1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5*                      and is licensed under the                       *
6*                 Eclipse Public License, Version 1.0                  *
7*                    by AT&T Intellectual Property                     *
8*                                                                      *
9*                A copy of the License is available at                 *
10*          http://www.eclipse.org/org/documents/epl-v10.html           *
11*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
12*                                                                      *
13*              Information and Software Systems Research               *
14*                            AT&T Research                             *
15*                           Florham Park NJ                            *
16*                                                                      *
17*                 Glenn Fowler <gsf@research.att.com>                  *
18*                  David Korn <dgk@research.att.com>                   *
19*                   Phong Vo <kpv@research.att.com>                    *
20*                                                                      *
21***********************************************************************/
22#pragma prototyped
23/*
24 * Glenn Fowler
25 * AT&T Research
26 *
27 * return an Sfio_t* to a file or string that
28 *
29 *	splices \\n to single lines
30 *	checks for "..." and '...' spanning newlines
31 *	drops #...\n comments
32 *
33 * if <arg> is a file and first line matches
34 *	#!!! <level> <message> !!!
35 * then error(<lev>,"%s: %s",<arg>,<msg>) called
36 *
37 * NOTE: seek disabled and string disciplines cannot be composed
38 *	 quoted \n translated to \r
39 */
40
41#include <ast.h>
42#include <error.h>
43#include <tok.h>
44
45typedef struct
46{
47	Sfdisc_t	disc;
48	Sfio_t*		sp;
49	int		quote;
50	int*		line;
51} Splice_t;
52
53/*
54 * the splicer
55 */
56
57static int
58spliceline(Sfio_t* s, int op, void* val, Sfdisc_t* ad)
59{
60	Splice_t*	d = (Splice_t*)ad;
61	register char*	b;
62	register int	c;
63	register int	n;
64	register int	q;
65	register int	j;
66	register char*	e;
67	char*		buf;
68
69	NoP(val);
70	switch (op)
71	{
72	case SF_CLOSING:
73		sfclose(d->sp);
74		return 0;
75	case SF_DPOP:
76		free(d);
77		return 0;
78	case SF_READ:
79		do
80		{
81			if (!(buf = sfgetr(d->sp, '\n', 0)) && !(buf = sfgetr(d->sp, '\n', -1)))
82				return 0;
83			n = sfvalue(d->sp);
84			q = d->quote;
85			j = 0;
86			(*d->line)++;
87			if (n > 1 && buf[n - 2] == '\\')
88			{
89				j = 1;
90				n -= 2;
91				if (q == '#')
92				{
93					n = 0;
94					continue;
95				}
96			}
97			else if (q == '#')
98			{
99				q = 0;
100				n = 0;
101				continue;
102			}
103			if (n > 0)
104			{
105				e = (b = buf) + n;
106				while (b < e)
107				{
108					if ((c = *b++) == '\\')
109						b++;
110					else if (c == q)
111						q = 0;
112					else if (!q)
113					{
114						if (c == '\'' || c == '"')
115							q = c;
116						else if (c == '#' && (b == (buf + 1) || (c = *(b - 2)) == ' ' || c == '\t'))
117						{
118							if (buf[n - 1] != '\n')
119							{
120								q = '#';
121								n = b - buf - 2;
122							}
123							else if (n = b - buf - 1)
124								buf[n - 1] = '\n';
125							break;
126						}
127					}
128				}
129				if (n > 0)
130				{
131					if (!j && buf[n - 1] != '\n' && (s->_flags & SF_STRING))
132						buf[n++] = '\n';
133					if (q && buf[n - 1] == '\n')
134						buf[n - 1] = '\r';
135				}
136			}
137		} while (n <= 0);
138		sfsetbuf(s, buf, n);
139		d->quote = q;
140		return 1;
141	default:
142		return 0;
143	}
144}
145
146/*
147 * open a stream to parse lines
148 *
149 *	flags: 0		arg: open Sfio_t*
150 *	flags: SF_READ		arg: file name
151 *	flags: SF_STRING	arg: null terminated char*
152 *
153 * if line!=0 then it points to a line count that starts at 0
154 * and is incremented for each input line
155 */
156
157Sfio_t*
158tokline(const char* arg, int flags, int* line)
159{
160	Sfio_t*		f;
161	Sfio_t*		s;
162	Splice_t*	d;
163	char*		p;
164	char*		e;
165
166	static int	hidden;
167
168	if (!(d = newof(0, Splice_t, 1, 0)))
169		return 0;
170	if (!(s = sfopen(NiL, NiL, "s")))
171	{
172		free(d);
173		return 0;
174	}
175	if (!(flags & (SF_STRING|SF_READ)))
176		f = (Sfio_t*)arg;
177	else if (!(f = sfopen(NiL, arg, (flags & SF_STRING) ? "s" : "r")))
178	{
179		free(d);
180		sfclose(s);
181		return 0;
182	}
183	else if ((p = sfreserve(f, 0, 0)) && sfvalue(f) > 11 && strmatch(p, "#!!! +([-0-9]) *([!\n]) !!!\n*") && (e = strchr(p, '\n')))
184	{
185		flags = strtol(p + 5, &p, 10);
186		error(flags, "%s:%-.*s", arg, e - p - 4, p);
187	}
188	d->disc.exceptf = spliceline;
189	d->sp = f;
190	*(d->line = line ? line : &hidden) = 0;
191	sfdisc(s, (Sfdisc_t*)d);
192	return s;
193}
194