| Message ID | 20170505201128.12099-4-ehabkost@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 05/05/2017 03:11 PM, Eduardo Habkost wrote: > 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. Stale comment, given... > > 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 <ehabkost@redhat.com> > --- > Changes v1 -> v2: > * Updated string_input_visitor_new() documentation > to mention alternate support (Markus Armbruster) > * Detect ambiguous alternates at runtime. Test case included. > * Removed support for integers. We don't need it yet, and ...this. > it would require sorting out the parse_str() mess. > * Change supported_qtypes to uint32_t (Eric Blake) > * Update tests/qapi-schema/qapi-schema-test.out to match > qapi-schema-test.json updates > (Eric Blake) > * Code indentation fix (Markus Armbruster) > * Use &error_abort on test cases instead of g_assert(!err) > (Markus Armbruster) > --- > > +/* > + * Check if alternate type string representation is ambiguous and > + * can't be parsed by StringInputVisitor > + */ > +static bool ambiguous_alternate(uint32_t qtypes, const char *const enum_table[]) > +{ > + uint32_t non_str_qtypes = qtypes & ~(1U << QTYPE_QSTRING); > + > + if ((qtypes & (1U << QTYPE_QSTRING)) && !enum_table && non_str_qtypes) { > + return true; > + } > + > + if (qtypes & (1U << QTYPE_QBOOL)) { > + const char *const *e; > + /* > + * If the string representation of enum members can be parsed as > + * booleans, the alternate string representation is ambiguous. > + */ > + for (e = enum_table; e && *e; e++) { > + if (try_parse_bool(*e, NULL) == 0) { > + return true; > + } > + } > + } > + > + return false; > +} Seems okay for detecting ambiguity, but it is a runtime cost (one that you will run every single time you parse, even though the answer will be the same every single time you run it); I still think doing it at QAPI compile time will be more efficient in the long run. And as this is the only use of enum_table added in 2/3, I'm still not sold on needing that patch. > + > +static void start_alternate(Visitor *v, const char *name, > + GenericAlternate **obj, size_t size, > + uint32_t qtypes, const char *const enum_table[], > + Error **errp) > +{ > + /* > + * Enum types are represented as QTYPE_QSTRING, so this is > + * the default. Actual parsing of the string as an enum is > + * done by visit_type_<EnumType>(), which is called just > + * after visit_start_alternate(). > + */ > + QType qtype = QTYPE_QSTRING; > + uint32_t unsupported_qtypes = qtypes & ~((1U << QTYPE_QSTRING) | > + (1U << QTYPE_QBOOL)); > + StringInputVisitor *siv = to_siv(v); > + > + if (ambiguous_alternate(qtypes, enum_table)) { > + error_setg(errp, "Can't parse ambiguous alternate type"); > + return; > + } > + > + if (unsupported_qtypes) { > + error_setg(errp, "Can't parse %s' alternate member", > + QType_lookup[ctz32(unsupported_qtypes)]); > + return; > + } > + > + if ((qtypes & (1U << QTYPE_QBOOL)) && > + try_parse_bool(siv->string, NULL) == 0) { > + qtype = QTYPE_QBOOL; > + } > + > + *obj = g_malloc0(size); > + (*obj)->type = qtype; Slightly simpler for ignoring int for now, while still something we could add in later. I've been wanting to have an alternate for 'int'/'str' for InetAddress port, since we want to support named ports but most often use just integers. On the command line, port=1 is fine, but in QMP, we currently have to spell it port="1". That's a case where we'd allow a pairing of any string with an integer, rather than just an enum.
On Fri, May 05, 2017 at 03:53:40PM -0500, Eric Blake wrote: > On 05/05/2017 03:11 PM, Eduardo Habkost wrote: > > 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. > > Stale comment, given... > > > > > 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 <ehabkost@redhat.com> > > --- > > Changes v1 -> v2: > > * Updated string_input_visitor_new() documentation > > to mention alternate support (Markus Armbruster) > > * Detect ambiguous alternates at runtime. Test case included. > > * Removed support for integers. We don't need it yet, and > > ...this. Oops. > > > it would require sorting out the parse_str() mess. > > * Change supported_qtypes to uint32_t (Eric Blake) > > * Update tests/qapi-schema/qapi-schema-test.out to match > > qapi-schema-test.json updates > > (Eric Blake) > > * Code indentation fix (Markus Armbruster) > > * Use &error_abort on test cases instead of g_assert(!err) > > (Markus Armbruster) > > --- > > > > > +/* > > + * Check if alternate type string representation is ambiguous and > > + * can't be parsed by StringInputVisitor > > + */ > > +static bool ambiguous_alternate(uint32_t qtypes, const char *const enum_table[]) > > +{ > > + uint32_t non_str_qtypes = qtypes & ~(1U << QTYPE_QSTRING); > > + > > + if ((qtypes & (1U << QTYPE_QSTRING)) && !enum_table && non_str_qtypes) { > > + return true; > > + } > > + > > + if (qtypes & (1U << QTYPE_QBOOL)) { > > + const char *const *e; > > + /* > > + * If the string representation of enum members can be parsed as > > + * booleans, the alternate string representation is ambiguous. > > + */ > > + for (e = enum_table; e && *e; e++) { > > + if (try_parse_bool(*e, NULL) == 0) { > > + return true; > > + } > > + } > > + } > > + > > + return false; > > +} > > Seems okay for detecting ambiguity, but it is a runtime cost (one that > you will run every single time you parse, even though the answer will be > the same every single time you run it); I still think doing it at QAPI > compile time will be more efficient in the long run. And as this is the > only use of enum_table added in 2/3, I'm still not sold on needing that > patch. I'm OK with deleting this part. That's the main reason I moved it to a separate function. > > > + > > +static void start_alternate(Visitor *v, const char *name, > > + GenericAlternate **obj, size_t size, > > + uint32_t qtypes, const char *const enum_table[], > > + Error **errp) > > +{ > > + /* > > + * Enum types are represented as QTYPE_QSTRING, so this is > > + * the default. Actual parsing of the string as an enum is > > + * done by visit_type_<EnumType>(), which is called just > > + * after visit_start_alternate(). > > + */ > > + QType qtype = QTYPE_QSTRING; > > + uint32_t unsupported_qtypes = qtypes & ~((1U << QTYPE_QSTRING) | > > + (1U << QTYPE_QBOOL)); > > + StringInputVisitor *siv = to_siv(v); > > + > > + if (ambiguous_alternate(qtypes, enum_table)) { > > + error_setg(errp, "Can't parse ambiguous alternate type"); > > + return; > > + } > > + > > + if (unsupported_qtypes) { > > + error_setg(errp, "Can't parse %s' alternate member", > > + QType_lookup[ctz32(unsupported_qtypes)]); > > + return; > > + } > > + > > + if ((qtypes & (1U << QTYPE_QBOOL)) && > > + try_parse_bool(siv->string, NULL) == 0) { > > + qtype = QTYPE_QBOOL; > > + } > > + > > + *obj = g_malloc0(size); > > + (*obj)->type = qtype; > > Slightly simpler for ignoring int for now, while still something we > could add in later. I've been wanting to have an alternate for > 'int'/'str' for InetAddress port, since we want to support named ports > but most often use just integers. On the command line, port=1 is fine, > but in QMP, we currently have to spell it port="1". That's a case where > we'd allow a pairing of any string with an integer, rather than just an > enum. Does that mean we already have an use case where we will have to relax the restrictions on ambiguous enums? :) I won't mind at all if we remove the runtime detection of ambiguous enums. It will make the code much simpler.
In addition to Eric's remarks: Eduardo Habkost <ehabkost@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 <ehabkost@redhat.com> > --- > Changes v1 -> v2: > * Updated string_input_visitor_new() documentation > to mention alternate support (Markus Armbruster) > * Detect ambiguous alternates at runtime. Test case included. > * Removed support for integers. We don't need it yet, and > it would require sorting out the parse_str() mess. > * Change supported_qtypes to uint32_t (Eric Blake) > * Update tests/qapi-schema/qapi-schema-test.out to match > qapi-schema-test.json updates > (Eric Blake) > * Code indentation fix (Markus Armbruster) > * Use &error_abort on test cases instead of g_assert(!err) > (Markus Armbruster) > --- > include/qapi/string-input-visitor.h | 6 +- > qapi/string-input-visitor.c | 99 +++++++++++++++++++++++++++++---- > tests/test-string-input-visitor.c | 76 +++++++++++++++++++++++++ > tests/qapi-schema/qapi-schema-test.json | 8 +++ > tests/qapi-schema/qapi-schema-test.out | 9 +++ > 5 files changed, 187 insertions(+), 11 deletions(-) > > diff --git a/include/qapi/string-input-visitor.h b/include/qapi/string-input-visitor.h > index 33551340e3..e7f359f225 100644 > --- a/include/qapi/string-input-visitor.h > +++ b/include/qapi/string-input-visitor.h > @@ -19,8 +19,12 @@ typedef struct StringInputVisitor StringInputVisitor; > > /* > * The string input visitor does not implement support for visiting > - * QAPI structs, alternates, null, or arbitrary QTypes. It also > + * QAPI structs, null, or arbitrary QTypes. It also > * requires a non-null list argument to visit_start_list(). I'd prefer to have this paragraph refilled. > + * > + * Support for alternates is very limited: only bool and enum > + * members are supported, and only when the enum members' > + * representations can't be confused with a bool value. > */ > Visitor *string_input_visitor_new(const char *str); > > diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c > index c089491c24..e339b88192 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/host-utils.h" Still needed? > > > struct StringInputVisitor [...] Skipping the rest for now. I'd like to explore restricting alternates at compile-time. If that turns out well, we can drop most of this patch.
