1 files changed, 68 insertions, 0 deletions
diff --git a/gcc/rust/lint/rust-lint-scan-deadcode.h b/gcc/rust/lint/rust-lint-scan-deadcode.h
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+// Copyright (C) 2021 Free Software Foundation, Inc.
+
+// This file is part of GCC.
+
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+// for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef RUST_HIR_SCAN_DEADCODE
+#define RUST_HIR_SCAN_DEADCODE
+
+#include <set>
+#include "rust-hir-full-decls.h"
+#include "rust-hir-map.h"
+#include "rust-lint-marklive-base.h"
+#include "rust-name-resolver.h"
+#include "rust-diagnostics.h"
+
+namespace Rust {
+namespace Analysis {
+
+class ScanDeadcode : public MarkLiveBase
+{
+  using Rust::Analysis::MarkLiveBase::visit;
+
+public:
+  static void Scan (HIR::Crate &crate, std::set<HirId> live_symbols)
+  {
+    ScanDeadcode sdc (live_symbols);
+    for (auto it = crate.items.begin (); it != crate.items.end (); it++)
+      {
+	it->get ()->accept_vis (sdc);
+      }
+  };
+
+  void visit (HIR::Function &function) override
+  {
+    HirId hirId = function.get_mappings ().get_hirid ();
+    if (live_symbols.find (hirId) == live_symbols.end ())
+      {
+	rust_warning_at (function.get_locus (), 0,
+			 "function is never used: `%s`",
+			 function.get_function_name ().c_str ());
+	return;
+      }
+  }
+
+private:
+  std::set<HirId> live_symbols;
+  // std::set<HirId> dead_codes;
+
+  ScanDeadcode (std::set<HirId> &live_symbols) : live_symbols (live_symbols){};
+};
+
+} // namespace Analysis
+} // namespace Rust
+
+#endif
+\ No newline at end of file