1 /* Input handling for G++.
2 Copyright (C) 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /* G++ needs to do enough saving and re-parsing of text that it is
23 necessary to abandon the simple FILE* model and use a mechanism where
24 we can pre-empt one input stream with another derived from saved text;
25 we may need to do this arbitrarily often, and cannot depend on having
26 the GNU library available, so FILE objects just don't cut it.
28 This file is written as a separate module, but can be included by
29 lex.c for very minor efficiency gains (primarily in function
40 /* current position, when reading as input */
42 /* linked list maintenance */
43 struct input_source *next;
44 /* values to restore after reading all of current string */
47 struct pending_input *input;
51 static struct input_source *input, *free_inputs;
53 extern char *input_filename;
57 #define inline __inline__
63 extern unsigned char *yy_cur, *yy_lim;
64 extern int yy_get_token ();
65 #define GETC() (yy_cur < yy_lim ? *yy_cur++ : yy_get_token ())
67 #define GETC() getc (finput)
70 extern void feed_input PROTO((char *, int));
71 extern void put_input PROTO((int));
72 extern void put_back PROTO((int));
73 extern int getch PROTO((void));
74 extern int input_redirected PROTO((void));
76 static inline struct input_source * allocate_input PROTO((void));
77 static inline void free_input PROTO((struct input_source *));
78 static inline void end_input PROTO((void));
79 static inline int sub_getch PROTO((void));
81 static inline struct input_source *
84 struct input_source *inp;
88 free_inputs = inp->next;
92 inp = (struct input_source *) xmalloc (sizeof (struct input_source));
99 struct input_source *inp;
103 inp->next = free_inputs;
107 static int putback_char = -1;
109 /* Some of these external functions are declared inline in case this file
110 is included in lex.c. */
114 feed_input (str, len)
118 struct input_source *inp = allocate_input ();
120 /* This shouldn't be necessary. */
121 while (len && !str[len-1])
128 inp->filename = input_filename;
129 inp->lineno = lineno;
130 inp->input = save_pending_input ();
131 inp->putback_char = putback_char;
136 struct pending_input *to_be_restored; /* XXX */
137 extern int end_of_file;
142 struct input_source *inp = input;
146 input_filename = inp->filename;
147 lineno = inp->lineno;
148 /* Get interface/implementation back in sync. */
149 extract_interface_info ();
150 putback_char = inp->putback_char;
151 restore_pending_input (inp->input);
158 if (putback_char != -1)
160 int ch = putback_char;
166 if (input->offset >= input->length)
168 my_friendly_assert (putback_char == -1, 223);
170 if (input->offset - input->length < 64)
173 /* We must be stuck in an error-handling rule; give up. */
177 return (unsigned char)input->str[input->offset++];
189 my_friendly_assert (putback_char == -1, 224);
199 int ch = sub_getch ();
200 if (linemode && ch == '\n')