app.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 1,329 行 · 第 1/3 页

/* This is the Assembler Pre-Processor
   Copyright 1987, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   1999, 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.  */

/* Modified by Allen Wirfs-Brock, Instantiations Inc 2/90 */
/* App, the assembler pre-processor.  This pre-processor strips out excess
   spaces, turns single-quoted characters into a decimal constant, and turns
   # <number> <filename> <garbage> into a .line <number>\n.file <filename>
   pair.  This needs better error-handling.  */

#include <stdio.h>
#include "as.h"			/* For BAD_CASE() only */

#if (__STDC__ != 1)
#ifndef const
#define const  /* empty */
#endif
#endif

#ifdef TC_M68K
/* Whether we are scrubbing in m68k MRI mode.  This is different from
   flag_m68k_mri, because the two flags will be affected by the .mri
   pseudo-op at different times.  */
static int scrub_m68k_mri;
#else
#define scrub_m68k_mri 0
#endif

/* The pseudo-op which switches in and out of MRI mode.  See the
   comment in do_scrub_chars.  */
static const char mri_pseudo[] = ".mri 0";

#if defined TC_ARM && defined OBJ_ELF
/* The pseudo-op for which we need to special-case `@' characters.
   See the comment in do_scrub_chars.  */
static const char   symver_pseudo[] = ".symver";
static const char * symver_state;
#endif

static char lex[256];
static const char symbol_chars[] =
"$._ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

#define LEX_IS_SYMBOL_COMPONENT		1
#define LEX_IS_WHITESPACE		2
#define LEX_IS_LINE_SEPARATOR		3
#define LEX_IS_COMMENT_START		4
#define LEX_IS_LINE_COMMENT_START	5
#define	LEX_IS_TWOCHAR_COMMENT_1ST	6
#define	LEX_IS_STRINGQUOTE		8
#define	LEX_IS_COLON			9
#define	LEX_IS_NEWLINE			10
#define	LEX_IS_ONECHAR_QUOTE		11
#ifdef TC_V850
#define LEX_IS_DOUBLEDASH_1ST		12
#endif
#ifdef TC_M32R
#define DOUBLEBAR_PARALLEL
#endif
#ifdef DOUBLEBAR_PARALLEL
#define LEX_IS_DOUBLEBAR_1ST		13
#endif
#define IS_SYMBOL_COMPONENT(c)		(lex[c] == LEX_IS_SYMBOL_COMPONENT)
#define IS_WHITESPACE(c)		(lex[c] == LEX_IS_WHITESPACE)
#define IS_LINE_SEPARATOR(c)		(lex[c] == LEX_IS_LINE_SEPARATOR)
#define IS_COMMENT(c)			(lex[c] == LEX_IS_COMMENT_START)
#define IS_LINE_COMMENT(c)		(lex[c] == LEX_IS_LINE_COMMENT_START)
#define	IS_NEWLINE(c)			(lex[c] == LEX_IS_NEWLINE)

static int process_escape PARAMS ((int));

/* FIXME-soon: The entire lexer/parser thingy should be
   built statically at compile time rather than dynamically
   each and every time the assembler is run.  xoxorich.  */

void
do_scrub_begin (m68k_mri)
     int m68k_mri ATTRIBUTE_UNUSED;
{
  const char *p;
  int c;

  lex[' '] = LEX_IS_WHITESPACE;
  lex['\t'] = LEX_IS_WHITESPACE;
  lex['\r'] = LEX_IS_WHITESPACE;
  lex['\n'] = LEX_IS_NEWLINE;
  lex[':'] = LEX_IS_COLON;

#ifdef TC_M68K
  scrub_m68k_mri = m68k_mri;

  if (! m68k_mri)
#endif
    {
      lex['"'] = LEX_IS_STRINGQUOTE;

#if ! defined (TC_HPPA) && ! defined (TC_I370)
      /* I370 uses single-quotes to delimit integer, float constants */
      lex['\''] = LEX_IS_ONECHAR_QUOTE;
#endif

#ifdef SINGLE_QUOTE_STRINGS
      lex['\''] = LEX_IS_STRINGQUOTE;
#endif
    }

  /* Note: if any other character can be LEX_IS_STRINGQUOTE, the loop
     in state 5 of do_scrub_chars must be changed.  */

  /* Note that these override the previous defaults, e.g. if ';' is a
     comment char, then it isn't a line separator.  */
  for (p = symbol_chars; *p; ++p)
    {
      lex[(unsigned char) *p] = LEX_IS_SYMBOL_COMPONENT;
    }				/* declare symbol characters */

  for (c = 128; c < 256; ++c)
    lex[c] = LEX_IS_SYMBOL_COMPONENT;

