c99 goto past initialization
Posted
by R Samuel Klatchko
on Stack Overflow
See other posts from Stack Overflow
or by R Samuel Klatchko
Published on 2010-05-12T18:27:42Z
Indexed on
2010/05/12
19:14 UTC
Read the original article
Hit count: 273
While debugging a crash, I came across this issue in some code:
int func()
{
char *p1 = malloc(...);
if (p1 == NULL)
goto err_exit;
char *p2 = malloc(...);
if (p2 == NULL)
goto err_exit;
...
err_exit:
free(p2);
free(p1);
return -1;
}
The problem occurs when the first malloc fails. Because we jump across the initialization of p2
, it contains random data and the call to free(p2)
can crash.
I would expect/hope that this would be treated the same way as in C++ where the compiler does not allow a goto to jump across an initialization.
My question: is jumping across an initialization allowed by the standard or is this a bug in gcc's implementation of c99?
© Stack Overflow or respective owner