[slang-tidy] Fix NoOldAlwaysSyntax checker segmentation fault (#882)

Co-authored-by: Yan Churkin <[email protected]>
MikePopoloski · Jan 30, 2024 · 3afb0b6 · 3afb0b6
1 parent de03987
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diff --git a/tools/tidy/include/ASTHelperVisitors.h b/tools/tidy/include/ASTHelperVisitors.h
@@ -55,7 +55,8 @@ struct CollectIdentifiers : public slang::ast::ASTVisitor<CollectIdentifiers, fa
 /// ASTVisitor that will collect all LHS assignment symbols under a node
 struct CollectLHSSymbols : public slang::ast::ASTVisitor<CollectLHSSymbols, true, true> {
     void handle(const slang::ast::AssignmentExpression& expression) {
-        symbols.push_back(expression.left().getSymbolReference());
+        if (const auto symbol = expression.left().getSymbolReference(); symbol)
+            symbols.push_back(symbol);
     }
 
     std::vector<const slang::ast::Symbol*> symbols;

diff --git a/tools/tidy/tests/NoOldAlwaysSyntaxTest.cpp b/tools/tidy/tests/NoOldAlwaysSyntaxTest.cpp
@@ -199,3 +199,27 @@ endmodule
     bool result = visitor->check(root);
     CHECK(result);
 }
+
+TEST_CASE("NoOldAlwaysSyntax: composite lhs") {
+    auto tree = SyntaxTree::fromText(R"(
+module top();
+    logic n;
+
+    always @(*) begin
+        {n} = 1;
+    end
+endmodule
+)");
+
+    Compilation compilation;
+    compilation.addSyntaxTree(tree);
+    compilation.getAllDiagnostics();
+    auto& root = compilation.getRoot();
+
+    TidyConfig config;
+    Registry::setConfig(config);
+    Registry::setSourceManager(compilation.getSourceManager());
+    auto visitor = Registry::create("NoOldAlwaysSyntax");
+    bool result = visitor->check(root);
+    CHECK(result);
+}