Marc-André Lureau <marcandre.lur...@redhat.com> writes: > Accept 'if' key in top-level elements, accepted as string or list of > string type. The following patches will modify the test visitor to > check the value is correctly saved, and generate #if/#endif code (as a > single #if/endif line or a series for a list). > > Example of 'if' key: > { 'struct': 'TestIfStruct', 'data': { 'foo': 'int' }, > 'if': 'defined(TEST_IF_STRUCT)' } > > The generated code is for now *unconditional*. Later patches generate > the conditionals. > > A following patch for qapi-code-gen.txt will provide more complete > documentation for 'if' usage.
This paragraph looks obsolete now, because... > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com> > Reviewed-by: Markus Armbruster <arm...@redhat.com> > --- > scripts/qapi/common.py | 35 ++++++++++++++++++++---- > tests/test-qmp-cmds.c | 6 ++++ > docs/devel/qapi-code-gen.txt | 22 +++++++++++++++ ... you update documentation right in this patch (I like that). [...] > diff --git a/docs/devel/qapi-code-gen.txt b/docs/devel/qapi-code-gen.txt > index 88a70e4d45..7af60b48f3 100644 > --- a/docs/devel/qapi-code-gen.txt > +++ b/docs/devel/qapi-code-gen.txt > @@ -739,6 +739,28 @@ Example: Red Hat, Inc. controls redhat.com, and may > therefore add a > downstream command __com.redhat_drive-mirror. > > > +=== Configuring the schema === > + > +Top-level QAPI expressions. This sentence no verb :) I suspect an editing accident ate "can take an 'if' key". > The value must be a string or a list of > +string. s/string/strings/ > The corresponding generated code will then guard the inclusion > +of that member in the larger struct or function with #if IFCOND > +(or several #if lines for a list), where IFCOND is the value of the > +'if' key. "that member" makes little sense; top-level expressions aren't members. > + > +'struct', 'enum', 'union', 'alternate', 'command' and 'event' > +top-level QAPI expressions can take an 'if' keyword like: > + > +{ 'struct': 'IfStruct', 'data': { 'foo': 'int' }, > + 'if': 'defined(IFCOND)' } Repetitive. Moreover, I'd like to see the example spell out how conditions affect generated code. Here's my try: === Configuring the schema === The 'struct', 'enum', 'union', 'alternate', 'command' and 'event' top-level expressions can take an 'if' key. Its value must be a string or a list of strings. A string is shorthand for a list containing just that string. The code generated for the top-level expression will then be guarded by #if COND for each COND in the list. Example: a conditional struct { 'struct': 'IfStruct', 'data': { 'foo': 'int' }, 'if': ['defined(CONFIG_FOO)', 'defined(HAVE_BAR)'] } gets its generated code guarded like this: #if defined(CONFIG_FOO) #if defined(HAVE_BAR) ... generated code ... #endif /* defined(HAVE_BAR) */ #endif /* defined(CONFIG_FOO) */ > + > +Please note that you are responsible to ensure that the C code will > +compile with an arbitrary combination of conditions, since the > +generators are unable to check it at this point. > + > +The presence of 'if' keys in the schema is reflected through to the > +introspection output depending on the build configuration. > + > + > == Client JSON Protocol introspection == > > Clients of a Client JSON Protocol commonly need to figure out what [...] I'm happy to apply these proposals without a respin, if you like them.