Re: [Qemu-devel] [PATCH RFC v2 24/47] tests/qapi-schema: Convert test harness to QAPISchemaVisitor

[Eric Blake]

On 07/01/2015 02:22 PM, Markus Armbruster wrote:
> The old code prints the result of parsing (list of expression
> dictionaries), and partial results of semantic analysis (list of enum
> dictionaries, list of struct dictionaries).
> 
> The new code prints a trace of a schema visit, i.e. what the back-ends
> are going to use.  Built-in and array types are omitted, because
> they're boring.
> 
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
>  tests/qapi-schema/alternate-good.out            |  15 +-
>  tests/qapi-schema/comments.out                  |   4 +-
>  tests/qapi-schema/data-member-array.out         |  13 +-
>  tests/qapi-schema/empty.out                     |   3 -
>  tests/qapi-schema/enum-empty.out                |   4 +-
>  tests/qapi-schema/event-case.out                |   4 +-
>  tests/qapi-schema/flat-union-reverse-define.out |  21 +--
>  tests/qapi-schema/ident-with-escape.out         |   7 +-
>  tests/qapi-schema/include-relpath.out           |   4 +-
>  tests/qapi-schema/include-repetition.out        |   4 +-
>  tests/qapi-schema/include-simple.out            |   4 +-
>  tests/qapi-schema/indented-expr.out             |   7 +-
>  tests/qapi-schema/qapi-schema-test.out          | 186 
> +++++++++++++++++-------
>  tests/qapi-schema/returns-int.out               |   5 +-
>  tests/qapi-schema/test-qapi.py                  |  37 ++++-
>  tests/qapi-schema/type-bypass.out               |   7 +-
>  16 files changed, 210 insertions(+), 115 deletions(-)

We have a lot more negative than positive tests of the parser (good
thing, because that meant fewer .out files to update to the new format).

No change to actual qemu code, and proves that the previous three
patches have set up enough of a framework to accurately cover our testsuite.

> 
> diff --git a/tests/qapi-schema/alternate-good.out 
> b/tests/qapi-schema/alternate-good.out
> index 99848ee..0cbdfa1 100644
> --- a/tests/qapi-schema/alternate-good.out
> +++ b/tests/qapi-schema/alternate-good.out
> @@ -1,6 +1,9 @@
> -[OrderedDict([('struct', 'Data'), ('data', OrderedDict([('*number', 'int'), 
> ('*name', 'str')]))]),
> - OrderedDict([('enum', 'Enum'), ('data', ['hello', 'world'])]),
> - OrderedDict([('alternate', 'Alt'), ('data', OrderedDict([('value', 'int'), 
> ('string', 'Enum'), ('struct', 'Data')]))])]
> -[{'enum_name': 'Enum', 'enum_values': ['hello', 'world']},
> - {'enum_name': 'AltKind', 'enum_values': None}]
> -[OrderedDict([('struct', 'Data'), ('data', OrderedDict([('*number', 'int'), 
> ('*name', 'str')]))])]
> +alternate Alt
> +    case value: int flat=False
> +    case string: Enum flat=False
> +    case struct: Data flat=False

I'm still not convinced whether we need .flat exposed through this much
detail, or if we should just normalize plain unions into flat unions
with implicit structs for each branch.  Changing your design will have
obvious ripple effects here.

> +++ b/tests/qapi-schema/data-member-array.out
> @@ -1,5 +1,8 @@
> -[OrderedDict([('enum', 'abc'), ('data', ['a', 'b', 'c'])]),
> - OrderedDict([('struct', 'def'), ('data', OrderedDict([('array', 
> ['abc'])]))]),
> - OrderedDict([('command', 'okay'), ('data', OrderedDict([('member1', 
> ['int']), ('member2', ['def'])]))])]
> -[{'enum_name': 'abc', 'enum_values': ['a', 'b', 'c']}]
> -[OrderedDict([('struct', 'def'), ('data', OrderedDict([('array', 
> ['abc'])]))])]
> +object :obj-okay-args
> +    member member1: intList optional=False

Took me a moment to realize the object is an implicit one (named
':obj-okay-args') and not a typo for 'object: obj-okay-args' consistent
with members being listed 'name: type'.  But not worth changing things,
as it is sufficiently unambiguous to serve as a valid test.

