| commit | abbd523bae6e75545ccff126a4a47218ec0defab | [log] [tgz] |
|---|---|---|
| author | Rob Herring <robh@kernel.org> | Wed Feb 01 16:44:41 2023 -0600 |
| committer | David Gibson <david@gibson.dropbear.id.au> | Thu Feb 02 16:32:47 2023 +1100 |
| tree | b84b4d64152ea595b881944cd6a71137e83e8968 | |
| parent | a41509bea3e73b8dc63bf666a82275bc7d040266 [diff] |
pylibfdt: Work-around SWIG limitations with flexible arrays
Commit a41509bea3e7 ("libfdt: Replace deprecated 0-length arrays with
proper flexible arrays") fails to build pylibfdt:
./pylibfdt/libfdt_wrap.c: In function ‘_wrap_fdt_node_header_name_set’:
./pylibfdt/libfdt_wrap.c:4350:18: error: cast specifies array type
4350 | arg1->name = (char [])(char *)memcpy(malloc((size)*sizeof(char)), (const char *)(arg2), sizeof(char)*(size));
| ^
./pylibfdt/libfdt_wrap.c:4350:16: error: invalid use of flexible array member
4350 | arg1->name = (char [])(char *)memcpy(malloc((size)*sizeof(char)), (const char *)(arg2), sizeof(char)*(size));
| ^
./pylibfdt/libfdt_wrap.c:4352:16: error: invalid use of flexible array member
4352 | arg1->name = 0;
| ^
./pylibfdt/libfdt_wrap.c: In function ‘_wrap_fdt_property_data_set’:
./pylibfdt/libfdt_wrap.c:4613:18: error: cast specifies array type
4613 | arg1->data = (char [])(char *)memcpy(malloc((size)*sizeof(char)), (const char *)(arg2), sizeof(char)*(size));
| ^
./pylibfdt/libfdt_wrap.c:4613:16: error: invalid use of flexible array member
4613 | arg1->data = (char [])(char *)memcpy(malloc((size)*sizeof(char)), (const char *)(arg2), sizeof(char)*(size));
| ^
./pylibfdt/libfdt_wrap.c:4615:16: error: invalid use of flexible array member
4615 | arg1->data = 0;
| ^
Turns out this is known issue with SWIG: https://github.com/swig/swig/issues/1699
Implement the work-around to ignore the flexible array member.
Fixes: a41509bea3e7 ("libfdt: Replace deprecated 0-length arrays with proper flexible arrays")
Cc: Kees Cook <keescook@chromium.org>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Message-Id: <20230201224441.305757-1-robh@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The source tree contains the Device Tree Compiler (dtc) toolchain for working with device tree source and binary files and also libfdt, a utility library for reading and manipulating the binary format.
dtc and libfdt are maintained by:
A Python library wrapping libfdt is also available. To build this you will need to install swig and Python development files. On Debian distributions:
$ sudo apt-get install swig python3-dev
The library provides an Fdt class which you can use like this:
$ PYTHONPATH=../pylibfdt python3
>>> import libfdt
>>> fdt = libfdt.Fdt(open('test_tree1.dtb', mode='rb').read())
>>> node = fdt.path_offset('/subnode@1')
>>> print(node)
124
>>> prop_offset = fdt.first_property_offset(node)
>>> prop = fdt.get_property_by_offset(prop_offset)
>>> print('%s=%s' % (prop.name, prop.as_str()))
compatible=subnode1
>>> node2 = fdt.path_offset('/')
>>> print(fdt.getprop(node2, 'compatible').as_str())
test_tree1
You will find tests in tests/pylibfdt_tests.py showing how to use each method. Help is available using the Python help command, e.g.:
$ cd pylibfdt $ python3 -c "import libfdt; help(libfdt)"
If you add new features, please check code coverage:
$ sudo apt-get install python3-coverage $ cd tests # It's just 'coverage' on most other distributions $ python3-coverage run pylibfdt_tests.py $ python3-coverage html # Open 'htmlcov/index.html' in your browser
The library can be installed with pip from a local source tree:
$ pip install . [--user|--prefix=/path/to/install_dir]
Or directly from a remote git repo:
$ pip install git+git://git.kernel.org/pub/scm/utils/dtc/dtc.git@main
The install depends on libfdt shared library being installed on the host system first. Generally, using --user or --prefix is not necessary and pip will use the default location for the Python installation which varies if the user is root or not.
You can also install everything via make if you like, but pip is recommended.
To install both libfdt and pylibfdt you can use:
$ make install [PREFIX=/path/to/install_dir]
To disable building the python library, even if swig and Python are available, use:
$ make NO_PYTHON=1
More work remains to support all of libfdt, including access to numeric values.