[PATCH 1/2] perf build: Add loading python binding check to python.so build

[Yang Jihong]

Add loading python binding check to python.so build so that problem can be
detected in advance in the build phase instead of being left to `perf test`
phase.

In normal scenarios, the original build is not affected:

  $ cd tools/perf
  $ rm -rf /tmp/perf; mkdir /tmp/perf; make O=/tmp/perf
  $ echo $?
  0
  $ cd /tmp/perf
  $ ./perf test python
   19: 'import perf' in python                    : Ok

Create an error scenario, for example, delete util/rlimit.c from
util/python-ext-sources:

  $ cd tools/perf
  $ sed -i 's@util/rlimit.c@#util/rlimit.c@g' util/python-ext-sources
  $ grep rlimit util/python-ext-sources
  #util/rlimit.c
  $ rm -rf /tmp/perf; mkdir /tmp/perf; make JOBS=1 O=/tmp/perf
  <SNIP>
    GEN     /tmp/perf/python/perf.cpython-310-x86_64-linux-gnu.so
  Error: Load python binding failed. See /tmp/perf/python_ext_build/lib//build.log for more details
  make[2]: *** [Makefile.perf:644: /tmp/perf/python/perf.cpython-310-x86_64-linux-gnu.so] Error 1
  make[1]: *** [Makefile.perf:242: sub-make] Error 2
  make: *** [Makefile:70: all] Error 2
  $ cat /tmp/perf/python_ext_build/lib//build.log
  Traceback (most recent call last):
    File "<string>", line 1, in <module>
  ImportError: /tmp/perf/python_ext_build/lib/perf.cpython-310-x86_64-linux-gnu.so: undefined symbol: rlimit__increase_nofile

Signed-off-by: Yang Jihong <yangjihong1@xxxxxxxxxx>
---
 tools/perf/Makefile.perf | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index d80dcaa5a1e3..a2449c4890ad 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -645,7 +645,13 @@ $(OUTPUT)python/perf$(PYTHON_EXTENSION_SUFFIX): $(PYTHON_EXT_SRCS) $(PYTHON_EXT_
         CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS)' \
 	  $(PYTHON_WORD) util/setup.py \
 	  --quiet build_ext; \
-	cp $(PYTHON_EXTBUILD_LIB)perf*.so $(OUTPUT)python/
+	$(PYTHON_WORD) -c 'import sys; sys.path.insert(0, "$(PYTHON_EXTBUILD_LIB)"); import perf' 2>$(PYTHON_EXTBUILD_LIB)/build.log; \
+	if [ $$? -ne 0 ]; then \
+		echo "Error: Load python binding failed. See $(PYTHON_EXTBUILD_LIB)/build.log for more details"; \
+		exit 1; \
+	else \
+		cp $(PYTHON_EXTBUILD_LIB)perf*.so $(OUTPUT)python/; \
+	fi
 
 python_perf_target:
 	@echo "Target is: $(OUTPUT)python/perf$(PYTHON_EXTENSION_SUFFIX)"
-- 
2.34.1