xref: /qemu/scripts/qapi/common.py (revision 727385c4) 
1#
2# QAPI helper library
3#
4# Copyright IBM, Corp. 2011
5# Copyright (c) 2013-2018 Red Hat Inc.
6#
7# Authors:
8#  Anthony Liguori <aliguori@us.ibm.com>
9#  Markus Armbruster <armbru@redhat.com>
10#
11# This work is licensed under the terms of the GNU GPL, version 2.
12# See the COPYING file in the top-level directory.
13
14import re
15from typing import (
16    Any,
17    Dict,
18    Match,
19    Optional,
20    Sequence,
21    Union,
22)
23
24
25#: Magic string that gets removed along with all space to its right.
26EATSPACE = '\033EATSPACE.'
27POINTER_SUFFIX = ' *' + EATSPACE
28
29
30def camel_to_upper(value: str) -> str:
31    """
32    Converts CamelCase to CAMEL_CASE.
33
34    Examples::
35
36        ENUMName -> ENUM_NAME
37        EnumName1 -> ENUM_NAME1
38        ENUM_NAME -> ENUM_NAME
39        ENUM_NAME1 -> ENUM_NAME1
40        ENUM_Name2 -> ENUM_NAME2
41        ENUM24_Name -> ENUM24_NAME
42    """
43    c_fun_str = c_name(value, False)
44    if value.isupper():
45        return c_fun_str
46
47    new_name = ''
48    length = len(c_fun_str)
49    for i in range(length):
50        char = c_fun_str[i]
51        # When char is upper case and no '_' appears before, do more checks
52        if char.isupper() and (i > 0) and c_fun_str[i - 1] != '_':
53            if i < length - 1 and c_fun_str[i + 1].islower():
54                new_name += '_'
55            elif c_fun_str[i - 1].isdigit():
56                new_name += '_'
57        new_name += char
58    return new_name.lstrip('_').upper()
59
60
61def c_enum_const(type_name: str,
62                 const_name: str,
63                 prefix: Optional[str] = None) -> str:
64    """
65    Generate a C enumeration constant name.
66
67    :param type_name: The name of the enumeration.
68    :param const_name: The name of this constant.
69    :param prefix: Optional, prefix that overrides the type_name.
70    """
71    if prefix is not None:
72        type_name = prefix
73    return camel_to_upper(type_name) + '_' + c_name(const_name, False).upper()
74
75
76def c_name(name: str, protect: bool = True) -> str:
77    """
78    Map ``name`` to a valid C identifier.
79
80    Used for converting 'name' from a 'name':'type' qapi definition
81    into a generated struct member, as well as converting type names
82    into substrings of a generated C function name.
83
84    '__a.b_c' -> '__a_b_c', 'x-foo' -> 'x_foo'
85    protect=True: 'int' -> 'q_int'; protect=False: 'int' -> 'int'
86
87    :param name: The name to map.
88    :param protect: If true, avoid returning certain ticklish identifiers
89                    (like C keywords) by prepending ``q_``.
90    """
91    # ANSI X3J11/88-090, 3.1.1
92    c89_words = set(['auto', 'break', 'case', 'char', 'const', 'continue',
93                     'default', 'do', 'double', 'else', 'enum', 'extern',
94                     'float', 'for', 'goto', 'if', 'int', 'long', 'register',
95                     'return', 'short', 'signed', 'sizeof', 'static',
96                     'struct', 'switch', 'typedef', 'union', 'unsigned',
97                     'void', 'volatile', 'while'])
98    # ISO/IEC 9899:1999, 6.4.1
99    c99_words = set(['inline', 'restrict', '_Bool', '_Complex', '_Imaginary'])
100    # ISO/IEC 9899:2011, 6.4.1
101    c11_words = set(['_Alignas', '_Alignof', '_Atomic', '_Generic',
102                     '_Noreturn', '_Static_assert', '_Thread_local'])
103    # GCC http://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/C-Extensions.html
104    # excluding _.*
105    gcc_words = set(['asm', 'typeof'])
106    # C++ ISO/IEC 14882:2003 2.11
107    cpp_words = set(['bool', 'catch', 'class', 'const_cast', 'delete',
108                     'dynamic_cast', 'explicit', 'false', 'friend', 'mutable',
109                     'namespace', 'new', 'operator', 'private', 'protected',
110                     'public', 'reinterpret_cast', 'static_cast', 'template',
111                     'this', 'throw', 'true', 'try', 'typeid', 'typename',
112                     'using', 'virtual', 'wchar_t',
113                     # alternative representations
114                     'and', 'and_eq', 'bitand', 'bitor', 'compl', 'not',
115                     'not_eq', 'or', 'or_eq', 'xor', 'xor_eq'])
116    # namespace pollution:
117    polluted_words = set(['unix', 'errno', 'mips', 'sparc', 'i386'])
118    name = re.sub(r'[^A-Za-z0-9_]', '_', name)
119    if protect and (name in (c89_words | c99_words | c11_words | gcc_words
120                             | cpp_words | polluted_words)
121                    or name[0].isdigit()):
122        return 'q_' + name
123    return name
124
125
126class Indentation:
127    """
