FA_CREF
  #define ISO	PL_FA_ISO
  
  #define FRG(n, a, f, flags) { n, a, f, flags }
  
  static const PL_extension foreigns[] = {
  #if O_DEBUG
    FRG("crash",			0, pl_crash,			0),
  #endif
  #ifdef __WINDOWS__
    FRG("win_exec",		2, pl_win_exec,			0),
    FRG("win_module_file",	2, pl_win_module_file,		0),
  #endif
  
    FRG("halt",			1, pl_halt,		      ISO),
    FRG("getenv",			2, pl_getenv,			0),
    FRG("setenv",			2, pl_setenv,			0),
    FRG("unsetenv",		1, pl_unsetenv,			0),
    FRG("sub_atom",		5, pl_sub_atom,		 NDET|ISO),
    FRG("sleep",			1, pl_sleep,			0),
    FRG("break",			0, pl_break,			0),
  
    FRG("write_canonical",	1, pl_write_canonical,	      ISO),
    FRG("write_term",		2, pl_write_term,	 META|ISO),
    FRG("write_term",		3, pl_write_term3,	 META|ISO),
    FRG("write",			1, pl_write,		      ISO),
    FRG("writeq",			1, pl_writeq,		      ISO),
    FRG("writeln",		1, pl_writeln,		        0),
    FRG("print",			1, pl_print,			0),
  
    FRG("read",			1, pl_read,		      ISO),
    FRG("$raw_read",		1, pl_raw_read,			0),
    FRG("$raw_read",		2, pl_raw_read2,		0),
    FRG("current_functor",	2, pl_current_functor,	     NDET),
    FRG("char_conversion",	2, pl_char_conversion,	      ISO),
    FRG("current_char_conversion",2, pl_current_char_conversion, NDET|ISO),
  
    FRG("!",			0, pl_metacut,		      ISO),
  
    FRG("abolish",		1, pl_abolish1,		     META|ISO),
    FRG("abolish",		2, pl_abolish,		     META),
  #ifdef O_MAINTENANCE
    FRG("$list_generations",	1, pl_list_generations,	     META),
    FRG("$check_procedure",	1, pl_check_procedure,	     META),
  #endif
  
    FRG("$c_current_predicate",	2, pl_current_predicate,  NDET|META),
    FRG("$require",		1, pl_require,		     META),
  
    FRG("repeat",			0, pl_repeat,		 NDET|ISO),
    FRG("fail",			0, pl_fail,		      ISO),
    FRG("true",			0, pl_true,		      ISO),
    FRG("$fail",			0, pl_fail,		  NOTRACE),
  
    FRG("trace",			0, pl_trace,		  NOTRACE),
    FRG("notrace",		0, pl_notrace,		  NOTRACE),
    FRG("tracing",		0, pl_tracing,		  NOTRACE),
    FRG("$spy",			1, pl_spy,		     META),
    FRG("$nospy",			1, pl_nospy,		     META),
    FRG("$leash",			2, pl_leash,		  NOTRACE),
    FRG("$visible",		2, pl_visible,		  NOTRACE),
    FRG("$debuglevel",		2, pl_debuglevel,		0),
  
  #if COUNTING
    FRG("$count",			0, pl_count,			0),
  #endif /* COUNTING */
  
    FRG("prolog_current_frame",	1, pl_prolog_current_frame,	0),
  
    FRG("dwim_match",		3, pl_dwim_match,		0),
    FRG("$dwim_predicate",	2, pl_dwim_predicate,	     NDET),
  
  #ifdef O_PROLOG_HOOK
    FRG("set_prolog_hook",	3, pl_set_prolog_hook,	        0),
  #endif
    FRG("context_module",		1, pl_context_module,	     META),
  
  #if O_STRING
    FRG("sub_string",		5, pl_sub_string,	     NDET),
  #endif /* O_STRING */
  
    FRG("format",			2, pl_format,		     META),
  #ifdef O_DEBUG
    FRG("$check_definition",	1, pl_check_definition,      META),
  #endif
  
    FRG("$atom_hashstat",		2, pl_atom_hashstat,		0),
    FRG("$current_prolog_flag",	5, pl_prolog_flag5,	     NDET),
    FRG("current_prolog_flag",	2, pl_prolog_flag,	 NDET|ISO),
    FRG("$garbage_collect",	1, pl_garbage_collect,		0),
  #ifdef O_ATOMGC
    FRG("garbage_collect_atoms",	0, pl_garbage_collect_atoms,	0),
    FRG("garbage_collect_clauses", 0, pl_garbage_collect_clauses,	0),
  #ifdef O_DEBUG_ATOMGC
    FRG("track_atom",		2, pl_track_atom,		0),
  #endif
  #endif
    FRG("current_flag",		1, pl_current_flag,	     NDET),
  
