Move get_c_expression_values into a separate module

Create a directory mbedtls_dev intended to contain various Python
module for use by Python scripts located anywhere in the Mbed TLS
source tree.

Move get_c_expression_values and its auxiliary functions into a new
Python module mbedtls_dev.c_build_helper.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2020-12-11 00:30:53 +01:00
parent fc62211e3b
commit 2adebc89da
2 changed files with 142 additions and 118 deletions

View file

@ -0,0 +1,138 @@
"""Generate and run C code.
"""
# 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 os
import platform
import subprocess
import sys
import tempfile
def remove_file_if_exists(filename):
"""Remove the specified file, ignoring errors."""
if not filename:
return
try:
os.remove(filename)
except OSError:
pass
def create_c_file(file_label):
"""Create a temporary C file.
* ``file_label``: a string that will be included in the file name.
Return ```(c_file, c_name, exe_name)``` where ``c_file`` is a Python
stream open for writing to the file, ``c_name`` is the name of the file
and ``exe_name`` is the name of the executable that will be produced
by compiling the file.
"""
c_fd, c_name = tempfile.mkstemp(prefix='tmp-{}-'.format(file_label),
suffix='.c')
exe_suffix = '.exe' if platform.system() == 'Windows' else ''
exe_name = c_name[:-2] + exe_suffix
remove_file_if_exists(exe_name)
c_file = os.fdopen(c_fd, 'w', encoding='ascii')
return c_file, c_name, exe_name
def generate_c_printf_expressions(c_file, cast_to, printf_format, expressions):
"""Generate C instructions to print the value of ``expressions``.
Write the code with ``c_file``'s ``write`` method.
Each expression is cast to the type ``cast_to`` and printed with the
printf format ``printf_format``.
"""
for expr in expressions:
c_file.write(' printf("{}\\n", ({}) {});\n'
.format(printf_format, cast_to, expr))
def generate_c_file(c_file,
caller, header,
main_generator):
"""Generate a temporary C source file.
* ``c_file`` is an open stream on the C source file.
* ``caller``: an informational string written in a comment at the top
of the file.
* ``header``: extra code to insert before any function in the generated
C file.
* ``main_generator``: a function called with ``c_file`` as its sole argument
to generate the body of the ``main()`` function.
"""
c_file.write('/* Generated by {} */'
.format(caller))
c_file.write('''
#include <stdio.h>
''')
c_file.write(header)
c_file.write('''
int main(void)
{
''')
main_generator(c_file)
c_file.write(''' return 0;
}
''')
def get_c_expression_values(
cast_to, printf_format,
expressions,
caller=__name__, file_label='',
header='', include_path=None,
keep_c=False,
): # pylint: disable=too-many-arguments
"""Generate and run a program to print out numerical values for expressions.
* ``cast_to``: a C type.
* ``printf_format``: a printf format suitable for the type ``cast_to``.
* ``header``: extra code to insert before any function in the generated
C file.
* ``expressions``: a list of C language expressions that have the type
``type``.
* ``include_path``: a list of directories containing header files.
* ``keep_c``: if true, keep the temporary C file (presumably for debugging
purposes).
Return the list of values of the ``expressions``.
"""
if include_path is None:
include_path = []
c_name = None
exe_name = None
try:
c_file, c_name, exe_name = create_c_file(file_label)
generate_c_file(
c_file, caller, header,
lambda c_file: generate_c_printf_expressions(c_file,
cast_to, printf_format,
expressions)
)
c_file.close()
cc = os.getenv('CC', 'cc')
subprocess.check_call([cc] +
['-I' + dir for dir in include_path] +
['-o', exe_name, c_name])
if keep_c:
sys.stderr.write('List of {} tests kept at {}\n'
.format(caller, c_name))
else:
os.remove(c_name)
output = subprocess.check_output([exe_name])
return output.decode('ascii').strip().split('\n')
finally:
remove_file_if_exists(exe_name)

