blob: 4079cc02d6fd7a1b7db802ac6f40d5310eb0e687 [file] [log] [blame]
# pycrc -- parameterisable CRC calculation utility and C source code generator
#
# Copyright (c) 2017 Thomas Pircher <tehpeh-web@tty1.net>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
"""
use as follows:
import pycrc.codegen as cg
import pycrc.opt as opt
opt = opt.Options()
print(cg.CodeGen(opt, '', [
'if (a == b) {',
cg.CodeGen(opt, 4*' ', ['print("a equals b\\n");']),
'}',
]))
"""
import pycrc.symtable
import pycrc.expr as expr
class CodeGen(object):
"""
The symbol table class.
"""
def __init__(self, opt, indent, content = []):
"""
The class constructor.
"""
self.opt = opt
self.sym = pycrc.symtable.SymbolTable(opt)
self.indent = indent
self.content = content
def gen(self, indent = ''):
"""
Return an array of strings.
"""
out = []
if self.indent is None:
indent = ''
else:
indent += self.indent
for item in self.content:
if isinstance(item, str):
out.append(indent + item)
else:
out += item.gen(indent)
return out
def __str__(self):
"""
Stringify the object.
"""
return '\n'.join([l.rstrip() for l in self.gen()])
class Conditional(CodeGen):
"""
A conditional block of code.
"""
def __init__(self, opt, indent, condition, content):
"""
The class constructor.
"""
super(Conditional, self).__init__(opt, indent)
if condition:
self.content = content
class Conditional2(CodeGen):
"""
A conditional block of code with an else block.
"""
def __init__(self, opt, indent, condition, content_true, content_false):
"""
The class constructor.
"""
super(Conditional2, self).__init__(opt, indent)
if condition:
self.content = content_true
else:
self.content = content_false
class Comment(CodeGen):
"""
A comment wrapper.
"""
def __init__(self, opt, indent, content):
"""
The class constructor.
"""
super(Comment, self).__init__(opt, indent)
self.content = [
'/**',
CodeGen(opt, indent + ' * ', content),
' */'
]
class ParamBlock(CodeGen):
"""
Print the parameters of the model.
"""
def __init__(self, opt, indent, algorithm = False):
"""
The class constructor.
"""
super(ParamBlock, self).__init__(opt, indent)
self.content = [
'- {0:13s} = {1}'.format('Width', self.sym['crc_width']),
'- {0:13s} = {1}'.format('Poly', self.sym['crc_poly']),
'- {0:13s} = {1}'.format('XorIn', self.sym['crc_xor_in']),
'- {0:13s} = {1}'.format('ReflectIn', self.sym['crc_reflect_in']),
'- {0:13s} = {1}'.format('XorOut', self.sym['crc_xor_out']),
'- {0:13s} = {1}'.format('ReflectOut', self.sym['crc_reflect_out']),
Conditional(opt, '', algorithm,
['- {0:13s} = {1}'.format('Algorithm', self.sym['crc_algorithm'])]),
Conditional(opt, '', opt.slice_by > 1,
['- {0:13s} = {1}'.format('SliceBy', opt.slice_by)]),
]
class File(CodeGen):
"""
Generate the file output.
"""
def __init__(self, opt, indent):
"""
The class constructor.
"""
super(File, self).__init__(opt, indent)
self.content = [
Comment(opt, '', [
'\\file',
'Functions and types for CRC checks.',
'',
'Generated on {datetime}'.format(**self.sym),
'by {program_version}, {program_url}'.format(**self.sym),
'using the configuration:',
ParamBlock(opt, ' ', algorithm = True),
Conditional(opt, '', opt.action == opt.action_generate_h, [
'',
'This file defines the functions {crc_init_function}(), ' \
'{crc_update_function}() and {crc_finalize_function}().'.format(**self.sym),
'',
'The {crc_init_function}() function returns the inital \c crc value and must be called'.format(**self.sym),
'before the first call to {crc_update_function}().'.format(**self.sym),
'Similarly, the {crc_finalize_function}() function must be called after the last call'.format(**self.sym),
'to {crc_update_function}(), before the \c crc is being used.'.format(**self.sym),
'is being used.',
'',
'The {crc_update_function}() function can be called any number of times (including zero'.format(**self.sym),
'times) in between the {crc_init_function}() and {crc_finalize_function}() calls.'.format(**self.sym),
'',
'This pseudo-code shows an example usage of the API:',
'\code{.c}',
Conditional(self.opt, '', self.opt.undefined_crc_parameters, [
'{cfg_t} cfg = '.format(**self.sym) + '{',
Conditional(self.opt, 4*' ', self.opt.width is None, [
'0, // width',
]),
Conditional(self.opt, 4*' ', self.opt.poly is None, [
'0, // poly',
]),
Conditional(self.opt, 4*' ', self.opt.reflect_in is None, [
'0, // reflect_in',
]),
Conditional(self.opt, 4*' ', self.opt.xor_in is None, [
'0, // xor_in',
]),
Conditional(self.opt, 4*' ', self.opt.reflect_out is None, [
'0, // reflect_out',
]),
Conditional(self.opt, 4*' ', self.opt.xor_out is None, [
'0, // xor_out',
]),
Conditional(self.opt, 4*' ', self.opt.width is None, [
'',
'0, // crc_mask',
'0, // msb_mask',
'0, // crc_shift',
]),
'};',
]),
'{crc_t} crc;'.format(**self.sym),
'unsigned char data[MAX_DATA_LEN];',
'size_t data_len;',
'',
Conditional(self.opt, '', _use_crc_table_gen(self.opt), [
'{crc_table_gen_function}(&cfg);'.format(**self.sym),
]),
'crc = {0}({1});'.format(self.sym['crc_init_function'], '' if _use_constant_crc_init(self.sym) else '&cfg'),
'while ((data_len = read_data(data, MAX_DATA_LEN)) > 0) {',
CodeGen(self.opt, 4*' ', [
'crc = {0}({1}crc, data, data_len);'.format(self.sym['crc_update_function'], '' if _use_cfg_in_crc_update(self.opt) else '&cfg, '),
]),
'}',
'crc = {0}({1}crc);'.format(self.sym['crc_finalize_function'], '' if _use_cfg_in_finalize(self.opt) else '&cfg, '),
'\endcode',
]),
]),
]
if opt.action == opt.action_generate_h:
self.content += self._header_file()
elif opt.action == opt.action_generate_c:
self.content += self._c_file()
elif opt.action == opt.action_generate_c_main:
self.content += self._c_file() + self._main_file()
def _header_file(self):
"""
Add header content.