    FRG("read",			2, pl_read2,		      ISO),
    FRG("write",			2, pl_write2,		      ISO),
    FRG("writeln",		2, pl_writeln2,		        0),
    FRG("writeq",			2, pl_writeq2,		      ISO),
    FRG("print",			2, pl_print2,			0),
    FRG("write_canonical",	2, pl_write_canonical2,	      ISO),
    FRG("format",			3, pl_format3,		     META),
  
    FRG("format_predicate",	2, pl_format_predicate,	     META),
    FRG("current_format_predicate", 2, pl_current_format_predicate,
  						        META|NDET),
    FRG("get_time",		1, pl_get_time,			0),
  
  #ifdef O_PLMT
    FRG("thread_create",		3, pl_thread_create,	 META|ISO),
    FRG("thread_exit",		1, pl_thread_exit,		0),
    FRG("thread_signal",		2, pl_thread_signal,	 META|ISO),
    FRG("open_xterm",		5, pl_open_xterm,		0),
  #endif
  
    FRG("thread_self",		1, pl_thread_self,	      ISO),
    FRG("with_mutex",		2, pl_with_mutex,	 META|ISO),
    FRG("$get_pid",		1, pl_get_pid,			0),
  
    /* DO NOT ADD ENTRIES BELOW THIS ONE */
    FRG((char *)NULL,		0, (Func)NULL,			0)
  };
  
  
  #define SIGNATURE_SEED (0x1a3be34a)
  
  static unsigned int
  predicate_signature(const Definition def)
  { char str[256];
  
    Ssprintf(str, "%s/%d/%d",
  	   stringAtom(def->functor->name),
  	   (int)def->functor->arity,
  	   def->flags);
  
    return MurmurHashAligned2(str, strlen(str), SIGNATURE_SEED);
  }
  
  
  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  The extensions chain is used   to allow calling PL_register_extensions()
  *before* PL_initialise() to get foreign   extensions in embedded systems
  defined before the state is loaded, so executing directives in the state
  can use foreign extensions.
  
  If an extension is registered before the  system extension is loaded, it
  will be added to the chain. Right  after the system registers the system
  predicates, the extensions will be registered.
  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  
  struct extension_cell
  { PL_extension *extensions;
    char *module;
    ExtensionCell next;
  };
  
  #define ext_head		(GD->foreign._ext_head)
  #define ext_tail		(GD->foreign._ext_tail)
  #define extensions_loaded	(GD->foreign._loaded)
  
  static char *
  dupStr(const char *str)
  { if (str)
    { size_t len = strlen(str)+1;
      char *m = PL_malloc(len);
      memcpy(m, str, len);
      return m;
    }
    return NULL;
  }
  
  
  static PL_extension *
  dupExtensions(const PL_extension *e)
  { int i;
    PL_extension *dup, *o;
    int len = 0;
  
    while(e[len++].predicate_name)
      ;
    o = dup = PL_malloc(len*sizeof(*e));
  
    for ( i=0; i<len; i++, o++, e++)
    { o->predicate_name = dupStr(e->predicate_name);
      o->arity = e->arity;
      o->function = e->function;
      o->flags = e->flags;
    }
  
    return dup;
  }
  
  
  void
  rememberExtensions(const char *module, const PL_extension *e)
  { ExtensionCell cell = PL_malloc(sizeof *cell);
  
    cell->extensions = dupExtensions(e);
    cell->next = NULL;
    cell->module = dupStr(module);
  
    if ( ext_tail )
    { ext_tail->next = cell;
      ext_tail = cell;
    } else
    { ext_head = ext_tail = cell;
    }
  }
  
  
  void
  cleanupExtensions(void)
  { ExtensionCell c, next;
  
    for(c=ext_head; c; c=next)
    { next = c->next;
      if (c->module)
        PL_free(c->module);
  
      if (c->extensions)
      { PL_extension *e = c->extensions;
  
        for(;e->predicate_name; e++)
  	PL_free((void *)e->predicate_name);
  
        PL_free(c->extensions);
      }
  
      PL_free(c);
    }
  
    ext_head = ext_tail = NULL;
  }
  
  
  
  static void
  registerBuiltins(const PL_extension *f)
  { Module m = MODULE_system;
  
    for(; f->predicate_name; f++)
    { Procedure proc;
      atom_t name	= PL_new_atom(f->predicate_name);
      functor_t fdef = lookupFunctorDef(name, f->arity);
  
