3daeeaefb1
The principle of this is that you can either externally build it with Nix (actual implementation will be in a future commit), or it can be built with meson if the Nix one is not passed in. The idea I have is that dev shells don't receive the one from Nix to avoid having to build it, but CI can use the one from Nix and save some gratuitous rebuilds. The design of this is that you can run `ninja -C build clang-tidy` and it will simply correctly clang-tidy the codebase in spite of PCH bullshit caused by the cc-wrapper. This is a truly horrendous number of hacks in a ball, caused by bugs in several pieces of software, and I am not even getting started. I don't consider this to fix the clang-tidy issue filing, since we still have a fair number of issues to fix even on the existing minimal configuration, and I have not yet implemented it in CI. Realistically we will need to do something like https://github.com/Ericsson/codechecker to be able to silence warnings without physically touching the code, or at least *diff* reports between versions. Also, the run-clang-tidy output design is rather atrocious and must not be inflicted upon anyone I have respect for, since it buries the diagnostics in a pile of invocation logs. We would do really well to integrate with the Gerrit SARIF stuff so we can dump the reports on people in a user-friendly manner. Related: https://git.lix.systems/lix-project/lix/issues/147 Change-Id: Ifefe533f3b56874795de231667046b2da6ff2461
56 lines
2 KiB
Markdown
56 lines
2 KiB
Markdown
# Clang tidy lints for Lix
|
|
|
|
This is a skeleton of a clang-tidy lints library for Lix.
|
|
|
|
Currently there is one check (which is already obsolete as it has served its
|
|
goal and is there as an example), `HasPrefixSuffixCheck`.
|
|
|
|
## Running fixes/checks
|
|
|
|
One file:
|
|
|
|
```
|
|
ninja -C build && clang-tidy --checks='-*,lix-*' --load=build/liblix-clang-tidy.so -p ../compile_commands.json -header-filter '\.\./src/.*\.h' --fix ../src/libcmd/installables.cc
|
|
```
|
|
|
|
Several files, in parallel:
|
|
|
|
```
|
|
ninja -C build && run-clang-tidy -checks='-*,lix-*' -load=build/liblix-clang-tidy.so -p .. -header-filter '\.\./src/.*\.h' -fix ../src | tee -a clang-tidy-result
|
|
```
|
|
|
|
## Resources
|
|
|
|
* https://firefox-source-docs.mozilla.org/code-quality/static-analysis/writing-new/clang-query.html
|
|
* https://clang.llvm.org/docs/LibASTMatchersReference.html
|
|
* https://devblogs.microsoft.com/cppblog/exploring-clang-tooling-part-3-rewriting-code-with-clang-tidy/
|
|
|
|
## Developing new checks
|
|
|
|
Put something like so in `myquery.txt`:
|
|
|
|
```
|
|
set traversal IgnoreUnlessSpelledInSource
|
|
# ^ Ignore implicit AST nodes. May need to use AsIs depending on how you are
|
|
# working.
|
|
set bind-root true
|
|
# ^ true unless you use any .bind("foo") commands
|
|
set print-matcher true
|
|
enable output dump
|
|
match callExpr(callee(functionDecl(hasName("hasPrefix"))), optionally(hasArgument( 0, cxxConstructExpr(hasDeclaration(functionDecl(hasParameter(0, parmVarDecl(hasType(asString("const char *"))).bind("meow2"))))))))
|
|
```
|
|
|
|
Then run, e.g. `clang-query --preload hasprefix.query -p compile_commands.json src/libcmd/installables.cc`.
|
|
|
|
With this you can iterate a query before writing it in C++ and suffering from
|
|
C++.
|
|
|
|
### Tips and tricks for the C++
|
|
|
|
There is a function `dump()` on many things that will dump to stderr. Also
|
|
`llvm::errs()` lets you print to stderr.
|
|
|
|
When I wrote `HasPrefixSuffixCheck`, I was not really able to figure out how
|
|
the structured replacement system was supposed to work. In principle you can
|
|
describe the replacement with a nice DSL. Look up the Stencil system in Clang
|
|
for details.
|