lint: Add dylint-based linting framework

Author: jamie-osec

Cargo.lock

@@ -10,6 +10,7 @@ members = [
     "lang/derive/*",
     "lang/syn",
     "spl",
+    "lints/*",
 ]
 exclude = ["tests/cfo/deps/openbook-dex", "tests/swap/deps/openbook-dex"]
 resolver = "2"

Cargo.toml

@@ -45,6 +45,7 @@ use std::sync::LazyLock;
 
 mod checks;
 pub mod config;
+mod lint;
 pub mod rust_template;
 
 // Version of the docker image.
@@ -350,6 +351,16 @@ pub enum Command {
         #[clap(value_enum)]
         shell: clap_complete::Shell,
     },
+    /// Run Anchor lints on this workspace.
+    Lint {
+        // TODO: Once lints are published to GitHub, we shoud load from there by default
+        /// Path containing lint library packages
+        #[clap(long)]
+        path: String,
+        /// Subdirectories of the `--path` argument containing lint library packages
+        #[clap(long)]
+        pattern: String,
+    },
 }
 
 #[derive(Debug, Parser)]
@@ -915,6 +926,7 @@ fn process_command(opts: Opts) -> Result<()> {
             );
             Ok(())
         }
+        Command::Lint { path, pattern } => lint::run(&path, &pattern),
     }
 }
 

cli/src/lib.rs

@@ -0,0 +1,58 @@
+use std::process::Command;
+
+use anyhow::{bail, Context, Result};
+
+/// Runs Anchor-specific lints on the workspace
+pub fn run(path: &str, pattern: &str) -> Result<()> {
+    ensure_dylint()?;
+    let status = Command::new("cargo")
+        .args(["dylint", "--path", path, "--pattern", pattern])
+        .status()
+        .context("executing dylint")?;
+    if !status.success() {
+        bail!("dylint did not execute successfully");
+    }
+    Ok(())
+}
+
+/// Ensures dylint is installed
+fn ensure_dylint() -> Result<()> {
+    let output = Command::new("cargo")
+        .arg("install")
+        .arg("--list")
+        .output()?;
+    let mut has_cargo_dylint = false;
+    let mut has_dylint_link = false;
+    for line in String::from_utf8(output.stdout)
+        .context("parsing `cargo install --list` output")?
+        .lines()
+    {
+        let line = line.trim();
+        if line == "cargo-dylint" {
+            has_cargo_dylint = true;
+        } else if line == "dylint-link" {
+            has_dylint_link = true;
+        }
+        if has_cargo_dylint && has_dylint_link {
+            break;
+        }
+    }
+    if has_cargo_dylint && has_dylint_link {
+        return Ok(());
+    }
+
+    eprintln!("Installing required packages");
+    let mut cmd = Command::new("cargo");
+    cmd.arg("install");
+    if !has_cargo_dylint {
+        cmd.arg("cargo-dylint");
+    }
+    if !has_dylint_link {
+        cmd.arg("dylint-link");
+    }
+
+    if !cmd.status().context("installing dylint")?.success() {
+        bail!("installing dylint failed");
+    }
+    Ok(())
+}

cli/src/lint.rs

@@ -0,0 +1,6 @@
+[target.'cfg(all())']
+rustflags = ["-C", "linker=dylint-link"]
+
+# For Rust versions 1.74.0 and onward, the following alternative can be used
+# (see https://github.com/rust-lang/cargo/pull/12535):
+# linker = "dylint-link"

lints/example_lint/.cargo/config.toml

@@ -0,0 +1 @@
+/target

lints/example_lint/.gitignore

@@ -0,0 +1,20 @@
+[package]
+name = "example_lint"
+version = "0.1.0"
+authors = ["authors go here"]
+description = "description goes here"
+edition = "2024"
+publish = false
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+clippy_utils = { git = "https://github.com/rust-lang/rust-clippy", rev = "20ce69b9a63bcd2756cd906fe0964d1e901e042a" }
+dylint_linting = "5.0.0"
+
+[dev-dependencies]
+dylint_testing = "5.0.0"
+
+[package.metadata.rust-analyzer]
+rustc_private = true

lints/example_lint/Cargo.toml

@@ -0,0 +1,21 @@
+# `example_lint`
+
+### What it does
+
+Identifies `msg!("Hello, world!")` instances.
+
+### Why is this bad?
+
+It isn't, this is just a demo.
+
+### Example
+
+```rust
+msg!("Hello, world!");
+```
+
+Use instead:
+
+```rust
+msg!("Goodbye, world!");
+```

lints/example_lint/README.md

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "nightly-2025-09-18"
+components = ["llvm-tools-preview", "rustc-dev"]

lints/example_lint/rust-toolchain

@@ -0,0 +1,35 @@
+#![feature(rustc_private)]
+#![warn(unused_extern_crates)]
+
+extern crate rustc_hir;
+
+use clippy_utils::diagnostics::span_lint;
+use rustc_hir::{Expr, ExprKind, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+
+dylint_linting::declare_late_lint! {
+    #[doc = include_str!("../README.md")]
+    pub EXAMPLE_LINT,
+    Warn,
+    "use of `msg!(\"Hello, world!\")"
+}
+
+impl<'tcx> LateLintPass<'tcx> for ExampleLint {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
+        if let ExprKind::Call(target, args) = expr.kind
+            && let ExprKind::Path(QPath::Resolved(_, path)) = target.kind
+            && let Some(func) = &path.segments.last()
+            && func.ident.as_str() == "sol_log"
+            && let [arg] = &args
+            && let ExprKind::Lit(lit) = arg.kind
+            && lit.node.str().is_some_and(|s| s.as_str() == "Hello, world!")
+        {
+            span_lint(cx, EXAMPLE_LINT, expr.span.source_callsite(), "Use of `msg!(\"Hello, world!\")`");
+        }
+    }
+}
+
+#[test]
+fn ui() {
+    dylint_testing::ui_test(env!("CARGO_PKG_NAME"), "ui");
+}