This adds support to generate SPDX 2.2 tag-value documents via the
new west spdx command. The CMake file-based APIs are leveraged to
create relationships from source files to the corresponding
generated build files. SPDX-License-Identifier comments in source
files are scanned and filled into the SPDX documents.
Before `west build` is run, a specific file must be created in the
build directory so that the CMake API reply will run. This can be
done by running:
west spdx --init -d BUILD_DIR
After `west build` is run, SPDX generation is then activated by
calling `west spdx`; currently this requires passing the build
directory as a parameter again:
west spdx -d BUILD_DIR
This will generate three SPDX documents in `BUILD_DIR/spdx/`:
1) `app.spdx`: This contains the bill-of-materials for the
application source files used for the build.
2) `zephyr.spdx`: This contains the bill-of-materials for the
specific Zephyr source code files that are used for the build.
3) `build.spdx`: This contains the bill-of-materials for the built
output files.
Each file in the bill-of-materials is scanned, so that its hashes
(SHA256 and SHA1) can be recorded, along with any detected licenses
if an `SPDX-License-Identifier` appears in the file.
SPDX Relationships are created to indicate dependencies between
CMake build targets; build targets that are linked together; and
source files that are compiled to generate the built library files.
`west spdx` can be called with optional parameters for further
configuration:
* `-n PREFIX`: specifies a prefix for the Document Namespaces that
will be included in the generated SPDX documents. See SPDX spec 2.2
section 2.5 at
https://spdx.github.io/spdx-spec/2-document-creation-information/.
If -n is omitted, a default namespace will be generated according
to the default format described in section 2.5 using a random UUID.
* `-s SPDX_DIR`: specifies an alternate directory where the SPDX
documents should be written. If not specified, they will be saved
in `BUILD_DIR/spdx/`.
* `--analyze-includes`: in addition to recording the compiled
source code files (e.g. `.c`, `.S`) in the bills-of-materials, if
this flag is specified, `west spdx` will attempt to determine the
specific header files that are included for each `.c` file. This
will take longer, as it performs a dry run using the C compiler
for each `.c` file (using the same arguments that were passed to it
for the actual build).
* `--include-sdk`: if `--analyze-includes` is used, then adding
`--include-sdk` will create a fourth SPDX document, `sdk.spdx`,
which will list any header files included from the SDK.
Signed-off-by: Steve Winslow <steve@swinslow.net>
Martí Bolívar