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__
62 extern void feed_input PROTO((char *, int));
63 extern void put_input PROTO((int));
64 extern void put_back PROTO((int));
65 extern int getch PROTO((void));
66 extern int input_redirected PROTO((void));
68 static inline struct input_source * allocate_input PROTO((void));
69 static inline void free_input PROTO((struct input_source *));
70 static inline void end_input PROTO((void));
71 static inline int sub_getch PROTO((void));
73 static inline struct input_source *
76 struct input_source *inp;
80 free_inputs = inp->next;
84 inp = (struct input_source *) xmalloc (sizeof (struct input_source));
91 struct input_source *inp;
95 inp->next = free_inputs;
99 static int putback_char = -1;
101 /* Some of these external functions are declared inline in case this file
102 is included in lex.c. */
106 feed_input (str, len)
110 struct input_source *inp = allocate_input ();
112 /* This shouldn't be necessary. */
113 while (len && !str[len-1])
120 inp->filename = input_filename;
121 inp->lineno = lineno;
122 inp->input = save_pending_input ();
123 inp->putback_char = putback_char;
128 struct pending_input *to_be_restored; /* XXX */
129 extern int end_of_file;
134 struct input_source *inp = input;
138 input_filename = inp->filename;
139 lineno = inp->lineno;
140 /* Get interface/implementation back in sync. */
141 extract_interface_info ();
142 putback_char = inp->putback_char;
143 restore_pending_input (inp->input);
150 if (putback_char != -1)
152 int ch = putback_char;
158 if (input->offset >= input->length)
160 my_friendly_assert (putback_char == -1, 223);
162 if (input->offset - input->length < 64)
165 /* We must be stuck in an error-handling rule; give up. */
169 return (unsigned char)input->str[input->offset++];
171 return getc (finput);
181 my_friendly_assert (putback_char == -1, 224);
191 int ch = sub_getch ();
192 if (linemode && ch == '\n')