fork(1) download 
  1. #include <stdio.h>
  2. #include <ctype.h>
  3. #include <stdlib.h>
  4. #include <string.h>
  5. #include <assert.h>
  6.  
  7.  
  8. const char *source = " \
  9. ABC equ 1h             \
  10. GHI equ 2h             \
  11. JKL equ 3h             \
  12. TUV equ 6h             \
  13. MNO equ 4h             \
  14. PQR equ 5h             \
  15.                        \
  16. cjne A,#ABC,def        \
  17.   mov GHI,#1h          \
  18.   mov JKL,MNO          \
  19. def:";
  20.  
  21. struct symbol_s {
  22.     char *name;
  23.     size_t count;
  24.  
  25.     struct symbol_s *next;
  26. };
  27.  
  28. void symbol_append_child(struct symbol_s *head, struct symbol_s *next)
  29. {
  30.     struct symbol_s *it;
  31.  
  32.     assert(head != NULL);
  33.     assert(next != NULL);
  34.  
  35.     it = head;
  36.  
  37.     while (it->next != NULL && (it = it->next)) { }
  38.  
  39.     it->next = next;
  40. }
  41.  
  42.  
  43. int main()
  44. {
  45.     int cursor = 0;
  46.     int c;
  47.     size_t source_length = strlen(source);
  48.  
  49.     struct symbol_s head = { 0 };
  50.  
  51.     while ((c = source[cursor]) != 0) {
  52.         if (isalpha(c)) {
  53.             int begin_cursor = cursor;
  54.  
  55.             while ((c = source[cursor++]) && isalnum(c)) {}
  56.  
  57.             if (isspace(c) && strncmp("equ", source + cursor, 3) == 0) {
  58.                 // If followed by "equ" it's a symbol declaration
  59.  
  60.                 struct symbol_s *symbol;
  61.  
  62.                 symbol = calloc(1, sizeof(*symbol));
  63.                 size_t len = cursor - begin_cursor - 1;
  64.  
  65.                 symbol->name = malloc(len);
  66.                 strncpy(symbol->name, source + begin_cursor, len);
  67.                 symbol->name[len] = 0;
  68.  
  69.                 symbol_append_child(&head, symbol);
  70.             } else {
  71.                 // treat alphanumeric string as a usage
  72.                 char buffer[512];
  73.                 size_t len = cursor - begin_cursor - 1;
  74.  
  75.                 strncpy(buffer, source + begin_cursor, len);
  76.                 buffer[len] = 0;
  77.  
  78.                 struct symbol_s *it;
  79.  
  80.                 for (it = &head; it != NULL; it = it->next) {
  81.                     if (it->name == NULL) {
  82.                         continue;
  83.                     }
  84.  
  85.                     if (strncmp(it->name, source + begin_cursor, len) == 0) {
  86.                         it->count += 1;
  87.                     }
  88.                 }
  89.                 continue;
  90.             }
  91.         }
  92.         cursor++;
  93.     }
  94.  
  95.     struct symbol_s *it;
  96.  
  97.     for (it = &head; it != NULL; it = it->next) {
  98.         if (it->name == NULL) {
  99.             continue;
  100.         }
  101.  
  102.         if (it->count == 0) {
  103.             printf("Unused symbol: %s\n", it->name, it->count);
  104.         }
  105.     }
  106.  
  107.     // clean up
  108.     struct symbol_s *prev;
  109.     for (prev = NULL, it = &head; it != NULL; prev = it, it = it->next) {
  110.         if (it->name == NULL) {
  111.             continue;
  112.         }
  113.  
  114.         if (prev != NULL && prev->name) {
  115.             free(prev->name);
  116.             free(prev);
  117.         }
  118.     }
  119.     free(prev->name);
  120.     free(prev);
  121.  
  122.     return 0;
  123. }
  124.  
Success #stdin #stdout 0s 4376KB
comments (?)
stdin 
Standard input is empty
stdout 
Unused symbol: TUV
Unused symbol: PQR
https://ideone.com/b3KggJ
language:
C (gcc 8.3)
created:
7 years ago
visibility:
public

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