      PL_unregister_atom(name);
      if ( (proc = lookupProcedure(fdef, m)) )
      { Definition def = proc->definition;
        set(def, P_FOREIGN|HIDE_CHILDS|P_LOCKED);
  
        if ( f->flags & PL_FA_NOTRACE )	       clear(def, TRACE_ME);
        if ( f->flags & PL_FA_TRANSPARENT )      set(def, P_TRANSPARENT);
        if ( f->flags & PL_FA_NONDETERMINISTIC ) set(def, P_NONDET);
        if ( f->flags & PL_FA_VARARGS )	       set(def, P_VARARG);
        if ( f->flags & PL_FA_CREF )	       set(def, P_FOREIGN_CREF);
        if ( f->flags & PL_FA_ISO )	       set(def, P_ISO);
  
        def->impl.foreign.function = f->function;
        createForeignSupervisor(def, f->function);
  
        if ( !extensions_loaded )
  	GD->foreign.signature ^= predicate_signature(def);
      } else
      { assert(0);
      }
    }
  }
  
  
  #define DECL_PLIST(id) \
  	extern const PL_extension PL_predicates_from_ ## id[]
  #define REG_PLIST(id) \
  	registerBuiltins(PL_predicates_from_ ## id)
  
  DECL_PLIST(alloc);
  DECL_PLIST(atom);
  DECL_PLIST(arith);
  DECL_PLIST(bag);
  DECL_PLIST(comp);
  DECL_PLIST(flag);
  DECL_PLIST(index);
  DECL_PLIST(init);
  DECL_PLIST(list);
  DECL_PLIST(module);
  DECL_PLIST(prims);
  DECL_PLIST(strings);
  DECL_PLIST(variant);
  DECL_PLIST(copyterm);
  DECL_PLIST(prologflag);
  DECL_PLIST(trace);
  DECL_PLIST(pro);
  DECL_PLIST(read);
  DECL_PLIST(thread);
  DECL_PLIST(profile);
  DECL_PLIST(wic);
  DECL_PLIST(attvar);
  DECL_PLIST(gvar);
  DECL_PLIST(win);
  DECL_PLIST(file);
  DECL_PLIST(files);
  DECL_PLIST(glob);
  DECL_PLIST(btree);
  DECL_PLIST(ctype);
  DECL_PLIST(tai);
  DECL_PLIST(setup);
  DECL_PLIST(gc);
  DECL_PLIST(proc);
  DECL_PLIST(srcfile);
  DECL_PLIST(write);
  DECL_PLIST(dlopen);
  DECL_PLIST(system);
  DECL_PLIST(op);
  DECL_PLIST(rec);
  DECL_PLIST(termhash);
  DECL_PLIST(dde);
  DECL_PLIST(term);
  DECL_PLIST(debug);
  DECL_PLIST(locale);
  DECL_PLIST(dict);
  DECL_PLIST(cont);
  DECL_PLIST(trie);
  DECL_PLIST(tabling);
  DECL_PLIST(mutex);
  DECL_PLIST(zip);
  DECL_PLIST(cbtrace);
  DECL_PLIST(wrap);
  DECL_PLIST(event);
  DECL_PLIST(transaction);
  
  void
  initBuildIns(void)
  { ExtensionCell ecell;
    Module m = MODULE_system;
  
    GD->procedures.dirty = newHTable(32);
  
    registerBuiltins(foreigns);
    REG_PLIST(alloc);
    REG_PLIST(atom);
    REG_PLIST(arith);
    REG_PLIST(bag);
    REG_PLIST(comp);
    REG_PLIST(flag);
    REG_PLIST(index);
    REG_PLIST(init);
    REG_PLIST(list);
    REG_PLIST(module);
    REG_PLIST(prims);
    REG_PLIST(strings);
    REG_PLIST(variant);
    REG_PLIST(copyterm);
    REG_PLIST(prologflag);
    REG_PLIST(trace);
    REG_PLIST(pro);
    REG_PLIST(read);
    REG_PLIST(thread);
    REG_PLIST(profile);
    REG_PLIST(wic);
    REG_PLIST(file);
    REG_PLIST(files);
    REG_PLIST(glob);
    REG_PLIST(btree);
    REG_PLIST(ctype);
    REG_PLIST(tai);
    REG_PLIST(setup);
    REG_PLIST(gc);
    REG_PLIST(proc);
    REG_PLIST(srcfile);
    REG_PLIST(write);
    REG_PLIST(dlopen);
    REG_PLIST(system);
    REG_PLIST(op);
    REG_PLIST(rec);
    REG_PLIST(term);
    REG_PLIST(termhash);
  #ifdef O_ATTVAR
    REG_PLIST(attvar);
  #endif
  #ifdef O_GVAR
    REG_PLIST(gvar);
  #endif
  #ifdef __WINDOWS__
    REG_PLIST(win);
    REG_PLIST(dde);
  #endif
  #ifdef O_LOCALE
    REG_PLIST(locale);
  #endif
    REG_PLIST(debug);
    REG_PLIST(dict);
    REG_PLIST(cont);
    REG_PLIST(trie);
    REG_PLIST(tabling);
    REG_PLIST(mutex);
    REG_PLIST(zip);
    REG_PLIST(cbtrace);
    REG_PLIST(wrap);
    REG_PLIST(event);
    REG_PLIST(transaction);
  
