linux-kernel - [PATCH 5/5] gcov: disable -Wmaybe-uninitialized warning

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Date:	Fri, 12 Feb 2016 17:06:22 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	Michal Marek <mmarek@...e.com>
Cc:	linux-arm-kernel@...ts.infradead.org,
	Peter Oberparleiter <oberpar@...ux.vnet.ibm.com>,
	linux-kbuild@...r.kernel.org, linux-kernel@...r.kernel.org,
	Arnd Bergmann <arnd@...db.de>
Subject: [PATCH 5/5] gcov: disable -Wmaybe-uninitialized warning

When gcov profiling is enabled, we see a lot of spurious warnings about
possibly uninitialized variables being used:

arch/arm/mm/dma-mapping.c: In function 'arm_coherent_iommu_map_page':
arch/arm/mm/dma-mapping.c:1085:16: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/clk/st/clk-flexgen.c: In function 'st_of_flexgen_setup':
drivers/clk/st/clk-flexgen.c:323:9: warning: 'num_parents' may be used uninitialized in this function [-Wmaybe-uninitialized]
kernel/cgroup.c: In function 'cgroup_mount':
kernel/cgroup.c:2119:11: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]

All of these are false positives, so it seems better to just disable
the warnings whenever GCOV is enabled. Most users don't enable GCOV,
and based on a prior patch, it is now also disabled for 'allmodconfig'
builds, so there should be no downsides of doing this.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 6bb89728a9d1..7b6900931a47 100644
--- a/Makefile
+++ b/Makefile
@@ -364,7 +364,7 @@ AFLAGS_MODULE   =
 LDFLAGS_MODULE  =
 CFLAGS_KERNEL	=
 AFLAGS_KERNEL	=
-CFLAGS_GCOV	= -fprofile-arcs -ftest-coverage -fno-tree-loop-im
+CFLAGS_GCOV	= -fprofile-arcs -ftest-coverage -fno-tree-loop-im -Wno-maybe-uninitialized
 CFLAGS_KCOV	= -fsanitize-coverage=trace-pc
 
 
-- 
2.7.0