From 0a793ad34f137f146119ec4a4a90694ccab77ea3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 13 Apr 2016 17:35:00 +0100 Subject: [PATCH] drm/i915: Force clean compilation with -Werror Our driver compiles clean (nowadays thanks to 0day) but for me, at least, it would be beneficial if the compiler threw an error rather than a warning when it found a piece of suspect code. (I use this to compile-check patch series and want to break on the first compiler error in order to fix the patch.) v2: Kick off a new "Debugging" submenu for i915.ko At this point, we applied it to the kernel and promptly kicked it out again as it broke buildbots (due to a compiler warning on 32bits): commit 908d759b210effb33d927a8cb6603a16448474e4 Author: Daniel Vetter Date: Tue May 26 07:46:21 2015 +0200 Revert "drm/i915: Force clean compilation with -Werror" v3: Avoid enabling -Werror for allyesconfig/allmodconfig builds, using COMPILE_TEST as a suitable proxy suggested by Andrew Morton. (Damien) Only make the option available for EXPERT to reinforce that the option should not be casually enabled. Signed-off-by: Chris Wilson Cc: Jani Nikula Cc: Damien Lespiau Reviewed-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1460565315-7748-1-git-send-email-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/Kconfig.debug | 17 +++++++++++++++++ drivers/gpu/drm/i915/Makefile | 2 ++ 2 files changed, 19 insertions(+) diff --git a/drivers/gpu/drm/i915/Kconfig.debug b/drivers/gpu/drm/i915/Kconfig.debug index 649a562ddf17..61485c8ba3a8 100644 --- a/drivers/gpu/drm/i915/Kconfig.debug +++ b/drivers/gpu/drm/i915/Kconfig.debug @@ -1,3 +1,20 @@ +config DRM_I915_WERROR + bool "Force GCC to throw an error instead of a warning when compiling" + # As this may inadvertently break the build, only allow the user + # to shoot oneself in the foot iff they aim really hard + depends on EXPERT + # We use the dependency on !COMPILE_TEST to not be enabled in + # allmodconfig or allyesconfig configurations + depends on !COMPILE_TEST + default n + help + Add -Werror to the build flags for (and only for) i915.ko. + Do not enable this unless you are writing code for the i915.ko module. + + Recommended for driver developers only. + + If in doubt, say "N". + config DRM_I915_DEBUG bool "Enable additional driver debugging" depends on DRM_I915 diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 7ffb51b0cbc2..0b88ba0f3c1f 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -2,6 +2,8 @@ # Makefile for the drm device driver. This driver provides support for the # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher. +subdir-ccflags-$(CONFIG_DRM_I915_WERROR) := -Werror + # Please keep these build lists sorted! # core driver code -- 2.20.1