loplugin:rangedforcopy: Assume non-reference structured binding is intentional

See pending <https://gerrit.libreoffice.org/c/core/+/149026> "tdf#148008: do not
proceed after the marked range" for a use case.

Change-Id: Ief7cbb215068b6f5428c16a72896ef5612204128
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/149056
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

2 files changed, 35 insertions, 0 deletions

diff --git a/compilerplugins/clang/rangedforcopy.cxx b/compilerplugins/clang/rangedforcopy.cxx
index 01124bb4d117..b0ab6bf35027 100644
--- a/compilerplugins/clang/rangedforcopy.cxx
+++ b/compilerplugins/clang/rangedforcopy.cxx
@@ -45,6 +45,11 @@ bool RangedForCopy::VisitCXXForRangeStmt( const CXXForRangeStmt* stmt )
     const VarDecl* varDecl = stmt->getLoopVariable();
     if (!varDecl)
       return true;
+    if (isa<DecompositionDecl>(varDecl))
+    {
+        // Assume that use of a non-reference structured binding is intentional:
+        return true;
+    }
 
     const QualType type = varDecl->getType();
     if (type->isRecordType() && !type->isReferenceType() && !type->isPointerType())
diff --git a/compilerplugins/clang/test/rangedforcopy.cxx b/compilerplugins/clang/test/rangedforcopy.cxx
new file mode 100644
index 000000000000..f4346b18111d
--- /dev/null
+++ b/compilerplugins/clang/test/rangedforcopy.cxx
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * 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/.
+ */
+
+struct S
+{
+    int i1;
+    int i2;
+};
+
+void f(S const (&a)[2])
+{
+    // expected-error-re@+1 {{Loop variable passed by value, pass by reference instead, e.g. 'const {{(struct )?}}S&' [loplugin:rangedforcopy]}}
+    for (auto i : a)
+    {
+        (void)i;
+    }
+    for (auto[i1, i2] : a)
+    {
+        (void)i1;
+        (void)i2;
+    }
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */