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IABSD.fr/src/lib/libedit/read.c

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  • Author : schwarze
    Date : 2021-08-13 10:21:25
    Hash : 2a75a88e
    Message : Stop using a while loop for code that runs at most once, and garbage collect an automatic variable that is no longer needed and a comment that was probably contributed by Capt. Obvious. No functional change. OK millert@ martijn@

  • lib/libedit/read.c
  • /*	$OpenBSD: read.c,v 1.49 2021/08/13 10:21:25 schwarze Exp $	*/
    /*	$NetBSD: read.c,v 1.100 2016/05/24 19:31:27 christos Exp $	*/
    
    /*-
     * Copyright (c) 1992, 1993
     *	The Regents of the University of California.  All rights reserved.
     *
     * This code is derived from software contributed to Berkeley by
     * Christos Zoulas of Cornell University.
     *
     * 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.
     * 3. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
     */
    
    #include "config.h"
    
    /*
     * read.c: Clean this junk up! This is horrible code.
     *	   Terminal read functions
     */
    #include <sys/ioctl.h>
    
    #include <ctype.h>
    #include <errno.h>
    #include <limits.h>
    #include <stdlib.h>
    #include <string.h>
    #include <unistd.h>
    
    #include "el.h"
    #include "fcns.h"
    #include "read.h"
    
    #define	EL_MAXMACRO	10
    
    struct macros {
    	wchar_t	**macro;
    	int	  level;
    	int	  offset;
    };
    
    struct el_read_t {
    	struct macros	 macros;
    	el_rfunc_t	 read_char;	/* Function to read a character. */
    	int		 read_errno;
    };
    
    static int	read_char(EditLine *, wchar_t *);
    static int	read_getcmd(EditLine *, el_action_t *, wchar_t *);
    static void	read_clearmacros(struct macros *);
    static void	read_pop(struct macros *);
    
    /* read_init():
     *	Initialize the read stuff
     */
    protected int
    read_init(EditLine *el)
    {
    	struct macros *ma;
    
    	if ((el->el_read = malloc(sizeof(*el->el_read))) == NULL)
    		return -1;
    
    	ma = &el->el_read->macros;
    	if ((ma->macro = reallocarray(NULL, EL_MAXMACRO,
    	    sizeof(*ma->macro))) == NULL) {
    		free(el->el_read);
    		return -1;
    	}
    	ma->level = -1;
    	ma->offset = 0;
    
    	/* builtin read_char */
    	el->el_read->read_char = read_char;
    	return 0;
    }
    
    /* el_read_end():
     *	Free the data structures used by the read stuff.
     */
    protected void
    read_end(struct el_read_t *el_read)
    {
    	read_clearmacros(&el_read->macros);
    	free(el_read->macros.macro);
    	el_read->macros.macro = NULL;
    }
    
    /* el_read_setfn():
     *	Set the read char function to the one provided.
     *	If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
     */
    protected int
    el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
    {
    	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
    	return 0;
    }
    
    
    /* el_read_getfn():
     *	return the current read char function, or EL_BUILTIN_GETCFN
     *	if it is the default one
     */
    protected el_rfunc_t
    el_read_getfn(struct el_read_t *el_read)
    {
    	return el_read->read_char == read_char ?
    	    EL_BUILTIN_GETCFN : el_read->read_char;
    }
    
    
    /* el_push():
     *	Push a macro
     */
    void
    el_wpush(EditLine *el, const wchar_t *str)
    {
    	struct macros *ma = &el->el_read->macros;
    
    	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
    		ma->level++;
    		if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
    			return;
    		ma->level--;
    	}
    	terminal_beep(el);
    	terminal__flush(el);
    }
    
    
    /* read_getcmd():
     *	Get next command from the input stream,
     *	return 0 on success or -1 on EOF or error.
     *	Character values > 255 are not looked up in the map, but inserted.
     */
    static int
    read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
    {
    	static const wchar_t meta = (wchar_t)0x80;
    	el_action_t cmd;
    	int num;
    
    	do {
    		if ((num = el_wgetc(el, ch)) != 1)
    			return -1;
    
