Fix #14888 FP functionConst with array to pointer decay

Author: web-flow

lib/checkclass.cpp

@@ -2608,9 +2608,12 @@ bool CheckClassImpl::checkConstFunc(const Scope *scope, const Function *func, Me
                     return false;
             } else {
                 if (lhs->isAssignmentOp()) {
-                    const Variable* lhsVar = lhs->previous()->variable();
-                    if (lhsVar && !lhsVar->isConst() && lhsVar->isReference() && lhs == lhsVar->nameToken()->next())
-                        return false;
+                    if (const Variable* lhsVar = lhs->previous()->variable()) {
+                        if (!lhsVar->isConst() && lhsVar->isReference() && lhs == lhsVar->nameToken()->next())
+                            return false;
+                        if (lhsVar->isPointer() && v->isArray() && !(lhsVar->valueType() && lhsVar->valueType()->isConst(/*indirect*/ 1)))
+                            return false;
+                    }
                 }
             }
 

test/testclass.cpp

@@ -196,6 +196,7 @@ class TestClass : public TestFixture {
         TEST_CASE(const99);
         TEST_CASE(const100);
         TEST_CASE(const101);
+        TEST_CASE(const102);
 
         TEST_CASE(const_handleDefaultParameters);
         TEST_CASE(const_passThisToMemberOfOtherClass);
@@ -6998,6 +6999,22 @@ class TestClass : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void const102() {
+        checkConst("struct S {\n" // #14888
+                   "    void f() {\n"
+                   "        int *p = a;\n"
+                   "        *p = 0;\n"
+                   "    }\n"
+                   "    void g() {\n"
+                   "        const int *p = a;\n"
+                   "        if (*p) {}\n"
+                   "    }\n"
+                   "    int a[3];\n"
+                   "};\n");
+        ASSERT_EQUALS("[test.cpp:6:10]: (style, inconclusive) Technically the member function 'S::g' can be const. [functionConst]\n",
+                      errout_str());
+    }
+
     void const_handleDefaultParameters() {
         checkConst("struct Foo {\n"
                    "    void foo1(int i, int j = 0) {\n"