qemu/scripts/qapi.py
Eric Blake 0545f6b887 qapi: Better error messages for bad expressions
The previous commit demonstrated that the generator overlooked some
fairly basic broken expressions:
- missing metataype
- metatype key has a non-string value
- unknown key in relation to the metatype
- conflicting metatype (this patch treats the second metatype as an
unknown key of the first key visited, which is not necessarily the
first key the user typed)

Add check_keys to cover these situations, and update testcases to
match.  A couple other tests (enum-missing-data, indented-expr) had
to change since the validation added here occurs so early.
Conversely, changes to ident-with-escape results show that we still
have problems where our handling of escape sequences differs from
true JSON, which will matter down the road if we allow arbitrary
default string values for optional parameters (but for now is not
too bad, as we currently can avoid unicode escaping as we don't
need to represent anything beyond C identifier material).

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: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-05-05 18:39:01 +02:00

726 lines
25 KiB
Python

#
# QAPI helper library
#
# Copyright IBM, Corp. 2011
# Copyright (c) 2013-2015 Red Hat Inc.
#
# Authors:
# Anthony Liguori <aliguori@us.ibm.com>
# Markus Armbruster <armbru@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2.
# See the COPYING file in the top-level directory.
import re
from ordereddict import OrderedDict
import os
import sys
builtin_types = {
'str': 'QTYPE_QSTRING',
'int': 'QTYPE_QINT',
'number': 'QTYPE_QFLOAT',
'bool': 'QTYPE_QBOOL',
'int8': 'QTYPE_QINT',
'int16': 'QTYPE_QINT',
'int32': 'QTYPE_QINT',
'int64': 'QTYPE_QINT',
'uint8': 'QTYPE_QINT',
'uint16': 'QTYPE_QINT',
'uint32': 'QTYPE_QINT',
'uint64': 'QTYPE_QINT',
'size': 'QTYPE_QINT',
}
def error_path(parent):
res = ""
while parent:
res = ("In file included from %s:%d:\n" % (parent['file'],
parent['line'])) + res
parent = parent['parent']
return res
class QAPISchemaError(Exception):
def __init__(self, schema, msg):
self.input_file = schema.input_file
self.msg = msg
self.col = 1
self.line = schema.line
for ch in schema.src[schema.line_pos:schema.pos]:
if ch == '\t':
self.col = (self.col + 7) % 8 + 1
else:
self.col += 1
self.info = schema.parent_info
def __str__(self):
return error_path(self.info) + \
"%s:%d:%d: %s" % (self.input_file, self.line, self.col, self.msg)
class QAPIExprError(Exception):
def __init__(self, expr_info, msg):
self.info = expr_info
self.msg = msg
def __str__(self):
return error_path(self.info['parent']) + \
"%s:%d: %s" % (self.info['file'], self.info['line'], self.msg)
class QAPISchema:
def __init__(self, fp, input_relname=None, include_hist=[],
previously_included=[], parent_info=None):
""" include_hist is a stack used to detect inclusion cycles
previously_included is a global state used to avoid multiple
inclusions of the same file"""
input_fname = os.path.abspath(fp.name)
if input_relname is None:
input_relname = fp.name
self.input_dir = os.path.dirname(input_fname)
self.input_file = input_relname
self.include_hist = include_hist + [(input_relname, input_fname)]
previously_included.append(input_fname)
self.parent_info = parent_info
self.src = fp.read()
if self.src == '' or self.src[-1] != '\n':
self.src += '\n'
self.cursor = 0
self.line = 1
self.line_pos = 0
self.exprs = []
self.accept()
while self.tok != None:
expr_info = {'file': input_relname, 'line': self.line, 'parent': self.parent_info}
expr = self.get_expr(False)
if isinstance(expr, dict) and "include" in expr:
if len(expr) != 1:
raise QAPIExprError(expr_info, "Invalid 'include' directive")
include = expr["include"]
if not isinstance(include, str):
raise QAPIExprError(expr_info,
'Expected a file name (string), got: %s'
% include)
include_path = os.path.join(self.input_dir, include)
for elem in self.include_hist:
if include_path == elem[1]:
raise QAPIExprError(expr_info, "Inclusion loop for %s"
% include)
# skip multiple include of the same file
if include_path in previously_included:
