usr.bin/indent/lexi.c
/*	$NetBSD: lexi.c,v 1.13 2009/04/12 11:09:49 lukem Exp $	*/

/*
 * Copyright (c) 1980, 1993
 *	The Regents of the University of California.  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.
 * 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.
 */

/*
 * Copyright (c) 1976 Board of Trustees of the University of Illinois.
 * Copyright (c) 1985 Sun Microsystems, Inc.
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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 <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)lexi.c	8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: lexi.c,v 1.13 2009/04/12 11:09:49 lukem Exp $");
#endif
#endif				/* not lint */

/*
 * Here we have the token scanner for indent.  It scans off one token and puts
 * it in the global variable "token".  It returns a code, indicating the type
 * of token scanned.
 */

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include "indent_globs.h"
#include "indent_codes.h"

#define alphanum 1
#define opchar 3

struct templ {
	const char	*rwd;
	int		rwcode;
};

struct templ specials[1000] =
{
	{"switch", 1},
	{"case", 2},
	{"break", 0},
	{"struct", 3},
	{"union", 3},
	{"enum", 3},
	{"default", 2},
	{"int", 4},
	{"char", 4},
	{"float", 4},
	{"double", 4},
	{"long", 4},
	{"short", 4},
	{"typdef", 4},
	{"unsigned", 4},
	{"register", 4},
	{"static", 4},
	{"global", 4},
	{"extern", 4},
	{"void", 4},
	{"goto", 0},
	{"return", 0},
	{"if", 5},
	{"while", 5},
	{"for", 5},
	{"else", 6},
	{"do", 6},
	{"sizeof", 7},
	{0, 0}
};

char    chartype[128] =
{				/* this is used to facilitate the decision of
				 * what type (alphanumeric, operator) each
				 * character is */
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,
	0, 3, 0, 0, 1, 3, 3, 0,
	0, 0, 3, 3, 0, 3, 0, 3,
	1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 0, 0, 3, 3, 3, 3,
	0, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 0, 0, 0, 3, 1,
	0, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 0, 3, 0, 3, 0
};




int
lexi(void)
{
	int     unary_delim;	/* this is set to 1 if the current token
				 * 
				 * forces a following operator to be unary */
	static int last_code;	/* the last token type returned */
	static int l_struct;	/* set to 1 if the last token was 'struct' */
	int     code;		/* internal code to be returned */
	char    qchar;		/* the delimiter character for a string */

	e_token = s_token;	/* point to start of place to save token */
	unary_delim = false;
	ps.col_1 = ps.last_nl;	/* tell world that this token started in
				 * column 1 iff the last thing scanned was nl */
	ps.last_nl = false;

	while (*buf_ptr == ' ' || *buf_ptr == '\t') {	/* get rid of blanks */
		ps.col_1 = false;	/* leading blanks imply token is not
					 * in column 1 */
		if (++buf_ptr >= buf_end)
			fill_buffer();
	}

	/* Scan an alphanumeric token */
	if (chartype[(int) *buf_ptr] == alphanum ||
	    (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
		/*
		 * we have a character or number
		 */
		const char *j;	/* used for searching thru list of
				 * reserved words */
		struct templ *p;

		if (isdigit((unsigned char)*buf_ptr) ||
		    (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
			int     seendot = 0, seenexp = 0, seensfx = 0;
			if (*buf_ptr == '0' &&
			    (buf_ptr[1] == 'x' || buf_ptr[1] == 'X')) {
				*e_token++ = *buf_ptr++;
				*e_token++ = *buf_ptr++;
				while (isxdigit((unsigned char)*buf_ptr)) {
					CHECK_SIZE_TOKEN;
					*e_token++ = *buf_ptr++;
				}
			} else {
				while (1) {
					if (*buf_ptr == '.') {
						if (seendot)
							break;
						else
							seendot++;
					}
					CHECK_SIZE_TOKEN;
					*e_token++ = *buf_ptr++;
					if (!isdigit((unsigned char)*buf_ptr)
					&& *buf_ptr != '.') {
						if ((*buf_ptr != 'E'
						&& *buf_ptr != 'e') || seenexp)
							break;
						else {
							seenexp++;
							seendot++;
							CHECK_SIZE_TOKEN;
							*e_token++ = *buf_ptr++;
							if (*buf_ptr == '+' || *buf_ptr == '-')
								*e_token++ = *buf_ptr++;
						}
					}
				}
			}
			if (*buf_ptr == 'F' || *buf_ptr == 'f') {
				/* float constant */
				*e_token++ = *buf_ptr++;
			} else {
				/* integer constant */
				while (1) {
					if (!(seensfx & 1) &&
					    (*buf_ptr == 'U' ||
					     *buf_ptr == 'u')) {
						CHECK_SIZE_TOKEN;
						*e_token++ = *buf_ptr++;
						seensfx |= 1;
						continue;
					}
					if (!(seensfx & 2) &&
					    (*buf_ptr == 'L' ||
					     *buf_ptr == 'l')) {
						CHECK_SIZE_TOKEN;
						if (buf_ptr[1] == buf_ptr[0])
							*e_token++ = *buf_ptr++;
						*e_token++ = *buf_ptr++;
						seensfx |= 2;
						continue;
					}
					break;
				}
			}
		} else
			while (chartype[(int) *buf_ptr] == alphanum) {	/* copy it over */
				CHECK_SIZE_TOKEN;
				*e_token++ = *buf_ptr++;
				if (buf_ptr >= buf_end)
					fill_buffer();
			}
		*e_token++ = '\0';
		while (*buf_ptr == ' ' || *buf_ptr == '\t') {	/* get rid of blanks */
			if (++buf_ptr >= buf_end)
				fill_buffer();
		}
		ps.its_a_keyword = false;
		ps.sizeof_keyword = false;
		if (l_struct) {	/* if last token was 'struct', then this token
				 * should be treated as a declaration */
			l_struct = false;
			last_code = ident;
			ps.last_u_d = true;
			return (decl);
		}
		ps.last_u_d = false;	/* Operator after indentifier is
					 * binary */
		last_code = ident;	/* Remember that this is the code we
					 * will return */

		/*
		 * This loop will check if the token is a keyword.
		 */
		for (p = specials; (j = p->rwd) != 0; p++) {
			char   *pt = s_token;	/* point at scanned token */
			if (*j++ != *pt++ || *j++ != *pt++)
				continue;	/* This test depends on the
						 * fact that identifiers are
						 * always at least 1 character
						 * long (ie. the first two
						 * bytes of the identifier are
						 * always meaningful) */
			if (pt[-1] == 0)
				break;	/* If its a one-character identifier */
			while (*pt++ == *j)
				if (*j++ == 0)
					goto found_keyword;	/* I wish that C had a
								 * multi-level break... */
		}
		if (p->rwd) {	/* we have a keyword */
	found_keyword:
			ps.its_a_keyword = true;
			ps.last_u_d = true;
			switch (p->rwcode) {
			case 1:/* it is a switch */
				return (swstmt);
			case 2:/* a case or default */
				return (casestmt);

			case 3:/* a "struct" */
				if (ps.p_l_follow)
					break;	/* inside parens: cast */
				l_struct = true;

				/*
				 * Next time around, we will want to know that we have had a
				 * 'struct'
				 */
			case 4:/* one of the declaration keywords */
				if (ps.p_l_follow) {
					ps.cast_mask |= 1 << ps.p_l_follow;
					break;	/* inside parens: cast */
				}
				last_code = decl;
				return (decl);

			case 5:/* if, while, for */
				return (sp_paren);

			case 6:/* do, else */
				return (sp_nparen);

