misc.c

C++版 词法分析、语法分析器

int is_hex_digit( ch )
int ch;

    {
    if ( isdigit( ch ) )
	return ( 1 );

    switch ( clower( ch ) )
	{
	case 'a':
	case 'b':
	case 'c':
	case 'd':
	case 'e':
	case 'f':
	    return ( 1 );

	default:
	    return ( 0 );
	}
    }


/* line_directive_out - spit out a "# line" statement */

void line_directive_out( output_file_name )
FILE *output_file_name;

    {
    if ( infilename && gen_line_dirs )
      {char *p;
        fprintf( output_file_name, "#line %d \"",linenum);
        for(p=infilename;*p;p++)
          if(*p=='"' || *p=='\\') fprintf(output_file_name,"\\%c",*p);
          else if(!isprint(*p)) fprintf(output_file_name,"\\%3.3o",*p);
          else fprintf(output_file_name,"%c",*p);
        fprintf( output_file_name,"\"\n");
      }
    }


/* mk2data - generate a data statement for a two-dimensional array
 *
 * synopsis
 *    int value;
 *    mk2data( value );
 *
 *  generates a data statement initializing the current 2-D array to "value"
 */
void mk2data( value )
int value;

    {
    if ( datapos >= NUMDATAITEMS )
	{
	putchar( ',' );
	dataflush();
	}

    if ( datapos == 0 )
	/* indent */
	fputs( "    ", stdout );

    else
	putchar( ',' );

    ++datapos;

    printf( "%5d", value );
    }


/* mkdata - generate a data statement
 *
 * synopsis
 *    int value;
 *    mkdata( value );
 *
 *  generates a data statement initializing the current array element to
 *  "value"
 */
void mkdata( value )
int value;

    {
    if ( datapos >= NUMDATAITEMS )
	{
	putchar( ',' );
	dataflush();
	}

    if ( datapos == 0 )
	/* indent */
	fputs( "    ", stdout );

    else
	putchar( ',' );

    ++datapos;

    printf( "%5d", value );
    }


/* myctoi - return the integer represented by a string of digits
 *
 * synopsis
 *    Char array[];
 *    int val, myctoi();
 *    val = myctoi( array );
 *
 */

int myctoi( array )
Char array[];

    {
    int val = 0;

    (void) sscanf( (char *) array, "%d", &val );

    return ( val );
    }


/* myesc - return character corresponding to escape sequence
 *
 * synopsis
 *    Char array[], c, myesc();
 *    c = myesc( array );
 *
 */

Char myesc( array )
Char array[];

    {
    Char c, esc_char;
    register int sptr;

    switch ( array[1] )
	{
#ifdef __STDC__
	case 'a': return ( '\a' );
#endif
	case 'b': return ( '\b' );
	case 'f': return ( '\f' );
	case 'n': return ( '\n' );
	case 'r': return ( '\r' );
	case 't': return ( '\t' );
	case 'v': return ( '\v' );

	case '0':
	case '1':
	case '2':
	case '3':
	case '4':
	case '5':
	case '6':
	case '7':
	case '8':
	case '9':
	    { /* \<octal> */
	    sptr = 1;

	    while ( isascii( array[sptr] ) && isdigit( array[sptr] ) )
		/* don't increment inside loop control because if
		 * isdigit() is a macro it might expand into multiple
		 * increments ...
		 */
		++sptr;

	    c = array[sptr];
	    array[sptr] = '\0';

	    esc_char = otoi( array + 1 );

	    array[sptr] = c;

	    return ( esc_char );
	    }

	case 'x':
	    { /* \x<hex> */
	    int sptr = 2;

	    while ( isascii( array[sptr] ) && is_hex_digit( array[sptr] ) )
		/* don't increment inside loop control because if
		 * isdigit() is a macro it might expand into multiple
		 * increments ...
		 */
		++sptr;

	    c = array[sptr];
	    array[sptr] = '\0';

	    esc_char = htoi( array + 2 );

	    array[sptr] = c;

	    return ( esc_char );
	    }

	default:
	    return ( array[1] );
	}
    }


/* otoi - convert an octal digit string to an integer value
 *
 * synopsis:
 *    int val, otoi();
 *    Char str[];
 *    val = otoi( str );
 */

int otoi( str )
Char str[];

    {
    int result;

    (void) sscanf( (char *) str, "%o", &result );

    return ( result );
    }


/* readable_form - return the the human-readable form of a character
 *
 * synopsis:
 *    int c;
 *    char *readable_form();
 *    <string> = readable_form( c );
 *
 * The returned string is in static storage.
 */

char *readable_form( c )
register int c;

    {
    static char rform[10];

    if ( (c >= 0 && c < 32) || c >= 127 )
	{
	switch ( c )
	    {
	    case '\n': return ( "\\n" );
	    case '\t': return ( "\\t" );
	    case '\f': return ( "\\f" );
	    case '\r': return ( "\\r" );
	    case '\b': return ( "\\b" );

	    default:
		(void) sprintf( rform, "\\%.3o", c );
		return ( rform );
	    }
	}

    else if ( c == ' ' )
	return ( "' '" );

    else
	{
	rform[0] = c;
	rform[1] = '\0';

	return ( rform );
	}
    }


/* reallocate_array - increase the size of a dynamic array */

void *reallocate_array( array, size, element_size )
void *array;
int size, element_size;

    {
    register void *new_array;

