[PATCH v2 18/18] perf clang: Define PERF_BUILTIN_CLANG for builtin clang compiling

[Wang Nan]

By this macro BPF script knows what compiler it is being built with.
Scripts prefer external clang can force fall back to it by:

 #ifdef PERF_BUILTIN_CLANG
 # error I prefer external clang compiler
 #endif

Signed-off-by: Wang Nan <wangn...@huawei.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: Alexei Starovoitov <a...@fb.com>
Cc: He Kuang <heku...@huawei.com>
Cc: Jiri Olsa <jo...@kernel.org>
---
 tools/perf/util/c++/clang.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
index a2de788..dd32f5d 100644
--- a/tools/perf/util/c++/clang.cpp
+++ b/tools/perf/util/c++/clang.cpp
@@ -62,6 +62,7 @@ createCompilerInvocation(llvm::opt::ArgStringList CFlags, 
StringRef& Path,
                "-vectorize-slp",
                "-Wno-unused-value",
                "-Wno-pointer-sign",
+               "-DPERF_BUILTIN_CLANG=1"
                "-x", "c"};
 
        CCArgs.append(CFlags.begin(), CFlags.end());
-- 
1.8.3.4