[XEN PATCH 47/57] libs/stat: Fix and rework python-bindings build

[Anthony PERARD <anthony.perard@xxxxxxxxxx>]

Fix the dependency on the library, $(SHLIB) variable doesn't exist
anymore.

Rework dependency on the include file, we can let `swig` generate the
dependency for us with the use of "-M*" flags.

The xenstat.h file has moved so we need to fix the include location.

Rather than relaying on the VCS to create an empty directory for us,
we can create one before generating the *.c file for the bindings.

Make use of generic variable names to build a shared library from a
source file: CFLAGS, LDFLAGS, and LDLIBS.

Fix python's specific *flags by using python-config, and add them to
generic flags variables: CFLAGS, LDLIBS.

To build a shared library, we need to build the source file with
"-fPIC", which was drop by 6d0ec05390 (tools: split libxenstat into
new tools/libs/stat directory).

The source file generated by swig seems to be missing a prototype for
the "init" function, so we need "-Wno-missing-prototypes" in order to
build it.

Add some targets to .PHONY.

Signed-off-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---
 tools/libs/stat/Makefile                    | 27 +++++++++++++++------
 tools/libs/stat/bindings/swig/python/.empty |  1 -
 2 files changed, 19 insertions(+), 9 deletions(-)
 delete mode 100644 tools/libs/stat/bindings/swig/python/.empty

diff --git a/tools/libs/stat/Makefile b/tools/libs/stat/Makefile
index e39fe29bd1..d5d9cb3659 100644
--- a/tools/libs/stat/Makefile
+++ b/tools/libs/stat/Makefile
@@ -49,23 +49,34 @@ install-bindings: install-perl-bindings 
install-python-bindings
 .PHONY: uninstall-bindings
 uninstall-bindings: uninstall-perl-bindings uninstall-python-bindings
 
-$(BINDINGS): $(SHLIB) $(SHLIB_LINKS) include/xenstat.h
+$(BINDINGS): libxenstat.so
 
-SWIG_FLAGS=-module xenstat -Iinclude -I.
+SWIG_FLAGS = -module xenstat -I$(XEN_INCLUDE)
+SWIG_FLAGS += -MMD -MP -MF .$(if $(filter-out .,$(@D)),$(subst 
/,@,$(@D))@)$(@F).d
 
 # Python bindings
-PYTHON_VERSION=$(PYTHON:python%=%)
-PYTHON_FLAGS=-I/usr/include/python$(PYTHON_VERSION) -lpython$(PYTHON_VERSION)
 $(PYMOD): $(PYSRC)
 $(PYSRC): bindings/swig/xenstat.i
-       swig -python $(SWIG_FLAGS) -outdir $(@D) -o $(PYSRC) $<
-
+       mkdir -p $(@D)
+       swig -python $(SWIG_FLAGS) -outdir $(@D) -o $@ $<
+
+$(PYLIB): CFLAGS += $(shell $(PYTHON)-config --includes)
+$(PYLIB): CFLAGS += -fPIC
+$(PYLIB): CFLAGS += -Wno-missing-prototypes
+$(PYLIB): LDFLAGS += $(SHLIB_LDFLAGS)
+$(PYLIB): LDLIBS := $(shell $(PYTHON)-config --libs)
+$(PYLIB): LDLIBS += $(LDLIBS_libxenstat)
 $(PYLIB): $(PYSRC)
-       $(CC) $(CFLAGS) $(LDFLAGS) $(PYTHON_FLAGS) $(SHLIB_LDFLAGS) -lxenstat 
-o $@ $< $(APPEND_LDFLAGS)
+       $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $< $(LDLIBS) $(APPEND_LDFLAGS)
 
+.PHONY: python-bindings
 python-bindings: $(PYLIB) $(PYMOD)
 
-pythonlibdir=$(prefix)/lib/python$(PYTHON_VERSION)/site-packages
+pythonlibdir = $(shell $(PYTHON) -c \
+              'import distutils.sysconfig as cfg; \
+               print(cfg.get_python_lib(False, False, prefix="$(prefix)"))')
+
+.PHONY: install-python-bindings
 install-python-bindings: $(PYLIB) $(PYMOD)
        $(INSTALL_PROG) $(PYLIB) $(DESTDIR)$(pythonlibdir)/_xenstat.so
        $(INSTALL_PROG) $(PYMOD) $(DESTDIR)$(pythonlibdir)/xenstat.py
diff --git a/tools/libs/stat/bindings/swig/python/.empty 
b/tools/libs/stat/bindings/swig/python/.empty
deleted file mode 100644
index 2a8dd4274d..0000000000
--- a/tools/libs/stat/bindings/swig/python/.empty
+++ /dev/null
@@ -1 +0,0 @@
-This directory is empty; this file is included to prevent version control 
systems from removing the directory.
-- 
Anthony PERARD