perf test: Check for linking problems in the python binding

It just will add the O= builddir to PYTHONPATH and try to 'use perf',
which will, in verbose mode show the python backtrace with the missing
symbols, such as in the problem fixed in the patch after this one:

  # perf test -v 15
  15: Try 'use perf' in python, checking link problems       :
  --- start ---
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
  ImportError: /home/acme/git/build/perf//python/perf.so: undefined symbol: test_attr__enabled
  ---- end ----
  Try 'use perf' in python, checking link problems: FAILED!
  #

Loooong overdue, done.

Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

4 files changed, 32 insertions, 0 deletions

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index c9f72b18e787..d0d79574403a 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -488,6 +488,7 @@ LIB_OBJS += $(OUTPUT)tests/evsel-roundtrip-name.o
 LIB_OBJS += $(OUTPUT)tests/evsel-tp-sched.o
 LIB_OBJS += $(OUTPUT)tests/pmu.o
 LIB_OBJS += $(OUTPUT)tests/hists_link.o
+LIB_OBJS += $(OUTPUT)tests/python-use.o
 
 BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
 BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
@@ -955,6 +956,9 @@ $(OUTPUT)tests/attr.o: tests/attr.c $(OUTPUT)PERF-CFLAGS
 		'-DBINDIR="$(bindir_SQ)"' \
 		$<
 
+$(OUTPUT)tests/python-use.o: tests/python-use.c $(OUTPUT)PERF-CFLAGS
+	$(QUIET_CC)$(CC) -o $@ -c $(ALL_CFLAGS) -DPYTHONPATH='"$(OUTPUT)/python"' $<
+
 $(OUTPUT)util/config.o: util/config.c $(OUTPUT)PERF-CFLAGS
 	$(QUIET_CC)$(CC) -o $@ -c $(ALL_CFLAGS) -DETC_PERFCONFIG='"$(ETC_PERFCONFIG_SQ)"' $<
 
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 479d10484a74..a164e4cd5f42 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -73,6 +73,10 @@ static struct test {
 		.func = test__hists_link,
 	},
 	{
+		.desc = "Try 'use perf' in python, checking link problems",
+		.func = test__python_use,
+	},
+	{
 		.func = NULL,
 	},
 };
diff --git a/tools/perf/tests/python-use.c b/tools/perf/tests/python-use.c
new file mode 100644
index 000000000000..15301f4ac3f1
--- /dev/null
+++ b/tools/perf/tests/python-use.c
@@ -0,0 +1,23 @@
+/*
+ * Just test if we can load the python binding.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "tests.h"
+
+extern int verbose;
+
+int test__python_use(void)
+{
+	char *cmd;
+	int ret;
+
+	if (asprintf(&cmd, "echo \"import sys ; sys.path.append('%s'); import perf\" | python %s",
+		     PYTHONPATH, verbose ? "" : "2> /dev/null") < 0)
+		return -1;
+
+	ret = system(cmd) ? -1 : 0;
+	free(cmd);
+	return ret;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 0bf106978094..0ded425b17d6 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -16,5 +16,6 @@ int test__attr(void);
 int test__dso_data(void);
 int test__parse_events(void);
 int test__hists_link(void);
+int test__python_use(void);
 
 #endif /* TESTS_H */