1 files changed, 88 insertions, 0 deletions
diff --git a/compilerplugins/clang/selfinit.cxx b/compilerplugins/clang/selfinit.cxx
new file mode 100644
index 000000000..35ce37278
--- /dev/null
+++ b/compilerplugins/clang/selfinit.cxx
@@ -0,0 +1,88 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <vector>
+
+#include "plugin.hxx"
+
+// Warn when a variable is referenced from its own initializer.  This is not invalid in general (see
+// C++17 [basic.life]), but is at least suspicious.
+
+namespace
+{
+class SelfInit : public loplugin::FilteringPlugin<SelfInit>
+{
+public:
+    explicit SelfInit(loplugin::InstantiationData const& data)
+        : FilteringPlugin(data)
+    {
+    }
+
+    bool TraverseVarDecl(VarDecl* decl)
+    {
+        decls_.push_back({ decl, decl->getCanonicalDecl() });
+        auto const ret = FilteringPlugin::TraverseVarDecl(decl);
+        decls_.pop_back();
+        return ret;
+    }
+
+    bool TraverseUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr* expr)
+    {
+        if (expr->getKind() == UETT_SizeOf)
+        {
+            return true;
+        }
+        return FilteringPlugin::TraverseUnaryExprOrTypeTraitExpr(expr);
+    }
+
+    bool TraverseCXXTypeidExpr(CXXTypeidExpr const*) { return true; }
+
+    bool TraverseCXXNoexceptExpr(CXXNoexceptExpr const*) { return true; }
+
+    bool TraverseDecltypeTypeLoc(DecltypeTypeLoc) { return true; }
+
+    bool VisitDeclRefExpr(DeclRefExpr const* expr)
+    {
+        if (ignoreLocation(expr))
+        {
+            return true;
+        }
+        for (auto const& i : decls_)
+        {
+            if (expr->getDecl()->getCanonicalDecl() == i.canonical)
+            {
+                report(
+                    DiagnosticsEngine::Warning,
+                    ("referencing a variable during its own initialization is error-prone and thus"
+                     " suspicious"),
+                    expr->getLocation())
+                    << expr->getSourceRange();
+                report(DiagnosticsEngine::Note, "variable declared here", i.current->getLocation())
+                    << i.current->getSourceRange();
+            }
+        }
+        return true;
+    }
+
+private:
+    void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
+
+    struct Decl
+    {
+        VarDecl const* current;
+        VarDecl const* canonical;
+    };
+
+    std::vector<Decl> decls_;
+};
+
+loplugin::Plugin::Registration<SelfInit> X("selfinit");
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */