Add helpers to wrap generated code with #if/#endif lines.
A later patch wants to use QAPIGen for generating C snippets rather
than full C files with copyright headers etc. Splice in class
QAPIGenCCode between QAPIGen and QAPIGenC.
Add a 'with' statement context manager that will be used to wrap
generator visitor methods. The manager will check if code was
generated before adding #if/#endif lines on QAPIGenCSnippet
objects. Used in the following patches.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180703155648.11933-7-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
ded9fc28b5