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Diffstat (limited to 'gcc/cp/input.c')
| -rw-r--r-- | gcc/cp/input.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/gcc/cp/input.c b/gcc/cp/input.c new file mode 100644 index 00000000000..1252aed187a --- /dev/null +++ b/gcc/cp/input.c @@ -0,0 +1,184 @@ +/* Input handling for G++. + Copyright (C) 1992, 1993 Free Software Foundation, Inc. + Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing. + +This file is part of GNU CC. + +GNU CC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU CC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU CC; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* G++ needs to do enough saving and re-parsing of text that it is + necessary to abandon the simple FILE* model and use a mechanism where + we can pre-empt one input stream with another derived from saved text; + we may need to do this arbitrarily often, and cannot depend on having + the GNU library available, so FILE objects just don't cut it. + + This file is written as a separate module, but can be included by + cp-lex.c for very minor efficiency gains (primarily in function + inlining). */ + +#include <stdio.h> +#include "obstack.h" + +extern FILE *finput; + +struct pending_input *save_pending_input (); +void restore_pending_input (); + +struct input_source { + /* saved string */ + char *str; + int length; + /* current position, when reading as input */ + int offset; + /* obstack to free this input string from when finished, if any */ + struct obstack *obstack; + /* linked list maintenance */ + struct input_source *next; + /* values to restore after reading all of current string */ + char *filename; + int lineno; + struct pending_input *input; + int putback_char; +}; + +static struct input_source *input, *free_inputs; + +extern char *input_filename; +extern int lineno; + +#ifdef __GNUC__ +#define inline __inline__ +#else +#define inline +#endif + +static inline struct input_source * +allocate_input () +{ + struct input_source *inp; + if (free_inputs) + { + inp = free_inputs; + free_inputs = inp->next; + inp->next = 0; + return inp; + } + inp = (struct input_source *) xmalloc (sizeof (struct input_source)); + inp->next = 0; + inp->obstack = 0; + return inp; +} + +static inline void +free_input (inp) + struct input_source *inp; +{ + if (inp->obstack) + obstack_free (inp->obstack, inp->str); + inp->obstack = 0; + inp->str = 0; + inp->length = 0; + inp->next = free_inputs; + free_inputs = inp; +} + +static int putback_char = -1; + +/* Some of these external functions are declared inline in case this file + is included in cp-lex.c. */ + +inline +void +feed_input (str, len, delete) + char *str; + int len; + struct obstack *delete; +{ + struct input_source *inp = allocate_input (); + + /* This shouldn't be necessary. */ + while (len && !str[len-1]) + len--; + + inp->str = str; + inp->length = len; + inp->obstack = delete; + inp->offset = 0; + inp->next = input; + inp->filename = input_filename; + inp->lineno = lineno; + inp->input = save_pending_input (); + inp->putback_char = putback_char; + putback_char = -1; + input = inp; +} + +struct pending_input *to_be_restored; /* XXX */ +extern int end_of_file; + +int +getch () +{ + if (putback_char != -1) + { + int ch = putback_char; + putback_char = -1; + return ch; + } + if (input) + { + if (input->offset == input->length) + { + struct input_source *inp = input; + my_friendly_assert (putback_char == -1, 223); + to_be_restored = inp->input; + input->offset++; + return EOF; + } + else if (input->offset > input->length) + { + struct input_source *inp = input; + + end_of_file = 0; + input = inp->next; + input_filename = inp->filename; + lineno = inp->lineno; + /* Get interface/implementation back in sync. */ + extract_interface_info (); + putback_char = inp->putback_char; + free_input (inp); + return getch (); + } + if (input) + return input->str[input->offset++]; + } + return getc (finput); +} + +inline +void +put_back (ch) + int ch; +{ + my_friendly_assert (putback_char == -1, 224); + putback_char = ch; +} + +inline +int +input_redirected () +{ + return input != 0; +} |