From: Nathan Chancellor Date: Mon, 6 Oct 2025 21:39:56 +0000 (-0700) Subject: scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for hostprogs X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7ded7d37e5f5b36b4acd74380156cf07b6640c5b;p=users%2Fhch%2Fmisc.git scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for hostprogs Commit 27758d8c2583 ("kbuild: enable -Werror for hostprogs") unconditionally enabled -Werror for the compiler, assembler, and linker when building the host programs, as the build footprint of the host programs is small (thus risk of build failures from warnings are low) and that stage of the build may not have Kconfig values (thus CONFIG_WERROR could not be used as a precondition). While turning warnings into errors unconditionally happens in a few places within the kernel, it can be disruptive to people who may be building with newer compilers, such as while doing a bisect. While it is possible to avoid this behavior by passing HOSTCFLAGS=-w or HOSTCFLAGS=-Wno-error, it may not be the most intuitive for regular users not intimately familiar with Kbuild. Avoid being disruptive to the entire build by depending on the explicit opt-in of CONFIG_WERROR or W=e to enable -Werror and the like while building the host programs. While this means there is a small portion of the build that does not have -Werror enabled (namely scripts/kconfig/* and scripts/basic/fixdep), it is better than not having it altogether. Fixes: 27758d8c2583 ("kbuild: enable -Werror for hostprogs") Acked-by: Miguel Ojeda Reported-by: Askar Safin Closes: https://lore.kernel.org/20251005011100.1035272-1-safinaskar@gmail.com/ Reviewed-by: Thomas Weißschuh Tested-by: Miguel Ojeda # Rust Link: https://patch.msgid.link/20251006-kbuild-hostprogs-werror-fix-v1-1-23cf1ffced5c@kernel.org Signed-off-by: Nathan Chancellor --- diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 1434cb6208cb..6af392f9cd02 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -223,9 +223,11 @@ KBUILD_USERCFLAGS += -Werror KBUILD_USERLDFLAGS += -Wl,--fatal-warnings KBUILD_RUSTFLAGS += -Dwarnings -endif - -# Hostprog flags are used during build bootstrapping and can not rely on CONFIG_ symbols. +# While hostprog flags are used during build bootstrapping (thus should not +# depend on CONFIG_ symbols), -Werror is disruptive and should be opted into. +# Only apply -Werror to hostprogs built after the initial Kconfig stage. KBUILD_HOSTCFLAGS += -Werror KBUILD_HOSTLDFLAGS += -Wl,--fatal-warnings KBUILD_HOSTRUSTFLAGS += -Dwarnings + +endif