[tip:perf/urgent] perf python: Make sure the python binding output directory is in place

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  f712a86c1406abf50b0dcff0500c723e2aca050a
Gitweb:     https://git.kernel.org/tip/f712a86c1406abf50b0dcff0500c723e2aca050a
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Thu, 3 Jan 2019 16:03:46 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 4 Jan 2019 12:55:24 -0300

perf python: Make sure the python binding output directory is in place

Instead of doing an unconditional mkdir, use a dummy Makefile variable
to check if the directory is there and if not, create it.

This is better than what we had and will help with other python bindings
that are in development, like one involved with python backtraces.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-iis6us2nocw3y4uuoon9osd7@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/Makefile.perf | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index ff29c3372ec3..2921f829a0f4 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -524,12 +524,14 @@ $(arch_errno_name_array): $(arch_errno_tbl)
 
 all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS)
 
+# Create python binding output directory if not already present
+_dummy := $(shell [ -d '$(OUTPUT)python' ] || mkdir -p '$(OUTPUT)python')
+
 $(OUTPUT)python/perf.so: $(PYTHON_EXT_SRCS) $(PYTHON_EXT_DEPS) $(LIBTRACEEVENT_DYNAMIC_LIST)
 	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared" \
         CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS) $(LIBTRACEEVENT_DYNAMIC_LIST_LDFLAGS)' \
 	  $(PYTHON_WORD) util/setup.py \
 	  --quiet build_ext; \
-	mkdir -p $(OUTPUT)python && \
 	cp $(PYTHON_EXTBUILD_LIB)perf*.so $(OUTPUT)python/
 
 please_set_SHELL_PATH_to_a_more_modern_shell: