Re: [PATCH v3] qemu/atomic.h: rename atomic_ to qatomic_

[Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>]

On 9/23/20 12:56 PM, Stefan Hajnoczi wrote:
> clang's C11 atomic_fetch_*() functions only take a C11 atomic type
> pointer argument. QEMU uses direct types (int, etc) and this causes a
> compiler error when a QEMU code calls these functions in a source file
> that also included <stdatomic.h> via a system header file:
> 
>   $ CC=clang CXX=clang++ ./configure ... && make
>   ../util/async.c:79:17: error: address argument to atomic operation must be 
> a pointer to _Atomic type ('unsigned int *' invalid)
> 
> Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
> used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
> and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
> searched GitHub for existing "qatomic_" users but there seem to be none.
> 
> This patch was generated using:
> 
>   $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
>     sort -u >/tmp/changed_identifiers
>   $ for identifier in $(</tmp/changed_identifiers); do
>         sed -i "s%\<$identifier\>%q$identifier%g" \
>             $(git grep -I -l "\<$identifier\>")
>     done
> 
> I manually fixed line-wrap issues and misaligned rST tables.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>

Reviewed using 'git-diff --color-words'.

Reviewed-by: Philippe Mathieu-Daudé <philmd@xxxxxxxxxx>

> ---
> v3:
>  * Use qatomic_ instead of atomic_ [Paolo]
>  * The diff of my manual fixups is available here:
>    https://vmsplice.net/~stefan/atomic-namespace-pre-fixups-v3.diff
>    - Dropping #ifndef qatomic_fetch_add in atomic.h
>    - atomic_##X(haddr, val) glue macros not caught by grep
>    - Keep atomic_add-bench name
>    - C preprocessor backslash-newline ('\') column alignment
>    - Line wrapping
> v2:
>  * The diff of my manual fixups is available here:
>    https://vmsplice.net/~stefan/atomic-namespace-pre-fixups.diff
>    - Dropping #ifndef qemu_atomic_fetch_add in atomic.h
>    - atomic_##X(haddr, val) glue macros not caught by grep
>    - Keep atomic_add-bench name
>    - C preprocessor backslash-newline ('\') column alignment
>    - Line wrapping
>  * Use grep -I to avoid accidentally modifying binary files (RISC-V
>    OpenSBI ELFs) [Eric Blake]
>  * Tweak .gitorder to show atomic.h changes first [Eric Blake]
>  * Update grep commands in commit description so reviewers can reproduce
>    mechanical changes [Eric Blake]
> ---