    #ifdef	KANJI
    		if ((*ch & meta)) {
    			el->el_state.metanext = 0;
    			cmd = CcViMap[' '];
    			break;
    		} else
    #endif /* KANJI */
    
    		if (el->el_state.metanext) {
    			el->el_state.metanext = 0;
    			*ch |= meta;
    		}
    		if (*ch >= N_KEYS)
    			cmd = ED_INSERT;
    		else
    			cmd = el->el_map.current[(unsigned char) *ch];
    		if (cmd == ED_SEQUENCE_LEAD_IN) {
    			keymacro_value_t val;
    			switch (keymacro_get(el, ch, &val)) {
    			case XK_CMD:
    				cmd = val.cmd;
    				break;
    			case XK_STR:
    				el_wpush(el, val.str);
    				break;
    			case XK_NOD:
    				return -1;
    			default:
    				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
    				break;
    			}
    		}
    	} while (cmd == ED_SEQUENCE_LEAD_IN);
    	*cmdnum = cmd;
    	return 0;
    }
    
    /* read_char():
     *	Read a character from the tty.
     */
    static int
    read_char(EditLine *el, wchar_t *cp)
    {
    	char cbuf[MB_LEN_MAX];
    	int cbp = 0;
    
     again:
    	el->el_signal->sig_no = 0;
    	switch (read(el->el_infd, cbuf + cbp, 1)) {
    	case -1:
    		if (errno == EINTR) {
    			switch (el->el_signal->sig_no) {
    			case SIGCONT:
    				el_set(el, EL_REFRESH);
    				/*FALLTHROUGH*/
    			case SIGWINCH:
    				sig_set(el);
    				goto again;
    			default:
    				break;
    			}
    		}
    		*cp = L'\0';
    		return -1;
    	case 0:
    		*cp = L'\0';
    		return 0;
    	default:
    		break;
    	}
    
    	for (;;) {
    		mbstate_t mbs;
    
    		++cbp;
    		/* This only works because UTF8 is stateless. */
    		memset(&mbs, 0, sizeof(mbs));
    		switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
    		case (size_t)-1:
    			if (cbp > 1) {
    				/*
    				 * Invalid sequence, discard all bytes
    				 * except the last one.
    				 */
    				cbuf[0] = cbuf[cbp - 1];
    				cbp = 0;
    				break;
    			} else {
    				/* Invalid byte, discard it. */
    				cbp = 0;
    				goto again;
    			}
    		case (size_t)-2:
    			/*
    			 * We don't support other multibyte charsets.
    			 * The second condition shouldn't happen
    			 * and is here merely for additional safety.
    			 */
    			if ((el->el_flags & CHARSET_IS_UTF8) == 0 ||
    			    cbp >= MB_LEN_MAX) {
    				errno = EILSEQ;
    				*cp = L'\0';
    				return -1;
    			}
    			/* Incomplete sequence, read another byte. */
    			goto again;
    		default:
    			/* Valid character, process it. */
    			return 1;
    		}
    	}
    }
    
    /* read_pop():
     *	Pop a macro from the stack
     */
    static void
    read_pop(struct macros *ma)
    {
    	int i;
    
    	free(ma->macro[0]);
    	for (i = 0; i < ma->level; i++)
    		ma->macro[i] = ma->macro[i + 1];
    	ma->level--;
    	ma->offset = 0;
    }
    
    static void
    read_clearmacros(struct macros *ma)
    {
    	while (ma->level >= 0)
    		free(ma->macro[ma->level--]);
    	ma->offset = 0;
    }
    
    /* el_wgetc():
     *	Read a wide character
     */
    int
    el_wgetc(EditLine *el, wchar_t *cp)
    {
    	struct macros *ma = &el->el_read->macros;
    	int num_read;
    
    	terminal__flush(el);
    	for (;;) {
    		if (ma->level < 0)
    			break;
    
    		if (ma->macro[0][ma->offset] == '\0') {
    			read_pop(ma);
    			continue;
    		}
    
