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author | Philippe Mathieu-Daudé <philmd@redhat.com> | 2020-03-04 16:38:15 +0100 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-16 22:07:42 +0100 |
commit | f7795e4096d8bd1c767c5ddb450fa859ff20490e (patch) | |
tree | c7767c88747e00be8118f81349bce043bc2f2959 /pc-bios | |
parent | 770275ed0c0ab05677472efcf184b1a02ab14d07 (diff) | |
download | qemu-f7795e4096d8bd1c767c5ddb450fa859ff20490e.zip qemu-f7795e4096d8bd1c767c5ddb450fa859ff20490e.tar.gz qemu-f7795e4096d8bd1c767c5ddb450fa859ff20490e.tar.bz2 |
misc: Replace zero-length arrays with flexible array member (automatic)
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 <gustavo@embeddedor.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'pc-bios')
-rw-r--r-- | pc-bios/s390-ccw/bootmap.h | 2 | ||||
-rw-r--r-- | pc-bios/s390-ccw/sclp.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/pc-bios/s390-ccw/bootmap.h b/pc-bios/s390-ccw/bootmap.h index 94f53a5..12a0166 100644 --- a/pc-bios/s390-ccw/bootmap.h +++ b/pc-bios/s390-ccw/bootmap.h @@ -136,7 +136,7 @@ typedef struct BootMapScriptHeader { typedef struct BootMapScript { BootMapScriptHeader header; - BootMapScriptEntry entry[0]; + BootMapScriptEntry entry[]; } __attribute__ ((packed)) BootMapScript; /* diff --git a/pc-bios/s390-ccw/sclp.h b/pc-bios/s390-ccw/sclp.h index 8450161..64b53ca 100644 --- a/pc-bios/s390-ccw/sclp.h +++ b/pc-bios/s390-ccw/sclp.h @@ -95,7 +95,7 @@ typedef struct EventBufferHeader { typedef struct WriteEventData { SCCBHeader h; EventBufferHeader ebh; - char data[0]; + char data[]; } __attribute__((packed)) WriteEventData; typedef struct ReadEventData { |