			case 7:
				ps.sizeof_keyword = true;
			default:	/* all others are treated like any
					 * other identifier */
				return (ident);
			}	/* end of switch */
		}		/* end of if (found_it) */
		if (*buf_ptr == '(' && ps.tos <= 1 && ps.ind_level == 0) {
			char   *tp = buf_ptr;
			while (tp < buf_end)
				if (*tp++ == ')' && (*tp == ';' || *tp == ','))
					goto not_proc;
			strncpy(ps.procname, token, sizeof ps.procname - 1);
			ps.in_parameter_declaration = 1;
			rparen_count = 1;
	not_proc:	;
		}
		/*
		 * The following hack attempts to guess whether or not the current
		 * token is in fact a declaration keyword -- one that has been
		 * typedefd
		 */
		if (((*buf_ptr == '*' && buf_ptr[1] != '=') ||
		    isalpha((unsigned char)*buf_ptr) || *buf_ptr == '_')
		    && !ps.p_l_follow
		    && !ps.block_init
		    && (ps.last_token == rparen || ps.last_token == semicolon ||
			ps.last_token == decl ||
			ps.last_token == lbrace || ps.last_token == rbrace)) {
			ps.its_a_keyword = true;
			ps.last_u_d = true;
			last_code = decl;
			return decl;
		}
		if (last_code == decl)	/* if this is a declared variable,
					 * then following sign is unary */
			ps.last_u_d = true;	/* will make "int a -1" work */
		last_code = ident;
		return (ident);	/* the ident is not in the list */
	}			/* end of procesing for alpanum character */
	/* Scan a non-alphanumeric token */
	*e_token++ = *buf_ptr;	/* if it is only a one-character token, it is
				 * moved here */
	*e_token = '\0';
	if (++buf_ptr >= buf_end)
		fill_buffer();

	switch (*token) {
	case '\n':
		unary_delim = ps.last_u_d;
		ps.last_nl = true;	/* remember that we just had a newline */
		code = (had_eof ? 0 : newline);

		/*
		 * if data has been exausted, the newline is a dummy, and we should
		 * return code to stop
		 */
		break;

	case '\'':		/* start of quoted character */
	case '"':		/* start of string */
		qchar = *token;
		if (troff) {
			e_token[-1] = '`';
			if (qchar == '"')
				*e_token++ = '`';
			e_token = chfont(&bodyf, &stringf, e_token);
		}
		do {		/* copy the string */
			while (1) {	/* move one character or
					 * [/<char>]<char> */
				if (*buf_ptr == '\n') {
					printf("%d: Unterminated literal\n", line_no);
					goto stop_lit;
				}
				CHECK_SIZE_TOKEN;	/* Only have to do this
							 * once in this loop,
							 * since CHECK_SIZE
							 * guarantees that there
							 * are at least 5
							 * entries left */
				*e_token = *buf_ptr++;
				if (buf_ptr >= buf_end)
					fill_buffer();
				if (*e_token == BACKSLASH) {	/* if escape, copy extra
								 * char */
					if (*buf_ptr == '\n')	/* check for escaped
								 * newline */
						++line_no;
					if (troff) {
						*++e_token = BACKSLASH;
						if (*buf_ptr == BACKSLASH)
							*++e_token = BACKSLASH;
					}
					*++e_token = *buf_ptr++;
					++e_token;	/* we must increment
							 * this again because we
							 * copied two chars */
					if (buf_ptr >= buf_end)
						fill_buffer();
				} else
					break;	/* we copied one character */
			}	/* end of while (1) */
		} while (*e_token++ != qchar);
		if (troff) {
			e_token = chfont(&stringf, &bodyf, e_token - 1);
			if (qchar == '"')
				*e_token++ = '\'';
		}
stop_lit:
		code = ident;
		break;

	case ('('):
	case ('['):
		unary_delim = true;
		code = lparen;
		break;

	case (')'):
	case (']'):
		code = rparen;
		break;

	case '#':
		unary_delim = ps.last_u_d;
		code = preesc;
		break;

	case '?':
		unary_delim = true;
		code = question;
		break;

	case (':'):
		code = colon;
		unary_delim = true;
		break;

	case (';'):
		unary_delim = true;
		code = semicolon;
		break;

	case ('{'):
		unary_delim = true;