    		*cp = ma->macro[0][ma->offset++];
    
    		if (ma->macro[0][ma->offset] == '\0') {
    			/* Needed for QuoteMode On */
    			read_pop(ma);
    		}
    
    		return 1;
    	}
    
    	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
    		return 0;
    
    	num_read = (*el->el_read->read_char)(el, cp);
    
    	/*
    	 * Remember the original reason of a read failure
    	 * such that el_wgets() can restore it after doing
    	 * various cleanup operation that might change errno.
    	 */
    	if (num_read < 0)
    		el->el_read->read_errno = errno;
    
    	return num_read;
    }
    
    protected void
    read_prepare(EditLine *el)
    {
    	if (el->el_flags & HANDLE_SIGNALS)
    		sig_set(el);
    	if (el->el_flags & NO_TTY)
    		return;
    	if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
    		tty_rawmode(el);
    
    	/* This is relatively cheap, and things go terribly wrong if
    	   we have the wrong size. */
    	el_resize(el);
    	re_clear_display(el);	/* reset the display stuff */
    	ch_reset(el);
    	re_refresh(el);		/* print the prompt */
    
    	if (el->el_flags & UNBUFFERED)
    		terminal__flush(el);
    }
    
    protected void
    read_finish(EditLine *el)
    {
    	if ((el->el_flags & UNBUFFERED) == 0)
    		(void) tty_cookedmode(el);
    	if (el->el_flags & HANDLE_SIGNALS)
    		sig_clr(el);
    }
    
    const wchar_t *
    el_wgets(EditLine *el, int *nread)
    {
    	int retval;
    	el_action_t cmdnum = 0;
    	int num;		/* how many chars we have read at NL */
    	wchar_t wc;
    	wchar_t ch, *cp;
    	int crlf = 0;
    	int nrb;
    
    	if (nread == NULL)
    		nread = &nrb;
    	*nread = 0;
    	el->el_read->read_errno = 0;
    
    	if (el->el_flags & NO_TTY) {
    		size_t idx;
    
    		cp = el->el_line.buffer;
    		while ((num = (*el->el_read->read_char)(el, &wc)) == 1) {
    			*cp = wc;
    			/* make sure there is space for next character */
    			if (cp + 1 >= el->el_line.limit) {
    				idx = (cp - el->el_line.buffer);
    				if (!ch_enlargebufs(el, 2))
    					break;
    				cp = &el->el_line.buffer[idx];
    			}
    			cp++;
    			if (el->el_flags & UNBUFFERED)
    				break;
    			if (cp[-1] == '\r' || cp[-1] == '\n')
    				break;
    		}
    		if (num == -1 && errno == EINTR)
    			cp = el->el_line.buffer;
    		goto noedit;
    	}
    
    
    #ifdef FIONREAD
    	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
    		int chrs = 0;
    
    		(void) ioctl(el->el_infd, FIONREAD, &chrs);
    		if (chrs == 0) {
    			if (tty_rawmode(el) < 0) {
    				errno = 0;
    				*nread = 0;
    				return NULL;
    			}
    		}
    	}
    #endif /* FIONREAD */
    
    	if ((el->el_flags & UNBUFFERED) == 0)
    		read_prepare(el);
    
    	if (el->el_flags & EDIT_DISABLED) {
    		size_t idx;
    
    		if ((el->el_flags & UNBUFFERED) == 0)
    			cp = el->el_line.buffer;
    		else
    			cp = el->el_line.lastchar;
    
    		terminal__flush(el);
    
    		while ((num = (*el->el_read->read_char)(el, &wc)) == 1) {
    			*cp = wc;
    			/* make sure there is space next character */
    			if (cp + 1 >= el->el_line.limit) {
    				idx = (cp - el->el_line.buffer);
    				if (!ch_enlargebufs(el, 2))
    					break;
    				cp = &el->el_line.buffer[idx];
    			}
    			cp++;
    			crlf = cp[-1] == '\r' || cp[-1] == '\n';
    			if (el->el_flags & UNBUFFERED)
    				break;
    			if (crlf)
    				break;
    		}
    		if (num == -1 && errno == EINTR)
    			cp = el->el_line.buffer;
    		goto noedit;
    	}
    
