[PATCH v3 2/2] perf tools: Default to python version 2

[Thomas Ilsche <thomas.ilsche@tu-dresden.de>]

On 2014-08-02 15:20, Arnaldo Carvalho de Melo wrote:
> Maybe the way python was packaged on f14 is problematic, as you
> describe, but the fact is that python support is not working on that
> platform after this patch.
> 
> Could you please try to prepare a patch that does as you suggest so that
> I can try?

Please try the patch below.
I tested (compiles and perf script runs) with the combinations:

1) python  -> python2.x, python-config  -> python2.x-config
   python2 N/A,          python2-config N/A

2) python  -> python3.x, python-config  -> python3.x-config
   python2 -> python2.x, python2-config -> python2.x-config

3) python  -> python2.x, python-config  -> python2.x-config
   python2 -> python2.x, python2-config -> python2.x-config

4) python  -> python2.x, python-config  -> python2.x-config
   python2 -> python2.x, python2-config N/A

Based on / replaces the patch 2/2 by Namhyung Kim.

Signed-off-by: Thomas Ilsche <thomas.ilsche@tu-dresden.de>
---
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 9ee2008..0528cd37 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -104,10 +104,16 @@ ifdef PARSER_DEBUG
 endif
 
 ifndef NO_LIBPYTHON
-  override PYTHON := \
-    $(call get-executable-or-default,PYTHON,python)
+  # Try different combinations to accommodate systems that only have
+  # python[2][-config] in weird combinations but always preferring
+  # python2 and python2-config as per pep-0394. If we catch a
+  # python[-config] in version 3, the version check will kill it.
+  PYTHON2 := $(if $(call get-executable,python2),python2,python)
+  override PYTHON := $(call get-executable-or-default,PYTHON,$(PYTHON2))
+  PYTHON2_CONFIG := \
+    $(if $(call get-executable,$(PYTHON)-config),$(PYTHON)-config,python-config)
   override PYTHON_CONFIG := \
-    $(call get-executable-or-default,PYTHON_CONFIG,$(PYTHON)-config)
+    $(call get-executable-or-default,PYTHON_CONFIG,$(PYTHON2_CONFIG))
 
   PYTHON_CONFIG_SQ := $(call shell-sq,$(PYTHON_CONFIG))