  #define LOOKUPPROC(name) \
  	{ GD->procedures.name = lookupProcedure(FUNCTOR_ ## name, m); \
  	  DEBUG(CHK_SECURE, assert(GD->procedures.name)); \
  	}
  
    LOOKUPPROC(dgarbage_collect1);
    LOOKUPPROC(catch3);
    LOOKUPPROC(reset3);
    LOOKUPPROC(dmeta_call1);
    LOOKUPPROC(true0);
    LOOKUPPROC(fail0);
    LOOKUPPROC(equals2);
    LOOKUPPROC(is2);
    LOOKUPPROC(strict_equal2);
    LOOKUPPROC(not_strict_equal2);
    LOOKUPPROC(arg3);
    LOOKUPPROC(print_message2);
    LOOKUPPROC(dcall1);
    LOOKUPPROC(setup_call_catcher_cleanup4);
    LOOKUPPROC(dthread_init0);
    LOOKUPPROC(dc_call_prolog0);
    LOOKUPPROC(dinit_goal3);
  #ifdef O_ATTVAR
    LOOKUPPROC(dwakeup1);
  #endif
    PROCEDURE_exception_hook4  =
  	PL_predicate("prolog_exception_hook", 4, "user");
    PROCEDURE_tune_gc3 =
  	PL_predicate("tune_gc", 3, "prolog");
  					/* allow debugging in call/1 */
    clear(PROCEDURE_dcall1->definition, HIDE_CHILDS|TRACE_ME);
    set(PROCEDURE_dcall1->definition, P_DYNAMIC|P_LOCKED);
  
    PL_meta_predicate(PL_predicate("assert",           1, "system"), ":");
    PL_meta_predicate(PL_predicate("asserta",          1, "system"), ":");
    PL_meta_predicate(PL_predicate("assertz",          1, "system"), ":");
    PL_meta_predicate(PL_predicate("assert",           2, "system"), ":-");
    PL_meta_predicate(PL_predicate("asserta",          2, "system"), ":-");
    PL_meta_predicate(PL_predicate("assertz",          2, "system"), ":-");
    PL_meta_predicate(PL_predicate("retract",          1, "system"), ":");
    PL_meta_predicate(PL_predicate("retractall",       1, "system"), ":");
    PL_meta_predicate(PL_predicate("clause",           2, "system"), ":?");
  
    PL_meta_predicate(PL_predicate("format",           2, "system"), "+:");
    PL_meta_predicate(PL_predicate("format",           3, "system"), "++:");
    PL_meta_predicate(PL_predicate("format_predicate", 2, "system"), "+0");
  
    PL_meta_predicate(PL_predicate("notrace",          1, "system"), "0");
    PL_meta_predicate(PL_predicate("with_mutex",       2, "system"), "+0");
    PL_meta_predicate(PL_predicate("with_output_to",   2, "system"), "+0");
  #ifdef O_PLMT
    PL_meta_predicate(PL_predicate("thread_create",    3, "system"), "0?+");
    PL_meta_predicate(PL_predicate("thread_signal",    2, "system"), "+0");
    PL_meta_predicate(PL_predicate("thread_wait",	     2, "system"), "0:");
    PL_meta_predicate(PL_predicate("thread_update",    2, "system"), "0:");
  #endif
    PL_meta_predicate(PL_predicate("thread_idle",      2, "system"), "0+");
    PL_meta_predicate(PL_predicate("prolog_frame_attribute", 3, "system"), "++:");
    PL_meta_predicate(PL_predicate("compile_predicates", 1, "system"), ":");
    PL_meta_predicate(PL_predicate("op",		     3, "system"), "++:");
    PL_meta_predicate(PL_predicate("current_op",	     3, "system"), "++:");
    PL_meta_predicate(PL_predicate("unwrap_predicate", 2, "system"), ":?");
    PL_meta_predicate(PL_predicate("prolog_listen",    2, "system"), "+:");
    PL_meta_predicate(PL_predicate("prolog_listen",    3, "system"), "+:+");
    PL_meta_predicate(PL_predicate("prolog_unlisten",  2, "system"), "+:");
    PL_meta_predicate(PL_predicate("with_tty_raw",     1, "system"), "0");
    PL_meta_predicate(PL_predicate("$sig_atomic",      1, "system"), "0");
  
    for( ecell = ext_head; ecell; ecell = ecell->next )
      bindExtensions(ecell->module, ecell->extensions);
  
    extensions_loaded = TRUE;
  }
  