Christophe Lyon <christophe.l...@linaro.org> writes:
> In commit r15-4417-g71c7b446b98aa5, I made -werror mandatory when
> building libgcc for aarch64.
>
> While it achieved its goal (make us fix problems unnoticed so far),
> there has a been a lot of debate because it couldn't be disabled
> easily.
As discussed off-list: you'd originally keyed that patch off
--enable-werror-always, in order to give an element of user control.
It was my fault that the -Werror ended up being unconditional.
AFAICT, using --enable-werror-always would have meant that only
bootstraps with the standard build config would get -Werror checking
by default. Cross builds wouldn't get it unless --enable-werror-always
was passed to top-level configure. Other bootstraps wouldn't get it
unless either --enable-werror or --enable-werror-always were passed
to top-level configure.
That would have created a new divergence between different build types.
But I went too far in saying that -Werror should be hard-coded, with no
way of disabling it at all.
> This patch adds support for --enable-werror/--disable-werror in
> libgcc, defaulting to --enable-werror for aarch4.
aarch64 :)
> Tested on non-bootstrap builds on aarch64-linux-gnu (with
> -Wno-prio-ctor-dtor removed in order to get an error).
>
> OK for trunk?
> And maybe backport to gcc-15 although gcc-15.2 was just released?
OK for trunk, and for GCC 15 after a grace period.
Thanks,
Richard
> libgcc/ChangeLog:
>
> PR libgcc/117600
> * Makefile.in (WERROR): New.
> * config/aarch64/t-aarch64: Handle WERROR.
> * configure: Regenerate.
> * configure.ac: Add support for --enable-werror.
> ---
> libgcc/Makefile.in | 1 +
> libgcc/config/aarch64/t-aarch64 | 2 +-
> libgcc/configure | 19 +++++++++++++++++++
> libgcc/configure.ac | 14 ++++++++++++++
> 4 files changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
> index f7b48dceb06..e258f943ddd 100644
> --- a/libgcc/Makefile.in
> +++ b/libgcc/Makefile.in
> @@ -87,6 +87,7 @@ CC = @CC@
> CFLAGS = @CFLAGS@
> RANLIB = @RANLIB@
> LN_S = @LN_S@
> +WERROR = @WERROR@
>
> PWD_COMMAND = $${PWDCMD-pwd}
>
> diff --git a/libgcc/config/aarch64/t-aarch64 b/libgcc/config/aarch64/t-aarch64
> index d4c59227386..c7d83c71843 100644
> --- a/libgcc/config/aarch64/t-aarch64
> +++ b/libgcc/config/aarch64/t-aarch64
> @@ -30,4 +30,4 @@ LIB2ADDEH += \
> $(srcdir)/config/aarch64/__arm_za_disable.S
>
> SHLIB_MAPFILES += $(srcdir)/config/aarch64/libgcc-sme.ver
> -LIBGCC2_CFLAGS += -Werror -Wno-prio-ctor-dtor
> +LIBGCC2_CFLAGS += $(WERROR) -Wno-prio-ctor-dtor
> diff --git a/libgcc/configure b/libgcc/configure
> index 18418336c9b..d5e80d227ff 100755
> --- a/libgcc/configure
> +++ b/libgcc/configure
> @@ -586,6 +586,7 @@ ac_unique_file="static-object.mk"
> ac_includes_default='/* none */'
> ac_subst_vars='LTLIBOBJS
> LIBOBJS
> +WERROR
> md_unwind_header
> md_unwind_def_header
> unwind_header
> @@ -720,6 +721,7 @@ enable_tm_clone_registry
> with_glibc_version
> enable_tls
> with_gcc_major_version_only
> +enable_werror
> '
> ac_precious_vars='build_alias
> host_alias
> @@ -1362,6 +1364,7 @@ Optional Features:
> installations without PT_GNU_EH_FRAME support
> --disable-tm-clone-registry disable TM clone registry
> --enable-tls Use thread-local storage [default=yes]
> + --enable-werror build with -Werror for selected targets
>
> Optional Packages:
> --with-PACKAGE[=ARG] use PACKAGE [ARG=yes]
> @@ -5789,6 +5792,22 @@ fi
>
>
>
> +# Check whether --enable-werror was given.
> +if test "${enable_werror+set}" = set; then :
> + enableval=$enable_werror;
> +case ${enable_werror} in
> + no) WERROR="" ;;
> + *) WERROR="-Werror" ;;
> +esac
> +
> +else
> +
> +WERROR="-Werror"
> +
> +fi
> +
> +
> +
> # We need multilib support.
> ac_config_files="$ac_config_files Makefile"
>
> diff --git a/libgcc/configure.ac b/libgcc/configure.ac
> index 85e4f1bc48b..65cd3c6aa1a 100644
> --- a/libgcc/configure.ac
> +++ b/libgcc/configure.ac
> @@ -733,6 +733,20 @@ AC_SUBST(md_unwind_header)
> AC_SUBST(sfp_machine_header)
> AC_SUBST(thread_header)
>
> +AC_ARG_ENABLE(werror,
> +[AS_HELP_STRING([--enable-werror],
> + [build with -Werror for selected targets])],
> +[
> +case ${enable_werror} in
> + no) WERROR="" ;;
> + *) WERROR="-Werror" ;;
> +esac
> +],
> +[
> +WERROR="-Werror"
> +])
> +AC_SUBST(WERROR)
> +
> # We need multilib support.
> AC_CONFIG_FILES([Makefile])
> AC_CONFIG_COMMANDS([default],
