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author | Eric Blake <eblake@redhat.com> | 2016-02-17 23:48:24 -0700 |
---|---|---|
committer | Markus Armbruster <armbru@redhat.com> | 2016-02-19 11:08:57 +0100 |
commit | 1de5d4ca0752138034305f3d4e8fe17ef6503569 (patch) | |
tree | c914df4f8dd7a66c0b00f040812da69f477b1488 /scripts | |
parent | e65d89bf1a4484e0db0f3dc820a8b209f2fb1e8b (diff) | |
download | qemu-1de5d4ca0752138034305f3d4e8fe17ef6503569.zip qemu-1de5d4ca0752138034305f3d4e8fe17ef6503569.tar.gz qemu-1de5d4ca0752138034305f3d4e8fe17ef6503569.tar.bz2 |
qapi: Emit structs used as variants in topological order
Right now, we emit the branches of union types as a boxed pointer,
and it suffices to have a forward declaration of the type. However,
a future patch will swap things to directly use the branch type,
instead of hiding it behind a pointer. For this to work, the
compiler needs the full definition of the type, not just a forward
declaration, prior to the union that is including the branch type.
This patch just adds topological sorting to hoist all types
mentioned in a branch of a union to be fully declared before the
union itself. The sort is always possible, because we do not
allow circular union types that include themselves as a direct
branch (it is, however, still possible to include a branch type
that itself has a pointer to the union, for a type that can
indirectly recursively nest itself - that remains safe, because
that the member of the branch type will remain a pointer, and the
QMP representation of such a type adds another {} for each recurring
layer of the union type).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1455778109-6278-11-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Diffstat (limited to 'scripts')
-rw-r--r-- | scripts/qapi-types.py | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py index 83f230a..6ea0ae6 100644 --- a/scripts/qapi-types.py +++ b/scripts/qapi-types.py @@ -2,7 +2,7 @@ # QAPI types generator # # Copyright IBM, Corp. 2011 -# Copyright (c) 2013-2015 Red Hat Inc. +# Copyright (c) 2013-2016 Red Hat Inc. # # Authors: # Anthony Liguori <aliguori@us.ibm.com> @@ -14,6 +14,11 @@ from qapi import * +# variants must be emitted before their container; track what has already +# been output +objects_seen = set() + + def gen_fwd_object_or_array(name): return mcgen(''' @@ -49,11 +54,23 @@ def gen_struct_fields(members): def gen_object(name, base, members, variants): - ret = mcgen(''' + if name in objects_seen: + return '' + objects_seen.add(name) + + ret = '' + if variants: + for v in variants.variants: + if (isinstance(v.type, QAPISchemaObjectType) and + not v.type.is_implicit()): + ret += gen_object(v.type.name, v.type.base, + v.type.local_members, v.type.variants) + + ret += mcgen(''' struct %(c_name)s { ''', - c_name=c_name(name)) + c_name=c_name(name)) if base: ret += mcgen(''' |