sim/igen/table.h

/*  This file is part of the program psim.

    Copyright (C) 1994-1995, Andrew Cagney <cagney@highland.com.au>

    This program 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 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
    */


/* Read a table, line by line, from a file.

   A table line has several forms:

   Field line:

       <text> { ":" <text> }
       type == table_colon_entry

       Fields points to a NULL terminated list of pointers.

   Tab indented block:

     <tab> <text> <nl> { <tab> <text> <nl> }
     type == table_code_entry

     The leading tab at the start of each line is discarded.
     fields[i] is the i'th line with the <nl> discarded.
     

   Code block:

     "{" <ignore-text> <nl> { <text> <nl> } "}" <ignore-text> <nl>
     type == table_code_entry

     The leading/trailing {/} lines are discarded.
     Lines containing two leading spaces have those spaces striped.
     fields[i] is the i'th line with the <nl> discarded.

   In addition, the table parser reconises and handles internally the
   following (when not in a code block):

     "#" <line-nr> '"' <file> '"'

     As per CPP/CC, treat following lines as if they were taken from
     <file> starting at <line-nr>

   No support for CPP's "#if/#else/#endif" style conditions are
   planned. */

typedef struct _table table;

typedef enum {
  table_colon_entry,
  table_code_entry,
} table_entry_type;


typedef struct _table_entry table_entry;
struct _table_entry {
  table *file;
  line_ref *line;
  table_entry_type type;
  int nr_fields;
  char **field;
};

/* List of directories to search when opening a pushed file.  Current
   directory is always searched first */
typedef struct _table_include table_include;
struct _table_include {
  char *dir;
  table_include *next;
};


/* Open/read a table file.  Since the file is read once during open
   (and then closed immediatly) there is no close method. */

extern table *table_open
(const char *file_name);

extern table_entry *table_read
(table *file);


/* Push the the state of the current file and open FILE_NAME.  When
   the end of FILE_NAME is reached, return to the pushed file */

extern void table_push
(table *file,
 line_ref *line,
 table_include *search,
 const char *file_name);


/* Expand the specified field_nr using the internal expansion table.
   A field is only expanded when explicitly specified.  */

extern void table_expand_field
(table_entry *entry,
 int field_nr);


/* Given a code entry, write the code to FILE.  Since any
   leading/trailing braces were striped as part of the read, they are
   not written. */

extern void table_print_code
(lf *file,
 table_entry *entry);


/* Debugging */

extern void dump_line_ref
(lf *file,
 char *prefix,
 const line_ref *line,
 char *suffix);

extern void dump_table_entry
(lf *file,
 char *prefix,
 const table_entry *entry,
 char *suffix);



/* Utilities for skipping around text */

extern char *skip_digits
(char *chp);

extern char *skip_spaces
(char *chp);

extern char *skip_to_separator
(char *chp,
 char *separators);

extern char *back_spaces
(char *start,
 char *chp);