Running clang analyzer with bazel
Summary
This repository contains scripts for running the clang
analyzer static
analysis tool in a bazel workspace. It is forked from this
gist. The key point
is the generation of a clang compilation
database file. This
file is useful for many other tools as well, such as clang-tidy.
Installation and setup
Place the full contents of this repo into a suitable folder in your bazel
workspace. For installation purposes assume they are in REPO_ROOT/tools/actions.
You will need the python library scan-build, which you can install with:
pip install scan-build
Setup is not at all stable. You may run into strange permissions and paths
issues when executing. Sorry! If you don't
use the paths assumed here, you'll have to change the import paths in
generate_compile_command.py. On the other hand,
generate_compile_commands_json.py should work as is. If you use
run_clang_analyzer.sh, you will probably need to change or remove the
--use-analyzer option depending on what clang you use, and whether you use a
wrapper script for it.
Usage
Before running static analysis tools, you must generate the compilation commands database. Assuming you set up the targets as above, you can do this with:
# From repository root:
bazel clean
bazel build --experimental_action_listener=tools/actions:generate_compile_commands_listener BAZEL_LABELS
python3 ./tools/actions/generate_compile_commands_json.py
This creates the compilation database file in the repository root with the name
compile_commands.json. Other clang tools like clang-tidy also like this
file!
To get a static analysis repot, just call analyze-build, which was installed
with the scan-build python package:
analyze-build --cdb compile_commands.json -o clang-analysis --html-title "My Report"
This generates html files in clang-analysis/scan-xxx, which you can serve or view with a tool of your choice.
Gotchas
If you use a bazel externalized crosstool (instead of just one in /usr/bin),
you'll have to pass in the compiler path to analyze-build using the
--use-analyzer option. In addition, you might have problems with bazel's crazy
source tree. In my repository, I had to execute analyze-build from the bazel
execution_root:
REPO_ROOT=$PWD
cd `bazel info execution_root`
analyze-build --cdb $REPO_ROOT/compile_commands.json -o $REPO_ROOT/clang-analysis --html-title "My Report" --use-analyzer external/clang_3_8/usr/bin/clang-3.8
In addition, bazel may set strange permissions on the bazel cache, so sudo may
be required on your analyze-build command.
The script run_clang_analyzer.sh contains an example workflow. Use like this:
./run_clang_analyzer.sh //bazel/targets/...
Status
This has been modified from the original version by cybrown-zoox to make it slightly easier to include and use. It fixes a bug in the original and includes some of the necessary bits that were not originally included.