456 lines
11 KiB
C
456 lines
11 KiB
C
/*************************************************************************
|
|
* *
|
|
* YAP Prolog *
|
|
* *
|
|
* Yap Prolog was developed at NCCUP - Universidade do Porto *
|
|
* *
|
|
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
|
|
* *
|
|
**************************************************************************
|
|
* *
|
|
* File: alias.c *
|
|
* Last rev: 5/2/88 *
|
|
* mods: *
|
|
* comments: Input/Output C implemented predicates *
|
|
* *
|
|
*************************************************************************/
|
|
#ifdef SCCS
|
|
static char SccsId[] = "%W% %G%";
|
|
#endif
|
|
|
|
/**
|
|
* @file alias.c
|
|
* @author VITOR SANTOS COSTA <vsc@VITORs-MBP.lan>
|
|
* @date Thu Nov 19 10:53:20 2015
|
|
*
|
|
* @brief File Aliases
|
|
*
|
|
*
|
|
*/
|
|
|
|
|
|
/**
|
|
* @defgroup Aliases
|
|
* @ingroup InputOutput
|
|
*
|
|
* Aliases:
|
|
* This file defines the main operations on aliases, a second name for a file. Aliases are always
|
|
* textual constants (atoms).
|
|
*
|
|
* Their first advantage is that they allow cleaning up code, by separating name from operation, eg
|
|
* YAP has a loop stream used to run the main top-level, which can be std0 originally but then
|
|
* changed to a pipe, a file, or a memory region. Other important streams are the user streams. Finally,
|
|
* the debugger uses debugger input and output.
|
|
*
|
|
* Predefined stream aliases are:
|
|
* + user: special alias, initially refers to all the three standard streams.
|
|
* + `user_input: initially refers to the stdandard input stream;
|
|
* + `user_output: initially refers to the stdandard output stream;
|
|
* + `user_error: initially refers to the stdandard error stream. Often this is the same device
|
|
* as `stderr`, just accessed in different ways.
|
|
* + loop_stream: refers to the stream for the file or object being current consulted
|
|
* + debugger_input: refers to the stream used to send debugger commands, by default `user_input`.
|
|
* It must always be interactive.
|
|
*/
|
|
|
|
#include "sysbits.h"
|
|
#if HAVE_FCNTL_H
|
|
/* for O_BINARY and O_TEXT in WIN32 */
|
|
#include <fcntl.h>
|
|
#endif
|
|
#include "Yatom.h"
|
|
#include "YapHeap.h"
|
|
#include "yapio.h"
|
|
#include "eval.h"
|
|
#include "YapText.h"
|
|
#include <stdlib.h>
|
|
#if HAVE_STDARG_H
|
|
#include <stdarg.h>
|
|
#endif
|
|
#ifdef HAVE_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif
|
|
#if HAVE_CTYPE_H
|
|
#include <ctype.h>
|
|
#endif
|
|
#if HAVE_WCTYPE_H
|
|
#include <wctype.h>
|
|
#endif
|
|
#if HAVE_SYS_PARAM_H
|
|
#include <sys/param.h>
|
|
#endif
|
|
#if HAVE_SYS_TIME_H
|
|
#include <sys/time.h>
|
|
#endif
|
|
#if HAVE_SYS_TYPES_H
|
|
#include <sys/types.h>
|
|
#endif
|
|
#ifdef HAVE_SYS_STAT_H
|
|
#include <sys/stat.h>
|
|
#endif
|
|
#if HAVE_SYS_SELECT_H && !_MSC_VER && !defined(__MINGW32__)
|
|
#include <sys/select.h>
|
|
#endif
|
|
#if HAVE_STRING_H
|
|
#include <string.h>
|
|
#endif
|
|
#if HAVE_SIGNAL_H
|
|
#include <signal.h>
|
|
#endif
|
|
#ifdef _WIN32
|
|
// WIN32 API support
|
|
#if HAVE_IO_H
|
|
/* Windows */
|
|
#include <io.h>
|
|
#endif
|
|
#endif
|
|
|
|
#if _MSC_VER || defined(__MINGW32__)
|
|
#if HAVE_SOCKET
|
|
#include <winsock2.h>
|
|
#endif
|
|
#include <windows.h>
|
|
#endif
|
|
#include "iopreds.h"
|
|
|
|
#if _MSC_VER || defined(__MINGW32__)
|
|
#define SYSTEM_STAT _stat
|
|
#else
|
|
#define SYSTEM_STAT stat
|
|
#endif
|
|
|
|
static Atom FetchAlias (int sno);
|
|
static bool ExistsAliasForStream (int sno, Atom al);
|
|
|
|
/**
|
|
* Specify an alias to the stream. The alias <tt>Name</tt> must be an atom. The
|
|
* alias can be used instead of the stream descriptor for every operation
|
|
* concerning the stream.
