aus_sammelwut/paulchen/ublu/ss08/abgabe/codea/.svn/text-base/symbol_table.c.svn-base

   1 #include <string.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include "symbol_table.h"
   5
   6 struct symbol_t *new_table(void) {
   7         return (struct symbol_t *)NULL;
   8 }
   9
  10 struct symbol_t *clone_table(struct symbol_t *table) {
  11         struct symbol_t *element;
  12         struct symbol_t *new_tablex;
  13
  14         element=table;
  15         new_tablex=new_table();
  16         while((struct symbol_t *)NULL!=element) {
  17                 /* check return value */
  18                 new_tablex=table_add_symbol(new_tablex,element->identifier,element->type,0,element->stack_offset);
  19                 element=element->next;
  20         }
  21
  22         return new_tablex;
  23 }
  24
  25 struct symbol_t *table_add_symbol(struct symbol_t *table, char *identifier, short type, short check, int stack_offset) {
  26         struct symbol_t *element;
  27         struct symbol_t *new_element;
  28
  29         if(table_lookup(table,identifier)!=(struct symbol_t *)NULL) {
  30                 if(check) {
  31                         fprintf(stderr,"Duplicate field %s.\n",identifier);
  32                         exit(3);
  33                 }
  34
  35                 table=table_remove_symbol(table,identifier);
  36         }
  37
  38         new_element=(struct symbol_t *)malloc(sizeof(struct symbol_t));
  39         new_element->next=(struct symbol_t *)NULL;
  40         new_element->identifier=strdup(identifier);
  41         new_element->type=type;
  42         new_element->stack_offset=stack_offset;
  43
  44         if((struct symbol_t *)NULL==table) {
  45                 return new_element;
  46         }
  47         element=table;
  48
  49         while((struct symbol_t *)NULL!=element->next) {
  50                 element=element->next;
  51         }
  52
  53         element->next=new_element;
  54
  55         return table;
  56 }
  57
  58 struct symbol_t *table_lookup(struct symbol_t *table, char *identifier) {
  59         struct symbol_t *element;
  60
  61         element=table;
  62
  63         if((struct symbol_t *)NULL==table) {
  64                 return (struct symbol_t *)NULL;
  65         }
  66
  67         if(strcmp(element->identifier,identifier)==0) {
  68                 return element;
  69         }
  70
  71         while((struct symbol_t *)NULL!=element->next) {
  72                 element=element->next;
  73                 if(strcmp(element->identifier,identifier)==0) {
  74                         return element;
  75                 }
  76         }
  77
  78         return (struct symbol_t *)NULL;
  79 }
  80
  81 struct symbol_t *table_merge(struct symbol_t *table, struct symbol_t *to_add, short check) {
  82         struct symbol_t *element;
  83         struct symbol_t *new_table=clone_table(table);
  84
  85         element=to_add;
  86         while(element!=(struct symbol_t *)NULL) {
  87                 printf("%s\n",element->identifier);
  88                 new_table=table_add_symbol(new_table,element->identifier,element->type,check,element->stack_offset);
  89                 element=element->next;
  90         }
  91
  92         return new_table;
  93 }
  94
  95 struct symbol_t *table_remove_symbol(struct symbol_t *table, char *identifier) {
  96         struct symbol_t *element;
  97         struct symbol_t *previous_element;
  98         struct symbol_t *new_element;
  99
 100         if((struct symbol_t *)NULL==table) {
 101                 return table;
 102         }
 103
 104         previous_element=(struct symbol_t *)NULL;
 105         element=table;
 106
 107         while((struct symbol_t *)NULL!=element) {
 108                 if(strcmp(element->identifier,identifier)==0) {
 109                         if((struct symbol_t *)NULL==previous_element) {
 110                                 new_element=element->next;
 111                         }
 112                         else {
 113                                 previous_element->next=element->next;
 114                                 new_element=table;
 115                         }
 116                         (void)free(element->identifier);
 117                         (void)free(element);
 118                         return new_element;
 119                 }
 120                 previous_element=element;
 121                 element=element->next;
 122         }
 123
 124         return table;
 125 }
 126
 127 void check_variable(struct symbol_t *table, char *identifier) {
 128         struct symbol_t *element=table_lookup(table,identifier);
 129         if(element!=(struct symbol_t *)NULL) {
 130                 if(element->type!=SYMBOL_TYPE_VAR && element->type!=SYMBOL_TYPE_PARAM) {
 131                         fprintf(stderr,"Identifier %s not a variable.\n",identifier);
 132                         exit(3);
 133                 }
 134         }
 135         else {
 136                 fprintf(stderr,"Unknown identifier %s.\n",identifier);
 137                 exit(3);
 138         }
 139 }
 140
 141 void check_field(struct symbol_t *table, char *identifier) {
 142         struct symbol_t *element=table_lookup(table,identifier);
 143         if(element!=(struct symbol_t *)NULL) {
 144                 if(element->type!=SYMBOL_TYPE_FIELD) {
 145                         fprintf(stderr,"Identifier %s not a variable.\n",identifier);
 146                         exit(3);
 147                 }
 148         }
 149         else {
 150                 fprintf(stderr,"Unknown identifier %s.\n",identifier);
 151                 exit(3);
 152         }
 153 }
 154