"""
out = [
'#ifndef {header_protection}'.format(**self.sym),
'#define {header_protection}'.format(**self.sym),
'',
CodeGen(self.opt, '', _includes(self.opt)),
'#include <stdlib.h>',
Conditional(self.opt, '', self.opt.c_std != 'C89',
['#include <stdint.h>']),
Conditional(self.opt, '', _use_cfg(self.opt) and self.opt.c_std != 'C89',
['#include <stdbool.h>']),
'',
'#ifdef __cplusplus',
'extern "C" {',
'#endif',
'', '',
Comment(self.opt, '', [
'The definition of the used algorithm.',
'',
'This is not used anywhere in the generated code, but it may be used by the',
'application code to call algorithm-specific code, if desired.',
]),
'#define {0} 1'.format(_crc_algo_define(self.opt, self.sym)),
'', '',
Comment(self.opt, self.indent, [
'The type of the CRC values.',
'',
'This type must be big enough to contain at least {cfg_width} bits.'.format(**self.sym),
]),
'typedef {underlying_crc_t} {crc_t};'.format(**self.sym),
Conditional(self.opt, '', _use_cfg(self.opt), [
'', '',
Comment(self.opt, self.indent, ['The configuration type of the CRC algorithm.']),
'typedef struct {',
Conditional(self.opt, 4*' ', self.opt.width is None,
['{0:24s} {1}'.format('unsigned int width;',
'/*!< The width of the polynomial */')]),
Conditional(self.opt, 4*' ', self.opt.poly is None,
['{0:24s} {1}'.format(self.sym['crc_t'] + ' poly;',
'/*!< The CRC polynomial */')]),
Conditional(self.opt, 4*' ', self.opt.reflect_in is None,
['{0:24s} {1}'.format(self.sym['c_bool'] + ' reflect_in;',
'/*!< Whether the input shall be reflected or not */')]),
Conditional(self.opt, 4*' ', self.opt.xor_in is None,
['{0:24s} {1}'.format(self.sym['crc_t'] + ' xor_in;',
'/*!< The initial value of the register */')]),
Conditional(self.opt, 4*' ', self.opt.reflect_out is None,
['{0:24s} {1}'.format(self.sym['c_bool'] + ' reflect_out;',
'/*!< Whether the output shall be reflected or not */')]),
Conditional(self.opt, 4*' ', self.opt.xor_out is None,
['{0:24s} {1}'.format(self.sym['crc_t'] + ' xor_out;',
'/*!< The value which shall be XOR-ed to the final CRC value */')]),
Conditional(self.opt, 4*' ', self.opt.width is None, [
'',
'/* internal parameters */',
'{0:24s} {1}'.format(self.sym['crc_t'] + ' msb_mask;', '/*!< a bitmask with the Most Significant Bit set to 1'),
33*' ' + 'initialise as (crc_t)1u << (width - 1) */',
'{0:24s} {1}'.format(self.sym['crc_t'] + ' crc_mask;', '/*!< a bitmask with all width bits set to 1'),
33*' ' + 'initialise as (cfg->msb_mask - 1) | cfg->msb_mask */',
'{0:24s} {1}'.format('unsigned int crc_shift;', '/*!< a shift count that is used when width < 8'),
33*' ' + 'initialise as cfg->width < 8 ? 8 - cfg->width : 0 */',
]),
'}} {cfg_t};'.format(**self.sym),
]),
Conditional(self.opt, '', _use_reflect_func(self.opt) and not _use_static_reflect_func(self.opt), [
'', '',
Comment(self.opt, '', [
'Reflect all bits of a \\a data word of \\a data_len bytes.',
'',
'\\param[in] data The data word to be reflected.',
'\\param[in] data_len The width of \\a data expressed in number of bits.',
'\\return The reflected data.'
]),
'{crc_t} {crc_reflect_function}({crc_t} data, size_t data_len);'.format(**self.sym),
]),
Conditional(self.opt, '', _use_crc_table_gen(self.opt), [
'', '',
Comment(self.opt, '', [
'Populate the private static crc table.',
'',
'\\param[in] cfg A pointer to an initialised {cfg_t} structure.'.format(**self.sym),
]),
'void {crc_table_gen_function}(const {cfg_t} *cfg);'.format(**self.sym),
]),
'', '',
Comment(self.opt, '', [
'Calculate the initial crc value.',
'',
Conditional(self.opt, '', _use_cfg(self.opt), [
'\\param[in] cfg A pointer to an initialised {cfg_t} structure.'.format(**self.sym),
]),
'\\return The initial crc value.',
]),
Conditional2(self.opt, '', _use_constant_crc_init(self.sym), [
Conditional2(self.opt, '', self.opt.c_std == 'C89', [
'#define {crc_init_function}() ({crc_init_value})'.format(**self.sym),
], [
'static inline {0}'.format(_crc_init_function_def(self.opt, self.sym)),
'{',
' return {crc_init_value};'.format(**self.sym),
'}',
]),
], [
'{0};'.format(_crc_init_function_def(self.opt, self.sym)),
]),
'', '',
Comment(self.opt, '', [
'Update the crc value with new data.',
'',
'\\param[in] crc The current crc value.',
Conditional(self.opt, '', not _use_cfg_in_crc_update(self.opt), [
'\\param[in] cfg A pointer to an initialised {cfg_t} structure.'.format(**self.sym),
]),
'\\param[in] data Pointer to a buffer of \\a data_len bytes.',
'\\param[in] data_len Number of bytes in the \\a data buffer.',
'\\return The updated crc value.',
]),
'{0};'.format(_crc_update_function_def(self.opt, self.sym)),
'', '',
Comment(self.opt, '', [
'Calculate the final crc value.',
'',
Conditional(self.opt, '', not _use_cfg_in_finalize(self.opt), [
'\\param[in] cfg A pointer to an initialised {cfg_t} structure.'.format(**self.sym),
]),
'\\param[in] crc The current crc value.',
'\\return The final crc value.',
]),
Conditional2(self.opt, '', _use_inline_crc_finalize(self.opt), [
Conditional2(self.opt, '', self.opt.c_std == 'C89', [
'#define {0}(crc) ({1})'.format(self.sym['crc_finalize_function'], _crc_final_value(self.opt, self.sym)),
], [
'static inline {0}'.format(_crc_finalize_function_def(self.opt, self.sym)),
'{',
' return {0};'.format(_crc_final_value(self.opt, self.sym)),
'}',
]),
], [
'{0};'.format(_crc_finalize_function_def(self.opt, self.sym)),
]),
'', '',
'#ifdef __cplusplus',
'} /* closing brace for extern "C" */',
'#endif',
'',
'#endif /* {header_protection} */'.format(**self.sym),
'',
]
return out
def _c_file(self):
"""
Add C file content.