|
|
*
|
|
* @param + _tname_ Name of Alias
|
|
* @param + _tstream_ stream identifier
|
|
*
|
|
* @return
|
|
*/
|
|
static Int add_alias_to_stream (USES_REGS1)
|
|
{
|
|
Term tname = Deref(ARG1);
|
|
Term tstream = Deref(ARG2);
|
|
Atom at;
|
|
Int sno;
|
|
|
|
if (IsVarTerm(tname)) {
|
|
Yap_Error(INSTANTIATION_ERROR, tname, "$add_alias_to_stream");
|
|
return (FALSE);
|
|
} else if (!IsAtomTerm (tname)) {
|
|
Yap_Error(TYPE_ERROR_ATOM, tname, "$add_alias_to_stream");
|
|
return (FALSE);
|
|
}
|
|
if (IsVarTerm(tstream)) {
|
|
Yap_Error(INSTANTIATION_ERROR, tstream, "$add_alias_to_stream");
|
|
return (FALSE);
|
|
} else if (!IsApplTerm (tstream) || FunctorOfTerm (tstream) != FunctorStream ||
|
|
!IsIntTerm(ArgOfTerm(1,tstream))) {
|
|
Yap_Error(DOMAIN_ERROR_STREAM_OR_ALIAS, tstream, "$add_alias_to_stream");
|
|
return (FALSE);
|
|
}
|
|
at = AtomOfTerm(tname);
|
|
sno = (int)IntOfTerm(ArgOfTerm(1,tstream));
|
|
if (Yap_AddAlias(at, sno))
|
|
return(TRUE);
|
|
/* we could not create the alias, time to close the stream */
|
|
Yap_CloseStream(sno);
|
|
Yap_Error(PERMISSION_ERROR_NEW_ALIAS_FOR_STREAM, tname, "open/3");
|
|
return (FALSE);
|
|
}
|
|
|
|
static Int check_if_valid_new_alias (USES_REGS1)
|
|
{
|
|
Term tname = Deref(ARG1);
|
|
Atom at;
|
|
|
|
if (IsVarTerm(tname)) {
|
|
Yap_Error(INSTANTIATION_ERROR, tname, "$add_alias_to_stream");
|
|
return (FALSE);
|
|
} else if (!IsAtomTerm (tname)) {
|
|
Yap_Error(TYPE_ERROR_ATOM, tname, "$add_alias_to_stream");
|
|
return (FALSE);
|
|
}
|
|
at = AtomOfTerm(tname);
|
|
return(Yap_CheckAlias(at) == -1);
|
|
}
|
|
|
|
|
|
bool
|
|
Yap_FetchStreamAlias (int sno, Term t2 USES_REGS)
|
|
{
|
|
|
|
if (IsVarTerm(t2)) {
|
|
Atom at = FetchAlias(sno);
|
|
if (at == NULL)
|
|
return false;
|
|
else {
|
|
return Yap_unify_constant(t2, MkAtomTerm(at));
|
|
}
|
|
} else if (IsAtomTerm(t2)) {
|
|
Atom at = AtomOfTerm(t2);
|
|
return ExistsAliasForStream(sno,at);
|
|
} else {
|
|
Yap_Error(TYPE_ERROR_ATOM, t2, "stream_property(_,alias( ))");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static void
|
|
ExtendAliasArray(void)
|
|
{
|
|
CACHE_REGS
|
|
AliasDesc new;
|
|
UInt new_size = GLOBAL_SzOfFileAliases+ALIASES_BLOCK_SIZE;
|
|
|
|
new = (AliasDesc)Yap_AllocCodeSpace(sizeof(AliasDesc *)*new_size);
|
|
memcpy((void *)new, (void *)GLOBAL_FileAliases, sizeof(AliasDesc *)*GLOBAL_SzOfFileAliases);
|
|
Yap_FreeCodeSpace((ADDR) GLOBAL_FileAliases);
|
|
GLOBAL_FileAliases = new;
|
|
GLOBAL_SzOfFileAliases = new_size;
|
|
}
|
|
|
|
void
|
|
Yap_SetAlias (Atom arg, int sno)
|
|
{
|
|
CACHE_REGS
|
|
AliasDesc aliasp = GLOBAL_FileAliases, aliasp_max = GLOBAL_FileAliases+GLOBAL_NOfFileAliases;
|
|
|
|
while (aliasp < aliasp_max) {
|
|
// replace alias
|
|
if (aliasp->name == arg) {
|
|
Int alno = aliasp-GLOBAL_FileAliases;
|
|
aliasp->alias_stream = sno;
|
|
if (!(GLOBAL_Stream[sno].status &
|
|
(Null_Stream_f|InMemory_Stream_f|Socket_Stream_f))) {
|
|
