xref: /qemu/scripts/qapi/main.py (revision 94d689d0c6f23dc3129e8432c496ccb866788dbf) 
1# This work is licensed under the terms of the GNU GPL, version 2 or later.
2# See the COPYING file in the top-level directory.
3
4"""
5QAPI Generator
6
7This is the main entry point for generating C code from the QAPI schema.
8"""
9
10import argparse
11from importlib import import_module
12import sys
13from typing import Optional
14
15from .backend import QAPIBackend, QAPICBackend
16from .common import must_match
17from .error import QAPIError
18from .schema import QAPISchema
19
20
21def invalid_prefix_char(prefix: str) -> Optional[str]:
22    match = must_match(r'([A-Za-z_.-][A-Za-z0-9_.-]*)?', prefix)
23    if match.end() != len(prefix):
24        return prefix[match.end()]
25    return None
26
27
28def create_backend(path: str) -> QAPIBackend:
29    if path is None:
30        return QAPICBackend()
31
32    module_path, dot, class_name = path.rpartition('.')
33    if not dot:
34        raise QAPIError("argument of -B must be of the form MODULE.CLASS")
35
36    try:
37        mod = import_module(module_path)
38    except Exception as ex:
39        raise QAPIError(f"unable to import '{module_path}': {ex}") from ex
40
41    try:
42        klass = getattr(mod, class_name)
43    except AttributeError as ex:
44        raise QAPIError(
45            f"module '{module_path}' has no class '{class_name}'") from ex
46
47    try:
48        backend = klass()
49    except Exception as ex:
50        raise QAPIError(
51            f"backend '{path}' cannot be instantiated: {ex}") from ex
52
53    if not isinstance(backend, QAPIBackend):
54        raise QAPIError(
55            f"backend '{path}' must be an instance of QAPIBackend")
56
57    return backend
58
59
60def main() -> int:
61    """
62    gapi-gen executable entry point.
63    Expects arguments via sys.argv, see --help for details.
64
65    :return: int, 0 on success, 1 on failure.
66    """
67    parser = argparse.ArgumentParser(
68        description='Generate code from a QAPI schema')
69    parser.add_argument('-b', '--builtins', action='store_true',
70                        help="generate code for built-in types")
71    parser.add_argument('-o', '--output-dir', action='store',
72                        default='',
73                        help="write output to directory OUTPUT_DIR")
74    parser.add_argument('-p', '--prefix', action='store',
75                        default='',
76                        help="prefix for symbols")
77    parser.add_argument('-u', '--unmask-non-abi-names', action='store_true',
78                        dest='unmask',
79                        help="expose non-ABI names in introspection")
80    parser.add_argument('-B', '--backend', default=None,
81                        help="Python module name for code generator")
82
83    # Option --suppress-tracing exists so we can avoid solving build system
84    # problems.  TODO Drop it when we no longer need it.
85    parser.add_argument('--suppress-tracing', action='store_true',
86                        help="suppress adding trace events to qmp marshals")
87
88    parser.add_argument('schema', action='store')
89    args = parser.parse_args()
90
91    funny_char = invalid_prefix_char(args.prefix)
92    if funny_char:
93        msg = f"funny character '{funny_char}' in argument of --prefix"
94        print(f"{sys.argv[0]}: {msg}", file=sys.stderr)
95        return 1
96
97    try:
98        schema = QAPISchema(args.schema)
99        backend = create_backend(args.backend)
100        backend.generate(schema,
101                         output_dir=args.output_dir,
102                         prefix=args.prefix,
103                         unmask=args.unmask,
104                         builtins=args.builtins,
105                         gen_tracing=not args.suppress_tracing)
106    except QAPIError as err:
107        print(err, file=sys.stderr)
108        return 1
109    return 0
110