ag/symtable.c

   1 #include <string.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include "symtable.h"
   5
   6 #define DD
   7
   8 static void check_gen(struct symbol *tab, char *ident, short type);
   9
  10 struct symbol *new_tab(void)
  11 {
  12         return SYMNULL;
  13 }
  14
  15 struct symbol *clone_tab(struct symbol *tab)
  16 {
  17         struct symbol *elm;
  18         struct symbol *new_tabx;
  19 #ifdef DD
  20         printf("clone_tab: tab(%08X)\n", tab);
  21 #endif
  22
  23         elm = tab;
  24         new_tabx = new_tab();
  25         while(elm != SYMNULL) {
  26                 new_tabx = tab_add_symbol(new_tabx, elm->ident, elm->type, 0);
  27                 elm = elm->next;
  28         }
  29
  30         return new_tabx;
  31 }
  32
  33 struct symbol *tab_add_symbol(struct symbol *tab, char *ident, short type, short check)
  34 {
  35         struct symbol *elm;
  36         struct symbol *new_elm;
  37 #ifdef DD
  38         printf("tab_add_symbol: tab(%08X), ident(%s), type(%i), check(%i)\n", tab, ident, type, check);
  39 #endif
  40
  41         if(tab_lookup(tab, ident, type) != SYMNULL) {
  42                 if(check) {
  43                         fprintf(stderr, "Identifier doppelt vorhanden: \"%s\"\n", ident);
  44                         exit(3);
  45                 } else {
  46                         tab = tab_remove_symbol(tab, ident, type);
  47                 }
  48         }
  49
  50         new_elm = (struct symbol *) malloc(sizeof(struct symbol));
  51         new_elm->next = SYMNULL;
  52         new_elm->ident = strdup(ident);
  53         new_elm->type = type;
  54
  55         if(tab == SYMNULL) {
  56                 return new_elm;
  57         }
  58
  59         elm = tab;
  60         while(elm->next != SYMNULL) {
  61                 elm = elm->next;
  62         }
  63         elm->next = new_elm;
  64
  65         return tab;
  66 }
  67
  68 struct symbol *tab_lookup(struct symbol *tab, char *ident, short type)
  69 {
  70         struct symbol *elm = tab;
  71
  72         if(tab == SYMNULL) {
  73                 return SYMNULL;
  74         }
  75
  76         do {
  77                 if((elm->type == type) && (strcmp(elm->ident, ident) == 0)) {
  78                         return elm;
  79                 }
  80                 elm = elm->next;
  81         } while(elm != SYMNULL);
  82
  83         return SYMNULL;
  84 }
  85
  86 struct symbol *tab_merge(struct symbol *tab, struct symbol *to_add, short check)
  87 {
  88         struct symbol *elm = to_add;
  89         struct symbol *new_tab = clone_tab(tab);
  90 #ifdef DD
  91         printf("tab_merge: tab(%08X), to_add(%08X), check(%i), new_tab(%08X)\n", tab, to_add, check, new_tab);
  92 #endif
  93
  94         while(elm != SYMNULL) {
  95                 new_tab = tab_add_symbol(new_tab, elm->ident, elm->type, check);
  96                 elm = elm->next;
  97         }
  98
  99         return new_tab;
 100 }
 101
 102 struct symbol *tab_remove_symbol(struct symbol *tab, char *ident, short type)
 103 {
 104         struct symbol *elm = tab;
 105         struct symbol *previous_elm = SYMNULL;
 106
 107         while(elm != SYMNULL) {
 108                 if((elm->type == type) && (strcmp(elm->ident, ident) == 0)) {
 109                         if(previous_elm == SYMNULL) {
 110                                 tab = elm->next;
 111                         } else {
 112                                 previous_elm->next = elm->next;
 113                         }
 114                         (void)free(elm->ident);
 115                         (void)free(elm);
 116                         break;
 117                 }
 118                 previous_elm = elm;
 119                 elm = elm->next;
 120         }
 121
 122         return tab;
 123 }
 124
 125 void check_variable(struct symbol *tab, char *ident)
 126 {
 127         check_gen(tab, ident, S_VAR);
 128 }
 129
 130 void check_field(struct symbol *tab, char *ident)
 131 {
 132         check_gen(tab, ident, S_FIELD);
 133 }
 134
 135 static void check_gen(struct symbol *tab, char *ident, short type)
 136 {
 137         struct symbol *elm = tab_lookup(tab, ident, type);
 138 #ifdef DD
 139         printf("check_variable: tab(%08X), ident(%s), type(%i), elm(%08X)\n", tab, ident, type, elm);
 140 #endif
 141         if(elm == SYMNULL) {
 142                 fprintf(stderr, "Unbekannter Identifier: \"%s\"\n", ident);
 143                 exit(3);
 144         }
 145 }
 146