relocatable.bbclass: Handle files which don't have read/write permissions

It's possible to have files in our sysroot which don't have the write (or in
some cases even the read) bit set. Test for these and if they are not set
temporarily set them so that we can chrpath the binaries.

Signed-off-by: Joshua Lock <josh@linux.intel.com>

meta/classes/relocatable.bbclass

@@ -5,12 +5,13 @@ PREPROCESS_RELOCATE_DIRS ?= ""
 
 def process_dir (directory, d):
     import subprocess as sub
+    import stat
 
     cmd = bb.data.expand('${CHRPATH_BIN}', d)
     tmpdir = bb.data.getVar('TMPDIR', d)
     basedir = bb.data.expand('${base_prefix}', d)
 
-    bb.debug("Checking %s for binaries to process" % directory)
+    #bb.debug("Checking %s for binaries to process" % directory)
     if not os.path.exists(directory):
         return
 
@@ -26,6 +27,17 @@ def process_dir (directory, d):
             process_dir(fpath, d)
         else:
             #bb.note("Testing %s for relocatability" % fpath)
+
+            # We need read and write permissions for chrpath, if we don't have
+            # them then set them temporarily. Take a copy of the files
+            # permissions so that we can restore them afterwards.
+            perms = os.stat(fpath)[stat.ST_MODE]
+            if os.access(fpath, os.W_OK|os.R_OK):
+                perms = None
+            else:
+                # Temporarily make the file writeable so we can chrpath it
+                os.chmod(fpath, perms|stat.S_IRWXU)
+
             p = sub.Popen([cmd, '-l', fpath],stdout=sub.PIPE,stderr=sub.PIPE)
             err, out = p.communicate()
             # If returned succesfully, process stderr for results
@@ -63,9 +75,12 @@ def process_dir (directory, d):
             # if we have modified some rpaths call chrpath to update the binary
             if len(new_rpaths):
                 args = ":".join(new_rpaths)
-                #bb.note("Setting rpath to " + args)
+                #bb.note("Setting rpath for %s to %s" %(fpath, args))
                 sub.call([cmd, '-r', args, fpath])
 
+            if perms:
+                os.chmod(fpath, perms)
+
 def rpath_replace (path, d):
     bindirs = bb.data.expand("${bindir} ${sbindir} ${base_sbindir} ${base_bindir} ${libdir} ${base_libdir} ${PREPROCESS_RELOCATE_DIRS}", d).split()