"""
out = [
CodeGen(self.opt, '', _includes(self.opt)),
'#include "{header_filename}" /* include the header file generated with pycrc */'.format(**self.sym),
'#include <stdlib.h>',
Conditional(self.opt, '', self.opt.c_std != 'C89', [
'#include <stdint.h>',
Conditional(self.opt, '', self.opt.undefined_crc_parameters or \
self.opt.algorithm == self.opt.algo_bit_by_bit or \
self.opt.algorithm == self.opt.algo_bit_by_bit_fast, [
'#include <stdbool.h>',
]),
]),
Conditional(self.opt, '', self.opt.slice_by > 1, [
'#include <endian.h>',
]),
Conditional(self.opt, '', _use_reflect_func(self.opt) and _use_static_reflect_func(self.opt), [
'',
'static {crc_t} {crc_reflect_function}({crc_t} data, size_t data_len);'.format(**self.sym),
]),
'',
CodeGen(self.opt, '', _crc_table(self.opt, self.sym)),
CodeGen(self.opt, '', _crc_reflect_function_gen(self.opt, self.sym)),
CodeGen(self.opt, '', _crc_init_function_gen(self.opt, self.sym)),
CodeGen(self.opt, '', _crc_table_gen(self.opt, self.sym)),
CodeGen(self.opt, '', _crc_update_function_gen(self.opt, self.sym)),
CodeGen(self.opt, '', _crc_finalize_function_gen(self.opt, self.sym)),
'',
]
return out
def _main_file(self):
"""
Add main file content.
"""
out = [
'',
'',
CodeGen(self.opt, '', _includes(self.opt)),
'#include <stdio.h>',
'#include <getopt.h>',
Conditional(self.opt, '', self.opt.undefined_crc_parameters, [
'#include <stdlib.h>',
'#include <stdio.h>',
'#include <ctype.h>',
]),
Conditional(self.opt, '', self.opt.c_std != 'C89', [
'#include <stdbool.h>',
]),
'#include <string.h>',
'',
'static char str[256] = "123456789";',
'static {c_bool} verbose = {c_false};'.format(**self.sym),
self._getopt_template(),
'',
'',
Conditional2(self.opt, '', self.opt.undefined_crc_parameters, [
'static void print_params(const {cfg_t} *cfg)'.format(**self.sym),
], [
'static void print_params(void)',
]),
'{',
CodeGen(self.opt, 4*' ', [
'char format[20];',
'',
Conditional2(self.opt, '', self.opt.c_std == 'C89', [
'sprintf(format, "%%-16s = 0x%%0%dlx\\n", (unsigned int)({cfg_width} + 3) / 4);'.format(**self.sym),
'printf("%-16s = %d\\n", "width", (unsigned int){cfg_width});'.format(**self.sym),
'printf(format, "poly", (unsigned long int){cfg_poly});'.format(**self.sym),
'printf("%-16s = %s\\n", "reflect_in", {0});'.format(self.sym['cfg_reflect_in'] + ' ? "true": "false"' if self.opt.reflect_in is None else ('"true"' if self.opt.reflect_in else '"false"')),
'printf(format, "xor_in", (unsigned long int){cfg_xor_in});'.format(**self.sym),
'printf("%-16s = %s\\n", "reflect_out", {0});'.format(self.sym['cfg_reflect_out'] + ' ? "true": "false"' if self.opt.reflect_out is None else ('"true"' if self.opt.reflect_out else '"false"')),
'printf(format, "xor_out", (unsigned long int){cfg_xor_out});'.format(**self.sym),
'printf(format, "crc_mask", (unsigned long int){cfg_mask});'.format(**self.sym),
'printf(format, "msb_mask", (unsigned long int){cfg_msb_mask});'.format(**self.sym),
], [
'snprintf(format, sizeof(format), "%%-16s = 0x%%0%dllx\\n", (unsigned int)({cfg_width} + 3) / 4);'.format(**self.sym),
'printf("%-16s = %d\\n", "width", (unsigned int){cfg_width});'.format(**self.sym),
'printf(format, "poly", (unsigned long long int){cfg_poly});'.format(**self.sym),
'printf("%-16s = %s\\n", "reflect_in", {0});'.format(self.sym['cfg_reflect_in'] + ' ? "true": "false"' if self.opt.reflect_in is None else ('"true"' if self.opt.reflect_in else '"false"')),
'printf(format, "xor_in", (unsigned long long int){cfg_xor_in});'.format(**self.sym),
'printf("%-16s = %s\\n", "reflect_out", {0});'.format(self.sym['cfg_reflect_out'] + ' ? "true": "false"' if self.opt.reflect_out is None else ('"true"' if self.opt.reflect_out else '"false"')),
'printf(format, "xor_out", (unsigned long long int){cfg_xor_out});'.format(**self.sym),
'printf(format, "crc_mask", (unsigned long long int){cfg_mask});'.format(**self.sym),
'printf(format, "msb_mask", (unsigned long long int){cfg_msb_mask});'.format(**self.sym),
]),
]),
'}',
'',
'',
Comment(self.opt, '', [
'C main function.',
'\\param[in] argc the number of arguments in \\a argv.',
'\\param[in] argv a NULL-terminated array of pointers to the argument strings.',
'\\retval 0 on success.',
'\\retval >0 on error.',
]),
'int main(int argc, char *argv[])',
'{',
CodeGen(self.opt, 4*' ', [
Conditional(self.opt, '', self.opt.undefined_crc_parameters, [
'{cfg_t} cfg = '.format(**self.sym) + '{',
Conditional(self.opt, 4*' ', self.opt.width is None, [
'0, /* width */',
]),
Conditional(self.opt, 4*' ', self.opt.poly is None, [
'0, /* poly */',
]),
Conditional(self.opt, 4*' ', self.opt.reflect_in is None, [
'0, /* reflect_in */',
]),
Conditional(self.opt, 4*' ', self.opt.xor_in is None, [
'0, /* xor_in */',
]),
Conditional(self.opt, 4*' ', self.opt.reflect_out is None, [
'0, /* reflect_out */',
]),
Conditional(self.opt, 4*' ', self.opt.xor_out is None, [
'0, /* xor_out */',
]),
Conditional(self.opt, 4*' ', self.opt.width is None, [
'',
'0, /* crc_mask */',
'0, /* msb_mask */',
'0, /* crc_shift */',
]),
'};',
]),
'{crc_t} crc;'.format(**self.sym),
'',
Conditional2(self.opt, '', self.opt.undefined_crc_parameters, [
'get_config(argc, argv, &cfg);',
], [
'get_config(argc, argv);',
]),
Conditional(self.opt, '', _use_crc_table_gen(self.opt), [
'{crc_table_gen_function}(&cfg);'.format(**self.sym),
]),
'crc = {0}({1});'.format(self.sym['crc_init_function'], '' if _use_constant_crc_init(self.sym) else '&cfg'),
'crc = {0}({1}crc, (void *)str, strlen(str));'.format(self.sym['crc_update_function'], '' if _use_cfg_in_crc_update(self.opt) else '&cfg, '),
'crc = {0}({1}crc);'.format(self.sym['crc_finalize_function'], '' if _use_cfg_in_finalize(self.opt) else '&cfg, '),
'',
'if (verbose) {',
CodeGen(self.opt, 4*' ', [
'print_params({0});'.format('&cfg' if self.opt.undefined_crc_parameters else ''),
]),
'}',
Conditional2(self.opt, '', self.opt.c_std == 'C89', [
'printf("0x%lx\\n", (unsigned long int)crc);',
], [
'printf("0x%llx\\n", (unsigned long long int)crc);',
]),
'return 0;',
]),
'}',
]
return out
def _getopt_template(self):
"""
Add getopt functions.