switch(alno) {
|
|
case 0:
|
|
Yap_stdin = GLOBAL_Stream[sno].file;
|
|
break;
|
|
case 1:
|
|
Yap_stdout = GLOBAL_Stream[sno].file;
|
|
break;
|
|
case 2:
|
|
Yap_stderr = GLOBAL_Stream[sno].file;
|
|
#if HAVE_SETBUF
|
|
setvbuf (GLOBAL_Stream[sno].file, NULL, _IONBF, 0);
|
|
#endif /* HAVE_SETBUF */
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
aliasp++;
|
|
}
|
|
// set new alias
|
|
/* we have not found an alias, create one */
|
|
if (aliasp == GLOBAL_FileAliases+ GLOBAL_SzOfFileAliases)
|
|
ExtendAliasArray();
|
|
GLOBAL_NOfFileAliases++;
|
|
aliasp->name = arg;
|
|
aliasp->alias_stream = sno;
|
|
}
|
|
|
|
/* purge all aliases for stream sno */
|
|
void
|
|
Yap_DeleteAliases (int sno)
|
|
{
|
|
CACHE_REGS
|
|
AliasDesc aliasp = GLOBAL_FileAliases, aliasp_max = GLOBAL_FileAliases+ GLOBAL_NOfFileAliases, new_aliasp = aliasp;
|
|
|
|
while (aliasp < aliasp_max) {
|
|
if (aliasp->alias_stream == sno) {
|
|
if (aliasp - GLOBAL_FileAliases < 3) {
|
|
/* get back to std streams, but keep alias around */
|
|
Int alno = aliasp-GLOBAL_FileAliases;
|
|
new_aliasp->alias_stream = alno;
|
|
switch(alno) {
|
|
case 0:
|
|
Yap_stdin = stdin;
|
|
break;
|
|
case 1:
|
|
Yap_stdout = stdout;
|
|
break;
|
|
case 2:
|
|
Yap_stderr = stderr;
|
|
break; /* just put something here */
|
|
}
|
|
new_aliasp++;
|
|
} else {
|
|
GLOBAL_NOfFileAliases--;
|
|
// printf("RM %p at %d/%d %d\n", new_aliasp->name, new_aliasp-GLOBAL_FileAliases, new_aliasp->alias_stream, sno);
|
|
}
|
|
} else {
|
|
/* avoid holes in alias array */
|
|
if (new_aliasp != aliasp) {
|
|
new_aliasp->alias_stream = aliasp->alias_stream;
|
|
new_aliasp->name = aliasp->name;
|
|
}
|
|
new_aliasp++;
|
|
}
|
|
aliasp++;
|
|
}/////
|
|
}
|
|
|
|
/* check if name is an alias */
|
|
int
|
|
Yap_CheckAlias (Atom arg)
|
|
{
|
|
CACHE_REGS
|
|
AliasDesc aliasp = GLOBAL_FileAliases, aliasp_max = GLOBAL_FileAliases+GLOBAL_NOfFileAliases;
|
|
|
|
|
|
while (aliasp < aliasp_max) {
|
|
if (aliasp->name == arg) {
|
|
return(aliasp->alias_stream);
|
|
}
|
|
aliasp++;
|
|
}
|
|
return(-1);
|
|
}
|
|
|
|
/* check if stream has an alias */
|
|
static Atom
|
|
FetchAlias (int sno)
|
|
{
|
|
CACHE_REGS
|
|
AliasDesc aliasp = GLOBAL_FileAliases, aliasp_max = GLOBAL_FileAliases+GLOBAL_NOfFileAliases;
|
|
|
|
while (aliasp < aliasp_max) {
|
|
if (aliasp->alias_stream == sno) {
|
|
return(aliasp->name);
|
|
}
|
|
aliasp++;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* check if arg is an alias */
|
|
static bool
|
|
ExistsAliasForStream (int sno, Atom al)
|
|
{
|
|
CACHE_REGS
|
|
AliasDesc aliasp = GLOBAL_FileAliases, aliasp_max = GLOBAL_FileAliases+GLOBAL_NOfFileAliases;
|
|
|
|
while (aliasp < aliasp_max) {
|
|
if (aliasp->alias_stream == sno && aliasp->name == al) {
|
|
return true;
|
|
}
|
|
aliasp++;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* check if arg is an alias */
|
|
bool
|
|
Yap_FindStreamForAlias (Atom al)
|
|
{
|
|
