[SECOND RESEND] [PATCH] tools/python: Pass linker to Python build process

[Elliott Mitchell <ehem+xen@xxxxxxx>]

Unexpectedly the environment variable which needs to be passed is
$LDSHARED and not $LD.  Otherwise Python may find the build `ld` instead
of the host `ld`.

Replace $(LDFLAGS) with $(SHLIB_LDFLAGS) as Python needs shared objects
it can load at runtime, not executables.

This uses $(CC) instead of $(LD) since Python distutils appends $CFLAGS
to $LDFLAGS which breaks many linkers.

Signed-off-by: Elliott Mitchell <ehem+xen@xxxxxxx>
---
This is now the *third* time this has been sent to the list.  Mark Pryor
has tested and confirms Python cross-building is working.  There is one
wart left which I'm unsure of the best approach for.

Having looked around a bit, I believe this is a Python 2/3 compatibility
issue.  "distutils" for Python 2 likely lacked a separate $LDSHARED or
$LD variable, whereas Python 3 does have this.  Alas this is pointless
due to the above (unless you can cause distutils.py to do the final link
step separately).
---
 tools/pygrub/Makefile | 9 +++++----
 tools/python/Makefile | 9 +++++----
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/tools/pygrub/Makefile b/tools/pygrub/Makefile
index 3063c4998f..37b2146214 100644
--- a/tools/pygrub/Makefile
+++ b/tools/pygrub/Makefile
@@ -3,20 +3,21 @@ XEN_ROOT = $(CURDIR)/../..
 include $(XEN_ROOT)/tools/Rules.mk
 
 PY_CFLAGS = $(CFLAGS) $(PY_NOOPT_CFLAGS)
-PY_LDFLAGS = $(LDFLAGS) $(APPEND_LDFLAGS)
+PY_LDFLAGS = $(SHLIB_LDFLAGS) $(APPEND_LDFLAGS)
 INSTALL_LOG = build/installed_files.txt
 
 .PHONY: all
 all: build
 .PHONY: build
 build:
-       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) 
setup.py build
+       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDSHARED="$(CC)" 
LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) setup.py build
 
 .PHONY: install
 install: all
        $(INSTALL_DIR) $(DESTDIR)/$(bindir)
-       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) \
-               setup.py install --record $(INSTALL_LOG) $(PYTHON_PREFIX_ARG) \
+       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDSHARED="$(CC)" \
+               LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) setup.py install \
+               --record $(INSTALL_LOG) $(PYTHON_PREFIX_ARG) \
                 --root="$(DESTDIR)" --install-scripts=$(LIBEXEC_BIN) --force
        set -e; if [ $(bindir) != $(LIBEXEC_BIN) -a \
                     "`readlink -f $(DESTDIR)/$(bindir)`" != \
diff --git a/tools/python/Makefile b/tools/python/Makefile
index 8d22c03676..b675f5b4de 100644
--- a/tools/python/Makefile
+++ b/tools/python/Makefile
@@ -5,19 +5,20 @@ include $(XEN_ROOT)/tools/Rules.mk
 all: build
 
 PY_CFLAGS = $(CFLAGS) $(PY_NOOPT_CFLAGS)
-PY_LDFLAGS = $(LDFLAGS) $(APPEND_LDFLAGS)
+PY_LDFLAGS = $(SHLIB_LDFLAGS) $(APPEND_LDFLAGS)
 INSTALL_LOG = build/installed_files.txt
 
 .PHONY: build
 build:
-       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" $(PYTHON) setup.py build
+       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDSHARED="$(CC)" 
LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) setup.py build
 
 .PHONY: install
 install:
        $(INSTALL_DIR) $(DESTDIR)$(LIBEXEC_BIN)
 
-       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) \
-               setup.py install --record $(INSTALL_LOG) $(PYTHON_PREFIX_ARG) \
+       CC="$(CC)" CFLAGS="$(PY_CFLAGS)" LDSHARED="$(CC)" \
+               LDFLAGS="$(PY_LDFLAGS)" $(PYTHON) setup.py install \
+               --record $(INSTALL_LOG) $(PYTHON_PREFIX_ARG) \
                --root="$(DESTDIR)" --force
 
        $(INSTALL_PYTHON_PROG) scripts/convert-legacy-stream 
$(DESTDIR)$(LIBEXEC_BIN)
-- 
2.20.1


-- 
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