#ifdef tc_symbol_chars
  /* This macro permits the processor to specify all characters which
     may appears in an operand.  This will prevent the scrubber from
     discarding meaningful whitespace in certain cases.  The i386
     backend uses this to support prefixes, which can confuse the
     scrubber as to whether it is parsing operands or opcodes.  */
  for (p = tc_symbol_chars; *p; ++p)
    lex[(unsigned char) *p] = LEX_IS_SYMBOL_COMPONENT;
#endif

  /* The m68k backend wants to be able to change comment_chars.  */
#ifndef tc_comment_chars
#define tc_comment_chars comment_chars
#endif
  for (p = tc_comment_chars; *p; p++)
    {
      lex[(unsigned char) *p] = LEX_IS_COMMENT_START;
    }				/* declare comment chars */

  for (p = line_comment_chars; *p; p++)
    {
      lex[(unsigned char) *p] = LEX_IS_LINE_COMMENT_START;
    }				/* declare line comment chars */

  for (p = line_separator_chars; *p; p++)
    {
      lex[(unsigned char) *p] = LEX_IS_LINE_SEPARATOR;
    }				/* declare line separators */

  /* Only allow slash-star comments if slash is not in use.
     FIXME: This isn't right.  We should always permit them.  */
  if (lex['/'] == 0)
    {
      lex['/'] = LEX_IS_TWOCHAR_COMMENT_1ST;
    }

#ifdef TC_M68K
  if (m68k_mri)
    {
      lex['\''] = LEX_IS_STRINGQUOTE;
      lex[';'] = LEX_IS_COMMENT_START;
      lex['*'] = LEX_IS_LINE_COMMENT_START;
      /* The MRI documentation says '!' is LEX_IS_COMMENT_START, but
         then it can't be used in an expression.  */
      lex['!'] = LEX_IS_LINE_COMMENT_START;
    }
#endif

#ifdef TC_V850
  lex['-'] = LEX_IS_DOUBLEDASH_1ST;
#endif
#ifdef DOUBLEBAR_PARALLEL
  lex['|'] = LEX_IS_DOUBLEBAR_1ST;
#endif
#ifdef TC_D30V
  /* must do this is we want VLIW instruction with "->" or "<-" */
  lex['-'] = LEX_IS_SYMBOL_COMPONENT;
#endif
}				/* do_scrub_begin() */

/* Saved state of the scrubber */
static int state;
static int old_state;
static char *out_string;
static char out_buf[20];
static int add_newlines;
static char *saved_input;
static int saved_input_len;
static char input_buffer[32 * 1024];
static const char *mri_state;
static char mri_last_ch;

/* Data structure for saving the state of app across #include's.  Note that
   app is called asynchronously to the parsing of the .include's, so our
   state at the time .include is interpreted is completely unrelated.
   That's why we have to save it all.  */

struct app_save {
  int          state;
  int          old_state;
  char *       out_string;
  char         out_buf[sizeof (out_buf)];
  int          add_newlines;
  char *       saved_input;
  int          saved_input_len;
#ifdef TC_M68K
  int          scrub_m68k_mri;
#endif
  const char * mri_state;
  char         mri_last_ch;
#if defined TC_ARM && defined OBJ_ELF
  const char * symver_state;
#endif
};

char *
app_push ()
{
  register struct app_save *saved;

  saved = (struct app_save *) xmalloc (sizeof (*saved));
  saved->state = state;
  saved->old_state = old_state;
  saved->out_string = out_string;
  memcpy (saved->out_buf, out_buf, sizeof (out_buf));
  saved->add_newlines = add_newlines;
  if (saved_input == NULL)
    saved->saved_input = NULL;
  else
    {
      saved->saved_input = xmalloc (saved_input_len);
      memcpy (saved->saved_input, saved_input, saved_input_len);
      saved->saved_input_len = saved_input_len;
    }
#ifdef TC_M68K
  saved->scrub_m68k_mri = scrub_m68k_mri;
#endif
  saved->mri_state = mri_state;
  saved->mri_last_ch = mri_last_ch;
#if defined TC_ARM && defined OBJ_ELF
  saved->symver_state = symver_state;
#endif

  /* do_scrub_begin() is not useful, just wastes time.  */

  state = 0;
  saved_input = NULL;

  return (char *) saved;
}

void
app_pop (arg)
     char *arg;
{
  register struct app_save *saved = (struct app_save *) arg;