continue
try:
fobj = open(include_path, 'r')
except IOError, e:
raise QAPIExprError(expr_info,
'%s: %s' % (e.strerror, include))
exprs_include = QAPISchema(fobj, include, self.include_hist,
previously_included, expr_info)
self.exprs.extend(exprs_include.exprs)
else:
expr_elem = {'expr': expr,
'info': expr_info}
self.exprs.append(expr_elem)
def accept(self):
while True:
self.tok = self.src[self.cursor]
self.pos = self.cursor
self.cursor += 1
self.val = None
if self.tok == '#':
self.cursor = self.src.find('\n', self.cursor)
elif self.tok in ['{', '}', ':', ',', '[', ']']:
return
elif self.tok == "'":
string = ''
esc = False
while True:
ch = self.src[self.cursor]
self.cursor += 1
if ch == '\n':
raise QAPISchemaError(self,
'Missing terminating "\'"')
if esc:
string += ch
esc = False
elif ch == "\\":
esc = True
elif ch == "'":
self.val = string
return
else:
string += ch
elif self.tok == '\n':
if self.cursor == len(self.src):
self.tok = None
return
self.line += 1
self.line_pos = self.cursor
elif not self.tok.isspace():
raise QAPISchemaError(self, 'Stray "%s"' % self.tok)
def get_members(self):
expr = OrderedDict()
if self.tok == '}':
self.accept()
return expr
if self.tok != "'":
raise QAPISchemaError(self, 'Expected string or "}"')
while True:
key = self.val
self.accept()
if self.tok != ':':
raise QAPISchemaError(self, 'Expected ":"')
self.accept()
if key in expr:
raise QAPISchemaError(self, 'Duplicate key "%s"' % key)
expr[key] = self.get_expr(True)
if self.tok == '}':
self.accept()
return expr
if self.tok != ',':
raise QAPISchemaError(self, 'Expected "," or "}"')
self.accept()
if self.tok != "'":
raise QAPISchemaError(self, 'Expected string')
def get_values(self):
expr = []
if self.tok == ']':
self.accept()
return expr
if not self.tok in [ '{', '[', "'" ]:
raise QAPISchemaError(self, 'Expected "{", "[", "]" or string')
while True:
expr.append(self.get_expr(True))
if self.tok == ']':
self.accept()
return expr
if self.tok != ',':
raise QAPISchemaError(self, 'Expected "," or "]"')
self.accept()
def get_expr(self, nested):
if self.tok != '{' and not nested:
raise QAPISchemaError(self, 'Expected "{"')
if self.tok == '{':
self.accept()
expr = self.get_members()
elif self.tok == '[':
self.accept()
expr = self.get_values()
elif self.tok == "'":
expr = self.val
self.accept()
else:
raise QAPISchemaError(self, 'Expected "{", "[" or string')
return expr
def find_base_fields(base):
base_struct_define = find_struct(base)
if not base_struct_define:
return None
return base_struct_define['data']
# Return the qtype of an alternate branch, or None on error.
def find_alternate_member_qtype(qapi_type):
if builtin_types.has_key(qapi_type):
return builtin_types[qapi_type]
elif find_struct(qapi_type):
return "QTYPE_QDICT"
elif find_enum(qapi_type):
return "QTYPE_QSTRING"
elif find_union(qapi_type):
return "QTYPE_QDICT"
return None
# Return the discriminator enum define if discriminator is specified as an
# enum type, otherwise return None.
def discriminator_find_enum_define(expr):
base = expr.get('base')
discriminator = expr.get('discriminator')
if not (discriminator and base):
return None
base_fields = find_base_fields(base)
if not base_fields:
return None
discriminator_type = base_fields.get(discriminator)
if not discriminator_type:
return None
return find_enum(discriminator_type)
def check_event(expr, expr_info):
params = expr.get('data')
if params:
for argname, argentry, optional, structured in parse_args(params):
if structured:
raise QAPIExprError(expr_info,
"Nested structure define in event is not "
"supported, event '%s', argname '%s'"
% (expr['event'], argname))
def check_union(expr, expr_info):
name = expr['union']
base = expr.get('base')
discriminator = expr.get('discriminator')
members = expr['data']
values = { 'MAX': '(automatic)' }
# If the object has a member 'base', its value must name a complex type,
# and there must be a discriminator.
if base is not None:
if discriminator is None:
raise QAPIExprError(expr_info,
"Union '%s' requires a discriminator to go "
"along with base" %name)
