base.bbclass: define PACKAGECONFIG_CONFARGS before only sometimes appending to it

* just to make sure it's expaned by bitbake before it gets
  executed in shell
* e.g. with cmake.bbclass and cmake recipe (any recipe without
  PACKAGECONFIG options have this issue) it looks like this:
  bitbake -e cmake | grep EXTRA_OECMAKE=
  EXTRA_OECMAKE="     -DCMAKE_DOC_DIR=share/doc/cmake-3.14
    -DCMAKE_USE_SYSTEM_LIBRARIES=1 -DCMAKE_USE_SYSTEM_LIBRARY_JSONCPP=0
    -DCMAKE_USE_SYSTEM_LIBRARY_LIBUV=0
    -DCMAKE_USE_SYSTEM_LIBRARY_LIBRHASH=0     -DKWSYS_CHAR_IS_SIGNED=1
    -DBUILD_CursesDialog=0     -DKWSYS_LFS_WORKS=1
    \${PACKAGECONFIG_CONFARGS}"

(From OE-Core rev: 745b63f4e11a6536cabd97013973562631a0e080)

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/meta/classes/base.bbclass b/meta/classes/base.bbclass
index 90af8ba72b..0c8a4b2862 100644
--- a/meta/classes/base.bbclass
+++ b/meta/classes/base.bbclass
@@ -15,6 +15,8 @@ OE_EXTRA_IMPORTS ?= ""
 OE_IMPORTS += "os sys time oe.path oe.utils oe.types oe.package oe.packagegroup oe.sstatesig oe.lsb oe.cachedpath oe.license ${OE_EXTRA_IMPORTS}"
 OE_IMPORTS[type] = "list"
 
+PACKAGECONFIG_CONFARGS ??= ""
+
 def oe_import(d):
     import sys