HACKING: document preference for g_new instead of g_malloc

This patch documents the preference for g_new instead of g_malloc. The
reasons were adapted from commit b45c03f585.

Discussion in QEMU's mailing list:
  http://lists.nongnu.org/archive/html/qemu-devel/2018-05/msg03238.html

Cc: qemu-devel@nongnu.org
Cc: David Hildenbrand <david@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This commit is contained in:
Murilo Opsfelder Araujo 2018-05-15 10:49:50 -03:00 committed by Michael Tokarev
parent 0b816e986d
commit f7c922ed3d

View file

@ -118,6 +118,15 @@ Please note that g_malloc will exit on allocation failure, so there
is no need to test for failure (as you would have to with malloc).
Calling g_malloc with a zero size is valid and will return NULL.
Prefer g_new(T, n) instead of g_malloc(sizeof(T) * n) for the following
reasons:
a. It catches multiplication overflowing size_t;
b. It returns T * instead of void *, letting compiler catch more type
errors.
Declarations like T *v = g_malloc(sizeof(*v)) are acceptable, though.
Memory allocated by qemu_memalign or qemu_blockalign must be freed with
qemu_vfree, since breaking this will cause problems on Win32.