[PATCH v3] perf: perl: force to use stdbool.

[Wang Nan <wangnan0@huawei.com>]

When building perf for arm64 I hit a warning (and be treated as an
error) like below:

 aarch64-oe-linux-gcc -o .../scripts/perl/Perf-Trace-Util/Context.o -c -Wbad-function-cast \
	 ... scripts/perl/Perf-Trace-Util/Context.c

 In file included from .../usr/lib64/perl/5.14.3/CORE/perl.h:2464:0,
                  from Context.xs:23:
 /.../usr/lib64/perl/5.14.3/CORE/handy.h:108:0: error: "bool" redefined [-Werror]
  #  define bool char
  ^
 In file included from /.../usr/src/kernel/tools/include/linux/types.h:4:0,
                  from /.../usr/src/kernel/arch/arm64/include/uapi/asm/sigcontext.h:19,
		  from /.../usr/include/bits/sigcontext.h:27,
		  from /.../usr/include/signal.h:340,
		  from /.../usr/include/sys/param.h:28,
		  from /.../usr/lib64/perl/5.14.3/CORE/perl.h:678,
		  from Context.xs:23:
  /.../usr/lib/aarch64-oe-linux/gcc/aarch64-oe-linux/4.9.2/include/stdbool.h:33:0: note: this is the location of the previous definition
    #define bool _Bool

Looks like the failure is caused by arm64 uapi/asm/sigcontext.h, which
includes linux/types.h while other archs not.

Current perl consider this problem:

http://perl5.git.perl.org/perl.git/commit/bd31be4baa3ee68abdb92c0db3200efe0fad903b

So systems with perl later than v5.15.3 will be free of this bug.
However, old perl still exists in many main distributions.

This patch includes stdbool.h before Context.xs and define HAS_BOOL to
prevent perl'e headers define its own 'bool'. Code is learn from perl's
git tree.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/scripts/perl/Perf-Trace-Util/Context.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/scripts/perl/Perf-Trace-Util/Context.c b/tools/perf/scripts/perl/Perf-Trace-Util/Context.c
index 790ceba..28431d1 100644
--- a/tools/perf/scripts/perl/Perf-Trace-Util/Context.c
+++ b/tools/perf/scripts/perl/Perf-Trace-Util/Context.c
@@ -5,7 +5,10 @@
  *	ANY CHANGES MADE HERE WILL BE LOST! 
  *
  */
-
+#include <stdbool.h>
+#ifndef HAS_BOOL
+# define HAS_BOOL 1
+#endif
 #line 1 "Context.xs"
 /*
  * Context.xs.  XS interfaces for perf script.
-- 
1.8.4