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lib/ts_fsm.c: 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
inadvertenly introduced[3] to the codebase from now on.

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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200211205813.GA25602@embeddedor
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alistair/sensors
Gustavo A. R. Silva 2020-04-06 20:10:03 -07:00 committed by Linus Torvalds
parent c6e2ac3b47
commit 842ae1f52b
1 changed files with 1 additions and 1 deletions

View File

@ -32,7 +32,7 @@
struct ts_fsm
{
unsigned int ntokens;
struct ts_fsm_token tokens[0];
struct ts_fsm_token tokens[];
};
/* other values derived from ctype.h */