Commit 4dc2e690 authored by Eric Blake's avatar Eric Blake Committed by Markus Armbruster
Browse files

qapi: Better error messages for duplicated expressions 



The previous commit demonstrated that the generator overlooked
duplicate expressions:
- a complex type or command reusing a built-in type name
- redeclaration of a type name, whether by the same or different
metatype
- redeclaration of a command or event
- collision of a type with implicit 'Kind' enum for a union
- collision with an implicit MAX enum constant

Since the c_type() function in the generator treats all names
as being in the same namespace, this patch adds a global array
to track all known names and their source, to prevent collisions
before it can cause further problems.  While valid .json files
won't trigger any of these cases, we might as well be nicer to
developers that make a typo while trying to add new QAPI code.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent cfdd5bca

scripts/qapi.py

+49 −14
Original line number Diff line number Diff line
@@ -32,6 +32,12 @@ builtin_types = { 
    'size':     'QTYPE_QINT',

}



enum_types = []

struct_types = []

union_types = []

events = []

all_names = {}



def error_path(parent):

    res = ""

    while parent:
@@ -256,7 +262,14 @@ def discriminator_find_enum_define(expr): 
    return find_enum(discriminator_type)



def check_event(expr, expr_info):

    global events

    name = expr['event']

    params = expr.get('data')



    if name.upper() == 'MAX':

        raise QAPIExprError(expr_info, "Event name 'MAX' cannot be created")

    events.append(name)



    if params:

        for argname, argentry, optional, structured in parse_args(params):

            if structured:
@@ -430,6 +443,9 @@ def check_keys(expr_elem, meta, required, optional=[]): 




def parse_schema(input_file):

    global all_names

    exprs = []



    # First pass: read entire file into memory

    try:

        schema = QAPISchema(open(input_file, "r"))
@@ -437,30 +453,34 @@ def parse_schema(input_file): 
        print >>sys.stderr, e

        exit(1)



    exprs = []



    try:

        # Next pass: learn the types and check for valid expression keys. At

        # this point, top-level 'include' has already been flattened.

        for builtin in builtin_types.keys():

            all_names[builtin] = 'built-in'

        for expr_elem in schema.exprs:

            expr = expr_elem['expr']

            info = expr_elem['info']

            if expr.has_key('enum'):

                check_keys(expr_elem, 'enum', ['data'])

                add_enum(expr['enum'], expr['data'])

                add_enum(expr['enum'], info, expr['data'])

            elif expr.has_key('union'):

                check_keys(expr_elem, 'union', ['data'],

                           ['base', 'discriminator'])

                add_union(expr)

                add_union(expr, info)

            elif expr.has_key('alternate'):

                check_keys(expr_elem, 'alternate', ['data'])

                add_name(expr['alternate'], info, 'alternate')

            elif expr.has_key('type'):

                check_keys(expr_elem, 'type', ['data'], ['base'])

                add_struct(expr)

                add_struct(expr, info)

            elif expr.has_key('command'):

                check_keys(expr_elem, 'command', [],

                           ['data', 'returns', 'gen', 'success-response'])

                add_name(expr['command'], info, 'command')

            elif expr.has_key('event'):

                check_keys(expr_elem, 'event', [], ['data'])

                add_name(expr['event'], info, 'event')

            else:

                raise QAPIExprError(expr_elem['info'],

                                    "Expression is missing metatype")
@@ -471,9 +491,11 @@ def parse_schema(input_file): 
            expr = expr_elem['expr']

            if expr.has_key('union'):

                if not discriminator_find_enum_define(expr):

                    add_enum('%sKind' % expr['union'])

                    add_enum('%sKind' % expr['union'], expr_elem['info'],

                             implicit=True)

            elif expr.has_key('alternate'):

                add_enum('%sKind' % expr['alternate'])

                add_enum('%sKind' % expr['alternate'], expr_elem['info'],

                         implicit=True)



        # Final pass - validate that exprs make sense

        check_exprs(schema)
@@ -567,12 +589,22 @@ def type_name(name): 
        return c_list_type(name[0])

    return name



enum_types = []

struct_types = []

union_types = []

def add_name(name, info, meta, implicit = False):

    global all_names

    if name in all_names:

        raise QAPIExprError(info,

                            "%s '%s' is already defined"

                            % (all_names[name], name))

    if not implicit and name[-4:] == 'Kind':

        raise QAPIExprError(info,

                            "%s '%s' should not end in 'Kind'"

                            % (meta, name))

    all_names[name] = meta



def add_struct(definition):

def add_struct(definition, info):

    global struct_types

    name = definition['type']

    add_name(name, info, 'struct')

    struct_types.append(definition)



def find_struct(name):
@@ -582,8 +614,10 @@ def find_struct(name): 
            return struct

    return None



def add_union(definition):

def add_union(definition, info):

    global union_types

    name = definition['union']

    add_name(name, info, 'union')

    union_types.append(definition)



def find_union(name):
@@ -593,8 +627,9 @@ def find_union(name): 
            return union

    return None



def add_enum(name, enum_values = None):

def add_enum(name, info, enum_values = None, implicit = False):

    global enum_types

    add_name(name, info, 'enum', implicit)

    enum_types.append({"enum_name": name, "enum_values": enum_values})



def find_enum(name):
@@ -636,7 +671,7 @@ def c_type(name, is_param=False): 
        return name

    elif name == None or len(name) == 0:

        return 'void'

    elif name == name.upper():

    elif name in events:

        return '%sEvent *%s' % (camel_case(name), eatspace)

    else:

        return '%s *%s' % (name, eatspace)

tests/qapi-schema/command-int.err

+1 −0
Original line number Diff line number Diff line 
tests/qapi-schema/command-int.json:2: built-in 'int' is already defined

tests/qapi-schema/command-int.exit

+1 −1
Original line number Diff line number Diff line 
0
 
1

tests/qapi-schema/command-int.json

+1 −1
Original line number Diff line number Diff line 
# FIXME: we should reject collisions between commands and types

# we reject collisions between commands and types

{ 'command': 'int', 'data': { 'character': 'str' },

  'returns': { 'value': 'int' } }

tests/qapi-schema/command-int.out

+0 −3
Original line number Diff line number Diff line 
[OrderedDict([('command', 'int'), ('data', OrderedDict([('character', 'str')])), ('returns', OrderedDict([('value', 'int')]))])]

[]

[]