Re: [PATCH 2/5] scripts/checkpatch.pl: Do not allow assert(0)

[Richard Henderson <richard.henderson@linaro.org>]

On 2/21/23 13:25, Philippe Mathieu-Daudé wrote:
> Since commit 262a69f428 ("osdep.h: Prohibit disabling assert()
> in supported builds") we can not build QEMU with NDEBUG (or
> G_DISABLE_ASSERT) defined, thus 'assert(0)' always aborts QEMU.
> 
> However some static analyzers / compilers doesn't notice NDEBUG
> can't be defined and emit warnings if code is used after an
> 'assert(0)' call. See for example commit c0a6665c3c ("target/i386:
> Remove compilation errors when -Werror=maybe-uninitialized").
> 
> Apparently such compiler isn't as clever with G_DISABLE_ASSERT,
> so we can silent these warnings by using g_assert_not_reached()
> which is easier to read anyway.
> 
> In order to avoid these annoying warnings, add a checkpatch rule
> to prohibit 'assert(0)'. Suggest using g_assert_not_reached()
> instead. For example when reverting the previous patch we get:
> 
>    ERROR: use g_assert_not_reached() instead of assert(0)
>    #21: FILE: target/ppc/dfp_helper.c:124:
>    +            assert(0); /* cannot get here */
> 
>    ERROR: use g_assert_not_reached() instead of assert(0)
>    #30: FILE: target/ppc/dfp_helper.c:141:
>    +            assert(0); /* cannot get here */
> 
>    total: 2 errors, 0 warnings, 16 lines checked
> 
> Signed-off-by: Philippe Mathieu-Daudé<philmd@linaro.org>
> ---
>   scripts/checkpatch.pl | 3 +++
>   1 file changed, 3 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~