"""
out = [
Conditional(self.opt, '', self.opt.reflect_in is None or self.opt.reflect_out is None, [
'',
'',
'static {c_bool} atob(const char *str)'.format(**self.sym),
'{',
CodeGen(self.opt, 4*' ', [
'if (!str) {',
CodeGen(self.opt, 4*' ', [
'return 0;',
]),
'}',
'if (isdigit(str[0])) {',
CodeGen(self.opt, 4*' ', [
'return ({c_bool})atoi(str);'.format(**self.sym),
]),
'}',
'if (tolower(str[0]) == \'t\') {',
CodeGen(self.opt, 4*' ', [
'return {c_true};'.format(**self.sym),
]),
'}',
'return {c_false};'.format(**self.sym),
]),
'}',
]),
Conditional(self.opt, '', self.opt.poly is None or self.opt.xor_in is None or self.opt.xor_out is None, [
'',
'',
'static crc_t xtoi(const char *str)',
'{',
CodeGen(self.opt, 4*' ', [
'crc_t ret = 0;',
'',
'if (!str) {',
CodeGen(self.opt, 4*' ', [
'return 0;',
]),
'}',
'if (str[0] == \'0\' && tolower(str[1]) == \'x\') {',
CodeGen(self.opt, 4*' ', [
'str += 2;',
'while (*str) {',
CodeGen(self.opt, 4*' ', [
'if (isdigit(*str))',
CodeGen(self.opt, 4*' ', [
'ret = 16 * ret + *str - \'0\';',
]),
'else if (isxdigit(*str))',
CodeGen(self.opt, 4*' ', [
'ret = 16 * ret + tolower(*str) - \'a\' + 10;',
]),
'else',
CodeGen(self.opt, 4*' ', [
'return ret;',
]),
'str++;',
]),
'}',
]),
'} else if (isdigit(*str)) {',
CodeGen(self.opt, 4*' ', [
'while (*str) {',
CodeGen(self.opt, 4*' ', [
'if (isdigit(*str))',
CodeGen(self.opt, 4*' ', [
'ret = 10 * ret + *str - \'0\';',
]),
'else',
CodeGen(self.opt, 4*' ', [
'return ret;',
]),
'str++;',
]),
'}',
]),
'}',
'return ret;',
]),
'}',
]),
'',
'',
Conditional2(self.opt, '', self.opt.undefined_crc_parameters, [
'static int get_config(int argc, char *argv[], {cfg_t} *cfg)'.format(**self.sym),
], [
'static int get_config(int argc, char *argv[])',
]),
'{',
CodeGen(self.opt, 4*' ', [
'int c;',
'int option_index;',
'static struct option long_options[] = {',
CodeGen(self.opt, 4*' ', [
Conditional(self.opt, '', self.opt.width is None, [
'{"width", 1, 0, \'w\'},',
]),
Conditional(self.opt, '', self.opt.poly is None, [
'{"poly", 1, 0, \'p\'},',
]),
Conditional(self.opt, '', self.opt.reflect_in is None, [
'{"reflect-in", 1, 0, \'n\'},',
]),
Conditional(self.opt, '', self.opt.xor_in is None, [
'{"xor-in", 1, 0, \'i\'},',
]),
Conditional(self.opt, '', self.opt.reflect_out is None, [
'{"reflect-out", 1, 0, \'u\'},',
]),
Conditional(self.opt, '', self.opt.xor_out is None, [
'{"xor-out", 1, 0, \'o\'},',
]),
'{"verbose", 0, 0, \'v\'},',
'{"check-string", 1, 0, \'s\'},',
Conditional(self.opt, '', self.opt.width is None, [
'{"table-idx-with", 1, 0, \'t\'},',
]),
'{0, 0, 0, 0}',
]),
'};',
'',
'while (1) {',
CodeGen(self.opt, 4*' ', [
'option_index = 0;',
'',
'c = getopt_long(argc, argv, "w:p:n:i:u:o:s:vt", long_options, &option_index);',
'if (c == -1)',
CodeGen(self.opt, 4*' ', [
'break;',
]),
'',
'switch (c) {',
CodeGen(self.opt, 4*' ', [
'case 0:',
CodeGen(self.opt, 4*' ', [
'printf("option %s", long_options[option_index].name);',
'if (optarg)',
CodeGen(self.opt, 4*' ', [
'printf(" with arg %s", optarg);',
]),
'printf("\\n");',
'break;',
]),
Conditional(self.opt, '', self.opt.width is None, [
'case \'w\':',
CodeGen(self.opt, 4*' ', [
'cfg->width = atoi(optarg);',
'break;',
]),
]),
Conditional(self.opt, '', self.opt.poly is None, [
'case \'p\':',
CodeGen(self.opt, 4*' ', [
'cfg->poly = xtoi(optarg);',
'break;',
]),
]),
Conditional(self.opt, '', self.opt.reflect_in is None, [
'case \'n\':',
CodeGen(self.opt, 4*' ', [
'cfg->reflect_in = atob(optarg);',
'break;',
]),
]),
Conditional(self.opt, '', self.opt.xor_in is None, [
'case \'i\':',
CodeGen(self.opt, 4*' ', [
'cfg->xor_in = xtoi(optarg);',
'break;',
]),
]),
Conditional(self.opt, '', self.opt.reflect_out is None, [
'case \'u\':',
CodeGen(self.opt, 4*' ', [
'cfg->reflect_out = atob(optarg);',
'break;',
]),
]),
Conditional(self.opt, '', self.opt.xor_out is None, [
'case \'o\':',
CodeGen(self.opt, 4*' ', [
'cfg->xor_out = xtoi(optarg);',
'break;',
]),
]),
'case \'s\':',
CodeGen(self.opt, 4*' ', [
'memcpy(str, optarg, strlen(optarg) < sizeof(str) ? strlen(optarg) + 1 : sizeof(str));',
'str[sizeof(str) - 1] = \'\\0\';',
'break;',
]),
'case \'v\':',
CodeGen(self.opt, 4*' ', [
'verbose = {c_true};'.format(**self.sym),
'break;',
]),
Conditional(self.opt, '', self.opt.width is None, [
'case \'t\':',
CodeGen(self.opt, 4*' ', [
'/* ignore --table_idx_width option */',
'break;',
]),
]),
'case \'?\':',
CodeGen(self.opt, 4*' ', [
'return -1;',
]),
'case \':\':',
CodeGen(self.opt, 4*' ', [
'fprintf(stderr, "missing argument to option %c\\n", c);',
'return -1;',
]),
'default:',
CodeGen(self.opt, 4*' ', [
'fprintf(stderr, "unhandled option %c\\n", c);',
'return -1;',
]),
]),
'}',
]),
'}',
Conditional(self.opt, '', self.opt.width is None, [
'cfg->msb_mask = (crc_t)1u << (cfg->width - 1);',
'cfg->crc_mask = (cfg->msb_mask - 1) | cfg->msb_mask;',
'cfg->crc_shift = cfg->width < 8 ? 8 - cfg->width : 0;',
]),
'',
Conditional(self.opt, '', self.opt.poly is None, [
'cfg->poly &= {cfg_mask};'.format(**self.sym),
]),
Conditional(self.opt, '', self.opt.xor_in is None, [
'cfg->xor_in &= {cfg_mask};'.format(**self.sym),
]),
Conditional(self.opt, '', self.opt.xor_out is None, [
'cfg->xor_out &= {cfg_mask};'.format(**self.sym),
]),
'return 0;',
]),
'}',
]
return CodeGen(self.opt, '', out)
def _includes(opt):
"""
Return the #include directives for the user-defined list of include files.
