Subversion Repositories tms1000

/*
symtab.c: a simple binary tree symbol table
 
CASM is an assembler for the TMS1000 processor.
*/
 
#include <stdio.h>
#include <string.h>
#include "symtab.h"
 
typedef struct sym
{
  char *name;
  int value;
  int lineno;
  struct sym *left;
  struct sym *right;
} sym;
 
static char *newstr (char *orig)
{
  int len;
  char *r;
 
  len = strlen (orig);
  r = (char *) malloc (len + 10);
 
  if (! r)
    {
      fprintf (stderr, "memory allocation failed\n");
      exit (2);
    }
 
  memcpy (r, orig, len + 1);
  return (r);
}
 
t_symtab alloc_symbol_table (void)
{
  sym **table;
  table = (sym **) calloc (1, sizeof (sym *));
  return (table);
}
 
static void free_entry (sym *p)
{
  if (p->left)
    free_entry (p->left);
  if (p->right)
    free_entry (p->right);
  free (p);
}
 
void free_symbol_table (t_symtab t)
{
  sym **table = t;
  free_entry (*table);
  free (table);
}
 
static int insert_symbol (sym **p, sym *newsym)
{
  int i;
 
  if (! *p)
    {
      (*p) = newsym;
      return (1);
    }
 
  i = stricmp (newsym->name, (*p)->name);
 
  if (i == 0)
    return (0);
  else if (i < 0)
    return (insert_symbol (& ((*p)->left), newsym));
  else
    return (insert_symbol (& ((*p)->right), newsym));
}
 
 
/* returns 1 for success, 0 if duplicate name */
int create_symbol (t_symtab t, char *name, int value, int lineno)
{
  sym **table = t;
  sym *p = *table;
  sym *newsym;
 
  newsym = (sym *) calloc (1, sizeof (sym));
  if (! newsym)
    {
      fprintf (stderr, "memory allocation failure\n");
      exit (2);
    }
 
  newsym->name = newstr (name);
  newsym->value = value;
  newsym->lineno = lineno;
 
  return (insert_symbol (table, newsym));
}
 
/* returns 1 for success, 0 if not found */
int lookup_symbol (t_symtab t, char *name, int *value)
{
  sym **table = t;
  sym *p = *table;
  int i;
 
  while (p)
    {
      i = stricmp (name, p->name);
      if (i == 0)
	{
	  *value = p->value;
	  return (1);
	}
      if (i < 0)
	p = p->left;
      else
	p = p->right;
    }
  return (0);
}
 
static void print_symbols (FILE *f, sym *p)
{
  if (! p)
    return;
  print_symbols (f, p->left);
  fprintf (f, "%03x %s %d\n", p->value, p->name, p->lineno);
  print_symbols (f, p->right);
}
 
void print_symbol_table (t_symtab t, FILE *f)
{
  sym **table = t;
  print_symbols (f, *table);
}