/* Part of SWI-Prolog Author: Jan Wielemaker E-mail: J.Wielemaker@vu.nl WWW: http://www.swi-prolog.org Copyright (c) 2011-2016, 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. */ /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This module binds the SWI-Prolog terminal I/O to the GNU readline library. Existence of this this library is detected by configure. Binding is achieved by rebinding the read function of the Sinput stream. This module only depends on the public interface as defined by SWI-Prolog.h and SWI-Stream.h - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ #include #include #include "SWI-Stream.h" #include "SWI-Prolog.h" #include #include #define DEBUG(level, g) (void)0 static IOFUNCTIONS rl_functions; /* IO+Terminal+Readline functions */ #if defined(HAVE_POLL_H) && defined(HAVE_POLL) #include #elif defined(HAVE_SYS_SELECT_H) #include #endif #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_UXNT_H #include #endif #ifdef HAVE_CLOCK #include #endif #ifdef HAVE_SYS_TIME_H #include #endif #ifdef __WINDOWS__ #include #endif #ifdef O_RLC #include "win32/console/console.h" #endif #ifdef HAVE_RL_INSERT_CLOSE #define PAREN_MATCHING 1 #endif #undef ESC /* will be redefined ... */ #include /* readline needs it */ #include #define savestring(x) /* avoid definition there */ #include extern int rl_done; /* should be in readline.h, but */ /* isn't in some versions ... */ #ifdef HAVE_READLINE_HISTORY_H #include #else extern void add_history(char *); /* should be in readline.h */ #endif /* missing prototypes in older */ /* readline.h versions */ extern int rl_begin_undo_group(void); /* delete when conflict arrises! */ extern int rl_end_undo_group(void); #ifndef HAVE_RL_FILENAME_COMPLETION_FUNCTION #define rl_filename_completion_function filename_completion_function extern char *filename_completion_function(const char *, int); #endif #ifndef HAVE_RL_COMPLETION_MATCHES #define rl_completion_matches completion_matches #endif #ifndef RL_STATE_INITIALIZED int rl_readline_state = 0; #define RL_STATE_INITIALIZED 0 #endif #ifndef HAVE_RL_SET_PROMPT #define rl_set_prompt(x) (void)0 #endif #ifndef HAVE_RL_CLEAR_PENDING_INPUT #define rl_clear_pending_input() (void)0 #endif #ifndef HAVE_RL_CLEANUP_AFTER_SIGNAL #define rl_cleanup_after_signal() (void)0 #endif #if !defined(HAVE_RL_DONE) && defined(HAVE_DECL_RL_DONE) && !HAVE_DECL_RL_DONE /* surely not provided, so we provide a dummy. We do this as a global symbol, so if there is one in a dynamic library it will work anyway. */ int rl_done; #endif static foreign_t pl_rl_read_init_file(term_t file) { char *f; if ( PL_get_file_name(file, &f, 0) ) { #ifdef O_XOS char buf[PATH_MAX]; rl_read_init_file(_xos_os_filename(f, buf)); #else rl_read_init_file(f); #endif PL_succeed; } PL_fail; } /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This is not really clear using wide-character handling. We now assume that the readline library can only do wide characters using UTF-8. Not sure this is true, but is certainly covers most installations. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ static char *hist_last = NULL; static foreign_t pl_rl_add_history(term_t text) { char *line; if ( PL_get_chars(text, &line, CVT_ATOM|CVT_STRING|REP_MB|CVT_EXCEPTION) ) { if ( hist_last && strcmp(hist_last,line) == 0 ) return FALSE; if ( hist_last ) free(hist_last); hist_last = strdup(line); add_history(line); return TRUE; } return FALSE; } static int file_error(term_t fn, const char *op, int rc) { switch(rc) { case EPERM: return PL_permission_error("file", op, fn); case ENOENT: return PL_existence_error("file", fn); default: return FALSE; /* TBD */ } } static foreign_t pl_rl_write_history(term_t fn) { char *s; int rc; if ( !PL_get_file_name(fn, &s, 0) ) return FALSE; if ( (rc=write_history(s)) == 0 ) return TRUE; return file_error(fn, "write", rc); } static foreign_t pl_rl_read_history(term_t fn) { char *s; int rc; if ( !PL_get_file_name(fn, &s, 0) ) return FALSE; if ( (rc=read_history(s)) == 0 ) return TRUE; return file_error(fn, "read", rc); } static char *my_prompt = NULL; static int in_readline = 0; static int sig_at_level = -1; /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Signal handling wrapper. This is tricky. The GNU readline library places signal handlers