C - 找不到 memory 泄漏 (Valgrind)

Question

I'm new at covering memory leaks and I'm concerned about the problem of leaks. I'm using Valgrind.

I've solved most of it ye't I cant pinpoint where the last (14) leaks come from as I feel I'm freeing all allocated memory.

I've tried to go through all my mallocs/callocs without success. I've debugged for a while but no progress.

HEAP SUMMARY:
==9664==     in use at exit: 85 bytes in 14 blocks
==9664==   total heap usage: 105 allocs, 91 frees, 182,137 bytes allocated
==9664== 
==9664== 85 bytes in 14 blocks are definitely lost in loss record 1 of 1
==9664==    at 0x483877F: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)

void readline(FILE *file) {
   char line[120];
   while (fgets(ligne, 81, file)) {
      replace_words(line, words,  &i);
   }
}

Answer 1

Within the function placermots_tabs there is used the function strdup that dynamically allocates memory and returns a pointer to the allocated memory. And the allocated memory was not freed when the created character array by the function strdup was not required any more.

Here is the function

void placermots_tabs(char ligne[80], char **words, int *i) {
   char *word = strtok(ligne, " ,.-\n");
   while (word != NULL) {                  // strtok result controls the loop
      words[(*i)++] = strdup(word);
      word = strtok(NULL, " ,.-\n");
   }
}

Within the while loop there are dynamically allocated character arrays using the function strdup .

words[(*i)++] = strdup(word);

You need to track correctly the allocated memory: whether it was freed.

It seems the reason of the memory leak is the while loop within the function lire_lignes

void lire_lignes(FILE *file, char **words, int *nb_mots, struct Stats *stats) {
   int i = 0;
   char ligne[80];
   while (fgets(ligne, 81, file)) {
      placermots_tabs(ligne, words,  &i);
   }
   effacer_doublons(nb_mots, words);
   stats->mot_sans_doublons = *nb_mots;
   trouver_lettre_frequente((char const **) words, stats);
   fclose(file);
}

where the function placermots_tabs is called that overrides anew the array pointed to by the pointer words .