writeobj.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 179 行

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
*    NON-INFRINGEMENT. Please see the License for the specific language
*    governing rights and limitations under the License.
*
*  ========================================================================
*
* Description:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
*               DESCRIBE IT HERE!
*
****************************************************************************/


#include <stdio.h>
#include <ctype.h>
#include "yacc.h"
#include "yaccins.h"
#include "alloc.h"

static FILE *tblout;

static char *opstr[] = {
  "_jl",        /* JLT */
  "_je",        /* JEQ */
  "_jg",        /* JGT */
  "_jle",       /* JLE */
  "_jne",       /* JNE */
  "_jge",       /* JGE */
  "ljmp",       /* JMP */
  "_lbl",       /* LBL */
  "_vcmp",      /* VCMP */
  "_tcmp",      /* TCMP */
  "_scan",      /* SCAN */
  "_call",      /* CALL */
  "_action",    /* ACTION */
  "_reduce"     /* REDUCE */
};

static unsigned opsize[] = {
  5,            /* JLT */
  5,            /* JEQ */
  5,            /* JGT */
  5,            /* JLE */
  5,            /* JNE */
  5,            /* JGE */
  3,            /* JMP */
  0,            /* LBL */
  3,            /* VCMP */
  2,            /* TCMP */
  3,            /* SCAN */
  3,            /* CALL */
  15,           /* ACTION */
  8             /* REDUCE */
};

typedef struct an_ins {
  char          opcode;
  short         offset;
} an_ins;

static an_ins *code;
static unsigned codeused, codeavail;

#define BLOCK   512

static int *lbladdr;

void writeobj( int maxlabel )
{
  tblout = fopen( "ytab.asm", "w" );
  if( tblout == NULL ) {
      msg( "cannot open 'ytab.asm'\n" );
  }
  fprintf( tblout, "INCLUDE ytabmac.inc\n" );
  fprintf( tblout, "_TEXT\tSEGMENT\n" );
  lbladdr = MALLOC( maxlabel, int );
  calcaddr();
  dumpcode();
  fprintf( tblout, "_TEXT\tENDS\n" );
  fprintf( tblout, "END\n" );
  fclose( tblout );
  free( code );
  free( lbladdr );
}


static calcaddr()
{
  an_ins *ins;
  unsigned j, insaddr;

  insaddr = 0;
  for( j = 0; j < codeused; ++j ){
      ins = &code[j];
      if( ins->opcode == LBL )
          lbladdr[ins->offset] = insaddr;
      insaddr += opsize[ins->opcode];
  }
}

static dumpcode()
{
  an_ins *ins;
  int offset;
  unsigned j;

  fprintf( tblout, "L:" );
  for( j = 0; j < codeused; ++j ){
      ins = &code[j];
      offset = ins->offset;
      fprintf( tblout, "\t%s", opstr[ins->opcode] );
      switch( ins->opcode ){
        case VCMP: case TCMP:
          if( isprint( offset ) && offset != '\'' && offset != '\\' )
              fprintf( tblout, "\t'%c'", offset );
          else
              fprintf( tblout, "\t%d", offset );
          break;
        case JLT: case JEQ: case JGT: case JLE: case JNE: case JGE: case JMP:
        case LBL: case CALL:
          if( offset > 0 )
              fprintf( tblout, "\tL+%d", lbladdr[offset] );
          else
              fprintf( tblout, "\tL%d", -offset );
          break;
        case ACTION:
          fprintf( tblout, "\t%d,%d", PROLEN(offset), PRONUM(offset) );
          break;
        case REDUCE:
          fprintf( tblout, "\t%d,%d", PROLEN(offset), PROLHS(offset) );
          break;
        default:
          ;
      }
      fprintf( tblout, "\n" );
  }
}

void emitins( unsigned opcode, unsigned offset )
{
  an_ins *ins;

  need( 1 );
  ins = &code[codeused++];
  ins->opcode = opcode;
  ins->offset = offset;
}

static need( n )
  unsigned n;
{
  if( codeused + n > codeavail ){
      codeavail += BLOCK;
      if( code )
          code = REALLOC( code, codeavail, an_ins );
      else
          code = MALLOC( codeavail, an_ins );
  }
}