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Diffstat (limited to 'gas/input-file.c')
| -rw-r--r-- | gas/input-file.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/gas/input-file.c b/gas/input-file.c new file mode 100644 index 0000000..c63f7c9 --- /dev/null +++ b/gas/input-file.c @@ -0,0 +1,248 @@ +/* input_file.c - Deal with Input Files - + Copyright (C) 1987, 1990, 1991, 1992, 1998 Free Software Foundation, Inc. + + This file is part of GAS, the GNU Assembler. + + GAS 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. + + GAS 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 GAS; see the file COPYING. If not, write to + the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* + * Confines all details of reading source bytes to this module. + * All O/S specific crocks should live here. + * What we lose in "efficiency" we gain in modularity. + * Note we don't need to #include the "as.h" file. No common coupling! + */ + +#include <stdio.h> +#include <string.h> + +#include "as.h" +#include "input-file.h" + +static int input_file_get PARAMS ((char **)); + +/* This variable is non-zero if the file currently being read should be + preprocessed by app. It is zero if the file can be read straight in. + */ +int preprocess = 0; + +/* + * This code opens a file, then delivers BUFFER_SIZE character + * chunks of the file on demand. + * BUFFER_SIZE is supposed to be a number chosen for speed. + * The caller only asks once what BUFFER_SIZE is, and asks before + * the nature of the input files (if any) is known. + */ + +#define BUFFER_SIZE (32 * 1024) + +/* + * We use static data: the data area is not sharable. + */ + +static FILE *f_in; +static char *file_name; + +/* Struct for saving the state of this module for file includes. */ +struct saved_file + { + FILE *f_in; + char *file_name; + int preprocess; + char *app_save; + }; + +/* These hooks accomodate most operating systems. */ + +void +input_file_begin () +{ + f_in = (FILE *) 0; +} + +void +input_file_end () +{ +} + +/* Return BUFFER_SIZE. */ +unsigned int +input_file_buffer_size () +{ + return (BUFFER_SIZE); +} + +int +input_file_is_open () +{ + return f_in != (FILE *) 0; +} + +/* Push the state of our input, returning a pointer to saved info that + can be restored with input_file_pop (). */ +char * +input_file_push () +{ + register struct saved_file *saved; + + saved = (struct saved_file *) xmalloc (sizeof *saved); + + saved->f_in = f_in; + saved->file_name = file_name; + saved->preprocess = preprocess; + if (preprocess) + saved->app_save = app_push (); + + input_file_begin (); /* Initialize for new file */ + + return (char *) saved; +} + +void +input_file_pop (arg) + char *arg; +{ + register struct saved_file *saved = (struct saved_file *) arg; + + input_file_end (); /* Close out old file */ + + f_in = saved->f_in; + file_name = saved->file_name; + preprocess = saved->preprocess; + if (preprocess) + app_pop (saved->app_save); + + free (arg); +} + +void +input_file_open (filename, pre) + char *filename; /* "" means use stdin. Must not be 0. */ + int pre; +{ + int c; + char buf[80]; + + preprocess = pre; + + assert (filename != 0); /* Filename may not be NULL. */ + if (filename[0]) + { /* We have a file name. Suck it and see. */ + f_in = fopen (filename, "r"); + file_name = filename; + } + else + { /* use stdin for the input file. */ + f_in = stdin; + file_name = _("{standard input}"); /* For error messages. */ + } + if (f_in == (FILE *) 0) + { + as_bad (_("Can't open %s for reading."), file_name); + as_perror ("%s", file_name); + return; + } + + c = getc (f_in); + if (c == '#') + { /* Begins with comment, may not want to preprocess */ + c = getc (f_in); + if (c == 'N') + { + fgets (buf, 80, f_in); + if (!strcmp (buf, "O_APP\n")) + preprocess = 0; + if (!strchr (buf, '\n')) + ungetc ('#', f_in); /* It was longer */ + else + ungetc ('\n', f_in); + } + else if (c == '\n') + ungetc ('\n', f_in); + else + ungetc ('#', f_in); + } + else + ungetc (c, f_in); +} + +/* Close input file. */ +void +input_file_close () +{ + if (f_in != NULL) + { + fclose (f_in); + } /* don't close a null file pointer */ + f_in = 0; +} /* input_file_close() */ + +/* This function is passed to do_scrub_chars. */ + +static int +input_file_get (from) + char **from; +{ + static char buf[BUFFER_SIZE]; + int size; + + size = fread (buf, sizeof (char), sizeof buf, f_in); + if (size < 0) + { + as_perror (_("Can't read from %s"), file_name); + size = 0; + } + *from = buf; + return size; +} + +/* Read a buffer from the input file. */ + +char * +input_file_give_next_buffer (where) + char *where; /* Where to place 1st character of new buffer. */ +{ + char *return_value; /* -> Last char of what we read, + 1. */ + register int size; + + if (f_in == (FILE *) 0) + return 0; + /* + * fflush (stdin); could be done here if you want to synchronise + * stdin and stdout, for the case where our input file is stdin. + * Since the assembler shouldn't do any output to stdout, we + * don't bother to synch output and input. + */ + if (preprocess) + size = do_scrub_chars (input_file_get, where, BUFFER_SIZE); + else + size = fread (where, sizeof (char), BUFFER_SIZE, f_in); + if (size < 0) + { + as_perror (_("Can't read from %s"), file_name); + size = 0; + } + if (size) + return_value = where + size; + else + { + if (fclose (f_in)) + as_perror (_("Can't close %s"), file_name); + f_in = (FILE *) 0; + return_value = 0; + } + return (return_value); +} + +/* end of input-file.c */ |