    	for (num = -1; num == -1;) {  /* while still editing this line */
    		/* if EOF or error */
    		if (read_getcmd(el, &cmdnum, &ch) == -1)
    			break;
    		if ((int)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
    			continue;	/* try again */
    		/* now do the real command */
    		/* vi redo needs these way down the levels... */
    		el->el_state.thiscmd = cmdnum;
    		el->el_state.thisch = ch;
    		if (el->el_map.type == MAP_VI &&
    		    el->el_map.current == el->el_map.key &&
    		    el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
    			if (cmdnum == VI_DELETE_PREV_CHAR &&
    			    el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
    			    && iswprint(el->el_chared.c_redo.pos[-1]))
    				el->el_chared.c_redo.pos--;
    			else
    				*el->el_chared.c_redo.pos++ = ch;
    		}
    		retval = (*el->el_map.func[cmdnum]) (el, ch);
    
    		/* save the last command here */
    		el->el_state.lastcmd = cmdnum;
    
    		/* use any return value */
    		switch (retval) {
    		case CC_CURSOR:
    			re_refresh_cursor(el);
    			break;
    
    		case CC_REDISPLAY:
    			re_clear_lines(el);
    			re_clear_display(el);
    			/* FALLTHROUGH */
    
    		case CC_REFRESH:
    			re_refresh(el);
    			break;
    
    		case CC_REFRESH_BEEP:
    			re_refresh(el);
    			terminal_beep(el);
    			break;
    
    		case CC_NORM:	/* normal char */
    			break;
    
    		case CC_ARGHACK:	/* Suggested by Rich Salz */
    			/* <rsalz@pineapple.bbn.com> */
    			continue;	/* keep going... */
    
    		case CC_EOF:	/* end of file typed */
    			if ((el->el_flags & UNBUFFERED) == 0)
    				num = 0;
    			else if (num == -1) {
    				*el->el_line.lastchar++ = CONTROL('d');
    				el->el_line.cursor = el->el_line.lastchar;
    				num = 1;
    			}
    			break;
    
    		case CC_NEWLINE:	/* normal end of line */
    			num = (int)(el->el_line.lastchar - el->el_line.buffer);
    			break;
    
    		case CC_FATAL:	/* fatal error, reset to known state */
    			/* put (real) cursor in a known place */
    			re_clear_display(el);	/* reset the display stuff */
    			ch_reset(el);	/* reset the input pointers */
    			read_clearmacros(&el->el_read->macros);
    			re_refresh(el); /* print the prompt again */
    			break;
    
    		case CC_ERROR:
    		default:	/* functions we don't know about */
    			terminal_beep(el);
    			terminal__flush(el);
    			break;
    		}
    		el->el_state.argument = 1;
    		el->el_state.doingarg = 0;
    		el->el_chared.c_vcmd.action = NOP;
    		if (el->el_flags & UNBUFFERED)
    			break;
    	}
    
    	terminal__flush(el);		/* flush any buffered output */
    	/* make sure the tty is set up correctly */
    	if ((el->el_flags & UNBUFFERED) == 0) {
    		read_finish(el);
    		*nread = num != -1 ? num : 0;
    	} else {
    		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);
    	}
    	goto done;
    noedit:
    	el->el_line.cursor = el->el_line.lastchar = cp;
    	*cp = '\0';
    	*nread = (int)(el->el_line.cursor - el->el_line.buffer);
    done:
    	if (*nread == 0) {
    		if (num == -1) {
    			*nread = -1;
    			if (el->el_read->read_errno)
    				errno = el->el_read->read_errno;
    		}
    		return NULL;
    	} else
    		return el->el_line.buffer;
    }