[OE-core] [PATCH 2/2] glibc: Disable Werror when building with debug options

[Andre McCurdy]

On Wed, Feb 27, 2019 at 12:51 PM Khem Raj <raj.khem at gmail.com> wrote:
>
> Since compiler does not optimize away a lot of stuff we end up with
> Werrors e.g.
>
> ./sysdeps/ieee754/flt-32/s_log1pf.c: In function '__log1pf':
> ../sysdeps/ieee754/flt-32/s_log1pf.c:114:22: error: 'c' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>   114 |        + (k * ln2_lo + c))) - f);
>       |          ~~~~~~~~~~~~^~~~
>
> which otherwise wont happen, so lets build with warnings-as-errors
> disabled in debug mode
>
> given we disable werror, now we don't have to restrict user to compile
> without -O0

Did you actually test with -O0? Even if it builds, there may be issues
at runtime:

  https://sourceware.org/glibc/wiki/FAQ#Why_do_I_get:.60.23error_.22glibc_cannot_be_compiled_without_optimization.22.27.2C_when_trying_to_compile_GNU_libc_with_GNU_CC.3F

> Signed-off-by: Khem Raj <raj.khem at gmail.com>
> ---
>  meta/recipes-core/glibc/glibc.inc     | 9 ---------
>  meta/recipes-core/glibc/glibc_2.29.bb | 1 +
>  2 files changed, 1 insertion(+), 9 deletions(-)
>
> diff --git a/meta/recipes-core/glibc/glibc.inc b/meta/recipes-core/glibc/glibc.inc
> index 67af396133..a382a22b73 100644
> --- a/meta/recipes-core/glibc/glibc.inc
> +++ b/meta/recipes-core/glibc/glibc.inc
> @@ -2,15 +2,6 @@ require glibc-common.inc
>  require glibc-ld.inc
>  require glibc-testing.inc
>
> -python () {
> -    opt_effective = "-O"
> -    for opt in d.getVar('SELECTED_OPTIMIZATION').split():
> -        if opt in ("-O0", "-O", "-O1", "-O2", "-O3", "-Os"):
> -            opt_effective = opt
> -    if opt_effective == "-O0":
> -        bb.fatal("%s can't be built with %s, try -O1 instead" % (d.getVar('PN'), opt_effective))
> -}
> -
>  DEPENDS = "virtual/${TARGET_PREFIX}gcc libgcc-initial linux-libc-headers"
>
>  PROVIDES = "virtual/libc"
> diff --git a/meta/recipes-core/glibc/glibc_2.29.bb b/meta/recipes-core/glibc/glibc_2.29.bb
> index bd8aa6d503..9b6fab066b 100644
> --- a/meta/recipes-core/glibc/glibc_2.29.bb
> +++ b/meta/recipes-core/glibc/glibc_2.29.bb
> @@ -90,6 +90,7 @@ EXTRA_OECONF = "--enable-kernel=${OLDEST_KERNEL} \
>                  --disable-crypt \
>                  --with-default-link \
>                  --enable-nscd \
> +                ${@bb.utils.contains_any('SELECTED_OPTIMIZATION', '-O0 -Og', '--disable-werror', '', d)} \
>                  ${GLIBCPIE} \
>                  ${GLIBC_EXTRA_OECONF}"
>
> --
> 2.21.0
>
> --
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