Re: [PATCH v3 5/5] configure: Add -Wno-psabi

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> On aarch64, gcc 9.3 is generating
>
> qemu/exec.c: In function ‘address_space_translate_iommu’:
> qemu/exec.c:431:28: note: parameter passing for argument of type \
>   ‘MemTxAttrs’ {aka ‘struct MemTxAttrs’} changed in GCC 9.1
>
> and many other reptitions.  This structure, and the functions
> amongst which it is passed, are not part of a QEMU public API.
> Therefore we do not care how the compiler passes the argument,
> so long as the compiler is self-consistent.
>
> The only portion of QEMU which does have a public api, and so
> must have a stable abi, is "qemu/plugin.h".  We test this by
> forcing -Wpsabi in tests/plugin/Makefile.
>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  configure             | 1 +
>  tests/plugin/Makefile | 2 +-
>  2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/configure b/configure
> index 5e27229f58..ba88fd1824 100755
> --- a/configure
> +++ b/configure
> @@ -2055,6 +2055,7 @@ add_to nowarn_flags -Wno-shift-negative-value
>  add_to nowarn_flags -Wno-string-plus-int
>  add_to nowarn_flags -Wno-typedef-redefinition
>  add_to nowarn_flags -Wno-tautological-type-limit-compare
> +add_to nowarn_flags -Wno-psabi
>  
>  gcc_flags="$warn_flags $nowarn_flags"
>  
> diff --git a/tests/plugin/Makefile b/tests/plugin/Makefile
> index b3250e2504..3a50451428 100644
> --- a/tests/plugin/Makefile
> +++ b/tests/plugin/Makefile
> @@ -17,7 +17,7 @@ NAMES += lockstep
>  
>  SONAMES := $(addsuffix .so,$(addprefix lib,$(NAMES)))
>  
> -QEMU_CFLAGS += -fPIC
> +QEMU_CFLAGS += -fPIC -Wpsabi
>  QEMU_CFLAGS += -I$(SRC_PATH)/include/qemu
>

It's a shame api.c includes enough headers to get tripped up but
hopefully this will catch enough of the breakage if/when it comes.

Anyway:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>


-- 
Alex Bennée