"""
includes = []
if opt.include_files is not None and len(opt.include_files) > 0:
for include_file in opt.include_files:
if include_file[0] == '"' or include_file[0] == '<':
includes.append('#include {0}'.format(include_file))
else:
includes.append('#include "{0}"'.format(include_file))
return includes
def _crc_algo_define(opt, sym):
"""
Get the the identifier for header files.
"""
name = sym['crc_algorithm'].upper().replace('-', '_')
return 'CRC_ALGO_' + name
def _use_cfg(opt):
"""
Return True if a cfg_t structure is to be used.
"""
return opt.undefined_crc_parameters
def _use_constant_crc_init(sym):
"""
Return True if the inintial value is constant.
"""
return sym['crc_init_value'] is not None
def _use_reflect_func(opt):
"""
Return True if the reflect function is to be used.
"""
if opt.reflect_out == None or opt.reflect_in == None:
return True
elif opt.algorithm == opt.algo_table_driven:
if opt.reflect_in != opt.reflect_out:
return True
elif opt.algorithm == opt.algo_bit_by_bit:
if opt.reflect_in:
return True
if opt.reflect_out:
return True
elif opt.algorithm == opt.algo_bit_by_bit_fast:
if opt.reflect_in:
return True
if opt.reflect_out:
return True
return False
def _use_static_reflect_func(opt):
"""
Whether a static reflect function is to be used.
"""
if opt.algorithm == opt.algo_table_driven:
return False
elif opt.reflect_out is not None and opt.algorithm == opt.algo_bit_by_bit_fast:
return False
else:
return True
def _use_crc_table_gen(opt):
"""
Return True if the table generator function is to be generated.
"""
if opt.algorithm == opt.algo_table_driven:
return opt.width is None or opt.poly is None or opt.reflect_in is None
else:
return False
def _crc_init_function_def(opt, sym):
"""
The definition for the init function.
"""
if _use_constant_crc_init(sym):
return '{crc_t} {crc_init_function}(void)'.format(**sym)
else:
return '{crc_t} {crc_init_function}(const {cfg_t} *cfg)'.format(**sym)
def _use_cfg_in_crc_update(opt):
"""
Return True if the update function uses the cfg_t parameter.
"""
if opt.algorithm in set([opt.algo_bit_by_bit, opt.algo_bit_by_bit_fast]):
if opt.width is not None and opt.poly is not None and opt.reflect_in is not None:
return True
elif opt.algorithm == opt.algo_table_driven:
if opt.width is not None and opt.reflect_in is not None:
return True
return False
def _crc_update_function_def(opt, sym):
"""
The definition of the update function.
"""
if _use_cfg_in_crc_update(opt):
return '{crc_t} {crc_update_function}({crc_t} crc, const void *data, size_t data_len)'.format(**sym)
else:
return '{crc_t} {crc_update_function}(const {cfg_t} *cfg, {crc_t} crc, const void *data, size_t data_len)'.format(**sym)
def _use_cfg_in_finalize(opt):
"""
Return True if the cfg_t parameter is used in the finalize function.
"""
if opt.algorithm == opt.algo_bit_by_bit:
if opt.width is not None and opt.poly is not None and opt.reflect_out is not None and opt.xor_out is not None:
return True
elif opt.algorithm == opt.algo_bit_by_bit_fast:
if opt.width is not None and opt.reflect_out is not None and opt.xor_out is not None:
return True
elif opt.algorithm == opt.algo_table_driven:
if opt.width is not None and opt.reflect_in is not None and opt.reflect_out is not None and opt.xor_out is not None:
return True
return False
def _use_inline_crc_finalize(opt):
"""
Return True if the init function can be inlined.
"""
if opt.algorithm in set([opt.algo_bit_by_bit_fast, opt.algo_table_driven]) and \
(opt.width is not None and opt.reflect_in is not None and opt.reflect_out is not None and opt.xor_out is not None):
return True
else:
return False
def _use_constant_crc_table(opt):
"""
Return True is the CRC table is constant.
"""
if opt.width is not None and opt.poly is not None and opt.reflect_in is not None:
return True
else:
return False
def _crc_finalize_function_def(opt, sym):
"""
The definition of the finalize function.
"""
if _use_cfg_in_finalize(opt):
return '{crc_t} {crc_finalize_function}({crc_t} crc)'.format(**sym)
else:
return '{crc_t} {crc_finalize_function}(const {cfg_t} *cfg, {crc_t} crc)'.format(**sym)
def _crc_final_value(opt, sym):
"""
The return value for the finalize function.
"""
if opt.algorithm == opt.algo_table_driven:
if opt.reflect_in == opt.reflect_out:
return expr.Xor('crc', sym['crc_xor_out']).simplify()
else:
reflect_fun = expr.FunctionCall(sym['crc_reflect_function'], ['crc', sym['crc_width']])
return expr.Xor(reflect_fun, sym['crc_xor_out']).simplify()
elif opt.reflect_out:
reflect_fun = expr.FunctionCall(sym['crc_reflect_function'], ['crc', sym['crc_width']])
return expr.Xor(reflect_fun, sym['crc_xor_out']).simplify()
else:
return expr.Xor('crc', sym['crc_xor_out']).simplify()
def _crc_table(opt, sym):
"""
Return the code for the CRC table or the generator function.