# Two types of unions, determined by discriminator.
# With no discriminator it is a simple union.
if discriminator is None:
enum_define = None
if base is not None:
raise QAPIExprError(expr_info,
"Simple union '%s' must not have a base"
% name)
# Else, it's a flat union.
else:
# The object must have a string member 'base'.
if not isinstance(base, str):
raise QAPIExprError(expr_info,
"Flat union '%s' must have a string base field"
% name)
base_fields = find_base_fields(base)
if not base_fields:
raise QAPIExprError(expr_info,
"Base '%s' is not a valid type"
% base)
# The value of member 'discriminator' must name a member of the
# base type.
if not isinstance(discriminator, str):
raise QAPIExprError(expr_info,
"Flat union '%s' discriminator must be a string"
% name)
discriminator_type = base_fields.get(discriminator)
if not discriminator_type:
raise QAPIExprError(expr_info,
"Discriminator '%s' is not a member of base "
"type '%s'"
% (discriminator, base))
enum_define = find_enum(discriminator_type)
# Do not allow string discriminator
if not enum_define:
raise QAPIExprError(expr_info,
"Discriminator '%s' must be of enumeration "
"type" % discriminator)
# Check every branch
for (key, value) in members.items():
# If the discriminator names an enum type, then all members
# of 'data' must also be members of the enum type.
if enum_define:
if not key in enum_define['enum_values']:
raise QAPIExprError(expr_info,
"Discriminator value '%s' is not found in "
"enum '%s'" %
(key, enum_define["enum_name"]))
# Otherwise, check for conflicts in the generated enum
else:
c_key = _generate_enum_string(key)
if c_key in values:
raise QAPIExprError(expr_info,
"Union '%s' member '%s' clashes with '%s'"
% (name, key, values[c_key]))
values[c_key] = key
def check_alternate(expr, expr_info):
name = expr['alternate']
members = expr['data']
values = { 'MAX': '(automatic)' }
types_seen = {}
# Check every branch
for (key, value) in members.items():
# Check for conflicts in the generated enum
c_key = _generate_enum_string(key)
if c_key in values:
raise QAPIExprError(expr_info,
"Alternate '%s' member '%s' clashes with '%s'"
% (name, key, values[c_key]))
values[c_key] = key
# Ensure alternates have no type conflicts.
if isinstance(value, list):
raise QAPIExprError(expr_info,
"Alternate '%s' member '%s' must "
"not be array type" % (name, key))
qtype = find_alternate_member_qtype(value)
if not qtype:
raise QAPIExprError(expr_info,
"Alternate '%s' member '%s' has "
"invalid type '%s'" % (name, key, value))
if qtype in types_seen:
raise QAPIExprError(expr_info,
"Alternate '%s' member '%s' can't "
"be distinguished from member '%s'"
% (name, key, types_seen[qtype]))
types_seen[qtype] = key
def check_enum(expr, expr_info):
name = expr['enum']
members = expr.get('data')
values = { 'MAX': '(automatic)' }
if not isinstance(members, list):
raise QAPIExprError(expr_info,
"Enum '%s' requires an array for 'data'" % name)
for member in members:
if not isinstance(member, str):
raise QAPIExprError(expr_info,
"Enum '%s' member '%s' is not a string"
% (name, member))
key = _generate_enum_string(member)
if key in values:
raise QAPIExprError(expr_info,
"Enum '%s' member '%s' clashes with '%s'"
% (name, member, values[key]))
values[key] = member
def check_exprs(schema):
for expr_elem in schema.exprs:
expr = expr_elem['expr']
info = expr_elem['info']
if expr.has_key('enum'):
check_enum(expr, info)
elif expr.has_key('union'):
check_union(expr, info)
elif expr.has_key('alternate'):
check_alternate(expr, info)
elif expr.has_key('event'):
check_event(expr, info)
def check_keys(expr_elem, meta, required, optional=[]):
expr = expr_elem['expr']
info = expr_elem['info']
name = expr[meta]
if not isinstance(name, str):
raise QAPIExprError(info,
"'%s' key must have a string value" % meta)
required = required + [ meta ]
for (key, value) in expr.items():
if not key in required and not key in optional:
raise QAPIExprError(info,
"Unknown key '%s' in %s '%s'"
% (key, meta, name))
for key in required:
if not expr.has_key(key):
raise QAPIExprError(info,
"Key '%s' is missing from %s '%s'"
% (key, meta, name))
def parse_schema(input_file):
# First pass: read entire file into memory
try:
schema = QAPISchema(open(input_file, "r"))
except (QAPISchemaError, QAPIExprError), e:
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 expr_elem in schema.exprs:
