Initial revision

1 files changed, 248 insertions, 0 deletions

diff --git a/gas/input-file.c b/gas/input-file.c
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--- /dev/null
+++ b/gas/input-file.c
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+/* 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 */