input-scrub.c

基于4个mips核的noc设计

/* input_scrub.c - Break up input buffers into whole numbers of lines.
   Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   2000
   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.  */

#include <errno.h>		/* Need this to make errno declaration right */
#include "as.h"
#include "input-file.h"
#include "sb.h"
#include "listing.h"

/*
 * O/S independent module to supply buffers of sanitised source code
 * to rest of assembler.  We get sanitised input data of arbitrary length.
 * We break these buffers on line boundaries, recombine pieces that
 * were broken across buffers, and return a buffer of full lines to
 * the caller.
 * The last partial line begins the next buffer we build and return to caller.
 * The buffer returned to caller is preceeded by BEFORE_STRING and followed
 * by AFTER_STRING, as sentinels. The last character before AFTER_STRING
 * is a newline.
 * Also looks after line numbers, for e.g. error messages.
 */

/*
 * We don't care how filthy our buffers are, but our callers assume
 * that the following sanitation has already been done.
 *
 * No comments, reduce a comment to a space.
 * Reduce a tab to a space unless it is 1st char of line.
 * All multiple tabs and spaces collapsed into 1 char. Tab only
 *   legal if 1st char of line.
 * # line file statements converted to .line x;.file y; statements.
 * Escaped newlines at end of line: remove them but add as many newlines
 *   to end of statement as you removed in the middle, to synch line numbers.
 */

#define BEFORE_STRING ("\n")
#define AFTER_STRING ("\0")	/* memcpy of 0 chars might choke.  */
#define BEFORE_SIZE (1)
#define AFTER_SIZE  (1)

static char *buffer_start;	/*->1st char of full buffer area.  */
static char *partial_where;	/*->after last full line in buffer.  */
static int partial_size;	/* >=0. Number of chars in partial line in buffer.  */

/* Because we need AFTER_STRING just after last full line, it clobbers
   1st part of partial line. So we preserve 1st part of partial line
   here.  */
static char save_source[AFTER_SIZE];

/* What is the largest size buffer that input_file_give_next_buffer()
   could return to us?  */
static unsigned int buffer_length;

/* The index into an sb structure we are reading from.  -1 if none.  */
static int sb_index = -1;

/* If we are reading from an sb structure, this is it.  */
static sb from_sb;

/* Should we do a conditional check on from_sb? */
static int from_sb_is_expansion = 1;

/* The number of nested sb structures we have included.  */
int macro_nest;

/* We can have more than one source file open at once, though the info for all
   but the latest one are saved off in a struct input_save.  These files remain
   open, so we are limited by the number of open files allowed by the
   underlying OS. We may also sequentially read more than one source file in an
   assembly.  */

/* We must track the physical file and line number for error messages. We also
   track a "logical" file and line number corresponding to (C?)  compiler
   source line numbers.  Whenever we open a file we must fill in
   physical_input_file. So if it is NULL we have not opened any files yet.  */

static char *physical_input_file;
static char *logical_input_file;

typedef unsigned int line_numberT;	/* 1-origin line number in a source file.  */
/* A line ends in '\n' or eof.  */

static line_numberT physical_input_line;
static int logical_input_line;

/* Struct used to save the state of the input handler during include files */
struct input_save {
  char *              buffer_start;
  char *              partial_where;
  int                 partial_size;
  char                save_source[AFTER_SIZE];
  unsigned int        buffer_length;
  char *              physical_input_file;
  char *              logical_input_file;
  line_numberT        physical_input_line;
  int                 logical_input_line;
  int                 sb_index;
  sb                  from_sb;
  int                 from_sb_is_expansion; /* Should we do a conditional check?  */
  struct input_save * next_saved_file;	/* Chain of input_saves.  */
  char *              input_file_save;	/* Saved state of input routines.  */
  char *              saved_position;	/* Caller's saved position in buf.  */
};

static struct input_save *input_scrub_push PARAMS ((char *saved_position));
static char *input_scrub_pop PARAMS ((struct input_save *arg));
static void as_1_char PARAMS ((unsigned int c, FILE * stream));

/* Saved information about the file that .include'd this one.  When we hit EOF,
   we automatically pop to that file.  */

static struct input_save *next_saved_file;

