1 files changed, 136 insertions, 0 deletions
diff --git a/compilerplugins/clang/duplicate-defines.cxx b/compilerplugins/clang/duplicate-defines.cxx
new file mode 100644
index 000000000..74a95f2cc
--- /dev/null
+++ b/compilerplugins/clang/duplicate-defines.cxx
@@ -0,0 +1,136 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ */
+
+#include <cassert>
+#include <iostream>
+#include <unordered_map>
+
+#include "plugin.hxx"
+
+#include <clang/Frontend/CompilerInstance.h>
+#include <clang/Frontend/FrontendActions.h>
+#include <clang/Tooling/CommonOptionsParser.h>
+#include <clang/Tooling/Refactoring.h>
+#include <llvm/Support/Signals.h>
+
+/// Finds duplicated preprocessor defines, which generally indicate that some definition
+/// needs to be centralised somewhere.
+
+namespace
+{
+struct Entry
+{
+    clang::SourceLocation m_aLoc;
+};
+
+class DuplicateDefines : public clang::PPCallbacks, public loplugin::Plugin
+{
+public:
+    explicit DuplicateDefines(const loplugin::InstantiationData& data);
+    virtual void run() override;
+    void MacroDefined(const Token& MacroNameTok, const MacroDirective* MD) override;
+    void MacroUndefined(const Token& MacroNameTok, const MacroDefinition& MD,
+                        const MacroDirective* Undef) override;
+    enum
+    {
+        isPPCallback = true
+    };
+
+private:
+    clang::Preprocessor& m_rPP;
+    std::unordered_map<std::string, Entry> m_aDefMap;
+};
+
+DuplicateDefines::DuplicateDefines(const loplugin::InstantiationData& data)
+    : Plugin(data)
+    , m_rPP(compiler.getPreprocessor())
+{
+    compiler.getPreprocessor().addPPCallbacks(std::unique_ptr<PPCallbacks>(this));
+}
+
+void DuplicateDefines::run()
+{
+    // nothing, only check preprocessor usage
+}
+
+void DuplicateDefines::MacroDefined(const Token& rMacroNameTok, const MacroDirective*)
+{
+    auto aLoc = rMacroNameTok.getLocation();
+    if (ignoreLocation(aLoc))
+        return;
+
+    std::string aMacroName = m_rPP.getSpelling(rMacroNameTok);
+
+    // some testing macro
+    if (aMacroName == "RTL_STRING_CONST_FUNCTION")
+        return;
+    if (aMacroName == "rtl")
+        return;
+    // we replicate these macros in all the .hrc files
+    if (aMacroName == "NC_" || aMacroName == "NNC_")
+        return;
+    // We define this prior to including <windows.h>:
+    if (aMacroName == "WIN32_LEAN_AND_MEAN")
+    {
+        return;
+    }
+    // TODO no obvious fix for these
+    if (aMacroName == "FID_SEARCH_NOW" || aMacroName == "FID_SVX_START" || aMacroName == "FN_PARAM")
+        return;
+    // ignore for now, requires adding too many includes to sw/
+    if (aMacroName == "MM50")
+        return;
+
+    // ignore for now, we have the same define in svx and sw, but I can't remove one of them because
+    // they reference strings in different resource bundles
+    if (aMacroName == "STR_UNDO_COL_DELETE" || aMacroName == "STR_UNDO_ROW_DELETE"
+        || aMacroName == "STR_TABLE_NUMFORMAT" || aMacroName == "STR_DELETE")
+        return;
+
+    if (m_aDefMap.emplace(aMacroName, Entry{ aLoc }).second)
+    {
+        return;
+    }
+
+    // Happens e.g. with macros defined in include/premac.h, which is intended to be included
+    // (without include guards) multiple times:
+    auto const other = m_aDefMap[aMacroName].m_aLoc;
+    assert(aLoc == compiler.getSourceManager().getSpellingLoc(aLoc));
+    assert(other == compiler.getSourceManager().getSpellingLoc(other));
+    if ((compiler.getSourceManager().getFilename(aLoc)
+         == compiler.getSourceManager().getFilename(other))
+        && (compiler.getSourceManager().getSpellingLineNumber(aLoc)
+            == compiler.getSourceManager().getSpellingLineNumber(other))
+        && (compiler.getSourceManager().getSpellingColumnNumber(aLoc)
+            == compiler.getSourceManager().getSpellingColumnNumber(other)))
+    {
+        return;
+    }
+
+    report(DiagnosticsEngine::Warning, "duplicate defines", aLoc);
+    report(DiagnosticsEngine::Note, "previous define", other);
+}
+
+void DuplicateDefines::MacroUndefined(const Token& rMacroNameTok, const MacroDefinition& /*MD*/,
+                                      const MacroDirective* /*Undef*/)
+{
+    auto aLoc = rMacroNameTok.getLocation();
+    if (ignoreLocation(aLoc))
+        return;
+
+    std::string aMacroName = m_rPP.getSpelling(rMacroNameTok);
+    m_aDefMap.erase(aMacroName);
+}
+
+loplugin::Plugin::Registration<DuplicateDefines> X("duplicatedefines", true);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */