[OE-core] [PATCH V2 2/2] populate_sdk_ext: consider custom configuration in local.conf

[Chen Qi]

Copy the contents of local.conf under TOPDIR into the final generated
local.conf. In this way, custom settings are also made into the final
local.conf like IMAGE_INSTALL, DISTRO_FEATURES, VIRTUAL-RUNTIME_xxx, etc.

Before this change, installing extensible SDK would usually report failure
when preparing the build system if the user has custom configuration for
DISTRO_FEATURES in local.conf. Also, items in IMAGE_INSTALL_append in local.conf
also don't get built correctly.

This patch solves the above problem.

A blacklist mechanism is also introduced so that we can blacklist variables that
should not be copied into the final local.conf file. Currently, the blacklist
contains 'TMPDIR', 'SSTATE_DIR', 'DL_DIR', 'STAMPS_DIR', 'BASE_WORKDIR' and
'DEPLOY_DIR'. What these variables have in common is that they are set in
bitbake.conf using '?=' or '??='.

This list of course doesn't cover every possible setting allowed in local.conf.
And it's possible that some setting in local.conf would still result in failure
when preparing build system at installation time of extensible SDK. The point
is that we want to make sure that reasonable settings like PACKAGECONFIG,
DISTRO_FEATURES, IMAGE_INSTALL, etc, don't result in failure which would
very much depress the users of extensible SDK.

[YOCTO #7616]

Signed-off-by: Chen Qi <Qi.Chen at windriver.com>
---
 meta/classes/populate_sdk_ext.bbclass | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/meta/classes/populate_sdk_ext.bbclass b/meta/classes/populate_sdk_ext.bbclass
index 2fc4c11..f08ba86 100644
--- a/meta/classes/populate_sdk_ext.bbclass
+++ b/meta/classes/populate_sdk_ext.bbclass
@@ -16,6 +16,7 @@ SDK_RDEPENDS_append_task-populate-sdk-ext = " ${SDK_TARGETS}"
 SDK_RELOCATE_AFTER_INSTALL_task-populate-sdk-ext = "0"
 
 SDK_META_CONF_WHITELIST ?= "MACHINE DISTRO PACKAGE_CLASSES"
+SDK_META_CONF_BLACKLIST ?= "TMPDIR DL_DIR SSTATE_DIR STAMPS_DIR BASE_WORKDIR DEPLOY_DIR"
 
 SDK_TARGETS ?= "${PN}"
 OE_INIT_ENV_SCRIPT ?= "oe-init-build-env"
@@ -114,6 +115,25 @@ python copy_buildsystem () {
         f.write('# this configuration provides, it is strongly suggested that you set\n')
         f.write('# up a proper instance of the full build system and use that instead.\n\n')
 
+        # Copy configurations from the current local.conf
+        builddir = d.getVar('TOPDIR', True)
+        with open(builddir + '/conf/local.conf', 'r') as lf:
+            varblacklist = d.getVar('SDK_META_CONF_BLACKLIST', True).split()
+            skip = False
+            for line in lf:
+                line = line.lstrip()
+                if line.startswith('#'):
+                    continue
+                for varname in varblacklist:
+                    if line.startswith(varname):
+                        skip = True
+                        break
+                if not skip:
+                    f.write(line)
+                skip = False
+        f.write('\n')
+
+        # Configurations in local.conf which are specific for extensible SDK
         f.write('INHERIT += "%s"\n\n' % 'uninative')
         f.write('CONF_VERSION = "%s"\n\n' % d.getVar('CONF_VERSION'))
 
-- 
1.9.1