qemu/tests/qapi-schema/reserved-member-q.json

# C member name collision
# We reject names like 'q-unix', because they can collide with the mangled
# name for 'unix' in generated C.
{ 'struct': 'Foo', 'data': { 'unix':'int', 'q-unix':'bool' } }
tests/qapi-schema: Test for reserved names, empty struct Add some testsuite coverage to ensure future patches are on the right track: Our current C representation of qapi arrays is done by appending 'List' to the element name; but we are not preventing the creation of an object type with the same name. Add reserved-type-list.json to test this. Then rename enum-union-clash.json to reserved-type-kind.json to cover the reservation that we DO detect, and shorten it to match the fact that the name is reserved even if there is no clash. We are failing to detect a collision between a dictionary member and the implicit 'has_*' flag for another optional member. The easiest fix would be for a future patch to reserve the entire "has[-_]" namespace for member names (the collision is also possible for branch names within flat unions, but only as long as branch names can collide with (non-variant) members; however, since future patches are about to remove that, it is not worth testing here). Add reserved-member-has.json to test this. A similar collision exists between a dictionary member where c_name() munges what might otherwise be a reserved name to start with 'q_', and another member explicitly starts with "q[-_]". Again, the easiest solution for a future patch will be reserving the entire namespace, but here for commands as well as members. Add reserved-member-q.json and reserved-command-q.json to test this; separate tests since arguably our munging of command 'unix' to 'qmp_q_unix()' could be done without a q_, which is different than the munging of a member 'unix' to 'foo.q_unix'. Finally, our testsuite does not have any compilation coverage of struct inheritance with empty qapi structs. Update qapi-schema-test.json to test this. Note that there is currently no technical reason to forbid type name patterns from member names, or member name patterns from types, since the two are not in the same namespace in C and won't collide; but it's not worth adding positive tests of these corner cases at this time, especially while there is other churn pending in patches that rearrange which collisions actually happen. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1445898903-12082-2-git-send-email-eblake@redhat.com> [Commit message tweaked slightly] Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-10-27 01:34:40 +03:00			`# C member name collision`
qapi: Reserve 'q_' and 'has_' member names c_name() produces names starting with 'q_' when protecting a dictionary member name that would fail to directly compile, but in doing so can cause clashes with any member name already beginning with 'q-' or 'q_'. Likewise, we create a C name 'has_' for any optional member that can clash with any member name beginning with 'has-' or 'has_'. Technically, rather than blindly reserving the namespace, we could try to complain about user names only when an actual collision occurs, or even teach c_name() how to munge names to avoid collisions. But it is not trivial, especially when collisions can occur across multiple types (such as via inheritance or flat unions). Besides, no existing .json files are trying to use these names. So it's easier to just outright forbid the potential for collision. We can always relax things in the future if a real need arises for QMP to express member names that have been forbidden here. 'has_' only has to be reserved for struct/union member names, while 'q_' is reserved everywhere (matching the fact that only members can be optional, while we use c_name() for munging both members and entities). Note that we could relax 'q_' restrictions on entities independently from member names; for example, c_name('qmp_' + 'unix') would result in a different function name than our current 'qmp_' + c_name('unix'). Update and add tests to cover the new error messages. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1445898903-12082-6-git-send-email-eblake@redhat.com> [Consistently pass protect=False to c_name(); commit message tweaked slightly] Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-10-27 01:34:44 +03:00			`# We reject names like 'q-unix', because they can collide with the mangled`
			`# name for 'unix' in generated C.`
tests/qapi-schema: Test for reserved names, empty struct Add some testsuite coverage to ensure future patches are on the right track: Our current C representation of qapi arrays is done by appending 'List' to the element name; but we are not preventing the creation of an object type with the same name. Add reserved-type-list.json to test this. Then rename enum-union-clash.json to reserved-type-kind.json to cover the reservation that we DO detect, and shorten it to match the fact that the name is reserved even if there is no clash. We are failing to detect a collision between a dictionary member and the implicit 'has_*' flag for another optional member. The easiest fix would be for a future patch to reserve the entire "has[-_]" namespace for member names (the collision is also possible for branch names within flat unions, but only as long as branch names can collide with (non-variant) members; however, since future patches are about to remove that, it is not worth testing here). Add reserved-member-has.json to test this. A similar collision exists between a dictionary member where c_name() munges what might otherwise be a reserved name to start with 'q_', and another member explicitly starts with "q[-_]". Again, the easiest solution for a future patch will be reserving the entire namespace, but here for commands as well as members. Add reserved-member-q.json and reserved-command-q.json to test this; separate tests since arguably our munging of command 'unix' to 'qmp_q_unix()' could be done without a q_, which is different than the munging of a member 'unix' to 'foo.q_unix'. Finally, our testsuite does not have any compilation coverage of struct inheritance with empty qapi structs. Update qapi-schema-test.json to test this. Note that there is currently no technical reason to forbid type name patterns from member names, or member name patterns from types, since the two are not in the same namespace in C and won't collide; but it's not worth adding positive tests of these corner cases at this time, especially while there is other churn pending in patches that rearrange which collisions actually happen. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1445898903-12082-2-git-send-email-eblake@redhat.com> [Commit message tweaked slightly] Signed-off-by: Markus Armbruster <armbru@redhat.com> 2015-10-27 01:34:40 +03:00			`{ 'struct': 'Foo', 'data': { 'unix':'int', 'q-unix':'bool' } }`