		/*
		 * if (ps.in_or_st) ps.block_init = 1;
		 */
		/* ?	code = ps.block_init ? lparen : lbrace; */
		code = lbrace;
		break;

	case ('}'):
		unary_delim = true;
		/* ?	code = ps.block_init ? rparen : rbrace; */
		code = rbrace;
		break;

	case 014:		/* a form feed */
		unary_delim = ps.last_u_d;
		ps.last_nl = true;	/* remember this so we can set
					 * 'ps.col_1' right */
		code = form_feed;
		break;

	case (','):
		unary_delim = true;
		code = comma;
		break;

	case '.':
		unary_delim = false;
		code = period;
		break;

	case '-':
	case '+':		/* check for -, +, --, ++ */
		code = (ps.last_u_d ? unary_op : binary_op);
		unary_delim = true;

		if (*buf_ptr == token[0]) {
			/* check for doubled character */
			*e_token++ = *buf_ptr++;
			/* buffer overflow will be checked at end of loop */
			if (last_code == ident || last_code == rparen) {
				code = (ps.last_u_d ? unary_op : postop);
				/* check for following ++ or -- */
				unary_delim = false;
			}
		} else
			if (*buf_ptr == '=')
				/* check for operator += */
				*e_token++ = *buf_ptr++;
			else
				if (*buf_ptr == '>') {
					/* check for operator -> */
					*e_token++ = *buf_ptr++;
					if (!pointer_as_binop) {
						unary_delim = false;
						code = unary_op;
						ps.want_blank = false;
					}
				}
		break;		/* buffer overflow will be checked at end of
				 * switch */

	case '=':
		if (ps.in_or_st)
			ps.block_init = 1;
#ifdef undef
		if (chartype[*buf_ptr] == opchar) {	/* we have two char
							 * assignment */
			e_token[-1] = *buf_ptr++;
			if ((e_token[-1] == '<' || e_token[-1] == '>') && e_token[-1] == *buf_ptr)
				*e_token++ = *buf_ptr++;
			*e_token++ = '=';	/* Flip =+ to += */
			*e_token = 0;
		}
#else
		if (*buf_ptr == '=') {	/* == */
			*e_token++ = '=';	/* Flip =+ to += */
			buf_ptr++;
			*e_token = 0;
		}
#endif
		code = binary_op;
		unary_delim = true;
		break;
		/* can drop thru!!! */

	case '>':
	case '<':
	case '!':		/* ops like <, <<, <=, !=, etc */
		if (*buf_ptr == '>' || *buf_ptr == '<' || *buf_ptr == '=') {
			*e_token++ = *buf_ptr;
			if (++buf_ptr >= buf_end)
				fill_buffer();
		}
		if (*buf_ptr == '=')
			*e_token++ = *buf_ptr++;
		code = (ps.last_u_d ? unary_op : binary_op);
		unary_delim = true;
		break;

	default:
		if (token[0] == '/' && *buf_ptr == '*') {
			/* it is start of comment */
			*e_token++ = '*';

			if (++buf_ptr >= buf_end)
				fill_buffer();

			code = comment;
			unary_delim = ps.last_u_d;
			break;
		}
		while (*(e_token - 1) == *buf_ptr || *buf_ptr == '=') {
			/*
		         * handle ||, &&, etc, and also things as in int *****i
		         */
			*e_token++ = *buf_ptr;
			if (++buf_ptr >= buf_end)
				fill_buffer();
		}
		code = (ps.last_u_d ? unary_op : binary_op);
		unary_delim = true;


	}			/* end of switch */
	if (code != newline) {
		l_struct = false;
		last_code = code;
	}
	if (buf_ptr >= buf_end)	/* check for input buffer empty */
		fill_buffer();
	ps.last_u_d = unary_delim;
	*e_token = '\0';	/* null terminate the token */
	return (code);
}
/*
 * Add the given keyword to the keyword table, using val as the keyword type
 */
void
addkey(char *key, int val)
{
	struct templ *p = specials;
	while (p->rwd)
		if (p->rwd[0] == key[0] && strcmp(p->rwd, key) == 0)
			return;
		else
			p++;
	if (p >= specials + sizeof specials / sizeof specials[0])
		return;		/* For now, table overflows are silently
				 * ignored */
	p->rwd = key;
	p->rwcode = val;
	p[1].rwd = 0;
	p[1].rwcode = 0;
}