    /* same worry as in allocate_array(): */
    if ( size * element_size <= 0 )
        flexfatal( "attempt to increase array size by less than 1 byte" );

    new_array =
	(void *) realloc( (char *)array, (unsigned) (size * element_size ));

    if ( new_array == NULL )
	flexfatal( "attempt to increase array size failed" );

    return ( new_array );
    }

/* any_skelout - write out one section of any skeleton  file
 *
 * synopsis
 *    any_skelout(FILE *theskel,FILE *thefile,int *thecounter,char *thename,int use_name,int *back_lf);
 *
 * DESCRIPTION
 *    Copies from theskel to thefile until a line beginning with a single or more "%" or
 *    EOF is found.
 * convert @ to the value of lexer_name in name_defined!=0 and use_name!=0
 * generate comments and #line (#line only if thecounter!=NULL and  *back_lf!=1)
 * back_lf indicate that the last characters where backslash-newline
 * and it forbide #line because #line are not accepted in macro defs
 * do nothing if thefile==NULL
 */
void any_skelout(theskel,thefile,thecounter,thename,use_name,back_lf)
FILE *theskel,*thefile;
int *thecounter;
char *thename;
int use_name;
int *back_lf;
{int ch;
 int col=0;
 if(thefile==0 ) 
   return;
 if ( gen_line_dirs && thecounter!=(int *)0 && thename !=NULL && *back_lf!=1)
       {char *p;
        fprintf( thefile, "#line %d \"",*thecounter);
        for(p=thename;*p;p++)
          if(*p=='"' || *p=='\\') fprintf(thefile,"\\%c",*p);
          else if(!isprint(*p)) fprintf(thefile,"\\%3.3o",*p);
           else fprintf(thefile,"%c",*p);
        fprintf( thefile,"\"\n");
      }
 while((ch=getc(theskel))!=EOF)
  {col++;
   if(ch=='\\') *back_lf=-1;
   else if(ch=='\n' && *back_lf==-1) *back_lf=1;
   else if(ch=='%' && *back_lf==1) *back_lf=1;
   else *back_lf=0;
   if(ch=='@' && use_name) 
     {if(name_defined==0)
        { fprintf(thefile,"@Undefined_name@");
          if(thecounter!=(int *)0 && thename !=NULL)
            fprintf( stderr, "bad skeleton: %s, line %d\n", thename, *thecounter );
          flexfatal("@ found in skeleton before %%name \n");
        }
      else fprintf(thefile,"%s",lexer_name);
     }
   else if(ch=='\n')
     { putc(ch,thefile);
       col=0;
       if(thecounter!=(int *)0)
          (*thecounter)++;}
   else if(col==1 && ch=='%') 
     {fprintf(thefile,"/* ");
      while((ch=getc(theskel))!=EOF && ch!='\n') 
         putc(ch,thefile);
      fprintf(thefile," */ %s\n",(*back_lf==1)?"\\":"");  /* use \\\n to continue macros def */
      if(thecounter!=(int *)0)
          (*thecounter)++;
      return;
      }
   else putc(ch,thefile);
  };
}
/* action_out - write the actions from the temporary file to lex.yy.c
 *
 * synopsis
 *     action_out();
 *
 *     Copies the action file up to % (or end-of-file) to lex.yy.c
 */

void action_out()

{static int bklf=0;
 any_skelout(temp_action_file,stdout,(int *)0,(char *)0,0,&bklf);
}


/* skelout - write out one section of the skeleton file
 *
 * synopsis
 *    skelout();
 *
 * DESCRIPTION
 *    Copies from skelfile to stdout until a line beginning with "%" or
 *    EOF is found.... 
 */
void skelout()
{static int skel_line=1,bklf=0;
 any_skelout(skelfile,stdout,&skel_line,skelname,1,&bklf);
}
/* header_skeleton_out - write out one section of the skeleton header file
 *
 * synopsis
 *    header_skeleton_out();
 *
 * DESCRIPTION
 *    Copies from skelheaderfile to headerfile until a line beginning with a single or more "%" or
 *    EOF is found....
 * convert ...
 */

void header_skeleton_out()
{static int hskel_line=1,bklf=0;
     any_skelout(skelheaderfile,headerfile,&hskel_line,skelheaderfilename,1,&bklf);
    }

/* transition_struct_out - output a yy_trans_info structure
 *
 * synopsis
 *     int element_v, element_n;
 *     transition_struct_out( element_v, element_n );
 *
 * outputs the yy_trans_info structure with the two elements, element_v and
 * element_n.  Formats the output with spaces and carriage returns.
 */

void transition_struct_out( element_v, element_n )
int element_v, element_n;

    {
    printf( "%7d, %5d,", element_v, element_n );

    datapos += TRANS_STRUCT_PRINT_LENGTH;

    if ( datapos >= 75 )
	{
	putchar( '\n' );

	if ( ++dataline % 10 == 0 )
	    putchar( '\n' );

	datapos = 0;
	}
    }

/* set lexer name. check redefinition. */
/* if name==NULL and not yet defined use default value as if defined */
/* include section of sheader skeleton if definition made */
void set_lexer_name(name)
char *name;
{if(name==NULL)
   {
    if(name_defined==0)
     {name_defined++;
      fprintf( stderr,"No %%name given before line %d . Assuming %%name %s\n",
				 linenum, lexer_name );
     } else return;
    }
  else if(name_defined)
    {synerr( "Multiple %%name declaration" );return;}
  else 
   {strncpy(lexer_name,name,sizeof(lexer_name)-1);
    name_defined++;
   }
 fprintf(stdout,"#define YY_%s_FLEX_SCANNER\n",lexer_name);
 if ( ddebug )
   fprintf(headerfile, "#define YY_%s_FLEX_DEBUG\n",lexer_name );

 if ( csize == 256 )
   fprintf(headerfile, "#define YY_%s_CHAR unsigned char\n",lexer_name );
 else
   fprintf(headerfile, "#define YY_%s_CHAR char\n",lexer_name );
 header_skeleton_out();
}