qemu/tests/qapi-schema/union-int-branch.json

# we require union branches to be a struct
{ 'enum': 'TestEnum',
  'data': [ 'value1', 'value2' ] }
{ 'struct': 'Base',
  'data': { 'enum1': 'TestEnum' } }
{ 'struct': 'TestTypeB',
  'data': { 'integer': 'int' } }
{ 'union': 'TestUnion',
  'base': 'Base',
  'discriminator': 'enum1',
  'data': { 'value1': 'int',
            'value2': 'TestTypeB' } }
qapi: Drop simple unions Simple unions predate flat unions. Having both complicates the QAPI schema language and the QAPI generator. We haven't been using simple unions in new code for a long time, because they are less flexible and somewhat awkward on the wire. The previous commits eliminated simple union from the tree. Now drop them from the QAPI schema language entirely, and update mentions of "flat union" to just "union". Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20210917143134.412106-22-armbru@redhat.com> 2021-09-17 17:31:32 +03:00			`# we require union branches to be a struct`
qapi: Add some union tests Demonstrate that the qapi generator doesn't deal well with unions that aren't up to par. Later patches will update the expected reseults as the generator is made stricter. A few tests work as planned, but most show poor or missing error messages. Of particular note, qapi-code-gen.txt documents 'base' only for flat unions, but the tests here demonstrate that we currently allow a 'base' to a simple union, although it is exercised only in the testsuite. Later patches will remove this undocumented feature, to give us more flexibility in adding other future extensions to union types. For example, one possible extension is the idea of a type-safe simple enum, where added fields tie the discriminator to a user-defined enum type rather than creating an implicit enum from the names in 'data'. But adding such safety on top of a simple enum with a base type could look ambiguous with a flat enum; besides, the documentation also mentions how any simple union can be represented by an equivalent flat union. So it will be simpler to just outlaw support for something we aren't using. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-05-04 18:05:05 +03:00			`{ 'enum': 'TestEnum',`
			`'data': [ 'value1', 'value2' ] }`
qapi: Use 'struct' instead of 'type' in schema Referring to "type" as both a meta-type (built-in, enum, union, alternate, or struct) and a specific type (the name that the schema uses for declaring structs) is confusing. Do the bulk of the conversion to "struct" in qapi schema, with a fairly mechanical: for f in `find -name '*.json'; do sed -i "s/'type'/'struct'/"; done followed by manually filtering out the places where we have a 'type' embedded in 'data'. Then tweak a couple of tests whose output changes slightly due to longer lines. I also verified that the generated files for QMP and QGA (such as qmp-commands.h) are the same before and after, as assurance that I didn't leave in any accidental member name changes. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-05-04 18:05:27 +03:00			`{ 'struct': 'Base',`
qapi: Add some union tests Demonstrate that the qapi generator doesn't deal well with unions that aren't up to par. Later patches will update the expected reseults as the generator is made stricter. A few tests work as planned, but most show poor or missing error messages. Of particular note, qapi-code-gen.txt documents 'base' only for flat unions, but the tests here demonstrate that we currently allow a 'base' to a simple union, although it is exercised only in the testsuite. Later patches will remove this undocumented feature, to give us more flexibility in adding other future extensions to union types. For example, one possible extension is the idea of a type-safe simple enum, where added fields tie the discriminator to a user-defined enum type rather than creating an implicit enum from the names in 'data'. But adding such safety on top of a simple enum with a base type could look ambiguous with a flat enum; besides, the documentation also mentions how any simple union can be represented by an equivalent flat union. So it will be simpler to just outlaw support for something we aren't using. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-05-04 18:05:05 +03:00			`'data': { 'enum1': 'TestEnum' } }`
qapi: Use 'struct' instead of 'type' in schema Referring to "type" as both a meta-type (built-in, enum, union, alternate, or struct) and a specific type (the name that the schema uses for declaring structs) is confusing. Do the bulk of the conversion to "struct" in qapi schema, with a fairly mechanical: for f in `find -name '*.json'; do sed -i "s/'type'/'struct'/"; done followed by manually filtering out the places where we have a 'type' embedded in 'data'. Then tweak a couple of tests whose output changes slightly due to longer lines. I also verified that the generated files for QMP and QGA (such as qmp-commands.h) are the same before and after, as assurance that I didn't leave in any accidental member name changes. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-05-04 18:05:27 +03:00			`{ 'struct': 'TestTypeB',`
qapi: Add some union tests Demonstrate that the qapi generator doesn't deal well with unions that aren't up to par. Later patches will update the expected reseults as the generator is made stricter. A few tests work as planned, but most show poor or missing error messages. Of particular note, qapi-code-gen.txt documents 'base' only for flat unions, but the tests here demonstrate that we currently allow a 'base' to a simple union, although it is exercised only in the testsuite. Later patches will remove this undocumented feature, to give us more flexibility in adding other future extensions to union types. For example, one possible extension is the idea of a type-safe simple enum, where added fields tie the discriminator to a user-defined enum type rather than creating an implicit enum from the names in 'data'. But adding such safety on top of a simple enum with a base type could look ambiguous with a flat enum; besides, the documentation also mentions how any simple union can be represented by an equivalent flat union. So it will be simpler to just outlaw support for something we aren't using. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-05-04 18:05:05 +03:00			`'data': { 'integer': 'int' } }`
			`{ 'union': 'TestUnion',`
			`'base': 'Base',`
			`'discriminator': 'enum1',`
			`'data': { 'value1': 'int',`
			`'value2': 'TestTypeB' } }`