expr = expr_elem['expr']
if expr.has_key('enum'):
check_keys(expr_elem, 'enum', ['data'])
add_enum(expr['enum'], expr['data'])
elif expr.has_key('union'):
check_keys(expr_elem, 'union', ['data'],
['base', 'discriminator'])
add_union(expr)
elif expr.has_key('alternate'):
check_keys(expr_elem, 'alternate', ['data'])
elif expr.has_key('type'):
check_keys(expr_elem, 'type', ['data'], ['base'])
add_struct(expr)
elif expr.has_key('command'):
check_keys(expr_elem, 'command', [],
['data', 'returns', 'gen', 'success-response'])
elif expr.has_key('event'):
check_keys(expr_elem, 'event', [], ['data'])
else:
raise QAPIExprError(expr_elem['info'],
"Expression is missing metatype")
exprs.append(expr)
# Try again for hidden UnionKind enum
for expr_elem in schema.exprs:
expr = expr_elem['expr']
if expr.has_key('union'):
if not discriminator_find_enum_define(expr):
add_enum('%sKind' % expr['union'])
elif expr.has_key('alternate'):
add_enum('%sKind' % expr['alternate'])
# Final pass - validate that exprs make sense
check_exprs(schema)
except QAPIExprError, e:
print >>sys.stderr, e
exit(1)
return exprs
def parse_args(typeinfo):
if isinstance(typeinfo, str):
struct = find_struct(typeinfo)
assert struct != None
typeinfo = struct['data']
for member in typeinfo:
argname = member
argentry = typeinfo[member]
optional = False
structured = False
if member.startswith('*'):
argname = member[1:]
optional = True
if isinstance(argentry, OrderedDict):
structured = True
yield (argname, argentry, optional, structured)
def de_camel_case(name):
new_name = ''
for ch in name:
if ch.isupper() and new_name:
new_name += '_'
if ch == '-':
new_name += '_'
else:
new_name += ch.lower()
return new_name
def camel_case(name):
new_name = ''
first = True
for ch in name:
if ch in ['_', '-']:
first = True
elif first:
new_name += ch.upper()
first = False
else:
new_name += ch.lower()
return new_name
def c_var(name, protect=True):
# ANSI X3J11/88-090, 3.1.1
c89_words = set(['auto', 'break', 'case', 'char', 'const', 'continue',
'default', 'do', 'double', 'else', 'enum', 'extern', 'float',
'for', 'goto', 'if', 'int', 'long', 'register', 'return',
'short', 'signed', 'sizeof', 'static', 'struct', 'switch',
'typedef', 'union', 'unsigned', 'void', 'volatile', 'while'])
# ISO/IEC 9899:1999, 6.4.1
c99_words = set(['inline', 'restrict', '_Bool', '_Complex', '_Imaginary'])
# ISO/IEC 9899:2011, 6.4.1
c11_words = set(['_Alignas', '_Alignof', '_Atomic', '_Generic', '_Noreturn',
'_Static_assert', '_Thread_local'])
# GCC http://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/C-Extensions.html
# excluding _.*
gcc_words = set(['asm', 'typeof'])
# C++ ISO/IEC 14882:2003 2.11
cpp_words = set(['bool', 'catch', 'class', 'const_cast', 'delete',
'dynamic_cast', 'explicit', 'false', 'friend', 'mutable',
'namespace', 'new', 'operator', 'private', 'protected',
'public', 'reinterpret_cast', 'static_cast', 'template',
'this', 'throw', 'true', 'try', 'typeid', 'typename',
'using', 'virtual', 'wchar_t',
# alternative representations
'and', 'and_eq', 'bitand', 'bitor', 'compl', 'not',
'not_eq', 'or', 'or_eq', 'xor', 'xor_eq'])
# namespace pollution:
polluted_words = set(['unix', 'errno'])
if protect and (name in c89_words | c99_words | c11_words | gcc_words | cpp_words | polluted_words):
return "q_" + name
return name.replace('-', '_').lstrip("*")
def c_fun(name, protect=True):
return c_var(name, protect).replace('.', '_')
def c_list_type(name):
return '%sList' % name
def type_name(name):
if type(name) == list:
return c_list_type(name[0])
return name
enum_types = []
struct_types = []
union_types = []
def add_struct(definition):
global struct_types
struct_types.append(definition)
def find_struct(name):
global struct_types
for struct in struct_types:
if struct['type'] == name:
return struct
return None
def add_union(definition):
global union_types
union_types.append(definition)
def find_union(name):
global union_types
for union in union_types:
if union['union'] == name:
return union
return None
def add_enum(name, enum_values = None):
global enum_types
enum_types.append({"enum_name": name, "enum_values": enum_values})
def find_enum(name):
global enum_types
for enum in enum_types:
if enum['enum_name'] == name:
return enum
return None
def is_enum(name):
return find_enum(name) != None
eatspace = '\033EATSPACE.'
