1 files changed, 156 insertions, 0 deletions
diff --git a/compilerplugins/clang/stringconcatliterals.cxx b/compilerplugins/clang/stringconcatliterals.cxx
new file mode 100644
index 000000000..2e89ddca6
--- /dev/null
+++ b/compilerplugins/clang/stringconcatliterals.cxx
@@ -0,0 +1,156 @@
+/* -*- 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/.
+ */
+
+#ifndef LO_CLANG_SHARED_PLUGINS
+
+#include "config_clang.h"
+
+#include "plugin.hxx"
+#include "check.hxx"
+
+namespace {
+
+Expr const * stripCtor(Expr const * expr) {
+    auto e1 = expr;
+    if (auto const e = dyn_cast<CXXFunctionalCastExpr>(e1)) {
+        e1 = e->getSubExpr()->IgnoreParenImpCasts();
+    }
+    if (auto const e = dyn_cast<CXXBindTemporaryExpr>(e1)) {
+        e1 = e->getSubExpr()->IgnoreParenImpCasts();
+    }
+    auto const e2 = dyn_cast<CXXConstructExpr>(e1);
+    if (e2 == nullptr) {
+        return expr;
+    }
+    auto qt = loplugin::DeclCheck(e2->getConstructor());
+    if (qt.MemberFunction().Class("OStringLiteral").Namespace("rtl").GlobalNamespace()
+        || qt.MemberFunction().Class("OUStringLiteral").Namespace("rtl").GlobalNamespace())
+    {
+        if (e2->getNumArgs() == 1) {
+            return e2->getArg(0)->IgnoreParenImpCasts();
+        }
+        return expr;
+    }
+    if (!((qt.MemberFunction().Class("OString").Namespace("rtl")
+           .GlobalNamespace())
+          || (qt.MemberFunction().Class("OUString").Namespace("rtl")
+              .GlobalNamespace())))
+    {
+        return expr;
+    }
+    if (e2->getNumArgs() != 2) {
+        return expr;
+    }
+    return e2->getArg(0)->IgnoreParenImpCasts();
+}
+
+class StringConcatLiterals:
+    public loplugin::FilteringPlugin<StringConcatLiterals>
+{
+public:
+    explicit StringConcatLiterals(loplugin::InstantiationData const & data):
+        FilteringPlugin(data) {}
+
+    void run() override
+    { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
+
+    bool VisitCallExpr(CallExpr const * expr);
+
+private:
+    bool isStringLiteral(Expr const * expr);
+};
+
+bool StringConcatLiterals::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
+        || !isStringLiteral(expr->getArg(1)->IgnoreParenImpCasts()))
+    {
+        return true;
+    }
+    SourceLocation leftLoc;
+    auto const leftExpr = expr->getArg(0)->IgnoreParenImpCasts();
+    if (isStringLiteral(leftExpr)) {
+        leftLoc = leftExpr->getBeginLoc();
+    } else {
+        CallExpr const * left = dyn_cast<CallExpr>(leftExpr);
+        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
+            || !isStringLiteral(left->getArg(1)->IgnoreParenImpCasts()))
+        {
+            return true;
+        }
+        leftLoc = left->getArg(1)->getBeginLoc();
+    }
+
+    // We add an extra " " in the TOOLS_WARN_EXCEPTION macro, which triggers this plugin
+    if (loplugin::isSamePathname(
+            getFilenameOfLocation(
+                compiler.getSourceManager().getSpellingLoc(
+                    compiler.getSourceManager().getImmediateMacroCallerLoc(
+                        compiler.getSourceManager().getImmediateMacroCallerLoc(
+                            compiler.getSourceManager().getImmediateMacroCallerLoc(
+                                expr->getBeginLoc()))))),
+            SRCDIR "/include/tools/diagnose_ex.h"))
+        return true;
+
+    StringRef name {
+        getFilenameOfLocation(
+            compiler.getSourceManager().getSpellingLoc(expr->getBeginLoc())) };
+    if (loplugin::isSamePathname(
+            name, SRCDIR "/sal/qa/rtl/oustringbuffer/test_oustringbuffer_assign.cxx")
+        || loplugin::isSamePathname(
+            name, SRCDIR "/sal/qa/rtl/strings/test_ostring_concat.cxx")
+        || loplugin::isSamePathname(
+            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(leftLoc, expr->getArg(1)->getEndLoc());
+    return true;
+}
+
+bool StringConcatLiterals::isStringLiteral(Expr const * expr) {
+    expr = stripCtor(expr);
+    if (!isa<clang::StringLiteral>(expr)) {
+        return false;
+    }
+    return true;
+}
+
+loplugin::Plugin::Registration<StringConcatLiterals> stringconcatliterals("stringconcatliterals");
+
+} // namespace
+
+#endif // LO_CLANG_SHARED_PLUGINS
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */