On Wed, May 03, 2017 at 06:07:43PM +0200, Markus Armbruster wrote:
> Eduardo Habkost <ehabk...@redhat.com> writes:
>
> > When parsing alternates from a string, there are some limitations in
> > what we can do, but it is a valid use case in some situations. We can
> > support booleans, integer types, and enums.
> >
> > This will be used to support 'feature=force' in -cpu options, while
> > keeping 'feature=on|off|true|false' represented as boolean values.
> >
> > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> > ---
> > qapi/string-input-visitor.c | 71 ++++++++++++++++++++++----
> > tests/test-string-input-visitor.c | 89
> > +++++++++++++++++++++++++++++++++
> > tests/qapi-schema/qapi-schema-test.json | 8 +++
> > 3 files changed, 158 insertions(+), 10 deletions(-)
> >
> > diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
> > index c089491c24..bf8f58748b 100644
> > --- a/qapi/string-input-visitor.c
> > +++ b/qapi/string-input-visitor.c
> > @@ -19,6 +19,7 @@
> > #include "qemu/option.h"
> > #include "qemu/queue.h"
> > #include "qemu/range.h"
> > +#include "qemu/bitops.h"
> >
> >
> > struct StringInputVisitor
> > @@ -278,21 +279,34 @@ static void parse_type_size(Visitor *v, const char
> > *name, uint64_t *obj,
> > *obj = val;
> > }
> >
> > +static int try_parse_bool(const char *s, bool *result)
> > +{
> > + if (!strcasecmp(s, "on") ||
> > + !strcasecmp(s, "yes") ||
> > + !strcasecmp(s, "true")) {
> > + if (result) {
> > + *result = true;
> > + }
> > + return 0;
> > + }
> > + if (!strcasecmp(s, "off") ||
> > + !strcasecmp(s, "no") ||
> > + !strcasecmp(s, "false")) {
> > + if (result) {
> > + *result = false;
> > + }
> > + return 0;
> > + }
> > +
> > + return -1;
> > +}
> > +
> > static void parse_type_bool(Visitor *v, const char *name, bool *obj,
> > Error **errp)
> > {
> > StringInputVisitor *siv = to_siv(v);
> >
> > - if (!strcasecmp(siv->string, "on") ||
> > - !strcasecmp(siv->string, "yes") ||
> > - !strcasecmp(siv->string, "true")) {
> > - *obj = true;
> > - return;
> > - }
> > - if (!strcasecmp(siv->string, "off") ||
> > - !strcasecmp(siv->string, "no") ||
> > - !strcasecmp(siv->string, "false")) {
> > - *obj = false;
> > + if (try_parse_bool(siv->string, obj) == 0) {
> > return;
> > }
> >
> > @@ -326,6 +340,42 @@ static void parse_type_number(Visitor *v, const char
> > *name, double *obj,
> > *obj = val;
> > }
> >
> > +/* Support for alternates on string-input-visitor is limited, because
>
> Please wing both ends of your comments, like this:
>
> /*
> * Comment text
> */
Will do.
>
> > + * the input string doesn't have any type information.
> > + *
> > + * Supported alternate member types:
> > + * 1) enums
> > + * 2) integer types
>
> Better add "(but only if there 's no enum member consisting only of
> digits)".
Oh, I didn't know this was possible.
>
> > + * 3) booleans (but only if the there's no enum variant
>
> Make that "(but only if there's no enum member".
Will do.
>
> > + * containing "on", "off", "true", or "false" as members)
>
> Begs the question what happens when you violate these restrictions.
Right now, we don't detect those cases and behavior is undefined.
I think it will be a good idea to give start_alternate() enough
information to detect those cases (by adding a 'const char *const
enum_table[]' parameter).
>
> > + *
> > + * UNSUPPORTED alternate member types:
> > + * 1) strings
> > + * 2) complex types
> > + */
>
> This comment explains the visitor's restrictions for alternate types.
> It does not explain how the function works. The proper place for
> explaining the visitor's restriction is the comment in
> string-input-visitor.h, which you need to update anyway, because right
> now it claims visiting alternates isn't implemented.
Right. I will take a look.
>
> > +static void start_alternate(Visitor *v, const char *name,
> > + GenericAlternate **obj, size_t size,
> > + unsigned long supported_qtypes, Error **errp)
> > +{
> > + StringInputVisitor *siv = to_siv(v);
> > + QType t = QTYPE_QSTRING;
>
> We usually call such variables @type or @qtype.
I will change it.
>
> QTYPE_QSTRING means enum here. Worth a comment, I think.
I will update it.
>
> > +
> > + if (supported_qtypes & BIT(QTYPE_QBOOL)) {
> > + if (try_parse_bool(siv->string, NULL) == 0) {
> > + t = QTYPE_QBOOL;
> > + }
> > + }
> > +
> > + if (supported_qtypes & BIT(QTYPE_QINT)) {
> > + if (parse_str(siv, name, NULL) == 0) {
>
> parse_str() alters *siv. Why is that harmless?
I remember concluding it was harmless, but I don't remember the
details.
I will probably drop support for integers in the next version,
and let whoever needs integer member support on alternates fix
parse_str().
>
> Aside: parse_str() is basically horrible, but that's not your fault.
That's an understatement. :)
>
> > + t = QTYPE_QINT;
> > + }
> > + }
> > +
> > + *obj = g_malloc0(size);
> > + (*obj)->type = t;
> > +}
> > +
> > static void string_input_free(Visitor *v)
> > {
> > StringInputVisitor *siv = to_siv(v);
> > @@ -353,6 +403,7 @@ Visitor *string_input_visitor_new(const char *str)
> > v->visitor.next_list = next_list;
> > v->visitor.check_list = check_list;
> > v->visitor.end_list = end_list;
> > + v->visitor.start_alternate = start_alternate;
> > v->visitor.free = string_input_free;
> >
> > v->string = str;
> > diff --git a/tests/test-string-input-visitor.c
> > b/tests/test-string-input-visitor.c
> > index 79313a7f7a..1e867d62c9 100644
> > --- a/tests/test-string-input-visitor.c
> > +++ b/tests/test-string-input-visitor.c
> > @@ -290,6 +290,91 @@ static void test_visitor_in_enum(TestInputVisitorData
> > *data,
> > }
> > }
> >
> > +static void test_visitor_in_alt_bool_enum(TestInputVisitorData *data,
> > + const void *unused)
>
> Indentation's off.
Will fix it.
>
> > +{
> > + Error *err = NULL;
> > + Visitor *v;
> > + AltBoolEnum *be = NULL;
> > +
> > + v = visitor_input_test_init(data, "true");
> > + visit_type_AltBoolEnum(v, NULL, &be, &err);
> > + g_assert(!err);
>
> What's wrong with &error_abort? More of the same below.
Most test cases in test-string-input-visitor.c use
g_asserto(!err) instead of error_abort.
I prefer the former, because I read &error_abort as "if this
causes an error, something is wrong with the caller [the test
code itself]", and g_assert(!err) as "if this assert is
triggered, the test code detected a bug".
Also, if that function call returns an error, I want to know
which line on which test case failed. &error_abort would hide
that information.
>
> > + g_assert_cmpint(be->type, ==, QTYPE_QBOOL);
> > + g_assert(be->u.b);
> > + qapi_free_AltBoolEnum(be);
> > +
> > + v = visitor_input_test_init(data, "off");
> > + visit_type_AltBoolEnum(v, NULL, &be, &err);
> > + g_assert(!err);
> > + g_assert_cmpint(be->type, ==, QTYPE_QBOOL);
> > + g_assert(!be->u.b);
> > + qapi_free_AltBoolEnum(be);
> > +
> > + v = visitor_input_test_init(data, "value2");
> > + visit_type_AltBoolEnum(v, NULL, &be, &err);
> > + g_assert(!err);
> > + g_assert_cmpint(be->type, ==, QTYPE_QSTRING);
> > + g_assert_cmpint(be->u.e, ==, ENUM_ONE_VALUE2);
> > + qapi_free_AltBoolEnum(be);
> > +
> > + v = visitor_input_test_init(data, "value100");
> > + visit_type_AltBoolEnum(v, NULL, &be, &err);
> > + error_free_or_abort(&err);
> > + qapi_free_AltBoolEnum(be);
> > +
> > + v = visitor_input_test_init(data, "10");
> > + visit_type_AltBoolEnum(v, NULL, &be, &err);
> > + error_free_or_abort(&err);
> > + qapi_free_AltBoolEnum(be);
> > +}
> > +
> > +static void test_visitor_in_alt_enum_int(TestInputVisitorData *data,
> > + const void *unused)
>
> Indentation's off.
Will fix it.
