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-rw-r--r--compilerplugins/clang/stringviewdangle.cxx117
1 files changed, 117 insertions, 0 deletions
diff --git a/compilerplugins/clang/stringviewdangle.cxx b/compilerplugins/clang/stringviewdangle.cxx
new file mode 100644
index 000000000..99cb852d0
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+++ b/compilerplugins/clang/stringviewdangle.cxx
@@ -0,0 +1,117 @@
+/* -*- 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 <cassert>
+#include <string>
+#include <iostream>
+#include <unordered_map>
+#include <unordered_set>
+
+#include "plugin.hxx"
+#include "check.hxx"
+#include "compat.hxx"
+#include "config_clang.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/StmtVisitor.h"
+
+/**
+Look for places where we are assigning a temporary O[U]String to a std::*string_view, which leads
+to a view pointing to freed memory.
+*/
+
+namespace
+{
+class StringViewDangle : public loplugin::FilteringPlugin<StringViewDangle>
+{
+public:
+ explicit StringViewDangle(loplugin::InstantiationData const& data)
+ : FilteringPlugin(data)
+ {
+ }
+
+ bool preRun() override { return true; }
+
+ virtual void run() override
+ {
+ if (!preRun())
+ return;
+ TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+ }
+
+ bool VisitCXXOperatorCallExpr(CXXOperatorCallExpr const*);
+ bool VisitVarDecl(VarDecl const*);
+};
+
+static const Expr* IgnoreImplicitAndConversionOperator(const Expr* expr)
+{
+ expr = expr->IgnoreImplicit();
+ if (auto memberCall = dyn_cast<CXXMemberCallExpr>(expr))
+ {
+ if (auto conversionDecl = dyn_cast_or_null<CXXConversionDecl>(memberCall->getMethodDecl()))
+ {
+ if (!conversionDecl->isExplicit())
+ expr = memberCall->getImplicitObjectArgument()->IgnoreImpCasts();
+ }
+ }
+ return expr;
+}
+
+bool StringViewDangle::VisitCXXOperatorCallExpr(CXXOperatorCallExpr const* cxxOperatorCallExpr)
+{
+ if (ignoreLocation(cxxOperatorCallExpr))
+ return true;
+
+ auto op = cxxOperatorCallExpr->getOperator();
+ if (op != OO_Equal)
+ return true;
+ if (!loplugin::TypeCheck(cxxOperatorCallExpr->getType())
+ .ClassOrStruct("basic_string_view")
+ .StdNamespace())
+ return true;
+ auto expr = IgnoreImplicitAndConversionOperator(cxxOperatorCallExpr->getArg(1));
+ auto tc = loplugin::TypeCheck(expr->getType());
+ if (!tc.Class("OUString").Namespace("rtl").GlobalNamespace()
+ && !tc.Class("OString").Namespace("rtl").GlobalNamespace())
+ return true;
+ if (!isa<MaterializeTemporaryExpr>(expr))
+ return true;
+ report(DiagnosticsEngine::Warning, "view pointing into temporary i.e. dangling",
+ cxxOperatorCallExpr->getExprLoc())
+ << cxxOperatorCallExpr->getSourceRange();
+ return true;
+}
+
+bool StringViewDangle::VisitVarDecl(VarDecl const* varDecl)
+{
+ if (ignoreLocation(varDecl))
+ return true;
+ if (!loplugin::TypeCheck(varDecl->getType()).ClassOrStruct("basic_string_view").StdNamespace())
+ return true;
+ if (!varDecl->hasInit())
+ return true;
+ auto expr = IgnoreImplicitAndConversionOperator(varDecl->getInit());
+ auto tc = loplugin::TypeCheck(expr->getType());
+ if (!tc.Class("OUString").Namespace("rtl").GlobalNamespace()
+ && !tc.Class("OString").Namespace("rtl").GlobalNamespace())
+ return true;
+ if (!isa<MaterializeTemporaryExpr>(expr))
+ return true;
+ report(DiagnosticsEngine::Warning, "view pointing into temporary i.e. dangling",
+ varDecl->getLocation())
+ << varDecl->getSourceRange();
+ return true;
+}
+
+loplugin::Plugin::Registration<StringViewDangle> stringviewdangle("stringviewdangle");
+}
+
+#endif // LO_CLANG_SHARED_PLUGINS
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */