mbedtls/scripts/generate_ssl_debug_helpers.py
Dave Rodgman 4914d50c73 Fix spelling error in generated helper code
Also a minor comment fix in the generator script.

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
2022-04-22 15:26:50 +01:00

382 lines
12 KiB
Python
Executable File

#!/usr/bin/env python3
"""Generate library/ssl_debug_helpers_generated.c
The code generated by this module includes debug helper functions that can not be
implemented by fixed codes.
"""
# Copyright The Mbed TLS Contributors
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import sys
import re
import os
import textwrap
import argparse
from mbedtls_dev import build_tree
def remove_c_comments(string):
"""
Remove C style comments from input string
"""
string_pattern = r"(?P<string>\".*?\"|\'.*?\')"
comment_pattern = r"(?P<comment>/\*.*?\*/|//[^\r\n]*$)"
pattern = re.compile(string_pattern + r'|' + comment_pattern,
re.MULTILINE | re.DOTALL)
def replacer(match):
if match.lastgroup == 'comment':
return ""
return match.group()
return pattern.sub(replacer, string)
class CondDirectiveNotMatch(Exception):
pass
def preprocess_c_source_code(source, *classes):
"""
Simple preprocessor for C source code.
Only processses condition directives without expanding them.
Yield object according to the classes input. Most match firstly
If the directive pair does not match , raise CondDirectiveNotMatch.
Assume source code does not include comments and compile pass.
"""
pattern = re.compile(r"^[ \t]*#[ \t]*" +
r"(?P<directive>(if[ \t]|ifndef[ \t]|ifdef[ \t]|else|endif))" +
r"[ \t]*(?P<param>(.*\\\n)*.*$)",
re.MULTILINE)
stack = []
def _yield_objects(s, d, p, st, end):
"""
Output matched source piece
"""
nonlocal stack
start_line, end_line = '', ''
if stack:
start_line = '#{} {}'.format(d, p)
if d == 'if':
end_line = '#endif /* {} */'.format(p)
elif d == 'ifdef':
end_line = '#endif /* defined({}) */'.format(p)
else:
end_line = '#endif /* !defined({}) */'.format(p)
has_instance = False
for cls in classes:
for instance in cls.extract(s, st, end):
if has_instance is False:
has_instance = True
yield pair_start, start_line
yield instance.span()[0], instance
if has_instance:
yield start, end_line
for match in pattern.finditer(source):
directive = match.groupdict()['directive'].strip()
param = match.groupdict()['param']
start, end = match.span()
if directive in ('if', 'ifndef', 'ifdef'):
stack.append((directive, param, start, end))
continue
if not stack:
raise CondDirectiveNotMatch()
pair_directive, pair_param, pair_start, pair_end = stack.pop()
yield from _yield_objects(source,
pair_directive,
pair_param,
pair_end,
start)
if directive == 'endif':
continue
if pair_directive == 'if':
directive = 'if'
param = "!( {} )".format(pair_param)
elif pair_directive == 'ifdef':
directive = 'ifndef'
param = pair_param
else:
directive = 'ifdef'
param = pair_param
stack.append((directive, param, start, end))
assert not stack, len(stack)
class EnumDefinition:
"""
Generate helper functions around enumeration.
Currently, it generate translation function from enum value to string.
Enum definition looks like:
[typedef] enum [prefix name] { [body] } [suffix name];
Known limitation:
- the '}' and ';' SHOULD NOT exist in different macro blocks. Like
```
enum test {
....
#if defined(A)
....
};
#else
....
};
#endif
```
"""
@classmethod
def extract(cls, source_code, start=0, end=-1):
enum_pattern = re.compile(r'enum\s*(?P<prefix_name>\w*)\s*' +
r'{\s*(?P<body>[^}]*)}' +
r'\s*(?P<suffix_name>\w*)\s*;',
re.MULTILINE | re.DOTALL)
for match in enum_pattern.finditer(source_code, start, end):
yield EnumDefinition(source_code,
span=match.span(),
group=match.groupdict())
def __init__(self, source_code, span=None, group=None):
assert isinstance(group, dict)
prefix_name = group.get('prefix_name', None)
suffix_name = group.get('suffix_name', None)
body = group.get('body', None)
assert prefix_name or suffix_name
assert body
assert span
# If suffix_name exists, it is a typedef
self._prototype = suffix_name if suffix_name else 'enum ' + prefix_name
self._name = suffix_name if suffix_name else prefix_name
self._body = body
self._source = source_code
self._span = span
def __repr__(self):
return 'Enum({},{})'.format(self._name, self._span)
def __str__(self):
return repr(self)
def span(self):
return self._span
def generate_translation_function(self):
"""
Generate function for translating value to string
"""
translation_table = []
for line in self._body.splitlines():
if line.strip().startswith('#'):
# Preprocess directive, keep it in table
translation_table.append(line.strip())
continue
if not line.strip():
continue
for field in line.strip().split(','):
if not field.strip():
continue
member = field.strip().split()[0]
translation_table.append(
'{space}[{member}] = "{member}",'.format(member=member,
space=' '*8)
)
body = textwrap.dedent('''\
const char *{name}_str( {prototype} in )
{{
const char * in_to_str[]=
{{
{translation_table}
}};
if( in > ( sizeof( in_to_str )/sizeof( in_to_str[0]) - 1 ) ||
in_to_str[ in ] == NULL )
{{
return "UNKNOWN_VALUE";
}}
return in_to_str[ in ];
}}
''')
body = body.format(translation_table='\n'.join(translation_table),
name=self._name,
prototype=self._prototype)
return body
class SignatureAlgorithmDefinition:
"""
Generate helper functions for signature algorithms.
It generates translation function from signature algorithm define to string.
Signature algorithm definition looks like:
#define MBEDTLS_TLS1_3_SIG_[ upper case signature algorithm ] [ value(hex) ]
Known limitation:
- the definitions SHOULD exist in same macro blocks.
"""
@classmethod
def extract(cls, source_code, start=0, end=-1):
sig_alg_pattern = re.compile(r'#define\s+(?P<name>MBEDTLS_TLS1_3_SIG_\w+)\s+' +
r'(?P<value>0[xX][0-9a-fA-F]+)$',
re.MULTILINE | re.DOTALL)
matches = list(sig_alg_pattern.finditer(source_code, start, end))
if matches:
yield SignatureAlgorithmDefinition(source_code, definitions=matches)
def __init__(self, source_code, definitions=None):
if definitions is None:
definitions = []
assert isinstance(definitions, list) and definitions
self._definitions = definitions
self._source = source_code
def __repr__(self):
return 'SigAlgs({})'.format(self._definitions[0].span())
def span(self):
return self._definitions[0].span()
def __str__(self):
"""
Generate function for translating value to string
"""
translation_table = []
for m in self._definitions:
name = m.groupdict()['name']
translation_table.append(
'\tcase {}:\n\t return "{}";'.format(name,
name[len('MBEDTLS_TLS1_3_SIG_'):].lower())
)
body = textwrap.dedent('''\
const char *mbedtls_ssl_sig_alg_to_str( uint16_t in )
{{
switch( in )
{{
{translation_table}
}};
return "UNKOWN";
}}''')
body = body.format(translation_table='\n'.join(translation_table))
return body
OUTPUT_C_TEMPLATE = '''\
/* Automatically generated by generate_ssl_debug_helpers.py. DO NOT EDIT. */
/**
* \\file ssl_debug_helpers_generated.c
*
* \\brief Automatically generated helper functions for debugging
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_DEBUG_C)
#include "ssl_debug_helpers.h"
{functions}
#endif /* MBEDTLS_DEBUG_C */
/* End of automatically generated file. */
'''
def generate_ssl_debug_helpers(output_directory, mbedtls_root):
"""
Generate functions of debug helps
"""
mbedtls_root = os.path.abspath(mbedtls_root or build_tree.guess_mbedtls_root())
with open(os.path.join(mbedtls_root, 'include/mbedtls/ssl.h')) as f:
source_code = remove_c_comments(f.read())
definitions = dict()
for start, instance in preprocess_c_source_code(source_code,
EnumDefinition,
SignatureAlgorithmDefinition):
if start in definitions:
continue
if isinstance(instance, EnumDefinition):
definition = instance.generate_translation_function()
else:
definition = instance
definitions[start] = definition
function_definitions = [str(v) for _, v in sorted(definitions.items())]
if output_directory == sys.stdout:
sys.stdout.write(OUTPUT_C_TEMPLATE.format(
functions='\n'.join(function_definitions)))
else:
with open(os.path.join(output_directory, 'ssl_debug_helpers_generated.c'), 'w') as f:
f.write(OUTPUT_C_TEMPLATE.format(
functions='\n'.join(function_definitions)))
def main():
"""
Command line entry
"""
parser = argparse.ArgumentParser()
parser.add_argument('--mbedtls-root', nargs='?', default=None,
help='root directory of mbedtls source code')
parser.add_argument('output_directory', nargs='?',
default='library', help='source/header files location')
args = parser.parse_args()
generate_ssl_debug_helpers(args.output_directory, args.mbedtls_root)
return 0
if __name__ == '__main__':
sys.exit(main())