diff options
author | Gustavo A. R. Silva | 2020-02-24 10:43:46 -0600 |
---|---|---|
committer | David S. Miller | 2020-02-24 15:26:17 -0800 |
commit | cc5b48b567a2f668d6f301cb0dd08d65ff1f7fa2 (patch) | |
tree | cecd8606123980a383bf5dadf2a52eefc29e1ef5 /Documentation | |
parent | 040efdb14c39327da35d2fed902b31fcf4056188 (diff) |
freescale: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions