/* input_file.c - Deal with Input Files - Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 98, 1999 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 *, int)); /* 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 (buf, buflen) char *buf; int buflen; { int size; size = fread (buf, sizeof (char), buflen, f_in); if (size < 0) { as_perror (_("Can't read from %s"), file_name); size = 0; } 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 */