fix(forge-lint): [unused imports] check doc cmnts (inheritdoc)

crates/lint/src/linter.rs

@@ -1,8 +1,8 @@
 use foundry_compilers::Language;
 use foundry_config::lint::Severity;
 use solar_ast::{
-    Expr, ImportDirective, ItemContract, ItemFunction, ItemStruct, SourceUnit, UsingDirective,
-    VariableDefinition, visit::Visit,
+    self as ast, Expr, ImportDirective, ItemContract, ItemFunction, ItemStruct, SourceUnit,
+    UsingDirective, VariableDefinition, visit::Visit,
 };
 use solar_interface::{
     Session, Span,
@@ -50,6 +50,10 @@ impl<'s> LintContext<'s> {
         Self { sess, with_description, inline_config: config }
     }
 
+    pub fn session(&self) -> &'s Session {
+        self.sess
+    }
+
     /// 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()) {
@@ -70,7 +74,7 @@ impl<'s> LintContext<'s> {
 }
 
 /// Trait for lints that operate directly on the AST.
-/// Its methods mirror `solar_ast::visit::Visit`, with the addition of `LintCotext`.
+/// Its methods mirror `ast::visit::Visit`, with the addition of `LintCotext`.
 pub trait EarlyLintPass<'ast>: Send + Sync {
     fn check_expr(&mut self, _ctx: &LintContext<'_>, _expr: &'ast Expr<'ast>) {}
     fn check_item_struct(&mut self, _ctx: &LintContext<'_>, _struct: &'ast ItemStruct<'ast>) {}
@@ -95,11 +99,12 @@ pub trait EarlyLintPass<'ast>: Send + Sync {
     }
     fn check_item_contract(&mut self, _ctx: &LintContext<'_>, _contract: &'ast ItemContract<'ast>) {
     }
+    fn check_doc_comment(&mut self, _ctx: &LintContext<'_>, _cmnt: &'ast ast::DocComment) {}
     // 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>) {}
+    fn check_full_source_unit(&mut self, _ctx: &LintContext<'ast>, _ast: &'ast SourceUnit<'ast>) {}
 }
 
 /// Visitor struct for `EarlyLintPass`es
@@ -126,6 +131,13 @@ where
 {
     type BreakValue = Never;
 
+    fn visit_doc_comment(&mut self, cmnt: &'ast ast::DocComment) -> ControlFlow<Self::BreakValue> {
+        for pass in self.passes.iter_mut() {
+            pass.check_doc_comment(self.ctx, cmnt)
+        }
+        self.walk_doc_comment(cmnt)
+    }
+
     fn visit_expr(&mut self, expr: &'ast Expr<'ast>) -> ControlFlow<Self::BreakValue> {
         for pass in self.passes.iter_mut() {
             pass.check_expr(self.ctx, expr)

crates/lint/src/sol/info/imports.rs

@@ -1,5 +1,6 @@
 use solar_ast::{self as ast, SourceUnit, Span, Symbol, visit::Visit};
 use solar_data_structures::map::FxIndexSet;
+use solar_interface::SourceMap;
 use std::ops::ControlFlow;
 
 use super::Imports;
@@ -36,22 +37,23 @@ impl<'ast> EarlyLintPass<'ast> for Imports {
         }
     }
 
-    fn check_full_source_unit(&mut self, ctx: &LintContext<'_>, ast: &'ast SourceUnit<'ast>) {
-        let mut checker = UnusedChecker::new();
+    fn check_full_source_unit(&mut self, ctx: &LintContext<'ast>, ast: &'ast SourceUnit<'ast>) {
+        let mut checker = UnusedChecker::new(ctx.session().source_map());
         let _ = checker.visit_source_unit(ast);
         checker.check_unused_imports(ast, ctx);
         checker.clear();
     }
 }
 
 /// Visitor that collects all used symbols in a source unit.
-struct UnusedChecker {
+struct UnusedChecker<'ast> {
     used_symbols: FxIndexSet<Symbol>,
+    source_map: &'ast SourceMap,
 }
 
