From becceedc4d9bc1435099c90a0514945a89844d3a Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 17 Feb 2016 23:48:26 -0700 Subject: qapi: Don't box struct branch of alternate There's no reason to do two malloc's for an alternate type visiting a QAPI struct; let's just inline the struct directly as the C union branch of the struct. Surprisingly, no clients were actually using the struct member prior to this patch outside of the testsuite; an earlier patch in the series added some testsuite coverage to make the effect of this patch more obvious. In qapi.py, c_type() gains a new is_unboxed flag to control when we are emitting a C struct unboxed within the context of an outer struct (different from our other two modes of usage with no flags for normal local variable declarations, and with is_param for adding 'const' in a parameter list). I don't know if there is any more pythonic way of collapsing the two flags into a single parameter, as we never have a caller setting both flags at once. Ultimately, we want to also unbox branches for QAPI unions, but as that touches a lot more client code, it is better as separate patches. But since unions and alternates share gen_variants(), I had to hack in a way to test if we are visiting an alternate type for setting the is_unboxed flag: look for a non-object branch. This works because alternates have at least two branches, with at most one object branch, while unions have only object branches. The hack will go away in a later patch. The generated code difference to qapi-types.h is relatively small: | struct BlockdevRef { | QType type; | union { /* union tag is @type */ | void *data; |- BlockdevOptions *definition; |+ BlockdevOptions definition; | char *reference; | } u; | }; The corresponding spot in qapi-visit.c calls visit_type_FOO(), which first calls visit_start_struct() to allocate or deallocate the member and handle a layer of {} from the JSON stream, then visits the members. To peel off the indirection and the memory management that comes with it, we inline this call, then suppress allocation / deallocation by passing NULL to visit_start_struct(), and adjust the member visit: | switch ((*obj)->type) { | case QTYPE_QDICT: |- visit_type_BlockdevOptions(v, name, &(*obj)->u.definition, &err); |+ visit_start_struct(v, name, NULL, 0, &err); |+ if (err) { |+ break; |+ } |+ visit_type_BlockdevOptions_fields(v, &(*obj)->u.definition, &err); |+ error_propagate(errp, err); |+ err = NULL; |+ visit_end_struct(v, &err); | break; | case QTYPE_QSTRING: | visit_type_str(v, name, &(*obj)->u.reference, &err); The visit of non-object fields is unchanged. Signed-off-by: Eric Blake Message-Id: <1455778109-6278-13-git-send-email-eblake@redhat.com> [Commit message tweaked] Signed-off-by: Markus Armbruster --- tests/test-qmp-input-visitor.c | 20 ++++++++++---------- tests/test-qmp-output-visitor.c | 11 +++++------ 2 files changed, 15 insertions(+), 16 deletions(-) (limited to 'tests') diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c index ef836d5fbe..47cf6aaff0 100644 --- a/tests/test-qmp-input-visitor.c +++ b/tests/test-qmp-input-visitor.c @@ -327,11 +327,11 @@ static void test_visitor_in_alternate(TestInputVisitorData *data, "'enum1':'value1', 'boolean':true}"); visit_type_UserDefAlternate(v, NULL, &tmp, &error_abort); g_assert_cmpint(tmp->type, ==, QTYPE_QDICT); - g_assert_cmpint(tmp->u.udfu->integer, ==, 1); - g_assert_cmpstr(tmp->u.udfu->string, ==, "str"); - g_assert_cmpint(tmp->u.udfu->enum1, ==, ENUM_ONE_VALUE1); - g_assert_cmpint(tmp->u.udfu->u.value1->boolean, ==, true); - g_assert_cmpint(tmp->u.udfu->u.value1->has_a_b, ==, false); + g_assert_cmpint(tmp->u.udfu.integer, ==, 1); + g_assert_cmpstr(tmp->u.udfu.string, ==, "str"); + g_assert_cmpint(tmp->u.udfu.enum1, ==, ENUM_ONE_VALUE1); + g_assert_cmpint(tmp->u.udfu.u.value1->boolean, ==, true); + g_assert_cmpint(tmp->u.udfu.u.value1->has_a_b, ==, false); qapi_free_UserDefAlternate(tmp); v = visitor_input_test_init(data, "false"); @@ -355,11 +355,11 @@ static void test_visitor_in_alternate(TestInputVisitorData *data, "'enum1':'value1', 'boolean':true} }"); visit_type_WrapAlternate(v, NULL, &wrap, &error_abort); g_assert_cmpint(wrap->alt->type, ==, QTYPE_QDICT); - g_assert_cmpint(wrap->alt->u.udfu->integer, ==, 1); - g_assert_cmpstr(wrap->alt->u.udfu->string, ==, "str"); - g_assert_cmpint(wrap->alt->u.udfu->enum1, ==, ENUM_ONE_VALUE1); - g_assert_cmpint(wrap->alt->u.udfu->u.value1->boolean, ==, true); - g_assert_cmpint(wrap->alt->u.udfu->u.value1->has_a_b, ==, false); + g_assert_cmpint(wrap->alt->u.udfu.integer, ==, 1); + g_assert_cmpstr(wrap->alt->u.udfu.string, ==, "str"); + g_assert_cmpint(wrap->alt->u.udfu.enum1, ==, ENUM_ONE_VALUE1); + g_assert_cmpint(wrap->alt->u.udfu.u.value1->boolean, ==, true); + g_assert_cmpint(wrap->alt->u.udfu.u.value1->has_a_b, ==, false); qapi_free_WrapAlternate(wrap); } diff --git a/tests/test-qmp-output-visitor.c b/tests/test-qmp-output-visitor.c index 2b0f7e9c53..fe2f1a1326 100644 --- a/tests/test-qmp-output-visitor.c +++ b/tests/test-qmp-output-visitor.c @@ -457,12 +457,11 @@ static void test_visitor_out_alternate(TestOutputVisitorData *data, tmp = g_new0(UserDefAlternate, 1); tmp->type = QTYPE_QDICT; - tmp->u.udfu = g_new0(UserDefFlatUnion, 1); - tmp->u.udfu->integer = 1; - tmp->u.udfu->string = g_strdup("str"); - tmp->u.udfu->enum1 = ENUM_ONE_VALUE1; - tmp->u.udfu->u.value1 = g_new0(UserDefA, 1); - tmp->u.udfu->u.value1->boolean = true; + tmp->u.udfu.integer = 1; + tmp->u.udfu.string = g_strdup("str"); + tmp->u.udfu.enum1 = ENUM_ONE_VALUE1; + tmp->u.udfu.u.value1 = g_new0(UserDefA, 1); + tmp->u.udfu.u.value1->boolean = true; visit_type_UserDefAlternate(data->ov, NULL, &tmp, &error_abort); arg = qmp_output_get_qobject(data->qov); -- cgit v1.2.3-55-g7522