> +object UserDefFlatUnion
> +    base UserDefUnionBase
> +    tag enum1
> +    case value1: UserDefA flat=True
> +    case value2: UserDefB flat=True
> +    case value3: UserDefB flat=True
> +object UserDefFlatUnion2
> +    base UserDefUnionBase
> +    tag enum1
> +    case value1: UserDefC flat=True
> +    case value2: UserDefB flat=True
> +    case value3: UserDefA flat=True
> +object UserDefNativeListUnion
> +    case integer: intList flat=False
> +    case s8: int8List flat=False
> +    case s16: int16List flat=False
> +    case s32: int32List flat=False
> +    case s64: int64List flat=False
> +    case u8: uint8List flat=False
> +    case u16: uint16List flat=False
> +    case u32: uint32List flat=False
> +    case u64: uint64List flat=False
> +    case number: numberList flat=False
> +    case boolean: boolList flat=False
> +    case string: strList flat=False
> +    case sizes: sizeList flat=False
> +enum UserDefNativeListUnionKind ['integer', 's8', 's16', 's32', 's64', 'u8', 
> 'u16', 'u32', 'u64', 'number', 'boolean', 'string', 'sizes']

Hmm. You are dumping the tag name and type of flat unions, but not of
simple unions.  I would have expected:

object UserDefNativeListUnion
    member kind: UserDefNativeListUnionKind
    tag kind
    case integer: intList flat=False
...

The above was fallout, while below is the meat of the new visitor.

> +++ b/tests/qapi-schema/test-qapi.py
> @@ -15,11 +15,34 @@ from pprint import pprint
>  import os
>  import sys
>  
> -try:
> -    exprs = QAPISchema(sys.argv[1]).get_exprs()
> -except SystemExit:
> -    raise
> +class QAPISchemaTestVisitor(QAPISchemaVisitor):
> +    def visit_enum_type(self, name, info, values):
> +        print 'enum %s %s' % (name, values)
> +    def visit_object_type(self, name, info, base, members, variants):
> +        print 'object %s' % name
> +        if base:
> +            print '    base %s' % base.name
> +        for m in members:
> +            print '    member %s: %s optional=%s' % (m.name, m.type.name,
> +                                                     m.optional)
> +        self._print_variants(variants)

So here is where information was missing when visiting a simple union.
Why didn't 'kind' get injected into members?  And...

> +    def visit_alternate_type(self, name, info, variants):
> +        print 'alternate %s' % name
> +        self._print_variants(variants)
> +    def visit_command(self, name, info, args, rets, gen, success_response):
> +        print 'command %s %s -> %s' % (name, (args and args.name),
> +                                       (rets and rets.name))
> +        print '   gen=%s success_response=%s' % (gen, success_response)
> +    def visit_event(self, name, info, data):
> +        print 'event %s %s' % (name, data and data.name)
>  
> -pprint(exprs)
> -pprint(enum_types)
> -pprint(struct_types)
> +    @staticmethod
> +    def _print_variants(variants):
> +        if variants:
> +            if variants.tag_name:
> +                print '    tag %s' % variants.tag_name

...shouldn't a simple union report 'kind' as its tag_name?

> +            for v in variants.variants:
> +                print '    case %s: %s flat=%s' % (v.name, v.type.name, 
> v.flat)
> +
> +schema = QAPISchema(sys.argv[1])
> +schema.visit(QAPISchemaTestVisitor())
> diff --git a/tests/qapi-schema/type-bypass.out 
> b/tests/qapi-schema/type-bypass.out

Overall, fairly slick, but I have enough questions about the
representation of a simple union that I'll wait for the non-RFC respin
to see if you change any design.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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