input-file.c

早期freebsd实现

/*-
 * This code is derived from software copyrighted by the Free Software
 * Foundation.
 *
 * Modified 1991 by Donn Seeley at UUNET Technologies, Inc.
 */

#ifndef lint
static char sccsid[] = "@(#)input-file.c	6.2 (Berkeley) 5/8/91";
#endif /* not lint */

/* input_file.c - Deal with Input Files -
   Copyright (C) 1987 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, 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!
 */

#define NDEBUG		/* JF remove asserts */

#ifdef USG
#define index strchr
/* JF:  What's the difference between _IOLBF and _IOFBF ? */
#define setbuffer(stream, buf, size) setvbuf((stream), (buf), _IOFBF, (size))
#endif

#include <stdio.h>
#include <assert.h>
/* #include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/wait.h> */

/* #include "style.h" */
#include "input-file.h"

/* 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;

void	as_perror();

/*
 * 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)

static char in_buf[BUFFER_SIZE];

/*
 * We use static data: the data area is not sharable.
 */

FILE *f_in;	/* JF do things the RIGHT way */
/* static JF remove static so app.c can use file_name */
char *	file_name;

/* These hooks accomodate most operating systems. */

void
input_file_begin ()
{
  /* file_handle = -1; */
  f_in = (FILE *)0;
}

void
input_file_end ()
{
}

int				/* Return BUFFER_SIZE. */
input_file_buffer_size ()
{
  return (BUFFER_SIZE);
}

int
input_file_is_open ()
{
  /* return (file_handle >= 0); */
  return f_in!=(FILE *)0;
}

#ifdef DONTDEF		/* JF save old version in case we need it */
void
input_file_open (filename, preprocess, debugging)
     char *	filename;	/* "" means use stdin. Must not be 0. */
     int	preprocess;	/* TRUE if needs app. */
     int	debugging;	/* TRUE if we are debugging assembler. */
{
  assert( filename != 0 );	/* Filename may not be NULL. */
  if (filename [0])
    {				/* We have a file name. Suck it and see. */
      file_handle = open (filename, O_RDONLY, 0);
      file_name = filename;
    }
  else
    {				/* use stdin for the input file. */
      file_handle = fileno (stdin);
      file_name = "{standard input}"; /* For error messages. */
    }
  if (file_handle < 0)
      as_perror ("Can't open %s for reading", file_name);
  if ( preprocess )
    {
/*
 * This code was written in haste for a frobbed BSD 4.2.
 * I have a flight to catch: will someone please do proper
 * error checks? - Dean.
 */
      int	pid;
      char temporary_file_name [12];
      int	fd;
      union wait	status;
      char	*mktemp();

      (void)strcpy (temporary_file_name, "#appXXXXXX");
      (void)mktemp (temporary_file_name);
      pid = vfork ();
      if (pid == -1)
	{
	  as_perror ("Vfork failed", file_name);
	  _exit (144);
	}
      if (pid == 0)
	{
	  (void)dup2 (file_handle, fileno(stdin));
	  fd = open (temporary_file_name, O_WRONLY + O_TRUNC + O_CREAT, 0666);
	  if (fd == -1)
	    {
	      (void)write(2,"Can't open temporary\n",21);
	      _exit (99);
	    }
	  (void)dup2 (fd, fileno(stdout));
/* JF for testing #define PREPROCESSOR "/lib/app" */
#define PREPROCESSOR "./app"
	  execl (PREPROCESSOR, PREPROCESSOR, 0);
	  execl ("app","app",0);
	  (void)write(2,"Exec of app failed.  Get help.\n",31);
	  (void)unlink(temporary_file_name);
	  _exit (11);
	}
      (void)wait (& status);
      if (status.w_status & 0xFF00)		/* JF was 0xF000, was wrong */
	{
	  file_handle = -1;
	  as_warn( "Can't preprocess file \"%s\", status = %xx", file_name, status.w_status );
	}
      else
	{
	  file_handle = open (temporary_file_name, O_RDONLY, 0);
	  if ( ! debugging && unlink(temporary_file_name))
	    as_perror ("Can't delete temp file %s", temporary_file_name);
	}
      if (file_handle == -1)
	  as_perror ("Can't retrieve temp file %s", temporary_file_name);
    }
}
#else

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_perror ("Can't open %s for reading", file_name);
		return;
	}
#ifndef VMS
	setbuffer(f_in,in_buf,BUFFER_SIZE);
#endif /* VMS */
	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(!index(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);

#ifdef DONTDEF
	if ( preprocess ) {
		char temporary_file_name [17];
		char	*mktemp();
		FILE	*f_out;

		(void)strcpy (temporary_file_name, "/tmp/#appXXXXXX");
		(void)mktemp (temporary_file_name);
		f_out=fopen(temporary_file_name,"w+");
		if(f_out==(FILE *)0)
			as_perror("Can't open temp file %s",temporary_file_name);

			/* JF this will have to be moved on any system that
			   does not support removal of open files.  */
		(void)unlink(temporary_file_name);/* JF do it NOW */
		do_scrub(f_in,f_out);
		(void)fclose(f_in);	/* All done with it */
		(void)rewind(f_out);
		f_in=f_out;
	}
#endif
}
#endif

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.
       */
  /* size = read (file_handle, where, BUFFER_SIZE); */
  if(preprocess) {
	char *p;
	int n;
	int ch;
	extern FILE *scrub_file;
	int scrub_from_file();
	void scrub_to_file();
	int do_scrub_next_char();

	scrub_file=f_in;
	for(p=where,n=BUFFER_SIZE;n;--n) {
		ch=do_scrub_next_char(scrub_from_file,scrub_to_file);
		if(ch==EOF)
			break;
		*p++=ch;
	}
	size=BUFFER_SIZE-n;
  } 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: input_file.c */