around the below given signals. They re-send all signals using kill(getpid(),sig). This goes wrong in our multi-threaded context as it will send signals meant for a thread (using pthread_kill()) to the wrong thread. The library time.pl from the clib package was victim of this behaviour. We disable readline's signal handling using rl_catch_signals = 0 and redo the work ourselves, where we call the handler directly instead of re-sending the signal. See "info readline" for details on readline signal handling issues. One of the problems is that the signal handler may not return after ^C . Earlier versions uses PL_abort_handler() to reset the basics, but since the introduction of multi-threading and exception-based aborts, this no longer works. We set sig_at_level to the current nesting level if we receive a signal. If this is still the current nesting level if we reach readling again we assumed we broke out of the old invocation in a non-convential manner. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ typedef struct { int signo; /* number of the signal */ struct sigaction old_state; /* old state for the signal */ } sigstate; static void rl_sighandler(int sig); static sigstate signals[] = { { SIGINT }, #ifdef SIGTSTP { SIGTSTP }, { SIGTTOU }, { SIGTTIN }, #endif { SIGALRM }, { SIGTERM }, { SIGQUIT }, { -1 }, }; static void prepare_signals(void) { sigstate *s; for(s=signals; s->signo != -1; s++) { struct sigaction new; memset(&new, 0, sizeof(new)); new.sa_handler = rl_sighandler; sigaction(s->signo, &new, &s->old_state); } } static void restore_signals(void) { sigstate *s; for(s=signals; s->signo != -1; s++) { sigaction(s->signo, &s->old_state, NULL); } } static void rl_sighandler(int sig) { sigstate *s; DEBUG(3, Sdprintf("Signal %d in readline\n", sig)); sig_at_level = in_readline; if ( sig == SIGINT ) rl_free_line_state (); rl_cleanup_after_signal (); restore_signals(); Sreset(); for(s=signals; s->signo != -1; s++) { if ( s->signo == sig ) { void (*func)(int) = s->old_state.sa_handler; if ( func == SIG_DFL ) { // TBD: unblockSignal(sig); DEBUG(3, Sdprintf("Re-sending signal\n")); PL_raise(sig); /* was: kill(getpid(), sig); */ } else if ( func != SIG_IGN ) { (*func)(sig); } break; } } DEBUG(3, Sdprintf("Resetting after signal\n")); prepare_signals(); rl_reset_after_signal(); } static char * pl_readline(const char *prompt) { char *line; prepare_signals(); line = readline(prompt); restore_signals(); return line; } /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The GNU-readline library is not reentrant (or does not appear to be so). Therefore we will detect this and simply call the default function if reentrant access is tried. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ #ifdef HAVE_RL_EVENT_HOOK static int input_on_fd(int fd) { #ifdef HAVE_POLL struct pollfd fds[1]; fds[0].fd = fd; fds[0].events = POLLIN; return poll(fds, 1, 0) != 0; #else fd_set rfds; struct timeval tv; #if defined(FD_SETSIZE) && !defined(__WINDOWS__) if ( fd >= FD_SETSIZE ) { Sdprintf("input_on_fd(%d) > FD_SETSIZE\n", fd); return 1; } #endif FD_ZERO(&rfds); FD_SET(fd, &rfds); tv.tv_sec = 0; tv.tv_usec = 0; return select(fd+1, &rfds, NULL, NULL, &tv) != 0; #endif } static int event_hook(void) { if ( Sinput->position ) { int64_t c0 = Sinput->position->charno; while( !input_on_fd(0) ) { PL_dispatch(0, PL_DISPATCH_NOWAIT); if ( Sinput->position->charno != c0 ) { if ( my_prompt ) rl_set_prompt(my_prompt); rl_forced_update_display(); c0 = Sinput->position->charno; rl_done = FALSE; } } } else PL_dispatch(0, PL_DISPATCH_WAIT); return TRUE; } #endif static void reset_readline(void) { if ( in_readline ) { restore_signals(); } if ( my_prompt ) { free(my_prompt); my_prompt = NULL; } in_readline = 0; } static ssize_t Sread_readline(void *handle, char *buf, size_t size) { intptr_t h = (intptr_t)handle; int fd = (int) h; int ttymode = PL_ttymode(Suser_input); /* Not so nice */ int rval; #ifdef HAVE_CLOCK intptr_t oldclock = clock(); #endif PL_write_prompt(ttymode == PL_NOTTY); switch( ttymode ) { case PL_RAWTTY: /* get_single_char/1 */ #ifdef O_RLC { int chr = getkey(); if ( chr == 04 || chr == 26 ) return 0; /* EOF */ buf[0] = chr & 0xff; return 1; } #endif case PL_NOTTY: /* -tty */ #ifdef RL_NO_REENTRANT notty: #endif { PL_dispatch(fd, PL_DISPATCH_WAIT); rval = read(fd, buf, size); if ( rval > 0 && buf[rval-1] == '\n' ) PL_prompt_next(fd); break; } case PL_COOKEDTTY: default: { char *line; const char *prompt; #ifdef RL_NO_REENTRANT if ( in_readline ) { Sprintf("[readline disabled] "); PL_write_prompt(TRUE); goto notty; /* avoid reentrance */ } #endif #ifdef HAVE_RL_EVENT_HOOK if ( PL_dispatch(0, PL_DISPATCH_INSTALLED) ) rl_event_hook = event_hook; else rl_event_hook = NULL; #endif prompt = PL_prompt_string(fd); if ( prompt ) PL_add_to_protocol(prompt, strlen(prompt)); { char *oldp = my_prompt; my_prompt = prompt ? strdup(prompt) : (char *)NULL; if ( sig_at_level == in_readline ) { sig_at_level = -1; reset_readline(); } if ( in_readline++ ) { int state = rl_readline_state; rl_clear_pending_input(); rl_discard_argument(); rl_deprep_terminal(); rl_readline_state = (RL_STATE_INITIALIZED); line = pl_readline(prompt); rl_prep_terminal(FALSE); rl_readline_state = state; rl_done = 0; } else line = pl_readline(prompt); in_readline--; if ( my_prompt ) free(my_prompt); my_prompt = oldp; } if ( line ) { size_t l = strlen(line); if ( l >= size ) { PL_warning("Input line too long"); /* must be tested! */ l = size-1; } memcpy(buf, line, l); buf[l++] = '\n'; rval = l; /*Sdprintf("Read: '%s'\n", line);*/ free(line); } else if ( PL_exception(0) ) { errno = EPLEXCEPTION; return -1; } else rval = 0; } } return rval; } static int prolog_complete(int ignore, int key) { if ( rl_point > 0 && rl_line_buffer[rl_point-1] != ' ' ) { rl_begin_undo_group(); rl_complete(ignore, key); if ( rl_point > 0 && rl_line_buffer[rl_point-1] == ' ' ) { #ifdef HAVE_RL_INSERT_CLOSE /* actually version >= 1.2 */ rl_delete_text(rl_point-1, rl_point); rl_point -= 1; #else rl_delete(-1, key); #endif } rl_end_undo_group(); } else rl_complete(ignore, key); return 0; } static char * atom_generator(const char *prefix, int state) { char *s = PL_atom_generator(prefix, state); if ( s ) { char *copy = malloc(1 + strlen(s)); if ( copy ) /* else pretend no completion */ strcpy(copy, s); s = copy; } return s; } static char ** prolog_completion(const char *text, int start, int end) { char **matches = NULL; if ( (start == 1 && rl_line_buffer[0] == '[') || /* [file */ (start == 2 && strncmp(rl_line_buffer, "['", 2)) ) matches = rl_completion_matches((char *)text, /* for pre-4.2 */ rl_filename_completion_function); else matches = rl_completion_matches((char *)text, atom_generator); return matches; } #undef read /* UXNT redefinition */ static foreign_t pl_rl_wrap(void) { if ( isatty(0) ) { rl_catch_signals = 0; rl_readline_name = "Prolog"; rl_attempted_completion_function = prolog_completion; #ifdef __WINDOWS__ rl_basic_word_break_characters = "\t\n\"\\'`@$><= [](){}+*!,|%&?"; #else rl_basic_word_break_characters = ":\t\n\"\\'`@$><= [](){}+*!,|%&?"; #endif rl_add_defun("prolog-complete", prolog_complete, '\t'); #if HAVE_RL_INSERT_CLOSE rl_add_defun("insert-close", rl_insert_close, ')'); #endif #if HAVE_RL_SET_KEYBOARD_INPUT_TIMEOUT /* see (*) */ rl_set_keyboard_input_timeout(20000); #endif rl_functions = *Sinput->functions; /* structure copy */ rl_functions.read = Sread_readline; /* read through readline */ Sinput->functions = &rl_functions; Soutput->functions = &rl_functions; Serror->functions = &rl_functions; PL_set_prolog_flag("readline", PL_ATOM, "readline"); PL_set_prolog_flag("tty_control", PL_BOOL, TRUE); } return TRUE; } /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - For some obscure reasons, notably libreadline 6 can show very bad interactive behaviour. There is a timeout set to 100000 (0.1 sec). It isn't particularly clear what this timeout is doing. I _think_ it should be synchronized PL_dispatch_hook(), and set to 0 if this hook is non-null. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ #ifdef __WINDOWS__ #define isatty(fd) TRUE #endif install_t install_readline4pl(void) { PL_license("gpl", "GNU Readline library"); #define PRED(name, arity, func, attr) \ PL_register_foreign_in_module("system", name, arity, func, attr) PRED("rl_read_init_file", 1, pl_rl_read_init_file, 0); PRED("rl_add_history", 1, pl_rl_add_history, PL_FA_NOTRACE); PRED("rl_write_history", 1, pl_rl_write_history, 0); PRED("rl_read_history", 1, pl_rl_read_history, 0); PRED("rl_wrap", 0, pl_rl_wrap, 0); }