"""
if opt.algorithm != opt.algo_table_driven:
return []
return [
'', '',
Comment(opt, '', [
'Static table used for the table_driven implementation.',
Conditional(opt, '', opt.undefined_crc_parameters, [
'Must be initialised with the {crc_table_gen_function} function.'.format(**sym),
]),
]),
Conditional2(opt, '', _use_constant_crc_table(opt), [
Conditional2(opt, '', opt.slice_by > 1, [
'static const {crc_t} crc_table[{crc_slice_by}][{crc_table_width}] = {crc_table_init};'.format(**sym),
], [
'static const {crc_t} crc_table[{crc_table_width}] = {crc_table_init};'.format(**sym),
]),
], [
'static {crc_t} crc_table[{crc_table_width}];'.format(**sym),
]),
]
def _crc_table_gen(opt, sym):
"""
Return the code for the CRC table or the generator function.
"""
if opt.algorithm != opt.algo_table_driven or _use_constant_crc_table(opt):
return []
return [
'', '',
'void {crc_table_gen_function}(const {cfg_t} *cfg)'.format(**sym),
'{',
CodeGen(opt, 4*' ', [
'{crc_t} crc;'.format(**sym),
'unsigned int i, j;',
'',
'for (i = 0; i < {cfg_table_width}; i++) '.format(**sym) + '{',
CodeGen(opt, 4*' ', [
Conditional2(opt, '', opt.reflect_in is None, [
'if (cfg->reflect_in) {',
CodeGen(opt, 4*' ', [
'crc = {crc_reflect_function}(i, {cfg_table_idx_width});'.format(**sym),
]),
'} else {',
CodeGen(opt, 4*' ', [
'crc = i;',
]),
'}',
], [
Conditional2(opt, '', opt.reflect_in, [
'crc = {crc_reflect_function}(i, {cfg_table_idx_width});'.format(**sym),
], [
'crc = i;',
]),
]),
'crc <<= {0};'.format(expr.Parenthesis(expr.Add(expr.Sub(sym['cfg_width'], sym['cfg_table_idx_width']), sym['cfg_shift'])).simplify()),
'for (j = 0; j < {cfg_table_idx_width}; j++) '.format(**sym) + '{',
CodeGen(opt, 4*' ', [
'if (crc & {cfg_msb_mask_shifted}) '.format(**sym) + '{',
CodeGen(opt, 4*' ', [
'crc = {0};'.format(expr.Xor(expr.Parenthesis(expr.Shl('crc', 1)), sym['cfg_poly_shifted']).simplify()),
]),
'} else {',
CodeGen(opt, 4*' ', [
'crc = crc << 1;',
]),
'}',
]),
'}',
Conditional(opt, '', opt.reflect_in is None, [
'if (cfg->reflect_in) {',
Conditional2(opt, 4*' ', sym.tbl_shift is None or sym.tbl_shift > 0, [
'crc = {0};'.format(expr.Shl(expr.FunctionCall(sym['crc_reflect_function'], [expr.Shr('crc', sym['cfg_shift']), sym['cfg_width']]), sym['cfg_shift']).simplify()),
], [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]),
'}',
]),
Conditional(opt, '', opt.reflect_in, [
Conditional2(opt, 4*' ', sym.tbl_shift is None or sym.tbl_shift > 0, [
'crc = {0};'.format(expr.Shl(expr.FunctionCall(sym['crc_reflect_function'], [expr.Shr('crc', sym['cfg_shift']), sym['cfg_width']]), sym['cfg_shift']).simplify()),
], [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]),
]),
'crc_table[i] = {0};'.format(expr.Shr(expr.Parenthesis(expr.And('crc', sym['cfg_mask_shifted'])), sym['cfg_shift'])),
]),
'}',
]),
'}',
]
def _crc_reflect_function_gen(opt, sym):
"""
Return the code for the reflect functon.
"""
if not _use_reflect_func(opt):
return []
if not (opt.reflect_in is None or opt.reflect_in or \
opt.reflect_out is None or opt.reflect_out):
return []
return [
'', '',
'{crc_t} {crc_reflect_function}({crc_t} data, size_t data_len)'.format(**sym),
'{',
CodeGen(opt, 4*' ', [
'unsigned int i;',
'{crc_t} ret;'.format(**sym),
'',
'ret = data & 0x01;',
'for (i = 1; i < data_len; i++) {',
CodeGen(opt, 4*' ', [
'data >>= 1;',
'ret = (ret << 1) | (data & 0x01);',
]),
'}',
'return ret;',
]),
'}',
]
def _crc_init_function_gen(opt, sym):
"""
Return the code for the init function.
"""
if _use_constant_crc_init(sym):
return []
out = [
'', '',
_crc_init_function_def(opt, sym),
'{',
CodeGen(opt, 4*' ', [
Conditional(opt, '', opt.algorithm == opt.algo_bit_by_bit, [
'unsigned int i;',
'{c_bool} bit;'.format(**sym),
'{crc_t} crc = {cfg_xor_in};'.format(**sym),
'for (i = 0; i < {cfg_width}; i++) '.format(**sym) + '{',
CodeGen(opt, 4*' ', [
'bit = crc & 0x01;',
'if (bit) {',
CodeGen(opt, 4*' ', [
'crc = ((crc ^ {cfg_poly}) >> 1) | {cfg_msb_mask};'.format(**sym),
]),
'} else {',
CodeGen(opt, 4*' ', [
'crc >>= 1;',
]),
'}',
]),
'}',
'return crc & {cfg_mask};'.format(**sym),
]),
Conditional(opt, '', opt.algorithm == opt.algo_bit_by_bit_fast, [
'return {cfg_xor_in} & {cfg_mask};'.format(**sym),
]),
Conditional(opt, '', opt.algorithm == opt.algo_table_driven, [
Conditional2(opt, '', opt.reflect_in is None, [
'if ({cfg_reflect_in}) '.format(**sym) + '{',
CodeGen(opt, 4*' ', [
'return {crc_reflect_function}({cfg_xor_in} & {cfg_mask}, {cfg_width});'.format(**sym),
]),
'} else {',
CodeGen(opt, 4*' ', [
'return {cfg_xor_in} & {cfg_mask};'.format(**sym),
]),
'}',
], [
Conditional2(opt, '', opt.algorithm == opt.reflect_in, [
'return {crc_reflect_function}({cfg_xor_in} & {cfg_mask}, {cfg_width});'.format(**sym),
], [
'return {cfg_xor_in} & {cfg_mask};'.format(**sym),
]),
]),
]),
]),
'}',
]
return out
def _crc_update_function_gen(opt, sym):
"""
Return the code for the update function.