View file

@ -26,11 +26,12 @@ import argparse
from collections import namedtuple
import itertools
import os
import platform
import re
import subprocess
import sys
import tempfile
import scripts_path # pylint: disable=unused-import
from mbedtls_dev import c_build_helper
class ReadFileLineException(Exception):
def __init__(self, filename, line_number):
@ -304,121 +305,6 @@ def gather_inputs(headers, test_suites, inputs_class=Inputs):
inputs.gather_arguments()
return inputs
def remove_file_if_exists(filename):
"""Remove the specified file, ignoring errors."""
if not filename:
return
try:
os.remove(filename)
except OSError:
pass
def create_c_file(file_label):
"""Create a temporary C file.
* ``file_label``: a string that will be included in the file name.
Return ```(c_file, c_name, exe_name)``` where ``c_file`` is a Python
stream open for writing to the file, ``c_name`` is the name of the file
and ``exe_name`` is the name of the executable that will be produced
by compiling the file.
"""
c_fd, c_name = tempfile.mkstemp(prefix='tmp-{}-'.format(file_label),
suffix='.c')
exe_suffix = '.exe' if platform.system() == 'Windows' else ''
exe_name = c_name[:-2] + exe_suffix
remove_file_if_exists(exe_name)
c_file = os.fdopen(c_fd, 'w', encoding='ascii')
return c_file, c_name, exe_name
def generate_c_printf_expressions(c_file, cast_to, printf_format, expressions):
"""Generate C instructions to print the value of ``expressions``.
Write the code with ``c_file``'s ``write`` method.
Each expression is cast to the type ``cast_to`` and printed with the
printf format ``printf_format``.
"""
for expr in expressions:
c_file.write(' printf("{}\\n", ({}) {});\n'
.format(printf_format, cast_to, expr))
def generate_c_file(c_file,
caller, header,
main_generator):
"""Generate a temporary C source file.
* ``c_file`` is an open stream on the C source file.
* ``caller``: an informational string written in a comment at the top
of the file.
* ``header``: extra code to insert before any function in the generated
C file.
* ``main_generator``: a function called with ``c_file`` as its sole argument
to generate the body of the ``main()`` function.
"""
c_file.write('/* Generated by {} */'
.format(caller))
c_file.write('''
#include <stdio.h>
''')
c_file.write(header)
c_file.write('''
int main(void)
{
''')
main_generator(c_file)
c_file.write(''' return 0;
}
''')
def get_c_expression_values(
cast_to, printf_format,
expressions,
caller=__name__, file_label='',
header='', include_path=None,
keep_c=False,
): # pylint: disable=too-many-arguments
"""Generate and run a program to print out numerical values for expressions.
* ``cast_to``: a C type.
* ``printf_format``: a printf format suitable for the type ``cast_to``.
* ``header``: extra code to insert before any function in the generated
C file.
* ``expressions``: a list of C language expressions that have the type
``type``.
* ``include_path``: a list of directories containing header files.
* ``keep_c``: if true, keep the temporary C file (presumably for debugging
purposes).
Return the list of values of the ``expressions``.
"""
if include_path is None:
include_path = []
c_name = None
exe_name = None
try:
c_file, c_name, exe_name = create_c_file(file_label)
generate_c_file(
c_file, caller, header,
lambda c_file: generate_c_printf_expressions(c_file,
cast_to, printf_format,
expressions)
)
c_file.close()
cc = os.getenv('CC', 'cc')
subprocess.check_call([cc] +
['-I' + dir for dir in include_path] +
['-o', exe_name, c_name])
if keep_c:
sys.stderr.write('List of {} tests kept at {}\n'
.format(caller, c_name))
else:
os.remove(c_name)
output = subprocess.check_output([exe_name])
return output.decode('ascii').strip().split('\n')
finally:
remove_file_if_exists(exe_name)
def run_c(type_word, expressions, include_path=None, keep_c=False):
"""Generate and run a program to print out numerical values for expressions."""
if type_word == 'status':
@ -427,7 +313,7 @@ def run_c(type_word, expressions, include_path=None, keep_c=False):
else:
cast_to = 'unsigned long'
printf_format = '0x%08lx'
return get_c_expression_values(
return c_build_helper.get_c_expression_values(
cast_to, printf_format,
expressions,
caller='test_psa_constant_names.py for {} values'.format(type_word),