128    Indentation level management.
129
130    :param initial: Initial number of spaces, default 0.
131    """
132    def __init__(self, initial: int = 0) -> None:
133        self._level = initial
134
135    def __repr__(self) -> str:
136        return "{}({:d})".format(type(self).__name__, self._level)
137
138    def __str__(self) -> str:
139        """Return the current indentation as a string of spaces."""
140        return ' ' * self._level
141
142    def increase(self, amount: int = 4) -> None:
143        """Increase the indentation level by ``amount``, default 4."""
144        self._level += amount
145
146    def decrease(self, amount: int = 4) -> None:
147        """Decrease the indentation level by ``amount``, default 4."""
148        assert amount <= self._level
149        self._level -= amount
150
151
152#: Global, current indent level for code generation.
153indent = Indentation()
154
155
156def cgen(code: str, **kwds: object) -> str:
157    """
158    Generate ``code`` with ``kwds`` interpolated.
159
160    Obey `indent`, and strip `EATSPACE`.
161    """
162    raw = code % kwds
163    pfx = str(indent)
164    if pfx:
165        raw = re.sub(r'^(?!(#|$))', pfx, raw, flags=re.MULTILINE)
166    return re.sub(re.escape(EATSPACE) + r' *', '', raw)
167
168
169def mcgen(code: str, **kwds: object) -> str:
170    if code[0] == '\n':
171        code = code[1:]
172    return cgen(code, **kwds)
173
174
175def c_fname(filename: str) -> str:
176    return re.sub(r'[^A-Za-z0-9_]', '_', filename)
177
178
179def guardstart(name: str) -> str:
180    return mcgen('''
181#ifndef %(name)s
182#define %(name)s
183
184''',
185                 name=c_fname(name).upper())
186
187
188def guardend(name: str) -> str:
189    return mcgen('''
190
191#endif /* %(name)s */
192''',
193                 name=c_fname(name).upper())
194
195
196def gen_ifcond(ifcond: Optional[Union[str, Dict[str, Any]]],
197               cond_fmt: str, not_fmt: str,
198               all_operator: str, any_operator: str) -> str:
199
200    def do_gen(ifcond: Union[str, Dict[str, Any]],
201               need_parens: bool) -> str:
202        if isinstance(ifcond, str):
203            return cond_fmt % ifcond
204        assert isinstance(ifcond, dict) and len(ifcond) == 1
205        if 'not' in ifcond:
206            return not_fmt % do_gen(ifcond['not'], True)
207        if 'all' in ifcond:
208            gen = gen_infix(all_operator, ifcond['all'])
209        else:
210            gen = gen_infix(any_operator, ifcond['any'])
211        if need_parens:
212            gen = '(' + gen + ')'
213        return gen
214
215    def gen_infix(operator: str, operands: Sequence[Any]) -> str:
216        return operator.join([do_gen(o, True) for o in operands])
217
218    if not ifcond:
219        return ''
220    return do_gen(ifcond, False)
221
222
223def cgen_ifcond(ifcond: Optional[Union[str, Dict[str, Any]]]) -> str:
224    return gen_ifcond(ifcond, 'defined(%s)', '!%s', ' && ', ' || ')
225
226
227def docgen_ifcond(ifcond: Optional[Union[str, Dict[str, Any]]]) -> str:
228    # TODO Doc generated for conditions needs polish
229    return gen_ifcond(ifcond, '%s', 'not %s', ' and ', ' or ')
230
231
232def gen_if(cond: str) -> str:
233    if not cond:
234        return ''
235    return mcgen('''
236#if %(cond)s
237''', cond=cond)
238
239
240def gen_endif(cond: str) -> str:
241    if not cond:
242        return ''
243    return mcgen('''
244#endif /* %(cond)s */
245''', cond=cond)
246
247
248def must_match(pattern: str, string: str) -> Match[str]:
249    match = re.match(pattern, string)
250    assert match is not None
251    return match
252