feat(forge lint): unused imports

Cargo.toml

@@ -211,6 +211,7 @@ solar-ast = { version = "=0.1.4", default-features = false }
 solar-parse = { version = "=0.1.4", default-features = false }
 solar-interface = { version = "=0.1.4", default-features = false }
 solar-sema = { version = "=0.1.4", default-features = false }
+solar-data-structures = { version = "=0.1.4", default-features = false }
 
 ## alloy
 alloy-consensus = { version = "1.0.11", default-features = false }
@@ -410,3 +411,10 @@ zip-extract = "=0.2.1"
 ## foundry
 # foundry-compilers = { git = "https://github.com/foundry-rs/compilers.git", rev = "e4a9b04" }
 # foundry-fork-db = { git = "https://github.com/foundry-rs/foundry-fork-db", rev = "811a61a" }
+
+# solar
+solar-ast = { git = "https://github.com/paradigmxyz/solar.git", branch = "main" }
+solar-parse = { git = "https://github.com/paradigmxyz/solar.git", branch = "main" }
+solar-interface = { git = "https://github.com/paradigmxyz/solar.git", branch = "main" }
+solar-sema = { git = "https://github.com/paradigmxyz/solar.git", branch = "main" }
+solar-data-structures = { git = "https://github.com/paradigmxyz/solar.git", branch = "main" }

crates/lint/Cargo.toml

@@ -22,6 +22,7 @@ foundry-config.workspace = true
 solar-parse.workspace = true
 solar-ast.workspace = true
 solar-interface = { workspace = true, features = ["json"] }
+solar-data-structures.workspace = true
 
 heck.workspace = true
 rayon.workspace = true

crates/lint/src/linter.rs

@@ -1,6 +1,9 @@
 use foundry_compilers::Language;
 use foundry_config::lint::Severity;
-use solar_ast::{visit::Visit, Expr, ItemFunction, ItemStruct, VariableDefinition};
+use solar_ast::{
+    visit::Visit, Expr, ImportDirective, ItemContract, ItemFunction, ItemStruct, SourceUnit,
+    UsingDirective, VariableDefinition,
+};
 use solar_interface::{
     data_structures::Never,
     diagnostics::{DiagBuilder, DiagId, MultiSpan},
@@ -47,7 +50,7 @@ impl<'s> LintContext<'s> {
         Self { sess, with_description, inline_config: config }
     }
 
-    // Helper method to emit diagnostics easily from passes
+    /// Helper method to emit diagnostics easily from passes
     pub fn emit<L: Lint>(&self, lint: &'static L, span: Span) {
         if self.inline_config.is_disabled(span, lint.id()) {
             return;
@@ -78,8 +81,25 @@ pub trait EarlyLintPass<'ast>: Send + Sync {
         _var: &'ast VariableDefinition<'ast>,
     ) {
     }
-
+    fn check_import_directive(
+        &mut self,
+        _ctx: &LintContext<'_>,
+        _import: &'ast ImportDirective<'ast>,
+    ) {
+    }
+    fn check_using_directive(
+        &mut self,
+        _ctx: &LintContext<'_>,
+        _using: &'ast UsingDirective<'ast>,
+    ) {
+    }
+    fn check_item_contract(&mut self, _ctx: &LintContext<'_>, _contract: &'ast ItemContract<'ast>) {
+    }
     // TODO: Add methods for each required AST node type
+
+    /// Should be called after the source unit has been visited. Enables lints that require
+    /// knowledge of the entire AST to perform their analysis.
+    fn check_full_source_unit(&mut self, _ctx: &LintContext<'_>, _ast: &'ast SourceUnit<'ast>) {}
 }
 
 /// Visitor struct for `EarlyLintPass`es
@@ -88,6 +108,18 @@ pub struct EarlyLintVisitor<'a, 's, 'ast> {
     pub passes: &'a mut [Box<dyn EarlyLintPass<'ast> + 's>],
 }
 
+/// Extends the [`Visit`] trait functionality with a hook that can run after the initial traversal.
+impl<'s, 'ast> EarlyLintVisitor<'_, 's, 'ast>
+where
+    's: 'ast,
+{
+    pub fn post_source_unit(&mut self, ast: &'ast SourceUnit<'ast>) {
+        for pass in self.passes.iter_mut() {
+            pass.check_full_source_unit(self.ctx, ast);
+        }
+    }
+}
+
 impl<'s, 'ast> Visit<'ast> for EarlyLintVisitor<'_, 's, 'ast>
 where
     's: 'ast,
@@ -131,6 +163,36 @@ where
         self.walk_item_function(func)
     }
 
+    fn visit_import_directive(
+        &mut self,
+        import: &'ast ImportDirective<'ast>,
+    ) -> ControlFlow<Self::BreakValue> {
+        for pass in self.passes.iter_mut() {
+            pass.check_import_directive(self.ctx, import);
+        }
+        self.walk_import_directive(import)
+    }
+
+    fn visit_using_directive(
+        &mut self,
+        using: &'ast UsingDirective<'ast>,
+    ) -> ControlFlow<Self::BreakValue> {
+        for pass in self.passes.iter_mut() {
+            pass.check_using_directive(self.ctx, using);
+        }
+        self.walk_using_directive(using)
+    }
+
+    fn visit_item_contract(
+        &mut self,
+        contract: &'ast ItemContract<'ast>,
+    ) -> ControlFlow<Self::BreakValue> {
+        for pass in self.passes.iter_mut() {
+            pass.check_item_contract(self.ctx, contract);
+        }
+        self.walk_item_contract(contract)
+    }
+
     // TODO: Add methods for each required AST node type, mirroring `solar_ast::visit::Visit` method
     // sigs + adding `LintContext`
 }