bitbake: bitbake: BBHandler/ConfHandler: Improve multiline comment handling

Faced with an expression like:

 # Some comment \
 FOO = "bar"

what should bitbake do? Technically, the \ character means its multiline and
currently the code treats this as a continuation of the comment. This can
surprise some people and is not intuitive.

This patch makes bitbake simply error and asks the user to be clearer
about what they mean.

(Bitbake rev: 589d31ce41e019ee6a7cb6527d67bc76c0b6382a)

(Bitbake rev: 79c00fabe08b4c210a3bd81cfaffbc47ffdc2e2b)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/parse/parse_py/ConfHandler.py

@@ -98,15 +98,22 @@ def handle(fn, data, include):
     while True:
         lineno = lineno + 1
         s = f.readline()
-        if not s: break
+        if not s:
+            break
         w = s.strip()
-        if not w: continue          # skip empty lines
+        # skip empty lines
+        if not w:
+            continue
         s = s.rstrip()
-        if s[0] == '#': continue    # skip comments
         while s[-1] == '\\':
             s2 = f.readline().strip()
             lineno = lineno + 1
+            if s2 and s[0] == "#" and s2[0] != "#":
+                bb.fatal("There is a confusing multiline, partially commented expression on line %s of file %s (%s).\nPlease clarify whether this is all a comment or should be parsed." % (lineno, fn, s))
             s = s[:-1] + s2
+        # skip comments
+        if s[0] == '#':
+            continue
         feeder(lineno, s, fn, statements)
 
     # DONE WITH PARSING... time to evaluate