Re: [PATCH v2 1/3] softmmu: Do not use C99 // comments

[Markus Armbruster]

chaihaoyu <chaihaoyu1@huawei.com> writes:

> Hi, recently I found some code style problems while using checkpatch.pl 
> tool,please review.
>
> Date: Tue, 3 Nov 2020 11:01:40 +0800
> signed-off-by: Haoyu Chai<chaihaoyu1@huawei.com>
> ---
>  softmmu/memory.c         | 2 +-
>  softmmu/memory_mapping.c | 2 +-
>  softmmu/physmem.c        | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index 107ce0a4f8..5fb591b001 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -36,7 +36,7 @@
>  #include "hw/boards.h"
>  #include "migration/vmstate.h"
>
> -//#define DEBUG_UNASSIGNED
> +/* #define DEBUG_UNASSIGNED */
>
>  static unsigned memory_region_transaction_depth;
>  static bool memory_region_update_pending;
> diff --git a/softmmu/memory_mapping.c b/softmmu/memory_mapping.c
> index 18d0b8067c..f64053499e 100644
> --- a/softmmu/memory_mapping.c
> +++ b/softmmu/memory_mapping.c
> @@ -19,7 +19,7 @@
>  #include "exec/memory.h"
>  #include "exec/address-spaces.h"
>
> -//#define DEBUG_GUEST_PHYS_REGION_ADD
> +/* #define DEBUG_GUEST_PHYS_REGION_ADD */
>
>  static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
>                                                     MemoryMapping *mapping)
> diff --git a/softmmu/physmem.c b/softmmu/physmem.c
> index 44ffb60b5d..78c1b6580a 100644
> --- a/softmmu/physmem.c
> +++ b/softmmu/physmem.c
> @@ -75,7 +75,7 @@
>  #include <daxctl/libdaxctl.h>
>  #endif
>
> -//#define DEBUG_SUBPAGE
> +/* #define DEBUG_SUBPAGE */
>
>  /* ram_list is read under rcu_read_lock()/rcu_read_unlock().  Writes
>   * are protected by the ramlist lock.

I recommend to leave these alone.

CODING_STYLE.rst:

    Rationale: The // form is valid in C99, so this is purely a matter of
    consistency of style. The checkpatch script will warn you about this.

For "real" comments, we overwhelmingly use /* */, and avoiding // makes
sense.  Most exceptions are in code we copy from elsewhere, such as
disas/libvixl/.

For commenting out *code*, we use both forms.  Here are the counts for
commenting out macro definitions:

    $ git-grep '^/\* *# *define' | wc -l
    125
    $ git-grep '^// *# *define' | wc -l
    192