A tool for running Rust lints from dynamic libraries
sh
cargo install cargo-dylint --version '>=0.1.0-pre'
Dylint is a Rust linting tool, similar to Clippy. But whereas Clippy runs a predetermined, static set of lints, Dylint runs lints from user-specified, dynamic libraries. Thus, Dylint allows developers to have their own personal lint collections.
Contents
sh
cargo install cargo-dylint dylint-link --version '>=0.1.0-pre' # Install cargo-dylint and dylint-link
git clone https://github.com/trailofbits/dylint # Clone the Dylint repository
cd dylint/examples/allow_clippy # Go to one of the example lint libraries
cargo build # Build the library
cargo dylint allow_clippy -- --manifest-path ../../Cargo.toml # Run the library's lint on the Dylint source code
You can start writing your own Dylint libraries by forking the dylint-template repository.
When Dylint is started, the following locations are searched:
DYLINT_LIBRARY_PATH (if set)target/debug directory (if in a package)target/release directory (if in a package)Any file found in the above locations with a name of the form DLL_PREFIX LIBRARY_NAME '@' TOOLCHAIN DLL_SUFFIX (see Library requirements below) is considered a Dylint library.
In an invocation of the form cargo dylint <names>, each name in names is compared to the libraries found in the above manner. If name matches a discovered library's LIBRARY_NAME, then name resolves to that library. It is considered an error if a name resolves to multiple libraries.
If the above process does not resolve name to a library, then name is treated as a path.
If --lib name is used, then name is is treated only as a library name, and not as a path.
If --path name is used, then name is is treated only as a path, and not as a library name.
A Dylint library must satisfy four requirements. Note: before trying to satisfy these explicitly, see Utilities below.
Have a filename of the form:
DLL_PREFIX LIBRARY_NAME '@' TOOLCHAIN DLL_SUFFIX
The following is a concrete example on Linux:
libquestion_mark_in_expression@nightly-2021-03-11-x86_64-unknown-linux-gnu.so
The filename components are as follows:
DLL_PREFIX and DLL_SUFFIX are OS-specific strings. For example, on Linux, they are lib and .so, respectively.LIBARY_NAME is a name chosen by the library's author.TOOLCHAIN is the Rust toolchain for which the library is compiled, e.g., nightly-2021-03-11-x86_64-unknown-linux-gnu.Export a dylint_version function:
rust
extern "C" fn dylint_version() -> *mut std::os::raw::c_char
This function should return 0.1.0. This may change in future versions of Dylint.
Export a register_lints function:
rust
fn register_lints(sess: &rustc_session::Session, lint_store: &mut rustc_lint::LintStore)
This is a function called by the Rust compiler. It is documented here.
Link against the rustc_driver dynamic library. This ensures the library uses Dylint's copies of the Rust compiler crates. This requirement can be satisfied by including the following declaration in your library's lib.rs file:
rust
extern crate rustc_driver;
Dylint provides utilities to help meet the above requirements. If your library uses the dylint-link tool and the dylint_library! macro, then all you should have to do is implement the register_lints function.
The following utilities can be helpful for writing Dylint libraries:
dylint-link is a wrapper around Rust's default linker (cc) that creates a copy of your library with a filename that Dylint recognizes.dylint_library! is a macro that automatically defines the dylint_version function and adds the extern crate rustc_driver declaration.ui_test is a function that can be used to test Dylint libraries. It provides convenient access to the compiletest_rs package.clippy_utils is a collection of utilities to make writing lints easier. It is generously provided by the Rust Clippy Developers.Useful references for writing lints include:
rustc_hir documentation