From f7795e4096d8bd1c767c5ddb450fa859ff20490e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Wed, 4 Mar 2020 16:38:15 +0100 Subject: misc: Replace zero-length arrays with flexible array member (automatic) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Description copied from Linux kernel commit from Gustavo A. R. Silva (see [3]): --v-- description start --v-- 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], 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 unadvertenly introduced [2] to the Linux codebase from now on. --^-- description end --^-- Do the similar housekeeping in the QEMU codebase (which uses C99 since commit 7be41675f7cb). All these instances of code were found with the help of the following Coccinelle script: @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; }; @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; } QEMU_PACKED; [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f [3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1 Inspired-by: Gustavo A. R. Silva Reviewed-by: David Hildenbrand Signed-off-by: Philippe Mathieu-Daudé Signed-off-by: Paolo Bonzini --- hw/nvram/eeprom93xx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'hw/nvram') diff --git a/hw/nvram/eeprom93xx.c b/hw/nvram/eeprom93xx.c index 07f0954..ca6f591 100644 --- a/hw/nvram/eeprom93xx.c +++ b/hw/nvram/eeprom93xx.c @@ -86,7 +86,7 @@ struct _eeprom_t { uint8_t addrbits; uint16_t size; uint16_t data; - uint16_t contents[0]; + uint16_t contents[]; }; /* Code for saving and restoring of EEPROM state. */ -- cgit v1.1