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  1. #include <stdio.h>
  2.  
  3. void CauseUB(int a, int **b) {
  4.     *b = &a;
  5. }
  6. int main() {
  7.     int x = 5, *y = &x;
  8.     printf("This is OK: %d\n", *y);
  9.     CauseUB(x, &y); // Pointer to pointer
  10.     printf("Make sure stuff gets placed on the stack... %d\n", 2*x+13);
  11.     printf("This is UB: %d\n", *y);
  12.     return 0;
  13. }
  14.  
  15.  
Success #stdin #stdout 0s 2168KB
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stdin
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Standard input is empty
stdout
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This is OK: 5
Make sure stuff gets placed on the stack... 23
This is UB: 134514112
https://ideone.com/077Zmq
language:
C99 (gcc 8.3)
created:
8 years ago
visibility:
public

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