CACHE_REGS
|
|
AliasDesc aliasp = GLOBAL_FileAliases,
|
|
aliasp_max = GLOBAL_FileAliases+GLOBAL_NOfFileAliases;
|
|
|
|
while (aliasp < aliasp_max) {
|
|
if (aliasp->name == al) {
|
|
return aliasp->alias_stream;
|
|
}
|
|
aliasp++;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* create a new alias arg for stream sno */
|
|
int
|
|
Yap_RemoveAlias (Atom arg, int sno)
|
|
{
|
|
CACHE_REGS
|
|
|
|
AliasDesc aliasp = GLOBAL_FileAliases, aliasp_max = GLOBAL_FileAliases+GLOBAL_NOfFileAliases;
|
|
|
|
while (aliasp < aliasp_max) {
|
|
if (aliasp->name == arg) {
|
|
if (aliasp->alias_stream != sno) {
|
|
return(FALSE);
|
|
}
|
|
return(TRUE);
|
|
}
|
|
aliasp++;
|
|
}
|
|
//printf("RM %p at %d\n", arg, aliasp-GLOBAL_FileAliases);
|
|
/* we have not found an alias neither a hole */
|
|
if (aliasp == GLOBAL_FileAliases+GLOBAL_SzOfFileAliases)
|
|
ExtendAliasArray();
|
|
GLOBAL_NOfFileAliases--;
|
|
aliasp->name = arg;
|
|
aliasp->alias_stream = sno;
|
|
return(TRUE);
|
|
}
|
|
|
|
/* create a new alias arg for stream sno */
|
|
bool
|
|
Yap_AddAlias (Atom arg, int sno)
|
|
{
|
|
CACHE_REGS
|
|
|
|
AliasDesc aliasp = GLOBAL_FileAliases, aliasp_max = GLOBAL_FileAliases+GLOBAL_NOfFileAliases;
|
|
|
|
while (aliasp < aliasp_max) {
|
|
if (aliasp->name == arg) {
|
|
aliasp->alias_stream = sno;
|
|
return true;
|
|
}
|
|
aliasp++;
|
|
}
|
|
/* we have not found an alias neither a hole */
|
|
if (aliasp == GLOBAL_FileAliases+GLOBAL_SzOfFileAliases)
|
|
ExtendAliasArray();
|
|
GLOBAL_NOfFileAliases++;
|
|
// printf("ADD %p at %d\n", arg, aliasp-GLOBAL_FileAliases);
|
|
aliasp->name = arg;
|
|
aliasp->alias_stream = sno;
|
|
return true;
|
|
}
|
|
|
|
/* create a new alias arg for stream sno */
|
|
struct AliasDescS *
|
|
Yap_InitStandardAliases(void)
|
|
{
|
|
CACHE_REGS
|
|
/* init standard aliases */
|
|
|
|
/* alloca alias array */
|
|
GLOBAL_FileAliases = (AliasDesc)Yap_AllocCodeSpace(sizeof(struct AliasDescS)*ALIASES_BLOCK_SIZE);
|
|
|
|
if (GLOBAL_FileAliases == NULL)
|
|
return NULL;
|
|
|
|
GLOBAL_FileAliases[0].name = AtomUserIn;
|
|
GLOBAL_FileAliases[0].alias_stream = 0;
|
|
GLOBAL_FileAliases[1].name = AtomUserOut;
|
|
GLOBAL_FileAliases[1].alias_stream = 1;
|
|
GLOBAL_FileAliases[2].name = AtomUserErr;
|
|
GLOBAL_FileAliases[2].alias_stream = 2;
|
|
GLOBAL_FileAliases[3].name = AtomLoopStream;
|
|
GLOBAL_FileAliases[3].alias_stream = 0;
|
|
GLOBAL_FileAliases[4].name = AtomDebuggerInput;
|
|
GLOBAL_FileAliases[4].alias_stream = 0;
|
|
GLOBAL_NOfFileAliases = 5;
|
|
GLOBAL_SzOfFileAliases = ALIASES_BLOCK_SIZE;
|
|
|
|
return GLOBAL_FileAliases;
|
|
}
|
|
|
|
/* create a new alias arg for stream sno */
|
|
void
|
|
Yap_InitAliases(void)
|
|
{
|
|
Yap_InitCPred ("$check_if_valid_new_alias", 1, check_if_valid_new_alias, TestPredFlag|SafePredFlag|SyncPredFlag|HiddenPredFlag);
|
|
Yap_InitCPred ("$add_alias_to_stream", 2, add_alias_to_stream, SafePredFlag|SyncPredFlag|HiddenPredFlag);
|
|
}
|