"""
out = [
'', '',
_crc_update_function_def(opt, sym),
'{',
CodeGen(opt, 4*' ', [ 'const unsigned char *d = (const unsigned char *)data;' ]),
]
if opt.algorithm == opt.algo_bit_by_bit:
out += [
CodeGen(opt, 4*' ', [
'unsigned int i;',
'{c_bool} bit;'.format(**sym),
'unsigned char c;',
'',
'while (data_len--) {',
Conditional2(opt, 4*' ', opt.reflect_in is None, [
'if (' + sym['cfg_reflect_in'] + ') {',
CodeGen(opt, 4*' ', [
'c = {crc_reflect_function}(*d++, 8);'.format(**sym),
]),
'} else {',
CodeGen(opt, 4*' ', [
'c = *d++;',
]),
'}',
], [
Conditional2(opt, '', opt.reflect_in, [
'c = {crc_reflect_function}(*d++, 8);'.format(**sym),
], [
'c = *d++;',
]),
]),
CodeGen(opt, 4*' ', [
'for (i = 0; i < 8; i++) {',
CodeGen(opt, 4*' ', [
Conditional2(opt, '', opt.c_std == 'C89', [
'bit = !!(crc & {cfg_msb_mask});'.format(**sym),
], [
'bit = crc & {cfg_msb_mask};'.format(**sym),
]),
'crc = (crc << 1) | ((c >> (7 - i)) & 0x01);',
'if (bit) {',
CodeGen(opt, 4*' ', [
'crc ^= {cfg_poly};'.format(**sym),
]),
'}',
]),
'}',
'crc &= {cfg_mask};'.format(**sym),
]),
'}',
'return crc & {cfg_mask};'.format(**sym),
]),
]
if opt.algorithm == opt.algo_bit_by_bit_fast:
out += [
CodeGen(opt, 4*' ', [
'unsigned int i;',
'{c_bool} bit;'.format(**sym),
'unsigned char c;',
'',
'while (data_len--) {',
CodeGen(opt, 4*' ', [
Conditional2(opt, '', opt.reflect_in == None, [
'if (' + sym['cfg_reflect_in'] + ') {',
CodeGen(opt, 4*' ', [
'c = {crc_reflect_function}(*d++, 8);'.format(**sym),
]),
'} else {',
CodeGen(opt, 4*' ', [
'c = *d++;',
]),
'}',
], [
'c = *d++;',
]),
Conditional2(opt, '', opt.reflect_in, [
'for (i = 0x01; i & 0xff; i <<= 1) {',
], [
'for (i = 0x80; i > 0; i >>= 1) {',
]),
CodeGen(opt, 4*' ', [
Conditional2(opt, '', opt.c_std == 'C89', [
'bit = !!({0});'.format(expr.And('crc', sym['cfg_msb_mask']).simplify()),
], [
'bit = {0};'.format(expr.And('crc', sym['cfg_msb_mask']).simplify()),
]),
'if (c & i) {',
CodeGen(opt, 4*' ', [
'bit = !bit;',
]),
'}',
'crc <<= 1;',
'if (bit) {',
CodeGen(opt, 4*' ', [
'crc ^= {cfg_poly};'.format(**sym),
]),
'}',
]),
'}',
'crc &= {cfg_mask};'.format(**sym)
]),
'}',
'return {0};'.format(expr.And('crc', sym['cfg_mask']).simplify()),
]),
]
if opt.algorithm == opt.algo_table_driven:
out += [
CodeGen(opt, 4*' ', [
'unsigned int tbl_idx;',
'',
Conditional2(opt, '', opt.reflect_in == None, [
'if (cfg->reflect_in) {',
CodeGen(opt, 4*' ', [
'while (data_len--) {',
CodeGen(opt, 4*' ', [
_crc_table_core_algorithm_reflected(opt, sym),
'd++;',
]),
'}',
]),
'} else {',
CodeGen(opt, 4*' ', [
'while (data_len--) {',
CodeGen(opt, 4*' ', [
_crc_table_core_algorithm_nonreflected(opt, sym),
'd++;',
]),
'}',
]),
'}',
], [
Conditional(opt, '', opt.slice_by > 1, [
'/* Align to a multiple of {crc_slice_by} bytes */'.format(**sym),
'while (data_len && (((uintptr_t)(const void *)d) % {crc_slice_by} != 0))'.format(**sym) + ' {',
CodeGen(opt, 4*' ', [
_crc_table_core_algorithm(opt, sym),
'data_len--;',
]),
'}',
'',
_crc_table_slice_by_algorithm(opt, sym),
'/* Remaining bytes with the standard algorithm */',
'd = (const unsigned char *)d32;',
]),
'while (data_len--) {',
CodeGen(opt, 4*' ', [
_crc_table_core_algorithm(opt, sym),
]),
'}',
]),
'return {0};'.format(expr.And('crc', sym['cfg_mask']).simplify()),
]),
]
out += [
'}',
]
return out
def _crc_finalize_function_gen(opt, sym):
"""
Return the code for the finalize function.
"""
if _use_inline_crc_finalize(opt):
return []
out = [
'', '',
_crc_finalize_function_def(opt, sym),
'{',
]
if opt.algorithm in set([opt.algo_bit_by_bit, opt.algo_bit_by_bit_fast]):
out += [
Conditional(opt, 4*' ', opt.algorithm == opt.algo_bit_by_bit, [
'unsigned int i;',
'{c_bool} bit;'.format(**sym),
'',
'for (i = 0; i < ' + sym['cfg_width'] + '; i++) {',
CodeGen(opt, 4*' ', [
Conditional2(opt, '', opt.c_std == 'C89', [
'bit = !!(crc & {cfg_msb_mask});'.format(**sym)
], [
'bit = crc & {cfg_msb_mask};'.format(**sym),
]),
'crc <<= 1;',
'if (bit) {',
CodeGen(opt, 4*' ', [
'crc ^= {cfg_poly};'.format(**sym),
]),
'}',
]),
'}',
Conditional(opt, '', opt.reflect_out is None, [
'if (' + sym['cfg_reflect_out'] + ') {',
CodeGen(opt, 4*' ', [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]),
'}',
]),
Conditional(opt, '', opt.reflect_out, [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]),
]),
Conditional(opt, 4*' ', opt.algorithm == opt.algo_bit_by_bit_fast, [
Conditional(opt, '', opt.reflect_out is None, [
'if (' + sym['cfg_reflect_out'] + ') {',
CodeGen(opt, 4*' ', [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]),
'}',
]),
Conditional(opt, '', opt.reflect_out, [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]),
]),
]
if opt.algorithm == opt.algo_table_driven:
if opt.reflect_in is None or opt.reflect_out is None:
if opt.reflect_in is None and opt.reflect_out is None:
cond = 'cfg->reflect_in != cfg->reflect_out'
elif opt.reflect_out is None:
cond = '!' if opt.reflect_in else '' + 'cfg->reflect_out'
else:
cond = '!' if opt.reflect_out else '' + 'cfg->reflect_in'
out += [
CodeGen(opt, 4*' ', [
'if (' + cond + ') {',
CodeGen(opt, 4*' ', [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]),
'}',
]),
]
elif opt.reflect_in != opt.reflect_out:
out += [
'crc = {crc_reflect_function}(crc, {cfg_width});'.format(**sym),
]
out += [
CodeGen(opt, 4*' ', [
'return {0};'.format(expr.And(expr.Parenthesis(expr.Xor('crc', sym['cfg_xor_out'])), sym['cfg_mask']).simplify()),
]),
'}',
]
return out
def _crc_table_core_algorithm(opt, sym):
"""
Return the core of the table-driven algorithm.
"""
out = []
out += [
Conditional2(opt, '', opt.reflect_in, [
_crc_table_core_algorithm_reflected(opt, sym),
], [
_crc_table_core_algorithm_nonreflected(opt, sym),
]),
'd++;',
]
return CodeGen(opt, '', out)
def _crc_table_core_algorithm_reflected(opt, sym):
"""
Return the core loop of the table-driven algorithm, reflected variant.
"""
out = []
if opt.width is not None and opt.tbl_idx_width is not None and opt.width <= opt.tbl_idx_width:
crc_xor_expr = '0'
else:
crc_xor_expr = '(crc >> {cfg_table_idx_width})'.format(**sym)
if opt.tbl_idx_width == 8:
if opt.slice_by > 1:
crc_lookup = 'crc_table[0][tbl_idx]'
else:
crc_lookup = 'crc_table[tbl_idx]'
out += [
Conditional2(opt, '', opt.width is None or opt.width > 8, [
'tbl_idx = (crc ^ *d) & {crc_table_mask};'.format(**sym),
], [
'tbl_idx = crc ^ *d;',
]),
'crc = {0};'.format(expr.And(expr.Parenthesis(expr.Xor(crc_lookup, expr.Parenthesis(expr.Shr('crc', sym['cfg_table_idx_width'])))), sym['cfg_mask']).simplify()),
]
else:
crc_lookup = 'crc_table[tbl_idx & {crc_table_mask}]'.format(**sym)
for i in range(8 // opt.tbl_idx_width):
out += [
'tbl_idx = {0};'.format(expr.Xor('crc', expr.Parenthesis(expr.Shr('*d', expr.Parenthesis(expr.Mul(i, sym['cfg_table_idx_width']))))).simplify()),
'crc = {0};'.format(expr.Xor(crc_lookup, crc_xor_expr).simplify())
]
return CodeGen(opt, '', out)
def _crc_table_core_algorithm_nonreflected(opt, sym):
"""
Return the core loop of the table-driven algorithm, non-reflected variant.
"""
out = []
if opt.width == None:
crc_shifted_right = expr.Parenthesis(expr.Shr('crc', expr.Parenthesis(expr.Sub(sym['cfg_width'], sym['cfg_table_idx_width'])))).simplify()
elif opt.width < 8:
shift_val = opt.width - opt.tbl_idx_width
if shift_val < 0:
crc_shifted_right = expr.Parenthesis(expr.Shl('crc', -shift_val)).simplify()
else:
crc_shifted_right = expr.Parenthesis(expr.Shr('crc', shift_val)).simplify()
else:
shift_val = opt.width - opt.tbl_idx_width
crc_shifted_right = expr.Parenthesis(expr.Shr('crc', shift_val)).simplify()
if opt.width is not None and opt.tbl_idx_width is not None and opt.width <= opt.tbl_idx_width:
crc_xor_expr = '0'
else:
crc_xor_expr = '(crc << {cfg_table_idx_width})'.format(**sym)
if opt.tbl_idx_width == 8:
if opt.slice_by > 1:
crc_lookup = 'crc_table[0][tbl_idx]'
else:
crc_lookup = 'crc_table[tbl_idx]'
out += [
Conditional2(opt, '', opt.width is None or opt.width > 8, [
'tbl_idx = {0};'.format(expr.And(expr.Parenthesis(expr.Xor(crc_shifted_right, '*d')), sym['crc_table_mask']).simplify())
], [
'tbl_idx = {0};'.format(expr.Xor(crc_shifted_right, '*d').simplify())
]),
'crc = {0};'.format(expr.And(expr.Parenthesis(expr.Xor(crc_lookup, crc_xor_expr)), sym['cfg_mask']).simplify())
]
else:
crc_lookup = 'crc_table[tbl_idx & {crc_table_mask}]'.format(**sym)
for i in range(8 // opt.tbl_idx_width):
str_idx = '{0:d}'.format(8 - (i + 1) * opt.tbl_idx_width)
out += [
'tbl_idx = {0};'.format(expr.Xor(crc_shifted_right, expr.Parenthesis(expr.Shr('*d', str_idx)))),
'crc = {0};'.format(expr.Xor(crc_lookup, crc_xor_expr).simplify()),
]
return CodeGen(opt, '', out)
def _crc_table_slice_by_algorithm(opt, sym):
update_be = []
for i in range(opt.slice_by // 4):
vard = 'd{0}'.format(opt.slice_by // 4 - i)
for j in range(4):
idx1 = i * 4 + j
idx2 = expr.And(expr.Parenthesis(expr.Shr(vard, j*8)), expr.Terminal(255, '0xffu')).simplify()
update_be.append('crc_table[{0}][{1}]{2}'.format(idx1, idx2, ' ^' if idx1 < opt.slice_by - 1 else ';'))
update_le = []
for i in range(opt.slice_by // 4):
vard = 'd{0}'.format(opt.slice_by // 4 - i)
for j in range(4):
idx1 = i * 4 + j
idx2 = expr.And(expr.Parenthesis(expr.Shr(vard, 24 - j*8)), expr.Terminal(255, '0xffu')).simplify()
update_le.append('crc_table[{0}][{1}]{2}'.format(idx1, idx2, ' ^' if idx1 < opt.slice_by - 1 else ';'))
out = [
'const uint32_t *d32 = (const uint32_t *)d;',
'while (data_len >= {crc_slice_by})'.format(**sym),
'{',
CodeGen(opt, 4*' ', [
CodeGen(opt, None, [
'#if __BYTE_ORDER == __BIG_ENDIAN',
]),
'{crc_t} d1 = *d32++ ^ le16toh(crc);'.format(**sym),
Conditional(opt, '', opt.slice_by >= 8, [
'{crc_t} d2 = *d32++;'.format(**sym),
]),
Conditional(opt, '', opt.slice_by >= 16, [
'{crc_t} d3 = *d32++;'.format(**sym),
'{crc_t} d4 = *d32++;'.format(**sym),
]),
'crc =',
CodeGen(opt, 4*' ', update_be),
CodeGen(opt, None, [
'#else',
]),
'{crc_t} d1 = *d32++ ^ crc;'.format(**sym),
Conditional(opt, '', opt.slice_by >= 8, [
'{crc_t} d2 = *d32++;'.format(**sym),
]),
Conditional(opt, '', opt.slice_by >= 16, [
'{crc_t} d3 = *d32++;'.format(**sym),
'{crc_t} d4 = *d32++;'.format(**sym),
]),
'crc =',
CodeGen(opt, 4*' ', update_le),
CodeGen(opt, None, [
'#endif',
]),
'',
'data_len -= {crc_slice_by};'.format(**sym),
]),
'}',
'',
]
return CodeGen(opt, '', out)