[Qemu-devel] [PATCH] HACKING: document preference for g_new instead of g_malloc

[Murilo Opsfelder Araujo]

This patch documents the preference for g_new instead of g_malloc. The
reasons were adapted from commit b45c03f585ea9bb1af76c73e82195418c294919d.

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

Cc: address@hidden
Cc: David Hildenbrand <address@hidden>
Cc: Eduardo Habkost <address@hidden>
Cc: Markus Armbruster <address@hidden>
Cc: Paolo Bonzini <address@hidden>
Signed-off-by: Murilo Opsfelder Araujo <address@hidden>
---
 HACKING | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/HACKING b/HACKING
index 4125c97d8d..0fc3e0fc04 100644
--- a/HACKING
+++ b/HACKING
@@ -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.
 
-- 
2.14.3