>
> > +{
> > + Error *err = NULL;
> > + Visitor *v;
> > + AltOnOffInt *be = NULL;
> > +
> > + v = visitor_input_test_init(data, "on");
> > + visit_type_AltOnOffInt(v, NULL, &be, &err);
> > + g_assert(!err);
> > + g_assert_cmpint(be->type, ==, QTYPE_QSTRING);
> > + g_assert_cmpint(be->u.o, ==, TEST_ON_OFF_AUTO_ON);
> > + qapi_free_AltOnOffInt(be);
> > +
> > + v = visitor_input_test_init(data, "off");
> > + visit_type_AltOnOffInt(v, NULL, &be, &err);
> > + g_assert(!err);
> > + g_assert_cmpint(be->type, ==, QTYPE_QSTRING);
> > + g_assert_cmpint(be->u.o, ==, TEST_ON_OFF_AUTO_OFF);
> > + qapi_free_AltOnOffInt(be);
> > +
> > + v = visitor_input_test_init(data, "auto");
> > + visit_type_AltOnOffInt(v, NULL, &be, &err);
> > + g_assert(!err);
> > + g_assert_cmpint(be->type, ==, QTYPE_QSTRING);
> > + g_assert_cmpint(be->u.o, ==, TEST_ON_OFF_AUTO_AUTO);
> > + qapi_free_AltOnOffInt(be);
> > +
> > + v = visitor_input_test_init(data, "-12345");
> > + visit_type_AltOnOffInt(v, NULL, &be, &err);
> > + g_assert(!err);
> > + g_assert_cmpint(be->type, ==, QTYPE_QINT);
> > + g_assert_cmpint(be->u.i, ==, -12345);
> > + qapi_free_AltOnOffInt(be);
> > +
> > + v = visitor_input_test_init(data, "true");
> > + visit_type_AltOnOffInt(v, NULL, &be, &err);
> > + error_free_or_abort(&err);
> > + qapi_free_AltOnOffInt(be);
> > +
> > + v = visitor_input_test_init(data, "value2");
> > + visit_type_AltOnOffInt(v, NULL, &be, &err);
> > + error_free_or_abort(&err);
> > + qapi_free_AltOnOffInt(be);
> > +}
> > +
>
> Could we use tests covering alternates that don't satisfy the string
> visitor's restrictions? Like OnOffAuto + bool.
We could, but right now the visitor is unable to detect those
cases, so behavior is undefined. I will try to address that in
the next version.
>
> > /* Try to crash the visitors */
> > static void test_visitor_in_fuzz(TestInputVisitorData *data,
> > const void *unused)
> > @@ -366,6 +451,10 @@ int main(int argc, char **argv)
> > &in_visitor_data, test_visitor_in_string);
> > input_visitor_test_add("/string-visitor/input/enum",
> > &in_visitor_data, test_visitor_in_enum);
> > + input_visitor_test_add("/string-visitor/input/alternate/bool_enum",
> > + &in_visitor_data,
> > test_visitor_in_alt_bool_enum);
> > + input_visitor_test_add("/string-visitor/input/alternate/enum_int",
> > + &in_visitor_data,
> > test_visitor_in_alt_enum_int);
> > input_visitor_test_add("/string-visitor/input/fuzz",
> > &in_visitor_data, test_visitor_in_fuzz);
> >
> > diff --git a/tests/qapi-schema/qapi-schema-test.json
> > b/tests/qapi-schema/qapi-schema-test.json
> > index 842ea3c5e3..231c8952e8 100644
> > --- a/tests/qapi-schema/qapi-schema-test.json
> > +++ b/tests/qapi-schema/qapi-schema-test.json
> > @@ -106,6 +106,14 @@
> > { 'alternate': 'AltIntNum', 'data': { 'i': 'int', 'n': 'number' } }
> > { 'alternate': 'AltNumInt', 'data': { 'n': 'number', 'i': 'int' } }
> >
> > +
> > +# for testing string-input-visitor handling of alternates:
> > +{ 'enum': 'TestOnOffAuto',
> > + 'data': [ 'on', 'off', 'auto' ] }
> > +
> > +{ 'alternate': 'AltBoolEnum', 'data': { 'b': 'bool', 'e': 'EnumOne' } }
> > +{ 'alternate': 'AltOnOffInt', 'data': { 'o': 'TestOnOffAuto', 'i': 'int' }
> > }
> > +
> > # for testing native lists
> > { 'union': 'UserDefNativeListUnion',
> > 'data': { 'integer': ['int'],
--
Eduardo
