Christophe Lyon <christophe.l...@linaro.org> writes:
> When --enable-werror is enabled when running the top-level configure,
> it passes --enable-werror-always to subdirs. Some of them, like
> libgcc, ignore it.
>
> This patch adds support for it, enabled only for aarch64, to avoid
> breaking bootstrap for other targets.
>
> The patch also adds -Wno-prio-ctor-dtor to avoid a warning when compiling
> lse_init.c
>
> libgcc/
> * Makefile.in (WERROR): New.
> * config/aarch64/t-aarch64: Handle WERROR. Always use
> -Wno-prio-ctor-dtor.
> * configure.ac: Add support for --enable-werror-always.
> * configure: Regenerate.
> ---
> libgcc/Makefile.in | 1 +
> libgcc/config/aarch64/t-aarch64 | 1 +
> libgcc/configure | 31 +++++++++++++++++++++++++++++++
> libgcc/configure.ac | 5 +++++
> 4 files changed, 38 insertions(+)
>
> [...]
> diff --git a/libgcc/configure.ac b/libgcc/configure.ac
> index 4e8c036990f..6b3ea2aea5c 100644
> --- a/libgcc/configure.ac
> +++ b/libgcc/configure.ac
> @@ -13,6 +13,7 @@ sinclude(../config/unwind_ipinfo.m4)
> sinclude(../config/gthr.m4)
> sinclude(../config/sjlj.m4)
> sinclude(../config/cet.m4)
> +sinclude(../config/warnings.m4)
>
> AC_INIT([GNU C Runtime Library], 1.0,,[libgcc])
> AC_CONFIG_SRCDIR([static-object.mk])
> @@ -746,6 +747,10 @@ AC_SUBST(HAVE_STRUB_SUPPORT)
> # Determine what GCC version number to use in filesystem paths.
> GCC_BASE_VER
>
> +# Only enable with --enable-werror-always until existing warnings are
> +# corrected.
> +ACX_PROG_CC_WARNINGS_ARE_ERRORS([manual])
It looks like this is borrowed from libcpp and/or libdecnumber.
Those are a bit different from libgcc in that they're host libraries
that can be built with any supported compiler (including non-GCC ones).
In constrast, libgcc can only be built with the corresponding version
of GCC. The usual restrictions on -Werror -- only use it during stages
2 and 3, or if the user explicitly passes --enable-werror -- don't apply
in libgcc's case. We should always be building with the "right" version
of GCC (even for Canadian crosses) and so should always be able to use
-Werror.
So personally, I think we should just go with:
diff --git a/libgcc/config/aarch64/t-aarch64 b/libgcc/config/aarch64/t-aarch64
index b70e7b94edd..ae1588ce307 100644
--- a/libgcc/config/aarch64/t-aarch64
+++ b/libgcc/config/aarch64/t-aarch64
@@ -30,3 +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
...this, but with $(WERROR) replaced by -Werror.
At least, it would be a good way of finding out if there's a case
I've forgotten :)
Let's see what others think though.
Thanks,
Richard
