AST creation segfaults when input string input is larger than 9

Test Ouputs:

./parse -r
/[123456]/
Accepted!

./parse -r
/[1234567]/
zsh: segmentation fault (core dumped)  ./parse -r

This is my flex rule for the token. \[^?([^\\\]]|\\.)*\] {yylval.value = strdup(yytext); return TOKEN_RANGE; }

Which, gets passed to bison that passes it to add to the AST. range: TOKEN_RANGE {$$ = CreateAstLeaf(RANGE,$1);};

Below are the functions that create the AST.

ast_t *CreateAstNode(node_t type, ast_t *node_l, ast_t *node_r) {
  ast_t *new_node = malloc(sizeof(ast_t));
  if (!new_node) {
    perror("Out of space.");
    exit(1);
  }

  new_node->type = type;
  new_node->node_l = node_l;
  new_node->node_r = node_r;
  return new_node;
}

ast_t *CreateAstLeaf(node_t type, char *val) {
  ast_t *new_leaf = malloc(sizeof(ast_t));
  if (!new_leaf) {
    perror("Out of space.");
    exit(1);
  }

  if (val == NULL) {
    printf("No string recieved.\n");
    exit(1);
  }

  new_leaf->type = type;
  new_leaf->value = calloc(strlen(val) + 1, sizeof(char));
  strcpy(new_leaf->value, val);
  // printf("CREATNG:\tTYPE:%2d | VALUE: %5s\n", new_leaf->type,
  // new_leaf->value);

  return new_leaf;
}

I have already tested the tree creation and traversal and works correctly, but this only happened as I started creating the AST. As a string such as this /"this is a literal"/ got parsed correctly. I believe there is some confusion as to how yytext is used on my part.

Found the error, was treating all nodes the same even though the struct has an enum.

typedef struct ast {
  node_t type;
  union {
    struct {
      struct ast *node_l;
      struct ast *node_r;
    };
    char *value;
  };
} ast_t;

So,when the eval function reached a leaf node it was trying to access a string rather than a pointer to another node. Fix it by handling the eval function better.