[PATCH RFC 06/10] python3: support profile optimized build

[Markus Lehtonen <markus.lehtonen@linux.intel.com>]

Make it possible to do profile-optimized build. The implementation is
virtually identical to how we do it in Python 2.7. Basically, you need
to define PYTHON3_PROFILE_OPT = "1" in your local.conf and have profile
data available in the location pointed to by PYTHON3_PROFILE_DIR.
Profile data can be obtainen e.g. by running bitbake python-pgo-image -c
profile3.

[YOCTO #9338]

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
---
 meta/recipes-devtools/python/python3_3.5.2.bb | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/meta/recipes-devtools/python/python3_3.5.2.bb b/meta/recipes-devtools/python/python3_3.5.2.bb
index ead8a0d..7e629b8 100644
--- a/meta/recipes-devtools/python/python3_3.5.2.bb
+++ b/meta/recipes-devtools/python/python3_3.5.2.bb
@@ -77,6 +77,17 @@ export CROSSPYTHONPATH = "${STAGING_LIBDIR_NATIVE}/python${PYTHON_MAJMIN}/lib-dy
 # No ctypes option for python 3
 PYTHONLSBOPTS = ""
 
+# Automatic profile guided optimization
+PYTHON3_MAKE_TARGET ?= "${@'build_all_use_profile' if d.getVar('PYTHON3_PROFILE_OPT', True) == '1' else ''}"
+PYTHON3_PROFILE_DIR ?= "${@'${TMPDIR}/work-shared/${MACHINE}/python3/pgo-data' if d.getVar('PYTHON3_PROFILE_OPT', True) == '1' else ''}"
+python () {
+    if (d.getVar('PYTHON3_PROFILE_OPT', True) == '1' and
+            d.getVar('PYTHON3_MAKE_TARGET', True) == 'build_all_use_profile'):
+        profile_dir = d.getVar('PYTHON3_PROFILE_DIR', True)
+        bb.utils.mkdirhier(profile_dir)
+        d.setVarFlag('do_compile', 'file-checksums', '%s:True' % profile_dir)
+}
+
 do_configure_append() {
 	rm -f ${S}/Makefile.orig
 	autoreconf -Wcross --verbose --install --force --exclude=autopoint ../Python-${PV}/Modules/_ctypes/libffi
@@ -116,6 +127,10 @@ do_compile() {
     if [ "${PYTHON3_MAKE_TARGET}" = "build_all_generate_profile" ]; then
         # This is only used in PGO profiling by python-profile-opt package
         export EXTRA_CFLAGS="-fprofile-dir=./python3-pgo-profiles/"
+    elif [ -n "${PYTHON3_PROFILE_DIR}" ]; then
+            export EXTRA_CFLAGS="-fprofile-dir=${PYTHON3_PROFILE_DIR}"
+            # Remove non-optimized build artefacts
+            oe_runmake clean
     fi
 
 	oe_runmake HOSTPGEN=${STAGING_BINDIR_NATIVE}/python3-native/pgen \
@@ -136,6 +151,11 @@ do_install() {
 	install -d ${D}${libdir}/pkgconfig
 	install -d ${D}${libdir}/python${PYTHON_MAJMIN}/config
 
+    # This only has effect if we build with -fprofile-use, e.g. when make
+    # target is build_all_use_profile
+    if [ -n "${PYTHON3_PROFILE_DIR}" ]; then
+        export EXTRA_CFLAGS="-fprofile-dir=${PYTHON3_PROFILE_DIR}"
+    fi
 	# rerun the build once again with original makefile this time
 	# run install in a separate step to avoid compile/install race
 	oe_runmake HOSTPGEN=${STAGING_BINDIR_NATIVE}/python3-native/pgen \
-- 
2.10.2