/* Input handling for G++. Copyright (C) 1992, 1993, 1994, 1995 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 lex.c for very minor efficiency gains (primarily in function inlining). */ #include #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 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; static inline int sub_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; { if (ch != EOF) { my_friendly_assert (putback_char == -1, 224); putback_char = ch; } } extern int linemode; int getch () { int ch = sub_getch (); if (linemode && ch == '\n') { put_back (ch); ch = EOF; } return ch; } inline int input_redirected () { return input != 0; }