/* Push the state of input reading and scrubbing so that we can #include.
   The return value is a 'void *' (fudged for old compilers) to a save
   area, which can be restored by passing it to input_scrub_pop().  */

static struct input_save *
input_scrub_push (saved_position)
     char *saved_position;
{
  register struct input_save *saved;

  saved = (struct input_save *) xmalloc (sizeof *saved);

  saved->saved_position = saved_position;
  saved->buffer_start = buffer_start;
  saved->partial_where = partial_where;
  saved->partial_size = partial_size;
  saved->buffer_length = buffer_length;
  saved->physical_input_file = physical_input_file;
  saved->logical_input_file = logical_input_file;
  saved->physical_input_line = physical_input_line;
  saved->logical_input_line = logical_input_line;
  saved->sb_index = sb_index;
  saved->from_sb = from_sb;
  saved->from_sb_is_expansion = from_sb_is_expansion;
  memcpy (saved->save_source, save_source, sizeof (save_source));
  saved->next_saved_file = next_saved_file;
  saved->input_file_save = input_file_push ();

  input_file_begin ();		/* Reinitialize! */
  logical_input_line = -1;
  logical_input_file = (char *) NULL;
  buffer_length = input_file_buffer_size ();
  sb_index = -1;

  buffer_start = xmalloc ((BEFORE_SIZE + buffer_length + buffer_length + AFTER_SIZE));
  memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);

  return saved;
}

static char *
input_scrub_pop (saved)
     struct input_save *saved;
{
  char *saved_position;

  input_scrub_end ();		/* Finish off old buffer */

  input_file_pop (saved->input_file_save);
  saved_position = saved->saved_position;
  buffer_start = saved->buffer_start;
  buffer_length = saved->buffer_length;
  physical_input_file = saved->physical_input_file;
  logical_input_file = saved->logical_input_file;
  physical_input_line = saved->physical_input_line;
  logical_input_line = saved->logical_input_line;
  sb_index = saved->sb_index;
  from_sb = saved->from_sb;
  from_sb_is_expansion = saved->from_sb_is_expansion;
  partial_where = saved->partial_where;
  partial_size = saved->partial_size;
  next_saved_file = saved->next_saved_file;
  memcpy (save_source, saved->save_source, sizeof (save_source));

  free (saved);
  return saved_position;
}

void
input_scrub_begin ()
{
  know (strlen (BEFORE_STRING) == BEFORE_SIZE);
  know (strlen (AFTER_STRING) == AFTER_SIZE
	|| (AFTER_STRING[0] == '\0' && AFTER_SIZE == 1));

  input_file_begin ();

  buffer_length = input_file_buffer_size ();

  buffer_start = xmalloc ((BEFORE_SIZE + buffer_length + buffer_length + AFTER_SIZE));
  memcpy (buffer_start, BEFORE_STRING, (int) BEFORE_SIZE);

  /* Line number things.  */
  logical_input_line = -1;
  logical_input_file = (char *) NULL;
  physical_input_file = NULL;	/* No file read yet.  */
  next_saved_file = NULL;	/* At EOF, don't pop to any other file */
  do_scrub_begin (flag_m68k_mri);
}

void
input_scrub_end ()
{
  if (buffer_start)
    {
      free (buffer_start);
      buffer_start = 0;
      input_file_end ();
    }
}

/* Start reading input from a new file.
   Return start of caller's part of buffer.  */

char *
input_scrub_new_file (filename)
     char *filename;
{
  input_file_open (filename, !flag_no_comments);
  physical_input_file = filename[0] ? filename : _("{standard input}");
  physical_input_line = 0;

  partial_size = 0;
  return (buffer_start + BEFORE_SIZE);
}

/* Include a file from the current file.  Save our state, cause it to
   be restored on EOF, and begin handling a new file.  Same result as
   input_scrub_new_file.  */

char *
input_scrub_include_file (filename, position)
     char *filename;
     char *position;
{
  next_saved_file = input_scrub_push (position);
  return input_scrub_new_file (filename);
}

/* Start getting input from an sb structure.  This is used when
   expanding a macro.  */

void