qemu/scripts/qapi.py
Markus Armbruster c7a3f25200 qapi.py: Restructure lexer and parser
The parser has a rather unorthodox structure:

    Until EOF:

        Read a section:

            Generator function get_expr() yields one section after the
            other, as a string.  An unindented, non-empty line that
            isn't a comment starts a new section.

        Lexing:

            Split section into a list of tokens (strings), with help
            of generator function tokenize().

        Parsing:

            Parse the first expression from the list of tokens, with
            parse(), throw away any remaining tokens.

            In parse_schema(): record value of an enum, union or
            struct key (if any) in the appropriate global table,
            append expression to the list of expressions.

    Return list of expressions.

Known issues:

(1) Indentation is significant, unlike in real JSON.

(2) Neither lexer nor parser have any idea of source positions.  Error
    reporting is hard, let's go shopping.

(3) The one error we bother to detect, we "report" via raise.

(4) The lexer silently ignores invalid characters.

(5) If everything in a section gets ignored, the parser crashes.

(6) The lexer treats a string containing a structural character exactly
    like the structural character.

(7) Tokens trailing the first expression in a section are silently
    ignored.

(8) The parser accepts any token in place of a colon.

(9) The parser treats comma as optional.

(10) parse() crashes on unexpected EOF.

(11) parse_schema() crashes when a section's expression isn't a JSON
    object.

Replace this piece of original art by a thoroughly unoriginal design.
Takes care of (1), (2), (5), (6) and (7), and lays the groundwork for
addressing the others.  Generated source files remain unchanged.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1374939721-7876-4-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-29 10:37:10 -05:00

318 lines
8.4 KiB
Python

#
# QAPI helper library
#
# Copyright IBM, Corp. 2011
# Copyright (c) 2013 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 GPLv2.
# See the COPYING.LIB file in the top-level directory.
from ordereddict import OrderedDict
builtin_types = [
'str', 'int', 'number', 'bool',
'int8', 'int16', 'int32', 'int64',
'uint8', 'uint16', 'uint32', 'uint64'
]
builtin_type_qtypes = {
'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',
}
class QAPISchema:
def __init__(self, fp):
self.fp = fp
self.src = fp.read()
if self.src == '' or self.src[-1] != '\n':
self.src += '\n'
self.cursor = 0
self.exprs = []
self.accept()
while self.tok != None:
self.exprs.append(self.get_expr())
def accept(self):
while True:
bol = self.cursor == 0 or self.src[self.cursor-1] == '\n'
self.tok = self.src[self.cursor]
self.cursor += 1
self.val = None
if self.tok == '#' and bol:
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 Exception("Mismatched quotes")
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
def get_members(self):
expr = OrderedDict()
while self.tok != '}':
key = self.val
self.accept()
self.accept() # :
expr[key] = self.get_expr()
if self.tok == ',':
self.accept()
self.accept()
return expr
def get_values(self):
expr = []
while self.tok != ']':
expr.append(self.get_expr())
if self.tok == ',':
self.accept()
self.accept()
return expr
def get_expr(self):
if self.tok == '{':
self.accept()
expr = self.get_members()
elif self.tok == '[':
self.accept()
expr = self.get_values()
else:
expr = self.val
self.accept()
return expr
def parse_schema(fp):
schema = QAPISchema(fp)
exprs = []
for expr_eval in schema.exprs:
if expr_eval.has_key('enum'):
add_enum(expr_eval['enum'])
elif expr_eval.has_key('union'):
add_union(expr_eval)
add_enum('%sKind' % expr_eval['union'])
elif expr_eval.has_key('type'):
add_struct(expr_eval)
exprs.append(expr_eval)
return exprs
def parse_args(typeinfo):
if isinstance(typeinfo, basestring):
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'])
# namespace pollution:
polluted_words = set(['unix'])
if protect and (name in c89_words | c99_words | c11_words | gcc_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):
global enum_types
enum_types.append(name)
def is_enum(name):
global enum_types
return (name in enum_types)
def c_type(name):
if name == 'str':
return 'char *'
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 *' % c_list_type(name[0])
elif is_enum(name):
return name
elif name == None or len(name) == 0:
return 'void'
elif name == name.upper():
return '%sEvent *' % camel_case(name)
else:
return '%s *' % name
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):
return cgen('\n'.join(code.split('\n')[1:-1]), **kwds)
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))