Eduardo Habkost <ehabkost@redhat.com> writes: > On Fri, May 05, 2017 at 03:53:40PM -0500, Eric Blake wrote: [...] >> Slightly simpler for ignoring int for now, while still something we >> could add in later. I've been wanting to have an alternate for >> 'int'/'str' for InetAddress port, since we want to support named ports >> but most often use just integers. On the command line, port=1 is fine, >> but in QMP, we currently have to spell it port="1". That's a case where >> we'd allow a pairing of any string with an integer, rather than just an >> enum. > > Does that mean we already have an use case where we will have to > relax the restrictions on ambiguous enums? :) A rather weak one. Certainly too weak by itself to make me open another can of string-input-visitor worms. > I won't mind at all if we remove the runtime detection of > ambiguous enums. It will make the code much simpler. That's the idea :)
diff --git a/include/qapi/string-input-visitor.h b/include/qapi/string-input-visitor.h index 33551340e3..e7f359f225 100644 --- a/include/qapi/string-input-visitor.h +++ b/include/qapi/string-input-visitor.h @@ -19,8 +19,12 @@ typedef struct StringInputVisitor StringInputVisitor; /* * The string input visitor does not implement support for visiting - * QAPI structs, alternates, null, or arbitrary QTypes. It also + * QAPI structs, null, or arbitrary QTypes. It also * requires a non-null list argument to visit_start_list(). + * + * Support for alternates is very limited: only bool and enum + * members are supported, and only when the enum members' + * representations can't be confused with a bool value. */ Visitor *string_input_visitor_new(const char *str); diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c index c089491c24..e339b88192 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/host-utils.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 +340,70 @@ static void parse_type_number(Visitor *v, const char *name, double *obj, *obj = val; } +/* + * Check if alternate type string representation is ambiguous and + * can't be parsed by StringInputVisitor + */ +static bool ambiguous_alternate(uint32_t qtypes, const char *const enum_table[]) +{ + uint32_t non_str_qtypes = qtypes & ~(1U << QTYPE_QSTRING); + + if ((qtypes & (1U << QTYPE_QSTRING)) && !enum_table && non_str_qtypes) { + return true; + } + + if (qtypes & (1U << QTYPE_QBOOL)) { + const char *const *e; + /* + * If the string representation of enum members can be parsed as + * booleans, the alternate string representation is ambiguous. + */ + for (e = enum_table; e && *e; e++) { + if (try_parse_bool(*e, NULL) == 0) { + return true; + } + } + } + + return false; +} + +static void start_alternate(Visitor *v, const char *name, + GenericAlternate **obj, size_t size, + uint32_t qtypes, const char *const enum_table[], + Error **errp) +{ + /* + * Enum types are represented as QTYPE_QSTRING, so this is + * the default. Actual parsing of the string as an enum is + * done by visit_type_<EnumType>(), which is called just + * after visit_start_alternate(). + */ + QType qtype = QTYPE_QSTRING; + uint32_t unsupported_qtypes = qtypes & ~((1U << QTYPE_QSTRING) | + (1U << QTYPE_QBOOL)); + StringInputVisitor *siv = to_siv(v); + + if (ambiguous_alternate(qtypes, enum_table)) { + error_setg(errp, "Can't parse ambiguous alternate type"); + return; + } + + if (unsupported_qtypes) { + error_setg(errp, "Can't parse %s' alternate member", + QType_lookup[ctz32(unsupported_qtypes)]); + return; + } + + if ((qtypes & (1U << QTYPE_QBOOL)) && + try_parse_bool(siv->string, NULL) == 0) { + qtype = QTYPE_QBOOL; + } + + *obj = g_malloc0(size); + (*obj)->type = qtype; +} + static void string_input_free(Visitor *v) { StringInputVisitor *siv = to_siv(v); @@ -353,6 +431,7 @@ 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..263fcc2b8c 100644 --- a/tests/test-string-input-visitor.c +++ b/tests/test-string-input-visitor.c @@ -290,6 +290,76 @@ static void test_visitor_in_enum(TestInputVisitorData *data, } } +static void test_visitor_in_alt_bool_enum(TestInputVisitorData *data, + const void *unused) +{ + Error *err = NULL; + Visitor *v; + AltBoolEnum *be = NULL; + + v = visitor_input_test_init(data, "true"); + visit_type_AltBoolEnum(v, NULL, &be, &error_abort); + 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, &error_abort); + 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, &error_abort); + 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_ambig_str(TestInputVisitorData *data, + const void *unused) +{ + Error *err = NULL; + Visitor *v; + AltStrBool *sb = NULL; + + /* + * AltStrBool has an ambiguous string representation, and + * can't be handled by string-input-visitor: + */ + v = visitor_input_test_init(data, "s"); + visit_type_AltStrBool(v, NULL, &sb, &err); + error_free_or_abort(&err); + qapi_free_AltStrBool(sb); +} + +static void test_visitor_in_alt_ambig_enum(TestInputVisitorData *data, + const void *unused) +{ + Error *err = NULL; + Visitor *v; + AltOnOffBool *ob = NULL; + + /* + * AltOnOffBool has an ambiguous string representation, and + * can't be handled by string-input-visitor: + */ + v = visitor_input_test_init(data, "on"); + visit_type_AltOnOffBool(v, NULL, &ob, &err); + error_free_or_abort(&err); + qapi_free_AltOnOffBool(ob); +} + /* Try to crash the visitors */ static void test_visitor_in_fuzz(TestInputVisitorData *data, const void *unused) @@ -366,6 +436,12 @@ 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/ambig_enum", + &in_visitor_data, test_visitor_in_alt_ambig_enum); + input_visitor_test_add("/string-visitor/input/alternate/ambig_str", + &in_visitor_data, test_visitor_in_alt_ambig_str); 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..d602f3d40b 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: +{ 'alternate': 'AltBoolEnum', 'data': { 'b': 'bool', 'e': 'EnumOne' } } + +# this alternate type will be detected as ambiguous by string-input-visitor: +{ 'enum': 'TestOnOffAuto', + 'data': [ 'on', 'off', 'auto' ] } +{ 'alternate': 'AltOnOffBool', 'data': { 'o': 'TestOnOffAuto', 'b': 'bool' } } + # for testing native lists { 'union': 'UserDefNativeListUnion', 'data': { 'integer': ['int'], diff --git a/tests/qapi-schema/qapi-schema-test.out b/tests/qapi-schema/qapi-schema-test.out index 9d99c4eebb..17cd276295 100644 --- a/tests/qapi-schema/qapi-schema-test.out +++ b/tests/qapi-schema/qapi-schema-test.out @@ -1,3 +1,7 @@ +alternate AltBoolEnum + tag type + case b: bool + case e: EnumOne alternate AltIntNum tag type case i: int @@ -10,6 +14,10 @@ alternate AltNumStr tag type case n: number case s: str +alternate AltOnOffBool + tag type + case o: TestOnOffAuto + case b: bool alternate AltStrBool tag type case s: str @@ -56,6 +64,7 @@ enum QEnumTwo ['value1', 'value2'] prefix QENUM_TWO enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool'] prefix QTYPE +enum TestOnOffAuto ['on', 'off', 'auto'] object TestStruct member integer: int optional=False member boolean: bool optional=False
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 <ehabkost@redhat.com> --- Changes v1 -> v2: * Updated string_input_visitor_new() documentation to mention alternate support (Markus Armbruster) * Detect ambiguous alternates at runtime. Test case included. * Removed support for integers. We don't need it yet, and it would require sorting out the parse_str() mess. * Change supported_qtypes to uint32_t (Eric Blake) * Update tests/qapi-schema/qapi-schema-test.out to match qapi-schema-test.json updates (Eric Blake) * Code indentation fix (Markus Armbruster) * Use &error_abort on test cases instead of g_assert(!err) (Markus Armbruster) --- include/qapi/string-input-visitor.h | 6 +- qapi/string-input-visitor.c | 99 +++++++++++++++++++++++++++++---- tests/test-string-input-visitor.c | 76 +++++++++++++++++++++++++ tests/qapi-schema/qapi-schema-test.json | 8 +++ tests/qapi-schema/qapi-schema-test.out | 9 +++ 5 files changed, 187 insertions(+), 11 deletions(-)