[tip:perf/core] tools lib subcmd: Respect WERROR=0 for build

[tip-bot for Chris Phlipot]

Commit-ID:  fd01d06ae33be63cff7d133e650cd1eb32f1d548
Gitweb:     http://git.kernel.org/tip/fd01d06ae33be63cff7d133e650cd1eb32f1d548
Author:     Chris Phlipot <cphlipot0@xxxxxxxxx>
AuthorDate: Thu, 30 Jun 2016 22:12:33 -0700
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 4 Jul 2016 20:27:26 -0300

tools lib subcmd: Respect WERROR=0 for build

this enables the workaround for compilers that generate warnings when
compiling libsubcmd.

Signed-off-by: Chris Phlipot <cphlipot0@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1467349955-1135-3-git-send-email-cphlipot0@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/lib/subcmd/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/lib/subcmd/Makefile b/tools/lib/subcmd/Makefile
index a810370..ce4b7e5 100644
--- a/tools/lib/subcmd/Makefile
+++ b/tools/lib/subcmd/Makefile
@@ -19,7 +19,13 @@ MAKEFLAGS += --no-print-directory
 LIBFILE = $(OUTPUT)libsubcmd.a
 
 CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
-CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fPIC
+CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -O6 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -fPIC
+
+# Treat warnings as errors unless directed not to
+ifneq ($(WERROR),0)
+  CFLAGS += -Werror
+endif
+
 CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
 
 CFLAGS += -I$(srctree)/tools/include/