# A special suffix is added in c_type() for pointer types, and it's
# stripped in mcgen(). So please notice this when you check the return
# value of c_type() outside mcgen().
def c_type(name, is_param=False):
if name == 'str':
if is_param:
return 'const char *' + eatspace
return 'char *' + eatspace
elif name == 'int':
return 'int64_t'
elif (name == 'int8' or name == 'int16' or name == 'int32' or
name == 'int64' or name == 'uint8' or name == 'uint16' or
name == 'uint32' or name == 'uint64'):
return name + '_t'
elif name == 'size':
return 'uint64_t'
elif name == 'bool':
return 'bool'
elif name == 'number':
return 'double'
elif type(name) == list:
return '%s *%s' % (c_list_type(name[0]), eatspace)
elif is_enum(name):
return name
elif name == None or len(name) == 0:
return 'void'
elif name == name.upper():
return '%sEvent *%s' % (camel_case(name), eatspace)
else:
return '%s *%s' % (name, eatspace)
def is_c_ptr(name):
suffix = "*" + eatspace
return c_type(name).endswith(suffix)
def genindent(count):
ret = ""
for i in range(count):
ret += " "
return ret
indent_level = 0
def push_indent(indent_amount=4):
global indent_level
indent_level += indent_amount
def pop_indent(indent_amount=4):
global indent_level
indent_level -= indent_amount
def cgen(code, **kwds):
indent = genindent(indent_level)
lines = code.split('\n')
lines = map(lambda x: indent + x, lines)
return '\n'.join(lines) % kwds + '\n'
def mcgen(code, **kwds):
raw = cgen('\n'.join(code.split('\n')[1:-1]), **kwds)
return re.sub(re.escape(eatspace) + ' *', '', raw)
def basename(filename):
return filename.split("/")[-1]
def guardname(filename):
guard = basename(filename).rsplit(".", 1)[0]
for substr in [".", " ", "-"]:
guard = guard.replace(substr, "_")
return guard.upper() + '_H'
def guardstart(name):
return mcgen('''
#ifndef %(name)s
#define %(name)s
''',
name=guardname(name))
def guardend(name):
return mcgen('''
#endif /* %(name)s */
''',
name=guardname(name))
# ENUMName -> ENUM_NAME, EnumName1 -> ENUM_NAME1
# ENUM_NAME -> ENUM_NAME, ENUM_NAME1 -> ENUM_NAME1, ENUM_Name2 -> ENUM_NAME2
# ENUM24_Name -> ENUM24_NAME
def _generate_enum_string(value):
c_fun_str = c_fun(value, False)
if value.isupper():
return c_fun_str
new_name = ''
l = len(c_fun_str)
for i in range(l):
c = c_fun_str[i]
# When c is upper and no "_" appears before, do more checks
if c.isupper() and (i > 0) and c_fun_str[i - 1] != "_":
# Case 1: next string is lower
# Case 2: previous string is digit
if (i < (l - 1) and c_fun_str[i + 1].islower()) or \
c_fun_str[i - 1].isdigit():
new_name += '_'
new_name += c
return new_name.lstrip('_').upper()
def generate_enum_full_value(enum_name, enum_value):
abbrev_string = _generate_enum_string(enum_name)
value_string = _generate_enum_string(enum_value)
return "%s_%s" % (abbrev_string, value_string)