From a5f577d179e09e436b544bcbbb6b798a47f6c8b6 Mon Sep 17 00:00:00 2001
From: PKEuS <philipp.kloke@web.de>
Date: Mon, 26 Oct 2015 18:47:44 +0100
Subject: [PATCH] Support range-based for-loop in CheckClass::checkConst()
 (#5514)

---
 lib/checkclass.cpp |  4 ++++
 test/testclass.cpp | 17 +++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/checkclass.cpp b/lib/checkclass.cpp
index 87c97521e..6bf432150 100644
--- a/lib/checkclass.cpp
+++ b/lib/checkclass.cpp
@@ -1868,6 +1868,10 @@ bool CheckClass::checkConstFunc(const Scope *scope, const Function *func, bool&
                     if (lhs->previous()->variable()->typeStartToken()->strAt(-1) != "const" && lhs->previous()->variable()->isPointer())
                         return false;
                 }
+            } else if (lhs->str() == ":" && lhs->astParent() && lhs->astParent()->str() == "(" && tok1->strAt(1) == ")") { // range-based for-loop (C++11)
+                // TODO: We could additionally check what is done with the elements to avoid false negatives. Here we just rely on "const" keyword being used.
+                if (lhs->astParent()->strAt(1) != "const")
+                    return false;
             } else {
                 const Variable* v2 = lhs->previous()->variable();
                 if (lhs->tokType() == Token::eAssignmentOp && v2)
diff --git a/test/testclass.cpp b/test/testclass.cpp
index 4886371f5..c68efaf4a 100644
--- a/test/testclass.cpp
+++ b/test/testclass.cpp
@@ -170,6 +170,7 @@ private:
         TEST_CASE(constFriend); // ticket #1921 - fp for friend function
         TEST_CASE(constUnion);  // ticket #2111 - fp when there is a union
         TEST_CASE(constArrayOperator); // #4406
+        TEST_CASE(constRangeBasedFor); // #5514
 
         TEST_CASE(initializerListOrder);
         TEST_CASE(initializerListUsage);
@@ -5780,6 +5781,22 @@ private:
         ASSERT_EQUALS("[test.cpp:10]: (style, inconclusive) Technically the member function 'foo::c' can be const.\n", errout.str());
     }
 
+    void constRangeBasedFor() { // #5514
+        checkConst("class Fred {\n"
+                   "    int array[256];\n"
+                   "public:\n"
+                   "    void f1() {\n"
+                   "        for (auto & e : array)\n"
+                   "            foo(e);\n"
+                   "    }\n"
+                   "    void f2() {\n"
+                   "        for (const auto & e : array)\n"
+                   "            foo(e);\n"
+                   "    }\n"
+                   "};");
+        ASSERT_EQUALS("[test.cpp:8]: (style, inconclusive) Technically the member function 'Fred::f2' can be const.\n", errout.str());
+    }
+
     void checkInitializerListOrder(const char code[]) {
         // Clear the error log
         errout.str("");