-impl UnusedChecker {
-    fn new() -> Self {
-        Self { used_symbols: Default::default() }
+impl<'ast> UnusedChecker<'ast> {
+    fn new(source_map: &'ast SourceMap) -> Self {
+        Self { source_map, used_symbols: Default::default() }
     }
 
     fn clear(&mut self) {
@@ -93,7 +95,7 @@ impl UnusedChecker {
     }
 }
 
-impl<'ast> Visit<'ast> for UnusedChecker {
+impl<'ast> Visit<'ast> for UnusedChecker<'ast> {
     type BreakValue = solar_data_structures::Never;
 
     fn visit_item(&mut self, item: &'ast ast::Item<'ast>) -> ControlFlow<Self::BreakValue> {
@@ -154,4 +156,18 @@ impl<'ast> Visit<'ast> for UnusedChecker {
 
         self.walk_ty(ty)
     }
+
+    fn visit_doc_comment(
+        &mut self,
+        cmnt: &'ast solar_ast::DocComment,
+    ) -> ControlFlow<Self::BreakValue> {
+        if let Ok(snip) = self.source_map.span_to_snippet(cmnt.span) {
+            for line in snip.lines() {
+                if let Some((_, relevant)) = line.split_once("@inheritdoc") {
+                    self.mark_symbol_used(Symbol::intern(relevant.trim()));
+                }
+            }
+        }
+        ControlFlow::Continue(())
+    }
 }

crates/lint/testdata/Imports.sol

@@ -5,6 +5,9 @@ import {
     symbol3,
     symbol4,
     symbol5,
+    docSymbol,
+    docSymbol2,
+    docSymbolWrongTag, //~NOTE: unused imports should be removed
     eventSymbol,
     symbolNotUsed, //~NOTE: unused imports should be removed
     IContract,
@@ -35,13 +38,18 @@ import * as OtherUtils from "utils2.sol"; //~NOTE: unused imports should be remo
 contract UnusedImport is IContract {
     using mySymbol for address;
 
+    /// @inheritdoc docSymbol
     uint256 constant MY_CONSTANT = CONSTANT_0;
 
+    /**
+     * @inheritdoc docSymbol2
+     */
     struct FooBar {
         symbol3 foo;
         myOtherSymbol bar;
     }
 
+    /// @wrong docSymbolWrongTag
     SomeFile.Baz public myStruct;
     SomeFile2.Baz public myStruct2;
     symbol4 public myVar;

crates/lint/testdata/Imports.stderr

@@ -1,15 +1,15 @@
 note[unaliased-plain-import]: use named imports '{A, B}' or alias 'import ".." as X'
   --> ROOT/testdata/Imports.sol:LL:CC
    |
-25 | import "SomeFile.sol";
+28 | import "SomeFile.sol";
    |        --------------
    |
    = help: https://book.getfoundry.sh/reference/forge/forge-lint#unaliased-plain-import
 
 note[unaliased-plain-import]: use named imports '{A, B}' or alias 'import ".." as X'
   --> ROOT/testdata/Imports.sol:LL:CC
    |
-26 | import "AnotherFile.sol";
+29 | import "AnotherFile.sol";
    |        -----------------
    |
    = help: https://book.getfoundry.sh/reference/forge/forge-lint#unaliased-plain-import
@@ -23,49 +23,57 @@ note[unused-import]: unused imports should be removed
   = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
 
 note[unused-import]: unused imports should be removed
- --> ROOT/testdata/Imports.sol:LL:CC
-  |
-9 |     symbolNotUsed,
-  |     -------------
-  |
-  = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
+  --> ROOT/testdata/Imports.sol:LL:CC
+   |
+10 |     docSymbolWrongTag,
+   |     -----------------
+   |
+   = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
+
+note[unused-import]: unused imports should be removed
+  --> ROOT/testdata/Imports.sol:LL:CC
+   |
+12 |     symbolNotUsed,
+   |     -------------
+   |
+   = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
 
 note[unused-import]: unused imports should be removed
   --> ROOT/testdata/Imports.sol:LL:CC
    |
-11 |     IContractNotUsed
+14 |     IContractNotUsed
    |     ----------------
    |
    = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
 
 note[unused-import]: unused imports should be removed
   --> ROOT/testdata/Imports.sol:LL:CC
    |
-16 |     CONSTANT_1
+19 |     CONSTANT_1
    |     ----------
    |
    = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
 
 note[unused-import]: unused imports should be removed
   --> ROOT/testdata/Imports.sol:LL:CC
    |
-22 |     YetAnotherType
+25 |     YetAnotherType
    |     --------------
    |
    = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
 
 note[unused-import]: unused imports should be removed
   --> ROOT/testdata/Imports.sol:LL:CC
    |
-29 | import "another_file_2.sol" as AnotherFile2;
+32 | import "another_file_2.sol" as AnotherFile2;
    | --------------------------------------------
    |
    = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import
 
 note[unused-import]: unused imports should be removed
   --> ROOT/testdata/Imports.sol:LL:CC
    |
-32 | import * as OtherUtils from "utils2.sol";
+35 | import * as OtherUtils from "utils2.sol";
    | -----------------------------------------
    |
    = help: https://book.getfoundry.sh/reference/forge/forge-lint#unused-import