[OE-core] [PATCH v3] gcc-sanitizers: fix -Werror=maybe-uninitialized issue

[Khem Raj]

On Mon, Apr 8, 2019 at 7:32 PM <mingli.yu at windriver.com> wrote:
>
> From: Mingli Yu <Mingli.Yu at windriver.com>
>
> When DEBUG_BUILD = "1" added in local.conf, there
> comes below build error when "bitbake gcc-sanitizers":
> | ./../../../../../../../../work-shared/gcc-8.3.0-r0/gcc-8.3.0/libsanitizer/libbacktrace/../../libbacktrace/elf.c: In function 'elf_is_symlink':
> | ../../../../../../../../../work-shared/gcc-8.3.0-r0/gcc-8.3.0/libsanitizer/libbacktrace/../../libbacktrace/elf.c:772:21: error: 'st.st_mode' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> |   return S_ISLNK (st.st_mode);
>
> Per https://gcc.gnu.org/ml/gcc-patches/2019-04/msg00315.html,
> the gcc upstream thinks the warning is a false
> positive and suggests to use -O2 rather than -Og
> or -O1 when compiling that file, so pass -Wno-error
> to compiler when -Og is used to silence the error.
>

Not particular to this change but in general if a package says that it
does not support -Og
then we are just going to get into more and more untested grounds
especially during runtime
so I wonder how useful it will be to use -Og for such packages or any
other non supported
combination for that matter.

> Signed-off-by: Mingli Yu <Mingli.Yu at windriver.com>
> ---
>  meta/recipes-devtools/gcc/gcc-sanitizers.inc | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/meta/recipes-devtools/gcc/gcc-sanitizers.inc b/meta/recipes-devtools/gcc/gcc-sanitizers.inc
> index e5e8452..8b1d1c9 100644
> --- a/meta/recipes-devtools/gcc/gcc-sanitizers.inc
> +++ b/meta/recipes-devtools/gcc/gcc-sanitizers.inc
> @@ -45,6 +45,9 @@ INHIBIT_DEFAULT_DEPS = "1"
>  ALLOW_EMPTY_${PN} = "1"
>  DEPENDS = "gcc-runtime virtual/${TARGET_PREFIX}gcc"
>
> +# used to fix ../../../../../../../../../work-shared/gcc-8.3.0-r0/gcc-8.3.0/libsanitizer/libbacktrace/../../libbacktrace/elf.c:772:21: error: 'st.st_mode' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> +DEBUG_OPTIMIZATION_append = " -Wno-error"
> +
>  BBCLASSEXTEND = "nativesdk"
>
>  PACKAGES = "${PN} ${PN}-dbg"
> --
> 2.7.4
>