  /* There is no do_scrub_end ().  */
  state = saved->state;
  old_state = saved->old_state;
  out_string = saved->out_string;
  memcpy (out_buf, saved->out_buf, sizeof (out_buf));
  add_newlines = saved->add_newlines;
  if (saved->saved_input == NULL)
    saved_input = NULL;
  else
    {
      assert (saved->saved_input_len <= (int) (sizeof input_buffer));
      memcpy (input_buffer, saved->saved_input, saved->saved_input_len);
      saved_input = input_buffer;
      saved_input_len = saved->saved_input_len;
      free (saved->saved_input);
    }
#ifdef TC_M68K
  scrub_m68k_mri = saved->scrub_m68k_mri;
#endif
  mri_state = saved->mri_state;
  mri_last_ch = saved->mri_last_ch;
#if defined TC_ARM && defined OBJ_ELF
  symver_state = saved->symver_state;
#endif

  free (arg);
}				/* app_pop() */

/* @@ This assumes that \n &c are the same on host and target.  This is not
   necessarily true.  */
static int
process_escape (ch)
     int ch;
{
  switch (ch)
    {
    case 'b':
      return '\b';
    case 'f':
      return '\f';
    case 'n':
      return '\n';
    case 'r':
      return '\r';
    case 't':
      return '\t';
    case '\'':
      return '\'';
    case '"':
      return '\"';
    default:
      return ch;
    }
}

/* This function is called to process input characters.  The GET
   parameter is used to retrieve more input characters.  GET should
   set its parameter to point to a buffer, and return the length of
   the buffer; it should return 0 at end of file.  The scrubbed output
   characters are put into the buffer starting at TOSTART; the TOSTART
   buffer is TOLEN bytes in length.  The function returns the number
   of scrubbed characters put into TOSTART.  This will be TOLEN unless
   end of file was seen.  This function is arranged as a state
   machine, and saves its state so that it may return at any point.
   This is the way the old code used to work.  */

int
do_scrub_chars (get, tostart, tolen)
     int (*get) PARAMS ((char *, int));
     char *tostart;
     int tolen;
{
  char *to = tostart;
  char *toend = tostart + tolen;
  char *from;
  char *fromend;
  int fromlen;
  register int ch, ch2 = 0;

  /*State 0: beginning of normal line
	  1: After first whitespace on line (flush more white)
	  2: After first non-white (opcode) on line (keep 1white)
	  3: after second white on line (into operands) (flush white)
	  4: after putting out a .line, put out digits
	  5: parsing a string, then go to old-state
	  6: putting out \ escape in a "d string.
	  7: After putting out a .appfile, put out string.
	  8: After putting out a .appfile string, flush until newline.
	  9: After seeing symbol char in state 3 (keep 1white after symchar)
	 10: After seeing whitespace in state 9 (keep white before symchar)
	 11: After seeing a symbol character in state 0 (eg a label definition)
	 -1: output string in out_string and go to the state in old_state
	 -2: flush text until a '*' '/' is seen, then go to state old_state
#ifdef TC_V850
         12: After seeing a dash, looking for a second dash as a start of comment.
#endif
#ifdef DOUBLEBAR_PARALLEL
	 13: After seeing a vertical bar, looking for a second vertical bar as a parallel expression seperator.
#endif
	  */

  /* I added states 9 and 10 because the MIPS ECOFF assembler uses
     constructs like ``.loc 1 20''.  This was turning into ``.loc
     120''.  States 9 and 10 ensure that a space is never dropped in
     between characters which could appear in a identifier.  Ian
     Taylor, [e-mail].

     I added state 11 so that something like "Lfoo add %r25,%r26,%r27" works
     correctly on the PA (and any other target where colons are optional).
     Jeff Law, [e-mail].

     I added state 13 so that something like "cmp r1, r2 || trap #1" does not
     get squashed into "cmp r1,r2||trap#1", with the all important space
     between the 'trap' and the '#1' being eliminated.  [e-mail]  */

  /* This macro gets the next input character.  */

#define GET()							\
  (from < fromend						\
   ? * (unsigned char *) (from++)				\
   : (saved_input = NULL,					\
      fromlen = (*get) (input_buffer, sizeof input_buffer),	\
      from = input_buffer,					\
      fromend = from + fromlen,					\
      (fromlen == 0						\
       ? EOF							\
       : * (unsigned char *) (from++))))

  /* This macro pushes a character back on the input stream.  */

#define UNGET(uch) (*--from = (uch))

  /* This macro puts a character into the output buffer.  If this
     character fills the output buffer, this macro jumps to the label
     TOFULL.  We use this rather ugly approach because we need to
     handle two different termination conditions: EOF on the input
     stream, and a full output buffer.  It would be simpler if we
     always read in the entire input stream before processing it, but
     I don't want to make such a significant change to the assembler's
     memory usage.  */

#define PUT(pch)			\
  do					\
    {					\
      *to++ = (pch);			\
      if (to >= toend)			\
        goto tofull;			\
    }					\
  while (0)

  if (saved_input != NULL)
    {
      from = saved_input;
      fromend = from + saved_input_len;
    }
  else
    {
      fromlen = (*get) (input_buffer, sizeof input_buffer);
      if (fromlen == 0)
	return 0;
      from = input_buffer;
      fromend = from + fromlen;
    }

  while (1)
    {
      /* The cases in this switch end with continue, in order to
         branch back to the top of this while loop and generate the
         next output character in the appropriate state.  */