New loplugin:stringconcat

Change-Id: Id7c517fb37bc28797c45fc0dde83e866f2aa4aac

1 files changed, 82 insertions, 0 deletions

diff --git a/compilerplugins/clang/stringconcat.cxx b/compilerplugins/clang/stringconcat.cxx
new file mode 100644
index 000000000000..43907e927cb3
--- /dev/null
+++ b/compilerplugins/clang/stringconcat.cxx
@@ -0,0 +1,82 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * 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 "plugin.hxx"
+
+namespace {
+
+class StringConcat:
+    public RecursiveASTVisitor<StringConcat>, public loplugin::Plugin
+{
+public:
+    explicit StringConcat(InstantiationData const & data): Plugin(data) {}
+
+    void run() override
+    { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
+
+    bool VisitCallExpr(CallExpr const * expr);
+};
+
+bool StringConcat::VisitCallExpr(CallExpr const * expr) {
+    if (ignoreLocation(expr)) {
+        return true;
+    }
+    FunctionDecl const * fdecl = expr->getDirectCallee();
+    if (fdecl == nullptr) {
+        return true;
+    }
+    OverloadedOperatorKind oo = fdecl->getOverloadedOperator();
+    if ((oo != OverloadedOperatorKind::OO_Plus
+         && oo != OverloadedOperatorKind::OO_LessLess)
+        || fdecl->getNumParams() != 2 || expr->getNumArgs() != 2
+        || !isa<StringLiteral>(expr->getArg(1)->IgnoreParenImpCasts()))
+    {
+        return true;
+    }
+    CallExpr const * left = dyn_cast<CallExpr>(
+        expr->getArg(0)->IgnoreParenImpCasts());
+    if (left == nullptr) {
+        return true;
+    }
+    FunctionDecl const * ldecl = left->getDirectCallee();
+    if (ldecl == nullptr) {
+        return true;
+    }
+    OverloadedOperatorKind loo = ldecl->getOverloadedOperator();
+    if ((loo != OverloadedOperatorKind::OO_Plus
+         && loo != OverloadedOperatorKind::OO_LessLess)
+        || ldecl->getNumParams() != 2 || left->getNumArgs() != 2
+        || !isa<StringLiteral>(left->getArg(1)->IgnoreParenImpCasts()))
+    {
+        return true;
+    }
+    StringRef name {
+        compiler.getSourceManager().getFilename(
+            compiler.getSourceManager().getSpellingLoc(expr->getLocStart())) };
+    if (name == SRCDIR "/sal/qa/rtl/strings/test_ostring_concat.cxx"
+        || name == SRCDIR "/sal/qa/rtl/strings/test_oustring_concat.cxx")
+    {
+        return true;
+    }
+    CXXOperatorCallExpr const * op = dyn_cast<CXXOperatorCallExpr>(expr);
+    report(
+        DiagnosticsEngine::Warning,
+        "replace '%0' between string literals with juxtaposition",
+        op == nullptr ? expr->getExprLoc() : op->getOperatorLoc())
+        << (oo == OverloadedOperatorKind::OO_Plus ? "+" : "<<")
+        << SourceRange(
+            left->getArg(1)->getLocStart(), expr->getArg(1)->getLocEnd());
+    return true;
+}
+
+loplugin::Plugin::Registration<StringConcat> X("stringconcat");
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */